Wikiversity enwikiversity https://en.wikiversity.org/wiki/Wikiversity:Main_Page MediaWiki 1.39.0-wmf.23 first-letter Media Special Talk User User talk Wikiversity Wikiversity talk File File talk MediaWiki MediaWiki talk Template Template talk Help Help talk Category Category talk School School talk Portal Portal talk Topic Topic talk Collection Collection talk Draft Draft talk TimedText TimedText talk Module Module talk Gadget Gadget talk Gadget definition Gadget definition talk 4 1558 2413991 2412428 2022-08-12T16:58:53Z 148.234.92.119 Just a line at a time wikitext text/x-wiki {{Please leave this line alone (sandbox heading)}} Here you add content!<!-- Hello! Feel free to try your formatting and editing skills below this line. As this page is for editing experiments, this page will automatically be cleaned periodically. --> eupleweghfpr9syp3mqmkl5cx8s9p09 0 39427 2414013 2198405 2022-08-12T23:09:46Z 95.215.11.65 The format of the math on the page was confusing and an answer to a particular function was in the wrong place on the page wikitext text/x-wiki {{mathematics}} {{lesson}} One of the most neglected topics in high school is the study of functions. In this lesson there are three rather lengthy chapters directly related to functions and several others that are indirectly related. There are two reasons for this: functions are important, and most calculus courses assume you know this topic almost perfectly, an unrealistic assumption. So let's get started at the beginning. ==Introduction== We will start with an excruciatingly theoretical and general definition of a function in mathematics, and then look at the topic in a more down-to-Earth way. ''Function'': Given a set D. To each element in D, we assign one and only one element. '''Example 1''' The table below represents a function. 1 maps to a, 2 maps to 3, 3 maps to 3, and 4 maps to "pig". Each element in D is assigned one and only one element. :::<math>D\ \ \ R\,</math> :::<math>1 \to a</math> :::<math>2 \to 3</math> :::<math>3 \to 3</math> :::<math>4 \to </math>&nbsp;"pig" The set D is called the ''domain''. There is a second set that arises, called the ''range''. Notice that the domain and the range can contain the same thing (the number 3) or vastly different things (3 and "pig"). The domain and range are arbitrary mathematical sets. In this example, the domain is the set of integers 1 to 4, and the range might be the union of the set of integers, the set of letters, and the set of farm animals. :<math>D = \{\text{integers from 1 to 4}\}\,</math> :<math>R = \{\text{integers}\} \cup \{\text{letters}\} \cup \{\text{farm animals}\}</math> The rule (the arrows in the table above) is called the ''map'' or ''mapping''. 1 is mapped into a; 2 is mapped into 3; 3 is mapped into 3; and 4 is mapped into "pig". The true theoretical definition of a function is: A function is a domain, a range, and set of ordered pairs such that *The first item in each pair is an element of the domain. *The second item is an element of the range. *No two pairs have the same first element. This property is sometimes expressed by saying that a function must be ''single valued''. *Every element in the domain appears as the first item of one (and only one) of the pairs. In this example, the set of ordered pairs would be :<math>\{ (1, a), (2, 3), (3, 3), (4, \text{pig}) \}\,</math> A few things to note: *It is perfectly legitimate for an element of the range to appear as the second item in more than one pair. That is, multiple domain elements can map to the same range element. *Not every element of the range needs to appear as the second item in some pair. That is, there can be elements of the range that nothing maps to. In this example, no number maps to "cow", even though the range includes all farm animals. The subset of the range that consists only of those elements that ''do'' get mapped to is called the ''image''. We will say more about that later.<ref>Some authors use the term "range" to refer only to those items that are actually mapped to, rather than those items that ''could potentially'' be mapped to. That is, they us the terms "range" and "image" interchangeably. It's not important in practice. The "image" is the set that is important, and its meaning is unambiguous. It is the set of just those elements that are actually mapped to.</ref> '''Example 2''' This does not represent a function, since 1 would map to both a and d. It is not single-valued. :<math>\{ (1, a), (1, d), (2, e), (3, f), (4, g) \}\,</math> ==Function's Notation== :[[Image:functionEx.png|right|300 px|Visualizing functions.]] The first depicts a function as sort of a "machine" that receives inputs and emits outputs. This is sometimes useful when dealing with composition of functions, as discussed below. The second depicts a function in terms of arrows going from points in the domain to points in the range. The diagram shows just 3 points in some very abstract representations of the domain and range. If the function defined earlier is denoted f, we say: f(1) = a (read "f of 1 equals a"); f(2) = 3; f(3) = 3; and f(4) = "pig". Mathematical notation :<math>f(x)=y</math> Where :<math>f(x)</math> - Function of variable x :<math>x</math> - Function's variable :<math>y</math> - Function's value ==Function Definition by a Rule== The definition of functions in terms of sets of ordered pairs is suitable only for abstract discussions of set theory. In practice, functions are usually defined by giving a ''rule'', and having the domain and range be numbers. For example, here is a definition of a function whose domain and range are the real numbers: :<math>f(x) = x^2+4x+7 \,</math> If x is 2 then :<math>f(x) = 2^2+4 \times 2+7 \ = 4 + 8 + 7 = 19</math> ==Functions as Graphs== A way of visualizing functions that is extremely useful in practical situations, is as a graph. It only works for functions from real numbers to real numbers, but that is an extremely common case. The x-axis of the graph shows the domain, and the y-axis shows the range. A line of the required shape shows the function values (that is, y-values) for any given x-value. The diagram below shows this (simultaneously) for two well-known trigonometric functions. The [[Trigonometry/Functions#Sine|sine]] function is shown in red, and the cosine function in blue. Horizontal and vertical divisions are each 0.5. : <math>f(x)=Sin x</math> . In red : <math>f(x)=Cos x</math> . In blue : [[Image:Sincosgraph.png|400 px|Graphs of the sine (red) and cosine (blue) functions.]] Looking at the graph of a function makes it very easy to see a number of interesting characteristics, such as continuity. One can also estimate the derivative. For example, the graph on the right makes it quite plausible (and it is in fact true) that the derivative of the sine is the cosine, and the derivative of the cosine is the negative of the sine. Inspection of a graph can also make it clear when a purported function does not satisfy the requirement of single-valuedness. A vertical line should cut the graph in only one place. The graph labeled "No" clearly doesn't satisfy that. One can see that it attempts to have f(p)&nbsp;=&nbsp;q and f(p)&nbsp;=&nbsp;r, which is not allowed. :[[Image:vtlinetest1.jpg|200px]] [[Image:vtlinetest2.jpg|200px]] {{clear}} '''Example 3''' Let <math>y = f(x) = x^2+4x+7 \,</math>. The possible values of <math>x\,</math> form the domain. Let us assume that there are only three possible values of <math>x\,</math>, that is, <math> \mathcal{D} = \{1,-3,10\}\,</math>. Then, the function <math>f(x)\,</math> converts these three values of <math>x\,</math> into three different values of <math>y\,</math> which form the set <math>\mathcal{R}</math>. The set <math>\mathcal{R}</math> is called the ''range'' of the function. In this example, the three values that form the set <math>\mathcal{R}</math> are found to be :<math> \begin{align} f(1) & = (1)^2+4(1)+7 = 12 \\ f(-3) & = (-3)^2+4(-3)+7 = 4 \\ f(10) & = (10)^2+4(10)+7 = 147 \end{align} </math> Therefore the range is <math> \mathcal{R} \equiv \{4,12,147\}</math>. If we were to draw the points <math>[x, f(x)]\,</math> on a graph, we would have to graph (1,12), (-3,4) and (10,147). '''NOTE''' Instead of graphing points (x,y), we are graphing points (x,f(x)). For our purposes, the notation is different, but the meanings are the same. '''Example 4''' Let g(x) = x²-5x-9. D = {4,0,-3,<math>a^4</math>,x+h}. Find the elements in the range. This is a pretty crazy example, but there are reasons to do it. g(4) = (4)²-5(4)-9 = -13 g(-3) = (-3)²-5(-3)-9 = 15 g(0) = 0²-5(0)-9 = -9 g(<math>a^4</math>) = (<math>a^4</math>)²-<math>5a^4</math>-9 = <math>a^8</math>-<math>5a^4</math>-9 g(x+h) = (x+h)²-5(x+h)-9 = x² + 2xh +h²-5x-5h-9 Wherever there is an x, you replace it by x + h! The range is {-13,-9,15,<math>a^8</math> -<math>5a^4</math>-9,x² +2xh +h²- 5x -5x -9}. '''Example 5''' Find :<math>\frac{f(x+h)-f(x)}{h}</math>. :<math>\frac{f(x+h)-f(x)}{h} = \frac{x+h} {x+h+5}-\frac{x}{x+5}/{h}</math> (Add the fractions. Two tricks: a/b-c/d=(ad-bc)/bd;(e/f)/h=e/fh.) :<math>\frac{f(x+h)-f(x)}{h} = \frac{(x+h)(x+5)-x(x+h+5)}{(x+h+5)(x+5)h}</math> (Multiply out the top; never multiply out the bottom.) :<math>\frac{f(x+h)-f(x)}{h} = \frac{5h}{(x+h+5)(x+5)h} = \frac{5}{(x+h+5)(x+5)}</math> (Cancel the h's.) This kind of problem occurs in almost every precalc book. What you should ask is why the heck it is here. I will tell you. This is very close to the topic you deal with in calculus. Here is a preview. We have learned that the slope of a straight line is always the same. However, if we draw any curve and draw all its tangent lines, the slope changes. We would like to study this and algebraize it. Given the point <math>P(x,f(x))\,</math> . A little bit away from P is point Q. Its x value is x + h, where x + h is an x value a little bit away from x. If the first coordinate is x + h, the second coordinate is f(x + h). Draw PQ, PR (horizontal line), and QR (vertical line). On any horizontal line all y values are the same. P and R have the same y values. Q and R have the same x values. Since Q and R have the same x values, the length of QR, which is the change in y or Δy, is <math>f(x + h) - f(x)\,</math>. Since P and R have the same y values, the length of PR, which is the change in x or Δx, is <math>(x + h) - x - = h\,</math>. The slope of the secant line l₂ joining the points P and Q is :<math>\frac{\Delta y}{\Delta x} = \frac{f(x+h)-f(x)}{h}</math> which is why we study this expression. But here's the conclusion. If we let h go to 0, graphically it means the point [x+h,f(x+h)] gets closer and closer to [x,f(x)]. If we do this process to the left of P as well as here to the right of P, and if they both approach the line ''l''_1, then what we have calculated is the slope of the tangent line l₁ at the point [x,f(x)]!!!!! You have taken your first step into calculus!!!!! 1-1 function. 1-1 is a property we need occasionally. '''DEFINITION''' If f(a) = f(b), then a = b. '''Examples 6 and 7''' f(x) = 2x is 1-1, but g(x) = x² is not 1-1. If f(a) = f(b), then 2a = 2b and a = b. If g(a) = g(b), then a² = b². But a could equal b or -b; therefore, not 1-1. ==One-to-One, Onto, One-to-One Correspondence, and Inverse Function== If every point in the range of a function is actually mapped to (that is, the range is the same as the image), the function is said to be ''onto''. A fancy term for this is that the function is ''surjective'' or is a ''surjection''. If no two points in the domain map to the same value, the function is said to be ''one-to-one''. A fancy term for this is that the function is ''injective'' or is an ''injection''. If a function is both one-to-one and onto, it is said to be a ''one-to-one correspondence''. A fancy term for this is that the function is ''bijective'' or is a ''bijection''. When a function is a one-to-one correspondence, something interesting happens. Refer back to the four fundamental principles given earlier. The third principle is that no two pairs have the same first element. But if the function is one-to-one, no two pairs have the same second element either. The fourth principle is that every element in the domain appears as the first item of one of the pairs. But if the function is onto, every element of the range appears as the second item of one of the pairs. This means that, if the function is both one-to-one and onto, we can swap the domain and range, and swap the first and second items of each pair, and still get a function. That function is the ''inverse'' of the original function. A bijection is invertible. The inverse of the function f is written f^-1. We have ::f ( f^-1 ( x ) ) = x for all x ::f^-1 ( f ( y ) ) = y for all y ==Image and Inverse Image== It is sometimes useful to speak of all of the function values for an entire set of points in the domain. Normally, when we say y=f(x), we mean that x is a specific element of the domain (for example, a specific number), and y is the single element that x maps to. {{clear}} [[Image:Image.jpg|right|thumb|250 px|The image, under a function, of an open interval.]] But sometimes we want to write something like Y=f(X), where X is a whole set. In this case, Y is the whole set of function values for all elements of X. :::<math>f(X) = \{\ y\ |\ y=f(x)\ \text{for}\ \text{some}\ x\ \in\ X\ \}</math> Y=f(X) is called the ''image'' of X. It is illustrated in the diagram to the right. The horizontal black line along the bottom edge depicts an open interval that we wish to find the image of. The vertical black line along the right edge depicts the image. The part of the function graph forming the image is shown in blue; the rest of the graph is in red. The grey lines are visual guides. {{clear}} [[Image:Invimage.jpg|right|thumb|250 px|The inverse image, under a function, of an open interval.]] Also, X is called the ''inverse image'' of Y, denoted X=f^-1(Y). That is, f^-1(Y) is the set of points that map into Y. :::<math>f^{-1}(Y)\ =\ \{\ x\ |\ f(x)\ \in\ Y\ \}</math> This is illustrated in the diagram to the right. The vertical black line along the right edge depicts an open interval that we wish to find the inverse image of. The horizontal black lines along the bottom edge depict the two open intervals comprising the inverse image. The part of the function graph forming the inverse image is shown in blue; the rest of the graph is in red. The grey lines are visual guides. ==References== <references/> [[Category:Mathematics]] [[Category:Mathematical functions]] [[ru:Функции]] hbqvbi7aisssm2zbh8vcjbk2z9d7iqc 0 112036 2414014 2413843 2022-08-13T00:02:07Z Rhythmicblueberry 2948078 Moved some terms from definitions to be added which had explanations into the main section. Refined a few definitions - aliveness, present, strong suit, throwing your hat over the wall wikitext text/x-wiki Many terms are used in Landmark Worldwide in special ways, and sometimes they are distinct from how people use these terms colloquially nowadays. For example, the term "enrollment" is used to mean "enrolling" others in a possibility, so that they are "moved, touched, and inspired," and does ''not'' refer to enrolling people in courses. "Registration" is as described below, and, in context, often refers to actually signing up for a course (the generic meaning in the training is the ''acceptance of an offered choice,'' but it is also used with the ordinary meaning, i.e, action to formally place one's name in a list of "registrants."). Every discipline has its own language, borrowing general terms and providing specific meanings. For example, in physics the words "force", "work", "power" are given specific meanings for the mathematical modeling to work consistently, so while "work" means force through a distance in physics, "work" means applying effort, either mental or physical, to everyone else. To a physicist, pressing as hard as you can against a wall and not moving it = no work; but to everyone else, it is a lot of possibly useless work, having exerted a lot of effort to no affect, other than to give your muscles some isometric exercise. So it is with Landmark, it borrows words from common language and gives them specific meanings, creating its own sublanguage, in order to communicate specific ideas in unusual ways. The idea is born out of the educational principle "you don't learn something until you have discovered it for yourself." The unusual usage forces fresh use of the mind to elicit the discovery of whatever is being presented. Please use this page to express definitions of these terms as used by Landmark. Discussion of these definitions should take place on the attached Talk page (the "Discuss" tab, usually above). If there are disagreements, we should attempt to find consensus on the Talk page. This resource is intended to explain how these words are actually used by leaders of seminars in Landmark, and by Landmark Forum graduates in the Landmark community, not to propose these definitions as the "correct" meanings of the words. Feel free to write definitions, and sign them with <nowiki><small>~~~</small></nowiki>. Feel free, as well, to write brief comments or alternative definitions. '''These definitions have not been approved by Landmark Worldwide.''' *{{anchor|Act}}'''Act.''' A command, a bold statement given by brain when one is held accountable for a failure (or perceived failure) in performance. It is often not said verbally but it is very loud inside the brain. It is what one says to people when they confront him and hold one accountable for something not done well or well enough. For example : DON'T TEACH ME!!, I KNOW IT ALL, GET LOST, I WILL SHOW YOU WHO I AM, etc. Now this way of being has impact of self and even though our ACT is not expressed verbally but it does show up in our way of being. It results in lack of power, well being and self expression. The experience of the one being his/her ACT and the people around both have experience which lacks JOY, Self Expression and happiness and there is no access to possibility or fruitful activity until it is acknowledged, resolved or dismissed. *{{anchor|Agreement/Alignment}}'''Agreement/Alignment''' For agreement is merely a condition of content in which everyone is going to same place. Alignment, on the other hand, is a context in which everyone is coming from the same source" <small>[[User:sercotec-lf|sercotec-lf]]</small> *{{anchor|Already/Always Listening}}'''Already always listening.'''™ Undistinguished pre-existing interpretations that shape, color and influence the way people experience their relationships with people, circumstances, and even themselves. Examples may include: rolling your eyes as you see a number or person you recognize calling your phone as you, before they have even spoken to you, decide you already know something about how that call will go.<small>[[User:grantlam|grantlam]]</small> :* That little voice in your head, the voice of your imagination, and the interpretations it is constantly making. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Advanced Course}}'''Advanced Course.''' The second course in the "Curriculum for Living." Whereas the Landmark Forum Deals with personal reality the Advanced Course deals with collective reality. *{{anchor|At Aliveness}}'''Aliveness.''' Occurrance when you get yourself in the game instead of spectate it and you are aware what you are doing at that moment. <small>[[User:sercotec-lf|sercotec-lf]]</small> The sense of vitality one experiences when in action, while performing an action when not impeded by the filters, patterns and limitations laid down in the past. *{{anchor|At effect}}'''At effect.''' Usage is "at the effect of [some circumstance]"; to be a victim of circumstances or dependent upon them for success. See also ''At cause.'' <small>[[User:Abd|Abd]]</small> *{{anchor|Authenticity}}'''Authenticity.''' When one is being consistent with how one portrays oneself with others and with oneself. When one is authoring one's life from a point of view of Self rather than reacting to the outside world or another's expectations or one's own familiar patterns. <small>[[User: grantlam|grantlam]]</small> *{{anchor|Breakthrough}}'''Breakthrough.''' Freeing yourself from some limitation that allows you to achieve immediate and permanent quantum leaps in performance and quality of life. Achieving unprecidented success in line with a stated aim that you had previously had trouble acheiving. <small>[[User: grantlam|grantlam]]</small> :* When "the light bulb clicks on in your head" and you "get it" and it causes a discrete change in behavior. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Breakdown}}'''Breakdown.''' A breakdown happens when some action in line with a stated possibility, intention or commitment is frustrated, stopped or thwarted. <small>[[User: grantlam|grantlam]]</small> :* When things don't go as expected or intended, or when you don't do as you said you would -- "not keeping your word" -- , also known as a loss of integrity, a loss of workability. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Complete}}'''Complete.''' When one is complete with any aspect of the past and therefore the past has no constraint on who one is being or how they are acting in the present. In communication, being complete is the experience of one being left with no lingering resentments, regrets or "unfinished business". One can declare something complete even when an aim has not been achieved if one wishes to move on. This is termed "being complete with being incomplete". <small>[[User: grantlam|grantlam]]</small> *{{anchor|Cost}}'''Cost.''' (as used in Rackets™). The undesirable impact of one’s reactive, self-serving, nasty ways of being and acting. See also ''Payoff.'' <small>[[User:Abd|Abd]]</small> edited by <small>[[User: grantlam|grantlam]]</small> :*The costs of ''rackets™'' are love/affinity, vitality/well-being, self-expression, and satisfaction/fulfillment, all of which fall under aliveness. <small>[[User:Shinigami Realm|Shinigami Realm]]</small> *{{anchor|Change}}'''Change.''' (versus transformation). Change begins with a something that is made different in distance (from here to there), time (from now to then) or form (for example, from a square to a circle). An aspect of the nature of change is that change causes the persistence of the something being changed. <small>[[User: grantlam|grantlam]]</small> :* Change is a gradual continual shift. Transformation is a discrete jump. A caterpillar transforms into a moth or butterfly, but the metamorphosis that happens in the cocoon is change. Improvement and evolution are in the world of change. It is a case of more, better, different. Transformation is about accepting something as it is - "no change" - such that it is fully appreciated for what it is, which causes disappearance. From this space of nothing, something new, unique and immediately relevant arises or can be created. Change = a+1 , Transformaton = a+0. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Choosing vs. Deciding}}'''Choosing vs. Deciding''' When presented with choices, an automatic reaction is to pick something over another thing - deciding. Deciding is related to other "*cide" words (suicide, insecticide, genocide), and is the result of applying reason to eliminate alternatives, effectively killing them off. Usually a single thing is left and that becomes the decision. Choosing is about making a choice purely for the sake of choosing, not applying reason, not applying logic, not removing or disqualifying the other choices. I have purposefully not quoted the Landmark definition of decision and choice as that is copywrited material by them. Everyone likes to use reason, but ultimately, at the bottom of every decision or even proofs, is either fundamental choice or reason: "I choose to believe ..." or "I choose to trust ..." adding "because" makes it a reason. By using reason, one then absolves oneself from responsibility for the choice, it becomes the fault of the reason or the reasoning process if it fails. Choice demands responsibility for making the choice. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{Anchor|Clearing}}'''Clearing''' The most common analogy is of a field, and removing the stones and stumps and whatever obstacles are there in the field, that interfere with the functioning of the field: whether to grow something, or to play a game, or something else. The abstraction in this case is a mental construct in which possibilities can be placed, created. The clearing is like a vacuum, and can draw things towards it. If the thing in the clearing is "I'm no good" then it draws things that supports that attitude. You are then a clearing for "I'm no good". If you want the possibility of contribution to the world to be in your clearing, to draw those flavors of possibilities and opportunities, then you would need to remove the "I'm no good" thing from your clearing. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Context}}'''Context.''' Context is your occurring world; the total of how the world around you, and the people and things in it (either in totality, or in a given situation), show up for you. Nearly all context in which humans live is created. As a "meaning-making machine", it forms the setting and the background of your ''story'' and you tend to take actions based upon it in response. And you take it for granted and don't realize it: the one thing your occurring world ''doesn't'' automatically occur for you as, is context. For example, for a fish, water is a major part of his context. A fish has no appreciation of water, it's just there, life consists of dealing with it all the time, he 'swims in it'. No other fish has ever been out of water for any length of time and come back to tell him what it's like, so the fish doesn't know anything but water, and nothing else is possible to him. (The difference is, the fish's context of water is beneficial to him, and he can't overcome it and survive. You, however, might "swim in" a context that ''isn't'' altogether beneficial to you, and that you ''can'' overcome. By contrast, ''responsibility'' is an ''empowering'' context.) When your life sucks, when you're in a negative or disempowering context; the way to break out of it, to overcome the negative or disempowering context, is to distinguish something (see ''Distinguish'', ''Distinction''). Then you can see your disempowering ''story'' as a story, and take new action in alignment with reality; or take on one or more new ways of being that might work better for you. <small>[[User:makeitrain27028|MakeItRain]]</small> *{{anchor|Curriculum for Living}}'''Curriculum for Living™''' The basic Landmark curriculum, which includes The Landmark Forum®, The Advanced Course®, The Self Expression and Leadership Program, and The Landmark Forum In Action Series. Since the courses have gone online in 2020, the Curriculum has the Introduction Leader's Programme instead of the Self Expression and Leadership Programme and there is no mention of the Landmark in Action Seminar Series. *{{anchor|Disappear}}'''Disappear''' To "disappear something" is to eliminate or evaporate it, such as to disappear a complaint. This is done by fully acknowledging it for what it is and what it isn't such that it no longer has any hold over you, and no longer "sits in your space" or clearing. See Change vs Transformation. <small>[[User:JF|JF]], edited by [[User:Abd|Abd]] ([[User talk:Abd|discuss]] • [[Special:Contributions/Abd|contribs]])</small> *{{anchor|Distinction}}'''Distinction.''' A distinction is a linguistic phenomenon that brings something into being as a presence, for which previously there was no presence. It brings something into contrast so it stands out where previously it did not show up as a thing. <small>[[User: grantlam|grantlam]]</small> :* The idea of a distinction comes from Taoism, when you name something as beautiful, not beautiful comes into existence as well. It also comes from sublanguages created to facilitate an area of thought or information -- the example of physics used above. A distinction is simply a term, a word, used to name something to facilitate the abstraction, discussion and/or use of that thing. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Distinguish}}'''Distinguish.''' To take something from an undifferentiated background and bring it to the foreground. <small>[[User:Shinigami Realm|Shinigami Realm]]</small> *{{anchor|Effect}}'''Effect.''' See ''At effect.'' *{{anchor|Empty}}'''Empty.''' No content, not real, made up, no substance. Generally used in conjunction with "meaningless" as in "empty and meaningless" see "meaningless" below. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Enrollment}}'''Enrollment.''' A kind of sharing that causes a new realm of possibility to be present for another such that they are touched moved and inspired by that new possibility. This is not to be confused with Registration. <small>[[User: grantlam|grantlam]]</small> *{{anchor|Force}}'''Force.''' (versus power. Force is not a distinction recognized by Landmark. Personally, I feel that 'force' should be a distinction -- force as distinct from 'power', since within the Landmark technology, the two terms are so often used together, and so often contrasted against one another -- so I'll attempt to generate one for you here that will work for you.) Access to the distinction between force vs. power, lies in the outcome, the result. Power produces outcomes that will fall into place without a whole lot of resistance, and that once in place will stay in place indefinitely. Force can produce outcomes, but force nearly always meets with resistance. Force frequently produces outcomes other than what the person applying the force wants, or had in mind. Force produces unintended consequences. No one likes being forced, after all, and most anyone will seek ways to thwart whatever or whoever is trying to force something on them. And when force produces an outcome at all, that outcome will stay in place only for as long as the force can continue to be applied effectively. Once the force goes away, or is removed, or is met with an opposing force; once someone who is unhappy with the outcome produced by force comes up with a way to get around the force, or force back, or to evade the punishment that it threatens, the outcome produced by force is going to unravel. Power is, by its nature, successful. Force, by its nature, isn't successful, and certainly isn't powerful. Access to power lies in force-free communication. <small>[[User:makeitrain27028|MakeItRain]]</small> *{{anchor|Forum}}'''The Landmark Forum.''' An accelerated learning experience, set up as a guided dialog between the instructor and participants designed to bring about a transformational shift in the participants' effectiveness and quality of life in three and a half days. The first course in the "Curriculum for Living," The Landmark Forum® is the entry point for all Landmark programs. <small>[[User: grantlam|grantlam]]</small> *{{anchor|Graduate}}'''Graduate.''' A person who has completed The Landmark Forum. edited by <small>[[User: grantlam|grantlam]]</small> *'''I.''' The distinction of the structure and patterns people tend to identify with, and form identity from, as being a collection of fixed characteristics, attributes, hijacked survival responses and experiences from the past. <small>[[User:Shinigami Realm|Shinigami Realm]]</small> :*A pattern of patterns of neurons firing, see ''Identity.'' <small>[[User:Abd|Abd]]</small> *{{anchor|Identity}}'''Identity.''' A story that we invented about ourselves. The process of inventing an identity began in childhood, as we gradually adopted ways of being and acting to deal successfully with things that didn't quite go the way we thought they should. <small>[[User:Abd|Abd]]</small> *{{anchor|Informative learning}}'''Informative learning.''' Learning that increases what people know and adds to their skills by bringing new knowledge to an existing worldview and frame of reference. Compare to ''transformative learning.'' <small>[[User:Shinigami Realm|Shinigami Realm]]</small> *{{anchor|Integrity}}'''Integrity.''' Integrity is a state or condition of being whole, perfect, complete and unimpaired, in perfect condition. For a person, integrity is a matter of a person’s word. The extent to which who you are reflects the person you intend to be. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:02, 23 September 2016 (UTC) :* Integrity is well defined in a dictionary and covers all usage in Landmark. It is presented, though, from a perspective of workability. The more workable, the more integrity, the less workable, there is a loss of integrity. Keeping ones word is associated with integrity -- agreeing with common usage -- but in Landmark, it is a progression. Not keeping your word, means you were inauthentic about your word. Inauthenticity leads to unreliability, which reduces workability, and thus a loss of integrity. If you say you will be at a meeting at 5pm and show up at 5:10pm, there is inauthenticity, and there is the loss of 10 minutes of time, reducing the workability of the meeting, which may have to still end on time, so there is less time for discussion, information sharing, etc. which can lead to incompleteness, which reduces workability. Thus a lack of integrity, a loss of integrity, or simply, no integrity. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Life}}'''Life,''' as in "yourself and your life." Our entire set of relationships with people. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:04, 23 September 2016 (UTC) *{{Anchor|Listening}}'''Listening''' In Landmark Education, "Listening" does include the action of actually listening to another person in the common sense, but also includes a state of being. In this regard, the qualifying statements are similar to "... in your listening". This state of being is recognized as providing a coloration to your listening to what others are saying, and to what is happening around you, even if no sound is hitting your ears. It is the application of interpretation, and the recognition that we are always applying some sort of interpretation to our sensory input. By recognizing that we are applying color, and the color that is being applied, we can then choose that coloration. The state of being is referred to as "your clearing", and that clearing provides the coloration, the interpretation, and the responses produced. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Meaningless}}'''Meaningless.''' The absence of inherent meaning. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:04, 23 September 2016 (UTC) :* Used in conjunction with "empty" as in "empty and meaningless". This sentiment comes from Ecclesiastes. Meaning is the association of things with other things. This is an action of interpretation, of creating "story". Since it is made up, it is not real, and therefore empty. People tend to use "meaning" to ascribe substance and value to something. But since the meaning is made up, empty, it is really meaningless, without substance, and thus subject to change, alteration, transformation, or disappearance. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Occur}}'''Occur''' Used in the plural form, as in "how it occurs ...", in an active form "occurring" and in the past tense "how it occurred ..." . The interpretation of something. Occurring applies story, reason, to what happened, or to how you think about something. Occurring is a subconscious summarization and associative process that hits the conscious mind as real, as truth. It is difficult to recognize this without training. Someone yelling at you could occur as they being angry; or you thinking they think you are deaf, or stupid; or as an urgent notification of something you need to pay attention to; or something else. Thus when trying to describe what happened, you may include that interpretation unknowingly, when it is really how it occurred to you. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Payoff}}'''Payoff.''' A payoff is something one gets out of certain ways of being and acting that is not immediately obvious. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:04, 23 September 2016 (UTC) *{{anchor|Possibility}}'''Possibility.''' A phenomenon in language that creates a new future now. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:04, 23 September 2016 (UTC) *{{anchor|Power}}'''Power.''' The rate at which an intention is turned into a result [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{Anchor}}'''Present.''' Being Present is to be truly listening with a quiet mind. You are not thinking of what you need to do next or what you are going to say next. Instead, you are fully present in the conversation. You are hearing every word. *{{anchor|Racket}}'''Racket.'''™ A persistent complaint combined with a fixed way of being. Rackets are maintained because of payoffs (see ''payoff'') and persist until dropping the racket (and thus its associated cost) is chosen. <small>[[User:Abd|Abd]]</small> *{{anchor|Reality}}'''Reality.''' That which is real either independently of language (e.g., a car) and that which is real only in language (e.g., a concept). [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Reason}}'''Reason.''' An excuse we invent to justify choices we make. That would be [[w:Ambrose Bierce]]'s definition. When choices are made according to "reasons," they are distinguished as the "machine" operating, based on assumptions about truth and reality. Genuine choice operates on another level. Reasoning is not denied, but ''distinguished'' as rooted in our ''stories'' about reality. NOTE: This is not a Landmark term. Just the generic meaning of the word is used in Landmark programs.[[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Reasonable}}'''Reasonable.''' To justify acting or not acting based on reasons and justifications. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Registration}}'''Registration.''' See also ''Enrollment.'' Some action that registers a commitment to the future, for example registering for a gym membership. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Resentment}}'''Resentment.''' A poison people swallow hoping it will kill the other person. NOTE: This is not a Landmark term. Just the generic meaning of the word is used in Landmark programs. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Responsibility}}'''Responsibility.''' ''“Responsibility begins with the willingness to take the stand that one is cause in the matter of one’s life. It is a declaration not an assertion, that is, it is a context from which one chooses to live. Responsibility is not burden, fault, praise, blame, credit, shame or guilt. In responsibility, there is no evaluation of good or bad, right or wrong. There is simply what’s so, and the stand you choose to take on what’s so. Being responsible starts with the willingness to deal with a situation from the view of life that you are the generator of what you do, what you have and what you are. That is not the truth. It is a place to stand. No one can make you responsible, nor can you impose responsibility on another. It is a grace you give yourself – an empowering context that leaves you with a say in the matter of life.”'' (Werner Erhard) <small>[[User:makeitrain27028|MakeItRain]]</small> *{{anchor|Self-Expression and Leadership Program}}'''Self-Expression and Leadership Program.''' The final course in the original Curriculum for Living®., this program expands one’s natural capacity for providing leadership and making a difference as a natural self-expression. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Speaking into the listening}}'''Speaking into the listening.''' Effectively communicating to another such that the communication is heard in the way in which the speaker intended. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Stinginess}}'''Stinginess.''' Deliberately holding oneself and one’s contribution ‘close to the vest’ and without generosity. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Story}}'''Story.''' A "story" is an account or interpretation of past events often mistakenly taken for what actually happened. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Strong suit}}'''Strong suit.''' A way of being and acting one relies on to produce results and make it in life. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) Also called a "winning formula" or "winning way." --[[User:Abd|Abd]] ([[User talk:Abd|discuss]] • [[Special:Contributions/Abd|contribs]]) 22:10, 17 October 2017 (UTC) It is developed and locked in place during stressful periods of life when the young person experiences a failure in being - where their natural way of being doesn't appear sufficient to deal with the situation that occurs, and one thinks, "I need to be ...trait.... like ...admired person". *{{anchor|Superstition}}'''Superstition.''' The system of ideas, beliefs, social and cultural assumptions, and taken-for-granted conclusions, etc., through which an individual interprets and interacts with the world, other people, and himself or herself. <small>[[User:Shinigami Realm|Shinigami Realm]]</small> NOTE: This is not a Landmark term. Just the generic meaning of the word is used in Landmark programs. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) In Landmark it is taken a step further, to challenge the fixed impression of identity and reality by examining the words "I" and "is". *'''{{Anchor}}Throwing your hat over the wall'''. Committing to an outcome without knowing how it can be accomplished, comes from a story told by Irish writer Frank O’Connor of two boys standing beside a tall orchard wall, wanting to pick apples. They didn't know know how they'd get over the wall but they did know they'd get in trouble if they came home without their hats so they threw them over the wall and climbed after them. *{{anchor|Transformation}}'''Transformation.''' The invention of a new realm of possibility for yourself and your life. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) :* The invention of the realm is a necessary condition, but not sufficient for transformation. Without resultant new actions in alignment with the possibilities populating the realm, the invention is just a mental exercise. <small>[[User:AnyTDorH|AnyTDorH]]</small> :* Transformation is used in the sense of a new state of being where the experience is generated from the Self, as a Self-expression instead of from the identity, from the fixed, repetitive patterns of behaviour. *{{anchor|Transformative learning}}'''Transformative learning.''' Transformative learning, gives people an awareness of the basic structures in which one knows, thinks, and acts in the world. From that awareness comes a fundamental shift that leaves people more fully in accord with their own possibilities and those of others. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) :* Transformative learning is contrasted with Informational Learning. Informational learning increases knowledge and ability. Transformative learning results in new perspectives and new abilities (and sometimes disabilities). The common example is of learning to ride a bicycle. Very little information is provided, like "pedal". Suddenly the learner gets balance and is able to ride the bike without help. They have discovered it for themselves, and may never lose the ability to ride a bike. The experience, the learning, transforms the person, their perspective and their abilities. Before they couldn't, now they can. And, a whole new world or realm of possibilities is opened up. <small>[[User:AnyTDorH|AnyTDorH]]</small> * {{Anchor}}'''Trump Card.''' The card you pull out to deflect a challenge to your Act. It appears as an unspoken taunt, challenge or gesture such as "Get lost!" or "Why should I? You're a loser anyway". It is so consistant it is extremely predicable when someone is being their Act and don't realise it, they will simply act out this way every time. *{{anchor|Unreasonable}}'''Unreasonable.''' Not to be mistaken for irrational; it is going beyond one’s reasons, justifications and considerations to act on something one is committed to. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Unreasonable Request}}'''Unreasonable Request.''' A request that requires one to go beyond one’s reasons, justifications and considerations to act on something one is committed to. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Vicious circle}}'''Vicious circle.'''™ The human tendency to collapse what happened with the story we tell about what happened. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) :* The story creates a clearing, a listening, for that which supports the story, resulting in more occurrences of things that further support the story, forming a self supporting vicious circle. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|What happened}}'''What happened.''' Consensual reality, "objective," aside from judgment, blame, right/wrong, good/bad, and other forms of "meaning." What happens occurs to us as it is analyzed by the Already Always Listening to be good/bad, etc. If my ex-wife told me she had a problem with what I've done, that's what happened. If I say that she was unreasonable, that's my story about it, not what happened. See also ''Story.'' <small>--[[User:Abd|Abd]]</small> NOTE: This is not a Landmark term. Just the generic meaning of the word is used in Landmark programs. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{Anchor}}'''Winning Formula'''. See Strong Suit. The Winning Forumula was a later term for this distinction. Terms with "™" are known to be trademarked by Landmark Education. ==Definitions to be added== *Alacrity *At choice (vs. at effect) *At stake *Being *Choice *Commitment *Communication *Competencies *Complaint *Complete *Conspiracy *Dimensions *Fixed way of being *Generate is to choose to create thoughts of possibility and making it happen. Also, making a list of effective actions to move it forward. *Gossip *Got it. means you understand what the other person is saying. *Ideals *Incomplete *Language *Levels of Self *Looking good *No agreement *More, better, different *On the court (or in the stands)- playing the game of life by taking actions and being in the game, not watching from the bleachers. *Principles *Presence of a person *Realm of survival/Realm of enrollment *Sharing *Significance *Source *Stand *Standards *Technology *Touch, move, or inspire (define the whole phrase as an indicator of enrollment + define each term) *Transform (versus change) *Upset *Values *Velocity *Vitality *What's so ==External Links== *[http://landmarkforum.tribe.net/thread/897acaa1-f09d-412d-aee0-2ff019c2dbd7 landmarkforum.tribe.net] post on "The language of Landmark." *[http://www.whatsthedealaboutlandmark.com/forum_05.htm whatsthedealaboutLandmark.com] post on "What is Landmark jargon?" *[https://www.academia.edu/3789932/Religiosity_Rejected_Exploring_the_Religio-Spiritual_Dimensions_of_Landmark_Education International Journal For the Study of New Religions] "Religiosity Rejected:Exploring the Religio-Spiritual Dimensions of Landmark Education," Renee Lockwood, 2011, pp. 225–254, see page 226-227 for a mention of the language of Landmark. [[Category:Landmark Forum|{{SUBPAGENAME}}]] clmbeh226s1gxxyz405f61j782ec5qq 2414015 2414014 2022-08-13T00:07:29Z Rhythmicblueberry 2948078 Added Self to list of future definitions wikitext text/x-wiki Many terms are used in Landmark Worldwide in special ways, and sometimes they are distinct from how people use these terms colloquially nowadays. For example, the term "enrollment" is used to mean "enrolling" others in a possibility, so that they are "moved, touched, and inspired," and does ''not'' refer to enrolling people in courses. "Registration" is as described below, and, in context, often refers to actually signing up for a course (the generic meaning in the training is the ''acceptance of an offered choice,'' but it is also used with the ordinary meaning, i.e, action to formally place one's name in a list of "registrants."). Every discipline has its own language, borrowing general terms and providing specific meanings. For example, in physics the words "force", "work", "power" are given specific meanings for the mathematical modeling to work consistently, so while "work" means force through a distance in physics, "work" means applying effort, either mental or physical, to everyone else. To a physicist, pressing as hard as you can against a wall and not moving it = no work; but to everyone else, it is a lot of possibly useless work, having exerted a lot of effort to no affect, other than to give your muscles some isometric exercise. So it is with Landmark, it borrows words from common language and gives them specific meanings, creating its own sublanguage, in order to communicate specific ideas in unusual ways. The idea is born out of the educational principle "you don't learn something until you have discovered it for yourself." The unusual usage forces fresh use of the mind to elicit the discovery of whatever is being presented. Please use this page to express definitions of these terms as used by Landmark. Discussion of these definitions should take place on the attached Talk page (the "Discuss" tab, usually above). If there are disagreements, we should attempt to find consensus on the Talk page. This resource is intended to explain how these words are actually used by leaders of seminars in Landmark, and by Landmark Forum graduates in the Landmark community, not to propose these definitions as the "correct" meanings of the words. Feel free to write definitions, and sign them with <nowiki><small>~~~</small></nowiki>. Feel free, as well, to write brief comments or alternative definitions. '''These definitions have not been approved by Landmark Worldwide.''' *{{anchor|Act}}'''Act.''' A command, a bold statement given by brain when one is held accountable for a failure (or perceived failure) in performance. It is often not said verbally but it is very loud inside the brain. It is what one says to people when they confront him and hold one accountable for something not done well or well enough. For example : DON'T TEACH ME!!, I KNOW IT ALL, GET LOST, I WILL SHOW YOU WHO I AM, etc. Now this way of being has impact of self and even though our ACT is not expressed verbally but it does show up in our way of being. It results in lack of power, well being and self expression. The experience of the one being his/her ACT and the people around both have experience which lacks JOY, Self Expression and happiness and there is no access to possibility or fruitful activity until it is acknowledged, resolved or dismissed. *{{anchor|Agreement/Alignment}}'''Agreement/Alignment''' For agreement is merely a condition of content in which everyone is going to same place. Alignment, on the other hand, is a context in which everyone is coming from the same source" <small>[[User:sercotec-lf|sercotec-lf]]</small> *{{anchor|Already/Always Listening}}'''Already always listening.'''™ Undistinguished pre-existing interpretations that shape, color and influence the way people experience their relationships with people, circumstances, and even themselves. Examples may include: rolling your eyes as you see a number or person you recognize calling your phone as you, before they have even spoken to you, decide you already know something about how that call will go.<small>[[User:grantlam|grantlam]]</small> :* That little voice in your head, the voice of your imagination, and the interpretations it is constantly making. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Advanced Course}}'''Advanced Course.''' The second course in the "Curriculum for Living." Whereas the Landmark Forum Deals with personal reality the Advanced Course deals with collective reality. *{{anchor|At Aliveness}}'''Aliveness.''' Occurrance when you get yourself in the game instead of spectate it and you are aware what you are doing at that moment. <small>[[User:sercotec-lf|sercotec-lf]]</small> The sense of vitality one experiences when in action, while performing an action when not impeded by the filters, patterns and limitations laid down in the past. *{{anchor|At effect}}'''At effect.''' Usage is "at the effect of [some circumstance]"; to be a victim of circumstances or dependent upon them for success. See also ''At cause.'' <small>[[User:Abd|Abd]]</small> *{{anchor|Authenticity}}'''Authenticity.''' When one is being consistent with how one portrays oneself with others and with oneself. When one is authoring one's life from a point of view of Self rather than reacting to the outside world or another's expectations or one's own familiar patterns. <small>[[User: grantlam|grantlam]]</small> *{{anchor|Breakthrough}}'''Breakthrough.''' Freeing yourself from some limitation that allows you to achieve immediate and permanent quantum leaps in performance and quality of life. Achieving unprecidented success in line with a stated aim that you had previously had trouble acheiving. <small>[[User: grantlam|grantlam]]</small> :* When "the light bulb clicks on in your head" and you "get it" and it causes a discrete change in behavior. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Breakdown}}'''Breakdown.''' A breakdown happens when some action in line with a stated possibility, intention or commitment is frustrated, stopped or thwarted. <small>[[User: grantlam|grantlam]]</small> :* When things don't go as expected or intended, or when you don't do as you said you would -- "not keeping your word" -- , also known as a loss of integrity, a loss of workability. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Complete}}'''Complete.''' When one is complete with any aspect of the past and therefore the past has no constraint on who one is being or how they are acting in the present. In communication, being complete is the experience of one being left with no lingering resentments, regrets or "unfinished business". One can declare something complete even when an aim has not been achieved if one wishes to move on. This is termed "being complete with being incomplete". <small>[[User: grantlam|grantlam]]</small> *{{anchor|Cost}}'''Cost.''' (as used in Rackets™). The undesirable impact of one’s reactive, self-serving, nasty ways of being and acting. See also ''Payoff.'' <small>[[User:Abd|Abd]]</small> edited by <small>[[User: grantlam|grantlam]]</small> :*The costs of ''rackets™'' are love/affinity, vitality/well-being, self-expression, and satisfaction/fulfillment, all of which fall under aliveness. <small>[[User:Shinigami Realm|Shinigami Realm]]</small> *{{anchor|Change}}'''Change.''' (versus transformation). Change begins with a something that is made different in distance (from here to there), time (from now to then) or form (for example, from a square to a circle). An aspect of the nature of change is that change causes the persistence of the something being changed. <small>[[User: grantlam|grantlam]]</small> :* Change is a gradual continual shift. Transformation is a discrete jump. A caterpillar transforms into a moth or butterfly, but the metamorphosis that happens in the cocoon is change. Improvement and evolution are in the world of change. It is a case of more, better, different. Transformation is about accepting something as it is - "no change" - such that it is fully appreciated for what it is, which causes disappearance. From this space of nothing, something new, unique and immediately relevant arises or can be created. Change = a+1 , Transformaton = a+0. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Choosing vs. Deciding}}'''Choosing vs. Deciding''' When presented with choices, an automatic reaction is to pick something over another thing - deciding. Deciding is related to other "*cide" words (suicide, insecticide, genocide), and is the result of applying reason to eliminate alternatives, effectively killing them off. Usually a single thing is left and that becomes the decision. Choosing is about making a choice purely for the sake of choosing, not applying reason, not applying logic, not removing or disqualifying the other choices. I have purposefully not quoted the Landmark definition of decision and choice as that is copywrited material by them. Everyone likes to use reason, but ultimately, at the bottom of every decision or even proofs, is either fundamental choice or reason: "I choose to believe ..." or "I choose to trust ..." adding "because" makes it a reason. By using reason, one then absolves oneself from responsibility for the choice, it becomes the fault of the reason or the reasoning process if it fails. Choice demands responsibility for making the choice. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{Anchor|Clearing}}'''Clearing''' The most common analogy is of a field, and removing the stones and stumps and whatever obstacles are there in the field, that interfere with the functioning of the field: whether to grow something, or to play a game, or something else. The abstraction in this case is a mental construct in which possibilities can be placed, created. The clearing is like a vacuum, and can draw things towards it. If the thing in the clearing is "I'm no good" then it draws things that supports that attitude. You are then a clearing for "I'm no good". If you want the possibility of contribution to the world to be in your clearing, to draw those flavors of possibilities and opportunities, then you would need to remove the "I'm no good" thing from your clearing. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Context}}'''Context.''' Context is your occurring world; the total of how the world around you, and the people and things in it (either in totality, or in a given situation), show up for you. Nearly all context in which humans live is created. As a "meaning-making machine", it forms the setting and the background of your ''story'' and you tend to take actions based upon it in response. And you take it for granted and don't realize it: the one thing your occurring world ''doesn't'' automatically occur for you as, is context. For example, for a fish, water is a major part of his context. A fish has no appreciation of water, it's just there, life consists of dealing with it all the time, he 'swims in it'. No other fish has ever been out of water for any length of time and come back to tell him what it's like, so the fish doesn't know anything but water, and nothing else is possible to him. (The difference is, the fish's context of water is beneficial to him, and he can't overcome it and survive. You, however, might "swim in" a context that ''isn't'' altogether beneficial to you, and that you ''can'' overcome. By contrast, ''responsibility'' is an ''empowering'' context.) When your life sucks, when you're in a negative or disempowering context; the way to break out of it, to overcome the negative or disempowering context, is to distinguish something (see ''Distinguish'', ''Distinction''). Then you can see your disempowering ''story'' as a story, and take new action in alignment with reality; or take on one or more new ways of being that might work better for you. <small>[[User:makeitrain27028|MakeItRain]]</small> *{{anchor|Curriculum for Living}}'''Curriculum for Living™''' The basic Landmark curriculum, which includes The Landmark Forum®, The Advanced Course®, The Self Expression and Leadership Program, and The Landmark Forum In Action Series. Since the courses have gone online in 2020, the Curriculum has the Introduction Leader's Programme instead of the Self Expression and Leadership Programme and there is no mention of the Landmark in Action Seminar Series. *{{anchor|Disappear}}'''Disappear''' To "disappear something" is to eliminate or evaporate it, such as to disappear a complaint. This is done by fully acknowledging it for what it is and what it isn't such that it no longer has any hold over you, and no longer "sits in your space" or clearing. See Change vs Transformation. <small>[[User:JF|JF]], edited by [[User:Abd|Abd]] ([[User talk:Abd|discuss]] • [[Special:Contributions/Abd|contribs]])</small> *{{anchor|Distinction}}'''Distinction.''' A distinction is a linguistic phenomenon that brings something into being as a presence, for which previously there was no presence. It brings something into contrast so it stands out where previously it did not show up as a thing. <small>[[User: grantlam|grantlam]]</small> :* The idea of a distinction comes from Taoism, when you name something as beautiful, not beautiful comes into existence as well. It also comes from sublanguages created to facilitate an area of thought or information -- the example of physics used above. A distinction is simply a term, a word, used to name something to facilitate the abstraction, discussion and/or use of that thing. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Distinguish}}'''Distinguish.''' To take something from an undifferentiated background and bring it to the foreground. <small>[[User:Shinigami Realm|Shinigami Realm]]</small> *{{anchor|Effect}}'''Effect.''' See ''At effect.'' *{{anchor|Empty}}'''Empty.''' No content, not real, made up, no substance. Generally used in conjunction with "meaningless" as in "empty and meaningless" see "meaningless" below. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Enrollment}}'''Enrollment.''' A kind of sharing that causes a new realm of possibility to be present for another such that they are touched moved and inspired by that new possibility. This is not to be confused with Registration. <small>[[User: grantlam|grantlam]]</small> *{{anchor|Force}}'''Force.''' (versus power. Force is not a distinction recognized by Landmark. Personally, I feel that 'force' should be a distinction -- force as distinct from 'power', since within the Landmark technology, the two terms are so often used together, and so often contrasted against one another -- so I'll attempt to generate one for you here that will work for you.) Access to the distinction between force vs. power, lies in the outcome, the result. Power produces outcomes that will fall into place without a whole lot of resistance, and that once in place will stay in place indefinitely. Force can produce outcomes, but force nearly always meets with resistance. Force frequently produces outcomes other than what the person applying the force wants, or had in mind. Force produces unintended consequences. No one likes being forced, after all, and most anyone will seek ways to thwart whatever or whoever is trying to force something on them. And when force produces an outcome at all, that outcome will stay in place only for as long as the force can continue to be applied effectively. Once the force goes away, or is removed, or is met with an opposing force; once someone who is unhappy with the outcome produced by force comes up with a way to get around the force, or force back, or to evade the punishment that it threatens, the outcome produced by force is going to unravel. Power is, by its nature, successful. Force, by its nature, isn't successful, and certainly isn't powerful. Access to power lies in force-free communication. <small>[[User:makeitrain27028|MakeItRain]]</small> *{{anchor|Forum}}'''The Landmark Forum.''' An accelerated learning experience, set up as a guided dialog between the instructor and participants designed to bring about a transformational shift in the participants' effectiveness and quality of life in three and a half days. The first course in the "Curriculum for Living," The Landmark Forum® is the entry point for all Landmark programs. <small>[[User: grantlam|grantlam]]</small> *{{anchor|Graduate}}'''Graduate.''' A person who has completed The Landmark Forum. edited by <small>[[User: grantlam|grantlam]]</small> *'''I.''' The distinction of the structure and patterns people tend to identify with, and form identity from, as being a collection of fixed characteristics, attributes, hijacked survival responses and experiences from the past. <small>[[User:Shinigami Realm|Shinigami Realm]]</small> :*A pattern of patterns of neurons firing, see ''Identity.'' <small>[[User:Abd|Abd]]</small> *{{anchor|Identity}}'''Identity.''' A story that we invented about ourselves. The process of inventing an identity began in childhood, as we gradually adopted ways of being and acting to deal successfully with things that didn't quite go the way we thought they should. <small>[[User:Abd|Abd]]</small> *{{anchor|Informative learning}}'''Informative learning.''' Learning that increases what people know and adds to their skills by bringing new knowledge to an existing worldview and frame of reference. Compare to ''transformative learning.'' <small>[[User:Shinigami Realm|Shinigami Realm]]</small> *{{anchor|Integrity}}'''Integrity.''' Integrity is a state or condition of being whole, perfect, complete and unimpaired, in perfect condition. For a person, integrity is a matter of a person’s word. The extent to which who you are reflects the person you intend to be. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:02, 23 September 2016 (UTC) :* Integrity is well defined in a dictionary and covers all usage in Landmark. It is presented, though, from a perspective of workability. The more workable, the more integrity, the less workable, there is a loss of integrity. Keeping ones word is associated with integrity -- agreeing with common usage -- but in Landmark, it is a progression. Not keeping your word, means you were inauthentic about your word. Inauthenticity leads to unreliability, which reduces workability, and thus a loss of integrity. If you say you will be at a meeting at 5pm and show up at 5:10pm, there is inauthenticity, and there is the loss of 10 minutes of time, reducing the workability of the meeting, which may have to still end on time, so there is less time for discussion, information sharing, etc. which can lead to incompleteness, which reduces workability. Thus a lack of integrity, a loss of integrity, or simply, no integrity. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Life}}'''Life,''' as in "yourself and your life." Our entire set of relationships with people. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:04, 23 September 2016 (UTC) *{{Anchor|Listening}}'''Listening''' In Landmark Education, "Listening" does include the action of actually listening to another person in the common sense, but also includes a state of being. In this regard, the qualifying statements are similar to "... in your listening". This state of being is recognized as providing a coloration to your listening to what others are saying, and to what is happening around you, even if no sound is hitting your ears. It is the application of interpretation, and the recognition that we are always applying some sort of interpretation to our sensory input. By recognizing that we are applying color, and the color that is being applied, we can then choose that coloration. The state of being is referred to as "your clearing", and that clearing provides the coloration, the interpretation, and the responses produced. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Meaningless}}'''Meaningless.''' The absence of inherent meaning. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:04, 23 September 2016 (UTC) :* Used in conjunction with "empty" as in "empty and meaningless". This sentiment comes from Ecclesiastes. Meaning is the association of things with other things. This is an action of interpretation, of creating "story". Since it is made up, it is not real, and therefore empty. People tend to use "meaning" to ascribe substance and value to something. But since the meaning is made up, empty, it is really meaningless, without substance, and thus subject to change, alteration, transformation, or disappearance. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Occur}}'''Occur''' Used in the plural form, as in "how it occurs ...", in an active form "occurring" and in the past tense "how it occurred ..." . The interpretation of something. Occurring applies story, reason, to what happened, or to how you think about something. Occurring is a subconscious summarization and associative process that hits the conscious mind as real, as truth. It is difficult to recognize this without training. Someone yelling at you could occur as they being angry; or you thinking they think you are deaf, or stupid; or as an urgent notification of something you need to pay attention to; or something else. Thus when trying to describe what happened, you may include that interpretation unknowingly, when it is really how it occurred to you. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|Payoff}}'''Payoff.''' A payoff is something one gets out of certain ways of being and acting that is not immediately obvious. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:04, 23 September 2016 (UTC) *{{anchor|Possibility}}'''Possibility.''' A phenomenon in language that creates a new future now. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:04, 23 September 2016 (UTC) *{{anchor|Power}}'''Power.''' The rate at which an intention is turned into a result [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{Anchor}}'''Present.''' Being Present is to be truly listening with a quiet mind. You are not thinking of what you need to do next or what you are going to say next. Instead, you are fully present in the conversation. You are hearing every word. *{{anchor|Racket}}'''Racket.'''™ A persistent complaint combined with a fixed way of being. Rackets are maintained because of payoffs (see ''payoff'') and persist until dropping the racket (and thus its associated cost) is chosen. <small>[[User:Abd|Abd]]</small> *{{anchor|Reality}}'''Reality.''' That which is real either independently of language (e.g., a car) and that which is real only in language (e.g., a concept). [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Reason}}'''Reason.''' An excuse we invent to justify choices we make. That would be [[w:Ambrose Bierce]]'s definition. When choices are made according to "reasons," they are distinguished as the "machine" operating, based on assumptions about truth and reality. Genuine choice operates on another level. Reasoning is not denied, but ''distinguished'' as rooted in our ''stories'' about reality. NOTE: This is not a Landmark term. Just the generic meaning of the word is used in Landmark programs.[[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Reasonable}}'''Reasonable.''' To justify acting or not acting based on reasons and justifications. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Registration}}'''Registration.''' See also ''Enrollment.'' Some action that registers a commitment to the future, for example registering for a gym membership. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Resentment}}'''Resentment.''' A poison people swallow hoping it will kill the other person. NOTE: This is not a Landmark term. Just the generic meaning of the word is used in Landmark programs. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Responsibility}}'''Responsibility.''' ''“Responsibility begins with the willingness to take the stand that one is cause in the matter of one’s life. It is a declaration not an assertion, that is, it is a context from which one chooses to live. Responsibility is not burden, fault, praise, blame, credit, shame or guilt. In responsibility, there is no evaluation of good or bad, right or wrong. There is simply what’s so, and the stand you choose to take on what’s so. Being responsible starts with the willingness to deal with a situation from the view of life that you are the generator of what you do, what you have and what you are. That is not the truth. It is a place to stand. No one can make you responsible, nor can you impose responsibility on another. It is a grace you give yourself – an empowering context that leaves you with a say in the matter of life.”'' (Werner Erhard) <small>[[User:makeitrain27028|MakeItRain]]</small> *{{anchor|Self-Expression and Leadership Program}}'''Self-Expression and Leadership Program.''' The final course in the original Curriculum for Living®., this program expands one’s natural capacity for providing leadership and making a difference as a natural self-expression. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Speaking into the listening}}'''Speaking into the listening.''' Effectively communicating to another such that the communication is heard in the way in which the speaker intended. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Stinginess}}'''Stinginess.''' Deliberately holding oneself and one’s contribution ‘close to the vest’ and without generosity. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Story}}'''Story.''' A "story" is an account or interpretation of past events often mistakenly taken for what actually happened. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Strong suit}}'''Strong suit.''' A way of being and acting one relies on to produce results and make it in life. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) Also called a "winning formula" or "winning way." --[[User:Abd|Abd]] ([[User talk:Abd|discuss]] • [[Special:Contributions/Abd|contribs]]) 22:10, 17 October 2017 (UTC) It is developed and locked in place during stressful periods of life when the young person experiences a failure in being - where their natural way of being doesn't appear sufficient to deal with the situation that occurs, and one thinks, "I need to be ...trait.... like ...admired person". *{{anchor|Superstition}}'''Superstition.''' The system of ideas, beliefs, social and cultural assumptions, and taken-for-granted conclusions, etc., through which an individual interprets and interacts with the world, other people, and himself or herself. <small>[[User:Shinigami Realm|Shinigami Realm]]</small> NOTE: This is not a Landmark term. Just the generic meaning of the word is used in Landmark programs. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) In Landmark it is taken a step further, to challenge the fixed impression of identity and reality by examining the words "I" and "is". *'''{{Anchor}}Throwing your hat over the wall'''. Committing to an outcome without knowing how it can be accomplished, comes from a story told by Irish writer Frank O’Connor of two boys standing beside a tall orchard wall, wanting to pick apples. They didn't know know how they'd get over the wall but they did know they'd get in trouble if they came home without their hats so they threw them over the wall and climbed after them. *{{anchor|Transformation}}'''Transformation.''' The invention of a new realm of possibility for yourself and your life. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) :* The invention of the realm is a necessary condition, but not sufficient for transformation. Without resultant new actions in alignment with the possibilities populating the realm, the invention is just a mental exercise. <small>[[User:AnyTDorH|AnyTDorH]]</small> :* Transformation is used in the sense of a new state of being where the experience is generated from the Self, as a Self-expression instead of from the identity, from the fixed, repetitive patterns of behaviour. *{{anchor|Transformative learning}}'''Transformative learning.''' Transformative learning, gives people an awareness of the basic structures in which one knows, thinks, and acts in the world. From that awareness comes a fundamental shift that leaves people more fully in accord with their own possibilities and those of others. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) :* Transformative learning is contrasted with Informational Learning. Informational learning increases knowledge and ability. Transformative learning results in new perspectives and new abilities (and sometimes disabilities). The common example is of learning to ride a bicycle. Very little information is provided, like "pedal". Suddenly the learner gets balance and is able to ride the bike without help. They have discovered it for themselves, and may never lose the ability to ride a bike. The experience, the learning, transforms the person, their perspective and their abilities. Before they couldn't, now they can. And, a whole new world or realm of possibilities is opened up. <small>[[User:AnyTDorH|AnyTDorH]]</small> * {{Anchor}}'''Trump Card.''' The card you pull out to deflect a challenge to your Act. It appears as an unspoken taunt, challenge or gesture such as "Get lost!" or "Why should I? You're a loser anyway". It is so consistant it is extremely predicable when someone is being their Act and don't realise it, they will simply act out this way every time. *{{anchor|Unreasonable}}'''Unreasonable.''' Not to be mistaken for irrational; it is going beyond one’s reasons, justifications and considerations to act on something one is committed to. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Unreasonable Request}}'''Unreasonable Request.''' A request that requires one to go beyond one’s reasons, justifications and considerations to act on something one is committed to. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{anchor|Vicious circle}}'''Vicious circle.'''™ The human tendency to collapse what happened with the story we tell about what happened. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) :* The story creates a clearing, a listening, for that which supports the story, resulting in more occurrences of things that further support the story, forming a self supporting vicious circle. <small>[[User:AnyTDorH|AnyTDorH]]</small> *{{anchor|What happened}}'''What happened.''' Consensual reality, "objective," aside from judgment, blame, right/wrong, good/bad, and other forms of "meaning." What happens occurs to us as it is analyzed by the Already Always Listening to be good/bad, etc. If my ex-wife told me she had a problem with what I've done, that's what happened. If I say that she was unreasonable, that's my story about it, not what happened. See also ''Story.'' <small>--[[User:Abd|Abd]]</small> NOTE: This is not a Landmark term. Just the generic meaning of the word is used in Landmark programs. [[User:Grantlam|Grantlam]] ([[User talk:Grantlam|discuss]] • [[Special:Contributions/Grantlam|contribs]]) 01:32, 23 September 2016 (UTC) *{{Anchor}}'''Winning Formula'''. See Strong Suit. The Winning Forumula was a later term for this distinction. Terms with "™" are known to be trademarked by Landmark Education. ==Definitions to be added== *Alacrity *At choice (vs. at effect) *At stake *Being *Choice *Commitment *Communication *Competencies *Complaint *Complete *Conspiracy *Dimensions *Fixed way of being *Generate is to choose to create thoughts of possibility and making it happen. Also, making a list of effective actions to move it forward. *Gossip *Got it. means you understand what the other person is saying. *Ideals *Incomplete *Language *Levels of Self *Looking good *No agreement *More, better, different *On the court (or in the stands)- playing the game of life by taking actions and being in the game, not watching from the bleachers. *Principles *Presence of a person *Realm of survival/Realm of enrollment *Self (with a capital S) *Sharing *Significance *Source *Stand *Standards *Technology *Touch, move, or inspire (define the whole phrase as an indicator of enrollment + define each term) *Transform (versus change) *Upset *Values *Velocity *Vitality *What's so ==External Links== *[http://landmarkforum.tribe.net/thread/897acaa1-f09d-412d-aee0-2ff019c2dbd7 landmarkforum.tribe.net] post on "The language of Landmark." *[http://www.whatsthedealaboutlandmark.com/forum_05.htm whatsthedealaboutLandmark.com] post on "What is Landmark jargon?" *[https://www.academia.edu/3789932/Religiosity_Rejected_Exploring_the_Religio-Spiritual_Dimensions_of_Landmark_Education International Journal For the Study of New Religions] "Religiosity Rejected:Exploring the Religio-Spiritual Dimensions of Landmark Education," Renee Lockwood, 2011, pp. 225–254, see page 226-227 for a mention of the language of Landmark. [[Category:Landmark Forum|{{SUBPAGENAME}}]] an5x6x2r76nvs04ryfpfjtkm4nbh51a 0 123684 2413989 2290962 2022-08-12T16:25:23Z Marshallsumter 311529 /* Sun */ wikitext text/x-wiki [[Image:Cp19halphajune29.png|thumb|right|200px|This is a coronagraph/polarimeter image of the solar corona on June 29, 1980, in H alpha light. Credit: NASA.]] A '''coronal cloud''' is a cloud, or cloud-like, natural astronomical entity, composed of [[plasmas]] and usually associated with a [[Stars|star]] or other astronomical object where the temperature is such that X-rays are emitted. While small coronal clouds are above the [[Stars/Photospheres|photosphere]] of many different visual [[w:Spectral type|spectral type]] stars, others occupy parts of the [[interstellar medium]] (ISM), extending sometimes millions of kilometers into space, or thousands of light-years, depending on the size of the associated object such as a [[Stars/Galaxies|galaxy]]. {{clear}} ==Astronomy== {{main|Keynote lectures/Astronomy}} Once an entity, source, or object [such as a corona or coronal cloud] has been detected as emitting, reflecting, absorbing, transmitting, or fluorescing radiation, it may be necessary to determine what the mechanism is. Usually this information provides understanding of the same entity, source, or object. The coronal cloud in close proximity to the Sun also emits X-rays that produce visual fluorescence from gases in a comet's coma and tail. Is the Sun an entity controlling the sky or is it the coronal cloud surrounding the Sun? ==Radiation== "This energy [10³² to 10³³ ergs] appears in the form of electromagnetic radiation over the entire spectrum from γ-rays to radio burst, in fast electrons and nuclei up to relativistic energies, in the creation of a hot coronal cloud, and in large-scale mass motions including the ejections of material from the Sun."<ref name=Lin>{{ cite journal |author=R. P. Lin |author2=H. S. Hudson |title=Non-thermal processes in large solar flares |journal=Solar Physics |month=September-October |year=1976 |volume=50 |issue=10 |pages=153-78 |url=http://adsabs.harvard.edu/full/1976SoPh...50..153L |arxiv= |bibcode=1976SoPh...50..153L |doi=10.1007/BF00206199 |pmid= |accessdate=2013-07-07 }}</ref> ==Planetary sciences== {{main|Planets/Sciences|Planetary sciences}} [[Image:Earth's_x-ray_aurora_borealis_2004_composite.jpg|thumb|200px|right|Bright X-ray arcs of low energy (0.1 - 10 keV) are generated during auroral activity. Instrument: HRC. Credit: NASA/MSFC/CXC/A.Bhardwaj & R.Elsner, et al.; Earth model: NASA/GSFC/L.Perkins & G.Shirah.]] "Auroras are produced by solar storms that eject clouds of energetic charged particles. These particles are deflected when they encounter the Earth’s magnetic field, but in the process large electric voltages are created. Electrons trapped in the Earth’s magnetic field are accelerated by these voltages and spiral along the magnetic field into the polar regions. There they collide with atoms high in the atmosphere and emit X-rays".<ref name=Bhardwaj>{{ cite web |author=A. Bhardwaj |author2=R. Elsner |title=Earth Aurora: Chandra Looks Back At Earth |publisher=Harvard-Smithsonian Center for Astrophysics |location=Cambridge, Massachusetts, USA |date=February 20, 2009 |url=http://chandra.harvard.edu/photo/2005/earth/ |accessdate=2013-05-10 }}</ref> In the image at right are bright X-ray arcs suggestive of the presence of a coronal cloud. The images are superimposed on a simulated image of the Earth. The color code represents brightness, maximum in red. Distance from the North pole to the black circle is {{convert|3,340|km|mi|abbr=on}}. Observation dates: 10 pointings between December 16, 2003 and April 13, 2004. {{clear}} ==Coronal cloud theory== [[File:Van Gogh Sun.ogv|thumb|350px|A new visualisation technique can provide clues to the coronal heating problem.]] Coronal loops have become very important when trying to understand the current ''coronal heating problem''. Coronal loops are highly radiating sources of plasma and therefore easy to observe by instruments such as ''TRACE''; they are highly observable ''laboratories'' to study phenomena such as solar oscillations, wave activity and [[w:Nanoflares|nanoflares]]. However, it remains difficult to find a solution to the coronal heating problem as these structures are being observed remotely, where many ambiguities are present (i.e. radiation contributions along the [[w:Line-of-sight propagation|LOS]]). ''In-situ'' measurements are required before a definitive answer can be arrived at, but due to the high plasma temperatures in the corona, in-situ measurements are impossible (at least for the time being). The next mission of the Nasa [[w:Solar Probe Plus|Solar Probe Plus]] will approach the Sun very closely allowing more direct observations. The ''coronal heating problem'' in solar physics relates to the question of why the temperature of the Sun's corona is millions of kelvin higher than that of the surface. The high temperatures require energy to be carried from the solar interior to the corona by non-thermal processes, because the [[w:second law of thermodynamics|second law of thermodynamics]] prevents heat from flowing directly from the solar photosphere, or surface, at about 5800 K, to the much hotter corona at about 1 to 3 [[w:SI prefix|MK]] (parts of the corona can even reach 10 MK). The thin region of temperature increase from the chromosphere to the corona is known as the [[w:transition region|transition region]] and can range from tens to hundreds of kilometers thick. An analogy of this would be a light bulb heating the air surrounding it hotter than its glass surface. The second law of thermodynamics would be broken. The amount of power required to heat the solar corona can easily be calculated as the difference between [[w:coronal radiative losses|coronal radiative losses]] and heating by thermal conduction toward the [[chromosphere]] through the transition region. It is about 1 kilowatt for every square meter of surface area on the Sun, or 1/40000 of the amount of light energy that escapes the Sun. Many coronal heating theories have been proposed,<ref>{{cite book |last = Ulmshneider |first= Peter |title = Heating of Chromospheres and Coronae in ''Space Solar Physics'', Proceedings, Orsay, France, edited by J.C. Vial, K. Bocchialini and P. Boumier | publisher = Springer | pages = 77–106 | year = 1997 | isbn= 3-540-64307-9 }}</ref> but two theories have remained as the ''most likely'' candidates, ''wave heating'' and ''magnetic reconnection'' (or ''nanoflares'').<ref>{{cite book |last = Malara F., Velli M. |title = Observations and Models of Coronal Heating in ''Recent Insights into the Physics of the Sun and Heliosphere: Highlights from SOHO and Other Space Missions'', Proceedings of IAU Symposium 203, edited by Pål Brekke, Bernhard Fleck, and Joseph B. Gurman | publisher = Astronomical Society of the Pacific | pages = 456–466 | year = 2001 | isbn= 1-58381-069-2 }}</ref> Through most of the past 50 years, neither theory has been able to account for the extreme coronal temperatures. {| class="wikitable" style="margin: 1em auto 1em auto" |+'''Competing heating mechanisms''' |- ! colspan="3" |Heating Models |- ! Hydrodynamic ! colspan="2" |Magnetic |- | rowspan="2" | * No magnetic field * Slow rotating stars ! [[Direct current|DC]] (''reconnection'') ! [[Alternating current|AC]] (''waves'') |- | * B-field stresses * Reconnection events * [[w:Solar flare|Flares]]-nanoflares * ''Uniform heating rates'' | * Photospheric foot point ''shuffling'' * MHD wave propagation * High Alfvén wave flux * ''Non-uniform heating rates'' |- ! Not our Sun! ! colspan="2" |Competing theories |} Magnetic reconnection is hypothesized to be the mechanism behind solar flares, the largest explosions in our solar system. Furthermore, the surface of the Sun is covered with millions of small magnetized regions 50–1,000&nbsp;km across. These small magnetic poles are buffeted and churned by the constant granulation. The magnetic field in the solar corona must undergo nearly constant reconnection to match the motion of this "magnetic carpet", so the energy released by the reconnection is a natural candidate for the coronal heat, perhaps as a series of "microflares" that individually provide very little energy but together account for the required energy. '''Def.''' the "luminous plasma atmosphere of the Sun or other star, extending millions of kilometres into space, most easily seen during a total solar eclipse"<ref name=CoronaWikt>{{ cite book |title=corona |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=May 9, 2012 |url=http://en.wiktionary.org/wiki/corona |accessdate=2012-06-28 }}</ref> is called a '''corona''', or '''stellar corona'''. {{clear}} ==Entities== {{main|Radiation astronomy/Entities|Entities}} Historical evidence exists for the phrase "coronal cloud" with respect to "a cloud, or cloud-like, natural astronomical entity, composed of [[plasmas]], at least hot enough to emit X-rays". For now this may serve as a working definition. '''Def.''' a cloud, or cloud-like, natural astronomical entity, composed of plasmas at least hot enough to emit X-rays is called a '''coronal cloud'''. The idea that nanoflares might heat the corona was put forward by [[w:Eugene Parker|Eugene Parker]] in the 1980s but is still controversial. In particular, ultraviolet telescopes such as [[w:TRACE|TRACE]] and [[w:Solar and Heliospheric Observatory|SOHO]]/EIT can observe individual micro-flares as small brightenings in extreme ultraviolet light,<ref name=Patsourakos>{{cite journal | doi = 10.1051/0004-6361:20020151 | author =S. Patsourakos |author2=J.-C. Vial | title = Intermittent behavior in the transition region and the low corona of the quiet Sun | journal = Astronomy and Astrophysics | volume = 385 | pages = 1073–1077 | year = 2002 | bibcode=2002A&A...385.1073P }}</ref> but there seem to be too few of these small events to account for the energy released into the corona. The additional energy not accounted for could be made up by wave energy, or by gradual magnetic reconnection that releases energy more smoothly than micro-flares and therefore doesn't appear well in the TRACE data. Variations on the micro-flare hypothesis use other mechanisms to stress the magnetic field or to release the energy, and are a subject of active research in 2005. ==Sources== {{main|Radiation astronomy/Sources|Radiation astronomy sources|Sources}} As of December 5, 2011, "Voyager 1 is about ... 18 billion kilometers ... from the [S]un [but] the direction of the magnetic field lines has not changed, indicating Voyager is still within the heliosphere ... the outward speed of the solar wind had diminished to zero in April 2010 ... inward pressure from interstellar space is compacting [the magnetic field] ... Voyager has detected a 100-fold increase in the intensity of high-energy electrons from elsewhere in the galaxy diffusing into our solar system from outside ... [while] the [solar] wind even blows back at us."<ref name=Cole>{{ cite web |author=Steve Cole |author2=Jia-Rui C. Cook |author3=Alan Buis |title=NASA's Voyager Hits New Region at Solar System Edge |publisher=NASA |location=Washington, DC |date=December 2011 |url=http://www.nasa.gov/home/hqnews/2011/dec/HQ_11-402_AGU_Voyager.html |accessdate=2012-02-09 }}</ref> "[P]ower spectra intrinsic to the source can be severely attenuated at high frequencies by scattering in a hot coronal cloud with the amount of attenuation depending on optical depth and cloud radius."<ref name=KSWood>{{ cite web |author=Kent S. Wood |author2=Peter F. Michelson |author3=Mallory S. Roberts |title=A Modified Beat Frequency Modulated Accretion Model I. Spin Periods and Magnetic Moments of Z-Sources Inferred from Horizontal Branch QPO. |publisher=Stanford University |location=Palo Alto, California USA |date= 1996 |url=http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA327573 |accessdate=2013-07-10 }}</ref> A Z source is a low-mass X-ray binary exhibiting a Z-type X-ray intensity profile, as resembling the letter "Z". ==Objects== {{main|Radiation astronomy/Objects|Object astronomy|Objects}} "Coronal clouds are irregular objects suspended in the corona with matter streaming out of them into nearby active regions."<ref name=Tandberg>{{ cite book |author=E. Tandberg-Hanssen |title=Prominences, In: ''Illustrated Glossary for Solar and Solar-Terrestrial Physics'' |publisher=D. Reidel Publishing Company |location=Dordrecht-Holland |year=1977 |editor=A. Bruzek and C. J. Durrant |pages=97-109 |url=http://link.springer.com/chapter/10.1007/978-94-010-1245-4_10 |arxiv= |bibcode= |doi=10.1007/978-94-010-1245-4_10 |pmid= |isbn=978-94-010-1247-8 |accessdate=2013-07-10 }}</ref> "Objects identified as X-ray bright points show complex resolved structure; but a new class of bright points connected with satellite polarity was smaller and more complex."<ref name=Golub/> "The object of interest here is the bright streamer in the southeast quadrant."<ref name=Koomen>{{ cite journal |author=Martin Koomen |author2=Russell Howard |author3=Richard Hansen |author4=Shirley Hansen |title=The coronal transient of 16 June 1972 |journal=Solar Physics |month=February |year=1974 |volume=34 |issue=2 |pages=447-52 |url=http://link.springer.com/article/10.1007/BF00153680 |arxiv= |bibcode= |doi=10.1007/BF00153680 |pmid= |accessdate=2013-07-10 }}</ref> ==Continua== {{main|Radiation astronomy/Continua|Continuum astronomy|Continua}} "High time resolution videotapes of the blue continuum show no fluctuations faster than a few seconds."<ref name=Tanaka>{{ cite journal |author=Katsuo Tanaka, Harold Zirin |title=The great flare of 1982 June 6 |journal=The Astrophysical Journal |month=December 15, |year=1985 |volume=299 |issue=12 |pages=1036-46 |url=http://adsabs.harvard.edu/full/1985ApJ...299.1036T |arxiv= |bibcode=1985ApJ...299.1036T |doi=10.1086/163771 |pmid= |accessdate=2013-07-10 }}</ref> "All parameters seem to have broad or unimodal distributions, suggesting that flares and CMEs form a continuum with the same underlying physics."<ref name=Hudson1997>{{ cite book |author=Hugh S. Hudson |author2=D. F. Webb |title=Soft X-ray signatures of coronal ejections, In: ''Coronal Mass Ejections'' |publisher=American Geophysical Union |location=Washington, DC USA |series=Geophysical Monograph Series |year=1997 |editor=N. Crooker |editor2=J. A. Joselyn |editor3=J. Feynman |volume=99 |issue= |pages=27-38 |url=http://www.agu.org/books/gm/v099/GM099p0027/GM099p0027.shtml |arxiv= |bibcode= |doi=10.1029/GM099p0027 |pmid= |isbn= |accessdate=2013-07-10 }}</ref> "At the NIXT wavelength, the opacity will be dominated by Lyman-continuum absorption of neutral H and He."<ref name=Golub>{{ cite journal |author=Leon Golub |author2=Harold Zirin |author3=Haimin Wang |title=The roots of coronal structure in the Sun's surface |journal=Solar Physics |month=August |year=1994 |volume=153 |issue=1-2 |pages=179-98 |url=http://link.springer.com/article/10.1007/BF00712500 |arxiv= |bibcode=1994SoPh..153..179G |doi=10.1007/BF00712500 |pmid= |accessdate=2013-07-10 }}</ref> "The peak continuum intensity was always at the loop tops."<ref name=Zirin1981>{{ cite journal |author=H. Zirin |author2=U. Feldman |author3=G. A. Doschek |author4=S. Kane |title=On the relationship between soft X-rays and Hα-emitting structures during a solar flare |journal=The Astrophysical Journal |month=May 15, |year=1981 |volume=246 |issue=05 |pages=321-30 |url=http://adsabs.harvard.edu/full/1981ApJ...246..321Z |arxiv= |bibcode=1981ApJ...246..321Z |doi=10.1086/158925 |pmid= |accessdate=2013-07-10 }}</ref> ==Bands== {{main|Radiation astronomy/Bands|Band astronomy}} "In the L-band, a diffuse single source is observed. It is located between the two ribbons observed in the higher-energy bands."<ref name=Masuda>{{ cite journal |author=S. Masuda |author2=T. Kosugi |author3=Hugh S. Hudson |title=A hard X-ray two-ribbon flare observed with Yohkoh/HXT |journal=Solar Physics |month=December |year=2001 |volume=204 |issue=1-2 |pages=57-69 |url=http://link.springer.com/article/10.1023/A:1014230629731 |arxiv= |bibcode= |doi=10.1023/A:1014230629731 |pmid= |accessdate=2013-07-10 }}</ref> "They also roughly match the off-band Hα images, ie, the region of broad Hα profile."<ref name=Tanaka/> "A flare mode normally triggers at about the C2 level, 2 x 10³ ergs (cm² sec)^-1 in the 1-8 A band."<ref name=Hudson1997a>{{ cite book |author=Hugh S. Hudson |title=Solar antecedents of geomagnetic storms, In: ''Coronal Mass Ejections'' |publisher=American Geophysical Union |location=Washington, DC USA |series=Geophysical Monograph Series |year=1997 |editor=N. Crooker |editor2=J. A. Joselyn |editor3=J. Feynman |volume=99 |issue= |pages=27-38 |url=http://www.agu.org/books/gm/v099/GM099p0027/GM099p0027.shtml |arxiv= |bibcode= |doi=10.1029/GM099p0027 |pmid= |isbn= |accessdate=2013-07-10 }}</ref> ==Backgrounds== {{main|Backgrounds/Astronomy|Background astronomy}} For coronal cloud observations of the Large Magellanic Cloud, "[b]ackground spectra were obtained from observations of the Lockman Hole."<ref name=Steiner>{{ cite journal |author=James F. Steiner |author2=Rubens C. Reis |author3=Andrew C. Fabian |author4=Ronald A. Remillard |author5=Jeffrey E. McClintock |author6=Lijun Gou |author7=Ryan Cooke |author8=Laura W. Brenneman |author9=Jeremy S. Sanders |title=A broad iron line in LMC X‐1 |journal=Monthly Notices of the Royal Astronomical Society |month=December 11, |year=2012 |volume=427 |issue=3 |pages=2552-61 |url=http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2966.2012.22128.x/full |arxiv= |bibcode= |doi=10.1111/j.1365-2966.2012.22128.x |pmid= |accessdate=2013-07-10 }}</ref> "With longer exposures and instruments whose stray light background is low, it is probable that there would be observed at least as many emission lines per nanometre as there are Fraunhofer lines per nanometre at longer wavelengths."<ref name=Tousey>{{ cite journal |author=R. Tousey |title=Chromosphere and Corona: Observations of the Extreme Ultraviolet Solar Spectrum |journal=Philosophical Transactions of the Royal Society London. A Mathematical, Physical & Engineering Sciences |month=July 16, |year=1971 |volume=270 |issue=1202 |pages=59-70 |url=http://rsta.royalsocietypublishing.org/content/270/1202/59.short |arxiv= |bibcode= |doi=10.1098/rsta.1971.0060 |pmid= |accessdate=2013-07-10 }}</ref> "In between is an irregular continuous background field of about 0.05 gauss, which Zhang and Zirin recently found had a net polarity opposite the dominant field in that hemisphere."<ref name=Zirin1997>{{ cite journal |author=H. Zirin |title= Is There a Background Polar Field? |journal=Bulletin of the American Astronomical Society |month=May |year=1997 |volume=29 |issue=05 |pages=902 |url=http://esoads.eso.org/abs/1997SPD....28.0250Z |arxiv= |bibcode=1997SPD....28.0250Z |doi= |pmid= |accessdate=2013-07-10 }}</ref> ==Temperatures== {{main|Physics/Temperatures|Temperatures}} The high temperature of the coronal cloud gives it unusual [[w:Spectral|spectral]] features. These features have been traced to highly ionized atoms of elements such as iron which indicate a plasma's [[w:Temperature|temperature]] in excess of 10⁶ Kelvin (MK). Although a coronal cloud (as part or all of a stellar or galactic corona) is usually "filled with high-temperature plasma at temperatures of T ≈ 1–2 (MK), ... [h]ot active regions and postflare loops have plasma temperatures of T ≈ 2–40 MK."<ref name=Aschwanden>{{ cite journal |author=Markus J. Aschwanden |title=Fundamental Physical Processes in Coronae: Waves, Turbulence, Reconnection, and Particle Acceleration In: ''Waves & Oscillations in the Solar Atmosphere: Heating and Magneto-Seismology'' |journal=Proceedings IAU Symposium |year=2007 |editor=Erdelyi R |volume=3 |issue= S247 |pages=257–68 |arxiv=0711.0007 |url=http://journals.cambridge.org/download.php?file=%2FIAU%2FIAU3_S247%2FS1743921308014956a.pdf&code=7c95b408db74ccbe9f1f376d4cb1ef35 |doi=10.1017/S1743921308014956 }}</ref> ==Coronal heating== {{main|Plasmas/Plasma objects/Coronal clouds/Heating|Coronal heating}} "The [[Stars/Photospheres|photosphere]] of the Sun has an effective temperature of 5,570 K<ref name=Massey>{{ cite journal |author=Massey P |author2=Silva DR |author3=Levesque EM |author4=Plez B |author5=Olsen KAG |author6=Clayton GC |author7=Meynet G |author8=Maeder A |title=Red Supergiants in the Andromeda Galaxy (M31) |journal=The Astrophysical Journal |volume=703 |year=2009 |issue=1 |page=420 |doi=10.1088/0004-637X/703/1/420 |bibcode=2009ApJ...703..420M }}</ref> yet its corona has an average temperature of 1–2 x 10⁶ K.<ref name=Erdelyi>{{ cite journal |author=Erdèlyi R |author2=Ballai I |title=Heating of the solar and stellar coronae: a review |year=2007 |journal=Astron Nachr |volume=328 |issue=8 |page=726 |doi=10.1002/asna.200710803 |bibcode=2007AN....328..726E }}</ref> However, the hottest regions are 8–20 x 10⁶ K.<ref name=Erdelyi/> The high temperature of the corona shows that it is heated by something other than direct [[w:Heat conduction|heat conduction]] from the photosphere.<ref name=Russell2001>{{ cite book |author=Russell CT |title=Space Weather (Geophysical Monograph) |year=2001 |publisher=American Geophysical Union |chapter=Solar wind and interplanetary magnetic field: A tutorial |editor=Song, Paul |editor2=Singer, Howard J. |editor3=Siscoe, George L. |isbn=9780875909844 |pages=73–88 |url=http://www-ssc.igpp.ucla.edu/personnel/russell/papers/SolWindTutorial.pdf }}</ref> It is thought that the energy necessary to heat the corona is provided by turbulent motion in the convection zone below the photosphere, and two main mechanisms have been proposed to explain coronal heating.<ref name=Erdelyi/> The first is [[w:wave|wave]] heating, in which sound, gravitational or magnetohydrodynamic waves are produced by turbulence in the convection zone.<ref name=Erdelyi/> These waves travel upward and dissipate in the corona, depositing their energy in the ambient gas in the form of heat.<ref name=Alfven>{{ cite journal |author=Alfvén H |title=Magneto-hydrodynamic waves, and the heating of the solar corona |bibcode=1947MNRAS.107..211A |journal=Monthly Notices of the Royal Astronomical Society |volume=107 |page=211 |year=1947 }}</ref> The other is [[w:magnetic field|magnetic]] heating, in which magnetic energy is continuously built up by photospheric motion and released through [[w:magnetic reconnection|magnetic reconnection]] in the form of large [[w:solar flare|solar flare]]s and myriad similar but smaller events—[[w:nanoflares|nanoflares]].<ref name=Parker2>{{ cite journal |author=Parker EN |title=Nanoflares and the solar X-ray corona |journal=The Astrophysical Journal |volume=330 |page=474 |year=1988 |doi=10.1086/166485 |bibcode=1988ApJ...330..474P }}</ref> Currently, it is unclear whether waves are an efficient heating mechanism. All waves except [[w:Alfvén wave|Alfvén wave]]s have been found to dissipate or refract before reaching the corona.<ref name=Sturrock>{{ cite journal |author=Sturrock PA, Uchida Y |title=Coronal heating by stochastic magnetic pumping |journal=The Astrophysical Journal |volume=246 |page=331 |year=1981 |doi=10.1086/158926 |bibcode=1981ApJ...246..331S }}</ref> In addition, Alfvén waves do not easily dissipate in the corona. Current research focus has therefore shifted towards flare heating mechanisms.<ref name=Erdelyi/>"<ref name=XrayAstronomy>{{ cite web |title=X-ray astronomy, In: ''Wikipedia'' |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=June 11, 2012 |url=http://en.wikipedia.org/wiki/X-ray_astronomy |accessdate=2012-06-29 }}</ref> ==Meteors== {{main|Radiation astronomy/Meteors|Meteor astronomy|Meteors}} [[Image:Coronal Mass Ejection.gif|thumb|right|250px|Arcs rise above an active region on the surface of the Sun in this series of images taken by the STEREO (Behind) spacecraft. Credit: Images courtesy of the NASA STEREO Science Center.]] A '''magnetic cloud''' is a transient event observed in the [[w:solar wind|solar wind]]. It was defined in 1981 by Burlaga et al. 1981 as a region of enhanced [[w:magnetic field|magnetic field]] strength, smooth rotation of the magnetic field vector and low [[w:proton|proton]] temperature <ref name=Burlaga>Burlaga, L. F., E. Sittler, F. Mariani, and R. Schwenn, "Magnetic loop behind an interplanetary shock: Voyager, Helios and IMP-8 observations" in "Journal of Geophysical Research", 86, 6673, 1981</ref>. Magnetic clouds are a possible manifestation of a [[w:Coronal Mass Ejection|Coronal Mass Ejection]] (CME). The association between CMEs and magnetic clouds was made by Burlaga et al. in 1982 when a magnetic cloud was observed by [[w:Helios probes|Helios-1]] two days after being observed by [[w:Solar Maximum Mission|SMM]]<ref name=Burlaga82>Burlaga, L. F. et al., "A magnetic cloud and a coronal mass ejection" in "Geophysical Research Letter"s, 9, 1317-1320, 1982</ref>. However, because observations near Earth are usually done by a single spacecraft, many CMEs are not seen as being associated with magnetic clouds. The typical structure observed for a fast CME by a satellite such as [[w:Advanced Composition Explorer|ACE]] is a fast-mode [[w:shock wave|shock wave]] followed by a dense (and hot) sheath of plasma (the downstream region of the shock) and a magnetic cloud. Other signatures of magnetic clouds are now used in addition to the one described above: among other, bidirectional superthermal electrons, unusual charge state or abundance of iron, helium, carbon and/or oxygen. The typical time for a magnetic cloud to move past a satellite at the [[w:Lagrange Point|L1]] point is 1 day corresponding to a radius of 0.15 [[w:Astronomical Unit|AU]] with a typical speed of 450&nbsp;km s⁻¹ and magnetic field strength of 20 nT <ref name=Lepping>Lepping, R. P. et al. "Magnetic field structure of interplanetary magnetic clouds at 1 AU" in "Journal of Geophysical Research", 95, 11957-11965, 1990.</ref> '''Def.''' a "massive burst of solar wind, other light isotope plasma, and magnetic fields rising above the solar corona or being released into space"<ref name=CoronalMassEjectionWikt>{{ cite book |title=coronal mass ejection |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=June 21, 2013 |url=http://en.wiktionary.org/wiki/coronal_mass_ejection |accessdate=2013-07-07 }}</ref> is called a '''coronal mass ejection''' (CME). An explosive limb flare occurred above 30,000 km in the corona of the [[Sun (star)|Sun]].<ref name=Zirin/> "So the aftermath of the flare explosion, usually visible in disk pictures as extensive Hα brightening, but hidden from us in this case, was seen by the ionosphere as an intense flux of ionizing radiation from the coronal cloud created by the explosion."<ref name=Zirin>{{ cite journal |author=Harold Zirin |title=The Limb Flare of November 20, 1960: a Coronal Phenomenon |journal=Astrophysical Journal |month=October |year=1964 |volume=140 |issue=10 |pages=1216-35 |url= |bibcode=1964ApJ...140.1216Z |doi=10.1086/148019 |pmid= |accessdate=2011-08-01 }}</ref> "The November 20, 1960, event is very similar to that of February 10, 1956, which was observed at Sacramento Peak. A bright ball appears above the surface, grows in size and Hα brightness, and explodes upward and outward."<ref name=Zirin/> "The great breadth and intensity of the Hα emission from the suspended ball at 2013 U.T. testify to the large amount of energy stored there, as no corresponding macroscopic motion was observed until the explosion at 2023 U.T."<ref name=Zirin/> "[T]he great energy of the preflare cloud was released into the corona by the explosion of 2023 U.T., and Hα radiation disappeared by 2035 U.T."<ref name=Zirin/> "On 16 June 1972, the [[w:Naval Research Laboratory|Naval Research Laboratory]]'s coronagraph aboard [[w:OSO-7|OSO-7]] tracked a huge coronal cloud moving outward from the [[Sun (star)|Sun]]."<ref name=Koomen/> A [[w:coronal mass ejection|coronal mass ejection]] (CME) is an ejected plasma consisting primarily of electrons and [[w:proton|proton]]s (in addition to small quantities of heavier elements such as helium, oxygen, and iron), plus the entraining coronal closed magnetic field regions. Evolution of these closed magnetic structures in response to various photospheric motions over different time scales (convection, differential rotation, meridional circulation) somehow leads to the CME.<ref name=Gopalswamy>{{ cite journal |author=Gopalswamy N |author2=Mikic Z |author3=Maia D |author4=Alexander D |author5=Cremades H |author6=Kaufmann P |author7=Tripathi D |author8=Wang YM |title=The pre-CME Sun |journal=Space Sci Rev |year=2006 |volume=123 |issue=1–3 |page=303 |doi=10.1007/s11214-006-9020-2 |bibcode = 2006SSRv..123..303G }}</ref> Small-scale energetic signatures such as plasma heating (observed as compact soft X-ray brightening) may be indicative of impending CMEs. The soft X-ray sigmoid (an S-shaped intensity of soft X-rays) is an observational manifestation of the connection between coronal structure and CME production.<ref name=Gopalswamy/> "Relating the sigmoids at X-ray (and other) wavelengths to magnetic structures and current systems in the solar atmosphere is the key to understanding their relationship to CMEs."<ref name=Gopalswamy/> {{clear}} ==Cosmic rays== {{main|Radiation astronomy/Cosmic rays|Cosmic-ray astronomy|Cosmic rays}} "[C]oronal magnetic bottles, produced by flares, [may] serve as temporary traps for solar cosmic rays ... It is the expansion of these bottles at velocities of 300–500 km/s which allows fast azimuthal propagation of solar cosmic rays independent of energy. A coronagraph on [[w:OSO 7|Os 7]] observed a coronal cloud which was associated with bifurcation of the underlying coronal structure."<ref name=Schatten>{{ cite journal |author=K. H. Schatten, D. J. Mullan |title=Fast azimuthal transport of solar cosmic rays via a coronal magnetic bottle |journal=Journal of Geophysical Research |month=December 1, |year=1977 |volume=82 |issue=35 |pages=5609-20 |url=http://www.agu.org/pubs/crossref/1977/JA082i035p05609.shtml |arxiv= |bibcode= |doi=10.1029/JA082i035p05609 |pmid= |accessdate=2013-07-07 }}</ref> ==Neutrons== {{main|Radiation astronomy/Neutrons|Neutron astronomy|Neutrons}} "The neutrons are produced by the energetic protons interacting with a number of different nuclei."<ref name=Lin/> ==Protons== {{main|Radiation astronomy/Protons|Proton astronomy|Protons}} "On 16 June 1972, the Naval Research Laboratory's coronagraph aboard OSO-7 tracked a huge coronal cloud moving outward from the Sun. ... This event is of great interest in its own right because it is the probable source of the solar proton event (Solar-Geophysical Data, NOAA Boulder) and shock-produced interplanetary scintillations (Dennison, 1972) which began early on 16 June."<ref name=Koomen/> ==Electrons== {{main|Radiation astronomy/Electrons|Electrons}} "The density of the coronal cloud deduced in this case is about 2 x 10¹¹ electrons per cubic centimeter."<ref name=Zinn1965>{{ cite book |author=H. Zinn |title=Solar Flares and Concurrent Phenomena in the Solar Atmosphere, In: ''Proceedings of the Plasma Space Science Symposium'' |publisher=Springer |location=Netherlands |year=1965 |editor=C. C. Chang and S. S. Huang |volume=3 |issue= |pages=38-51 |url=http://link.springer.com/chapter/10.1007/978-94-011-7542-5_5 |arxiv= |bibcode= |doi=10.1007/978-94-011-7542-5_5 |pmid= |isbn=978-94-011-7544-9 |accessdate=2013-07-07 }}</ref> ==Positrons== {{main|Radiation astronomy/Positrons|Positron astronomy|Positrons}} "On the basis of spectroscopic observations, the leading models of the X-ray continuum production are based on a hot, Comptonizing electron or electron-positron pair corona close to the black hole."<ref name=Markowitz>{{ cite journal |author=A. Markowitz |author2=R. Edelson |title=An expanded Rossi X-ray timing explorer survey of X-ray variability in Seyfert 1 galaxies |journal=The Astrophysical Journal |month=December 20, |year=2004 |volume=617 |issue=2 |pages=939-65 |url=http://iopscience.iop.org/0004-637X/617/2/939 |arxiv=astro-ph/0409045 |bibcode=2004ApJ...617..939M |doi=10.1086/425559 |pmid= |accessdate=2013-07-07 }}</ref> ==Neutrinos== {{main|Radiation astronomy/Neutrinos|Neutrino astronomy|Neutrinos}} [[Image:Proton proton cycle.png|thumb|right|200px|The diagram contains the reactions in the proton-proton chain including neutrino production. Credit: [[w:User:SzDóri|Dorottya Szam]].]] "The highest flux of solar neutrinos come directly from the proton-proton interaction, and have a low energy, up to 400 keV. There are also several other significant production mechanisms, with energies up to 18 MeV. <ref name=Bellerive>A. Bellerive, [http://arxiv.org/abs/hep-ex/0312045 Review of solar neutrino experiments]. Int.J.Mod.Phys. A19 (2004) 1167-1179</ref>"<ref name=SolarNeutrino>{{ cite web |title=Solar neutrino, In: ''Wikipedia'' |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=April 4, 2012 |url=http://en.wikipedia.org/wiki/Solar_neutrino |accessdate=2012-11-08 }}</ref> "The parts of the Sun above the photosphere are referred to collectively as the ''solar atmosphere''.<ref name=Abhyankar1977>{{ cite journal |author=K.D. Abhyankar |title=A Survey of the Solar Atmospheric Models |year=1977 |journal=Bull. Astr. Soc. India |volume=5 |bibcode=1977BASI....5...40A|pages=40–44 |url=http://prints.iiap.res.in/handle/2248/510 }}</ref>"<ref name=Sun>{{ cite web |title=Sun, In: ''Wikipedia'' |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=June 29, 2013 |url=http://en.wikipedia.org/wiki/Sun |accessdate=2013-07-07 }}</ref> "Neutrinos can be produced by energetic protons accelerated in solar magnetic fields. Such protons produce pions, and therefore muons, hence also neutrinos as a decay product, in the solar atmosphere."<ref name=Bahcall>{{ cite journal |author=J. N. Bahcall |author2=G. B. Field |author3=W. H. Press |title=Is solar neutrino capture rate correlated with sunspot number? |journal=The Astrophysical Journal |month=September 1, |year=1987 |volume=320 |issue=9 |pages=L69-73 |url=http://articles.adsabs.harvard.edu//full/1987ApJ...320L..69B/L000069.000.html |arxiv= |bibcode=1987ApJ...320L..69B |doi=10.1086/184978 |pmid= |accessdate=2013-07-07 }}</ref> "Energetic protons in the solar corona could explain Figure 2 only if (1) they tap a substantial fraction of the entire energy generated in the corona, (2) the energy generated in the corona is at least 3 times what has been deduced from the observations, (3) the vast majority of energetic protons do not escape the Sun, (4) the proton energy spectrum is unusually hard (''p''₀ = 300 MeV c^-1, and (5) the sign of the variation is opposite to what one would predict. As the likelihood of all of these conditions being fulfilled seems extremely small, we do not believe that neutrinos produced by energetic protons in the solar atmosphere contribute significantly to the neutrino capture in the ³⁷Cl experiment."<ref name=Bahcall/> ==Gamma rays== {{main|Radiation astronomy/Gamma rays|Gamma-ray astronomy|Gamma rays}} "The 2.2 MeV line is formed in the reaction which synthesizes deuterium: ¹H(n,γ)²H ... The line has been observed in a number of solar flares by the SMM, Hinotori and Prognoz satellites".<ref name=Terekhov/> "The 2.2-MeV line fluence throughout the [May 24, 1990] flare was 345 ± 6 photons/cm², which corresponds to the observed synthesis of over 3 tons [some ~3.3 metric tons] of deuterium on the solar surface."<ref name=Terekhov>{{ cite journal |author=O. V. Terekhov |author2=R. A. Syunyaev |author3=A. V. Kuznetsov |author4=C. Barat |author5=R. Talon |author6=G. Trottet |author7=N. Vilmer |title=Deuterium synthesis in the solar flare on 24 May 1990: observations of delayed emission in the 2.2 Mev γ-ray line by the GRANAT satellite |journal=Astronomy Letters |month=March |year=1993 |volume=19 |issue=03 |pages=65-8 |url= |arxiv= |bibcode=1993AstL...19...65T |doi= |pmid= |accessdate=2012-11-11 }}</ref> "Surface fusion is no longer bizarre since the 2.2 MeV gamma ray line of the P(n,γ)D reaction was observed<ref name=Terekhov/> during the solar flare of May 24 1990."<ref name=Dubin>{{ cite journal |author=Maurice Dubin |author2=Robert K. Soberman |title=Resolution of the Solar Neutrino Anomaly |journal=arXiv |month=April |year=1996 |volume= |issue= |pages=1-8 |url=http://arxiv.org/abs/astro-ph/9604074 |arxiv=astro-ph/9604074 |bibcode=1996astro.ph..4074D |doi= |pmid= |pdf=http://arxiv.org/pdf/astro-ph/9604074.pdf |accessdate=2012-11-11 }}</ref> "[M]ost of the sun’s fusion must occur near the surface rather than the core."<ref name=Dubin/> ==X-rays== {{main|Radiation astronomy/X-rays|X-ray astronomy|X-rays}} "The origin of all observed astronomical X-ray sources is in, near to, or associated with a coronal cloud or gas at coronal cloud temperatures for however long or brief a period."<ref name=AstrophysicalXraysource>{{ cite web |title=Astrophysical X-ray source, In: ''Wikipedia'' |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=June 12, 2012 |url=http://en.wikipedia.org/wiki/Astrophysical_X-ray_source |accessdate=2012-06-28 }}</ref> ==Ultraviolets== {{main|Radiation astronomy/Ultraviolets|Ultraviolet astronomy}} [[Image:August 2010 CME SDO.jpg|thumb|right|200px|A coronal mass ejection is shown in the ultraviolet. Credit: NASA/SDO.]] "One of the fastest CMEs in years was captured by the STEREO COR1 telescopes on August 1, 2010. ... This CME is seen to be heading towards Earth at speeds well over 1000 kilometers per second."<ref name=Zell/> "On August 1st, almost the entire Earth-facing side of the sun erupted in a tumult of activity. There was a C3-class solar flare, a solar tsunami, multiple filaments of magnetism lifting off the stellar surface, large-scale shaking of the solar corona, radio bursts, a coronal mass ejection and more. This extreme ultraviolet snapshot [at right] from the Solar Dynamics Observatory (SDO) shows the sun's northern hemisphere in mid-eruption. Different colors in the image represent different gas temperatures ranging from ~1 to 2 million degrees K."<ref name=Zell>{{ cite book |author=Holly Zell |title=Spacecraft Observes Coronal Mass Ejection |publisher=NASA |location=Washington, DC USA |date=August 4, 2010 |url=http://www.nasa.gov/topics/solarsystem/sunearthsystem/main/News080210-cme.html |accessdate=2013-07-07 }}</ref> {{clear}} ==Opticals== {{main|Radiation astronomy/Opticals|Optical astronomy|Opticals}} [[Image:X-ray image of the Pleiades.gif|thumb|right|200px|The image shows the Pleiades in X-rays, taken by ROSAT, where the brightest optical stars are inside the green squares. Credit: [[w:User:Worldtraveller|Worldtraveller]].]] "The Pleiades star cluster is one of the jewels of the northern sky. To the unaided eye it appears as an alluring group of stars in the constellation Taurus, while telescopic views reveal cluster stars surrounded by delicate blue wisps of dust-reflected starlight. To the X-ray telescopes on board the orbiting ROSAT observatory, the cluster also presents an impressive, but slightly altered, appearance. This false color image [at right] was produced from ROSAT observations by translating different X-ray energy bands to visual colors - the lowest energies are shown in red, medium in green, and highest energies in blue. (The green boxes mark the position of the seven brightest visual stars.) The Pleiades stars seen in X-rays have extremely hot, tenuous outer atmospheres called coronas and the range of colors corresponds to different coronal temperatures."<ref name=Nemiroff1999>{{ cite book |author=Robert Nemiroff |author2=Jerry Bonnell |title=X-Ray Pleiades |publisher=NASA/GSFC |location=Greenbelt, Maryland USA |date=August 28, 1999 |url=http://apod.nasa.gov/apod/ap990828.html |accessdate=2013-07-07 }}</ref> {{clear}} ==Visuals== {{main|Radiation astronomy/Visuals|Visual astronomy|Visuals}} [[Image:Solar eclipse 2006-03-28, The sun's corona, or outer atmosphere, is visible during totality.jpg|thumb|right|200px|During the solar eclipse of March 28, 2006, the coronal cloud around the Sun is visible. Credit: NASA TV.]] "NASA gave people a front row seat to today's total solar eclipse, thanks to a partnership with the University of California at Berkeley and the Exploratorium. A streaming webcast brought the eclipse -- visible along a path from South America to Africa to Asia -- to schools and museums and computer desktops worldwide. ... The sun's corona, or outer atmosphere, is visible during totality -- when the sun is totally obscured by the [M]oon's shadow."<ref name=Jenner>{{ cite web |author=Lynn Jenner |title=NASA Shares Solar Eclipse With the World |publisher=NASA |location=Washington, DC USA |date=November 30, 2007 |url=http://www.nasa.gov/vision/universe/solarsystem/sun_earthday2006.html |accessdate=2013-07-08 }}</ref> {{clear}} ==Violets== {{main|Radiation astronomy/Violets|Violet astronomy|Violets}} Calcium has a line occurring in the solar corona at 408.63 nm of Ca XIII.<ref name=Swings/> Iron has a line occurring in the solar corona in the violet at 398.69 nm of Fe XI.<ref name=Swings>{{ cite journal |author=P. Swings |title=Edlén's Identification of the Coronal Lines with Forbidden Lines of Fe X, XI, XIII, XIV, XV; Ni XII, XIII, XV, XVI; Ca XII, XIII, XV; a X, XIV |journal=The Astrophysical Journal |month=July |year=1943 |volume=98 |issue=07 |pages=116-28 |url= |arxiv= |bibcode=1943ApJ....98..116S |doi=10.1086/144550 |pmid= |accessdate=2013-01-18 }}</ref> Nickel has three emission lines occurring in the solar corona at 380.08 nm of Ni XIII and 423.14 nm and 431.1 of Ni XII.<ref name=Swings/> ==Blues== {{main|Radiation astronomy/Blues|Blue astronomy|Blues}} "[B]ound electrons in the corona [may be] scattering blue light according to RAYLEIGH'S law ... [The scattering coefficients and the intensities scattered] for blue and yellow light are in the proportion 37/11 = 3,36 [thus] the scattering must be due to bound electrons, belonging to ions or atoms."<ref name=Minnaert>{{ cite journal |author=M. Minnaert |title=On the continuous spectrum of the corona and its polarisation |journal=Zeitschrift für Astrophysik |year=1930 |volume=1 |issue= |pages=209-36 |url=http://adsabs.harvard.edu/abs/1930ZA......1..209M |arxiv= |bibcode=1930ZA......1..209M |doi= |pmid= |accessdate=2013-07-08 }}</ref> The continuous spectrum of the corona may result from the "''[s]cattering of the photospheric light by the electrons in the corona'' ["''by emission of the corona itself due to recombinations''"] [or by] ''[t]he emission and the "scattering" in the corona ... described as one single process''".<ref name=Minnaert/> "[T]he corona is supposed to be composed of electrons and positive ions, due to ejection from the photosphere".<ref name=Minnaert/> ==Sun== {{main|Stars/Sun|Sun (star)}} [[Image:2011 03 sun030311.jpg|thumb|right|200px|This image is taken in Hα of the Sun and above showing a cloud above a sunspot. Credit: Alan Friedman.{{tlx|fairuse}}]] "Magnetic clouds represent about one third of ejecta observed by satellites at Earth. Other types of ejecta are multiple-magnetic cloud events (a single structure with multiple subclouds distinguishable)<ref>Wang, Y. M., et al., Multiple magnetic clouds in interplanetary space, Solar Physics, 211, 333-344, 2002.</ref><ref>Wang, Y. M., et al., Multiple magnetic clouds: Several examples during March - April, 2001, J. Geophys. Res., 108(A10), 1370, 2003.</ref> and complex ejecta, which can be the result of the interaction of multiple [[w:Coronal Mass Ejection|CMEs]]."<ref name=MagneticCloud>{{ cite web |title=Magnetic cloud, In: ''Wikipedia'' |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=December 5, 2012 |url=http://en.wikipedia.org/wiki/Magnetic_cloud |accessdate=2013-07-07 }}</ref> "Observations of the Hanle effect have revealed the existence of small-scale ‘hidden’ magnetic flux on the quiet Sun. The magnetic-energy density of this hidden flux is much larger than previously thought."<ref name=Stenflo>{{ cite journal |author=Jan Olof Stenflo |title=Solar physics: Hidden magnetism |journal=Nature |month=15 July |year=2004 |volume=430 |issue=6997 |pages=304-5 |url=http://www.nature.com/nature/journal/v430/n6997/full/430304a.html |arxiv= |bibcode= |doi=10.1038/430304a |pmid= |accessdate=2015-09-21 }}</ref> "Magnetic fields have occupied centre stage in solar physics for the past several decades, and have come to be regarded as the key ingredient for a unified understanding of solar phenomena. It may therefore come as a surprise that, after all these years, the magnetic-energy density in the solar atmosphere might have been seriously underestimated".<ref name=Stenflo/> {{clear}} ==Regions== {{main|Regions/Astronomy|Regions}} [[Image:LASCO C1 coronagraph of solar corona.png‎|right|thumb|200px|A picture of the solar corona is taken with the [[w:LASCO|LASCO]] C1 coronagraph. The image is color coded for the doppler shift of the FeXIV 530.8 nm line. Credit: NASA and NRL.]] The preflare solar material is observed "to be an elevated cloud of prominence-like material which is suddenly lit up by the onslaught of hard electrons accelerated in the flare; the acceleration may be inside or outside the cloud, and brightening is seen in other areas of the solar surface on the same magnetic field lines."<ref name=Zirin78>{{ cite journal |author=Harold Zirin |title=The L-alpha/H-alpha ratio in solar flares, quasars, and the chromosphere |journal=Astrophysical Journal |month=June |year=1978 |volume=222 |issue=6 |pages=L105-7 |url= |bibcode=1978ApJ...222L.105Z |doi= 10.1086/182702 |pmid= |accessdate=2011-08-01 }}</ref> "A hot coronal cloud at ''T'' ~ 10⁷ K is left behind, presumably evaporated from the original material."<ref name=Zirin78/> "[O]nce ionized, the gas is rapidly heated by Coulomb collisions to the coronal cloud temperature, but as this material peels off, a cooler hydrogen-emitting region is left."<ref name=Zirin78/> Regions which are not in [[w:coronal hole|coronal hole]]s are "called 'coronal cloud' regions after their appearance in photographs of the Sun taken in soft X-rays, which most dramatically show up coronal holes."<ref name=McWhirter>{{ cite journal |author=McWhirter, R. W. P. |author2=Kopp, R. A. |title=The energy balance in the solar atmosphere above coronal holes |journal=Royal Astronomical Society, Monthly Notices |month=September |year=1979 |volume=188 |issue=9 |pages=871-81 |url= |bibcode=1979MNRAS.188..871M |doi= |pmid= |accessdate=2011-08-01 }}</ref> These 'coronal cloud' regions are "in fact the majority of the solar surface."<ref name=McWhirter/> Lying at a level above the 10⁴ K isotherm, "the thermally conducted flux is negligible, and bounded by the magnetic surfaces between open field (coronal hole) and closed field (coronal cloud) regions."<ref name=McWhirter/> "[C]oronal cloud regions produce no solar wind," but "[s]ome of the input energy may pass out of the cloud regions into the region where the wind is accelerated, thereby contributing to this process."<ref name=McWhirter/> In the image at right the iron (Fe XIV) green line is followed by doppler imaging to show associated relative coronal plasma velocity towards (-7 km/s side) and away from (+7 km/s side) the large angle spectrometric coronagraph [[w:LASCO|LASCO]] satellite camera. {{clear}} ==Non-polar solar coronal holes== {{main|Radiation astronomy/Holes|Hole astronomy}} [[Image:Coronalhole.jpg|right|thumb|250px|Solar Disk with Coronal Hole - May 25, 2007 - by NASA STEREO (Solar TErrestrial RElations Observatory). Credit: NASA STEREO (Solar TErrestrial RElations Observatory).{{tlx|free media}}]] [[Image:417176main SDO Guide CMR Page 26 Image 0002.jpg|right|thumb|250px|A coronal hole is shown in extreme UV light. Credit: NASA.{{tlx|free media}}]] [[Image:Cor hole May-thumb-570x570-123594.jpg|thumb|right|250px|Coronal holes are areas on the Sun's corona that are darker, lower-density, and (relatively) colder than the rest of the plasma above the surface of our nearest star. Credit: NASA.{{tlx|fairuse}}]] [[Image:Two Coronal Holes on the Sun Viewed by SDO (16658479920).jpg|right|thumb|250px|NASA’s Solar Dynamics Observatory, or SDO, captured this solar image on March 16, 2015, which clearly shows two dark patches, known as coronal holes. Credit: NASA/Goddard/SDO.{{tlx|free media}}]] [[Image:Coronal Hole Front and Center.jpg|right|thumb|300px|The high-speed solar wind originating from this coronal hole, imaged hereon Oct. 10, 2015, by NASA's Solar Dynamics Observatory, created a geomagnetic storm near Earth that resulted in several nights of auroras. Credit: NASA/SDO.{{tlx|free media}}]] [[Image:PIA22197-SunFormsQuestionMark-20171222.jpg|right|thumb|250px|NASA's Solar Dynamics Observatory observed an elongated coronal hole (the darker area near the center) seeming to shape itself into a single, recognizable question mark over the period of one day (Dec. 21-22, 2017). Credit: .{{tlx|free media}}]] "The striking absence of green emission above both polar regions at activity minimum led Waldmeier (1957) to use the German term 'Koronalöcher', ie, coronal holes."<ref name=Schwenn>{{ cite journal |author=R. Schwenn |author2=B. Inhester |author3=S. P. Plunkett |author4=A. Epple |author5=B. Podlipnik |author6=D. K. Bedford |author7=C. J. Eyles |author8=G. M. Simnett |author9=S. J. Tappin |author10=M. V. Bout |display-authors=etal |title=First View of the Extended Green-Line Emission Corona At Solar Activity Minimum Using the Lasco-C1 Coronagraph on Soho |journal=Solar Physics |month=October |year=1997 |volume=175 |issue=2 |pages=667-84 |url=http://www.springerlink.com/index/R10HN0R60R081237.pdf |arxiv= |bibcode= |doi=10.1023/A:1004948913883 |pmid= |accessdate=2012-02-17 }}</ref> "Here we restrict ourselves to a qualitative study of large scale structures of the green emission line corona."<ref name=Schwenn/> The image descriptions that follow emphasize various non-polar holes. For the coronal hole from 25 May 2007: the image of the solar coronal cloud at top right shows both of the polar coronal holes and one apparently isolated, non-polar coronal hole. Third image down on the right: "Coronal holes are areas on the sun's corona that are darker, lower-density, and (relatively) colder than the rest of the plasma on the surface of our nearest star. They're the source of the kind of solar wind gusts that carry solar particles out to our magnetosphere and beyond, causing auroras (and, less awesomely, geomagnetic storms) here on Earth."<ref name=Garber>{{ cite book |author=Megan Garber |title=No Big Deal, Just a Giant Hole in the Sun |publisher=The Atlantic |location= |date=5 June 2013 |url=http://www.theatlantic.com/technology/archive/2013/06/no-big-deal-just-a-giant-hole-in-the-sun/276564/ |accessdate=2015-05-18 }}</ref> "When coronal holes are captured in extreme ultraviolet light images, they reveal themselves as dark spots that appear, to human eyes, to be plasma voids."<ref name=Garber/> "Well, last week -- between May 28 and 31 -- one of those coronal holes rotated toward Earth. It was a big one: "one of the largest," NASA says, "we have seen in a year or more." And the Solar Dynamics Observatory's Atmospheric Imaging Assembly, fortunately, got a shot of the thing. Above, via a combination of three wavelengths of UV light, is an image of the hole. It's pretty gorgeous, as holes go."<ref name=Garber/> "And while coronal holes are more likely to affect Earth after they've rotated more than halfway around the visible hemisphere of the sun -- which was the case with this guy -- the most this one would have done, astronomers say, was to generate some aurora."<ref name=Garber/> The image third down on the right shows one of the largest non-polar coronal holes ever observed in May, apparently in 2013. For the fourth image down on the right: "NASA’s Solar Dynamics Observatory, or SDO, captured this solar image on March 16, 2015, which clearly shows two dark patches, known as coronal holes. The larger coronal hole of the two, near the southern pole, covers an estimated 6- to 8-percent of the total solar surface. While that may not sound significant, it is one of the largest polar holes scientists have observed in decades. The smaller coronal hole, towards the opposite pole, is long and narrow. It covers about 3.8 billion square miles on the sun - only about 0.16-percent of the solar surface."<ref name=Goddard>{{ cite book |author=NASA/Goddard/SDO |title=Two Coronal Holes on the Sun Viewed by SDO |publisher=Goddard Space Flight Center |location=Greenbelt, Maryland USA |date=17 March 2015 |editor= |pages=1 |url=https://www.flickr.com/people/24662369@N07 |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2018-02-07 }}</ref> Per the fifth image down on the right: "The dark area across the top of the sun in this image is a coronal hole, a region on the sun where the magnetic field is open to inter planetary space, sending coronal material speeding out in what is called a high-speed solar wind stream. The high-speed solar wind originating from this coronal hole, imaged hereon Oct. 10, 2015, by NASA's Solar Dynamics Observatory, created a geomagnetic storm near Earth that resulted in several nights of auroras. This image was taken in wavelengths of 193 Angstroms, which is invisible to our eyes and is typically colorized in bronze."<ref name=NASA>{{ cite book |author=NASA/SDO |title=Coronal Hole Front and Center |publisher=GSFC |location=Greenbelt, Maryland USA |date=15 October 2015 |editor= |pages=1 |url=https://www.nasa.gov/image-feature/goddard/coronal-hole-front-and-center |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2018-02-07 }}</ref> Relative to the sixth image down on the right: "Oddly enough, an elongated coronal hole (the darker area near the center) seems to shape itself into a single, recognizable question mark over the period of one day (Dec. 21-22, 2017). Coronal holes are areas of open magnetic field that appear darker in extreme ultraviolet light, as is seen here. These holes are the source of streaming plasma that we call solar wind."<ref name=Dynamics>{{ cite book |author=NASA/GSFC/Solar Dynamics Observatory |title=PIA22197: The Sun Forms a Question |publisher=GSFC |location=Greenbelt, Maryland USA |date=29 December 2017 |editor= |pages=1 |url=https://photojournal.jpl.nasa.gov/jpeg/PIA22197.jpg |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2018-02-07 }}</ref> While the hole is connected to the polar coronal hole it does extend to mid-latitudes. {{clear}} ==Mercury== {{main|Wanderers/Mercury|Mercury}} [[Image:Mercury Sodium tail (PIA11076).jpg|thumb|right|200px|The sodium tail of Mercury is mapped out during the MESSENGER's first flyby on January 14, 2008. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.]] [[Image:Ca and Mg tail of Mercury (PIA12366).jpg|thumb|left|200px|Mercury's calcium and magnesium tail is mapped out during the MESSENGER's third flyby on September 29, 2009. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.]] "MOST current literature on solar activity assumes that the planets do not affect it, and that conditions internal to the Sun are primarily responsible for the solar cycle. Bigg¹, however, has shown that the period of Mercury's orbit appears in the sunspot data, and that the influence of Mercury depends on the phases of Venus, Earth, and Jupiter."<ref name=Wood>{{ cite journal |author=K. D. Wood |title=Physical Sciences: Sunspots and Planets |journal=Nature |month=November 10, |year=1972 |volume=240 |issue=5376 |pages=91-3 |url=http://www.nature.com/nature/journal/v240/n5376/abs/240091a0.html |arxiv= |bibcode=1972Natur.240...91W |doi=10.1038/240091a0 |pmid= |accessdate=2013-07-07 }}</ref> "Some observations show that Mercury is surrounded by a hot corona of calcium atoms with temperature between 12,000 and 20,000&nbsp;K.<ref name=Killen>{{ cite journal |author=Rosemary Killen |author2=Gabrielle Cremonese |author3=Helmut Lammer |display-authors=etal |title=Processes that Promote and Deplete the Exosphere of Mercury |year=2007 |journal=Space Science Reviews |volume=132 |issue=2-4 |pages=433–509 |doi=10.1007/s11214-007-9232-0 |bibcode=2007SSRv..132..433K }}</ref>"<ref name=AtmosphereofMercury>{{ cite web |title=Atmosphere of Mercury, In: ''Wikipedia'' |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=May 29, 2013 |url=http://en.wikipedia.org/wiki/Atmosphere_of_Mercury |accessdate=2013-07-09 }}</ref> At right is a diagram of Mercury's sodium tail. "As the MESSENGER spacecraft approached Mercury, the UVVS field of view was scanned across the planet's exospheric "tail," which is produced by the solar wind pushing Mercury's exosphere (the planet's extremely thin atmosphere) outward. This figure, recently published in Science magazine, shows a map of the distribution of sodium atoms as they stream away from the planet (see PIA10396); red and yellow colors represent a higher abundance of sodium than darker shades of blue and purple, as shown in the colored scale bar, which gives the brightness intensity in units of kiloRayleighs. The escaping atoms eventually form a comet-like tail that extends in the direction opposite that of the Sun for many planetary radii. The small squares outlined in black correspond to individual measurements that were used to create the full map. These measurements are the highest-spatial-resolution observations ever made of Mercury's tail. In less than six weeks, on October 6, 2008, similar measurements will be made during MESSENGER's second flyby of Mercury. Comparing the measurements from the two flybys will provide an unprecedented look at how Mercury's dynamic exosphere and tail vary with time."<ref name=Lavoie2008>{{ cite web |author=Sue Lavoie |title=PIA11076: Exploring Mercury's "Tail" |publisher=NASA/JPL |location=Pasadena, California USA |date=August 26, 2008 |url=http://photojournal.jpl.nasa.gov/catalog/PIA11076 |accessdate=2013-07-09 }}</ref> At left are two diagrams showing the approximate distribution of calcium and magnesium in Mercury's tail. "These figures show observations of calcium and magnesium in Mercury's neutral tail during the third MESSENGER Mercury flyby. The distribution of neutral calcium in the tail appears to be centered near the equatorial plane and the emission rapidly decreases to the north and south as well as in the anti-sunward direction. In contrast, the distribution of magnesium in the tail exhibits several strong peaks in emission and a slower decrease in the north, south, and anti-sunward directions. These distributions are similar to those seen during the second flyby, but the densities were higher during the third flyby, a different "seasonal" variation than for sodium. Studying the changes of the "seasons" for a range of species during MESSENGER's orbital mission phase will be key to quantifying the processes that generate and maintain the exosphere and transport volatile material within the Mercury environment."<ref name=Lavoie2009>{{ cite web |author=Sue Lavoie |title=PIA12366: Calcium and Magnesium in Mercury's Exosphere |publisher=NASA/JPL |location=Pasadena, California USA |date=November 5, 2009 |url=http://photojournal.jpl.nasa.gov/catalog/PIA12366 |accessdate=2013-07-09 }}</ref> {{clear}} ==Venus== {{main|Wanderers/Venus|Venus}} "A non-thermal, or “hot”, Venus corona of H atoms has been observed by Mariners 5 and 10 and Venera 9."<ref name=Kumar>{{ cite journal |author=S. Kumar |author2=D.M. Hunten |author3=A.L. Broadfoot |title=Non-thermal hydrogen in the Venus exosphere: The ionospheric source and the hydrogen budget |journal=Planetary and Space Science |month=November |year=1978 |volume=26 |issue=11 |pages=1063-75 |url=http://www.sciencedirect.com/science/article/pii/0032063378900296 |arxiv= |bibcode= |doi=10.1016/0032-0633(78)90029-6 |pmid= |accessdate=2013-07-10 }}</ref> "After more than two years in orbit still no Venus Express observations were published concerning the hot oxygen corona of Venus which could verify the corresponding controversial observations of Venera 11 and PVO, three decades ago."<ref name=Lichtenegger>{{ cite journal |author=H. I. M. Lichtenegger |author2=H. Gröller |author3=H Lammer |author4=Yu. N. Kulikov |author5=V. I. Shematovich |title=On the elusive hot oxygen corona of Venus |journal=Geophysical Research Letters |month=May |year=2009 |volume=36 |issue=10 |pages= |url=http://onlinelibrary.wiley.com/doi/10.1029/2009GL037575/full |arxiv= |bibcode= |doi=10.1029/2009GL037575 |pmid= |accessdate=2013-07-10 }}</ref> "Venus has a hot oxygen corona in addition to its hydrogen corona (Nagy et al., 1981) and charge-exchange between protons and oxygen is accidentally resonant."<ref name=Russell>{{ cite journal |author=C. T. Russell |author2=T. I. Gombosi |author3=M. Horanyi |author4=T. E. Cravens |author5=A. F. Nagy |title=Charge‐exchange in the magnetosheaths of Venus and Mars: A comparison |journal=Geophysical Research Letters |month=February |year=1983 |volume=10 |issue=2 |pages=163-4 |url=http://onlinelibrary.wiley.com/doi/10.1029/GL010i002p00163/full |arxiv= |bibcode= |doi=10.1029/GL010i002p00163 |pmid= |accessdate=2013-07-10 }}</ref> ==Earth== [[Image:Earthxray polar.jpg|thumb|right|200px|This image is a composite of the first picture of the Earth in X-rays over a diagram of the Earth below. Credit: NASA, Ruth Netting.]] At right is a composite image which contains the first picture of the Earth in X-rays, taken in March, 1996, with the orbiting [[w:Polar (satellite)|Polar]] satellite. The area of brightest X-ray emission is red. Energetic charged particles from the Sun energize electrons in the Earth's magnetosphere. These electrons move along the Earth's magnetic field and eventually strike the ionosphere, causing the X-ray emission. Lightning strikes or bolts across the sky also emit X-rays.<ref name=Newitz>Newitz, A. (2007) ''Educated Destruction 101''. Popular Science magazine, September. pg. 61.</ref> {{clear}} ==Mars== {{main|Wanderers/Mars|Mars}} "Both Earth and Mars have extensive coronae, whereas the Venus corona manifests itself almost entirely within two planetary radii. The Mars corona is relatively thin and exhibits a slight brightening at the dark limb."<ref name=Anderson>{{ cite journal |author=Donald E. Anderson Jr., Charles W. Hord |title=Multidimensional radiative transfer: Applications to planetary coronae |journal=Planetary and Space Science |month=June |year=1977 |volume=25 |issue=6 |pages=563-71 |url=http://www.sciencedirect.com/science/article/pii/0032063377900630 |arxiv= |bibcode= |doi=10.1016/0032-0633(77)90063-0 |pmid= |accessdate=2013-07-10 }}</ref> ==Comets== [[Image:Comet Lulin Jan. 28-2009 Swift gamma.jpg|thumb|right|200px|This is a composite image of Comet Lulin. X-ray emission is in red. Credit: .]] [[Image:Lovejoy C-2011 W3 imaged by STEREO-A EUVI.gif|thumb|left|Comet Lovejoy is detected in STEREO/SECCHI's EUVI-A imager's 17.1-nm wavelength. Credit: STEREO/SECCHI image courtesy NASA/NRL.]] "[[w:Comet Lulin|Comet Lulin]] was passing through the constellation Libra when Swift imaged it on January 28, 2009. The image at right merges data acquired by [[w:Swift|Swift]]'s Ultraviolet/Optical Telescope (blue and green) and X-Ray Telescope (red). At the time of the observation, the comet was 99.5 million miles from Earth and 115.3 million miles from the Sun."<ref name=AstrophysicalXraysource/> "NASA's Swift Gamma-ray Explorer satellite was monitoring Comet Lulin as it closed to 63 Gm of Earth. For the first time, astronomers can see simultaneous UV and X-ray images of a comet. "The solar wind -- a fast-moving stream of particles from the sun -- interacts with the comet's broader cloud of atoms. This causes the solar wind to light up with X-rays, and that's what Swift's XRT sees", said Stefan Immler, of the Goddard Space Flight Center. This interaction, called charge exchange, results in X-rays from most comets when they pass within about three times Earth's distance from the sun. Because Lulin is so active, its atomic cloud is especially dense. As a result, the X-ray-emitting region extends far sunward of the comet.<ref name=Reddy>{{ cite web |author=F Reddy |title=NASA's Swift Spies Comet Lulin |url=http://www.nasa.gov/mission_pages/swift/bursts/lulin.html }}</ref>"<ref name=AstrophysicalXraysource/> At left is Comet Lovejoy as detected in STEREO/SECCHI's EUVI-A imager's 17.1-nm wavelength. "The comet is clearly visible racing away from the Sun, leaving a wiggly-tail in its wake! Why the wiggles? We're not sure -- we need to start studying that when we get all of the spacecraft data from STEREO-B this weekend. However, we think there may some kind of helical motion going on, or perhaps there's a projection affect and we're seeing tail material magnetically "clinging" to coronal loops and moving with them. There are other possibilities too, though, and we will certainly investigate those! We should have equivalent images from the STEREO-A spacecraft which we will also get this weekend. When we pair these together, and throw in the SDO images too, we should be able to get an incredibly unique 3-D picture of how this comet is reacting the intense coronal heat and magnetic loops."<ref name=Battams>{{ cite web |author=Karl Battams |title=The Great "Birthday Comet" of 2011, Chapter 2: Survival |publisher=Naval Research Laboratory |location=Washington, DC, USA |date=December 2, 2011 |url=http://sungrazer.nrl.navy.mil/index.php?p=news/birthday_comet |accessdate=2013-07-07 }}</ref> {{clear}} ==Jupiter== {{main|Wanderers/Jupiter|Jupiter}} [[Image:Jupiter X-ray Aurora Chandra.jpg|thumb|right|200px|This image of Jupiter shows concentrations of auroral X-rays near the north and south magnetic poles. The Chandra X-ray Observatory accumulated X-ray counts from Jupiter for its entire 10-hour rotation on December 18, 2000. Credit: NASA/CXC/SWRI/G.R.Gladstone et al.]] "Because of an eccentricity of 0.048, the distance from Jupiter and the Sun varies by 75 million km between perihelion and aphelion, or the nearest and most distant points of the planet along the orbital path respectively."<ref name=Jupiter>{{ cite web |title=Jupiter, In: ''Wikipedia'' |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=July 5, 2013 |url=http://en.wikipedia.org/wiki/Jupiter |accessdate=2013-07-07 }}</ref> "Favorable oppositions occur when Jupiter is passing through [[w:Apsis|perihelion]], an event that occurs once per orbit. As Jupiter approached perihelion in March 2011, there was a favorable opposition in September 2010.<ref name=jup2010>{{cite web |author=Horizons output |url=http://home.surewest.net/kheider/astro/jup2010.txt |title=Favorable Appearances by Jupiter |accessdate=2008-01-02}} ([http://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=mb&sstr=599 Horizons])</ref>"<ref name=Jupiter/> It's orbital period is 4,332.59 d (11.8618 y). "It is shown that starting with the alignment of Venus with Jupiter at perihelion position, these two planets will perfectly align at Jupiter's perihelion after every 23.7 years".<ref name=Verma>{{ cite book |author=S.D. Verma |title=Influence of Planetary Motion and Radial Alignment of Planets on Sun, In: ''Space Dynamics and Celestial Mechanics'' |publisher=Springer Netherlands |location= |year=1986 |editor=K. B. Bhatnagar |volume=127 |issue= |pages=143-54 |url=http://link.springer.com/chapter/10.1007/978-94-009-4732-0_13 |arxiv= |bibcode= |doi=10.1007/978-94-009-4732-0_13 |pmid= |isbn=978-94-010-8603-5 |accessdate=2013-07-07 }}</ref> "The tidal forces hypothesis for solar cycles has been proposed by Wood (1972) and others. Table 2 below shows the relative tidal forces of the planets on the sun. Jupiter, Venus, Earth and Mercury are called the "tidal planets" because they are the most significant. According to Wood, the especially good alignments of J-V-E with the sun which occur about every 11 years are the cause of the sunspot cycle. He has shown that the sunspot cycle is synchronous with the alignments, and J. Schove's data for 1500 year of sunspot maxima supports the 11.07 year J-V-E period average."<ref name=Tomes/> "Both the 11.86 year Jupiter tropical period (time between perihelion's or closest approaches to the sun and the 9.93 year J-S alignment periods are found in sunspot spectral analysis. Unfortunately direct calculations of the tidal forces of all planets does not support the occurrence of the dominant 11.07 year cycle. Instead, the 11.86 year period of Jupiter's perihelion dominates the results. This has caused problems for several researchers in this field."<ref name=Tomes>{{ cite journal |author=Ray Tomes |title=Towards a Unified Theory of Cycles |publisher=Cycles Research Institute |location= |month=February |year=1990 |editor= |volume= |issue= |pages=21 |url=http://cyclesresearchinstitute.org/cycles-general/tomes_unified_cycles.pdf |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2013-07-07 }}</ref> The "image of Jupiter [at right] shows concentrations of auroral X-rays near the north and south magnetic poles."<ref name=Gladstone>{{ cite web |author=NASA/CXC/SWRI/G.R.Gladstone |display-authors=etal |title=Jupiter Hot Spot Makes Trouble For Theory |publisher=Harvard-Smithsonian Center for Astrophysics |location=Cambridge, Massachusetts |date=February 27, 2002 |url=http://chandra.harvard.edu/photo/2002/0001/ |accessdate=2012-07-11 }}</ref> The Chandra X-ray Observatory accumulated X-ray counts from Jupiter for its entire 10-hour rotation on December 18, 2000. The coronal cloud around Jupiter is exactly opposite to that around the Sun. At the Sun there are polar coronal holes, whereas at Jupiter the coronal cloud is most prevalent over the magnetic poles. {{clear}} ==Saturn== {{main|Wanderers/Saturn|Saturn}} "Saturn's corona plays a major role in supplying hydrogen to the circumplanetary volume."<ref name=Smyth>{{ cite web |author=W.H. Smyth, M.R. Combi |title=Extended atmospheres of outer planet satellites and comets. Interim report, 15 June-14 September 1987 |publisher= |location= |date=November 1, 1987 |pages=122 |url=http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=5275119 |accessdate=2013-07-10 }}</ref> "This cloud probably connects to the extended hydrogen corona of Saturn (Broadfoot et al., 1981; Shemansky and Hall, 1992) and to hydrogen-rich icy surfaces in the inner magnetosphere."<ref name=Young>{{ cite journal |author=D. T. Young |author2=J. J. Berthelier |author3=M. Blanc |author4=J. L. Burch |author5=A. J. Coates |author6=R. Goldstein |author7=M. Grande |author8=T. W. Hill |author9=R. E. Johnson |author10=V. Kelha |author11=D. J. Mccomas |author12=E. C. Sittler |author13=K. R. Svenes |author14=K. Szegö |author15=P. Tanskanen |author16=K. Ahola |author17=D. Anderson |author18=S. Bakshi |author19=R. A. Baragiola |author20=B. L. Barraclough |author21=R. K. Black |author22=S. Bolton |author23=T. Booker |author24=R. Bowman |author25=P. Casey |author26=F. J. Crary |author27=D. Delapp |author28=G. Dirks |author29=N. Eaker |author30=H. Funsten |author31=J. D. Furman |author32=J. T. Gosling |author33=H. Hannula |author34=C. Holmlund |author35=H. Huomo |author36=J. M. Illiano |author37=P. Jensen |author38=M. A. Johnson |author39=D. R. Linder |author40=T. Luntama |author41=S. Maurice |author42=K. P. Mccabe |author43=K. Mursula |author44=B. T. Narheim |author45=J. E. Nordholt |author46=A. Preece |author47=J. Rudzki |author48=A. Ruitberg |author49=K. Smith |author50=S. Szalai |author51=M. F. Thomsen |author52=K. Viherkanto |author53=J. Vilppola |author54=T. Vollmer |author55=T. E. Wahl |author56=M. Wüest |author57=T. Ylikorpi |author58=C. Zinsmeyer |title=Cassini plasma spectrometer investigation |journal=Space Science Reviews |month=September |year=2004 |volume=114 |issue=1-4 |pages=1-112 |url=http://link.springer.com/article/10.1007/s11214-004-1406-4 |arxiv= |bibcode= |doi=10.1007/s11214-004-1406-4 |pmid= |accessdate=2013-07-10 }}</ref> ==Uranus== {{main|Wanderers/Uranus|Uranus}} "The upper part of the thermosphere, where the mean free path of the molecules exceeds the scale height, [The scale height ''sh'' is defined as {{nowrap|1=''sh'' = ''RT''/(''Mg_j'')}}, where {{nowrap|1=''R'' = 8.31 J/mol/K}} is the gas constant, {{nowrap|1=''M'' ≈ 0.0023 kg/mol}} is the average molar mass in the Uranian atmosphere,<ref name=Lunine>{{cite journal | doi = 10.1146/annurev.aa.31.090193.001245 | last = Lunine | first = Jonathan I. | year = 1993 | month = September | title = The Atmospheres of Uranus and Neptune | journal = Annual Review of Astronomy and Astrophysics | volume = 31 | pages = 217–263 | bibcode = 1993ARA&A..31..217L }}</ref> ''T'' is temperature and {{nowrap|1=g_j ≈ 8.9 m/s²}} is the gravitational acceleration at the surface of [[Uranus]]. As the temperature varies from 53&nbsp;K in the tropopause up to 800&nbsp;K in the thermosphere, the scale height changes from 20 to 400&nbsp;km.] is called the [[exosphere]].<ref name=Herbert>{{cite journal | doi = 10.1029/96JA00427 | last1 = Herbert | first1 = Floyd | last2 = Hall | first2 = Doyle T. | year = 1996 | month = May | title = Atomic hydrogen corona of Uranus | journal = Journal of Geophysical Research | pages = 10,877–10,885 | volume = 101 | issue = A5 | bibcode = 1996JGR...10110877H }}</ref> The lower boundary of the Uranian exosphere, the exobase, is located at a height of about 6,500&nbsp;km, or 1/4 of the planetary radius, above the surface.<ref name=Herbert/> The exosphere is unusually extended, reaching as far as several Uranian radii from the planet.<ref name=Herbert/><ref name=Herbert1999>{{cite journal | doi = 10.1016/S0032-0633(98)00142-1 | last1 = Herbert | first1 = Floyd | last2 = Sandel | first2 = Bill R. | year = 1999 | month = August–September | title = Ultraviolet observations of Uranus and Neptune | journal = Planetary and Space Science | volume = 47 | issue = 8–9 | pages = 1,119–1,139 | bibcode = 1999P&SS...47.1119H | ref = harv }}</ref> It is made mainly of hydrogen atoms and is often called the hydrogen corona of Uranus.<ref name=Herbert1987>{{cite journal | doi = 10.1029/JA092iA13p15093 | last1 = Herbert | first1 = Floyd | last2 = Sandel | first2 = B. R. | last3 = Yelle | first3 = R. V. | last4 = Holberg | first4 = J. B. | last5 = Broadfoot | first5 = A. L. | last6 = Shemansky | first6 = D. E. | last7 = Atreya | first7 = S. K. | last8 = Romani | first8 = P. N. | date = December 30, 1987 | title = The Upper Atmosphere of Uranus: EUV Occultations Observed by Voyager 2 | journal = Journal of Geophysical Research | volume = 92 | issue = A13 | pages = 15,093–15,109 | url = http://www-personal.umich.edu/~atreya/Articles/1987_Upper_Atm_Uranus.pdf | bibcode = 1987JGR....9215093H }}</ref> The high temperature and relatively high pressure at the base of the thermosphere explain in part why Uranus's exosphere is so vast. The corona contains a significant population of supra-thermal (energy of up to 2&nbsp;eV) hydrogen atoms. Their origin is unclear, but they may be produced by the same mechanism that heats the thermosphere.<ref name=Herbert/><ref name=Herbert1999/> The number density of atomic hydrogen in the corona falls slowly with the distance from the planet, remaining as high a few hundred atoms per cm³ at a few radii from Uranus.<ref name=Herbert/> The effects of this bloated exosphere include a drag on small particles orbiting Uranus, causing a general depletion of dust in the Uranian rings. The infalling dust in turn contaminates the upper atmosphere of the planet.<ref name=Herbert1987/>"<ref name=AtmosphereofUranus>{{ cite web |title=Atmosphere of Uranus, In: ''Wikipedia'' |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=May 17, 2013 |url=http://en.wikipedia.org/wiki/Atmosphere_of_Uranus |accessdate=2013-07-09 }}</ref> ==Epsilon Eridani== {{main|Stars/Epsilon Eridani|Epsilon Eridani}} "Epsilon Eridani has a higher level of magnetic activity than the Sun, and hence demonstrates increased activity in the outer parts of the star's atmosphere: the [[chromosphere]] and corona. The average magnetic field strength of this star across the entire surface is {{nowrap|(1.65 ± 0.30) × 10⁻² T}},<ref name=aaa318_429>{{ cite journal | author=I. Rüedi |author2=S. K. Solanki |author3=G. Mathys |author4=S. H. Saar | title=Magnetic field measurements on moderately active cool dwarfs | journal=Astronomy and Astrophysics | volume=318 | pages=429–42 | month=February | year=1997 | bibcode=1997A&A...318..429R }}</ref> which is more than forty times greater than the {{nowrap|(5–40) × 10⁻⁵ T}} magnetic field strength in the Sun's photosphere.<ref name=apj591_2_1248>{{ cite journal | author=Y.-M. Wang, N. R. Sheeley Jr. | title=Modeling the Sun's Large-Scale Magnetic Field during the Maunder Minimum | journal=The Astrophysical Journal | volume=591 | issue=2 | pages=1248&ndash;56 | month=July | year=2003 | doi=10.1086/375449 | bibcode=2003ApJ...591.1248W }}</ref>"<ref name=EpsilonEridani>{{ cite web |title=Epsilon Eridani, In: ''Wikipedia'' |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=May 22, 2013 |url=http://en.wikipedia.org/wiki/Epsilon_Eridani |accessdate=2013-07-09 }}</ref> "The X-ray luminosity of Epsilon Eridani is about {{nowrap|2 × 10²⁸ [[w:Erg|erg]]s/s}} ({{nowrap|2 × 10²¹ [[w:Watt|W]]}}). It is brighter in X-ray emission than the Sun at [[w:Solar cycle|peak activity]]. The source for this strong X-ray emission is the star's hot corona.<ref name=apj243_234>{{ cite journal | author=H. M. Johnson | title=An X-ray sampling of nearby stars | journal=The Astrophysical Journal | volume=243 | date=January 1, 1981 | pages=234–43 | doi=10.1086/158589 | bibcode=1981ApJ...243..234J }}</ref><ref name=apj457_882>{{ cite journal | author=J. H. M. M. Schmitt |author2=J. J. Drake |author3=R. A. Stern |author4=B. M. Haisch | title=The extreme-ultraviolet spectrum of the nearby K Dwarf ε Eridani | journal=Astrophysical Journal | volume=457 | page=882 | month=February | year=1996 | doi=10.1086/176783 | bibcode=1996ApJ...457..882S }}</ref> Epsilon Eridani's corona appears larger and hotter than the Sun's, with a temperature of {{nowrap|3.4 × 10⁶ K}} as measured from observation of the corona's ultraviolet and X-ray emission.<ref name=mnras385_4_1691/>"<ref name=EpsilonEridani/> "The [[w:stellar wind|stellar wind]] emitted by Epsilon Eridani expands until it collides with the surrounding [[interstellar medium]] of sparse gas and dust, resulting in a bubble of heated hydrogen gas. The [[w:absorption spectrum|absorption spectrum]] from this gas has been measured with the [[w:Hubble Space Telescope|Hubble Space Telescope]], allowing the properties of the stellar wind to be estimated.<ref name=mnras385_4_1691>{{ cite journal | author=J.-U. Ness, C. Jordan | title=The corona and upper transition region of ε Eridani | journal=Monthly Notices of the Royal Astronomical Society | volume=385 | issue=4 | pages=1691–708 | month=April | year=2008 | doi=10.1111/j.1365-2966.2007.12757.x | bibcode=2008MNRAS.385.1691N | arxiv=0711.3805 }}</ref> Epsilon Eridani's hot corona results in a mass loss rate from the star's stellar wind that is 30 times higher than the Sun's. This wind is generating an [[w:Stellar wind bubble|astrosphere]] (the equivalent of the [[w:heliosphere|heliosphere]] that surrounds the Sun) that spans about 8,000&nbsp;AU and contains a [[w:bow shock|bow shock]] that lies 1,600&nbsp;AU from the star. At its estimated distance from Earth, this astrosphere spans 42&nbsp;arcminutes, which is wider than the apparent size of the full Moon.<ref name=apj574_1>{{ cite journal | author=Brian E. Wood |author2=Hans-Reinhard Müller |author3=Gary P. Zank |author4=Jeffrey L. Linsky | title=Measured mass-loss rates of solar-like stars as a function of age and activity | journal=The Astrophysical Journal | month=July | year=2002 | volume=574 | issue=1 | pages=1–2 | doi=10.1086/340797 | bibcode=2002ApJ...574..412W | arxiv=astro-ph/0203437 }} See p. 10.</ref>"<ref name=EpsilonEridani/> ==Gliese 176== {{main|Stars/Gliese 176|Gliese 176}} "The corona of this star has a moderate emission of X-rays at 3 × 10²⁷ erg s^–1. This indicates the star is active, and may exhibit starspots and flares much like the Sun. This is considered normal for a main-sequence star of spectral class M."<ref name=Gliese176>{{ cite web |title=Gliese 176, In: ''Wikipedia'' |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=June 12, 2013 |url=http://en.wikipedia.org/wiki/Gliese_176 |accessdate=2013-07-10 }}</ref> ==Local hot bubbles== {{main|Plasmas/Plasma objects/Bubbles/Locals/Hot|Local hot bubbles}} [[Image:Local_bubble.jpg|thumb|right|200px|The Local Hot Bubble is hot X-ray emitting gas within the Local Bubble pictured as an artist's impression. Credit: NASA.]] The 'local hot bubble' is a "hot X-ray emitting plasma within the local environment of the Sun."<ref name=Kappes>{{ cite journal |author=M. Kappes |author2=J. Kerp |author3=P. Richter |title=The composition of the interstellar medium towards the Lockman Hole H I, UV and X-ray observations |journal=Astronomy and Astrophysics |month=July |year=2003 |volume=405 |issue=7 |pages=607-16 |url= |arxiv= |bibcode=2003A&A...405..607K |doi=10.1051/0004-6361:20030610 |pmid= |accessdate=2012-01-19 }}</ref> "This coronal gas fills the irregularly shaped local void of matter (McCammon & Sanders 1990) - frequently called the Local Hot Bubble (LHB)."<ref name=Kappes/> '''Def.''' a "hot X-ray emitting plasma within the local environment of the Sun"<ref name=Kappes/> is called the '''Local Hot Bubble'''. "The [X-ray] intensity of the [Local Hot Bubble] LHB varies across the entire sky:"<ref name=Kerp>{{ cite journal |author=J. Kerp |author2=W. B. Burton |author3=R. Egger |author4=M.J. Freyberg |author5=Dap Hartmann |author6=P.M.W. Kalberla |author7=U. Mebold |author8=J. Pietz |title=A search for soft X-ray emission associated with prominent high-velocity-cloud complexes |journal=Astronomy and Astrophysics |month=February |year=1999 |volume=342 |issue=02 |pages=213-32 |url=http://arxiv.org/abs/astro-ph/9810307 |arxiv=astro-ph/9810307 |bibcode=1999A&A...342..213K |doi= |pmid= |accessdate=2013-07-11 }}</ref> : ''I''_LHB = (2.5-8.2) x 10^-4 cts s^-1 arcmin^-2 (Snowden et al. 1998). The galactic X-ray background is produced largely by emission from the Local Hot Bubble which is within 100 parsecs of the Sun. The Local Hot Bubble is within the [[w:Local Bubble|Local Bubble]]. ==White dwarfs== {{main|Stars/Dwarfs/Whites|White dwarfs}} "The white dwarf is surrounded by an expanding shell of gas in an object known as a planetary nebula. [[w:Planetary nebulae|Planetary nebulae]] seem to mark the transition of a medium mass star from [[w:red giant|red giant]] to white dwarf. X-ray images reveal clouds of multimillion degree gas that have been compressed and heated by the fast stellar wind."<ref name=AstrophysicalXraysource/> ==Chamaeleon I dark clouds== {{main|Radiation astronomy/Meteors/Clouds|Chamaeleon I dark clouds}} [[Image:Chamaeleon_I_cloud.png|thumb|right|200px|A [[w:ROSAT|ROSAT]] false-color image in X-rays between 500 eV and 1.1 keV shows the Chamaeleon I dark cloud. The contours are 100 µm emission from dust measured by the IRAS satellite. Credit: Dr. David Burrows and then graduate student Jeff Mendenhall of the Penn State Department of Astronomy & Astrophysics, and is based on a mosaic of images collected by Dr. Burrows and by Dr. Eric Feigelson of Penn State using the US/German ROSAT satellite.]] "The Chamaeleon I (Cha I) cloud is a coronal cloud and one of the nearest active [[star-forming region]]s at ~160 pc.<ref name=Feigelson2004/> It is relatively isolated from other star-forming clouds, so it is unlikely that older pre-main sequence (PMS) stars have drifted into the field.<ref name=Feigelson2004>{{ cite journal |doi=10.1086/423613 |author=Feigelson ED, Lawson WA |title=An X-ray census of young stars in the Chamaeleon I North Cloud |journal=The Astrophysical Journal |month=October |year=2004 |volume=614 |issue=10 |pages=267–83 |url=http://www.iop.org/EJ/article/0004-637X/614/1/267/60370.web.pdf?request-id=63d27661-73a2-47f1-8b87-17c4df8c7e65 |bibcode=2004ApJ...614..267F |arxiv = astro-ph/0406529 }}</ref> The total stellar population is 200-300.<ref name=Feigelson2004/> The Cha I cloud is further divided into the North cloud or region and South cloud or main cloud."<ref name=AstrophysicalXraysource/>{{clear}} ==Chamaeleon II dark clouds== {{main|Radiation astronomy/Meteors/Clouds|Chamaeleon II dark clouds}} "The Chamaeleon II dark cloud contains some 40 X-ray sources.<ref name=Alcala2000>{{ cite journal |author=Alcalá JM |author2=Covino E |author3=Sterzik MF |author4=Schmitt JHMM |author5=Krautter J |author6=Neuhäuser R |title=A ROSAT pointed observation of the Chamaeleon II dark cloud |journal=Astronomy & Astrophysics |month=March |year=2000 |volume=355 |issue=3 |pages=629–38 |bibcode=2000A&A...355..629A }}</ref> Observation in Chamaeleon II was carried out from September 10 to 17, 1993.<ref name=Alcala2000/> Source RXJ 1301.9-7706, a new WTTS candidate of [[w:spectral type|spectral type]] K1, is closest to 4U 1302-77.<ref name=Alcala2000/>"<ref name=AstrophysicalXraysource/> ==Chamaeleon III dark clouds== {{main|Radiation astronomy/Meteors/Clouds|Chamaeleon III dark clouds}} "Chamaeleon III appears to be devoid of current star-formation activity."<ref name=Yamauchi>{{ cite journal |author=Yamauchi S |author2=Hamaguchi K |author3=Koyama K |author4=Murakami H |title=ASCA Observations of the Chamaeleon II Dark Cloud |journal=Publ Astron Soc Japan |month=October |year=1998 |volume=50 |issue=10 |pages=465–74 |bibcode=1998PASJ...50..465Y }}</ref> "HD 104237 ([[w:spectral type|spectral type]] A4e) observed by [the [[w:Advanced Satellite for Cosmology and Astrophysics|Advanced Satellite for Cosmology and Astrophysics]] (ASCA)], located in the Chamaeleon III dark cloud, is the brightest Herbig Ae/Be star in the sky.<ref name=Hamaguchi>{{ cite journal |author=Hamaguchi K |author2=Yamauchi S |author3=Koyama K |title=X-ray Study of the Intermediate-Mass Young Stars Herbig Ae/Be Stars |journal=The Astrophysical Journal |year=2005 | arxiv=astro-ph/0406489v1 |bibcode = 2005ApJ...618..360H |doi=10.1086/423192 | volume=618 | page=260 }}</ref>"<ref name=AstrophysicalXraysource/> ==Galactic coronal clouds== {{main|Plasmas/Plasma objects/Coronal clouds/Galaxies|Galactic coronal clouds}} "Discussion of the alternative hypothesis of cloud ejection from the equatorial layer of the Galaxy leads to the conclusion that the gaseous halo must be highly turbulent and that the coronal clouds are probably [[w:H I region|H I region]]s".<ref name=Grzedzielski>{{ cite journal |author=Grzędzielski, S. |author2=Stępień, K. |title=On the Cloudy Structure of the Galactic Gaseous Corona |journal=Acta Astronomica |year=1963 |volume=13 |issue= |pages=143-56 |url= |bibcode=1963AcA....13..143G |doi= |pmid= |accessdate=2011-08-01 }}</ref> "One question posed by these previous observations is where the absorption originates. If a coronal cloud, the cloud is more than 15 kpc from the plane of NGC 3067. This distance is greater than the optical radius of the galaxy, 9.6 kpc (''H'' = 50 km s^-1 Mpc^-1. Furthermore, the narrow line requires that the cloud be cool, in contrast to the wide range of ionization stages detected for the corona of our Galaxy (Savage and deBoer 1981)."<ref name=Rubin>{{ cite journal |author=Rubin V. C. |author2=Thonnard N. T. |author3=Ford W. K. Jr. |title=NGC 3067 - Additional evidence for nonluminous matter |journal=Astronomical Journal |month=March |year=1982 |volume=87 |issue=3 |pages=477-85 |url= |bibcode=1982AJ.....87..477R |doi=10.1086/113120 |pmid= |accessdate=2011-08-01 }}</ref> "But if the cloud originates instead in the disk, and is moving in a circular orbit viewed at an inclination of 68 deg (the inclination of the optical galaxy), then some gas extends at least to 40 kpc, which is over four times the optical radius."<ref name=Rubin/> ==Quasars== {{main|Stars/Quasars|Quasars}} '''Def.''' "[a]n [[wikt:extragalactic|extragalactic]] object, [[wikt:star|starlike]] in appearance, that is among the most [[wikt:luminous|luminous]] ... objects in the [[wikt:universe|universe]]"<ref name=QuasarWikt>{{ cite web |title=quasar, In: ''Wiktionary'' |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=17 December 2014 |url=https://en.wiktionary.org/wiki/quasar |accessdate=2015-01-01 }}</ref> is called a '''quasar'''. [[w:3C 273|3C 273]] is a [[w:quasar|quasar]] located in the [[w:constellation|constellation]] [[w:Virgo (constellation)|Virgo]]. "In the 3C 273 case the emitting area would be about 3000 AU across if the emission were Planckian at 17,000 K, but this could be spread out over many smaller clouds, as suggested by Krolik and McKee."<ref name=Zirin78/> ==Interacting galaxies== {{main|Stars/Galaxies/Interacting|Interacting galaxies}} [[Image:Antennae before its deleted at commons.jpg|thumb|right|200px|This montage of Chandra images shows a pair of interacting galaxies known as The Antennae. The image at the lower right is processed and color-coded to show regions rich in iron (red), magnesium (green) and silicon (blue). Image is 4.8 arcmin across. Color code: Energy (Red: 0.3-0.65 keV, Green: 0.65-1.5 keV, Blue: 1.5-6.0 keV). Credit: .]] In the image at right of The Antennae, the top image, a wide field X-ray view, reveals spectacular loops of hot gas spreading out from the southern part of The Antenna into intergalactic space. In the closeup view on the lower left, the point sources have been taken out to emphasize the hot gas clouds in the central regions of The Antennae. The image at the lower right is processed and color-coded to show regions rich in iron (red), magnesium (green) and silicon (blue). "From the Chandra X-ray analysis of the [[w:Antennae Galaxies|Antennae Galaxies]] rich deposits of neon, magnesium, and silicon were discovered. These elements are among those that form the building blocks for habitable planets. The clouds imaged contain magnesium and silicon at 16 and 24 times respectively, the abundance in the [[w:Sun|Sun]]."<ref name=AstrophysicalXraysource/> {{clear}} ==Galaxy clusters== {{main|Stars/Galaxies/Clusters|Galaxy clusters}} [[Image:3C 295 Chandra.jpg|thumb|200px|right|This is a Chandra X-ray image of [[w:3C 295|3C 295]]. Image is 42 arcsec across. Credit: .]] [[Image:Central regions Perseus galaxy cluster.jpg|thumb|200px|left|Here the Chandra observations are of the central regions of the Perseus galaxy cluster. Image is 284 arcsec across. Color code: Energy (Red 0.3-1.2 keV, Green 1.2-2 keV, Blue 2-7 keV). Instrument: ACIS.]] [[w:3C 295|3C 295]] is a strongly X-ray emitting galaxy cluster in the constellation [[w:Boötes|Boötes]]. 3C 295 (Cl 1409+524) "is one of the most distant [[w:galaxy cluster|galaxy cluster]]s observed by [[w:X-ray telescope|X-ray telescope]]s. The cluster is filled with a vast cloud of 50 MK gas that radiates strongly in X rays. [The [[w:Chandra X-ray Observatory|Chandra X-ray Observatory]] detected] that the central galaxy is a strong, complex source of X rays."<ref name=AstrophysicalXraysource/> The cluster is located at J 2000.0 [[w:Right ascension|RA]] 14^h 11^m 20^s [[w:Declination|Dec]] −52° 12' 21". Observation date for the Chandra image is August 30, 1999. The Perseus galaxy cluster is located at J 2000.0 [[w:Right ascension|RA]] 03^h 19^m 47.60^s [[w:Declination|Dec]] +41° 30' 37.00". The observation dates for the image at right of 13 pointings are between August 8, 2002, and October 20, 2004. "The Perseus galaxy cluster is one of the most massive objects in the universe, containing thousands of galaxies immersed in a vast cloud of multimillion degree gas."<ref name=AstrophysicalXraysource/>{{clear}} ==Databases== {{main|Sciences/Databases|Databases}} From the [[w:SIMBAD|SIMBAD]] data base is a collection of objects which are both astronomical X-ray sources and coronal clouds. {| class="wikitable sortable" |+ Observed coronal clouds |- ! Source !! Abbreviation !! Number !! Known X-ray sources !! Known gamma-ray sources (gam) |- | [[w:Active galactic nucleus|Active galactic nucleus]] || AGN || 34,232 || 6265|| 386 |- | Astronomical gamma-ray source || gam + gB || 1872 + 7638 || 986 + 23 || 1872 |- | Astronomical infrared source || IR || 1,888,729 || 28,497 || 484 |- | Astronomical blue source || blu || 19,323 || 383 || 31 |- | Astronomical radio source || Rad || 487,066 || 5211 || 409 |- | Astronomical red source || red || 269 || 17 || 0 |- | Astronomical ultraviolet source || UV || 87,216 || 2767 || 119 |- | Astronomical X-ray source || X || 203,637 || 203,637 || 986 |- | Cloud || Cld || 8379 || 4 || 0 |- | [[w:Dark nebula|Dark nebula]] || DNe || 20,972 || 6 || 1 |- | Dwarf nova || DN* || 478 || 82 || 2 |- | Emission object || EmO || 11,837 || 181 || 9 |- | [[w:Galaxy|Galaxy]] || G || 1,287,663 || 5984 || 397 |- | [[w:HI region|HI region]] || HI || 5724 || 36 || 7 |- | [[w:HII region|HII region]] || HII || 25,654 || 198 || 6 |- | [[Interstellar medium]] || ISM || 4530 || 66 || 1 |- | [[w:Molecular cloud|Molecular cloud]] || MoC || 5679 || 7 || 3 |- | [[w:Nova|Nova]] || No* || 1360 || 74 || 13 |- | Nova-like star || NL* || 103 || 27 || 0 |- | [[w:Open cluster|Open galactic cluster]] || OpC || 2161 || 21 || 0 |- | [[w:Planetary nebula|Planetary nebula]] || PN || 10,737 || 48 || 2 |- | [[w:Quasar|Quasar]] || QSO || 148,801 || 5796 || 323 |- | [[w:Reflection nebula|Reflection nebula]] || RNe || 1799 || 7 || 0 |- | [[w:Star|Star]] || * || 1,792,160 || 18,291 || 227 |- | [[w:Supernova|Supernova]] || SN || 6391 || 21 || 7 |- | [[w:Supernova remnant|Supernova remnant]] || SNR || 1166 || 246 || 29 |- | [[w:Young stellar object|Young stellar object]] || Y*O || 8151 || 1694 || 0 |- |} ==Locations on Earth== {{main|Locations/Earth/Geography|Locations/Earth|Earth|Locations on Earth}} "Global maps illustrate the geographic region of visibility for each eclipse."<ref name=Espenak>{{ cite book |author=Fred Espenak |author2=Jay Anderson |title=Predictions for Total Solar Eclipses of 2008, 2009 and 2010, In: ''Solar Activity and its Magnetic Origin'' |publisher=Cambridge University Press |location= |year=2006 |editor=V. Bothmer & A. A. Hady |pages=495-502 |url=http://journals.cambridge.org/production/action/cjoGetFulltext?fulltextid=534480 |arxiv= |bibcode= |doi=10.1017/S1743921306002547 |pmid= |isbn= |accessdate=2013-07-10 }}</ref> ==Recent history== {{main|History/Recent|Recent history}} The '''recent history''' period dates from around 1,000 b2k to present. Initially the concept of a coronal cloud developed with observations of clouds or cloud-like structures forming above the photospheric surface of the Sun. "Coronal clouds, type IIIg, form in space above a spot area and rain streamers upon it."<ref name=Pettit43>{{ cite journal |author=Edison Pettit |title=The Properties of Solar Prominences as Related to Type |journal=Astrophysical Journal |month=July |year=1943 |volume=98 |issue=7 |pages=6-19 |url= |bibcode=1943ApJ....98....6P |doi=10.1086/144539 |pmid= |accessdate=2011-08-01 }}</ref> Type IIIg is a subdivision of sunspot prominences (class ''III'').<ref name=Pettit43/> "Occasionally dots form in space above a sunspot group. Other dots then appear, and all coalesce into a suspended cloud from which streamers pour into the spot area."<ref name=Pettit43/> "Occasionally one member of an interactive group has been a tornado prominence, but, for the first time, on January 4, 1945, a coronal cloud [[w:prominence|prominence]] of the [[w:sunspot|sunspot]] class was observed to participate in such an interaction."<ref name=Pettit>{{ cite journal |author=Edison Pettit |title=An Interactive Prominence |journal=Publications of the Astronomical Society of the Pacific |month=April |year=1945 |volume=57 |issue=335 |pages=97-9 |url= |bibcode=1945PASP...57...97P |doi=10.1086/125695 |pmid= |accessdate=2011-08-01 }}</ref> "The coronal cloud prominence ... formed in space, and from it streamers flowed into a neighboring prominence instead of into a spot area on the sun as is usual with coronal prominences."<ref name=Pettit/> "On January 5, a surge was photographed over the spot area, the coronal cloud being still visible. On January 6, a trace of the cloud was visible, but solar rotation soon carried the whole interactive group from the limb. The coronal cloud probably endured at least 2 days."<ref name=Pettit/> "On December 18, 1956, a large and active sunspot region was at the west limb of the sun."<ref name=Zirin59/> "Continuous emission from a dense coronal cloud was observed just before the flare. This cloud condenses sharply during the flare and dissipates afterward."<ref name=Zirin59>{{ cite journal |author=Harold Zirin |title=Physical Conditions in Limb Flares and Active Prominences. II. a Remarkable Limb Flare, December 18, 1956 |journal=Astrophysical Journal |month=March |year=1959 |volume=129 |issue=3 |pages=414-23 |url= |bibcode=1959ApJ...129..414Z |doi= 10.1086/146633 |pmid= |accessdate=2011-08-01 }}</ref> After a second class 2 flare occurred at 2131 U.T., "[a]t about 2200 U.T. a bright cloud appeared above the limb at the active region, reaching maximum surface brightness at 2208 and maximum total brightness at around 2220."<ref name=Zirin59/> "The flare at 2200 (the bright cloud) appears larger and brighter on the coronagraph photographs, but we are definitely looking at the same object."<ref name=Zirin59/> The initial "flare appears to have been a violent condensation of material from a dense coronal cloud above an active region."<ref name=Zirin59/> "The coronal temperature was 4000000°."<ref name=Zirin59/> ==Energies== {{main|Physics/Energies|Energies}} "[I]t appears that the energy requirements of coronal hole regions of the solar surface are substantially greater than those of other regions. The main factor determining this conclusion is an estimate of the energy required to accelerate the solar wind in regions above coronal holes. ... Alfven waves [are] more easily accommodated [by the energy budget than thermal plasma pressure]."<ref name=McWhirter1980>{{ cite journal |author=R. W. P. McWhirter |author2=D. B. Beard |title=The Energy Budget in and out of Coronal Holes [and Discussion] |journal=Philosophical Transactions of the Royal Society of London A Mathematical, Physical and & Engineering Sciences |month=July 29, |year=1980 |volume=297 |issue=1433 |pages=531-40 |url=http://rsta.royalsocietypublishing.org/content/297/1433/531.abstract |arxiv= |bibcode= |doi=10.1098/rsta.1980.0229 |pmid= |accessdate=2013-07-10 }}</ref> ==Magnetohydrodynamics== {{main|Plasmas/Magnetohydrodynamics|Magnetohydrodynamics}} '''Def.''' "the study of the interaction of electrically conducting fluids with magnetic fields"<ref name=Magnetohydrodynamics>{{ cite web |title=magnetohydrodynamics, In: ''Wiktionary'' |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=October 21, 2010 |url=http://en.wiktionary.org/wiki/magnetohydrodynamics |accessdate=2012-06-29 }}</ref> is called '''[[magnetohydrodynamics]]''' (MHD). In a coronal cloud are [[Magnetohydrodynamics|magnetohydrodynamic]] plasma flux tubes along magnetic field lines.<ref name=Aschwanden/> "[M]otions resulting from [a ''linear'' magnetohydrodynamic] instability act as a dynamo to sustain the magnetic field."<ref name=Brandenburg>{{ cite journal |author=Axel Brandenburg |author2=Åke Nordlund |author3=Robert F. Stein |author4=Ulf Torkelsson |title=Dynamo-generated Turbulence and Large-Scale Magnetic Fields in a Keplerian Shear Flow |journal=The Astrophysical Journal |month=June |year=1995 |volume=446 |issue=6 |pages=741-54 |url= |arxiv= |bibcode=1995ApJ...446..741B |doi=10.1086/175831 |pmid= |accessdate=2012-01-18 }}</ref> "Supersonic flows are initially generated by the Balbus-Hawley magnetic shear instability."<ref name=Brandenburg/> "A plasma with local magnetohydrodynamic instabilities creates mechanical turbulence, motion, or shear (a dynamo) which in turn generates or sustains the local magnetic field."<ref name=Radiativedynamo>{{ cite web |title=Radiative dynamo, In: ''Wikiversity'' |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=June 30, 2012 |url=http://en.wikiversity.org/wiki/Radiative_dynamo |accessdate=2012-06-29 }}</ref> ==Catalogs== {{main|Sciences/Catalogs|Catalogs}} "This catalog contains all the CMEs [about 7000] detected by the LASCO coronagraphs C2 and C3, which cover a combined field of view of 2.1 to 32 Rs."<ref name=Yashiro>{{ cite journal |author=S. Yashiro |author2=N. Gopalswamy |author3=G. Michalek |author4=O. C. St. Cyr |author5=S. P. Plunkett |author6=N. B. Rich |author7=R. A. Howard |title=A catalog of white light coronal mass ejections observed by the SOHO spacecraft |journal=Journal of Geophysical Research: Space Physics (1978-2012) |month=July |year=2004 |volume=109 |issue=A7 |pages= |url=http://onlinelibrary.wiley.com/doi/10.1029/2003JA010282/full |arxiv= |bibcode= |doi=10.1029/2003JA010282 |pmid= |accessdate=2013-07-10 }}</ref> ==Technology== [[Image:Stardust20110323-full.jpg|thumb|right|200px|This is an artist depiction of Stardust during the 'burn-to-depletion' phase which ended the mission and decomissioned to spacecraft on March 24, 2011. Credit: NASA/JPL.]] [[Image:Suisei.gif|thumb|left|200px|Suisei (the Japanese name meaning 'Comet') was launched on August 18, 1985 into heliocentric orbit to fly by Comet P/Halley. Credit: NASA.]] One of the objectives of the [[w:Stardust (spacecraft)|Stardust]] mission, specifically the Dynamic Science Experiment (DSE), is to "[s]ound the solar corona at X band [ [[radio astronomy]] ], including electron content of the inner corona, solar wind acceleration, turbulence, and a search for coronal mass ejections."<ref name=StardustSpacecraft>{{ cite web |title=Stardust (spacecraft) |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=June 27, 2013 |url=http://en.wikipedia.org/wiki/Stardust_(spacecraft) |accessdate=2013-07-09 }}</ref> "Suisei [at left] began UV observations in Nov. 1985, generating up to 6 images/day. The spacecraft encountered Comet P/Halley at 151,000 km on sunward side during March 8, 1986, suffering only 2 dust impacts."<ref name=Williams>{{ cite web |author=David R. Williams |title=NSSDC/COSPAR ID: 1985-073A |publisher=NASA |location=Washington, DC USA |date=July 1, 2013 |url=http://nssdc.gsfc.nasa.gov/nmc/masterCatalog.do?sc=1985-073A |accessdate=2013-07-10 }}</ref> "Suisei took a lot of UV pictures of the neutral hydrogen corona around the comet [Comet P/Halley]".<ref name=Hirao>{{ cite journal |author=K. Hirao |author2=T. Itoh |title=The Sakigake/Suisei Encounter with Comet P/ Halley |journal=Astronomy and Astrophysics |month=November 1, |year=1987 |volume=187 |issue=1&2 |pages=39-46 |url=http://adsabs.harvard.edu/full/1987A%26A...187...39H |arxiv= |bibcode=1987A&A...187...39H |doi= |pmid= |accessdate=2013-07-10 }}</ref> {{clear}} ==Hypotheses== {{main|Hypotheses}} # The volume of [[Plasmas/Plasma objects|plasma objects]] is greater than the volume of cold regions. ==See also== {{div col|colwidth=20em}} * [[Microquasar]] * [[Radiative dynamo]] * [[Sun as an X-ray source]] * [[Theoretical astronomy]] * [[Theoretical radiation astronomy]] * [[X-ray astronomy]] * [[X-ray classification of stars]] {{Div col end}} ==References== {{reflist|2}} ==Further reading== * {{ cite journal |author=McWhirter R. W. P. |author2=Kopp R. A. |title=The energy balance in the solar atmosphere above coronal holes |journal=Royal Astronomical Society, Monthly Notices |month=September |year=1979 |volume=188 |issue=9 |pages=871-81 |url= |bibcode=1979MNRAS.188..871M |doi= |pmid= |accessdate=2011-08-01 }} ==External links== * [http://www.ajol.info/ African Journals Online] * [http://www.bing.com/search?q=&go=&qs=n&sk=&sc=8-15&qb=1&FORM=AXRE Bing Advanced search] * [http://books.google.com/ Google Books] * [http://scholar.google.com/advanced_scholar_search?hl=en&lr= Google scholar Advanced Scholar Search] * [http://www.iau.org/ International Astronomical Union] * [http://www.jstor.org/ JSTOR] * [http://www.lycos.com/ Lycos search] * [http://nedwww.ipac.caltech.edu/ NASA/IPAC Extragalactic Database - NED] * [http://nssdc.gsfc.nasa.gov/ NASA's National Space Science Data Center] * [http://www.osti.gov/ Office of Scientific & Technical Information] * [http://www.questia.com/ Questia - The Online Library of Books and Journals] * [http://online.sagepub.com/ SAGE journals online] * [http://www.adsabs.harvard.edu/ The SAO/NASA Astrophysics Data System] * [http://www.scirus.com/srsapp/advanced/index.jsp?q1= Scirus for scientific information only advanced search] * [http://cas.sdss.org/astrodr6/en/tools/quicklook/quickobj.asp SDSS Quick Look tool: SkyServer] * [http://simbad.u-strasbg.fr/simbad/ SIMBAD Astronomical Database] * [http://nssdc.gsfc.nasa.gov/nmc/SpacecraftQuery.jsp Spacecraft Query at NASA] * [http://www.springerlink.com/ SpringerLink] * [http://www.tandfonline.com/ Taylor & Francis Online] * [http://heasarc.gsfc.nasa.gov/cgi-bin/Tools/convcoord/convcoord.pl Universal coordinate converter] * [http://onlinelibrary.wiley.com/advanced/search Wiley Online Library Advanced Search] * [http://search.yahoo.com/web/advanced Yahoo Advanced Web Search] <!-- footer templates --> {{Charge ontology}}{{tlx|Radiation astronomy resources}}{{Sisterlinks|Corona}}{{Sisterlinks|Coronal clouds}} <!-- categories --> [[Category:Astrophysics/Lectures]] [[Category:Plasmas/Lectures]] [[Category:Radiation astronomy/Lectures]] [[Category:Resources last modified in February 2020]] gskaolr9hq9xi579cvmqclhd4xf3hvh 0 139384 2413960 2413336 2022-08-12T14:05:48Z Young1lim 21186 /* Adder */ wikitext text/x-wiki {{nocat}} == Adder == * Binary Adder Architecture Exploration ( [[Media:adder.20131113.pdf |pdf]] ) {| class="wikitable" |- ! Adder type !! Overview !! Analysis !! VHDL Level Design !! CMOS Level Design |- | '''1. Ripple Carry Adder''' || [[Media:VLSI.Arith.1A.RCA.20211108.pdf |pdf]] || || [[Media:adder.rca.20140313.pdf |pdf]] || [[Media:VLSI.Arith.1D.RCA.CMOS.20211108.pdf |pdf]] |- | '''2. Carry Lookahead Adder''' || [[Media:VLSI.Arith.1.A.CLA.20211106.pdf |pdf]] || || [[Media:adder.cla.20140313.pdf |pdf]] || |- | '''3. Carry Save Adder''' || [[Media:VLSI.Arith.1.A.CSave.20151209.pdf |pdf]] || || || |- || '''4. Carry Select Adder''' || [[Media:VLSI.Arith.1.A.CSelA.20191002.pdf |pdf]] || || || |- || '''5. Carry Skip Adder''' || [[Media:VLSI.Arith.5A.CSkip.20211111.pdf |pdf]] || || || [[Media:VLSI.Arith.5D.CSkip.CMOS.20211108.pdf |pdf]] |- || '''6. Carry Chain Adder''' || [[Media:VLSI.Arith.6A.CCA.20211109.pdf |pdf]] || || [[Media:VLSI.Arith.6C.CCA.VHDL.20211109.pdf |pdf]], [[Media:adder.cca.20140313.pdf |pdf]] || [[Media:VLSI.Arith.6D.CCA.CMOS.20211109.pdf |pdf]] |- || '''7. Kogge-Stone Adder''' || [[Media:VLSI.Arith.1.A.KSA.20140315.pdf |pdf]] || || [[Media:adder.ksa.20140409.pdf |pdf]] || |- || '''8. Prefix Adder''' || [[Media:VLSI.Arith.1.A.PFA.20140314.pdf |pdf]] || || || |- || '''9. Variable Block Adder''' || [[Media:VLSI.Arith.1.A.VBA.20220811.pdf |pdf]] || || || |} </br> === Adder Architectures Suitable for FPGA === * FPGA Carry-Chain Adder ([[Media:VLSI.Arith.1.A.FPGA-CCA.20210421.pdf |pdf]]) * FPGA Carry Select Adder ([[Media:VLSI.Arith.1.B.FPGA-CarrySelect.20210522.pdf |pdf]]) * FPGA Variable Block Adder ([[Media:VLSI.Arith.1.C.FPGA-VariableBlock.20220125.pdf |pdf]]) * FPGA Carry Lookahead Adder ([[Media:VLSI.Arith.1.D.FPGA-CLookahead.20210304.pdf |pdf]]) * Carry-Skip Adder </br> == Barrel Shifter == * Barrel Shifter Architecture Exploration ([[Media:bshift.20131105.pdf |bshfit.vhdl]], [[Media:bshift.makefile.20131109.pdf |bshfit.makefile]]) </br> '''Mux Based Barrel Shifter''' * Analysis ([[Media:Arith.BShfiter.20151207.pdf |pdf]]) * Implementation </br> == Multiplier == === Array Multipliers === * Analysis ([[Media:VLSI.Arith.1.A.Mult.20151209.pdf |pdf]]) </br> === Tree Mulltipliers === * Lattice Multiplication ([[Media:VLSI.Arith.LatticeMult.20170204.pdf |pdf]]) * Wallace Tree ([[Media:VLSI.Arith.WallaceTree.20170204.pdf |pdf]]) * Dadda Tree ([[Media:VLSI.Arith.DaddaTree.20170701.pdf |pdf]]) </br> === Booth Multipliers === * [[Media:RNS4.BoothEncode.20161005.pdf |Booth Encoding Note]] * Booth Multiplier Note ([[Media:BoothMult.20160929.pdf |H1.pdf]]) </br> == Divider == * Binary Divider ([[Media:VLSI.Arith.1.A.Divider.20131217.pdf |pdf]])</br> </br> </br> go to [ [[Electrical_%26_Computer_Engineering_Studies]] ] [[Category:Computer architecture]] 9pzds4f7chb3ck4ytzoank3cm4hbol1 0 142235 2414038 2399279 2022-08-13T06:31:02Z 41.116.254.192 null wikitext text/x-wiki [[File:Ripple effect on water.jpg|thumb|right|300px|Notice how the [[Natural Inclusion/space|space]] of the water receives the energy of the waves. ]] {{TOC right | limit|limit=2}} <ref />connectivity, cohesiveness, and the intrinsically dynamic nature Fortunately we can learn to see through the illusion of dichotomies and definitions that has occluded our view of connectivity, [[Natural Inclusion/space|s]]<nowiki/>of the world.[[Natural Inclusion/space|pace]], energy, dispersions, and flow. Gaining this new perspective, we can then apply it to meeting the [[Grand challenges]]. The objectives of this course are to: *Meet the student where they now are in understanding that nature is intrinsically dynamic. *Examine the [[Natural Inclusion/space|space]], energy, [[Natural Inclusion/Boundaries|boundaries]], definitions, and flows of various natural systems.Perhaps the way we have been taught to look at the world makes it difficult to see its true nature. By focusing on objects, definitions, and static representations of the world we have overlooked flows, **Examine these elements from a variety of traditional perspectives. *Identify and explore the core concepts of Natural Inclusion. *See through the illusion of dichotomies and definitions that has occluded our view of connectivity, [[Natural Inclusion/space|space]], energy, and flow. *Understand that “All form is flow-form, an energetic configuration of [[Natural Inclusion/space|space]]”. *Relook at natural systems through the perspective of Natural Inclusion.~jy moet leer van natuur *Apply the perspective of Natural Inclusionality to meet the [[Grand challenges]]. There are no specific prerequisites to this course, however, some students may find it helpful to complete the [[Global Perspective]] course before beginning this one. The website [http://www.spanglefish.com/exploringnaturalinclusion/ Exploring Natural Inclusion] provides an extensive collection of references on the topic. A [[Natural_Inclusion/glossary_of_terms|glossary of terms]] used in this course that are new, unusual, or that are being used in unusual ways is provided to help the student grasp the course content more easily. Direct links to key concepts in the course are gathered in the [[Natural_Inclusion#Quick_Links|quick links]] section. This course is part of the [[Wisdom/Curriculum|Applied Wisdom curriculum]]. == Becoming Receptive == Each of us arrives here with our own unique background, experience, beliefs, and expectations. Some of this background will make us receptive to the new concepts of Natural Inclusion; other background will make it difficult to grasp these ideas. Please complete the following exercises to help identify and overcome various illusions that may be occluding your view of the world, and to begin your introduction to Natural Inclusion. === Dismissing False Dichotomies === Often we describe our world in terms of this or that, black or white, right or wrong, true or false, good or bad, heaven or hell, liberal or conservative, prosecution or defense, guilty or innocent, and other stark scenes of opposition. These distinctions often create false dichotomies that exclude fertile middle ground or other alternatives where creative solutions often reside. ==== Assignment ==== #Read this short [http://www.emotionalcompetency.com/distortions.htm#Pole essay on polarized thinking]. #Identify examples of polarized thinking, false dichotomies, false choices, or excluding middles that you perpetuate with your own language. #Recast your thinking and language to become more inclusive and more accurately characterize the full scope of what is. === Transcending Conflict === We regularly face conflict as we encounter contradictory goals. Too often we focus on differences as we try to avoid the conflict, deny it, insist on getting our way, resign ourselves to abandon our own goals, or become consumed as we fight to the bitter end. These ineffective strategies are often the result of seeing only false dichotomies, and focusing on opposing alternatives rather than creating new solutions. Becoming more inclusive often allows us to see a better way. ==== Assignment ==== [[File:Conflict5.gif|thumb|Five Possible Resolutions.]] #Complete the course on [[Transcending Conflict]]. #Identify some conflict you are facing, avoiding, or resenting. #Identify the five distinct resolutions that are possible, as illustrated in the diagram shown on the right. #Which of these five outcomes is most desirable for all involved parties? What outcome can be reasonably achieved? What new idea or resource had to be included to allow this solution? === Seeing Through Illusion === {{100%done}}{{By|lbeaumont}} Each of us faces convincing illusions every day that distract us from seeing the full extent of what is. Perhaps the most pervasive and persuasive illusion is that what I see is all there is. To attain a perspective receptive to Natural Inclusion it is important to recognize these illusions and strive to see through them. ====Assignment==== #Read the essay [[Global Perspective/Toward a Global Perspective—seeing through illusion|Toward a Global Perspective—seeing through illusion]]. #Identify the illusions that you have recognized and overcome as you have learned more about the world. These may include childhood beliefs as simple as the Santa Claus and Tooth Fairy stories, or more significant misunderstandings about the diversity and scope of the world, its people, and the universe. What caused you to see through these illusions? How did your worldview change as a result? #What illusions do you not yet see through? What can you do to see beyond these and expand your perspective? ===Follow the Light Beam=== Choose a beautiful evening when you can enjoy this next assignment. ====Assignment==== #Carry a flashlight outdoors on a clear night. Turn it on, point the beam skyward, count to three, and turn the beam off. #Contemplate the journey of the light waves as they travel through space at nearly 300 million meters per second. #What is always ahead of the light beam (i.e. out in front of the leading surface of the light) as it speeds into space? #Repeat the experiment, and move the beam rapidly in a zigzag or figure eight pattern. Contemplate the movement of the beam as it travels through space. Where is it now? How far will it travel? How long is it? #Describe the boundaries of the light beam, where it is in space, and where the energy flows. ===Enjoying Nature’s Beauty=== The more closely we examine nature, the more fascinating its intricate beauty becomes. Also, the more aware we are of the beauty of nature, the more we are able to see. ==== Assignment: ==== '''Part 1:''' Notice everyday beauty as follows: # Watch the sunrise # Take a walk somewhere nearby. Notice each beautiful thing you see or hear. Make a list of this everyday beauty. Look closely. Look closer. # Savor the beauty in your life. '''Part 2:''' Practice [[w:Miksang|''miksang'']]—good eye—as follows: # Read the article “[http://www.miksang.com/miksang.html What is Miksang]?” # Read the article “[http://www.alternativemedicine.com/beginners-mind/turn-lens-toward-your-life Turn a Lens Toward Your Life]”. # Follow the guidance given in the section “Capture the Moment” Note, no camera is necessary. The essence of the technique is in noticing the beauty. # Practice miksang aurally. Notice pleasant sounds such as song birds, running water, or children playing. (Evaluate the book ''The Old Ways: A Journey on Foot'', by Robert Macfarlane to include here as recommended reading.) ===Bubbles as Flow-Forms=== Enjoy watching this video of [http://www.youtube.com/watch?v=SpnuaQqzlQc Soap Bubbles Shrinking in Slow Motion], a demonstration of Partial Coalescence. [[File:Girl blowing bubbles.jpg|240px|thumb|Bubbles, space, flow, neighborhood, and community.]] ====Assignment:==== After watching the video, please answer these questions. #Can you describe a [[w:Soap_bubble|bubble]] without mention of the space within its volume? What does a bubble include? #Beginning 15 seconds into the video, how are the new bubbles created inside of the large bubble? Where do baby bubbles come from? #Consider the boundary of a particular bubble. Does that boundary separate the bubble interior from space, or does it separate space from the bubble interior? #When two bubbles merge (coalesce) describe what happens to the boundaries of each, and to the space encapsulated by each. Which of the two bubbles lives, and which one dies? #Bubbles change shape to minimize energy expenditure. For a bubble to persist, its primary need is to attune its activities and development to correspond with energy availability and hence with the local conditions of its environment. It is therefore clear that the availability of sources of energy is the principal influence that governs the growth, organization and function of these bubbles.<ref name="spacecut"> ''[http://link.springer.com/article/10.1007%2Fs12124-011-9154-y#page-2 Space Cannot Be Cut—Why Self-Identity Naturally Includes Neighbourhood]'', Alan David Rayner, Integr Psych Behav (2011) 45:161–184. </ref> #Can a bubble form independent of space? #Can a bubble form independent of energy? #Can a bubble exist independent of its neighborhood? A type of green algae, called ''[[w:volvox|volvox]]'', forms large spherical colonies. These form much like the bubbles in the above video, as can be seen in this video showing the [https://www.youtube.com/watch?v=nipgwvkx5-s middle and late reproductive stages of the volvox life cycle] and this video on [https://www.youtube.com/watch?v=cmSs157KvTg Sexual Reproduction in Volvox]. After watching these videos, answer the questions posed above substituting volvox for bubbles. Now, sit back, relax, and enjoy watching this [https://www.youtube.com/watch?v=27XvZReW_cs&NR=1&feature=endscreen lava lamp video]. Where is the space, where is the energy, where are the boundaries? ===Examining Plant Life=== Dr. [[w:Alan_Rayner|Alan Rayner]], an originator and primary authority on Natural Inclusion, was originally trained as a botanist. He developed key concepts from his observations of germination, growth, propagation, metabolism, and death of various plant forms. On February 13, 2013, he gave a lecture on The Art and Science of Understanding Plant Life at the [[w:Bath_Royal_Literary_and_Scientific_Institution|Bath Royal Literary and Scientific Institution]]. ====Assignment==== #Watch the video of his talk “[http://www.youtube.com/watch?v=fY04y8P0zwE The Art and Science of Understanding Plant Life]” #Describe the flows that sustain a tree #Describe a tree as a dynamic system. Be sure to describe various flows occurring on time scales of minutes, months, and years. ==Choosing Your Path== In his book ''[http://www.inclusional-research.org/inclusionalnature.php Inclusional Nature, Bringing Life and Love to Science]'' Dr. Alan Rayner describes the context, life circumstances, and evolving thought that led him to imagine, refine, describe, and pioneer the concepts of Natural Inclusion. He describes the path his journey is taking from the traditional thinking of ''abstract rationality'' to Natural Inclusion. With his insights now accessible through his writing, painting, and lecturing, we can each follow our own various paths to understanding Natural Inclusion. Many students may already be proficient in some traditional discipline, or have extensive background in some area. In this section of the course we begin with that background, and provide a path from your existing specialized background toward the core concepts of Natural Inclusion. Please scan the list of paths provided below, and choose at least one to follow that best matches your background or interest. For other paths, browse the various [http://www.inclusional-research.org/streams.php Inclusional Research Streams]. ===A Youngster's Path=== Young hearts and minds may be particularity open to grasping the concepts of Natural Inclusion, as in this imaginary dialogue: [http://www.bestthinking.com/articles/lifestyle/natural-inclusion-for-the-young-of-heart-and-mind Natural Inclusion for the Young of Heart and Mind]. ===An Engineer’s Path=== The gateway concept for an engineer to grasp is considering the world as a collection of [[w:System_dynamics|dynamic systems]]. If you have an engineering background, please read this essay: An Engineer’s Journey (currently in preparation). ===A Business Person's Path=== In the article [http://thenatureofbusiness.org/2013/11/01/from-natural-exclusion-to-natural-inclusion/ ''From natural exclusion to natural inclusion''], Giles Hutchins encourages businesses to learn from nature, reconsider the true nature of relationships and trade boundaries, broaden the scope when considering costs and benefits, and include all ''that is''. ===An Ecologist’s Path=== See: http://www.inclusional-research.org/biology.php ===A Philosopher’s Path=== See: http://www.inclusional-research.org/philosophy.php ===A Natural Scientist’s Path=== See: http://www.inclusional-research.org/physics.php ===A Theologian’s Path=== See: http://www.inclusional-research.org/theology.php ===A Spiritual Path=== See: http://www.inclusional-research.org/theology.php ===A Psychologist’s Path=== See: http://www.inclusional-research.org/psychology.php ==Observing the Natural World== With a deeper understanding of concepts forming a foundation for Natural Inclusion, we are ready to examine the flows occurring in a variety of important natural systems. ===Flows in Natural Systems=== While [[w:Engineering_drawing|engineering drawings]], diagrams, photographs, and even short-duration direct observations represent the world as stationary, natural systems are intrinsically dynamic. Consider these examples: [[Image:Water cycle.png|thumb|320px|Earth's [[w:Water_cycle|water cycles]] in ceaseless flows.]] *[[w:Universe#History_of_the_Universe|Formation of the Universe]] in time and space. Stars form, grow, explode and die. Galaxies are formed. Each of the chemical elements is formed. *Hydrology, fluid mechanics, calculus, engines, mechanical devices, electromagnetic waves, and alternating current are inherently dynamic. *All forms of [[w:wave|waves]] including surf, sound, light, and earthquakes are inherently dynamic; an extensive form of energy distributed in space. *Plants grow, live, breath, die and decay. *The [[w:Citric acid cycle|citric acid cycle]], [[w:Calvin cycle|Calvin cycle]], [[w:nitrogen cycle|nitrogen cycle]], and [[w:Carbon cycle|carbon cycle]] are all essential flows sustaining life on earth *Animals are conceived, grow, eat, breath, live, die and decay. * [[w:Ecosystem|Ecosystems]] are characterized by complex and dynamic relationships involving primary production, energy flows, decomposition, nutrient cycling, a range of function and biodiversity, and many ecosystem goods and services. *[[w:Continental_drift|Continents drift]], mountains are formed, rocks flow, earthquakes shake, wind blows, rain falls, water erodes, silt and dust drift. *[[w:Ocean_current|Ocean currents]] flow, tides ebb and flow, waves propagate, undulate and crash, beaches erode, barrier islands form and reform. *Weather describes continuous changes in temperature, pressure, humidity, winds, clouds, rain, snow, sleet, and hail. Clouds form, rain falls, streams and rivers flow. *Climates describe long term variations in weather patterns in time and space. *[[w:Storm|Storms]] form, winds blow, rain falls, lightning strikes, oceans surge, water rises, trees fall. *We are each conceived, gestate, are born, breath, eat, sleep, defecate, grow, learn, work, play, mate, age, die, and decay. *Elements combine, dust clouds drift, gravity receives, solar systems emerge, [[w:Nebular_hypothesis|planets form]], revolve, and rotate; [[w:Abiogenesis|life emerges]]. “Essentially, all models are wrong,” [[w:George_E._P._Box|George Box]] noted, “but some are useful.” Since the systems of the natural world are intrinsically dynamic, rather than static, these systems are better described using dynamic rather than static models, using language that emphasizes movement and flow rather than artificially imposing some static snapshot of the system. Also, neither the [[w:Reductionism|reductionism]] approach nor the [[w:Holism|holism]] approach to modeling nature is entirely effective. Natural Inclusion reconciles these two dichotomies and provides [[Natural_Inclusion/modeling|an inclusive approach to modelling nature]]. ==The Core Concepts of Natural Inclusion== We are now ready to briefly describe the core concepts of Natural Inclusion. '''Natural Inclusion''' is a radically new way of understanding '''evolutionary becoming''' as a process of '''cumulative energetic transformation''' or '''natural energy flow'''. Originally introduced by [[w:Alan_Rayner|Alan Rayner]], it applies to all scales of natural organization, from sub-atomic to cosmic, including '''biological [[w:Evolution|evolution]]'''. It arises from a '''core philosophical awareness''' of 'Natural Inclusionality', which recognizes that ''all form is flow-form, an energetic configuration of space''. This departs from '''definitive rationality''' in two fundamental ways. Firstly, natural [[Natural_Inclusion/Boundaries|boundaries]] are acknowledged to be ''intrinsically energetic'' 'dynamic interfacings' between distinct localities, not the 'inert limits' of discrete objects.<ref>Rayner, A.D.M.(1997), ''Degrees of Freedom - Living in Dynamic Boundaries''. London: Imperial College Press.</ref><ref name="Inclusionality">Rayner, A.D.M.(2004), ''Inclusionality and the role of place, space and dynamic boundaries in evolutionary processes''. Philosophica, 73, pp.51-70.</ref> Secondly, it is recognized that these natural [[Natural_Inclusion/Boundaries|boundaries]] can only be dynamic through the ''inclusion of space as infinite, intangible, frictionless presence''.<ref name="Inclusionality"></ref><ref name="spacecut"/><ref name="NaturesScope">Rayner, A.D.M.(2011b), ''NaturesScope: unlocking our natural empathy and creativity C an inspiring new way of relating to our natural origins and one another through natural inclusion''. O Books.</ref> Correspondingly, natural inclusion may be described as the ''co-creative, fluid dynamic transformation [[Natural Inclusion/modeling|of all through all]] in receptive spatial context''. An understanding of '''Natural Inclusionality''' can be gained from a wide variety of different viewpoints: philosophical, scientific, technological, mathematical, ecological, theological, artistic, educational, sociological, political, psychological, linguistic. By the same token, natural inclusionality has profound '''implications''' for a very wide variety of human endeavors and offers '''hope''' for resolution of some of the most intractable human '''problems''' and '''[[Grand_challenges|challenges]]''', which arise directly or indirectly from '''definitive rationality''' and that for thousands of years have resulted in profound '''conflict''' and '''suffering'''. Alan Rayner describes and illustrates these concepts in [http://youtu.be/8CGvQX3eNjI this short video]. === Art and Creativity === Artistic approaches can both be inspired by and help to develop and communicate inclusional perceptions of receptive space and dynamic boundaries, which can transform our understanding of evolutionary processes in biological, ecological, geological, cosmic and social systems. Lyrical writing, visual and performance art are very effective means of exploring these perceptions in an invitational and immediate way that can, without imposition, engage peoples' imagination and go beyond the restrictions of definitive language. Inclusionally, all patterns and processes in nature arise from the variable stiffening and yielding of fluid dynamic, spatial-informational medium (flow-form). Excessive stiffening results in the rigidity of 'fixed' or 'frozen' form, corresponding with the static linearly boxed (3-dimensional) and excluded space of [[w:Euclidean_geometry|Euclidean geometry]]. Excessive yielding results in formlessness. Correspondingly, creativity dynamically mixes informational rigidity (discipline) with spatial relaxation (letting go) so as to generate and explore an infinite array of possible forms of expression ('formings'). Any meaningful work of [[w:Art|art]] hence depends upon being both relaxed enough and disciplined enough to allow expression to flow into forming. This is when the [[w:Muse|Muse]] works her magic in the [[w:Liminality|liminal zone]] between conscious and unconscious realms in a way that can seem little short of miraculous when we become ‘[[w:Writer's_block|stuck]]’ between periods of creativity. The inhibition felt when the 'blank canvas', 'blank page', ‘block of wood, stone, metal or clay, and 'pregnant silence' freezes us into non-expression is like what happens when trying to swallow at will. As soon as we concentrate on the action or intention itself, our throat locks up - analysis becomes paralysis. To proceed at all, it is necessary to have the courage to 'let go' in an act of faith that all will or at least can be well. But the letting go has to be constrained if it is not simply to splurge. Ultimately the combined sense of having the courage to relax and allow whatever comes to mind or hand to emerge and surprise, along with the determination to maintain influence over what issues forth can fill with deep excitement, pleasure and awe - just as Nature does - on a good day. On a day and in a place where those defensive 'blocks' that paralyze so much of modern culture don't get in the way of our joyful expression. When we have the sense of being lovingly receptive—responsive channels, not grudgingly possessive, active-reactive authors demanding royalties for what flows through us from beyond our local reach. === Language and Linguistics === Definitive language reinforces definitive theory and practice in ever more intractable cycles. Hence whenever language is regarded as more than an aid to communicating our meanings and experiences, and acquires some kind of life of its own as our sole means of expression, it is a trap. We become entangled in a web of misunderstandings and arguments over exact meanings, where we desperately seek uniformity of usage to avoid ambiguity. But such uniformity runs counter to the rich variety and evolutionary possibility of life. We can gain such uniformity only through not being able to express our appreciation of what living really means in all its dynamic depth and complexity. By restricting our communications to what can be articulated explicitly, we leave aside, out of sight and out of mind, the enormity of implicit experience. Through inclusional awareness it may not only be possible to recognize this language trap but also to find ways of avoiding it. Firstly, we can use language and metaphors that tend to sustain fluid possibility and don’t reinforce concepts of definitive closure. For example, we can use the language of water, not the language of concrete in our descriptions of life and evolution. Secondly, through appreciating how the meaning of words is influenced, sometimes radically, by the context in which they are being used, we can make clear that the context is inclusional. The meaning of ‘information’, for example, is definitive when used in a rationalistic context, but dynamic relational in an inclusional context. Use [http://www.emotionalcompetency.com/dialogue.htm dialogue], rather than a more [http://www.emotionalcompetency.com/tone.htm polarizing form of communication] whenever possible. More on inclusional language, including suggested alternative word choices, is provided in this [http://www.inclusionality.org/index.php?option=com_content&view=article&id=6&Itemid=15 article on inclusional language]. === Principles === The '''intention''' of this course is to explore the meaning and implications of natural inclusion from these diverse viewpoints. But before setting out on this exploration, it is worth pointing out that in order to understand the '''basic principles''' of natural inclusionality, it is ''not necessary'' to have extensive prior knowledge, and indeed this can be an obstacle because the way we have predominantly taught ourselves to think over the last few thousand years actually profoundly contradicts the way we naturally are in the world as it naturally is as flow-forms - energetic configurations of [[Natural Inclusion/space|space]]. All we '''actually''' have to do to understand these basic principles is to ask ‘what needs to be present for natural form to be distinguishable?’ Or, more concretely, ‘why is our direct experience of walking into a brick wall different from that of walking through an open doorway?’ Or, ‘what makes it possible to paint a picture?’ It then becomes apparent that the only way of answering these questions is to acknowledge the occurrence of ''at least'' two kinds of natural presence: a ''receptive context'' or medium which provides ''freedom for local movement and/or expression'', '''and''' ''local formative content'', which ''informs'' or ''configures'' that context. The former is necessarily ''spacious'', the latter necessarily ''cohesive''. Moreover, for form to be and become distinguishable, each of these presences must naturally include the other. Spacious presence alone would be formless void, and formative presence alone would have no shape or size. They are necessarily distinct, but mutually inclusive presences. They can neither be abstracted from one another as independent entities, nor be homogenized into ‘Oneness’. The only way in which this necessity can be fulfilled is for one of these presences, natural [[Natural Inclusion/space|space]], ultimately to be ''everywhere'', continuous, intangible (i.e. frictionless) and immobile, and for the other ultimately to be ''somewhere'', distinctive, tangible and ''continually'' in motion. Natural [[Natural Inclusion/space|space]] and figural [[Natural_Inclusion/Boundaries|boundaries]] are hence, respectively, ''continuous'' and ''dynamically distinct'' (i.e. dynamically continuous) ''energetic interfacings'' between the insides and outsides of all natural forms as ''flow-forms''.<ref name="Inclusionality"></ref><ref name="spacecut"/><ref name="NaturesScope"></ref> The natural world is better understood and described by focusing on: *'''Energy'''—the presence of mobility, *'''[[Natural Inclusion/space|Space]]'''—the continuous, immobile, intangible presence that becomes configured and reconfigured into distinctive localities by natural energy flow. Read this in-depth discussion of [[Natural Inclusion/space|space]] for a deeper understanding of this concept. *'''Flow'''—continuous change in locality, *[[Natural_Inclusion/Boundaries|'''Boundaries''']]—energetic interfacings. Read this in-depth discussion of [[Natural Inclusion/Boundaries|boundaries]] for a deeper understanding of this concept. * [[Natural_Inclusion/modeling|'''Each in the Other''']] — recognizing that [[Natural Inclusion/space|space]] permeates [[Natural Inclusion/Boundaries|boundaries]]. Rejection of [http://www.emotionalcompetency.com/distortions.htm#Pole false dichotomies]. *'''Dispersions'''—complex flows distributed in space and time, and *'''Flow-forms'''—localities of flow Explore! ====Assignment==== #Choose some natural system of flows. This might be chosen from the section “[[Natural_Inclusion#Flows_in_Natural_Systems|Flows in Natural Systems]]” above, or from some other source. #Describe the system in terms of the energy, [[Natural Inclusion/space|space]], flow, [[Natural Inclusion/Boundaries|boundaries]], flow-forms, and [[Natural_Inclusion/modeling|each in the other]]. ==All form is flow-form, an energetic configuration of space== In general terms, natural inclusionality is a kind of awareness that helps us to appreciate our selves and other tangible forms as dynamic inhabitants of Nature, not discrete subjects and objects rigidly set apart from one another.<ref>[http://www.bestthinking.com/articles/science/biology_and_nature/ecology/inclusional-sustainability Inclusional Sustainability: A Natural Way of Life], by Alan Rayner, BestThinking, </ref> At the heart of inclusionality is a simple but radical shift in the way we frame reality, from ''absolutely fixed'' to ''relationally dynamic''. This shift arises from perceiving [[Natural Inclusion/space|space]] and [[Natural_Inclusion/Boundaries|boundaries]] as connective, reflective and co-creative, rather than severing, in their vital role of producing heterogeneous form and local identity within a featured rather than featureless, dynamic rather than static, Universe.<ref>''[http://www.inclusional-research.org/inclusionalnature.php Inclusional Nature, Bringing Life and Love to Science]'', by Alan Rayner </ref> The ''simple move from regarding [[Natural Inclusion/space|space]] and [[Natural_Inclusion/Boundaries|boundaries]] as sources of discontinuity and discrete definition to sources of continuity and dynamic distinction'' is the ecological and evolutionary point of departure of ‘natural inclusionality’ from objective rationality.<ref name="spacecut"/> By acknowledging ourselves as distinct but not isolated local inclusions of natural energy flow, it is always possible gracefully to accept what we receive, to nurture and make the best of it, eventually to pass it on.<ref name="spacecut"/> Alan Rayner summarizes the idea succinctly: "Think of it this way - by imaginatively contemplating the question of what makes any natural form distinguishable from its surroundings? It becomes apparent that the only way of answering this question is to acknowledge the occurrence of ''at least'' two kinds of natural presence: ''a receptive context'' or non-resistive medium, which provides ''freedom for local movement and/or expression'', AND ''local formative content'', which ''informs'' or ''configures'' that context. The former is necessarily ''spacious'', the latter necessarily ''cohesive''. Moreover, for form to be and become distinguishable, ''each of these presences must naturally include the other''. Spacious presence alone would be formless void, and formative presence alone would have no shape or size. They are necessarily distinct, but mutually inclusive presences. They can neither be abstracted from one another as independent entities, nor be homogenized into ‘Oneness’. The only way in which this necessity can be fulfilled is for one of these presences, natural space, ultimately to be ''everywhere'', continuous, intangible (i.e. frictionless/non-resistive) and immobile, and for the other ultimately to be ''somewhere'', distinctive, tangible and ''continually'' in motion. Try whirring your hand around in front of your face until it appears as a blur, and you may get a feel for how all distinguishable form will ultimately appear this way when viewed sufficiently closely (i.e. at sufficient magnification) and for sufficient duration - if the whirring stops even for a moment, so too does 'time', and the mutual inclusiveness of each in the other breaks down irretrievably. Natural space and figural boundaries are hence, respectively, ''continuous'' and ''dynamically continuous energetic interfacings and distinctions between the insides and outsides of all natural forms as flow-forms.''" He goes on to say: "Whenever I see a contradiction between two supposed opposites, I feel there must be a deeper way to consider them that will reveal an underlying need of each for the other. Whenever I see a pattern in some phenomenon or concept (historic or contemporary), I automatically and intuitively notice resemblances to some other phenomenon or concept. I do this with wildlife, with science, with writing, with art, and seemingly every other area of interest that has fired my imagination over the decades. I simply cannot avoid doing that, and wouldn't want to. Once I called it 'looking for connections', until I realized that language didn't evoke the right image in my mind. Nowadays, I would call it 'looking for affinities'. This is why I have come to regard 'evolutionary ecology' - the study of pattern, process and relationship at any scale, the most basic of all forms of NATURAL scientific enquiry." ===A Fresh Look at Natural Systems=== ===Putting Natural Inclusionality into Practice=== "We must draw our standards from the natural world. We must honor with the humility of the wise the bounds of that natural world and the mystery which lies beyond them, admitting that there is something in the order of being which evidently exceeds all our competence." --[[w:Vaclav Havel|Vaclav Havel]], president of the Czech Republic Reconceiving many of our social and political institutions and basing them on the principles of Natural Inclusion provides new solutions. Here are some examples. ====In Design==== [[File:Leaf_1_web.jpg|thumb|right|300px|Flows create form in flow-form networks.<ref> [http://www.actionresearch.net/living/tesson.shtml ''Dynamic Networks, An interdisciplinary study of network organization in biological and human social systems'']., Karen June Tesson, Doctoral Dissertation, University of Bath, Department of Psychology, June 2006 </ref> ]] Nature itself is the greatest master of Natural Inclusion. [[w:Biomimicry|Biomimicry]] pioneer [[w:Janine_Benyus|Janine Benyus]] encourages designers to ask “How would nature solve this problem?” and then observes “Learning ''about'' the natural world is one thing, learning ''from'' the natural world—that’s the switch. That’s the profound switch.”<ref>[http://www.ted.com/talks/janine_benyus_shares_nature_s_designs.html Janine Benyus: The promise of biomimicry], TED Talk</ref> [[w:Biomimicry|Biomimicry]] is the examination of nature, its models, systems, processes, and elements to emulate or take inspiration from in order to solve human problems. In many natural systems local configurations based on energy balance lead to efficient, enduring designs where essential [[w:Emergence|properties emerge]]. Design paradigms based on [[w:Self-organization|self-organization]] and local context contrast with the typical top-down, central control-oriented design of so many human-designed systems. Examples include ant colonies, bee colonies, flocks of migrating birds, animal skins, leaves, insect anatomy, water flows, healing mechanisms, microscopic surface features, solar energy capture, wind energy capture, membranes, fibers, colors without pigments, parallel processing, lightweight structures, and strong materials. There are many [[w:Patterns_in_nature|patterns in nature]]. Natural systems are successful; they have proven their ability to survive—some species are billions of years old—through a range of environmental conditions. “We live in a competent universe.”<ref>Janine Benyus: [http://www.ted.com/talks/janine_benyus_biomimicry_in_action.html Biomimicry in action], TED Talk</ref> Often success is based on remarkably efficient approaches to capturing and using energy. These solutions evolved in context. “Life creates conditions conducive to life.” Designers who have looked to nature for inspiration have developed elegant solutions to difficult problems. Studying natural flows inspired these innovative products: The [http://www.aquaporin.dk/ AQUAporin] company is creating a new class of water filtration membranes based on [[w:Aquaporins|aquaporins]]—a naturally occurring protein central to the functioning of Human kidneys— as cornerstones in water filtering devices to be employed in industrial and household water filtration and purification. These filters, based on flows and [[Natural_Inclusion/Boundaries|boundaries]] in the human kidney, can play a role in making fresh water more widely available. [http://www.biopowersystems.com/ BioPower Systems] is developing bioWAVE^TM units to provide utility-scale electric power production from ocean waves. Its design, inspired by aquatic plants, combines high conversion efficiency with the ability to avoid excessive wave forces, enabling supply of grid-connected electricity at a competitive price per [[w:Kilowatt_hour|megawatt hour]]. The [http://www.paxscientific.com/ PAX Scientific] product design firm has designed a more efficient [[w:impeller|impeller]] and [[w:turbine|turbine]] based on recurring natural patterns of [[w:Vortex|vortical flow]]. Inspiration came in part from studying the spiral movement of kelp in response to water movement. Designing the front of a high-speed train based on the [[w:kingfisher|kingfisher’s]] beak allows more efficient transitions through the air pressure difference encountered when entering a tunnel at high speeds. This allows the [[w:Shinkansen|Shinkansen]] Bullet Train to run more quietly while requiring less energy.<ref> [http://www.biomimicryinstitute.org/case-studies/case-studies/transportation.html Learning Efficiency from Kingfishers]</ref> =====Assignment===== #Watch at least one of these videos on biomimicry: ##Janine Benyus: [http://www.ted.com/talks/janine_benyus_shares_nature_s_designs.html The promise of biomimicry] ##Janine Benyus: [http://www.ted.com/talks/janine_benyus_biomimicry_in_action.html Biomimicry in action] ##Michael Pawlyn: [http://www.ted.com/talks/michael_pawlyn_using_nature_s_genius_in_architecture.html Using nature's genius in architecture] #Browse the design solutions shown in this [http://www.asknature.org/product/highlight/NYSERDA+Energy gallery of products]. #Identify at least one specific [[w:Biomimicry|biomimicry]] approach and describe how it can address a particular [[Grand challenges|Grand Challenge]]. # You may also be interested in this related video on self-assembly technology. Skylar Tibbits: [http://www.ted.com/talks/skylar_tibbits_the_emergence_of_4d_printing.html The emergence of "4D printing"]. ====In Economics==== Traditional [[w:Economics|economics]] is based on several assumptions that exclude, rather than include nature. The value of [[w:Natural_capital|natural assets]], especially [[Limits_To_Growth#Ecosystem_Services|ecosystem services]], is typically ignored in financial calculations. Although these services are essential, we rarely account for their value in our economic models. For example, pollination of crops by bees is required for 15-30% of U.S. food production, yet the services of the bees themselves (as distinct from beekeeping activities) are regarded as free. One study estimates the value of ecosystem services world-wide at approximately $33 trillion per year. A similar example is the way in which extracted minerals, such as oil, is accounted for. Although the oil itself has value, even before it is discovered and extracted, financial systems attribute value primarily after it is extracted. An inclusive accounting system would treat petroleum sales as liquidation of a capital asset, rather than as income. It is important to distinguish between ''economies''—the exchange of goods and services—and ''economics''—a money-based model of an economy. “Essentially, all models are wrong,” [[w:George_E._P._Box|George Box]] noted, “but some are useful.” Unfortunately the models we use in our financial accounting systems diverge significantly from a value-based economy. Perhaps asking "what else is happening" can help draw your attention away from the narrow financial transaction to notice the full extent of the economic exchange, both positive and negative, that is taking place. Traditional economics relies on several premises which are clearly false: #Growth can continue indefinitely, #[[w:Externality|Externalities]] can be safely ignored, #Natural resources represent income that increases as they are extracted rather than capital which depreciates as it is depleted, and #Resources can be substituted for one another with infinite flexibility.<ref>{{cite book |title=The End of Growth: Adapting to Our New Economic Reality |last=Heinberg |first=Richard |year=2011 |publisher=New Society Publishers |isbn=978-0865716957 |pages=336}}</ref> In contrast, an inclusive economic model would: #Acknowledge [[Limits To Growth|limits to growth]], #Account fully for [[w:Externality|Externalities]], #Treat natural resource extraction and consumption as liquidation of a [[w:Capital_(economics)|capital resource]], #Recognize that many resources are unique. The emerging fields of [[w:Ecological_economics|ecological economics]] and [[w:Environmental_economics|environmental economics]] begin to address these issues. =====Assignment===== How do you prefer to spend a day? Perhaps you would enjoy hiking with someone through the local county park, seeing the natural beauty, listening to the sounds of nature, and noticing some wildlife while getting healthy exercise and strengthening a friendship. Alternatively you might enjoy a day at Disney World, mingling with the crowds, enjoying amusement rides, and meeting the Disney characters. While these two options may have similar value to you, the first costs little or nothing, and the second costs plenty.<ref>[http://blog.grdodge.org/2012/06/25/time-is-money-so-take-it-to-the-bank-and-other-community-building-ideas/ Time is Money, So Take It to the Bank (and Other Community Building Ideas)], Leland R. Beaumont, The Dodge Blog, June 25, 2012</ref> #If the county park and [[w:Walt_Disney_World|Disney World]] both charged admission, what relative charge do you think fairly represents the value of each experience? What do you think is a fair way to preserve the various [[w:Commons|commons]] we rely on? #Complete the assignment in the [[Limits_To_Growth#Ecosystem_Services|Ecosystem Services]] section of the Limits to Growth course. #Study the section on [[Global_Perspective#Externality|Externality]] (from the Global perspective course) and complete the assignment in that section. ====In Education==== With our understanding of Natural Inclusion the goal is for the student and teacher to enter a creative space where they can participate in co-creating a learning experience. [[w:Wikiversity|Wikiversity]] itself is an example of an inclusive learning environment. Because anyone can contribute to the creation, expansion, and improvement of course materials, energy of students and teachers is welcomed into the creative space of the courses. [[Help:Talk_page|Talk pages]] and other feedback channels help align students and teachers with the learning opportunities. There are many examples of [[w:Open education|open education]], each seeking to eliminate barriers to entry and increase student involvement. =====Assignment===== #Study this chart illustrating [http://www.thewisepath.org/papers/learning%20loop.pdf learning at the speed of thought]. #Identify a problem you would like to explore, pose a particular question you would like to answer, or identify some course of learning you would like to engage in. #Choose some [[w:Open_education|open education]] resource, perhaps within the [[w:MediaWiki|MediaWiki]] projects, or some other [[w:Open_education|open education]] resource. #Use the [[w:Open_education|open education]] resource to answer your question, move toward the solution of the selected problem, or pursue a course of learning. #Continue [http://www.thewisepath.org/papers/learning%20loop.pdf learning at the speed of thought] as you progress around the cycle. ====In Government==== Various forms of government, proposed and in practice, that seek to increase the involvement of more people in understanding issues, [http://www.emotionalcompetency.com/dialogue.htm dialoging] on concerns, proposing solutions, and making decisions are consistent with the general concepts of Natural Inclusion. Various forms of [[w:democracy|democracy]], especially including [[w:direct democracy|direct democracy]], and [[w:participatory democracy|participatory democracy]], are examples. A number of [[w:Transpartisan|transpartisan]] organizations strive to enter the space between polarized political positions, seek common ground, and offer new solutions. Transpartisanship acknowledges the validity of truths across a range of political perspectives and seeks to synthesize them into an inclusive, pragmatic container beyond typical political dualities. Such organizations include [[w:No_Labels|No Labels]], [[w:Coffee_Party|Coffee Party USA]], and [[w:FactCheck.org|FactCheck.org]] in the United States. The website [[w:openDemocracy.net|openDemocracy.net]] offers news and opinion articles covering current issues in world affairs. Using the slogan "Free thinking for the world", it seeks solutions that promote human rights and democracy, rather than advocating the traditional, polarizing ideologies. =====Assignment===== #Choose some issue to study that is deadlocked in debate between conservative and liberal politicians. If possible, choose one of the [[Grand challenges]] to focus on for this assignment. #Describe the conservative position on the issue. Describe the liberal position on the issue. #Adopt a point of view that transcends both the conservative and liberal positions to seek a solution that is best for the people being governed. Create alternatives for mutual gain. What creative, yet practical, solutions can you suggest? ====In Human Interplay==== No one can live while isolated from the environment. Physiologically we all need to breathe, drink, and eat, while we exhale, perspire, and excrete waste. We all consume energy to heat and cool homes, cook food, light spaces, and transport ourselves and our goods. Our [[w:Carbon_footprint|carbon footprint]] tries to take account of this need (and neediness). Socially, many of us crave human companionship, and feel bereft and powerless on our own. In short, we all benefit from ''participation''; engaging with others in our community to solve problems, manage our environment, and connect with each other to build, maintain and improve our [[What_Matters/Community|community]]. When we are able to [http://www.emotionalcompetency.com/self.htm#Detaching open up our egos], learn to co-create rather than compete, work together to protect the [[w:Commons|commons]], and appreciate both our similarities with our neighbors and our differences, this can certainly be [[What_Matters/Play|fun]] – and indeed profoundly inspiring. When we can attain and even transcend a [[Natural_Inclusion#Seeing_Through_Illusion|global perspective]], [[What_Matters/Compassion|feel compassion]], and become [[Virtues/Generosity|generous]], we all gain. =====Assignment:===== # Practice the skill of [http://emotionalcompetency.com/dialogue.htm dialogue], it is the art of ''participating'' in conversation. Use dialogue as a way to receive understanding from others, and allow them to receive understanding from you. #Read the module on [[What_Matters/Community|Community]] (from the What Matters course), and complete the assignments in that module. # Complete the course on [[Virtues|virtues]]. #Read the section on [[Limits_To_Growth#Ecological_footprint|Ecological Footprint]] (from the Limits to Growth course), and compete the assignment in that section. # Work to identify and include the various [[w:Externality|externalities]] you have been overlooking. Study the section on [[Global_Perspective#Externality|Externality]] (from the Global perspective course) and complete the assignment in that section. #What can you do to increase your participation and begin to address some of the [[Grand_challenges|Grand challenges]]? Do so. ====Land Use==== [[w:Wetland|Wetlands]], [[w:Coastal_geography|coastal regions]], [[w:Littoral_zone|littoral zones]], [[w:Barrier_island|barrier islands]], [[w:Waterway|waterways]], [[w:Fault_(geology)|earthquake zones]], [[w:Forest|forests]], and even [[w:desert|deserts]] are flow-forms; inherently dynamic land areas. Land [[w:deed|deeds]] use a static model to describe dynamic land forms, creating a fundamental mismatch. A new model of land ownership based on the dynamic nature of earth, water, climate, and weather is needed. (Are there any ideas here? Nomads lived dynamically, but the lifestyle seems difficult.) =====Assignment===== #Choose some [[w:Natural_disaster|natural disaster]] to study. This might be a flood, tsunami, blizzard, hurricane, typhoon, drought, heat wave, tornado, or wildfire. Major tragic events include: the [[w:Dust_Bowl|dust bowl]], the [[w:2004_Indian_Ocean_earthquake_and_tsunami|2004 Indian Ocean earthquake and tsunami]], [[w:Hurricane_Katrina|Hurricane Katrina]], the [[w:2011_Tohoku_earthquake_and_tsunami|2011 Tōhoku earthquake and tsunami]], climate change impacts on [[w:Climate_change_in_Tuvalu|Tuvalu]], and [[w:Hurricane_Sandy|Hurricane Sandy]]. #Describe how representing a flow-form with some static model contributed to the disaster. #To what extent are these tragedies the result of human error (an occluded view of the world) rather than truly natural? ====In Religion==== Imagine a religious belief system and forum that was centered on [[dignity]], universal [[w:Human_rights|human rights]], [[w:Fundamental_human_needs|human needs]], human [[w:Quality_of_life|well-being]], and [[w:Spirituality|spiritual]] longing, rather than on arbitrary religious [[w:Dogma|dogma]]. Imagine a religious organization that welcomed everyone because it honored the similarities of the needs and beliefs of the people, rather than excluding and opposing people who hold arbitrarily different beliefs. Imagine a safe space that welcomed inquiry, exploration, [[w:Skepticism|skepticism]], faith, and [http://emotionalcompetency.com/dialogue.htm dialogue] into the existential, spiritual, moral, and developmental questions we all have. Thoughtful and curious people open to experience and skeptical of the universal veracity of divine [[w:Revelation|revelations]] and sacred [[w:Scriptures|scriptures]] practice various forms of [[w:Nontheism|nontheism]] to meet their human and spiritual needs. =====Assignment===== #Read the [http://charterforcompassion.org/the-charter/ text] of the [[w:Charter_for_Compassion|charter for compassion]]. #Read the essay on [http://theycallmelee.blogspot.com/2010/11/from-destructive-dogma-to-constructive.html transcending dogma]. # Develop the [[Virtues/Tolerance|virtue of tolerance]]. Know its full extent and its limits. Practice tolerance. #Develop your own robust [http://emotionalcompetency.com/theoryofk.htm theory of knowledge] so you can be clear about why you believe what you believe. [[Knowing How You Know|Know how you know]]. # List existential, spiritual, or moral questions you seek guidance with. #Find an inclusive forum for exploring those questions and developing satisfactory answers. This might be discussions with a trusted friend or mentor, research into theories on the [[w:Cosmogony|origins of the universe]] and the [[w:Origins_of_life|origins of life]], study of [[w:Human_rights|human rights]] and [[virtues]], [[w:Contemplation|contemplation]], [[w:Introspection|introspection]], or [[w:Meditation|meditation]], some inclusive religious sect such as the [[w:Unitarian_Universalism|Unitarian Universalism]] church, [[w:Humanism|humanism]], or some other group more concerned with [[w:Spirituality|spirituality]] than [[w:Dogma|dogma]]. # Learn to [[Quiet Mind|quiet your mind]]. ==Meeting the Grand Challenges== The value of Natural Inclusion concepts can best be measured by their ability to improve overall well-being. How can an understanding of Natural Inclusion help us overcome the [[Grand challenges]]? The following table illustrates how Natural Inclusion concepts address the various Grand Challenges. The column headings are linked to the corresponding headings in this NI course, and the row labels are linked to the corresponding section in the [[Grand challenges]] course. Each cell entry describes how the Natural Inclusion approach addresses the corresponding Grand challenge. {| class="wikitable" |- ! NI Concept: !! [[Natural_Inclusion#In_Design|'''Design''']] !! [[Natural_Inclusion#In_Economics|'''Economics''']] !! [[Natural_Inclusion#In_Education|'''Education''']] !! [[Natural_Inclusion#In_Government|'''Government''']] !! [[Natural_Inclusion#In_Human_Interplay|'''Human Interplay''']] !! [[Natural_Inclusion#Land_Use|'''Land Use''']] !! [[Natural_Inclusion#In_Religion|'''Religion''']] |- |[[Grand_challenges#Physical_Health|'''Physical Health''']]|| Biomimicry Water Solutions|| Value Water Commons || || || || Preserve Ecosystems || |- |[[Grand_challenges#Mental_Health|'''Mental Health''']]|| || || || || Community participation improves mental health. || || Increased harmony reduces stress |- |[[Grand_challenges#Economic_and_Social_Opportunity|'''Opportunity''']]|| || More accurate accounting systems include more people. || Education increases opportunity || || || || Emphasis on human rights increases opportunity |- |[[Grand_challenges#Safety_and_Security|'''Safety''']]|| || || Education reduces crime and violence. || || Participation reduces violence and crime. || || Increased harmony reduces conflict. |- |[[Grand_challenges#Stability|'''Stability''']]|| || || || || Engage Across Classes and Hierarchies || || Increased harmony reduces conflict. |- |[[Grand_challenges#Environmental_Stewardship|'''Environmental Stewardship''']]|| Design efficiencies reduce resource consumption. || Value Environments, Value Eco Services, Value the Commons || Better understanding of environment’s value || || || Preserve Ecosystems || We are all stewards of the creation. |- |[[Grand_challenges#Government_Policy|'''Policy''']]|| || More accurate accounting reduces distortions. || Better informed policy makers. || Include more people in decision making. || Participation increases inclusion. || Improve land use utility. || Based on well-being rather than ideology. |- |[[Grand_challenges#The_Range_of_Opportunities:|'''Flourishing''']]|| Improved Aesthetics || Valuing the best things in life. || Education provides enrichment. || Government promotes well-being || Participation is enrichment. || Improved Aesthetics. || Continued spiritual growth. |} ====Assignment==== # Choose one cell in the above table to study in depth. # Describe in detail how the relevant NI approach addresses the corresponding grand challenge. # Create an action plan for using that approach to address the challenge. # Carry out that action plan. ==Quick Links== Direct links to key NI concepts are gathered here for easy access. * [[Natural_Inclusion/space|Space]]—the continuous, immobile, intangible presence that becomes configured and reconfigured into distinctive localities by natural energy flow. * [[Natural_Inclusion/Boundaries|Boundaries]]—energetic interfacings. Boundaries identify a shift between inner and outer contexts; boundaries face both ways. **[http://thewisepath.org/papers/Dynamic%20Interfacinged.pdf Dynamic Interfacing, the Vitality of Each in the Otherness], a slide presentation * Modeling Nature, [[Natural_Inclusion/modeling|Each in the Other]] — recognizing that space permeates boundaries ** Including [[Natural_Inclusion/modeling#Summaries|several summaries]] of this concept. * [[Natural_Inclusion/glossary_of_terms|Glossary of Terms]] ==Resources:== The resource materials listed here are useful for continued study of Natural Inclusionality. *[http://www.spanglefish.com/exploringnaturalinclusion/ Exploring Natural Inclusion] *[https://occurrity.com/ Occurrity] – The Art and Science of Natural Inclusion. *[http://www.naturalinclusion.org www.naturalinclusion.org] *[http://www.inclusionality.org www.inclusionality.org] *[http://www.inclusional-research.org www.inclusional-research.org] *{{cite book |last=Rayner |first=Alan |authorlink=w:Alan_Rayner |title=NatureScope|year=2012 |publisher=Earth Books |isbn=978-1846949807 |pages=198}} * [http://www.bestthinking.com/articles/arts_and_entertainment/art/paintings/i-opening?tab=article ''I - Opening''], Four paintings by Alan Rayner expressing awareness of self-identity as a dynamic inclusion of natural neighborhood. * [https://ia601506.us.archive.org/23/items/NaturalInclusionsPaintingsVol1/Natural%20inclusions%20Paintings%20vol1.pdf Natural Inclusions, Paintings Combining the Art and Science of Life], By Alan Rayner, Vol. 1, 1969 - 1999 * [https://ia801501.us.archive.org/10/items/NaturalInclusionsPaintingsVol2/Natural%20inclusions%20Paintings%20vol2.pdf Natural Inclusions, Paintings Combining the Art and Science of Life], By Alan Rayner, Vol. 2, 2000-2018 ==References:== <references/> [[Category:Applied Wisdom]] [[Category:Nature]] [[Category:Clear Thinking]] [[Category:Courses]] {{Clear Thinking}} 6ld2o1it6t7a7b9xgupfjxown96daxw 2414056 2414038 2022-08-13T08:41:48Z Fehufanga 2860899 Undo revision 2414038 by [[Special:Contributions/41.116.254.192|41.116.254.192]] ([[User talk:41.116.254.192|talk]]) not really helpful wikitext text/x-wiki —Learning to experience the world ''from'' nature<br> [[File:Ripple effect on water.jpg|thumb|right|300px|Notice how the [[Natural Inclusion/space|space]] of the water receives the energy of the waves. ]] {{TOC right | limit|limit=2}} Perhaps the way we have been taught to look at the world makes it difficult to see its true nature. By focusing on objects, definitions, and static representations of the world we have overlooked flows, connectivity, cohesiveness, and the intrinsically dynamic nature of the world. Fortunately we can learn to see through the illusion of dichotomies and definitions that has occluded our view of connectivity, [[Natural Inclusion/space|space]], energy, dispersions, and flow. Gaining this new perspective, we can then apply it to meeting the [[Grand challenges]]. The objectives of this course are to: *Meet the student where they now are in understanding that nature is intrinsically dynamic. *Examine the [[Natural Inclusion/space|space]], energy, [[Natural Inclusion/Boundaries|boundaries]], definitions, and flows of various natural systems. **Examine these elements from a variety of traditional perspectives. *Identify and explore the core concepts of Natural Inclusion. *See through the illusion of dichotomies and definitions that has occluded our view of connectivity, [[Natural Inclusion/space|space]], energy, and flow. *Understand that “All form is flow-form, an energetic configuration of [[Natural Inclusion/space|space]]”. *Relook at natural systems through the perspective of Natural Inclusion. *Apply the perspective of Natural Inclusionality to meet the [[Grand challenges]]. There are no specific prerequisites to this course, however, some students may find it helpful to complete the [[Global Perspective]] course before beginning this one. The website [http://www.spanglefish.com/exploringnaturalinclusion/ Exploring Natural Inclusion] provides an extensive collection of references on the topic. A [[Natural_Inclusion/glossary_of_terms|glossary of terms]] used in this course that are new, unusual, or that are being used in unusual ways is provided to help the student grasp the course content more easily. Direct links to key concepts in the course are gathered in the [[Natural_Inclusion#Quick_Links|quick links]] section. This course is part of the [[Wisdom/Curriculum|Applied Wisdom curriculum]]. == Becoming Receptive == Each of us arrives here with our own unique background, experience, beliefs, and expectations. Some of this background will make us receptive to the new concepts of Natural Inclusion; other background will make it difficult to grasp these ideas. Please complete the following exercises to help identify and overcome various illusions that may be occluding your view of the world, and to begin your introduction to Natural Inclusion. === Dismissing False Dichotomies === Often we describe our world in terms of this or that, black or white, right or wrong, true or false, good or bad, heaven or hell, liberal or conservative, prosecution or defense, guilty or innocent, and other stark scenes of opposition. These distinctions often create false dichotomies that exclude fertile middle ground or other alternatives where creative solutions often reside. ==== Assignment ==== #Read this short [http://www.emotionalcompetency.com/distortions.htm#Pole essay on polarized thinking]. #Identify examples of polarized thinking, false dichotomies, false choices, or excluding middles that you perpetuate with your own language. #Recast your thinking and language to become more inclusive and more accurately characterize the full scope of what is. === Transcending Conflict === We regularly face conflict as we encounter contradictory goals. Too often we focus on differences as we try to avoid the conflict, deny it, insist on getting our way, resign ourselves to abandon our own goals, or become consumed as we fight to the bitter end. These ineffective strategies are often the result of seeing only false dichotomies, and focusing on opposing alternatives rather than creating new solutions. Becoming more inclusive often allows us to see a better way. ==== Assignment ==== [[File:Conflict5.gif|thumb|Five Possible Resolutions.]] #Complete the course on [[Transcending Conflict]]. #Identify some conflict you are facing, avoiding, or resenting. #Identify the five distinct resolutions that are possible, as illustrated in the diagram shown on the right. #Which of these five outcomes is most desirable for all involved parties? What outcome can be reasonably achieved? What new idea or resource had to be included to allow this solution? === Seeing Through Illusion === {{100%done}}{{By|lbeaumont}} Each of us faces convincing illusions every day that distract us from seeing the full extent of what is. Perhaps the most pervasive and persuasive illusion is that what I see is all there is. To attain a perspective receptive to Natural Inclusion it is important to recognize these illusions and strive to see through them. ====Assignment==== #Read the essay [[Global Perspective/Toward a Global Perspective—seeing through illusion|Toward a Global Perspective—seeing through illusion]]. #Identify the illusions that you have recognized and overcome as you have learned more about the world. These may include childhood beliefs as simple as the Santa Claus and Tooth Fairy stories, or more significant misunderstandings about the diversity and scope of the world, its people, and the universe. What caused you to see through these illusions? How did your worldview change as a result? #What illusions do you not yet see through? What can you do to see beyond these and expand your perspective? ===Follow the Light Beam=== Choose a beautiful evening when you can enjoy this next assignment. ====Assignment==== #Carry a flashlight outdoors on a clear night. Turn it on, point the beam skyward, count to three, and turn the beam off. #Contemplate the journey of the light waves as they travel through space at nearly 300 million meters per second. #What is always ahead of the light beam (i.e. out in front of the leading surface of the light) as it speeds into space? #Repeat the experiment, and move the beam rapidly in a zigzag or figure eight pattern. Contemplate the movement of the beam as it travels through space. Where is it now? How far will it travel? How long is it? #Describe the boundaries of the light beam, where it is in space, and where the energy flows. ===Enjoying Nature’s Beauty=== The more closely we examine nature, the more fascinating its intricate beauty becomes. Also, the more aware we are of the beauty of nature, the more we are able to see. ==== Assignment: ==== '''Part 1:''' Notice everyday beauty as follows: # Watch the sunrise # Take a walk somewhere nearby. Notice each beautiful thing you see or hear. Make a list of this everyday beauty. Look closely. Look closer. # Savor the beauty in your life. '''Part 2:''' Practice [[w:Miksang|''miksang'']]—good eye—as follows: # Read the article “[http://www.miksang.com/miksang.html What is Miksang]?” # Read the article “[http://www.alternativemedicine.com/beginners-mind/turn-lens-toward-your-life Turn a Lens Toward Your Life]”. # Follow the guidance given in the section “Capture the Moment” Note, no camera is necessary. The essence of the technique is in noticing the beauty. # Practice miksang aurally. Notice pleasant sounds such as song birds, running water, or children playing. (Evaluate the book ''The Old Ways: A Journey on Foot'', by Robert Macfarlane to include here as recommended reading.) ===Bubbles as Flow-Forms=== Enjoy watching this video of [http://www.youtube.com/watch?v=SpnuaQqzlQc Soap Bubbles Shrinking in Slow Motion], a demonstration of Partial Coalescence. [[File:Girl blowing bubbles.jpg|240px|thumb|Bubbles, space, flow, neighborhood, and community.]] ====Assignment:==== After watching the video, please answer these questions. #Can you describe a [[w:Soap_bubble|bubble]] without mention of the space within its volume? What does a bubble include? #Beginning 15 seconds into the video, how are the new bubbles created inside of the large bubble? Where do baby bubbles come from? #Consider the boundary of a particular bubble. Does that boundary separate the bubble interior from space, or does it separate space from the bubble interior? #When two bubbles merge (coalesce) describe what happens to the boundaries of each, and to the space encapsulated by each. Which of the two bubbles lives, and which one dies? #Bubbles change shape to minimize energy expenditure. For a bubble to persist, its primary need is to attune its activities and development to correspond with energy availability and hence with the local conditions of its environment. It is therefore clear that the availability of sources of energy is the principal influence that governs the growth, organization and function of these bubbles.<ref name="spacecut"> ''[http://link.springer.com/article/10.1007%2Fs12124-011-9154-y#page-2 Space Cannot Be Cut—Why Self-Identity Naturally Includes Neighbourhood]'', Alan David Rayner, Integr Psych Behav (2011) 45:161–184. </ref> #Can a bubble form independent of space? #Can a bubble form independent of energy? #Can a bubble exist independent of its neighborhood? A type of green algae, called ''[[w:volvox|volvox]]'', forms large spherical colonies. These form much like the bubbles in the above video, as can be seen in this video showing the [https://www.youtube.com/watch?v=nipgwvkx5-s middle and late reproductive stages of the volvox life cycle] and this video on [https://www.youtube.com/watch?v=cmSs157KvTg Sexual Reproduction in Volvox]. After watching these videos, answer the questions posed above substituting volvox for bubbles. Now, sit back, relax, and enjoy watching this [https://www.youtube.com/watch?v=27XvZReW_cs&NR=1&feature=endscreen lava lamp video]. Where is the space, where is the energy, where are the boundaries? ===Examining Plant Life=== Dr. [[w:Alan_Rayner|Alan Rayner]], an originator and primary authority on Natural Inclusion, was originally trained as a botanist. He developed key concepts from his observations of germination, growth, propagation, metabolism, and death of various plant forms. On February 13, 2013, he gave a lecture on The Art and Science of Understanding Plant Life at the [[w:Bath_Royal_Literary_and_Scientific_Institution|Bath Royal Literary and Scientific Institution]]. ====Assignment==== #Watch the video of his talk “[http://www.youtube.com/watch?v=fY04y8P0zwE The Art and Science of Understanding Plant Life]” #Describe the flows that sustain a tree #Describe a tree as a dynamic system. Be sure to describe various flows occurring on time scales of minutes, months, and years. ==Choosing Your Path== In his book ''[http://www.inclusional-research.org/inclusionalnature.php Inclusional Nature, Bringing Life and Love to Science]'' Dr. Alan Rayner describes the context, life circumstances, and evolving thought that led him to imagine, refine, describe, and pioneer the concepts of Natural Inclusion. He describes the path his journey is taking from the traditional thinking of ''abstract rationality'' to Natural Inclusion. With his insights now accessible through his writing, painting, and lecturing, we can each follow our own various paths to understanding Natural Inclusion. Many students may already be proficient in some traditional discipline, or have extensive background in some area. In this section of the course we begin with that background, and provide a path from your existing specialized background toward the core concepts of Natural Inclusion. Please scan the list of paths provided below, and choose at least one to follow that best matches your background or interest. For other paths, browse the various [http://www.inclusional-research.org/streams.php Inclusional Research Streams]. ===A Youngster's Path=== Young hearts and minds may be particularity open to grasping the concepts of Natural Inclusion, as in this imaginary dialogue: [http://www.bestthinking.com/articles/lifestyle/natural-inclusion-for-the-young-of-heart-and-mind Natural Inclusion for the Young of Heart and Mind]. ===An Engineer’s Path=== The gateway concept for an engineer to grasp is considering the world as a collection of [[w:System_dynamics|dynamic systems]]. If you have an engineering background, please read this essay: An Engineer’s Journey (currently in preparation). ===A Business Person's Path=== In the article [http://thenatureofbusiness.org/2013/11/01/from-natural-exclusion-to-natural-inclusion/ ''From natural exclusion to natural inclusion''], Giles Hutchins encourages businesses to learn from nature, reconsider the true nature of relationships and trade boundaries, broaden the scope when considering costs and benefits, and include all ''that is''. ===An Ecologist’s Path=== See: http://www.inclusional-research.org/biology.php ===A Philosopher’s Path=== See: http://www.inclusional-research.org/philosophy.php ===A Natural Scientist’s Path=== See: http://www.inclusional-research.org/physics.php ===A Theologian’s Path=== See: http://www.inclusional-research.org/theology.php ===A Spiritual Path=== See: http://www.inclusional-research.org/theology.php ===A Psychologist’s Path=== See: http://www.inclusional-research.org/psychology.php ==Observing the Natural World== With a deeper understanding of concepts forming a foundation for Natural Inclusion, we are ready to examine the flows occurring in a variety of important natural systems. ===Flows in Natural Systems=== While [[w:Engineering_drawing|engineering drawings]], diagrams, photographs, and even short-duration direct observations represent the world as stationary, natural systems are intrinsically dynamic. Consider these examples: [[Image:Water cycle.png|thumb|320px|Earth's [[w:Water_cycle|water cycles]] in ceaseless flows.]] *[[w:Universe#History_of_the_Universe|Formation of the Universe]] in time and space. Stars form, grow, explode and die. Galaxies are formed. Each of the chemical elements is formed. *Hydrology, fluid mechanics, calculus, engines, mechanical devices, electromagnetic waves, and alternating current are inherently dynamic. *All forms of [[w:wave|waves]] including surf, sound, light, and earthquakes are inherently dynamic; an extensive form of energy distributed in space. *Plants grow, live, breath, die and decay. *The [[w:Citric acid cycle|citric acid cycle]], [[w:Calvin cycle|Calvin cycle]], [[w:nitrogen cycle|nitrogen cycle]], and [[w:Carbon cycle|carbon cycle]] are all essential flows sustaining life on earth *Animals are conceived, grow, eat, breath, live, die and decay. * [[w:Ecosystem|Ecosystems]] are characterized by complex and dynamic relationships involving primary production, energy flows, decomposition, nutrient cycling, a range of function and biodiversity, and many ecosystem goods and services. *[[w:Continental_drift|Continents drift]], mountains are formed, rocks flow, earthquakes shake, wind blows, rain falls, water erodes, silt and dust drift. *[[w:Ocean_current|Ocean currents]] flow, tides ebb and flow, waves propagate, undulate and crash, beaches erode, barrier islands form and reform. *Weather describes continuous changes in temperature, pressure, humidity, winds, clouds, rain, snow, sleet, and hail. Clouds form, rain falls, streams and rivers flow. *Climates describe long term variations in weather patterns in time and space. *[[w:Storm|Storms]] form, winds blow, rain falls, lightning strikes, oceans surge, water rises, trees fall. *We are each conceived, gestate, are born, breath, eat, sleep, defecate, grow, learn, work, play, mate, age, die, and decay. *Elements combine, dust clouds drift, gravity receives, solar systems emerge, [[w:Nebular_hypothesis|planets form]], revolve, and rotate; [[w:Abiogenesis|life emerges]]. “Essentially, all models are wrong,” [[w:George_E._P._Box|George Box]] noted, “but some are useful.” Since the systems of the natural world are intrinsically dynamic, rather than static, these systems are better described using dynamic rather than static models, using language that emphasizes movement and flow rather than artificially imposing some static snapshot of the system. Also, neither the [[w:Reductionism|reductionism]] approach nor the [[w:Holism|holism]] approach to modeling nature is entirely effective. Natural Inclusion reconciles these two dichotomies and provides [[Natural_Inclusion/modeling|an inclusive approach to modelling nature]]. ==The Core Concepts of Natural Inclusion== We are now ready to briefly describe the core concepts of Natural Inclusion. '''Natural Inclusion''' is a radically new way of understanding '''evolutionary becoming''' as a process of '''cumulative energetic transformation''' or '''natural energy flow'''. Originally introduced by [[w:Alan_Rayner|Alan Rayner]], it applies to all scales of natural organization, from sub-atomic to cosmic, including '''biological [[w:Evolution|evolution]]'''. It arises from a '''core philosophical awareness''' of 'Natural Inclusionality', which recognizes that ''all form is flow-form, an energetic configuration of space''. This departs from '''definitive rationality''' in two fundamental ways. Firstly, natural [[Natural_Inclusion/Boundaries|boundaries]] are acknowledged to be ''intrinsically energetic'' 'dynamic interfacings' between distinct localities, not the 'inert limits' of discrete objects.<ref>Rayner, A.D.M.(1997), ''Degrees of Freedom - Living in Dynamic Boundaries''. London: Imperial College Press.</ref><ref name="Inclusionality">Rayner, A.D.M.(2004), ''Inclusionality and the role of place, space and dynamic boundaries in evolutionary processes''. Philosophica, 73, pp.51-70.</ref> Secondly, it is recognized that these natural [[Natural_Inclusion/Boundaries|boundaries]] can only be dynamic through the ''inclusion of space as infinite, intangible, frictionless presence''.<ref name="Inclusionality"></ref><ref name="spacecut"/><ref name="NaturesScope">Rayner, A.D.M.(2011b), ''NaturesScope: unlocking our natural empathy and creativity C an inspiring new way of relating to our natural origins and one another through natural inclusion''. O Books.</ref> Correspondingly, natural inclusion may be described as the ''co-creative, fluid dynamic transformation [[Natural Inclusion/modeling|of all through all]] in receptive spatial context''. An understanding of '''Natural Inclusionality''' can be gained from a wide variety of different viewpoints: philosophical, scientific, technological, mathematical, ecological, theological, artistic, educational, sociological, political, psychological, linguistic. By the same token, natural inclusionality has profound '''implications''' for a very wide variety of human endeavors and offers '''hope''' for resolution of some of the most intractable human '''problems''' and '''[[Grand_challenges|challenges]]''', which arise directly or indirectly from '''definitive rationality''' and that for thousands of years have resulted in profound '''conflict''' and '''suffering'''. Alan Rayner describes and illustrates these concepts in [http://youtu.be/8CGvQX3eNjI this short video]. === Art and Creativity === Artistic approaches can both be inspired by and help to develop and communicate inclusional perceptions of receptive space and dynamic boundaries, which can transform our understanding of evolutionary processes in biological, ecological, geological, cosmic and social systems. Lyrical writing, visual and performance art are very effective means of exploring these perceptions in an invitational and immediate way that can, without imposition, engage peoples' imagination and go beyond the restrictions of definitive language. Inclusionally, all patterns and processes in nature arise from the variable stiffening and yielding of fluid dynamic, spatial-informational medium (flow-form). Excessive stiffening results in the rigidity of 'fixed' or 'frozen' form, corresponding with the static linearly boxed (3-dimensional) and excluded space of [[w:Euclidean_geometry|Euclidean geometry]]. Excessive yielding results in formlessness. Correspondingly, creativity dynamically mixes informational rigidity (discipline) with spatial relaxation (letting go) so as to generate and explore an infinite array of possible forms of expression ('formings'). Any meaningful work of [[w:Art|art]] hence depends upon being both relaxed enough and disciplined enough to allow expression to flow into forming. This is when the [[w:Muse|Muse]] works her magic in the [[w:Liminality|liminal zone]] between conscious and unconscious realms in a way that can seem little short of miraculous when we become ‘[[w:Writer's_block|stuck]]’ between periods of creativity. The inhibition felt when the 'blank canvas', 'blank page', ‘block of wood, stone, metal or clay, and 'pregnant silence' freezes us into non-expression is like what happens when trying to swallow at will. As soon as we concentrate on the action or intention itself, our throat locks up - analysis becomes paralysis. To proceed at all, it is necessary to have the courage to 'let go' in an act of faith that all will or at least can be well. But the letting go has to be constrained if it is not simply to splurge. Ultimately the combined sense of having the courage to relax and allow whatever comes to mind or hand to emerge and surprise, along with the determination to maintain influence over what issues forth can fill with deep excitement, pleasure and awe - just as Nature does - on a good day. On a day and in a place where those defensive 'blocks' that paralyze so much of modern culture don't get in the way of our joyful expression. When we have the sense of being lovingly receptive—responsive channels, not grudgingly possessive, active-reactive authors demanding royalties for what flows through us from beyond our local reach. === Language and Linguistics === Definitive language reinforces definitive theory and practice in ever more intractable cycles. Hence whenever language is regarded as more than an aid to communicating our meanings and experiences, and acquires some kind of life of its own as our sole means of expression, it is a trap. We become entangled in a web of misunderstandings and arguments over exact meanings, where we desperately seek uniformity of usage to avoid ambiguity. But such uniformity runs counter to the rich variety and evolutionary possibility of life. We can gain such uniformity only through not being able to express our appreciation of what living really means in all its dynamic depth and complexity. By restricting our communications to what can be articulated explicitly, we leave aside, out of sight and out of mind, the enormity of implicit experience. Through inclusional awareness it may not only be possible to recognize this language trap but also to find ways of avoiding it. Firstly, we can use language and metaphors that tend to sustain fluid possibility and don’t reinforce concepts of definitive closure. For example, we can use the language of water, not the language of concrete in our descriptions of life and evolution. Secondly, through appreciating how the meaning of words is influenced, sometimes radically, by the context in which they are being used, we can make clear that the context is inclusional. The meaning of ‘information’, for example, is definitive when used in a rationalistic context, but dynamic relational in an inclusional context. Use [http://www.emotionalcompetency.com/dialogue.htm dialogue], rather than a more [http://www.emotionalcompetency.com/tone.htm polarizing form of communication] whenever possible. More on inclusional language, including suggested alternative word choices, is provided in this [http://www.inclusionality.org/index.php?option=com_content&view=article&id=6&Itemid=15 article on inclusional language]. === Principles === The '''intention''' of this course is to explore the meaning and implications of natural inclusion from these diverse viewpoints. But before setting out on this exploration, it is worth pointing out that in order to understand the '''basic principles''' of natural inclusionality, it is ''not necessary'' to have extensive prior knowledge, and indeed this can be an obstacle because the way we have predominantly taught ourselves to think over the last few thousand years actually profoundly contradicts the way we naturally are in the world as it naturally is as flow-forms - energetic configurations of [[Natural Inclusion/space|space]]. All we '''actually''' have to do to understand these basic principles is to ask ‘what needs to be present for natural form to be distinguishable?’ Or, more concretely, ‘why is our direct experience of walking into a brick wall different from that of walking through an open doorway?’ Or, ‘what makes it possible to paint a picture?’ It then becomes apparent that the only way of answering these questions is to acknowledge the occurrence of ''at least'' two kinds of natural presence: a ''receptive context'' or medium which provides ''freedom for local movement and/or expression'', '''and''' ''local formative content'', which ''informs'' or ''configures'' that context. The former is necessarily ''spacious'', the latter necessarily ''cohesive''. Moreover, for form to be and become distinguishable, each of these presences must naturally include the other. Spacious presence alone would be formless void, and formative presence alone would have no shape or size. They are necessarily distinct, but mutually inclusive presences. They can neither be abstracted from one another as independent entities, nor be homogenized into ‘Oneness’. The only way in which this necessity can be fulfilled is for one of these presences, natural [[Natural Inclusion/space|space]], ultimately to be ''everywhere'', continuous, intangible (i.e. frictionless) and immobile, and for the other ultimately to be ''somewhere'', distinctive, tangible and ''continually'' in motion. Natural [[Natural Inclusion/space|space]] and figural [[Natural_Inclusion/Boundaries|boundaries]] are hence, respectively, ''continuous'' and ''dynamically distinct'' (i.e. dynamically continuous) ''energetic interfacings'' between the insides and outsides of all natural forms as ''flow-forms''.<ref name="Inclusionality"></ref><ref name="spacecut"/><ref name="NaturesScope"></ref> The natural world is better understood and described by focusing on: *'''Energy'''—the presence of mobility, *'''[[Natural Inclusion/space|Space]]'''—the continuous, immobile, intangible presence that becomes configured and reconfigured into distinctive localities by natural energy flow. Read this in-depth discussion of [[Natural Inclusion/space|space]] for a deeper understanding of this concept. *'''Flow'''—continuous change in locality, *[[Natural_Inclusion/Boundaries|'''Boundaries''']]—energetic interfacings. Read this in-depth discussion of [[Natural Inclusion/Boundaries|boundaries]] for a deeper understanding of this concept. * [[Natural_Inclusion/modeling|'''Each in the Other''']] — recognizing that [[Natural Inclusion/space|space]] permeates [[Natural Inclusion/Boundaries|boundaries]]. Rejection of [http://www.emotionalcompetency.com/distortions.htm#Pole false dichotomies]. *'''Dispersions'''—complex flows distributed in space and time, and *'''Flow-forms'''—localities of flow Explore! ====Assignment==== #Choose some natural system of flows. This might be chosen from the section “[[Natural_Inclusion#Flows_in_Natural_Systems|Flows in Natural Systems]]” above, or from some other source. #Describe the system in terms of the energy, [[Natural Inclusion/space|space]], flow, [[Natural Inclusion/Boundaries|boundaries]], flow-forms, and [[Natural_Inclusion/modeling|each in the other]]. ==All form is flow-form, an energetic configuration of space== In general terms, natural inclusionality is a kind of awareness that helps us to appreciate our selves and other tangible forms as dynamic inhabitants of Nature, not discrete subjects and objects rigidly set apart from one another.<ref>[http://www.bestthinking.com/articles/science/biology_and_nature/ecology/inclusional-sustainability Inclusional Sustainability: A Natural Way of Life], by Alan Rayner, BestThinking, </ref> At the heart of inclusionality is a simple but radical shift in the way we frame reality, from ''absolutely fixed'' to ''relationally dynamic''. This shift arises from perceiving [[Natural Inclusion/space|space]] and [[Natural_Inclusion/Boundaries|boundaries]] as connective, reflective and co-creative, rather than severing, in their vital role of producing heterogeneous form and local identity within a featured rather than featureless, dynamic rather than static, Universe.<ref>''[http://www.inclusional-research.org/inclusionalnature.php Inclusional Nature, Bringing Life and Love to Science]'', by Alan Rayner </ref> The ''simple move from regarding [[Natural Inclusion/space|space]] and [[Natural_Inclusion/Boundaries|boundaries]] as sources of discontinuity and discrete definition to sources of continuity and dynamic distinction'' is the ecological and evolutionary point of departure of ‘natural inclusionality’ from objective rationality.<ref name="spacecut"/> By acknowledging ourselves as distinct but not isolated local inclusions of natural energy flow, it is always possible gracefully to accept what we receive, to nurture and make the best of it, eventually to pass it on.<ref name="spacecut"/> Alan Rayner summarizes the idea succinctly: "Think of it this way - by imaginatively contemplating the question of what makes any natural form distinguishable from its surroundings? It becomes apparent that the only way of answering this question is to acknowledge the occurrence of ''at least'' two kinds of natural presence: ''a receptive context'' or non-resistive medium, which provides ''freedom for local movement and/or expression'', AND ''local formative content'', which ''informs'' or ''configures'' that context. The former is necessarily ''spacious'', the latter necessarily ''cohesive''. Moreover, for form to be and become distinguishable, ''each of these presences must naturally include the other''. Spacious presence alone would be formless void, and formative presence alone would have no shape or size. They are necessarily distinct, but mutually inclusive presences. They can neither be abstracted from one another as independent entities, nor be homogenized into ‘Oneness’. The only way in which this necessity can be fulfilled is for one of these presences, natural space, ultimately to be ''everywhere'', continuous, intangible (i.e. frictionless/non-resistive) and immobile, and for the other ultimately to be ''somewhere'', distinctive, tangible and ''continually'' in motion. Try whirring your hand around in front of your face until it appears as a blur, and you may get a feel for how all distinguishable form will ultimately appear this way when viewed sufficiently closely (i.e. at sufficient magnification) and for sufficient duration - if the whirring stops even for a moment, so too does 'time', and the mutual inclusiveness of each in the other breaks down irretrievably. Natural space and figural boundaries are hence, respectively, ''continuous'' and ''dynamically continuous energetic interfacings and distinctions between the insides and outsides of all natural forms as flow-forms.''" He goes on to say: "Whenever I see a contradiction between two supposed opposites, I feel there must be a deeper way to consider them that will reveal an underlying need of each for the other. Whenever I see a pattern in some phenomenon or concept (historic or contemporary), I automatically and intuitively notice resemblances to some other phenomenon or concept. I do this with wildlife, with science, with writing, with art, and seemingly every other area of interest that has fired my imagination over the decades. I simply cannot avoid doing that, and wouldn't want to. Once I called it 'looking for connections', until I realized that language didn't evoke the right image in my mind. Nowadays, I would call it 'looking for affinities'. This is why I have come to regard 'evolutionary ecology' - the study of pattern, process and relationship at any scale, the most basic of all forms of NATURAL scientific enquiry." ===A Fresh Look at Natural Systems=== ===Putting Natural Inclusionality into Practice=== "We must draw our standards from the natural world. We must honor with the humility of the wise the bounds of that natural world and the mystery which lies beyond them, admitting that there is something in the order of being which evidently exceeds all our competence." --[[w:Vaclav Havel|Vaclav Havel]], president of the Czech Republic Reconceiving many of our social and political institutions and basing them on the principles of Natural Inclusion provides new solutions. Here are some examples. ====In Design==== [[File:Leaf_1_web.jpg|thumb|right|300px|Flows create form in flow-form networks.<ref> [http://www.actionresearch.net/living/tesson.shtml ''Dynamic Networks, An interdisciplinary study of network organization in biological and human social systems'']., Karen June Tesson, Doctoral Dissertation, University of Bath, Department of Psychology, June 2006 </ref> ]] Nature itself is the greatest master of Natural Inclusion. [[w:Biomimicry|Biomimicry]] pioneer [[w:Janine_Benyus|Janine Benyus]] encourages designers to ask “How would nature solve this problem?” and then observes “Learning ''about'' the natural world is one thing, learning ''from'' the natural world—that’s the switch. That’s the profound switch.”<ref>[http://www.ted.com/talks/janine_benyus_shares_nature_s_designs.html Janine Benyus: The promise of biomimicry], TED Talk</ref> [[w:Biomimicry|Biomimicry]] is the examination of nature, its models, systems, processes, and elements to emulate or take inspiration from in order to solve human problems. In many natural systems local configurations based on energy balance lead to efficient, enduring designs where essential [[w:Emergence|properties emerge]]. Design paradigms based on [[w:Self-organization|self-organization]] and local context contrast with the typical top-down, central control-oriented design of so many human-designed systems. Examples include ant colonies, bee colonies, flocks of migrating birds, animal skins, leaves, insect anatomy, water flows, healing mechanisms, microscopic surface features, solar energy capture, wind energy capture, membranes, fibers, colors without pigments, parallel processing, lightweight structures, and strong materials. There are many [[w:Patterns_in_nature|patterns in nature]]. Natural systems are successful; they have proven their ability to survive—some species are billions of years old—through a range of environmental conditions. “We live in a competent universe.”<ref>Janine Benyus: [http://www.ted.com/talks/janine_benyus_biomimicry_in_action.html Biomimicry in action], TED Talk</ref> Often success is based on remarkably efficient approaches to capturing and using energy. These solutions evolved in context. “Life creates conditions conducive to life.” Designers who have looked to nature for inspiration have developed elegant solutions to difficult problems. Studying natural flows inspired these innovative products: The [http://www.aquaporin.dk/ AQUAporin] company is creating a new class of water filtration membranes based on [[w:Aquaporins|aquaporins]]—a naturally occurring protein central to the functioning of Human kidneys— as cornerstones in water filtering devices to be employed in industrial and household water filtration and purification. These filters, based on flows and [[Natural_Inclusion/Boundaries|boundaries]] in the human kidney, can play a role in making fresh water more widely available. [http://www.biopowersystems.com/ BioPower Systems] is developing bioWAVE^TM units to provide utility-scale electric power production from ocean waves. Its design, inspired by aquatic plants, combines high conversion efficiency with the ability to avoid excessive wave forces, enabling supply of grid-connected electricity at a competitive price per [[w:Kilowatt_hour|megawatt hour]]. The [http://www.paxscientific.com/ PAX Scientific] product design firm has designed a more efficient [[w:impeller|impeller]] and [[w:turbine|turbine]] based on recurring natural patterns of [[w:Vortex|vortical flow]]. Inspiration came in part from studying the spiral movement of kelp in response to water movement. Designing the front of a high-speed train based on the [[w:kingfisher|kingfisher’s]] beak allows more efficient transitions through the air pressure difference encountered when entering a tunnel at high speeds. This allows the [[w:Shinkansen|Shinkansen]] Bullet Train to run more quietly while requiring less energy.<ref> [http://www.biomimicryinstitute.org/case-studies/case-studies/transportation.html Learning Efficiency from Kingfishers]</ref> =====Assignment===== #Watch at least one of these videos on biomimicry: ##Janine Benyus: [http://www.ted.com/talks/janine_benyus_shares_nature_s_designs.html The promise of biomimicry] ##Janine Benyus: [http://www.ted.com/talks/janine_benyus_biomimicry_in_action.html Biomimicry in action] ##Michael Pawlyn: [http://www.ted.com/talks/michael_pawlyn_using_nature_s_genius_in_architecture.html Using nature's genius in architecture] #Browse the design solutions shown in this [http://www.asknature.org/product/highlight/NYSERDA+Energy gallery of products]. #Identify at least one specific [[w:Biomimicry|biomimicry]] approach and describe how it can address a particular [[Grand challenges|Grand Challenge]]. # You may also be interested in this related video on self-assembly technology. Skylar Tibbits: [http://www.ted.com/talks/skylar_tibbits_the_emergence_of_4d_printing.html The emergence of "4D printing"]. ====In Economics==== Traditional [[w:Economics|economics]] is based on several assumptions that exclude, rather than include nature. The value of [[w:Natural_capital|natural assets]], especially [[Limits_To_Growth#Ecosystem_Services|ecosystem services]], is typically ignored in financial calculations. Although these services are essential, we rarely account for their value in our economic models. For example, pollination of crops by bees is required for 15-30% of U.S. food production, yet the services of the bees themselves (as distinct from beekeeping activities) are regarded as free. One study estimates the value of ecosystem services world-wide at approximately $33 trillion per year. A similar example is the way in which extracted minerals, such as oil, is accounted for. Although the oil itself has value, even before it is discovered and extracted, financial systems attribute value primarily after it is extracted. An inclusive accounting system would treat petroleum sales as liquidation of a capital asset, rather than as income. It is important to distinguish between ''economies''—the exchange of goods and services—and ''economics''—a money-based model of an economy. “Essentially, all models are wrong,” [[w:George_E._P._Box|George Box]] noted, “but some are useful.” Unfortunately the models we use in our financial accounting systems diverge significantly from a value-based economy. Perhaps asking "what else is happening" can help draw your attention away from the narrow financial transaction to notice the full extent of the economic exchange, both positive and negative, that is taking place. Traditional economics relies on several premises which are clearly false: #Growth can continue indefinitely, #[[w:Externality|Externalities]] can be safely ignored, #Natural resources represent income that increases as they are extracted rather than capital which depreciates as it is depleted, and #Resources can be substituted for one another with infinite flexibility.<ref>{{cite book |title=The End of Growth: Adapting to Our New Economic Reality |last=Heinberg |first=Richard |year=2011 |publisher=New Society Publishers |isbn=978-0865716957 |pages=336}}</ref> In contrast, an inclusive economic model would: #Acknowledge [[Limits To Growth|limits to growth]], #Account fully for [[w:Externality|Externalities]], #Treat natural resource extraction and consumption as liquidation of a [[w:Capital_(economics)|capital resource]], #Recognize that many resources are unique. The emerging fields of [[w:Ecological_economics|ecological economics]] and [[w:Environmental_economics|environmental economics]] begin to address these issues. =====Assignment===== How do you prefer to spend a day? Perhaps you would enjoy hiking with someone through the local county park, seeing the natural beauty, listening to the sounds of nature, and noticing some wildlife while getting healthy exercise and strengthening a friendship. Alternatively you might enjoy a day at Disney World, mingling with the crowds, enjoying amusement rides, and meeting the Disney characters. While these two options may have similar value to you, the first costs little or nothing, and the second costs plenty.<ref>[http://blog.grdodge.org/2012/06/25/time-is-money-so-take-it-to-the-bank-and-other-community-building-ideas/ Time is Money, So Take It to the Bank (and Other Community Building Ideas)], Leland R. Beaumont, The Dodge Blog, June 25, 2012</ref> #If the county park and [[w:Walt_Disney_World|Disney World]] both charged admission, what relative charge do you think fairly represents the value of each experience? What do you think is a fair way to preserve the various [[w:Commons|commons]] we rely on? #Complete the assignment in the [[Limits_To_Growth#Ecosystem_Services|Ecosystem Services]] section of the Limits to Growth course. #Study the section on [[Global_Perspective#Externality|Externality]] (from the Global perspective course) and complete the assignment in that section. ====In Education==== With our understanding of Natural Inclusion the goal is for the student and teacher to enter a creative space where they can participate in co-creating a learning experience. [[w:Wikiversity|Wikiversity]] itself is an example of an inclusive learning environment. Because anyone can contribute to the creation, expansion, and improvement of course materials, energy of students and teachers is welcomed into the creative space of the courses. [[Help:Talk_page|Talk pages]] and other feedback channels help align students and teachers with the learning opportunities. There are many examples of [[w:Open education|open education]], each seeking to eliminate barriers to entry and increase student involvement. =====Assignment===== #Study this chart illustrating [http://www.thewisepath.org/papers/learning%20loop.pdf learning at the speed of thought]. #Identify a problem you would like to explore, pose a particular question you would like to answer, or identify some course of learning you would like to engage in. #Choose some [[w:Open_education|open education]] resource, perhaps within the [[w:MediaWiki|MediaWiki]] projects, or some other [[w:Open_education|open education]] resource. #Use the [[w:Open_education|open education]] resource to answer your question, move toward the solution of the selected problem, or pursue a course of learning. #Continue [http://www.thewisepath.org/papers/learning%20loop.pdf learning at the speed of thought] as you progress around the cycle. ====In Government==== Various forms of government, proposed and in practice, that seek to increase the involvement of more people in understanding issues, [http://www.emotionalcompetency.com/dialogue.htm dialoging] on concerns, proposing solutions, and making decisions are consistent with the general concepts of Natural Inclusion. Various forms of [[w:democracy|democracy]], especially including [[w:direct democracy|direct democracy]], and [[w:participatory democracy|participatory democracy]], are examples. A number of [[w:Transpartisan|transpartisan]] organizations strive to enter the space between polarized political positions, seek common ground, and offer new solutions. Transpartisanship acknowledges the validity of truths across a range of political perspectives and seeks to synthesize them into an inclusive, pragmatic container beyond typical political dualities. Such organizations include [[w:No_Labels|No Labels]], [[w:Coffee_Party|Coffee Party USA]], and [[w:FactCheck.org|FactCheck.org]] in the United States. The website [[w:openDemocracy.net|openDemocracy.net]] offers news and opinion articles covering current issues in world affairs. Using the slogan "Free thinking for the world", it seeks solutions that promote human rights and democracy, rather than advocating the traditional, polarizing ideologies. =====Assignment===== #Choose some issue to study that is deadlocked in debate between conservative and liberal politicians. If possible, choose one of the [[Grand challenges]] to focus on for this assignment. #Describe the conservative position on the issue. Describe the liberal position on the issue. #Adopt a point of view that transcends both the conservative and liberal positions to seek a solution that is best for the people being governed. Create alternatives for mutual gain. What creative, yet practical, solutions can you suggest? ====In Human Interplay==== No one can live while isolated from the environment. Physiologically we all need to breathe, drink, and eat, while we exhale, perspire, and excrete waste. We all consume energy to heat and cool homes, cook food, light spaces, and transport ourselves and our goods. Our [[w:Carbon_footprint|carbon footprint]] tries to take account of this need (and neediness). Socially, many of us crave human companionship, and feel bereft and powerless on our own. In short, we all benefit from ''participation''; engaging with others in our community to solve problems, manage our environment, and connect with each other to build, maintain and improve our [[What_Matters/Community|community]]. When we are able to [http://www.emotionalcompetency.com/self.htm#Detaching open up our egos], learn to co-create rather than compete, work together to protect the [[w:Commons|commons]], and appreciate both our similarities with our neighbors and our differences, this can certainly be [[What_Matters/Play|fun]] – and indeed profoundly inspiring. When we can attain and even transcend a [[Natural_Inclusion#Seeing_Through_Illusion|global perspective]], [[What_Matters/Compassion|feel compassion]], and become [[Virtues/Generosity|generous]], we all gain. =====Assignment:===== # Practice the skill of [http://emotionalcompetency.com/dialogue.htm dialogue], it is the art of ''participating'' in conversation. Use dialogue as a way to receive understanding from others, and allow them to receive understanding from you. #Read the module on [[What_Matters/Community|Community]] (from the What Matters course), and complete the assignments in that module. # Complete the course on [[Virtues|virtues]]. #Read the section on [[Limits_To_Growth#Ecological_footprint|Ecological Footprint]] (from the Limits to Growth course), and compete the assignment in that section. # Work to identify and include the various [[w:Externality|externalities]] you have been overlooking. Study the section on [[Global_Perspective#Externality|Externality]] (from the Global perspective course) and complete the assignment in that section. #What can you do to increase your participation and begin to address some of the [[Grand_challenges|Grand challenges]]? Do so. ====Land Use==== [[w:Wetland|Wetlands]], [[w:Coastal_geography|coastal regions]], [[w:Littoral_zone|littoral zones]], [[w:Barrier_island|barrier islands]], [[w:Waterway|waterways]], [[w:Fault_(geology)|earthquake zones]], [[w:Forest|forests]], and even [[w:desert|deserts]] are flow-forms; inherently dynamic land areas. Land [[w:deed|deeds]] use a static model to describe dynamic land forms, creating a fundamental mismatch. A new model of land ownership based on the dynamic nature of earth, water, climate, and weather is needed. (Are there any ideas here? Nomads lived dynamically, but the lifestyle seems difficult.) =====Assignment===== #Choose some [[w:Natural_disaster|natural disaster]] to study. This might be a flood, tsunami, blizzard, hurricane, typhoon, drought, heat wave, tornado, or wildfire. Major tragic events include: the [[w:Dust_Bowl|dust bowl]], the [[w:2004_Indian_Ocean_earthquake_and_tsunami|2004 Indian Ocean earthquake and tsunami]], [[w:Hurricane_Katrina|Hurricane Katrina]], the [[w:2011_Tohoku_earthquake_and_tsunami|2011 Tōhoku earthquake and tsunami]], climate change impacts on [[w:Climate_change_in_Tuvalu|Tuvalu]], and [[w:Hurricane_Sandy|Hurricane Sandy]]. #Describe how representing a flow-form with some static model contributed to the disaster. #To what extent are these tragedies the result of human error (an occluded view of the world) rather than truly natural? ====In Religion==== Imagine a religious belief system and forum that was centered on [[dignity]], universal [[w:Human_rights|human rights]], [[w:Fundamental_human_needs|human needs]], human [[w:Quality_of_life|well-being]], and [[w:Spirituality|spiritual]] longing, rather than on arbitrary religious [[w:Dogma|dogma]]. Imagine a religious organization that welcomed everyone because it honored the similarities of the needs and beliefs of the people, rather than excluding and opposing people who hold arbitrarily different beliefs. Imagine a safe space that welcomed inquiry, exploration, [[w:Skepticism|skepticism]], faith, and [http://emotionalcompetency.com/dialogue.htm dialogue] into the existential, spiritual, moral, and developmental questions we all have. Thoughtful and curious people open to experience and skeptical of the universal veracity of divine [[w:Revelation|revelations]] and sacred [[w:Scriptures|scriptures]] practice various forms of [[w:Nontheism|nontheism]] to meet their human and spiritual needs. =====Assignment===== #Read the [http://charterforcompassion.org/the-charter/ text] of the [[w:Charter_for_Compassion|charter for compassion]]. #Read the essay on [http://theycallmelee.blogspot.com/2010/11/from-destructive-dogma-to-constructive.html transcending dogma]. # Develop the [[Virtues/Tolerance|virtue of tolerance]]. Know its full extent and its limits. Practice tolerance. #Develop your own robust [http://emotionalcompetency.com/theoryofk.htm theory of knowledge] so you can be clear about why you believe what you believe. [[Knowing How You Know|Know how you know]]. # List existential, spiritual, or moral questions you seek guidance with. #Find an inclusive forum for exploring those questions and developing satisfactory answers. This might be discussions with a trusted friend or mentor, research into theories on the [[w:Cosmogony|origins of the universe]] and the [[w:Origins_of_life|origins of life]], study of [[w:Human_rights|human rights]] and [[virtues]], [[w:Contemplation|contemplation]], [[w:Introspection|introspection]], or [[w:Meditation|meditation]], some inclusive religious sect such as the [[w:Unitarian_Universalism|Unitarian Universalism]] church, [[w:Humanism|humanism]], or some other group more concerned with [[w:Spirituality|spirituality]] than [[w:Dogma|dogma]]. # Learn to [[Quiet Mind|quiet your mind]]. ==Meeting the Grand Challenges== The value of Natural Inclusion concepts can best be measured by their ability to improve overall well-being. How can an understanding of Natural Inclusion help us overcome the [[Grand challenges]]? The following table illustrates how Natural Inclusion concepts address the various Grand Challenges. The column headings are linked to the corresponding headings in this NI course, and the row labels are linked to the corresponding section in the [[Grand challenges]] course. Each cell entry describes how the Natural Inclusion approach addresses the corresponding Grand challenge. {| class="wikitable" |- ! NI Concept: !! [[Natural_Inclusion#In_Design|'''Design''']] !! [[Natural_Inclusion#In_Economics|'''Economics''']] !! [[Natural_Inclusion#In_Education|'''Education''']] !! [[Natural_Inclusion#In_Government|'''Government''']] !! [[Natural_Inclusion#In_Human_Interplay|'''Human Interplay''']] !! [[Natural_Inclusion#Land_Use|'''Land Use''']] !! [[Natural_Inclusion#In_Religion|'''Religion''']] |- |[[Grand_challenges#Physical_Health|'''Physical Health''']]|| Biomimicry Water Solutions|| Value Water Commons || || || || Preserve Ecosystems || |- |[[Grand_challenges#Mental_Health|'''Mental Health''']]|| || || || || Community participation improves mental health. || || Increased harmony reduces stress |- |[[Grand_challenges#Economic_and_Social_Opportunity|'''Opportunity''']]|| || More accurate accounting systems include more people. || Education increases opportunity || || || || Emphasis on human rights increases opportunity |- |[[Grand_challenges#Safety_and_Security|'''Safety''']]|| || || Education reduces crime and violence. || || Participation reduces violence and crime. || || Increased harmony reduces conflict. |- |[[Grand_challenges#Stability|'''Stability''']]|| || || || || Engage Across Classes and Hierarchies || || Increased harmony reduces conflict. |- |[[Grand_challenges#Environmental_Stewardship|'''Environmental Stewardship''']]|| Design efficiencies reduce resource consumption. || Value Environments, Value Eco Services, Value the Commons || Better understanding of environment’s value || || || Preserve Ecosystems || We are all stewards of the creation. |- |[[Grand_challenges#Government_Policy|'''Policy''']]|| || More accurate accounting reduces distortions. || Better informed policy makers. || Include more people in decision making. || Participation increases inclusion. || Improve land use utility. || Based on well-being rather than ideology. |- |[[Grand_challenges#The_Range_of_Opportunities:|'''Flourishing''']]|| Improved Aesthetics || Valuing the best things in life. || Education provides enrichment. || Government promotes well-being || Participation is enrichment. || Improved Aesthetics. || Continued spiritual growth. |} ====Assignment==== # Choose one cell in the above table to study in depth. # Describe in detail how the relevant NI approach addresses the corresponding grand challenge. # Create an action plan for using that approach to address the challenge. # Carry out that action plan. ==Quick Links== Direct links to key NI concepts are gathered here for easy access. * [[Natural_Inclusion/space|Space]]—the continuous, immobile, intangible presence that becomes configured and reconfigured into distinctive localities by natural energy flow. * [[Natural_Inclusion/Boundaries|Boundaries]]—energetic interfacings. Boundaries identify a shift between inner and outer contexts; boundaries face both ways. **[http://thewisepath.org/papers/Dynamic%20Interfacinged.pdf Dynamic Interfacing, the Vitality of Each in the Otherness], a slide presentation * Modeling Nature, [[Natural_Inclusion/modeling|Each in the Other]] — recognizing that space permeates boundaries ** Including [[Natural_Inclusion/modeling#Summaries|several summaries]] of this concept. * [[Natural_Inclusion/glossary_of_terms|Glossary of Terms]] ==Resources:== The resource materials listed here are useful for continued study of Natural Inclusionality. *[http://www.spanglefish.com/exploringnaturalinclusion/ Exploring Natural Inclusion] *[https://occurrity.com/ Occurrity] – The Art and Science of Natural Inclusion. *[http://www.naturalinclusion.org www.naturalinclusion.org] *[http://www.inclusionality.org www.inclusionality.org] *[http://www.inclusional-research.org www.inclusional-research.org] *{{cite book |last=Rayner |first=Alan |authorlink=w:Alan_Rayner |title=NatureScope|year=2012 |publisher=Earth Books |isbn=978-1846949807 |pages=198}} * [http://www.bestthinking.com/articles/arts_and_entertainment/art/paintings/i-opening?tab=article ''I - Opening''], Four paintings by Alan Rayner expressing awareness of self-identity as a dynamic inclusion of natural neighborhood. * [https://ia601506.us.archive.org/23/items/NaturalInclusionsPaintingsVol1/Natural%20inclusions%20Paintings%20vol1.pdf Natural Inclusions, Paintings Combining the Art and Science of Life], By Alan Rayner, Vol. 1, 1969 - 1999 * [https://ia801501.us.archive.org/10/items/NaturalInclusionsPaintingsVol2/Natural%20inclusions%20Paintings%20vol2.pdf Natural Inclusions, Paintings Combining the Art and Science of Life], By Alan Rayner, Vol. 2, 2000-2018 ==References:== <references/> [[Category:Applied Wisdom]] [[Category:Nature]] [[Category:Clear Thinking]] [[Category:Courses]] {{Clear Thinking}} a2lb6ez3jq5i6mmqh9752t6thw9nct8 6 156428 2414024 1145695 2022-08-13T04:32:16Z Marshallsumter 311529 /* Licensing */ wikitext text/x-wiki == Summary == A moreton wave is a kind of shock wave generated by solar flares on the Sun. Images acquired by Optical Solar Patrol Network (OSPAN) in H-alpha (656.3 nm). == Licensing == {{Information1 |Description=A Moreton wave is a kind of shock wave generated by solar flares on the Sun. Images acquired by Optical Solar Patrol Network (OSPAN) in H-alpha (656.3 nm). |Source=The image animation occurs in a Wikipedia entry, "Moreton wave" url=https://en.wikipedia.org/wiki/Moreton_wave. |Date=December 6, 2006. |Author=NSO/AURA/NSF and USAF Research Laboratory |Rationale = No free licensed or public domain alternatives known to exist to show a Moreton wave, a kind of shock wave generated by solar flares on the Sun. Images acquired by Optical Solar Patrol Network (OSPAN) in H-alpha (656.3 nm). |Permission=Fair use }} {{Fairuse}} telq99ne24k7f5pmjfsjzrw3jy03dnp 0 168889 2414002 1287076 2022-08-12T20:14:33Z 85.211.205.56 wikitext text/x-wiki The '''Cri du Chat''' ([[w:Cri du Chat]]) is a rare genetic disease in which caused by a missing piece of [[w:Chromosone 5|Chromosone 5]] (5p MonoSomy). The name came from the infant's crying, which is like a cat, and also high pitched ("Cri du Chat" is a French term, meaning "Cat Cry"). The disease was first discovered by [[w:Jérôme Lejeune|Jérôme Lejeune]] in 1963, in which is why it's also named ''Lejeune's Disease''. The cure for this disease is [[unknown]]. == Cure == * To help with communication skills, teach sign language for the child. * Speech Theropy, which can improve the poor language ability. * Physical Theropy, which can improve the poor muscle. === Get Help === * Your legal Doctor * Cri du Chat Support of Australia. (03) 9775 9962 * Association for Children with Disability. 03) 9818 2000 or 1800 654 013 * Better Start for Children with Disabilities. 1800 242 636 == Symptoms == * Drooling a lot * Unusual facial features, such as buck teeth. * Behavior, such as agression. * Big/Slanted Eyes * Rigid teeth * Flatten Nose and Small head. == Facts == *The disease becomes less noticeable as you grow up. *Girls get this disease more than boys == Sources == * http://www.nytimes.com/health/guides/disease/cri-du-chat-syndrome/overview.html * http://www.genome.gov/19517558 * http://emedicine.medscape.com/article/942897-treatment * http://rarediseases.info.nih.gov/gard/6213/cri-du-chat-syndrome/resources/1 * http://ghr.nlm.nih.gov/condition/cri-du-chat-syndrome/show/MedlinePlus * http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Cri_du_chat_syndrome * https://sites.google.com/site/criduchat304/extra-facts * http://www.newhealthguide.org/Life-Expectancy-Of-Cri-Du-Chat-Syndrome.html [[Category:Diseases]] [[Category:Genetics]] cncaqhoes1crttt93avq17l8f0f8tyr 1 170731 2413966 2413796 2022-08-12T14:36:48Z Athikhun.suw 2172981 /* Editorial board application of Athikhun Suwannakhan */ wikitext text/x-wiki <noinclude> {{WikiJournal editorial application top |archive box = {{Archive box|[[/Archive 2015-2017]] <br>[[/Archive 2018]] <br>[[/Archive 2019]] <br>[[/Archive 2020]] <br>[[/Archive 2021]] <br>[[/Archive 2022]] }} }} </noinclude> ==Associate editor application of James Bibey== {{WikiJournal editor application submitted | position =Associate editor | name =James Bibey | qualifications =2nd Year Medical Student | link =N/A | areas_of_expertise =General medicine (basic anatomy, physiology, biochemistry, statistics, ethics) | professional_experience =Maths lecturing, anatomical prosection preparation. | publishing_experience =N/A | open_experience =Significant editing history on English Wikipedia (primarily medicine and anatomy), Wikimedia Commons, and Wikidata under username "Bibeyjj". | policy_confirm =I confirm that I will act in accordance with the policies of the WikiJournal of Medicine. [[User:Bibeyjj|Bibeyjj]] ([[User talk:Bibeyjj|discuss]] • [[Special:Contributions/Bibeyjj|contribs]]) 19:23, 24 September 2021 (UTC) }} *{{Support}}. The applicant is [https://en.wikipedia.org/wiki/Special:Contributions/Bibeyjj active in related topics in Wikipedia], and I think we can really need the help for our journal too. [[User:Bibeyjj|Bibeyjj]], I hope you are still interested in this position. I'm sorry for the late response to your application, as you see we are quite busy with the everyday matters of the project. If elected, would you be willing to help out for instance in [[WikiJournal_of_Medicine/Editorial_guidelines#Arranging_peer_review|finding peer reviewers]] for article submissions to the journal? [[User:Mikael Häggström|Mikael Häggström]] ([[User talk:Mikael Häggström|discuss]] • [[Special:Contributions/Mikael Häggström|contribs]]) 19:10, 22 May 2022 (UTC) *{{Support}}. Mikael summarises the reasons well above and I agree [[User:Rwatson1955|Rwatson1955]] ([[User talk:Rwatson1955|discuss]] • [[Special:Contributions/Rwatson1955|contribs]]) 06:56, 23 May 2022 (UTC) *They seem a good candidate for assoc editor status, and it would be useful experience for them as well as helpful skills for us. We've been a bit stalled on applications over the last year, so it will be good to get organised again. [[User:Evolution and evolvability|T.Shafee(Evo&#65120;Evo)]]^{[[User talk:Evolution and evolvability|talk]]} 11:59, 11 June 2022 (UTC) :I agree. I made [https://en.wikipedia.org/wiki/User_talk:Bibeyjj#Associate_editor_application an entry on the user's talk page] whether he's still interested. If so, I think we can go ahead and approve this application. [[User:Mikael Häggström|Mikael Häggström]] ([[User talk:Mikael Häggström|discuss]] • [[Special:Contributions/Mikael Häggström|contribs]]) 15:52, 16 June 2022 (UTC) ::I haven't heard back from the wiki talk page, so I sent an email through the wiki system as well. [[User:Mikael Häggström|Mikael Häggström]] ([[User talk:Mikael Häggström|discuss]] • [[Special:Contributions/Mikael Häggström|contribs]]) 03:13, 2 August 2022 (UTC) ==Editorial board application of Daniel Barton Oerther== {{WikiJournal editor application submitted | position =Editorial board | Q = Q18001544 | name =Daniel Barton Oerther | qualifications =PHD | link =https://people.mst.edu/faculty/oertherd/ | areas_of_expertise =environmental health | professional_experience =Professor of environmental health engineering; Certified environmental health specialist and leader of a number of national and international organizations specializing in environmental health | publishing_experience =Editorial boards of Perspectives in Public Health, Water Environment Research, and Journal of Environmental Engineering ASCE | open_experience =Wikipedia and regular reviewer for open access Nursing Open | policy_confirm =I confirm that I will act in accordance with the policies of the WikiJournal of Medicine. [[User:Oertherdb|Oertherdb]] ([[User talk:Oertherdb|discuss]] • [[Special:Contributions/Oertherdb|contribs]]) 15:23, 25 February 2022 (UTC) }} *{{Support}}. The applicant has substantial credentials including health and leadership. [[User:Mikael Häggström|Mikael Häggström]] ([[User talk:Mikael Häggström|discuss]] • [[Special:Contributions/Mikael Häggström|contribs]]) 19:16, 22 May 2022 (UTC) *{{Support}}. I was the person who approached this candidate on the basis of his interesting background, enthusiasm for nursing and health and his Wikipedia experience [[User:Rwatson1955|Rwatson1955]] ([[User talk:Rwatson1955|discuss]] • [[Special:Contributions/Rwatson1955|contribs]]) 06:57, 23 May 2022 (UTC) *{{Support}}. [[User:Editor WikiJMed|Editor WikiJMed]] ([[User talk:Editor WikiJMed|discuss]] • [[Special:Contributions/Editor WikiJMed|contribs]]) 21:07, 23 May 2022 (UTC) *{{support}} - I also suppoprt this application (apologies for not noting earlier). I particular, they have a usefully interdisciplinary knowledgebase connecting medicine to engineering and environmental research. [[User:Evolution and evolvability|T.Shafee(Evo&#65120;Evo)]]^{[[User talk:Evolution and evolvability|talk]]} 11:56, 11 June 2022 (UTC) '''Result: Accepted into the editorial board.''' :[[WikiJournal_User_Group/Editorial_guidelines#Adding_editorial_board_members|Next steps]] (add <code>DONE</code> or <code><nowiki>{{Done}}</nowiki></code> after someone has performed the task): # {{Done}} [[{{ROOTPAGENAMEE}}/Editorial_guidelines/Message_templates#Onboarding_a_new_board_member|Send a welcome message and confirm their preferred email address]] (usually in their provided website link, else via [[Special:EmailUser]]) # {{Done}} {{clickable button 2 | url=https://en.wikiversity.org/wiki/{{ROOTPAGENAMEE}}/Editorial_guidelines/Message_templates#Onboarding_a_new_board_member|Onboarding email template}} # {{Done}} Copy their information over to [[{{ROOTPAGENAME}}/Editorial board|editorial board page]] using the {{tlx|WikiJournal editor summary}} template # __ Add their name and start data to the [[d:{{WJQboard|default=Q75674277}}|relevant editorial board]] on wikidata # {{Done}} Direct-add them to the {{WJX}}board mailing list ([https://groups.google.com/forum/?utm_medium=email&utm_source=footer#!managemembers/{{WJX}}board/add via this link]) which will grant them access to the private page only visible to board members # {{Done}} Welcome them at the {{WJX}}board mailing list so that they are informed # __ Finally, move the application to [[Talk:{{ROOTPAGENAME}}/Editors/Archive_{{CURRENTYEAR}}|this year's archive page]] ([[{{ROOTPAGENAME}}/Editorial guidelines/Message_templates#Onboarding_a_new_board_member|Suggested email template]])<br> [[User:Rwatson1955|Rwatson1955]] ([[User talk:Rwatson1955|discuss]] • [[Special:Contributions/Rwatson1955|contribs]]) 12:36, 13 June 2022 (UTC) ==Editorial board application of Luis Rafael Moscote-Salazar== {{WikiJournal editor application submitted | journal =WikiJournal of Medicine | position =Editorial board member | name =Luis Rafael Moscote-Salazar | qualifications =MD | link =https://neuroclani.org/ | areas_of_expertise =Neurosurgery, Neurotrauma, Stroke, Neurointervention, Neurocritical Care, Neurointervention, Evidence Based Medicine | professional_experience =Neurosurgeon graduated from the University of Cartagena, Founder of the Colombian Clinical Research Group in Neurocritical Care and Co-founder of the Latinamerican Council of Neurocritical Care (CLaNi). Research communication, research leadership, mentorship. | publishing_experience = Experience with publishing in peer-reviewed journals (see Google Scholar profile. Peer-reviewer for several international journals in Neurosurgery and Medicine (see Publons profile). | open_experience = | policy_confirm =I confirm that I will act in accordance with the policies of the WikiJournal of Medicine. [[User:NeuroQuimbaya|NeuroQuimbaya]] ([[User talk:NeuroQuimbaya|discuss]]) 2022-07-12 }} :No details were provided, so I have contacted the applicant to request that they add more information. [[User:Evolution and evolvability|T.Shafee(Evo&#65120;Evo)]]^{[[User talk:Evolution and evolvability|talk]]} 01:27, 7 July 2022 (UTC) ::I've updated the application above with the new replacement information that they sent through. [[User:Evolution and evolvability|T.Shafee(Evo&#65120;Evo)]]^{[[User talk:Evolution and evolvability|talk]]} 03:55, 13 July 2022 (UTC) :::'''Pending more specific presentation'''. I'm tending towards support, as the applicant seems active in research and publishing according to orcid ([https://orcid.org/0000-0002-4180-6962]). I think it is appropriate to let him join us. [[User:Mikael Häggström|Mikael Häggström]] ([[User talk:Mikael Häggström|discuss]] • [[Special:Contributions/Mikael Häggström|contribs]]) 03:12, 2 August 2022 (UTC) ::::[[User:NeuroQuimbaya|Dr. Moscote-Salazar]], some questions that have been raised are: ::::*Would you be able to provide a webpage or other presentation about yourself? The link provided (https://neuroclani.org/) directs to a more general website. ::::*Could you provide one or two sentences of what motivates you to join WikiJMed? ::::*Would you be willing to begin contributing as an associate editor? The tasks can be described here: [[WikiJournal_of_Medicine/Associate_editors]]. We feel we can really need some help with peer review coordination, and you'll have the opportunity to later become promoted to editorial board membership. ::::[[User:Mikael Häggström|Mikael Häggström]] ([[User talk:Mikael Häggström|discuss]] • [[Special:Contributions/Mikael Häggström|contribs]]) 02:11, 11 August 2022 (UTC) == Editorial board application of Athikhun Suwannakhan == {{WikiJournal editor application submitted | position =Editorial board | Q =Q87737627 | name =Athikhun Suwannakhan | qualifications =PhD | link =https://science.mahidol.ac.th/expertise/search.php?q=Athikhun%20Suwannakhan | areas_of_expertise =Clinical anatomy, medical imaging, medical education, systematic reviews and meta-analyses | professional_experience =Lecturer in Anatomy at Faculty of Science, Mahidol University, Bangkok | publishing_experience =As of August 2022, I have published [https://orcid.org/0000-0001-9910-0244 18 research articles] and peer-reviewed [https://publons.com/wos-op/researcher/1159692/athikhun-suwannakhan/ 50 times] for 12 journals. | open_experience =I am an advocate of the Wikimedia Movement and I have represented Wikimedia Thailand in various international Wikimedia events. | policy_confirm =I confirm that I will act in accordance with the policies of the WikiJournal of Medicine. -[[User:Athikhun.suw|Athikhun.suw]] ([[User talk:Athikhun.suw|discuss]] • [[Special:Contributions/Athikhun.suw|contribs]]) 00:23, 8 August 2022 (UTC) }} :'''Support'''. Athikhun Suwannakhan has extensive experience both in medicine-related fields, as well as wiki contributions. He has helped out with peer reviews, such as for the [[WikiJournal of Medicine/The Cerebellum|Cerebellum]] article back in 2016, so I feel he's already shown enough helpfulness for editorial board membership. [[User:Mikael Häggström|Mikael Häggström]] ([[User talk:Mikael Häggström|discuss]] • [[Special:Contributions/Mikael Häggström|contribs]]) 01:49, 11 August 2022 (UTC) *{{Support}}. I agree with Mikael's assessment [[User:Rwatson1955|Rwatson1955]] ([[User talk:Rwatson1955|discuss]] • [[Special:Contributions/Rwatson1955|contribs]]) 13:15, 11 August 2022 (UTC) 5ft380vquzff7gm6pm3j3txydjtiwaa 0 171005 2413958 2413334 2022-08-12T14:05:15Z Young1lim 21186 /* Geometric Series Examples */ wikitext text/x-wiki Many of the functions that arise naturally in mathematics and real world applications can be extended to and regarded as complex functions, meaning the input, as well as the output, can be complex numbers <math>x+iy</math>, where <math>i=\sqrt{-1}</math>, in such a way that it is a more natural object to study. '''Complex analysis''', which used to be known as '''function theory''' or '''theory of functions of a single complex variable''', is a sub-field of analysis that studies such functions (more specifically, '''holomorphic''' functions) on the complex plane, or part (domain) or extension (Riemann surface) thereof. It notably has great importance in number theory, e.g. the [[Riemann zeta function]] (for the distribution of primes) and other <math>L</math>-functions, modular forms, elliptic functions, etc. <blockquote>The shortest path between two truths in the real domain passes through the complex domain. — [[wikipedia:Jacques_Hadamard|Jacques Hadamard]]</blockquote>In a certain sense, the essence of complex functions is captured by the principle of [[analytic continuation]].{{mathematics}} ==''' Complex Functions '''== * Complex Functions ([[Media:CAnal.1.A.CFunction.20140222.Basic.pdf|1.A.pdf]], [[Media:CAnal.1.B.CFunction.20140111.Octave.pdf|1.B.pdf]], [[Media:CAnal.1.C.CFunction.20140111.Extend.pdf|1.C.pdf]]) * Complex Exponential and Logarithm ([[Media:CAnal.5.A.CLog.20131017.pdf|5.A.pdf]], [[Media:CAnal.5.A.Octave.pdf|5.B.pdf]]) * Complex Trigonometric and Hyperbolic ([[Media:CAnal.7.A.CTrigHyper..pdf|7.A.pdf]], [[Media:CAnal.7.A.Octave..pdf|7.B.pdf]]) '''Complex Function Note''' : 1. Exp and Log Function Note ([[Media:ComplexExp.29160721.pdf|H1.pdf]]) : 2. Trig and TrigH Function Note ([[Media:CAnal.Trig-H.29160901.pdf|H1.pdf]]) : 3. Inverse Trig and TrigH Functions Note ([[Media:CAnal.Hyper.29160829.pdf|H1.pdf]]) ==''' Complex Integrals '''== * Complex Integrals ([[Media:CAnal.2.A.CIntegral.20140224.Basic.pdf|2.A.pdf]], [[Media:CAnal.2.B.CIntegral.20140117.Octave.pdf|2.B.pdf]], [[Media:CAnal.2.C.CIntegral.20140117.Extend.pdf|2.C.pdf]]) ==''' Complex Series '''== * Complex Series ([[Media:CPX.Series.20150226.2.Basic.pdf|3.A.pdf]], [[Media:CAnal.3.B.CSeries.20140121.Octave.pdf|3.B.pdf]], [[Media:CAnal.3.C.CSeries.20140303.Extend.pdf|3.C.pdf]]) ==''' Residue Integrals '''== * Residue Integrals ([[Media:CAnal.4.A.Residue.20140227.Basic.pdf|4.A.pdf]], [[Media:CAnal.4.B.pdf|4.B.pdf]], [[Media:CAnal.4.C.Residue.20140423.Extend.pdf|4.C.pdf]]) ==='''Residue Integrals Note'''=== * Laurent Series with the Residue Theorem Note ([[Media:Laurent.1.Residue.20170713.pdf|H1.pdf]]) * Laurent Series with Applications Note ([[Media:Laurent.2.Applications.20170327.pdf|H1.pdf]]) * Laurent Series and the z-Transform Note ([[Media:Laurent.3.z-Trans.20170831.pdf|H1.pdf]]) * Laurent Series as a Geometric Series Note ([[Media:Laurent.4.GSeries.20170802.pdf|H1.pdf]]) === Laurent Series and the z-Transform Example Note === * Overview ([[Media:Laurent.4.z-Example.20170926.pdf|H1.pdf]]) ====Geometric Series Examples==== * Causality ([[Media:Laurent.5.Causality.1.A.20191026n.pdf|A.pdf]], [[Media:Laurent.5.Causality.1.B.20191026.pdf|B.pdf]]) * Time Shift ([[Media:Laurent.5.TimeShift.2.A.20191028.pdf|A.pdf]], [[Media:Laurent.5.TimeShift.2.B.20191029.pdf|B.pdf]]) * Reciprocity ([[Media:Laurent.5.Reciprocity.3A.20191030.pdf|A.pdf]], [[Media:Laurent.5.Reciprocity.3B.20191031.pdf|B.pdf]]) * Combinations ([[Media:Laurent.5.Combination.4A.20200702.pdf|A.pdf]], [[Media:Laurent.5.Combination.4B.20201002.pdf|B.pdf]]) * Properties ([[Media:Laurent.5.Property.5A.20220105.pdf|A.pdf]], [[Media:Laurent.5.Property.5B.20220126.pdf|B.pdf]]) * Applications ([[Media:Laurent.6.Application.6A.20220811.pdf|A.pdf]], [[Media:Laurent.5.Application.6B.20220723.pdf|B.pdf]]) * Double Pole Case :- Examples ([[Media:Laurent.5.DPoleEx.7A.20220722.pdf|A.pdf]], [[Media:Laurent.5.DPoleEx.7B.20220720.pdf|B.pdf]]) :- Properties ([[Media:Laurent.5.DPoleProp.5A.20190226.pdf|A.pdf]], [[Media:Laurent.5.DPoleProp.5B.20190228.pdf|B.pdf]]) ====The Case Examples==== * Example Overview : ([[Media:Laurent.4.Example.0.A.20171208.pdf|0A.pdf]], [[Media:Laurent.6.CaseExample.0.B.20180205.pdf|0B.pdf]]) * Example Case 1 : ([[Media:Laurent.4.Example.1.A.20171107.pdf|1A.pdf]], [[Media:Laurent.4.Example.1.B.20171227.pdf|1B.pdf]]) * Example Case 2 : ([[Media:Laurent.4.Example.2.A.20171107.pdf|2A.pdf]], [[Media:Laurent.4.Example.2.B.20171227.pdf|2B.pdf]]) * Example Case 3 : ([[Media:Laurent.4.Example.3.A.20171017.pdf|3A.pdf]], [[Media:Laurent.4.Example.3.B.20171226.pdf|3B.pdf]]) * Example Case 4 : ([[Media:Laurent.4.Example.4.A.20171017.pdf|4A.pdf]], [[Media:Laurent.4.Example.4.B.20171228.pdf|4B.pdf]]) * Example Summary : ([[Media:Laurent.4.Example.5.A.20171212.pdf|5A.pdf]], [[Media:Laurent.4.Example.5.B.20171230.pdf|5B.pdf]]) ==''' Conformal Mapping '''== * Conformal Mapping ([[Media:CAnal.6.A.Conformal.20131224.pdf|6.A.pdf]], [[Media:CAnal.6.A.Octave..pdf|6.B.pdf]]) go to [ [[Electrical_%26_Computer_Engineering_Studies]] ] [[Category:Complex analysis]] ntg3e5shnc9221plpc7y2i8t9gcdvf1 0 171008 2414051 2412382 2022-08-13T08:34:40Z Young1lim 21186 /* The Temporal Characteristics of Random Processes */ wikitext text/x-wiki ==''' Random Variables '''== === Single Random Variables === * Random Variables ([[Media:RV1.RVariable.1.A.20200427.pdf |A.pdf]]) * Distribution Function ([[Media:RV1.Distribution.2.A.201200428.pdf |A.pdf]]) * Density Function ([[Media:RV1.Density.3.A.20200429.pdf |A.pdf]]) * Functions of Random Variables ([[Media:RV1.RVFunction.4.A.20220317.pdf |A.pdf]]) * Gaussian Random Variables ([[Media:RV1.4.Gaussian.20200430.pdf |A.pdf]], [[Media:RV1.4B.Gaussian.20180314.pdf |B.pdf]]) * Other Distribution and Density Functions ([[Media:RV1.5.Other.20200501.pdf |A.pdf]]) * Conditional Distribution and Density Functions ([[Media:RV1.6.Conditional.20200506.pdf |A.pdf]]) </br> === The Characteristics of a Single Random Variable === * Expected Value ([[Media:RV2.Expectation.1.A.20200506.pdf |A.pdf]]) * Moments ([[Media:RV2.Moment.2.B.20200507.pdf |A.pdf]], [[Media:RV2.Moment.2.B.20180320.pdf |B.pdf]]) * Moment Generating Functions ([[Media:RV2.MFunctions.3.A.20200508.pdf |A.pdf]]) * Transformations of Random Variables ([[Media:RV2.Transform.4.A.20200514.pdf |A.pdf]]) </br> === Multiple Random Variables === * Vector Random Variables ([[Media:3MRV.1A.VectorRV.20200515.pdf |A.pdf]]) * Joint Distribution ([[Media:3MRV.2A.JointDist.20200518.pdf |A.pdf]]) * Joint Density ([[Media:3MRV.3A.JointDensity.20200521.pdf |A.pdf]]) * Conditional Joint Distribution and Density ([[Media:3MRV.4A.CondDistrib.20200527.pdf |A.pdf]]) * Statistical Independence ([[Media:3MRV.5A.StatIndep.20200423.pdf |A.pdf]]) * Sums of Random Variables ([[Media:3MRV.6A.RVSum.20200528.pdf |A.pdf]]) * Central Limit Theorem ([[Media:3MRV.7A.CLimit.20200612.pdf |A.pdf]]) </br> === The Characteristics of Multiple Random Variables === * Expected Values ([[Media:4MRV.1A.Expect.20200617.pdf |A.pdf]]) * Joint Characteristic Functions ([[Media:4MRV.2A.JChar.20200618.pdf |A.pdf]]) * Jointly Gaussian Random Variables ([[Media:4MRV.3A.JGauss.20200619.pdf |A.pdf]]) * Transformations of Multiple Random Variables ([[Media:4MRV.4A.Transform.20200620.pdf |A.pdf]]) * Linear Transformation of Gaussian Random Variables ([[Media:4MRV.5A.LinearTrans.20200623.pdf |A.pdf]]) * Simulating Multiple Random Variables ([[Media:4MRV.6A.Simulation.20200624.pdf |A.pdf]]) * Sampling and Some Limit Theorem ([[Media:4MRV.7A.LimitTheorem.20200625.pdf |A.pdf]]) * Complex Random Variables ([[Media:4MRV.8A.ComplexRV.20200626.pdf |A.pdf]]) </br> ==''' Random Processes '''== === The Temporal Characteristics of Random Processes === * Random Processes ([[Media:5MRV.1A.RandomProcess.20210216.pdf |A.pdf]]) * Joint Distribution, Independence, Processes ([[Media:5MRV.2A.JointDistribution.20210220.pdf |A.pdf]]) * Stationary Random Processes ([[Media:5MRV.3A.Stationary.20220402.pdf |A.pdf]], [[Media:5MRV.3B.Stationary.20220808.pdf |B.pdf]]) * Covariance & Correlation of Random Variables ([[Media:5MRV.4A.CovCorrRV.20210910.pdf |A.pdf]]) * Covariance & Correlation of Random Processses ([[Media:5MRV.5A.CovCorrRP.20210911.pdf |A.pdf]]) * Example Random Processes ([[Media:5MRV.4A.Example.20210227.pdf |A.pdf]]) * Ergodic Random Processes ([[Media:5MRV.5A.Ergodicity.20211022.pdf |A.pdf]], [[Media:5MRV.7B.Ergodicity.20211215.pdf |B.pdf]]) * Measurement of Correlation Functions ([[Media:5MRV.6A.Measure.20201013.pdf |A.pdf]]) * Complex Random Processes ([[Media:5MRV.7A.Complex.20201022.pdf |A.pdf]]) </br> === The Spectral Characteristics of Random Processes === * Power Density Spectrum - Continuous Time ([[Media:6MRV.1A.PSpecCT.20210204.pdf |A.pdf]]) * Auto Correlation Function ([[Media:6MRV.2A.AutoCor.20201218.pdf |A.pdf]]) * Power Density Spectrum - Discrete Time ([[Media:6MRV.3A.PSpecDT.20201203.pdf |A.pdf]]) * Cross Power Density Spectrum ([[Media:6MRV.4A.CPSpec.20191108.pdf |A.pdf]]) * Cross Correlation Function ([[Media:6MRV.5A.CCorrel.20191114.pdf |A.pdf]]) * Noise Definitions ([[Media:6MRV.6A.Noise.20191121.pdf |A.pdf]]) * Power Spectrum of Complex Random Processes ([[Media:6MRV.7A.ComplexProc.20191125.pdf |A.pdf]]) </br> === Linear System with Random Inputs === * Continuous Time LTI System ([[Media:7LTI.1A.CTime.20191203.pdf |A.pdf]]) * Discrete Time LTI System ([[Media:7LTI.2A.DTime.20191211.pdf |A.pdf]]) * System Response ([[Media:7LTI.3A.Response.20191224.pdf |A.pdf]]) * Spectral Characteristics ([[Media:7LTI.4A.Spectral.20200104.pdf |A.pdf]]) * Noise Modeling ([[Media:7LTI.5A.Noise.20200122.pdf |A.pdf]]) <br> === Optimum Linear System === * Maximum SNR ([[Media:8OPT.1A.MaxSNR.20200128.pdf |A.pdf]]) * Minimum Squared Error ([[Media:8OPT.2A.MinSE.20200207.pdf |A.pdf]]) <br> === Noise in Some Application Systems === * AM Communication Systems ([[Media:9APP.1A.AM.20200212.pdf |A.pdf]]) * FM Communication Systems ([[Media:9APP.2A.FM.20200221.pdf |A.pdf]]) * Control Systems ([[Media:9APP.3A.Control.20200225.pdf |A.pdf]]) * PLL Systems ([[Media:9APP.4A.PLL.20200305.pdf |A.pdf]]) * Random Waveforms ([[Media:9APP.5A.RandWave.20200311.pdf |A.pdf]]) * Radar Systems ([[Media:9APP.6A.Radar.20200313.pdf |A.pdf]]) <br> ==''' Correlation and Power Spectra '''== # Correlation Functions of Random Signals ([[Media:RAND.1.A.Correlation.20121106.pdf |pdf]]) # Spectra of Random Signals ([[Media:RAND.2.A.Spectra.20121108.pdf |pdf]]) </br> ==''' Ergodicity, Statistics, Estimation '''== </br> ==''' Random Processes and Linear Systems '''== </br> # Time Domain Techniques for Noisy Signals ([[Media:RAND.3.A.Time.20130205.pdf |A.pdf]], [[Media:Dirichlet.pdf |B.pdf]]) # Frequency Domain Techniques for Noisy Signals # Correlation v.s. Convolution for Noisy Signals </br> # System Identification ([[Media:RP.SysId.1.A.pdf |pdf]]) # Matched Filter <ref>[[Understanding Digital Communications]], See Baseband Mod/Demod Section</ref> </br> </br> go to [ [[Electrical_%26_Computer_Engineering_Studies]] ] 1rta2rj7yae068zxzjspg2v0hto1ly6 2414053 2414051 2022-08-13T08:36:24Z Young1lim 21186 /* The Temporal Characteristics of Random Processes */ wikitext text/x-wiki ==''' Random Variables '''== === Single Random Variables === * Random Variables ([[Media:RV1.RVariable.1.A.20200427.pdf |A.pdf]]) * Distribution Function ([[Media:RV1.Distribution.2.A.201200428.pdf |A.pdf]]) * Density Function ([[Media:RV1.Density.3.A.20200429.pdf |A.pdf]]) * Functions of Random Variables ([[Media:RV1.RVFunction.4.A.20220317.pdf |A.pdf]]) * Gaussian Random Variables ([[Media:RV1.4.Gaussian.20200430.pdf |A.pdf]], [[Media:RV1.4B.Gaussian.20180314.pdf |B.pdf]]) * Other Distribution and Density Functions ([[Media:RV1.5.Other.20200501.pdf |A.pdf]]) * Conditional Distribution and Density Functions ([[Media:RV1.6.Conditional.20200506.pdf |A.pdf]]) </br> === The Characteristics of a Single Random Variable === * Expected Value ([[Media:RV2.Expectation.1.A.20200506.pdf |A.pdf]]) * Moments ([[Media:RV2.Moment.2.B.20200507.pdf |A.pdf]], [[Media:RV2.Moment.2.B.20180320.pdf |B.pdf]]) * Moment Generating Functions ([[Media:RV2.MFunctions.3.A.20200508.pdf |A.pdf]]) * Transformations of Random Variables ([[Media:RV2.Transform.4.A.20200514.pdf |A.pdf]]) </br> === Multiple Random Variables === * Vector Random Variables ([[Media:3MRV.1A.VectorRV.20200515.pdf |A.pdf]]) * Joint Distribution ([[Media:3MRV.2A.JointDist.20200518.pdf |A.pdf]]) * Joint Density ([[Media:3MRV.3A.JointDensity.20200521.pdf |A.pdf]]) * Conditional Joint Distribution and Density ([[Media:3MRV.4A.CondDistrib.20200527.pdf |A.pdf]]) * Statistical Independence ([[Media:3MRV.5A.StatIndep.20200423.pdf |A.pdf]]) * Sums of Random Variables ([[Media:3MRV.6A.RVSum.20200528.pdf |A.pdf]]) * Central Limit Theorem ([[Media:3MRV.7A.CLimit.20200612.pdf |A.pdf]]) </br> === The Characteristics of Multiple Random Variables === * Expected Values ([[Media:4MRV.1A.Expect.20200617.pdf |A.pdf]]) * Joint Characteristic Functions ([[Media:4MRV.2A.JChar.20200618.pdf |A.pdf]]) * Jointly Gaussian Random Variables ([[Media:4MRV.3A.JGauss.20200619.pdf |A.pdf]]) * Transformations of Multiple Random Variables ([[Media:4MRV.4A.Transform.20200620.pdf |A.pdf]]) * Linear Transformation of Gaussian Random Variables ([[Media:4MRV.5A.LinearTrans.20200623.pdf |A.pdf]]) * Simulating Multiple Random Variables ([[Media:4MRV.6A.Simulation.20200624.pdf |A.pdf]]) * Sampling and Some Limit Theorem ([[Media:4MRV.7A.LimitTheorem.20200625.pdf |A.pdf]]) * Complex Random Variables ([[Media:4MRV.8A.ComplexRV.20200626.pdf |A.pdf]]) </br> ==''' Random Processes '''== === The Temporal Characteristics of Random Processes === * Random Processes ([[Media:5MRV.1A.RandomProcess.20210216.pdf |A.pdf]]) * Joint Distribution, Independence, Processes ([[Media:5MRV.2A.JointDistribution.20210220.pdf |A.pdf]]) * Stationary Random Processes ([[Media:5MRV.3A.Stationary.20220402.pdf |A.pdf]], [[Media:5MRV.3B.Stationary.20220809.pdf |B.pdf]]) * Covariance & Correlation of Random Variables ([[Media:5MRV.4A.CovCorrRV.20210910.pdf |A.pdf]]) * Covariance & Correlation of Random Processses ([[Media:5MRV.5A.CovCorrRP.20210911.pdf |A.pdf]]) * Example Random Processes ([[Media:5MRV.4A.Example.20210227.pdf |A.pdf]]) * Ergodic Random Processes ([[Media:5MRV.5A.Ergodicity.20211022.pdf |A.pdf]], [[Media:5MRV.7B.Ergodicity.20211215.pdf |B.pdf]]) * Measurement of Correlation Functions ([[Media:5MRV.6A.Measure.20201013.pdf |A.pdf]]) * Complex Random Processes ([[Media:5MRV.7A.Complex.20201022.pdf |A.pdf]]) </br> === The Spectral Characteristics of Random Processes === * Power Density Spectrum - Continuous Time ([[Media:6MRV.1A.PSpecCT.20210204.pdf |A.pdf]]) * Auto Correlation Function ([[Media:6MRV.2A.AutoCor.20201218.pdf |A.pdf]]) * Power Density Spectrum - Discrete Time ([[Media:6MRV.3A.PSpecDT.20201203.pdf |A.pdf]]) * Cross Power Density Spectrum ([[Media:6MRV.4A.CPSpec.20191108.pdf |A.pdf]]) * Cross Correlation Function ([[Media:6MRV.5A.CCorrel.20191114.pdf |A.pdf]]) * Noise Definitions ([[Media:6MRV.6A.Noise.20191121.pdf |A.pdf]]) * Power Spectrum of Complex Random Processes ([[Media:6MRV.7A.ComplexProc.20191125.pdf |A.pdf]]) </br> === Linear System with Random Inputs === * Continuous Time LTI System ([[Media:7LTI.1A.CTime.20191203.pdf |A.pdf]]) * Discrete Time LTI System ([[Media:7LTI.2A.DTime.20191211.pdf |A.pdf]]) * System Response ([[Media:7LTI.3A.Response.20191224.pdf |A.pdf]]) * Spectral Characteristics ([[Media:7LTI.4A.Spectral.20200104.pdf |A.pdf]]) * Noise Modeling ([[Media:7LTI.5A.Noise.20200122.pdf |A.pdf]]) <br> === Optimum Linear System === * Maximum SNR ([[Media:8OPT.1A.MaxSNR.20200128.pdf |A.pdf]]) * Minimum Squared Error ([[Media:8OPT.2A.MinSE.20200207.pdf |A.pdf]]) <br> === Noise in Some Application Systems === * AM Communication Systems ([[Media:9APP.1A.AM.20200212.pdf |A.pdf]]) * FM Communication Systems ([[Media:9APP.2A.FM.20200221.pdf |A.pdf]]) * Control Systems ([[Media:9APP.3A.Control.20200225.pdf |A.pdf]]) * PLL Systems ([[Media:9APP.4A.PLL.20200305.pdf |A.pdf]]) * Random Waveforms ([[Media:9APP.5A.RandWave.20200311.pdf |A.pdf]]) * Radar Systems ([[Media:9APP.6A.Radar.20200313.pdf |A.pdf]]) <br> ==''' Correlation and Power Spectra '''== # Correlation Functions of Random Signals ([[Media:RAND.1.A.Correlation.20121106.pdf |pdf]]) # Spectra of Random Signals ([[Media:RAND.2.A.Spectra.20121108.pdf |pdf]]) </br> ==''' Ergodicity, Statistics, Estimation '''== </br> ==''' Random Processes and Linear Systems '''== </br> # Time Domain Techniques for Noisy Signals ([[Media:RAND.3.A.Time.20130205.pdf |A.pdf]], [[Media:Dirichlet.pdf |B.pdf]]) # Frequency Domain Techniques for Noisy Signals # Correlation v.s. Convolution for Noisy Signals </br> # System Identification ([[Media:RP.SysId.1.A.pdf |pdf]]) # Matched Filter <ref>[[Understanding Digital Communications]], See Baseband Mod/Demod Section</ref> </br> </br> go to [ [[Electrical_%26_Computer_Engineering_Studies]] ] 1yipbkcy7rwyrh7n29jmebam0kneycj 0 203942 2414057 2413254 2022-08-13T08:53:52Z Young1lim 21186 /* Monads III : Mutable State Monads */ wikitext text/x-wiki ==Introduction== * Overview I ([[Media:HSKL.Overview.1.A.20160806.pdf |pdf]]) * Overview II ([[Media:HSKL.Overview.2.A.20160926.pdf |pdf]]) * Overview III ([[Media:HSKL.Overview.3.A.20161011.pdf |pdf]]) * Overview IV ([[Media:HSKL.Overview.4.A.20161104.pdf |pdf]]) * Overview V ([[Media:HSKL.Overview.5.A.20161108.pdf |pdf]]) </br> ==Applications== * Sudoku Background ([[Media:Sudoku.Background.0.A.20161108.pdf |pdf]]) * Bird's Implementation :- Specification ([[Media:Sudoku.1Bird.1.A.Spec.20170425.pdf |pdf]]) :- Rules ([[Media:Sudoku.1Bird.2.A.Rule.20170201.pdf |pdf]]) :- Pruning ([[Media:Sudoku.1Bird.3.A.Pruning.20170211.pdf |pdf]]) :- Expanding ([[Media:Sudoku.1Bird.4.A.Expand.20170506.pdf |pdf]]) </br> ==Using GHCi== * Getting started ([[Media:GHCi.Start.1.A.20170605.pdf |pdf]]) </br> ==Using Libraries== * Library ([[Media:Library.1.A.20170605.pdf |pdf]]) </br> </br> ==Function Oriented Typeclasses== === Background === * Constructors ([[Media:Background.1.A.Constructor.20180904.pdf |pdf]]) * TypeClasses ([[Media:Background.1.B.TypeClass.20180904.pdf |pdf]]) * Functions ([[Media:Background.1.C.Function.20180712.pdf |pdf]]) * Expressions ([[Media:Background.1.D.Expression.20180707.pdf |pdf]]) * Operators ([[Media:Background.1.E.Operator.20180707.pdf |pdf]]) === Functors === * Functor Overview ([[Media:Functor.1.A.Overview.20180802.pdf |pdf]]) * Function Functor ([[Media:Functor.2.A.Function.20180804.pdf |pdf]]) * Functor Lifting ([[Media:Functor.2.B.Lifting.20180721.pdf |pdf]]) === Applicatives === * Applicatives Overview ([[Media:Applicative.3.A.Overview.20180606.pdf |pdf]]) * Applicatives Methods ([[Media:Applicative.3.B.Method.20180519.pdf |pdf]]) * Function Applicative ([[Media:Applicative.3.A.Function.20180804.pdf |pdf]]) * Applicatives Sequencing ([[Media:Applicative.3.C.Sequencing.20180606.pdf |pdf]]) === Monads I : Background === * Side Effects ([[Media:Monad.P1.1A.SideEffect.20190316.pdf |pdf]]) * Monad Overview ([[Media:Monad.P1.2A.Overview.20190308.pdf |pdf]]) * Monadic Operations ([[Media:Monad.P1.3A.Operations.20190308.pdf |pdf]]) * Maybe Monad ([[Media:Monad.P1.4A.Maybe.201900606.pdf |pdf]]) * IO Actions ([[Media:Monad.P1.5A.IOAction.20190606.pdf |pdf]]) * Several Monad Types ([[Media:Monad.P1.6A.Types.20191016.pdf |pdf]]) === Monads II : State Transformer Monads === * State Transformer : - State Transformer Basics ([[Media:MP2.1A.STrans.Basic.20191002.pdf |pdf]]) : - State Transformer Generic Monad ([[Media:MP2.1B.STrans.Generic.20191002.pdf |pdf]]) : - State Transformer Monads ([[Media:MP2.1C.STrans.Monad.20191022.pdf |pdf]]) * State Monad : - State Monad Basics ([[Media:MP2.2A.State.Basic.20190706.pdf |pdf]]) : - State Monad Methods ([[Media:MP2.2B.State.Method.20190706.pdf |pdf]]) : - State Monad Examples ([[Media:MP2.2C.State.Example.20190706.pdf |pdf]]) === Monads III : Mutable State Monads === * Mutability Background : - Types ([[Media:MP3.1A.Mut.Type.20200721.pdf |pdf]]) : - Primitive Types ([[Media:MP3.1B.Mut.PrimType.20200611.pdf |pdf]]) : - Polymorphic Types ([[Media:MP3.1C.Mut.Polymorphic.20201212.pdf |pdf]]) : - Continuation Passing Style ([[Media:MP3.1D.Mut.Continuation.20220110.pdf |pdf]]) : - Expressions ([[Media:MP3.1E.Mut.Expression.20220628.pdf |pdf]]) : - Lambda Calculus ([[Media:MP3.1F.Mut.LambdaCal.20220810.pdf |pdf]]) : - Non-terminating Expressions ([[Media:MP3.1F.Mut.Non-terminating.20220616.pdf |pdf]]) : - Inhabitedness ([[Media:MP3.1F.Mut.Inhabited.20220319.pdf |pdf]]) : - Existential Types ([[Media:MP3.1E.Mut.Existential.20220128.pdf |pdf]]) : - forall Keyword ([[Media:MP3.1E.Mut.forall.20210316.pdf |pdf]]) : - Mutability and Strictness ([[Media:MP3.1C.Mut.Strictness.20200613.pdf |pdf]]) : - Strict and Lazy Packages ([[Media:MP3.1D.Mut.Package.20200620.pdf |pdf]]) * Mutable Objects : - Mutable Variables ([[Media:MP3.1B.Mut.Variable.20200224.pdf |pdf]]) : - Mutable Data Structures ([[Media:MP3.1D.Mut.DataStruct.20191226.pdf |pdf]]) * IO Monad : - IO Monad Basics ([[Media:MP3.2A.IO.Basic.20191019.pdf |pdf]]) : - IO Monad Methods ([[Media:MP3.2B.IO.Method.20191022.pdf |pdf]]) : - IORef Mutable Variable ([[Media:MP3.2C.IO.IORef.20191019.pdf |pdf]]) * ST Monad : - ST Monad Basics ([[Media:MP3.3A.ST.Basic.20191031.pdf |pdf]]) : - ST Monad Methods ([[Media:MP3.3B.ST.Method.20191023.pdf |pdf]]) : - STRef Mutable Variable ([[Media:MP3.3C.ST.STRef.20191023.pdf |pdf]]) === Monads IV : Reader and Writer Monads === * Function Monad ([[Media:Monad.10.A.Function.20180806.pdf |pdf]]) * Monad Transformer ([[Media:Monad.3.I.Transformer.20180727.pdf |pdf]]) * MonadState Class :: - State & StateT Monads ([[Media:Monad.9.A.MonadState.Monad.20180920.pdf |pdf]]) :: - MonadReader Class ([[Media:Monad.9.B.MonadState.Class.20180920.pdf |pdf]]) * MonadReader Class :: - Reader & ReaderT Monads ([[Media:Monad.11.A.Reader.20180821.pdf |pdf]]) :: - MonadReader Class ([[Media:Monad.12.A.MonadReader.20180821.pdf |pdf]]) * Control Monad ([[Media:Monad.9.A.Control.20180908.pdf |pdf]]) === Monoid === * Monoids ([[Media:Monoid.4.A.20180508.pdf |pdf]]) === Arrow === * Arrows ([[Media:Arrow.1.A.20190504.pdf |pdf]]) </br> ==Polymorphism== * Polymorphism Overview ([[Media:Poly.1.A.20180220.pdf |pdf]]) </br> ==Concurrent Haskell == </br> go to [ [[Electrical_%26_Computer_Engineering_Studies]] ] ==External links== * [http://learnyouahaskell.com/introduction Learn you Haskell] * [http://book.realworldhaskell.org/read/ Real World Haskell] * [http://www.scs.stanford.edu/14sp-cs240h/slides/ Standford Class Material] [[Category:Computer programming]] c44m3uppwyix8w5jhd8t0r03w62vado 2414059 2414057 2022-08-13T08:55:40Z Young1lim 21186 /* Monads III : Mutable State Monads */ wikitext text/x-wiki ==Introduction== * Overview I ([[Media:HSKL.Overview.1.A.20160806.pdf |pdf]]) * Overview II ([[Media:HSKL.Overview.2.A.20160926.pdf |pdf]]) * Overview III ([[Media:HSKL.Overview.3.A.20161011.pdf |pdf]]) * Overview IV ([[Media:HSKL.Overview.4.A.20161104.pdf |pdf]]) * Overview V ([[Media:HSKL.Overview.5.A.20161108.pdf |pdf]]) </br> ==Applications== * Sudoku Background ([[Media:Sudoku.Background.0.A.20161108.pdf |pdf]]) * Bird's Implementation :- Specification ([[Media:Sudoku.1Bird.1.A.Spec.20170425.pdf |pdf]]) :- Rules ([[Media:Sudoku.1Bird.2.A.Rule.20170201.pdf |pdf]]) :- Pruning ([[Media:Sudoku.1Bird.3.A.Pruning.20170211.pdf |pdf]]) :- Expanding ([[Media:Sudoku.1Bird.4.A.Expand.20170506.pdf |pdf]]) </br> ==Using GHCi== * Getting started ([[Media:GHCi.Start.1.A.20170605.pdf |pdf]]) </br> ==Using Libraries== * Library ([[Media:Library.1.A.20170605.pdf |pdf]]) </br> </br> ==Function Oriented Typeclasses== === Background === * Constructors ([[Media:Background.1.A.Constructor.20180904.pdf |pdf]]) * TypeClasses ([[Media:Background.1.B.TypeClass.20180904.pdf |pdf]]) * Functions ([[Media:Background.1.C.Function.20180712.pdf |pdf]]) * Expressions ([[Media:Background.1.D.Expression.20180707.pdf |pdf]]) * Operators ([[Media:Background.1.E.Operator.20180707.pdf |pdf]]) === Functors === * Functor Overview ([[Media:Functor.1.A.Overview.20180802.pdf |pdf]]) * Function Functor ([[Media:Functor.2.A.Function.20180804.pdf |pdf]]) * Functor Lifting ([[Media:Functor.2.B.Lifting.20180721.pdf |pdf]]) === Applicatives === * Applicatives Overview ([[Media:Applicative.3.A.Overview.20180606.pdf |pdf]]) * Applicatives Methods ([[Media:Applicative.3.B.Method.20180519.pdf |pdf]]) * Function Applicative ([[Media:Applicative.3.A.Function.20180804.pdf |pdf]]) * Applicatives Sequencing ([[Media:Applicative.3.C.Sequencing.20180606.pdf |pdf]]) === Monads I : Background === * Side Effects ([[Media:Monad.P1.1A.SideEffect.20190316.pdf |pdf]]) * Monad Overview ([[Media:Monad.P1.2A.Overview.20190308.pdf |pdf]]) * Monadic Operations ([[Media:Monad.P1.3A.Operations.20190308.pdf |pdf]]) * Maybe Monad ([[Media:Monad.P1.4A.Maybe.201900606.pdf |pdf]]) * IO Actions ([[Media:Monad.P1.5A.IOAction.20190606.pdf |pdf]]) * Several Monad Types ([[Media:Monad.P1.6A.Types.20191016.pdf |pdf]]) === Monads II : State Transformer Monads === * State Transformer : - State Transformer Basics ([[Media:MP2.1A.STrans.Basic.20191002.pdf |pdf]]) : - State Transformer Generic Monad ([[Media:MP2.1B.STrans.Generic.20191002.pdf |pdf]]) : - State Transformer Monads ([[Media:MP2.1C.STrans.Monad.20191022.pdf |pdf]]) * State Monad : - State Monad Basics ([[Media:MP2.2A.State.Basic.20190706.pdf |pdf]]) : - State Monad Methods ([[Media:MP2.2B.State.Method.20190706.pdf |pdf]]) : - State Monad Examples ([[Media:MP2.2C.State.Example.20190706.pdf |pdf]]) === Monads III : Mutable State Monads === * Mutability Background : - Types ([[Media:MP3.1A.Mut.Type.20200721.pdf |pdf]]) : - Primitive Types ([[Media:MP3.1B.Mut.PrimType.20200611.pdf |pdf]]) : - Polymorphic Types ([[Media:MP3.1C.Mut.Polymorphic.20201212.pdf |pdf]]) : - Continuation Passing Style ([[Media:MP3.1D.Mut.Continuation.20220110.pdf |pdf]]) : - Expressions ([[Media:MP3.1E.Mut.Expression.20220628.pdf |pdf]]) : - Lambda Calculus ([[Media:MP3.1F.Mut.LambdaCal.20220811.pdf |pdf]]) : - Non-terminating Expressions ([[Media:MP3.1F.Mut.Non-terminating.20220616.pdf |pdf]]) : - Inhabitedness ([[Media:MP3.1F.Mut.Inhabited.20220319.pdf |pdf]]) : - Existential Types ([[Media:MP3.1E.Mut.Existential.20220128.pdf |pdf]]) : - forall Keyword ([[Media:MP3.1E.Mut.forall.20210316.pdf |pdf]]) : - Mutability and Strictness ([[Media:MP3.1C.Mut.Strictness.20200613.pdf |pdf]]) : - Strict and Lazy Packages ([[Media:MP3.1D.Mut.Package.20200620.pdf |pdf]]) * Mutable Objects : - Mutable Variables ([[Media:MP3.1B.Mut.Variable.20200224.pdf |pdf]]) : - Mutable Data Structures ([[Media:MP3.1D.Mut.DataStruct.20191226.pdf |pdf]]) * IO Monad : - IO Monad Basics ([[Media:MP3.2A.IO.Basic.20191019.pdf |pdf]]) : - IO Monad Methods ([[Media:MP3.2B.IO.Method.20191022.pdf |pdf]]) : - IORef Mutable Variable ([[Media:MP3.2C.IO.IORef.20191019.pdf |pdf]]) * ST Monad : - ST Monad Basics ([[Media:MP3.3A.ST.Basic.20191031.pdf |pdf]]) : - ST Monad Methods ([[Media:MP3.3B.ST.Method.20191023.pdf |pdf]]) : - STRef Mutable Variable ([[Media:MP3.3C.ST.STRef.20191023.pdf |pdf]]) === Monads IV : Reader and Writer Monads === * Function Monad ([[Media:Monad.10.A.Function.20180806.pdf |pdf]]) * Monad Transformer ([[Media:Monad.3.I.Transformer.20180727.pdf |pdf]]) * MonadState Class :: - State & StateT Monads ([[Media:Monad.9.A.MonadState.Monad.20180920.pdf |pdf]]) :: - MonadReader Class ([[Media:Monad.9.B.MonadState.Class.20180920.pdf |pdf]]) * MonadReader Class :: - Reader & ReaderT Monads ([[Media:Monad.11.A.Reader.20180821.pdf |pdf]]) :: - MonadReader Class ([[Media:Monad.12.A.MonadReader.20180821.pdf |pdf]]) * Control Monad ([[Media:Monad.9.A.Control.20180908.pdf |pdf]]) === Monoid === * Monoids ([[Media:Monoid.4.A.20180508.pdf |pdf]]) === Arrow === * Arrows ([[Media:Arrow.1.A.20190504.pdf |pdf]]) </br> ==Polymorphism== * Polymorphism Overview ([[Media:Poly.1.A.20180220.pdf |pdf]]) </br> ==Concurrent Haskell == </br> go to [ [[Electrical_%26_Computer_Engineering_Studies]] ] ==External links== * [http://learnyouahaskell.com/introduction Learn you Haskell] * [http://book.realworldhaskell.org/read/ Real World Haskell] * [http://www.scs.stanford.edu/14sp-cs240h/slides/ Standford Class Material] [[Category:Computer programming]] 4aasoyo6n0mwi7tdrjcbi56nlrak5mw 0 207094 2413982 2413398 2022-08-12T15:41:16Z Aherman012 2943941 /* Prediction phase */ wikitext text/x-wiki <noinclude>{{Helping Give Away Psychological Science Banner}}</noinclude> {{medical disclaimer}} {{:{{BASEPAGENAME}}/Sidebar}} ==[[Evidence based assessment/Portfolio template/What is a "portfolio"|'''What is a "portfolio"?''']]== For background information on what assessment portfolios are, click the link in the heading above. Want even 'more' information about this topic? There's an extended version of this page [[Evidence-based assessment/Anorexia nervosa (assessment portfolio)/extended version|here]]. == [[Evidence based assessment/Preparation phase|'''Preparation phase''']] == === Diagnostic criteria for anorexia nervosa === {{blockquotetop}} '''ICD-11 Criteria''' Anorexia Nervosa is characterized by significantly low body weight, which is less than minimal normal/expected weight for the individual’s height, sex, age and developmental stage (body mass index (BMI) less than 18.5 kg/m2 in adults and BMI-for-age under fifth percentile in children and adolescents) that is not due to another health condition or to the unavailability of food. Low body weight is accompanied by a persistent pattern of behaviors to prevent restoration of normal weight, which may include behaviors aimed at reducing energy intake (restricted eating), purging behaviors (e.g., self-induced vomiting, misuse of laxatives), and behaviors aimed at increasing energy expenditure (e.g., excessive exercise), typically associated with a fear of weight gain. Low body weight or shape is central to the person's self-evaluation or is inaccurately perceived to be normal or even excessive. '''Changes in DSM-5''' * The diagnostic criteria for anorexia nervosa changed slightly from [[DSM-IV]] to [[w:Diagnostic_and_Statistical_Manual_of_Mental_Disorders#DSM-IV-TR_.282000.29|DSM-5]]. Summaries are available [http://www.dsm5.org/Documents/changes%20from%20dsm-iv-tr%20to%20dsm-5.pdf here] and [[w:DSM-5|here]]. {{blockquotebottom}} === Base rates of anorexia nervosa in different populations and clinical settings === This section describes the demographic setting of the population(s) sampled, base rates of diagnosis such as prevalence rates, country/region sampled, and the diagnostic method that was used. Using this information, clinicians will be able to anchor the rate of adolescent depression that they are likely to see in their clinical practice. * '''''To see prevalence rates across multiple disorders,''''' [[Evidence based assessment/Preparation phase#Base rates for transdiagnostic comparison|'''''click here.''''']] {| class="wikitable sortable" |- ! Demography ! Setting (Reference) ! Base Rate ! Diagnostic Method |- |Nationally representative US sample of adults |Non-clinical: Population-based (NCS-R)<ref>Hudson, James I.; Hiripi, Eva; Pope, Harrison G.; Kessler, Ronald C. (2007-02-01). "The prevalence and correlates of eating disorders in the National Comorbidity Survey Replication".''Biological Psychiatry'' '''61''' (3): 348–358. doi:10.1016/j.biopsych.2006.03.040. ISSN 0006-3223. PMC 1892232. <nowiki>PMID 16815322</nowiki></ref> |.9% Female, .3% Male |World Health Organization-Clinical International Diagnostic Interview (WHO-CIDI) |- |Nationally representative US sample of adolescents |Non-clinical: Population-based (NCS-A)<ref>Swanson, Sonja A.; Crow, Scott J.; Le Grange, Daniel; Swendsen, Joel; Merikangas, Kathleen R. (2011-07-01). "Prevalence and correlates of eating disorders in adolescents. Results from the national comorbidity survey replication adolescent supplement". ''Archives of General Psychiatry'' '''68''' (7): 714–723. doi:10.1001/archgenpsychiatry.2011.22. ISSN 1538-3636.<nowiki>PMID 21383252</nowiki></ref> |.3% Female, .3% Male |WHO-CIDI |- |Nationally representative US sample of 9- and 10-year old children |Non-clinical: US Population-based prevalence (Adolescent Brain Cognitive Development (ABCD) study<ref>{{Cite journal|last=Rozzell|first=Kaitlin|last2=Moon|first2=Da Yeoun|last3=Klimek|first3=Patrycja|last4=Brown|first4=Tiffany|last5=Blashill|first5=Aaron J.|date=2019-01-01|title=Prevalence of Eating Disorders Among US Children Aged 9 to 10 Years: Data From the Adolescent Brain Cognitive Development (ABCD) Study|url=http://archpedi.jamanetwork.com/article.aspx?doi=10.1001/jamapediatrics.2018.3678|journal=JAMA Pediatrics|language=en|volume=173|issue=1|pages=100|doi=10.1001/jamapediatrics.2018.3678|issn=2168-6203|pmc=PMC6583451|pmid=30476983}}</ref> |0.1%, no gender differences |DSM-5 using Kiddie Schedule for Affective Disorders and Schizophrenia (KSADS) |- |Latino Households in the US |Non-clinical: Latinos in US<ref>Alegria, Margarita; Woo, Meghan; Cao, Zhun; Torres, Maria; Meng, Xiao-li; Striegel-Moore, Ruth (2007-11-01). "Prevalence and correlates of eating disorders in Latinos in the United States".''The International Journal of Eating Disorders''. 40 Suppl: S15–21. doi:10.1002/eat.20406. ISSN 0276-3478. PMC 2680162. <nowiki>PMID 17584870</nowiki></ref> |.12% Female, .03% Male |WHO-CIDI |- |National probability sample of adult and adolescent African Americans and Caribbean Blacks |Non-clinical: African Americans and Caribbean Blacks in the US (NSAL)<ref>Taylor, Jacquelyn Y.; Caldwell, Cleopatra Howard; Baser, Raymond E.; Faison, Nakesha; Jackson, James S. (2007-11-01). "Prevalence of eating disorders among Blacks in the National Survey of American Life". ''The International Journal of Eating Disorders''. 40 Suppl: S10–14. doi:10.1002/eat.20451. ISSN 0276-3478. PMC 2882704. <nowiki>PMID 17879287</nowiki></ref> |.14% Female, .2% Male |WHO-CIDI |- |Asian American adults in US households |Non-clinical: National Latino and Asian American Study (NLAAS) |.12% Female, .05% Male |WHO-CIDI |- | US African American college females | Non-clinical; college students<ref>Tyler ID. A true picture of eating disorders among African American women: a review of literature. ABNF J. 2003;14(3):73-4.</ref> || .0% || Eating Disorder Diagnostic Questionnaire (EDD-Q) |- | US Female Adolescents | Non-clinical; Adolescents<ref>Stice, E., Becker, C. B., & Yokum, S. (2013). Eating disorder prevention: Current evidence-base and future directions. ''Int. J. Eat. Disord. International Journal of Eating Disorders,'' ''46''(5), 478-485.</ref> || .8% || Eating Disorder Diagnosis Interview (EDDI) |- | US Division-I Varsity Student Athletes | Non-clinical; student-athletes<ref>Johnson C, Powers PS, Dick R. Athletes and eating disorders: the national collegiate athletic association study. Int J Eat Disord 1999;26:179e88.</ref> || .0% || Eating Disorder Inventory-2 (EDI-2) |- | Active duty females in US Army, Navy, Airforce, and Marines | Non-clinical; Military<ref>McNulty, PAF. (2001). Prevalence and contributing factors of eating disorder behaviors in active duty service women in the Army, Navy, Air Force and Marines. Military Medicine, 166(1), 53-58. </ref> || 1.1% || EDI-2 |- |US Caucasian female same-sex twins |Non-clinical; Commonwealth of Virginia Mid-Atlantic Twin Registry (MATR)<ref>Kendler KS, Walters EE, Neale MC, Kessler R, Heath A, Eaves L. The structure of genetic and environmental risk factors for six major psychiatric disorders in women. Archives of general psychiatry. 1995;52:374–383.</ref> |1.62% (narrow), 3.70% (broad) |Structured Clinical Interview for DSM Disorders (SCID) |- |South Australian older adolescents and adults |Non-clinical; Health Omnibus Survey (HOS) |.46% (3 months; combined) |Eating Disorder Examination (EDE) |- |US Military |Military<ref>{{Cite journal|title=Diagnosed eating disorders in the U.S. Military: a nine year review|url=http://www.ncbi.nlm.nih.gov/pubmed/18821361|journal=Eating Disorders|date=2008-12-01|issn=1532-530X|pmid=18821361|pages=363–377|volume=16|issue=5|doi=10.1080/10640260802370523|first=Amanda J.|last=Antczak|first2=Teresa L.|last2=Brininger}}</ref> |.04% (combined) |ICD codes from electronic records |- |US Military Academy cadets |Non-clinical; Military |.02% (7 years) Female, 0.0% (7 years) Males |[https://www.eat-26.com/ Eating Attitudes Test- 26 items] (EAT-26)<ref>{{Cite web|url=https://www.eat-26.com/|title=EAT-26: Eating Attitudes Test & Eating Disorder Testing – Use the EAT-26 to help you determine if you need to speak to a mental health professional to get help for an eating disorder.|last=admin|language=en|access-date=2022-05-30}}</ref> |- |US Navy female nurses |Non-clinical; Military |1.1% (current & past) Female |DSM-III |- |US veterans |Non-clinical; Military |.04% Female, .005% Males |ICD-9-CM |- |Active duty males in US Navy |Non-clinical; Military |2.5% Males |N/A |- |US alcohol-dependent adults from San Diego, St. Lois, Iowa City, Farmington, New York, & Indianapolis |Clinical; Collaborative Study on the Genetics of Alcoholism (COGA)<ref>{{Cite journal|title=Anorexia nervosa and bulimia nervosa in alcohol-dependent men and women and their relatives|url=http://www.ncbi.nlm.nih.gov/pubmed/8540597|journal=The American Journal of Psychiatry|date=1996-01-01|issn=0002-953X|pmid=8540597|pages=74–82|volume=153|issue=1|doi=10.1176/ajp.153.1.74|first=M. A.|last=Schuckit|first2=J. E.|last2=Tipp|first3=R. M.|last3=Anthenelli|first4=K. K.|last4=Bucholz|first5=V. M.|last5=Hesselbrock|first6=J. I.|last6=Nurnberger}}</ref> |1.41% (lifetime) Female, .00% (lifetime) Male |SSAGA |- |Healthcare provider records |Non-clinical; healthcare members |.0269% (current) | |- |US high school students in west central Oregon |Non-clinical; high school students |. 00% (point), .45% (lifetime) Female .00% (point), .00% (lifetime) Males |DSM-III-R₄ |- |Canadian treatment-seeking substance users |Clinical; substance users |.4% (lifetime), .3% (current) Female .4% (lifetime), .3% (current) Males |DIS₉ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''Europe''' |- |Adolescent females residing in Navarra, Spain |Non-clinical; adolescents |.3% Female |EAT-40₃ |- |Adolescents in secondary schools in Sør-Trøndelag, County in Norway |Non-clinical; adolescents |.7% (lifetime) Female, .2% Male |SEDs₁₀ |- |Adolescents in a comprehensive school in Ostrobothnia district in Finland |Non-clinical; adolescents |.7% (point; age 15), 1.8% (lifetime, age 15), .00% (point, age 18), 2.6% (lifetime, age 18), .9% (3 years) Female .00% (point & lifetime) Males |RAB-T₁₁&nbsp;& RAB-R₁₂ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''Australia''' |- |Adolescent females residing in Victoria, Australia |Non-clinical; adolescents |.00% (full), 1.8% (partial) Female |BET₁₃ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''Central & South America''' |- |Mexican first & second year college females |Non-clinical; college students |.00% Female |EAT-40₃ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''East Asia''' |- |Adolescent and adult Japanese patients at a university hospital |Clinical; eating disorder patients |.53% Female |DSM-III-R₄ |- |Korean adults |Non-clinical; Korean Epidemiologic Catchment Area (KECA) Study |.1% (lifetime), .1% (12 months) Female .2% (lifetime), .00% (12 months) Males |K-CIDI₁₅&nbsp;2.1 |- |Alcohol-dependent adults |Centers participating in the Collaborative Study on the Genetics of Alcoholism in San Diego; St. Louis; Iowa City; Farmington, CN; New York; & Indianapolis |1.41% Females |Semi-Structured Assessment for the Genetics of Alcoholism; criteria based on DSM-III-R |} ==[[Evidence based assessment/Prediction phase|'''Prediction phase''']]== === Psychometric properties of screening instruments for anorexia nervosa === The following section contains a list of screening and diagnostic instruments for anorexia nerova. The section includes administration information, psychometric data, and PDFs or links to the screenings. * Screenings are used as part of the [[Evidence based assessment/Prediction phase|prediction phase]] of assessment; for more information on interpretation of this data, or how screenings fit in to the assessment process, click [[Evidence based assessment/Prediction phase|here.]] * ''For a list of more broadly reaching screening instruments, [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prediction_phase&wteswitched=1#Psychometric_properties_of_common_screening_instruments '''click here.''']'' {| class="wikitable" |- ! Measure !Format (Reporter) !Age Range !Administration/ Completion Time !Where to Access |- |[[wikipedia:Eating_Disorder_Examination_Interview|Eating Disorder Examination Questionnaire (EDE-Q)]] |Questionnaire (Patient) |14+ |15-20 min | - [http://www.corc.uk.net/media/1273/ede-q_quesionnaire.pdf PDF] |- |[[wikipedia:Eating_Disorder_Diagnostic_Scale|EDDS (Eating Disorder Diagnosis Scale)]]<ref>{{Cite journal|last=Stice|first=Eric|last2=Telch|first2=Christy F.|last3=Rizvi|first3=Shireen L.|date=2000|title=Development and validation of the Eating Disorder Diagnostic Scale: A brief self-report measure of anorexia, bulimia, and binge-eating disorder.|url=http://doi.apa.org/getdoi.cfm?doi=10.1037/1040-3590.12.2.123|journal=Psychological Assessment|language=en|volume=12|issue=2|pages=123–131|doi=10.1037/1040-3590.12.2.123|issn=1939-134X}}</ref> |Questionnaire (Patient) |13 - 65 |10-15 min | - [http://www.ori.org/files/Static%20Page%20Files/EDDSDSM-5_10_14.pdf PDF] |- |Eating Attitudes Test- 26(EAT-26; Adult version)<ref>{{Cite journal|last=Garner|first=David M.|last2=Garfinkel|first2=Paul E.|date=1979-05|title=The Eating Attitudes Test: an index of the symptoms of anorexia nervosa|url=http://dx.doi.org/10.1017/s0033291700030762|journal=Psychological Medicine|volume=9|issue=2|pages=273–279|doi=10.1017/s0033291700030762|issn=0033-2917}}</ref> Child Eating Attitudes Test - 26 (ChEAT-26; child version)<ref>{{Cite journal|last=Almeida|first=M.C.|last2=Carvalho|first2=D.L.D.B.|last3=Rigolino|first3=R.|date=2012-07|title=Reliability of a Brazilian version of children's eating attitude test|url=http://dx.doi.org/10.1016/j.neurenf.2012.04.196|journal=Neuropsychiatrie de l'Enfance et de l'Adolescence|volume=60|issue=5|pages=S158|doi=10.1016/j.neurenf.2012.04.196|issn=0222-9617}}</ref> |Questionnaire (Patient) |13+ (adult version) 8 -13 (child version) |5-10 min |[https://www.eat-26.com/eat-26/ - Adult Version PDF]- [http://www.1000livesplus.wales.nhs.uk/sitesplus/documents/1011/ChEAT.pdf Child Version PDF] |} <ref>Hunsley, J., & Mash, E. J. (2008). Guide to Assessments that Work. Cary, NC, USA: Oxford University Press, USA. Retrieved from <nowiki>http://www.ebrary.com</nowiki></ref>'''Note:''' '''L''' = Less than adequate; '''A''' = Adequate; '''G''' = Good; '''E''' = Excellent; '''U''' = Unavailable; '''NA''' = Not applicable ===Likelihood ratios and AUCs of screening instruments for anorexia nervosa=== * ''For a list of the likelihood ratios for more broadly reaching screening instruments, [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prediction_phase&wteswitched=1#Likelihood_ratios_and_AUCs_of_common_screening_instruments '''click here.''']'' {| class="wikitable sortable" border="1" |- ! <ref name=":4">{{Cite journal|last=Mintz|first=L. B.|last2=O'Halloran|first2=M. S.|date=June 2000|title=The Eating Attitudes Test: validation with DSM-IV eating disorder criteria|url=https://www.ncbi.nlm.nih.gov/pubmed/10900574|journal=Journal of Personality Assessment|volume=74|issue=3|pages=489–503|doi=10.1207/S15327752JPA7403_11|issn=0022-3891|pmid=10900574}}</ref>Screening Measure (Primary Reference) ! AUC ! DiLR+ (Score) ! DiLR- (Score) !Clinical Generalizability !Where to access |- |Serum leptin level<ref name=":7">{{Cite journal|last=Föcker|first=M.|last2=Timmesfeld|first2=N.|last3=Scherag|first3=S.|last4=Bühren|first4=K.|last5=Langkamp|first5=M.|last6=Dempfle|first6=A.|last7=Sheridan|first7=E. M.|last8=Zwaan|first8=M. de|last9=Fleischhaker|first9=C.|date=2011-04-01|title=Screening for anorexia nervosa via measurement of serum leptin levels|url=https://link.springer.com/article/10.1007/s00702-010-0551-z|journal=Journal of Neural Transmission|language=en|volume=118|issue=4|pages=571–578|doi=10.1007/s00702-010-0551-z|issn=0300-9564}}</ref> |0.984 (N=139) |14.72 (<2.31) |0.10 (2.31+) |Adolescent and adult patients in the acute phase of AN according to the DSM-IV and no AN pretreatment versus healthy lean female volunteer university students. |None |- |Body Mass Index (BMI)<ref name=":7" /> |0.936 (N=139) |5.89 (<17.10) |0.11 (17.10+) |Adolescent and adult patients in the acute phase of AN according to the DSM-IV and no AN pretreatment versus healthy lean female volunteer university students. |None |- |EAT-26&nbsp;<ref name=":4" /><ref>{{Cite journal|title = The eating attitudes test: psychometric features and clinical correlates|url = http://www.ncbi.nlm.nih.gov/pubmed/6961471|journal = Psychological Medicine|date = 1982-11-01|issn = 0033-2917|pmid = 6961471|pages = 871–878|volume = 12|issue = 4|first = D. M.|last = Garner|first2 = M. P.|last2 = Olmsted|first3 = Y.|last3 = Bohr|first4 = P. E.|last4 = Garfinkel}}</ref> |.90 (N=129) |12.83 (20+) |.24 (<20) |Low-moderate: College women with no eating disorder versus college women with a DSM-IV eating disorder. Eating disorders were not separated. |[https://www.eat-26.com/eat-26/ Adult Version PDF][http://www.1000livesplus.wales.nhs.uk/sitesplus/documents/1011/ChEAT.pdf Child Version PDF] |- |EDE-Q&nbsp;<ref name=":1">{{Cite journal|title = Assessment of eating disorders: interview or self-report questionnaire?|url = http://www.ncbi.nlm.nih.gov/pubmed/7866415|journal = The International Journal of Eating Disorders|date = 1994-12-01|issn = 0276-3478|pmid = 7866415|pages = 363–370|volume = 16|issue = 4|first = C. G.|last = Fairburn|first2 = S. J.|last2 = Beglin}}</ref> |.96 &nbsp;<ref name=":1" />(N=1170) | 6.57 (2.3+)<ref name=":5">{{Cite journal|last=Fairburn|first=C. G.|last2=Beglin|first2=S. J.|date=December 1994|title=Assessment of eating disorders: interview or self-report questionnaire?|url=https://www.ncbi.nlm.nih.gov/pubmed/7866415|journal=The International Journal of Eating Disorders|volume=16|issue=4|pages=363–370|issn=0276-3478|pmid=7866415}}</ref> | 0.09 (<2.3)<ref name=":5" /> |Moderate: Dutch treatment-seeking females meeting DSM-IV criteria for an eating disorder versus female adult general population sample recruited through advertisements and personal contacts. Eating disorders were not separated.&nbsp;<ref name=":1" /> Moderate: “Clinically significant eating disorder” from a community sample versus female adults individuals without “clinically significant eating disorder” from same sample. Eating disorders were not separated.<ref name=":5" /> |[http://www.corc.uk.net/media/1273/ede-q_quesionnaire.pdf PDF] |} === Interpreting anorexia nervosa screening measure scores === * For information on interpreting screening measure scores, click [[Evidence based assessment/Prediction phase#Interpreting screening measure scores|here.]] * Also see the page on [https://en.wikipedia.org/wiki/Likelihood_ratios_in_diagnostic_testing likelihood ratios in diagnostic testing] for more information. ==[[Evidence based assessment/Prescription phase|'''Prescription phase''']]== ===Gold standard diagnostic interviews=== * For a list of broad reaching diagnostic interviews sortable by disorder with PDFs (if applicable), [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prescription_phase&wteswitched=1#Common_Diagnostic_Interviews click here.] ===Recommended diagnostic interviews for anorexia nervosa=== {| class="wikitable sortable" border="1" ! colspan="5" |Diagnostic instruments for anorexia nervosa |- ! Measure ! Format (Reporter) ! Age Range ! Administration/ Completion Time !Where to access |- |[https://www.credo-oxford.com/7.2.html Eating Disorder Examination (EDE)] <ref>{{Cite book|url=https://www.worldcat.org/oclc/1160972551|title=Assessment of disorders in childhood and adolescence|date=2020|others=Eric Arden Youngstrom, Mitchell J. Prinstein, Eric J. Mash, Russell A. Barkley|isbn=978-1-4625-4365-6|edition=Fifth edition|location=New York|oclc=1160972551}}</ref> <ref>{{Cite book|url=https://www.worldcat.org/oclc/314222270|title=A guide to assessments that work|date=2008|publisher=Oxford University Press|others=John Hunsley, Eric J. Mash|isbn=0-19-804245-0|location=New York|oclc=314222270}}</ref> |Semistructured (child and adult) |8-16 (child version) 16+ (adult version) |45-75 minutes |[https://www.phenxtoolkit.org/protocols/view/230101 Child version PDF][https://www.credo-oxford.com/7.2.html Adult version PDF][https://osf.io/eytc5 PDF] |- |Structured Clinical Interview for DSM-5-Clinician Version (SCID-5-CV)<ref>{{Cite journal|last=Shabani|first=Amir|last2=Masoumian|first2=Samira|last3=Zamirinejad|first3=Somayeh|last4=Hejri|first4=Maryam|last5=Pirmorad|first5=Tahereh|last6=Yaghmaeezadeh|first6=Hooman|date=2021-05|title=Psychometric properties of Structured Clinical Interview for DSM‐5 Disorders‐Clinician Version (SCID‐5‐CV)|url=https://onlinelibrary.wiley.com/doi/10.1002/brb3.1894|journal=Brain and Behavior|language=en|volume=11|issue=5|doi=10.1002/brb3.1894|issn=2162-3279|pmc=PMC8119811|pmid=33729681}}</ref> |Structured Interview (Adult ) |16+ |Varies |[https://www.columbiapsychiatry.org/research/research-labs/diagnostic-and-assessment-lab/structured-clinical-interview-dsm-disorders-11 Website to purchase] |- | [https://dawba.info/a0.html Development and Well-Being Assessment (DAWBA)] <ref>{{Cite book|url=https://www.worldcat.org/oclc/1160972551|title=Assessment of disorders in childhood and adolescence|date=2020|others=Eric Arden Youngstrom, Mitchell J. Prinstein, Eric J. Mash, Russell A. Barkley|isbn=978-1-4625-4365-6|edition=Fifth edition|location=New York|oclc=1160972551}}</ref> | Structured (child/adolescent and parent) | 11-18 |10-20 minutes for the eating disorder module |[https://osf.io/zpbna/?view_only=245bef061d284c17ab9dedad5a59e1b8 English PDF] [https://dawba.info/py/dawbainfo/b1.py Additional languages] |} '''Note:''' '''L''' = Less than adequate; '''A''' = Adequate; '''G''' = Good; '''E''' = Excellent; '''U''' = Unavailable; '''NA''' = Not applicable ==[[Evidence based assessment/Process phase|'''Process phase''']]== The following section contains a brief overview of treatment options for anorexia nervosa and a list of process and outcome measures for anorexia nervosa. The section includes benchmarks based on published norms for several outcome and severity measures, as well as information about commonly used process measures. Process and outcome measures are used as part of the [[Evidence based assessment/Process phase|process phase]] of assessment. For more information on the differences between process and outcome measures, see the page on the [[Evidence based assessment/Process phase|process phase of assessment]]. ===Process measures=== Body weight is commonly monitored by clinicians throughout the AN treatment process as helping individuals regain and maintain a healthy weight is a primary treatment goal for AN. Many treatment centers have policies prohibiting patients from seeing their weight. Motivational Stages of Change may be used to monitor individuals’ readiness to take action against eating disorder behaviors. It has demonstrated predictive validity in a sample of female adolescents attending eating disorder treatment groups.<ref>{{Cite journal|last=Gusella|first=Joanne|last2=Butler|first2=Gordon|last3=Nichols|first3=Laura|last4=Bird|first4=Debbie|date=2003-01-01|title=A brief questionnaire to assess readiness to change in adolescents with eating disorders: its applications to group therapy|url=http://onlinelibrary.wiley.com/doi/10.1002/erv.481/abstract|journal=European Eating Disorders Review|language=en|volume=11|issue=1|pages=58–71|doi=10.1002/erv.481|issn=1099-0968}}</ref> See Appendix E. === Outcome and severity measures === This table includes clinically significant benchmarks for anorexia nervosa specific outcome measures * Information on how to interpret this table can be [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Process_phase found here]. * Additionally, these [[Evidence based assessment/Vignettes|vignettes]] might be helpful resources for understanding appropriate adaptation of outcome measures in practice. *''<u>For clinically significant change benchmarks for the CBCL, YSR, and TRF total, externalizing, internalizing, and attention benchmarks,</u>'' [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Process_phase&wteswitched=1#Clinically_significant_change_benchmarks_for_widely-used_outcome_measures see here.] {| class="wikitable sortable" border="1" | colspan="8" |'''Clinically significant change benchmarks with common instruments for anorexia nervosa''' |- | colspan="8" span style="font-size:110%; text-align:center;" | <b> Benchmarks Based on Published Norms</b> |- | rowspan="2" style="text-align:center;font-size:130%;" |<b> Measure</b> | rowspan="2" style="text-align:center;font-size:130%;" | <b> Subscale</b> | colspan="3" style="text-align:center;font-size:130%" width="300" | <b> Cut-off scores</b> | colspan="3" style="text-align:center;font-size:120%" | <b> Critical Change <br> (unstandardized scores)</b> |- | style="text-align:center;font-size:110%" |<b> A</b> | style="text-align:center;font-size:110%" |<b> B</b> | style="text-align:center;font-size:110%" |<b> C</b> | style="text-align:center;font-size:110%" |<b> 95%</b> | style="text-align:center;font-size:110%" |<b> 90%</b> | style="text-align:center;font-size:110%" |<b> SE_difference</b> |- | rowspan="5" style="text-align:center;" |'''EDE-Q <ref name=":2">{{Cite journal|last=Mond|first=J. M.|last2=Hay|first2=P. J.|last3=Rodgers|first3=B.|last4=Owen|first4=C.|last5=Beumont|first5=P. J. V.|date=May 2004|title=Validity of the Eating Disorder Examination Questionnaire (EDE-Q) in screening for eating disorders in community samples|url=https://www.ncbi.nlm.nih.gov/pubmed/15033501|journal=Behaviour Research and Therapy|volume=42|issue=5|pages=551–567|doi=10.1016/S0005-7967(03)00161-X|issn=0005-7967|pmid=15033501}}</ref>''' | style="text-align:right;" |''Global'' |1.4 |3.2 |2.3 |.7 |.6 |.3 |- | style="text-align:right;" |''Restraint'' |(-.3) |3.6 |1.8 |1.5 |1.2 |.8 |- | style="text-align:right;" |''Eating Concern'' |.1 |2.0 |1.2 |1.1 |.9 |.6 |- | style="text-align:right;" |''Weight Concern'' |1.5 |3.9 |2.6 |1.0 |.9 |.5 |- | style="text-align:right;" |''Shape Concern'' |2.1 |4.8 |3.2 |.9 |.7 |.4 |- | rowspan="5" style="text-align:center;" |'''EDE <ref name=":2" />''' | style="text-align:right;" |''Global'' |1.7 |2.3 |1.9 |1.9 |1.6 |1.0 |- | style="text-align:right;" |''Restraint'' |.3 |3.3 |1.9 |1.8 |1.5 |.9 |- | style="text-align:right;" |''Eating Concern'' |(-.5) |.9 |.5 |.8 |.7 |.4 |- | style="text-align:right;" |''Weight Concern'' |2.0 |2.8 |2.4 |1.3 |1.1 |.7 |- | style="text-align:right;" |''Shape Concern'' |2.0 |3.2 |2.6 |1.2 |1.0 |.6 |- | rowspan="1" style="text-align:center;" |'''EAT-26 <ref name=":0">{{Cite journal|last=Mintz|first=L. B.|last2=O'Halloran|first2=M. S.|date=2000-06-01|title=The Eating Attitudes Test: validation with DSM-IV eating disorder criteria|url=http://www.ncbi.nlm.nih.gov/pubmed/10900574|journal=Journal of Personality Assessment|volume=74|issue=3|pages=489–503|doi=10.1207/S15327752JPA7403_11|issn=0022-3891|pmid=10900574}}</ref>''' | style="text-align:right;" |''Total'' |6.5 |19.6 |15.0 |7.9 |6.7 |4.0 |} '''Note:''' “A” = Away from the clinical range, “B” = Back into the nonclinical range, “C” = Closer to the nonclinical than clinical mean. '''Search terms:''' [Anorexia Nervosa OR eating disorder] AND [validity OR clinical significance] in Google Scholar === Treatment === {{collapse top| Click here for more information on treatment for AN}} * Treatment of AN typically consists of restoring the individual to a healthy weight and addressing thoughts and behaviors which are related to the eating disorder. It may involve re-nutrition, psychotherapy, nutritional counseling, and medication. * Literature reviews of existing research indicate that evidence supporting AN treatment is lacking. A systematic review of AN treatment efficacy studies by Bulik<ref>{{Cite journal|title = Anorexia nervosa treatment: a systematic review of randomized controlled trials|url = http://www.ncbi.nlm.nih.gov/pubmed/17370290|journal = The International Journal of Eating Disorders|date = 2007-05-01|issn = 0276-3478|pmid = 17370290|pages = 310–320|volume = 40|issue = 4|doi = 10.1002/eat.20367|first = Cynthia M.|last = Bulik|first2 = Nancy D.|last2 = Berkman|first3 = Kimberly A.|last3 = Brownley|first4 = Jan A.|last4 = Sedway|first5 = Kathleen N.|last5 = Lohr}}</ref> found that evidence supporting medications, medications and behavioral interventions, and behavioral interventions alone in adults is weak. * There is moderately strong evidence suggesting that behavioral interventions may be helpful for adolescents. In particular, adolescents may benefit from family therapy. * Clinical trials investigating AN treatment suffer from high rates of attrition, as key features of AN (e.g., denial, fear of weight gain) may contribute to low motivation for remaining in treatment. * More severe cases of AN may be treated in inpatient settings, which are equipped to manage the re-nutrition process and provide medical monitoring. * Partial hospitalization and intensive outpatient programs may provide intermediate levels of treatment intensity to assist individuals in the transition from intensive care to outpatient care after weight restoration. {{collapse bottom}} * Please refer to the page on [https://en.wikipedia.org/wiki/Anorexia_nervosa anorexia nervosa] for more information on available treatment or go to [http://effectivechildtherapy.org/concerns-symptoms-disorders/disorders/eating-body-image-problems/ the Effective Child Therapy page for Eating & Body Image Problems] for a curated resource on effective treatments for anorexia nervosa. == '''External resources''' == # [http://apps.who.int/classifications/icd10/browse/2010/en#/F50.0 ICD-10 diagnostic criteria] # [https://en.wikiversity.org/w/index.php?title=Helping_Give_Away_Psychological_Science/Resources/Annotated_List_of_Where_and_How_to_Find_a_Therapist&wteswitched=1#Other_low-cost_options Find-a-Therapist] ##This is a curated list of find-a-therapist websites where you can find a provider # NIMH: [https://www.nimh.nih.gov/health/publications/eating-disorders/index.shtml ''Eating Disorders--About More Than Food''] and [https://www.nimh.nih.gov/health/topics/eating-disorders/index.shtml ''Eating Disorders''] ##These NIMH website posts provide more information on anorexia nervosa #[https://www.hopkinsmedicine.org/psychiatry/specialty_areas/eating_disorders/ John's Hopkins Resource] (guide about anorexia nervosa, treatment, and more) # OMIM (Online Mendelian Inheritance in Man) ##[https://www.omim.org/entry/606788?search=anorexia%20nervosa&highlight=nervosa%20anorexia Anorexia nervosa] #[http://effectivechildtherapy.org/concerns-symptoms-disorders/disorders/eating-body-image-problems/ Effective Child Therapy page for anorexia nervosa] ##Effective Child Therapy is website sponsored by Division 53 of the American Psychological Association (APA), or The [https://sccap53.org Society of Clinical Child and Adolescent Psychology] (SCCAP), in collaboration with the Association for Behavioral and Cognitive Therapies (ABCT). Use for information on symptoms and available treatments. == '''References''' == {{collapse top|Click here for references}} {{Reflist|30em}} [[Category:Psychological disorder portfolios|{{SUBPAGENAME}}]] {{collapse bottom}} 24802z6ppwf0wc51ofh58fvdxmnyx61 2413983 2413982 2022-08-12T15:41:56Z Aherman012 2943941 /* Prediction phase */ wikitext text/x-wiki <noinclude>{{Helping Give Away Psychological Science Banner}}</noinclude> {{medical disclaimer}} {{:{{BASEPAGENAME}}/Sidebar}} ==[[Evidence based assessment/Portfolio template/What is a "portfolio"|'''What is a "portfolio"?''']]== For background information on what assessment portfolios are, click the link in the heading above. Want even 'more' information about this topic? There's an extended version of this page [[Evidence-based assessment/Anorexia nervosa (assessment portfolio)/extended version|here]]. == [[Evidence based assessment/Preparation phase|'''Preparation phase''']] == === Diagnostic criteria for anorexia nervosa === {{blockquotetop}} '''ICD-11 Criteria''' Anorexia Nervosa is characterized by significantly low body weight, which is less than minimal normal/expected weight for the individual’s height, sex, age and developmental stage (body mass index (BMI) less than 18.5 kg/m2 in adults and BMI-for-age under fifth percentile in children and adolescents) that is not due to another health condition or to the unavailability of food. Low body weight is accompanied by a persistent pattern of behaviors to prevent restoration of normal weight, which may include behaviors aimed at reducing energy intake (restricted eating), purging behaviors (e.g., self-induced vomiting, misuse of laxatives), and behaviors aimed at increasing energy expenditure (e.g., excessive exercise), typically associated with a fear of weight gain. Low body weight or shape is central to the person's self-evaluation or is inaccurately perceived to be normal or even excessive. '''Changes in DSM-5''' * The diagnostic criteria for anorexia nervosa changed slightly from [[DSM-IV]] to [[w:Diagnostic_and_Statistical_Manual_of_Mental_Disorders#DSM-IV-TR_.282000.29|DSM-5]]. Summaries are available [http://www.dsm5.org/Documents/changes%20from%20dsm-iv-tr%20to%20dsm-5.pdf here] and [[w:DSM-5|here]]. {{blockquotebottom}} === Base rates of anorexia nervosa in different populations and clinical settings === This section describes the demographic setting of the population(s) sampled, base rates of diagnosis such as prevalence rates, country/region sampled, and the diagnostic method that was used. Using this information, clinicians will be able to anchor the rate of adolescent depression that they are likely to see in their clinical practice. * '''''To see prevalence rates across multiple disorders,''''' [[Evidence based assessment/Preparation phase#Base rates for transdiagnostic comparison|'''''click here.''''']] {| class="wikitable sortable" |- ! Demography ! Setting (Reference) ! Base Rate ! Diagnostic Method |- |Nationally representative US sample of adults |Non-clinical: Population-based (NCS-R)<ref>Hudson, James I.; Hiripi, Eva; Pope, Harrison G.; Kessler, Ronald C. (2007-02-01). "The prevalence and correlates of eating disorders in the National Comorbidity Survey Replication".''Biological Psychiatry'' '''61''' (3): 348–358. doi:10.1016/j.biopsych.2006.03.040. ISSN 0006-3223. PMC 1892232. <nowiki>PMID 16815322</nowiki></ref> |.9% Female, .3% Male |World Health Organization-Clinical International Diagnostic Interview (WHO-CIDI) |- |Nationally representative US sample of adolescents |Non-clinical: Population-based (NCS-A)<ref>Swanson, Sonja A.; Crow, Scott J.; Le Grange, Daniel; Swendsen, Joel; Merikangas, Kathleen R. (2011-07-01). "Prevalence and correlates of eating disorders in adolescents. Results from the national comorbidity survey replication adolescent supplement". ''Archives of General Psychiatry'' '''68''' (7): 714–723. doi:10.1001/archgenpsychiatry.2011.22. ISSN 1538-3636.<nowiki>PMID 21383252</nowiki></ref> |.3% Female, .3% Male |WHO-CIDI |- |Nationally representative US sample of 9- and 10-year old children |Non-clinical: US Population-based prevalence (Adolescent Brain Cognitive Development (ABCD) study<ref>{{Cite journal|last=Rozzell|first=Kaitlin|last2=Moon|first2=Da Yeoun|last3=Klimek|first3=Patrycja|last4=Brown|first4=Tiffany|last5=Blashill|first5=Aaron J.|date=2019-01-01|title=Prevalence of Eating Disorders Among US Children Aged 9 to 10 Years: Data From the Adolescent Brain Cognitive Development (ABCD) Study|url=http://archpedi.jamanetwork.com/article.aspx?doi=10.1001/jamapediatrics.2018.3678|journal=JAMA Pediatrics|language=en|volume=173|issue=1|pages=100|doi=10.1001/jamapediatrics.2018.3678|issn=2168-6203|pmc=PMC6583451|pmid=30476983}}</ref> |0.1%, no gender differences |DSM-5 using Kiddie Schedule for Affective Disorders and Schizophrenia (KSADS) |- |Latino Households in the US |Non-clinical: Latinos in US<ref>Alegria, Margarita; Woo, Meghan; Cao, Zhun; Torres, Maria; Meng, Xiao-li; Striegel-Moore, Ruth (2007-11-01). "Prevalence and correlates of eating disorders in Latinos in the United States".''The International Journal of Eating Disorders''. 40 Suppl: S15–21. doi:10.1002/eat.20406. ISSN 0276-3478. PMC 2680162. <nowiki>PMID 17584870</nowiki></ref> |.12% Female, .03% Male |WHO-CIDI |- |National probability sample of adult and adolescent African Americans and Caribbean Blacks |Non-clinical: African Americans and Caribbean Blacks in the US (NSAL)<ref>Taylor, Jacquelyn Y.; Caldwell, Cleopatra Howard; Baser, Raymond E.; Faison, Nakesha; Jackson, James S. (2007-11-01). "Prevalence of eating disorders among Blacks in the National Survey of American Life". ''The International Journal of Eating Disorders''. 40 Suppl: S10–14. doi:10.1002/eat.20451. ISSN 0276-3478. PMC 2882704. <nowiki>PMID 17879287</nowiki></ref> |.14% Female, .2% Male |WHO-CIDI |- |Asian American adults in US households |Non-clinical: National Latino and Asian American Study (NLAAS) |.12% Female, .05% Male |WHO-CIDI |- | US African American college females | Non-clinical; college students<ref>Tyler ID. A true picture of eating disorders among African American women: a review of literature. ABNF J. 2003;14(3):73-4.</ref> || .0% || Eating Disorder Diagnostic Questionnaire (EDD-Q) |- | US Female Adolescents | Non-clinical; Adolescents<ref>Stice, E., Becker, C. B., & Yokum, S. (2013). Eating disorder prevention: Current evidence-base and future directions. ''Int. J. Eat. Disord. International Journal of Eating Disorders,'' ''46''(5), 478-485.</ref> || .8% || Eating Disorder Diagnosis Interview (EDDI) |- | US Division-I Varsity Student Athletes | Non-clinical; student-athletes<ref>Johnson C, Powers PS, Dick R. Athletes and eating disorders: the national collegiate athletic association study. Int J Eat Disord 1999;26:179e88.</ref> || .0% || Eating Disorder Inventory-2 (EDI-2) |- | Active duty females in US Army, Navy, Airforce, and Marines | Non-clinical; Military<ref>McNulty, PAF. (2001). Prevalence and contributing factors of eating disorder behaviors in active duty service women in the Army, Navy, Air Force and Marines. Military Medicine, 166(1), 53-58. </ref> || 1.1% || EDI-2 |- |US Caucasian female same-sex twins |Non-clinical; Commonwealth of Virginia Mid-Atlantic Twin Registry (MATR)<ref>Kendler KS, Walters EE, Neale MC, Kessler R, Heath A, Eaves L. The structure of genetic and environmental risk factors for six major psychiatric disorders in women. Archives of general psychiatry. 1995;52:374–383.</ref> |1.62% (narrow), 3.70% (broad) |Structured Clinical Interview for DSM Disorders (SCID) |- |South Australian older adolescents and adults |Non-clinical; Health Omnibus Survey (HOS) |.46% (3 months; combined) |Eating Disorder Examination (EDE) |- |US Military |Military<ref>{{Cite journal|title=Diagnosed eating disorders in the U.S. Military: a nine year review|url=http://www.ncbi.nlm.nih.gov/pubmed/18821361|journal=Eating Disorders|date=2008-12-01|issn=1532-530X|pmid=18821361|pages=363–377|volume=16|issue=5|doi=10.1080/10640260802370523|first=Amanda J.|last=Antczak|first2=Teresa L.|last2=Brininger}}</ref> |.04% (combined) |ICD codes from electronic records |- |US Military Academy cadets |Non-clinical; Military |.02% (7 years) Female, 0.0% (7 years) Males |[https://www.eat-26.com/ Eating Attitudes Test- 26 items] (EAT-26)<ref>{{Cite web|url=https://www.eat-26.com/|title=EAT-26: Eating Attitudes Test & Eating Disorder Testing – Use the EAT-26 to help you determine if you need to speak to a mental health professional to get help for an eating disorder.|last=admin|language=en|access-date=2022-05-30}}</ref> |- |US Navy female nurses |Non-clinical; Military |1.1% (current & past) Female |DSM-III |- |US veterans |Non-clinical; Military |.04% Female, .005% Males |ICD-9-CM |- |Active duty males in US Navy |Non-clinical; Military |2.5% Males |N/A |- |US alcohol-dependent adults from San Diego, St. Lois, Iowa City, Farmington, New York, & Indianapolis |Clinical; Collaborative Study on the Genetics of Alcoholism (COGA)<ref>{{Cite journal|title=Anorexia nervosa and bulimia nervosa in alcohol-dependent men and women and their relatives|url=http://www.ncbi.nlm.nih.gov/pubmed/8540597|journal=The American Journal of Psychiatry|date=1996-01-01|issn=0002-953X|pmid=8540597|pages=74–82|volume=153|issue=1|doi=10.1176/ajp.153.1.74|first=M. A.|last=Schuckit|first2=J. E.|last2=Tipp|first3=R. M.|last3=Anthenelli|first4=K. K.|last4=Bucholz|first5=V. M.|last5=Hesselbrock|first6=J. I.|last6=Nurnberger}}</ref> |1.41% (lifetime) Female, .00% (lifetime) Male |SSAGA |- |Healthcare provider records |Non-clinical; healthcare members |.0269% (current) | |- |US high school students in west central Oregon |Non-clinical; high school students |. 00% (point), .45% (lifetime) Female .00% (point), .00% (lifetime) Males |DSM-III-R₄ |- |Canadian treatment-seeking substance users |Clinical; substance users |.4% (lifetime), .3% (current) Female .4% (lifetime), .3% (current) Males |DIS₉ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''Europe''' |- |Adolescent females residing in Navarra, Spain |Non-clinical; adolescents |.3% Female |EAT-40₃ |- |Adolescents in secondary schools in Sør-Trøndelag, County in Norway |Non-clinical; adolescents |.7% (lifetime) Female, .2% Male |SEDs₁₀ |- |Adolescents in a comprehensive school in Ostrobothnia district in Finland |Non-clinical; adolescents |.7% (point; age 15), 1.8% (lifetime, age 15), .00% (point, age 18), 2.6% (lifetime, age 18), .9% (3 years) Female .00% (point & lifetime) Males |RAB-T₁₁&nbsp;& RAB-R₁₂ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''Australia''' |- |Adolescent females residing in Victoria, Australia |Non-clinical; adolescents |.00% (full), 1.8% (partial) Female |BET₁₃ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''Central & South America''' |- |Mexican first & second year college females |Non-clinical; college students |.00% Female |EAT-40₃ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''East Asia''' |- |Adolescent and adult Japanese patients at a university hospital |Clinical; eating disorder patients |.53% Female |DSM-III-R₄ |- |Korean adults |Non-clinical; Korean Epidemiologic Catchment Area (KECA) Study |.1% (lifetime), .1% (12 months) Female .2% (lifetime), .00% (12 months) Males |K-CIDI₁₅&nbsp;2.1 |- |Alcohol-dependent adults |Centers participating in the Collaborative Study on the Genetics of Alcoholism in San Diego; St. Louis; Iowa City; Farmington, CN; New York; & Indianapolis |1.41% Females |Semi-Structured Assessment for the Genetics of Alcoholism; criteria based on DSM-III-R |} ==[[Evidence based assessment/Prediction phase|'''Prediction phase''']]== === Psychometric properties of screening instruments for anorexia nervosa === The following section contains a list of screening and diagnostic instruments for anorexia nerova. The section includes administration information, psychometric data, and PDFs or links to the screenings. * Screenings are used as part of the [[Evidence based assessment/Prediction phase|prediction phase]] of assessment; for more information on interpretation of this data, or how screenings fit in to the assessment process, click [[Evidence based assessment/Prediction phase|here.]] * ''For a list of more broadly reaching screening instruments, [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prediction_phase&wteswitched=1#Psychometric_properties_of_common_screening_instruments '''click here.''']'' {| class="wikitable" |- ! Measure !Format (Reporter) !Age Range !Administration/ Completion Time !Where to Access |- |[[wikipedia:Eating_Disorder_Examination_Interview|Eating Disorder Examination Questionnaire (EDE-Q)]] |Questionnaire (Patient) |14+ |15-20 min | [http://www.corc.uk.net/media/1273/ede-q_quesionnaire.pdf PDF] |- |[[wikipedia:Eating_Disorder_Diagnostic_Scale|EDDS (Eating Disorder Diagnosis Scale)]]<ref>{{Cite journal|last=Stice|first=Eric|last2=Telch|first2=Christy F.|last3=Rizvi|first3=Shireen L.|date=2000|title=Development and validation of the Eating Disorder Diagnostic Scale: A brief self-report measure of anorexia, bulimia, and binge-eating disorder.|url=http://doi.apa.org/getdoi.cfm?doi=10.1037/1040-3590.12.2.123|journal=Psychological Assessment|language=en|volume=12|issue=2|pages=123–131|doi=10.1037/1040-3590.12.2.123|issn=1939-134X}}</ref> |Questionnaire (Patient) |13 - 65 |10-15 min | - [http://www.ori.org/files/Static%20Page%20Files/EDDSDSM-5_10_14.pdf PDF] |- |Eating Attitudes Test- 26(EAT-26; Adult version)<ref>{{Cite journal|last=Garner|first=David M.|last2=Garfinkel|first2=Paul E.|date=1979-05|title=The Eating Attitudes Test: an index of the symptoms of anorexia nervosa|url=http://dx.doi.org/10.1017/s0033291700030762|journal=Psychological Medicine|volume=9|issue=2|pages=273–279|doi=10.1017/s0033291700030762|issn=0033-2917}}</ref> Child Eating Attitudes Test - 26 (ChEAT-26; child version)<ref>{{Cite journal|last=Almeida|first=M.C.|last2=Carvalho|first2=D.L.D.B.|last3=Rigolino|first3=R.|date=2012-07|title=Reliability of a Brazilian version of children's eating attitude test|url=http://dx.doi.org/10.1016/j.neurenf.2012.04.196|journal=Neuropsychiatrie de l'Enfance et de l'Adolescence|volume=60|issue=5|pages=S158|doi=10.1016/j.neurenf.2012.04.196|issn=0222-9617}}</ref> |Questionnaire (Patient) |13+ (adult version) 8 -13 (child version) |5-10 min |PDFs * [https://www.eat-26.com/eat-26/ Adult Version PDF] * [http://www.1000livesplus.wales.nhs.uk/sitesplus/documents/1011/ChEAT.pdf Child Version PDF] |} <ref>Hunsley, J., & Mash, E. J. (2008). Guide to Assessments that Work. Cary, NC, USA: Oxford University Press, USA. Retrieved from <nowiki>http://www.ebrary.com</nowiki></ref>'''Note:''' '''L''' = Less than adequate; '''A''' = Adequate; '''G''' = Good; '''E''' = Excellent; '''U''' = Unavailable; '''NA''' = Not applicable ===Likelihood ratios and AUCs of screening instruments for anorexia nervosa=== * ''For a list of the likelihood ratios for more broadly reaching screening instruments, [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prediction_phase&wteswitched=1#Likelihood_ratios_and_AUCs_of_common_screening_instruments '''click here.''']'' {| class="wikitable sortable" border="1" |- ! <ref name=":4">{{Cite journal|last=Mintz|first=L. B.|last2=O'Halloran|first2=M. S.|date=June 2000|title=The Eating Attitudes Test: validation with DSM-IV eating disorder criteria|url=https://www.ncbi.nlm.nih.gov/pubmed/10900574|journal=Journal of Personality Assessment|volume=74|issue=3|pages=489–503|doi=10.1207/S15327752JPA7403_11|issn=0022-3891|pmid=10900574}}</ref>Screening Measure (Primary Reference) ! AUC ! DiLR+ (Score) ! DiLR- (Score) !Clinical Generalizability !Where to access |- |Serum leptin level<ref name=":7">{{Cite journal|last=Föcker|first=M.|last2=Timmesfeld|first2=N.|last3=Scherag|first3=S.|last4=Bühren|first4=K.|last5=Langkamp|first5=M.|last6=Dempfle|first6=A.|last7=Sheridan|first7=E. M.|last8=Zwaan|first8=M. de|last9=Fleischhaker|first9=C.|date=2011-04-01|title=Screening for anorexia nervosa via measurement of serum leptin levels|url=https://link.springer.com/article/10.1007/s00702-010-0551-z|journal=Journal of Neural Transmission|language=en|volume=118|issue=4|pages=571–578|doi=10.1007/s00702-010-0551-z|issn=0300-9564}}</ref> |0.984 (N=139) |14.72 (<2.31) |0.10 (2.31+) |Adolescent and adult patients in the acute phase of AN according to the DSM-IV and no AN pretreatment versus healthy lean female volunteer university students. |None |- |Body Mass Index (BMI)<ref name=":7" /> |0.936 (N=139) |5.89 (<17.10) |0.11 (17.10+) |Adolescent and adult patients in the acute phase of AN according to the DSM-IV and no AN pretreatment versus healthy lean female volunteer university students. |None |- |EAT-26&nbsp;<ref name=":4" /><ref>{{Cite journal|title = The eating attitudes test: psychometric features and clinical correlates|url = http://www.ncbi.nlm.nih.gov/pubmed/6961471|journal = Psychological Medicine|date = 1982-11-01|issn = 0033-2917|pmid = 6961471|pages = 871–878|volume = 12|issue = 4|first = D. M.|last = Garner|first2 = M. P.|last2 = Olmsted|first3 = Y.|last3 = Bohr|first4 = P. E.|last4 = Garfinkel}}</ref> |.90 (N=129) |12.83 (20+) |.24 (<20) |Low-moderate: College women with no eating disorder versus college women with a DSM-IV eating disorder. Eating disorders were not separated. |[https://www.eat-26.com/eat-26/ Adult Version PDF][http://www.1000livesplus.wales.nhs.uk/sitesplus/documents/1011/ChEAT.pdf Child Version PDF] |- |EDE-Q&nbsp;<ref name=":1">{{Cite journal|title = Assessment of eating disorders: interview or self-report questionnaire?|url = http://www.ncbi.nlm.nih.gov/pubmed/7866415|journal = The International Journal of Eating Disorders|date = 1994-12-01|issn = 0276-3478|pmid = 7866415|pages = 363–370|volume = 16|issue = 4|first = C. G.|last = Fairburn|first2 = S. J.|last2 = Beglin}}</ref> |.96 &nbsp;<ref name=":1" />(N=1170) | 6.57 (2.3+)<ref name=":5">{{Cite journal|last=Fairburn|first=C. G.|last2=Beglin|first2=S. J.|date=December 1994|title=Assessment of eating disorders: interview or self-report questionnaire?|url=https://www.ncbi.nlm.nih.gov/pubmed/7866415|journal=The International Journal of Eating Disorders|volume=16|issue=4|pages=363–370|issn=0276-3478|pmid=7866415}}</ref> | 0.09 (<2.3)<ref name=":5" /> |Moderate: Dutch treatment-seeking females meeting DSM-IV criteria for an eating disorder versus female adult general population sample recruited through advertisements and personal contacts. Eating disorders were not separated.&nbsp;<ref name=":1" /> Moderate: “Clinically significant eating disorder” from a community sample versus female adults individuals without “clinically significant eating disorder” from same sample. Eating disorders were not separated.<ref name=":5" /> |[http://www.corc.uk.net/media/1273/ede-q_quesionnaire.pdf PDF] |} === Interpreting anorexia nervosa screening measure scores === * For information on interpreting screening measure scores, click [[Evidence based assessment/Prediction phase#Interpreting screening measure scores|here.]] * Also see the page on [https://en.wikipedia.org/wiki/Likelihood_ratios_in_diagnostic_testing likelihood ratios in diagnostic testing] for more information. ==[[Evidence based assessment/Prescription phase|'''Prescription phase''']]== ===Gold standard diagnostic interviews=== * For a list of broad reaching diagnostic interviews sortable by disorder with PDFs (if applicable), [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prescription_phase&wteswitched=1#Common_Diagnostic_Interviews click here.] ===Recommended diagnostic interviews for anorexia nervosa=== {| class="wikitable sortable" border="1" ! colspan="5" |Diagnostic instruments for anorexia nervosa |- ! Measure ! Format (Reporter) ! Age Range ! Administration/ Completion Time !Where to access |- |[https://www.credo-oxford.com/7.2.html Eating Disorder Examination (EDE)] <ref>{{Cite book|url=https://www.worldcat.org/oclc/1160972551|title=Assessment of disorders in childhood and adolescence|date=2020|others=Eric Arden Youngstrom, Mitchell J. Prinstein, Eric J. Mash, Russell A. Barkley|isbn=978-1-4625-4365-6|edition=Fifth edition|location=New York|oclc=1160972551}}</ref> <ref>{{Cite book|url=https://www.worldcat.org/oclc/314222270|title=A guide to assessments that work|date=2008|publisher=Oxford University Press|others=John Hunsley, Eric J. Mash|isbn=0-19-804245-0|location=New York|oclc=314222270}}</ref> |Semistructured (child and adult) |8-16 (child version) 16+ (adult version) |45-75 minutes |[https://www.phenxtoolkit.org/protocols/view/230101 Child version PDF][https://www.credo-oxford.com/7.2.html Adult version PDF][https://osf.io/eytc5 PDF] |- |Structured Clinical Interview for DSM-5-Clinician Version (SCID-5-CV)<ref>{{Cite journal|last=Shabani|first=Amir|last2=Masoumian|first2=Samira|last3=Zamirinejad|first3=Somayeh|last4=Hejri|first4=Maryam|last5=Pirmorad|first5=Tahereh|last6=Yaghmaeezadeh|first6=Hooman|date=2021-05|title=Psychometric properties of Structured Clinical Interview for DSM‐5 Disorders‐Clinician Version (SCID‐5‐CV)|url=https://onlinelibrary.wiley.com/doi/10.1002/brb3.1894|journal=Brain and Behavior|language=en|volume=11|issue=5|doi=10.1002/brb3.1894|issn=2162-3279|pmc=PMC8119811|pmid=33729681}}</ref> |Structured Interview (Adult ) |16+ |Varies |[https://www.columbiapsychiatry.org/research/research-labs/diagnostic-and-assessment-lab/structured-clinical-interview-dsm-disorders-11 Website to purchase] |- | [https://dawba.info/a0.html Development and Well-Being Assessment (DAWBA)] <ref>{{Cite book|url=https://www.worldcat.org/oclc/1160972551|title=Assessment of disorders in childhood and adolescence|date=2020|others=Eric Arden Youngstrom, Mitchell J. Prinstein, Eric J. Mash, Russell A. Barkley|isbn=978-1-4625-4365-6|edition=Fifth edition|location=New York|oclc=1160972551}}</ref> | Structured (child/adolescent and parent) | 11-18 |10-20 minutes for the eating disorder module |[https://osf.io/zpbna/?view_only=245bef061d284c17ab9dedad5a59e1b8 English PDF] [https://dawba.info/py/dawbainfo/b1.py Additional languages] |} '''Note:''' '''L''' = Less than adequate; '''A''' = Adequate; '''G''' = Good; '''E''' = Excellent; '''U''' = Unavailable; '''NA''' = Not applicable ==[[Evidence based assessment/Process phase|'''Process phase''']]== The following section contains a brief overview of treatment options for anorexia nervosa and a list of process and outcome measures for anorexia nervosa. The section includes benchmarks based on published norms for several outcome and severity measures, as well as information about commonly used process measures. Process and outcome measures are used as part of the [[Evidence based assessment/Process phase|process phase]] of assessment. For more information on the differences between process and outcome measures, see the page on the [[Evidence based assessment/Process phase|process phase of assessment]]. ===Process measures=== Body weight is commonly monitored by clinicians throughout the AN treatment process as helping individuals regain and maintain a healthy weight is a primary treatment goal for AN. Many treatment centers have policies prohibiting patients from seeing their weight. Motivational Stages of Change may be used to monitor individuals’ readiness to take action against eating disorder behaviors. It has demonstrated predictive validity in a sample of female adolescents attending eating disorder treatment groups.<ref>{{Cite journal|last=Gusella|first=Joanne|last2=Butler|first2=Gordon|last3=Nichols|first3=Laura|last4=Bird|first4=Debbie|date=2003-01-01|title=A brief questionnaire to assess readiness to change in adolescents with eating disorders: its applications to group therapy|url=http://onlinelibrary.wiley.com/doi/10.1002/erv.481/abstract|journal=European Eating Disorders Review|language=en|volume=11|issue=1|pages=58–71|doi=10.1002/erv.481|issn=1099-0968}}</ref> See Appendix E. === Outcome and severity measures === This table includes clinically significant benchmarks for anorexia nervosa specific outcome measures * Information on how to interpret this table can be [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Process_phase found here]. * Additionally, these [[Evidence based assessment/Vignettes|vignettes]] might be helpful resources for understanding appropriate adaptation of outcome measures in practice. *''<u>For clinically significant change benchmarks for the CBCL, YSR, and TRF total, externalizing, internalizing, and attention benchmarks,</u>'' [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Process_phase&wteswitched=1#Clinically_significant_change_benchmarks_for_widely-used_outcome_measures see here.] {| class="wikitable sortable" border="1" | colspan="8" |'''Clinically significant change benchmarks with common instruments for anorexia nervosa''' |- | colspan="8" span style="font-size:110%; text-align:center;" | <b> Benchmarks Based on Published Norms</b> |- | rowspan="2" style="text-align:center;font-size:130%;" |<b> Measure</b> | rowspan="2" style="text-align:center;font-size:130%;" | <b> Subscale</b> | colspan="3" style="text-align:center;font-size:130%" width="300" | <b> Cut-off scores</b> | colspan="3" style="text-align:center;font-size:120%" | <b> Critical Change <br> (unstandardized scores)</b> |- | style="text-align:center;font-size:110%" |<b> A</b> | style="text-align:center;font-size:110%" |<b> B</b> | style="text-align:center;font-size:110%" |<b> C</b> | style="text-align:center;font-size:110%" |<b> 95%</b> | style="text-align:center;font-size:110%" |<b> 90%</b> | style="text-align:center;font-size:110%" |<b> SE_difference</b> |- | rowspan="5" style="text-align:center;" |'''EDE-Q <ref name=":2">{{Cite journal|last=Mond|first=J. M.|last2=Hay|first2=P. J.|last3=Rodgers|first3=B.|last4=Owen|first4=C.|last5=Beumont|first5=P. J. V.|date=May 2004|title=Validity of the Eating Disorder Examination Questionnaire (EDE-Q) in screening for eating disorders in community samples|url=https://www.ncbi.nlm.nih.gov/pubmed/15033501|journal=Behaviour Research and Therapy|volume=42|issue=5|pages=551–567|doi=10.1016/S0005-7967(03)00161-X|issn=0005-7967|pmid=15033501}}</ref>''' | style="text-align:right;" |''Global'' |1.4 |3.2 |2.3 |.7 |.6 |.3 |- | style="text-align:right;" |''Restraint'' |(-.3) |3.6 |1.8 |1.5 |1.2 |.8 |- | style="text-align:right;" |''Eating Concern'' |.1 |2.0 |1.2 |1.1 |.9 |.6 |- | style="text-align:right;" |''Weight Concern'' |1.5 |3.9 |2.6 |1.0 |.9 |.5 |- | style="text-align:right;" |''Shape Concern'' |2.1 |4.8 |3.2 |.9 |.7 |.4 |- | rowspan="5" style="text-align:center;" |'''EDE <ref name=":2" />''' | style="text-align:right;" |''Global'' |1.7 |2.3 |1.9 |1.9 |1.6 |1.0 |- | style="text-align:right;" |''Restraint'' |.3 |3.3 |1.9 |1.8 |1.5 |.9 |- | style="text-align:right;" |''Eating Concern'' |(-.5) |.9 |.5 |.8 |.7 |.4 |- | style="text-align:right;" |''Weight Concern'' |2.0 |2.8 |2.4 |1.3 |1.1 |.7 |- | style="text-align:right;" |''Shape Concern'' |2.0 |3.2 |2.6 |1.2 |1.0 |.6 |- | rowspan="1" style="text-align:center;" |'''EAT-26 <ref name=":0">{{Cite journal|last=Mintz|first=L. B.|last2=O'Halloran|first2=M. S.|date=2000-06-01|title=The Eating Attitudes Test: validation with DSM-IV eating disorder criteria|url=http://www.ncbi.nlm.nih.gov/pubmed/10900574|journal=Journal of Personality Assessment|volume=74|issue=3|pages=489–503|doi=10.1207/S15327752JPA7403_11|issn=0022-3891|pmid=10900574}}</ref>''' | style="text-align:right;" |''Total'' |6.5 |19.6 |15.0 |7.9 |6.7 |4.0 |} '''Note:''' “A” = Away from the clinical range, “B” = Back into the nonclinical range, “C” = Closer to the nonclinical than clinical mean. '''Search terms:''' [Anorexia Nervosa OR eating disorder] AND [validity OR clinical significance] in Google Scholar === Treatment === {{collapse top| Click here for more information on treatment for AN}} * Treatment of AN typically consists of restoring the individual to a healthy weight and addressing thoughts and behaviors which are related to the eating disorder. It may involve re-nutrition, psychotherapy, nutritional counseling, and medication. * Literature reviews of existing research indicate that evidence supporting AN treatment is lacking. A systematic review of AN treatment efficacy studies by Bulik<ref>{{Cite journal|title = Anorexia nervosa treatment: a systematic review of randomized controlled trials|url = http://www.ncbi.nlm.nih.gov/pubmed/17370290|journal = The International Journal of Eating Disorders|date = 2007-05-01|issn = 0276-3478|pmid = 17370290|pages = 310–320|volume = 40|issue = 4|doi = 10.1002/eat.20367|first = Cynthia M.|last = Bulik|first2 = Nancy D.|last2 = Berkman|first3 = Kimberly A.|last3 = Brownley|first4 = Jan A.|last4 = Sedway|first5 = Kathleen N.|last5 = Lohr}}</ref> found that evidence supporting medications, medications and behavioral interventions, and behavioral interventions alone in adults is weak. * There is moderately strong evidence suggesting that behavioral interventions may be helpful for adolescents. In particular, adolescents may benefit from family therapy. * Clinical trials investigating AN treatment suffer from high rates of attrition, as key features of AN (e.g., denial, fear of weight gain) may contribute to low motivation for remaining in treatment. * More severe cases of AN may be treated in inpatient settings, which are equipped to manage the re-nutrition process and provide medical monitoring. * Partial hospitalization and intensive outpatient programs may provide intermediate levels of treatment intensity to assist individuals in the transition from intensive care to outpatient care after weight restoration. {{collapse bottom}} * Please refer to the page on [https://en.wikipedia.org/wiki/Anorexia_nervosa anorexia nervosa] for more information on available treatment or go to [http://effectivechildtherapy.org/concerns-symptoms-disorders/disorders/eating-body-image-problems/ the Effective Child Therapy page for Eating & Body Image Problems] for a curated resource on effective treatments for anorexia nervosa. == '''External resources''' == # [http://apps.who.int/classifications/icd10/browse/2010/en#/F50.0 ICD-10 diagnostic criteria] # [https://en.wikiversity.org/w/index.php?title=Helping_Give_Away_Psychological_Science/Resources/Annotated_List_of_Where_and_How_to_Find_a_Therapist&wteswitched=1#Other_low-cost_options Find-a-Therapist] ##This is a curated list of find-a-therapist websites where you can find a provider # NIMH: [https://www.nimh.nih.gov/health/publications/eating-disorders/index.shtml ''Eating Disorders--About More Than Food''] and [https://www.nimh.nih.gov/health/topics/eating-disorders/index.shtml ''Eating Disorders''] ##These NIMH website posts provide more information on anorexia nervosa #[https://www.hopkinsmedicine.org/psychiatry/specialty_areas/eating_disorders/ John's Hopkins Resource] (guide about anorexia nervosa, treatment, and more) # OMIM (Online Mendelian Inheritance in Man) ##[https://www.omim.org/entry/606788?search=anorexia%20nervosa&highlight=nervosa%20anorexia Anorexia nervosa] #[http://effectivechildtherapy.org/concerns-symptoms-disorders/disorders/eating-body-image-problems/ Effective Child Therapy page for anorexia nervosa] ##Effective Child Therapy is website sponsored by Division 53 of the American Psychological Association (APA), or The [https://sccap53.org Society of Clinical Child and Adolescent Psychology] (SCCAP), in collaboration with the Association for Behavioral and Cognitive Therapies (ABCT). Use for information on symptoms and available treatments. == '''References''' == {{collapse top|Click here for references}} {{Reflist|30em}} [[Category:Psychological disorder portfolios|{{SUBPAGENAME}}]] {{collapse bottom}} 0zk2rqjt6lwimutq6wyfht0948ocr5m 2413984 2413983 2022-08-12T15:42:12Z Aherman012 2943941 /* Psychometric properties of screening instruments for anorexia nervosa */ wikitext text/x-wiki <noinclude>{{Helping Give Away Psychological Science Banner}}</noinclude> {{medical disclaimer}} {{:{{BASEPAGENAME}}/Sidebar}} ==[[Evidence based assessment/Portfolio template/What is a "portfolio"|'''What is a "portfolio"?''']]== For background information on what assessment portfolios are, click the link in the heading above. Want even 'more' information about this topic? There's an extended version of this page [[Evidence-based assessment/Anorexia nervosa (assessment portfolio)/extended version|here]]. == [[Evidence based assessment/Preparation phase|'''Preparation phase''']] == === Diagnostic criteria for anorexia nervosa === {{blockquotetop}} '''ICD-11 Criteria''' Anorexia Nervosa is characterized by significantly low body weight, which is less than minimal normal/expected weight for the individual’s height, sex, age and developmental stage (body mass index (BMI) less than 18.5 kg/m2 in adults and BMI-for-age under fifth percentile in children and adolescents) that is not due to another health condition or to the unavailability of food. Low body weight is accompanied by a persistent pattern of behaviors to prevent restoration of normal weight, which may include behaviors aimed at reducing energy intake (restricted eating), purging behaviors (e.g., self-induced vomiting, misuse of laxatives), and behaviors aimed at increasing energy expenditure (e.g., excessive exercise), typically associated with a fear of weight gain. Low body weight or shape is central to the person's self-evaluation or is inaccurately perceived to be normal or even excessive. '''Changes in DSM-5''' * The diagnostic criteria for anorexia nervosa changed slightly from [[DSM-IV]] to [[w:Diagnostic_and_Statistical_Manual_of_Mental_Disorders#DSM-IV-TR_.282000.29|DSM-5]]. Summaries are available [http://www.dsm5.org/Documents/changes%20from%20dsm-iv-tr%20to%20dsm-5.pdf here] and [[w:DSM-5|here]]. {{blockquotebottom}} === Base rates of anorexia nervosa in different populations and clinical settings === This section describes the demographic setting of the population(s) sampled, base rates of diagnosis such as prevalence rates, country/region sampled, and the diagnostic method that was used. Using this information, clinicians will be able to anchor the rate of adolescent depression that they are likely to see in their clinical practice. * '''''To see prevalence rates across multiple disorders,''''' [[Evidence based assessment/Preparation phase#Base rates for transdiagnostic comparison|'''''click here.''''']] {| class="wikitable sortable" |- ! Demography ! Setting (Reference) ! Base Rate ! Diagnostic Method |- |Nationally representative US sample of adults |Non-clinical: Population-based (NCS-R)<ref>Hudson, James I.; Hiripi, Eva; Pope, Harrison G.; Kessler, Ronald C. (2007-02-01). "The prevalence and correlates of eating disorders in the National Comorbidity Survey Replication".''Biological Psychiatry'' '''61''' (3): 348–358. doi:10.1016/j.biopsych.2006.03.040. ISSN 0006-3223. PMC 1892232. <nowiki>PMID 16815322</nowiki></ref> |.9% Female, .3% Male |World Health Organization-Clinical International Diagnostic Interview (WHO-CIDI) |- |Nationally representative US sample of adolescents |Non-clinical: Population-based (NCS-A)<ref>Swanson, Sonja A.; Crow, Scott J.; Le Grange, Daniel; Swendsen, Joel; Merikangas, Kathleen R. (2011-07-01). "Prevalence and correlates of eating disorders in adolescents. Results from the national comorbidity survey replication adolescent supplement". ''Archives of General Psychiatry'' '''68''' (7): 714–723. doi:10.1001/archgenpsychiatry.2011.22. ISSN 1538-3636.<nowiki>PMID 21383252</nowiki></ref> |.3% Female, .3% Male |WHO-CIDI |- |Nationally representative US sample of 9- and 10-year old children |Non-clinical: US Population-based prevalence (Adolescent Brain Cognitive Development (ABCD) study<ref>{{Cite journal|last=Rozzell|first=Kaitlin|last2=Moon|first2=Da Yeoun|last3=Klimek|first3=Patrycja|last4=Brown|first4=Tiffany|last5=Blashill|first5=Aaron J.|date=2019-01-01|title=Prevalence of Eating Disorders Among US Children Aged 9 to 10 Years: Data From the Adolescent Brain Cognitive Development (ABCD) Study|url=http://archpedi.jamanetwork.com/article.aspx?doi=10.1001/jamapediatrics.2018.3678|journal=JAMA Pediatrics|language=en|volume=173|issue=1|pages=100|doi=10.1001/jamapediatrics.2018.3678|issn=2168-6203|pmc=PMC6583451|pmid=30476983}}</ref> |0.1%, no gender differences |DSM-5 using Kiddie Schedule for Affective Disorders and Schizophrenia (KSADS) |- |Latino Households in the US |Non-clinical: Latinos in US<ref>Alegria, Margarita; Woo, Meghan; Cao, Zhun; Torres, Maria; Meng, Xiao-li; Striegel-Moore, Ruth (2007-11-01). "Prevalence and correlates of eating disorders in Latinos in the United States".''The International Journal of Eating Disorders''. 40 Suppl: S15–21. doi:10.1002/eat.20406. ISSN 0276-3478. PMC 2680162. <nowiki>PMID 17584870</nowiki></ref> |.12% Female, .03% Male |WHO-CIDI |- |National probability sample of adult and adolescent African Americans and Caribbean Blacks |Non-clinical: African Americans and Caribbean Blacks in the US (NSAL)<ref>Taylor, Jacquelyn Y.; Caldwell, Cleopatra Howard; Baser, Raymond E.; Faison, Nakesha; Jackson, James S. (2007-11-01). "Prevalence of eating disorders among Blacks in the National Survey of American Life". ''The International Journal of Eating Disorders''. 40 Suppl: S10–14. doi:10.1002/eat.20451. ISSN 0276-3478. PMC 2882704. <nowiki>PMID 17879287</nowiki></ref> |.14% Female, .2% Male |WHO-CIDI |- |Asian American adults in US households |Non-clinical: National Latino and Asian American Study (NLAAS) |.12% Female, .05% Male |WHO-CIDI |- | US African American college females | Non-clinical; college students<ref>Tyler ID. A true picture of eating disorders among African American women: a review of literature. ABNF J. 2003;14(3):73-4.</ref> || .0% || Eating Disorder Diagnostic Questionnaire (EDD-Q) |- | US Female Adolescents | Non-clinical; Adolescents<ref>Stice, E., Becker, C. B., & Yokum, S. (2013). Eating disorder prevention: Current evidence-base and future directions. ''Int. J. Eat. Disord. International Journal of Eating Disorders,'' ''46''(5), 478-485.</ref> || .8% || Eating Disorder Diagnosis Interview (EDDI) |- | US Division-I Varsity Student Athletes | Non-clinical; student-athletes<ref>Johnson C, Powers PS, Dick R. Athletes and eating disorders: the national collegiate athletic association study. Int J Eat Disord 1999;26:179e88.</ref> || .0% || Eating Disorder Inventory-2 (EDI-2) |- | Active duty females in US Army, Navy, Airforce, and Marines | Non-clinical; Military<ref>McNulty, PAF. (2001). Prevalence and contributing factors of eating disorder behaviors in active duty service women in the Army, Navy, Air Force and Marines. Military Medicine, 166(1), 53-58. </ref> || 1.1% || EDI-2 |- |US Caucasian female same-sex twins |Non-clinical; Commonwealth of Virginia Mid-Atlantic Twin Registry (MATR)<ref>Kendler KS, Walters EE, Neale MC, Kessler R, Heath A, Eaves L. The structure of genetic and environmental risk factors for six major psychiatric disorders in women. Archives of general psychiatry. 1995;52:374–383.</ref> |1.62% (narrow), 3.70% (broad) |Structured Clinical Interview for DSM Disorders (SCID) |- |South Australian older adolescents and adults |Non-clinical; Health Omnibus Survey (HOS) |.46% (3 months; combined) |Eating Disorder Examination (EDE) |- |US Military |Military<ref>{{Cite journal|title=Diagnosed eating disorders in the U.S. Military: a nine year review|url=http://www.ncbi.nlm.nih.gov/pubmed/18821361|journal=Eating Disorders|date=2008-12-01|issn=1532-530X|pmid=18821361|pages=363–377|volume=16|issue=5|doi=10.1080/10640260802370523|first=Amanda J.|last=Antczak|first2=Teresa L.|last2=Brininger}}</ref> |.04% (combined) |ICD codes from electronic records |- |US Military Academy cadets |Non-clinical; Military |.02% (7 years) Female, 0.0% (7 years) Males |[https://www.eat-26.com/ Eating Attitudes Test- 26 items] (EAT-26)<ref>{{Cite web|url=https://www.eat-26.com/|title=EAT-26: Eating Attitudes Test & Eating Disorder Testing – Use the EAT-26 to help you determine if you need to speak to a mental health professional to get help for an eating disorder.|last=admin|language=en|access-date=2022-05-30}}</ref> |- |US Navy female nurses |Non-clinical; Military |1.1% (current & past) Female |DSM-III |- |US veterans |Non-clinical; Military |.04% Female, .005% Males |ICD-9-CM |- |Active duty males in US Navy |Non-clinical; Military |2.5% Males |N/A |- |US alcohol-dependent adults from San Diego, St. Lois, Iowa City, Farmington, New York, & Indianapolis |Clinical; Collaborative Study on the Genetics of Alcoholism (COGA)<ref>{{Cite journal|title=Anorexia nervosa and bulimia nervosa in alcohol-dependent men and women and their relatives|url=http://www.ncbi.nlm.nih.gov/pubmed/8540597|journal=The American Journal of Psychiatry|date=1996-01-01|issn=0002-953X|pmid=8540597|pages=74–82|volume=153|issue=1|doi=10.1176/ajp.153.1.74|first=M. A.|last=Schuckit|first2=J. E.|last2=Tipp|first3=R. M.|last3=Anthenelli|first4=K. K.|last4=Bucholz|first5=V. M.|last5=Hesselbrock|first6=J. I.|last6=Nurnberger}}</ref> |1.41% (lifetime) Female, .00% (lifetime) Male |SSAGA |- |Healthcare provider records |Non-clinical; healthcare members |.0269% (current) | |- |US high school students in west central Oregon |Non-clinical; high school students |. 00% (point), .45% (lifetime) Female .00% (point), .00% (lifetime) Males |DSM-III-R₄ |- |Canadian treatment-seeking substance users |Clinical; substance users |.4% (lifetime), .3% (current) Female .4% (lifetime), .3% (current) Males |DIS₉ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''Europe''' |- |Adolescent females residing in Navarra, Spain |Non-clinical; adolescents |.3% Female |EAT-40₃ |- |Adolescents in secondary schools in Sør-Trøndelag, County in Norway |Non-clinical; adolescents |.7% (lifetime) Female, .2% Male |SEDs₁₀ |- |Adolescents in a comprehensive school in Ostrobothnia district in Finland |Non-clinical; adolescents |.7% (point; age 15), 1.8% (lifetime, age 15), .00% (point, age 18), 2.6% (lifetime, age 18), .9% (3 years) Female .00% (point & lifetime) Males |RAB-T₁₁&nbsp;& RAB-R₁₂ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''Australia''' |- |Adolescent females residing in Victoria, Australia |Non-clinical; adolescents |.00% (full), 1.8% (partial) Female |BET₁₃ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''Central & South America''' |- |Mexican first & second year college females |Non-clinical; college students |.00% Female |EAT-40₃ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''East Asia''' |- |Adolescent and adult Japanese patients at a university hospital |Clinical; eating disorder patients |.53% Female |DSM-III-R₄ |- |Korean adults |Non-clinical; Korean Epidemiologic Catchment Area (KECA) Study |.1% (lifetime), .1% (12 months) Female .2% (lifetime), .00% (12 months) Males |K-CIDI₁₅&nbsp;2.1 |- |Alcohol-dependent adults |Centers participating in the Collaborative Study on the Genetics of Alcoholism in San Diego; St. Louis; Iowa City; Farmington, CN; New York; & Indianapolis |1.41% Females |Semi-Structured Assessment for the Genetics of Alcoholism; criteria based on DSM-III-R |} ==[[Evidence based assessment/Prediction phase|'''Prediction phase''']]== === Psychometric properties of screening instruments for anorexia nervosa === The following section contains a list of screening and diagnostic instruments for anorexia nerova. The section includes administration information, psychometric data, and PDFs or links to the screenings. * Screenings are used as part of the [[Evidence based assessment/Prediction phase|prediction phase]] of assessment; for more information on interpretation of this data, or how screenings fit in to the assessment process, click [[Evidence based assessment/Prediction phase|here.]] * ''For a list of more broadly reaching screening instruments, [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prediction_phase&wteswitched=1#Psychometric_properties_of_common_screening_instruments '''click here.''']'' {| class="wikitable" |- ! Measure !Format (Reporter) !Age Range !Administration/ Completion Time !Where to Access |- |[[wikipedia:Eating_Disorder_Examination_Interview|Eating Disorder Examination Questionnaire (EDE-Q)]] |Questionnaire (Patient) |14+ |15-20 min | [http://www.corc.uk.net/media/1273/ede-q_quesionnaire.pdf PDF] |- |[[wikipedia:Eating_Disorder_Diagnostic_Scale|EDDS (Eating Disorder Diagnosis Scale)]]<ref>{{Cite journal|last=Stice|first=Eric|last2=Telch|first2=Christy F.|last3=Rizvi|first3=Shireen L.|date=2000|title=Development and validation of the Eating Disorder Diagnostic Scale: A brief self-report measure of anorexia, bulimia, and binge-eating disorder.|url=http://doi.apa.org/getdoi.cfm?doi=10.1037/1040-3590.12.2.123|journal=Psychological Assessment|language=en|volume=12|issue=2|pages=123–131|doi=10.1037/1040-3590.12.2.123|issn=1939-134X}}</ref> |Questionnaire (Patient) |13 - 65 |10-15 min | [http://www.ori.org/files/Static%20Page%20Files/EDDSDSM-5_10_14.pdf PDF] |- |Eating Attitudes Test- 26(EAT-26; Adult version)<ref>{{Cite journal|last=Garner|first=David M.|last2=Garfinkel|first2=Paul E.|date=1979-05|title=The Eating Attitudes Test: an index of the symptoms of anorexia nervosa|url=http://dx.doi.org/10.1017/s0033291700030762|journal=Psychological Medicine|volume=9|issue=2|pages=273–279|doi=10.1017/s0033291700030762|issn=0033-2917}}</ref> Child Eating Attitudes Test - 26 (ChEAT-26; child version)<ref>{{Cite journal|last=Almeida|first=M.C.|last2=Carvalho|first2=D.L.D.B.|last3=Rigolino|first3=R.|date=2012-07|title=Reliability of a Brazilian version of children's eating attitude test|url=http://dx.doi.org/10.1016/j.neurenf.2012.04.196|journal=Neuropsychiatrie de l'Enfance et de l'Adolescence|volume=60|issue=5|pages=S158|doi=10.1016/j.neurenf.2012.04.196|issn=0222-9617}}</ref> |Questionnaire (Patient) |13+ (adult version) 8 -13 (child version) |5-10 min |PDFs * [https://www.eat-26.com/eat-26/ Adult Version PDF] * [http://www.1000livesplus.wales.nhs.uk/sitesplus/documents/1011/ChEAT.pdf Child Version PDF] |} <ref>Hunsley, J., & Mash, E. J. (2008). Guide to Assessments that Work. Cary, NC, USA: Oxford University Press, USA. Retrieved from <nowiki>http://www.ebrary.com</nowiki></ref>'''Note:''' '''L''' = Less than adequate; '''A''' = Adequate; '''G''' = Good; '''E''' = Excellent; '''U''' = Unavailable; '''NA''' = Not applicable ===Likelihood ratios and AUCs of screening instruments for anorexia nervosa=== * ''For a list of the likelihood ratios for more broadly reaching screening instruments, [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prediction_phase&wteswitched=1#Likelihood_ratios_and_AUCs_of_common_screening_instruments '''click here.''']'' {| class="wikitable sortable" border="1" |- ! <ref name=":4">{{Cite journal|last=Mintz|first=L. B.|last2=O'Halloran|first2=M. S.|date=June 2000|title=The Eating Attitudes Test: validation with DSM-IV eating disorder criteria|url=https://www.ncbi.nlm.nih.gov/pubmed/10900574|journal=Journal of Personality Assessment|volume=74|issue=3|pages=489–503|doi=10.1207/S15327752JPA7403_11|issn=0022-3891|pmid=10900574}}</ref>Screening Measure (Primary Reference) ! AUC ! DiLR+ (Score) ! DiLR- (Score) !Clinical Generalizability !Where to access |- |Serum leptin level<ref name=":7">{{Cite journal|last=Föcker|first=M.|last2=Timmesfeld|first2=N.|last3=Scherag|first3=S.|last4=Bühren|first4=K.|last5=Langkamp|first5=M.|last6=Dempfle|first6=A.|last7=Sheridan|first7=E. M.|last8=Zwaan|first8=M. de|last9=Fleischhaker|first9=C.|date=2011-04-01|title=Screening for anorexia nervosa via measurement of serum leptin levels|url=https://link.springer.com/article/10.1007/s00702-010-0551-z|journal=Journal of Neural Transmission|language=en|volume=118|issue=4|pages=571–578|doi=10.1007/s00702-010-0551-z|issn=0300-9564}}</ref> |0.984 (N=139) |14.72 (<2.31) |0.10 (2.31+) |Adolescent and adult patients in the acute phase of AN according to the DSM-IV and no AN pretreatment versus healthy lean female volunteer university students. |None |- |Body Mass Index (BMI)<ref name=":7" /> |0.936 (N=139) |5.89 (<17.10) |0.11 (17.10+) |Adolescent and adult patients in the acute phase of AN according to the DSM-IV and no AN pretreatment versus healthy lean female volunteer university students. |None |- |EAT-26&nbsp;<ref name=":4" /><ref>{{Cite journal|title = The eating attitudes test: psychometric features and clinical correlates|url = http://www.ncbi.nlm.nih.gov/pubmed/6961471|journal = Psychological Medicine|date = 1982-11-01|issn = 0033-2917|pmid = 6961471|pages = 871–878|volume = 12|issue = 4|first = D. M.|last = Garner|first2 = M. P.|last2 = Olmsted|first3 = Y.|last3 = Bohr|first4 = P. E.|last4 = Garfinkel}}</ref> |.90 (N=129) |12.83 (20+) |.24 (<20) |Low-moderate: College women with no eating disorder versus college women with a DSM-IV eating disorder. Eating disorders were not separated. |[https://www.eat-26.com/eat-26/ Adult Version PDF][http://www.1000livesplus.wales.nhs.uk/sitesplus/documents/1011/ChEAT.pdf Child Version PDF] |- |EDE-Q&nbsp;<ref name=":1">{{Cite journal|title = Assessment of eating disorders: interview or self-report questionnaire?|url = http://www.ncbi.nlm.nih.gov/pubmed/7866415|journal = The International Journal of Eating Disorders|date = 1994-12-01|issn = 0276-3478|pmid = 7866415|pages = 363–370|volume = 16|issue = 4|first = C. G.|last = Fairburn|first2 = S. J.|last2 = Beglin}}</ref> |.96 &nbsp;<ref name=":1" />(N=1170) | 6.57 (2.3+)<ref name=":5">{{Cite journal|last=Fairburn|first=C. G.|last2=Beglin|first2=S. J.|date=December 1994|title=Assessment of eating disorders: interview or self-report questionnaire?|url=https://www.ncbi.nlm.nih.gov/pubmed/7866415|journal=The International Journal of Eating Disorders|volume=16|issue=4|pages=363–370|issn=0276-3478|pmid=7866415}}</ref> | 0.09 (<2.3)<ref name=":5" /> |Moderate: Dutch treatment-seeking females meeting DSM-IV criteria for an eating disorder versus female adult general population sample recruited through advertisements and personal contacts. Eating disorders were not separated.&nbsp;<ref name=":1" /> Moderate: “Clinically significant eating disorder” from a community sample versus female adults individuals without “clinically significant eating disorder” from same sample. Eating disorders were not separated.<ref name=":5" /> |[http://www.corc.uk.net/media/1273/ede-q_quesionnaire.pdf PDF] |} === Interpreting anorexia nervosa screening measure scores === * For information on interpreting screening measure scores, click [[Evidence based assessment/Prediction phase#Interpreting screening measure scores|here.]] * Also see the page on [https://en.wikipedia.org/wiki/Likelihood_ratios_in_diagnostic_testing likelihood ratios in diagnostic testing] for more information. ==[[Evidence based assessment/Prescription phase|'''Prescription phase''']]== ===Gold standard diagnostic interviews=== * For a list of broad reaching diagnostic interviews sortable by disorder with PDFs (if applicable), [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prescription_phase&wteswitched=1#Common_Diagnostic_Interviews click here.] ===Recommended diagnostic interviews for anorexia nervosa=== {| class="wikitable sortable" border="1" ! colspan="5" |Diagnostic instruments for anorexia nervosa |- ! Measure ! Format (Reporter) ! Age Range ! Administration/ Completion Time !Where to access |- |[https://www.credo-oxford.com/7.2.html Eating Disorder Examination (EDE)] <ref>{{Cite book|url=https://www.worldcat.org/oclc/1160972551|title=Assessment of disorders in childhood and adolescence|date=2020|others=Eric Arden Youngstrom, Mitchell J. Prinstein, Eric J. Mash, Russell A. Barkley|isbn=978-1-4625-4365-6|edition=Fifth edition|location=New York|oclc=1160972551}}</ref> <ref>{{Cite book|url=https://www.worldcat.org/oclc/314222270|title=A guide to assessments that work|date=2008|publisher=Oxford University Press|others=John Hunsley, Eric J. Mash|isbn=0-19-804245-0|location=New York|oclc=314222270}}</ref> |Semistructured (child and adult) |8-16 (child version) 16+ (adult version) |45-75 minutes |[https://www.phenxtoolkit.org/protocols/view/230101 Child version PDF][https://www.credo-oxford.com/7.2.html Adult version PDF][https://osf.io/eytc5 PDF] |- |Structured Clinical Interview for DSM-5-Clinician Version (SCID-5-CV)<ref>{{Cite journal|last=Shabani|first=Amir|last2=Masoumian|first2=Samira|last3=Zamirinejad|first3=Somayeh|last4=Hejri|first4=Maryam|last5=Pirmorad|first5=Tahereh|last6=Yaghmaeezadeh|first6=Hooman|date=2021-05|title=Psychometric properties of Structured Clinical Interview for DSM‐5 Disorders‐Clinician Version (SCID‐5‐CV)|url=https://onlinelibrary.wiley.com/doi/10.1002/brb3.1894|journal=Brain and Behavior|language=en|volume=11|issue=5|doi=10.1002/brb3.1894|issn=2162-3279|pmc=PMC8119811|pmid=33729681}}</ref> |Structured Interview (Adult ) |16+ |Varies |[https://www.columbiapsychiatry.org/research/research-labs/diagnostic-and-assessment-lab/structured-clinical-interview-dsm-disorders-11 Website to purchase] |- | [https://dawba.info/a0.html Development and Well-Being Assessment (DAWBA)] <ref>{{Cite book|url=https://www.worldcat.org/oclc/1160972551|title=Assessment of disorders in childhood and adolescence|date=2020|others=Eric Arden Youngstrom, Mitchell J. Prinstein, Eric J. Mash, Russell A. Barkley|isbn=978-1-4625-4365-6|edition=Fifth edition|location=New York|oclc=1160972551}}</ref> | Structured (child/adolescent and parent) | 11-18 |10-20 minutes for the eating disorder module |[https://osf.io/zpbna/?view_only=245bef061d284c17ab9dedad5a59e1b8 English PDF] [https://dawba.info/py/dawbainfo/b1.py Additional languages] |} '''Note:''' '''L''' = Less than adequate; '''A''' = Adequate; '''G''' = Good; '''E''' = Excellent; '''U''' = Unavailable; '''NA''' = Not applicable ==[[Evidence based assessment/Process phase|'''Process phase''']]== The following section contains a brief overview of treatment options for anorexia nervosa and a list of process and outcome measures for anorexia nervosa. The section includes benchmarks based on published norms for several outcome and severity measures, as well as information about commonly used process measures. Process and outcome measures are used as part of the [[Evidence based assessment/Process phase|process phase]] of assessment. For more information on the differences between process and outcome measures, see the page on the [[Evidence based assessment/Process phase|process phase of assessment]]. ===Process measures=== Body weight is commonly monitored by clinicians throughout the AN treatment process as helping individuals regain and maintain a healthy weight is a primary treatment goal for AN. Many treatment centers have policies prohibiting patients from seeing their weight. Motivational Stages of Change may be used to monitor individuals’ readiness to take action against eating disorder behaviors. It has demonstrated predictive validity in a sample of female adolescents attending eating disorder treatment groups.<ref>{{Cite journal|last=Gusella|first=Joanne|last2=Butler|first2=Gordon|last3=Nichols|first3=Laura|last4=Bird|first4=Debbie|date=2003-01-01|title=A brief questionnaire to assess readiness to change in adolescents with eating disorders: its applications to group therapy|url=http://onlinelibrary.wiley.com/doi/10.1002/erv.481/abstract|journal=European Eating Disorders Review|language=en|volume=11|issue=1|pages=58–71|doi=10.1002/erv.481|issn=1099-0968}}</ref> See Appendix E. === Outcome and severity measures === This table includes clinically significant benchmarks for anorexia nervosa specific outcome measures * Information on how to interpret this table can be [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Process_phase found here]. * Additionally, these [[Evidence based assessment/Vignettes|vignettes]] might be helpful resources for understanding appropriate adaptation of outcome measures in practice. *''<u>For clinically significant change benchmarks for the CBCL, YSR, and TRF total, externalizing, internalizing, and attention benchmarks,</u>'' [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Process_phase&wteswitched=1#Clinically_significant_change_benchmarks_for_widely-used_outcome_measures see here.] {| class="wikitable sortable" border="1" | colspan="8" |'''Clinically significant change benchmarks with common instruments for anorexia nervosa''' |- | colspan="8" span style="font-size:110%; text-align:center;" | <b> Benchmarks Based on Published Norms</b> |- | rowspan="2" style="text-align:center;font-size:130%;" |<b> Measure</b> | rowspan="2" style="text-align:center;font-size:130%;" | <b> Subscale</b> | colspan="3" style="text-align:center;font-size:130%" width="300" | <b> Cut-off scores</b> | colspan="3" style="text-align:center;font-size:120%" | <b> Critical Change <br> (unstandardized scores)</b> |- | style="text-align:center;font-size:110%" |<b> A</b> | style="text-align:center;font-size:110%" |<b> B</b> | style="text-align:center;font-size:110%" |<b> C</b> | style="text-align:center;font-size:110%" |<b> 95%</b> | style="text-align:center;font-size:110%" |<b> 90%</b> | style="text-align:center;font-size:110%" |<b> SE_difference</b> |- | rowspan="5" style="text-align:center;" |'''EDE-Q <ref name=":2">{{Cite journal|last=Mond|first=J. M.|last2=Hay|first2=P. J.|last3=Rodgers|first3=B.|last4=Owen|first4=C.|last5=Beumont|first5=P. J. V.|date=May 2004|title=Validity of the Eating Disorder Examination Questionnaire (EDE-Q) in screening for eating disorders in community samples|url=https://www.ncbi.nlm.nih.gov/pubmed/15033501|journal=Behaviour Research and Therapy|volume=42|issue=5|pages=551–567|doi=10.1016/S0005-7967(03)00161-X|issn=0005-7967|pmid=15033501}}</ref>''' | style="text-align:right;" |''Global'' |1.4 |3.2 |2.3 |.7 |.6 |.3 |- | style="text-align:right;" |''Restraint'' |(-.3) |3.6 |1.8 |1.5 |1.2 |.8 |- | style="text-align:right;" |''Eating Concern'' |.1 |2.0 |1.2 |1.1 |.9 |.6 |- | style="text-align:right;" |''Weight Concern'' |1.5 |3.9 |2.6 |1.0 |.9 |.5 |- | style="text-align:right;" |''Shape Concern'' |2.1 |4.8 |3.2 |.9 |.7 |.4 |- | rowspan="5" style="text-align:center;" |'''EDE <ref name=":2" />''' | style="text-align:right;" |''Global'' |1.7 |2.3 |1.9 |1.9 |1.6 |1.0 |- | style="text-align:right;" |''Restraint'' |.3 |3.3 |1.9 |1.8 |1.5 |.9 |- | style="text-align:right;" |''Eating Concern'' |(-.5) |.9 |.5 |.8 |.7 |.4 |- | style="text-align:right;" |''Weight Concern'' |2.0 |2.8 |2.4 |1.3 |1.1 |.7 |- | style="text-align:right;" |''Shape Concern'' |2.0 |3.2 |2.6 |1.2 |1.0 |.6 |- | rowspan="1" style="text-align:center;" |'''EAT-26 <ref name=":0">{{Cite journal|last=Mintz|first=L. B.|last2=O'Halloran|first2=M. S.|date=2000-06-01|title=The Eating Attitudes Test: validation with DSM-IV eating disorder criteria|url=http://www.ncbi.nlm.nih.gov/pubmed/10900574|journal=Journal of Personality Assessment|volume=74|issue=3|pages=489–503|doi=10.1207/S15327752JPA7403_11|issn=0022-3891|pmid=10900574}}</ref>''' | style="text-align:right;" |''Total'' |6.5 |19.6 |15.0 |7.9 |6.7 |4.0 |} '''Note:''' “A” = Away from the clinical range, “B” = Back into the nonclinical range, “C” = Closer to the nonclinical than clinical mean. '''Search terms:''' [Anorexia Nervosa OR eating disorder] AND [validity OR clinical significance] in Google Scholar === Treatment === {{collapse top| Click here for more information on treatment for AN}} * Treatment of AN typically consists of restoring the individual to a healthy weight and addressing thoughts and behaviors which are related to the eating disorder. It may involve re-nutrition, psychotherapy, nutritional counseling, and medication. * Literature reviews of existing research indicate that evidence supporting AN treatment is lacking. A systematic review of AN treatment efficacy studies by Bulik<ref>{{Cite journal|title = Anorexia nervosa treatment: a systematic review of randomized controlled trials|url = http://www.ncbi.nlm.nih.gov/pubmed/17370290|journal = The International Journal of Eating Disorders|date = 2007-05-01|issn = 0276-3478|pmid = 17370290|pages = 310–320|volume = 40|issue = 4|doi = 10.1002/eat.20367|first = Cynthia M.|last = Bulik|first2 = Nancy D.|last2 = Berkman|first3 = Kimberly A.|last3 = Brownley|first4 = Jan A.|last4 = Sedway|first5 = Kathleen N.|last5 = Lohr}}</ref> found that evidence supporting medications, medications and behavioral interventions, and behavioral interventions alone in adults is weak. * There is moderately strong evidence suggesting that behavioral interventions may be helpful for adolescents. In particular, adolescents may benefit from family therapy. * Clinical trials investigating AN treatment suffer from high rates of attrition, as key features of AN (e.g., denial, fear of weight gain) may contribute to low motivation for remaining in treatment. * More severe cases of AN may be treated in inpatient settings, which are equipped to manage the re-nutrition process and provide medical monitoring. * Partial hospitalization and intensive outpatient programs may provide intermediate levels of treatment intensity to assist individuals in the transition from intensive care to outpatient care after weight restoration. {{collapse bottom}} * Please refer to the page on [https://en.wikipedia.org/wiki/Anorexia_nervosa anorexia nervosa] for more information on available treatment or go to [http://effectivechildtherapy.org/concerns-symptoms-disorders/disorders/eating-body-image-problems/ the Effective Child Therapy page for Eating & Body Image Problems] for a curated resource on effective treatments for anorexia nervosa. == '''External resources''' == # [http://apps.who.int/classifications/icd10/browse/2010/en#/F50.0 ICD-10 diagnostic criteria] # [https://en.wikiversity.org/w/index.php?title=Helping_Give_Away_Psychological_Science/Resources/Annotated_List_of_Where_and_How_to_Find_a_Therapist&wteswitched=1#Other_low-cost_options Find-a-Therapist] ##This is a curated list of find-a-therapist websites where you can find a provider # NIMH: [https://www.nimh.nih.gov/health/publications/eating-disorders/index.shtml ''Eating Disorders--About More Than Food''] and [https://www.nimh.nih.gov/health/topics/eating-disorders/index.shtml ''Eating Disorders''] ##These NIMH website posts provide more information on anorexia nervosa #[https://www.hopkinsmedicine.org/psychiatry/specialty_areas/eating_disorders/ John's Hopkins Resource] (guide about anorexia nervosa, treatment, and more) # OMIM (Online Mendelian Inheritance in Man) ##[https://www.omim.org/entry/606788?search=anorexia%20nervosa&highlight=nervosa%20anorexia Anorexia nervosa] #[http://effectivechildtherapy.org/concerns-symptoms-disorders/disorders/eating-body-image-problems/ Effective Child Therapy page for anorexia nervosa] ##Effective Child Therapy is website sponsored by Division 53 of the American Psychological Association (APA), or The [https://sccap53.org Society of Clinical Child and Adolescent Psychology] (SCCAP), in collaboration with the Association for Behavioral and Cognitive Therapies (ABCT). Use for information on symptoms and available treatments. == '''References''' == {{collapse top|Click here for references}} {{Reflist|30em}} [[Category:Psychological disorder portfolios|{{SUBPAGENAME}}]] {{collapse bottom}} k4d9aocv7ddbts0k6hi0f2ek7c49lzs 2413985 2413984 2022-08-12T15:43:36Z Aherman012 2943941 /* Psychometric properties of screening instruments for anorexia nervosa */ wikitext text/x-wiki <noinclude>{{Helping Give Away Psychological Science Banner}}</noinclude> {{medical disclaimer}} {{:{{BASEPAGENAME}}/Sidebar}} ==[[Evidence based assessment/Portfolio template/What is a "portfolio"|'''What is a "portfolio"?''']]== For background information on what assessment portfolios are, click the link in the heading above. Want even 'more' information about this topic? There's an extended version of this page [[Evidence-based assessment/Anorexia nervosa (assessment portfolio)/extended version|here]]. == [[Evidence based assessment/Preparation phase|'''Preparation phase''']] == === Diagnostic criteria for anorexia nervosa === {{blockquotetop}} '''ICD-11 Criteria''' Anorexia Nervosa is characterized by significantly low body weight, which is less than minimal normal/expected weight for the individual’s height, sex, age and developmental stage (body mass index (BMI) less than 18.5 kg/m2 in adults and BMI-for-age under fifth percentile in children and adolescents) that is not due to another health condition or to the unavailability of food. Low body weight is accompanied by a persistent pattern of behaviors to prevent restoration of normal weight, which may include behaviors aimed at reducing energy intake (restricted eating), purging behaviors (e.g., self-induced vomiting, misuse of laxatives), and behaviors aimed at increasing energy expenditure (e.g., excessive exercise), typically associated with a fear of weight gain. Low body weight or shape is central to the person's self-evaluation or is inaccurately perceived to be normal or even excessive. '''Changes in DSM-5''' * The diagnostic criteria for anorexia nervosa changed slightly from [[DSM-IV]] to [[w:Diagnostic_and_Statistical_Manual_of_Mental_Disorders#DSM-IV-TR_.282000.29|DSM-5]]. Summaries are available [http://www.dsm5.org/Documents/changes%20from%20dsm-iv-tr%20to%20dsm-5.pdf here] and [[w:DSM-5|here]]. {{blockquotebottom}} === Base rates of anorexia nervosa in different populations and clinical settings === This section describes the demographic setting of the population(s) sampled, base rates of diagnosis such as prevalence rates, country/region sampled, and the diagnostic method that was used. Using this information, clinicians will be able to anchor the rate of adolescent depression that they are likely to see in their clinical practice. * '''''To see prevalence rates across multiple disorders,''''' [[Evidence based assessment/Preparation phase#Base rates for transdiagnostic comparison|'''''click here.''''']] {| class="wikitable sortable" |- ! Demography ! Setting (Reference) ! Base Rate ! Diagnostic Method |- |Nationally representative US sample of adults |Non-clinical: Population-based (NCS-R)<ref>Hudson, James I.; Hiripi, Eva; Pope, Harrison G.; Kessler, Ronald C. (2007-02-01). "The prevalence and correlates of eating disorders in the National Comorbidity Survey Replication".''Biological Psychiatry'' '''61''' (3): 348–358. doi:10.1016/j.biopsych.2006.03.040. ISSN 0006-3223. PMC 1892232. <nowiki>PMID 16815322</nowiki></ref> |.9% Female, .3% Male |World Health Organization-Clinical International Diagnostic Interview (WHO-CIDI) |- |Nationally representative US sample of adolescents |Non-clinical: Population-based (NCS-A)<ref>Swanson, Sonja A.; Crow, Scott J.; Le Grange, Daniel; Swendsen, Joel; Merikangas, Kathleen R. (2011-07-01). "Prevalence and correlates of eating disorders in adolescents. Results from the national comorbidity survey replication adolescent supplement". ''Archives of General Psychiatry'' '''68''' (7): 714–723. doi:10.1001/archgenpsychiatry.2011.22. ISSN 1538-3636.<nowiki>PMID 21383252</nowiki></ref> |.3% Female, .3% Male |WHO-CIDI |- |Nationally representative US sample of 9- and 10-year old children |Non-clinical: US Population-based prevalence (Adolescent Brain Cognitive Development (ABCD) study<ref>{{Cite journal|last=Rozzell|first=Kaitlin|last2=Moon|first2=Da Yeoun|last3=Klimek|first3=Patrycja|last4=Brown|first4=Tiffany|last5=Blashill|first5=Aaron J.|date=2019-01-01|title=Prevalence of Eating Disorders Among US Children Aged 9 to 10 Years: Data From the Adolescent Brain Cognitive Development (ABCD) Study|url=http://archpedi.jamanetwork.com/article.aspx?doi=10.1001/jamapediatrics.2018.3678|journal=JAMA Pediatrics|language=en|volume=173|issue=1|pages=100|doi=10.1001/jamapediatrics.2018.3678|issn=2168-6203|pmc=PMC6583451|pmid=30476983}}</ref> |0.1%, no gender differences |DSM-5 using Kiddie Schedule for Affective Disorders and Schizophrenia (KSADS) |- |Latino Households in the US |Non-clinical: Latinos in US<ref>Alegria, Margarita; Woo, Meghan; Cao, Zhun; Torres, Maria; Meng, Xiao-li; Striegel-Moore, Ruth (2007-11-01). "Prevalence and correlates of eating disorders in Latinos in the United States".''The International Journal of Eating Disorders''. 40 Suppl: S15–21. doi:10.1002/eat.20406. ISSN 0276-3478. PMC 2680162. <nowiki>PMID 17584870</nowiki></ref> |.12% Female, .03% Male |WHO-CIDI |- |National probability sample of adult and adolescent African Americans and Caribbean Black people |Non-clinical: African Americans and Caribbean Black people in the US (NSAL)<ref>Taylor, Jacquelyn Y.; Caldwell, Cleopatra Howard; Baser, Raymond E.; Faison, Nakesha; Jackson, James S. (2007-11-01). "Prevalence of eating disorders among Blacks in the National Survey of American Life". ''The International Journal of Eating Disorders''. 40 Suppl: S10–14. doi:10.1002/eat.20451. ISSN 0276-3478. PMC 2882704. <nowiki>PMID 17879287</nowiki></ref> |.14% Female, .2% Male |WHO-CIDI |- |Asian American adults in US households |Non-clinical: National Latino and Asian American Study (NLAAS) |.12% Female, .05% Male |WHO-CIDI |- | US African American college females | Non-clinical; college students<ref>Tyler ID. A true picture of eating disorders among African American women: a review of literature. ABNF J. 2003;14(3):73-4.</ref> || .0% || Eating Disorder Diagnostic Questionnaire (EDD-Q) |- | US Female Adolescents | Non-clinical; Adolescents<ref>Stice, E., Becker, C. B., & Yokum, S. (2013). Eating disorder prevention: Current evidence-base and future directions. ''Int. J. Eat. Disord. International Journal of Eating Disorders,'' ''46''(5), 478-485.</ref> || .8% || Eating Disorder Diagnosis Interview (EDDI) |- | US Division-I Varsity Student Athletes | Non-clinical; student-athletes<ref>Johnson C, Powers PS, Dick R. Athletes and eating disorders: the national collegiate athletic association study. Int J Eat Disord 1999;26:179e88.</ref> || .0% || Eating Disorder Inventory-2 (EDI-2) |- | Active duty females in US Army, Navy, Airforce, and Marines | Non-clinical; Military<ref>McNulty, PAF. (2001). Prevalence and contributing factors of eating disorder behaviors in active duty service women in the Army, Navy, Air Force and Marines. Military Medicine, 166(1), 53-58. </ref> || 1.1% || EDI-2 |- |US Caucasian female same-sex twins |Non-clinical; Commonwealth of Virginia Mid-Atlantic Twin Registry (MATR)<ref>Kendler KS, Walters EE, Neale MC, Kessler R, Heath A, Eaves L. The structure of genetic and environmental risk factors for six major psychiatric disorders in women. Archives of general psychiatry. 1995;52:374–383.</ref> |1.62% (narrow), 3.70% (broad) |Structured Clinical Interview for DSM Disorders (SCID) |- |South Australian older adolescents and adults |Non-clinical; Health Omnibus Survey (HOS) |.46% (3 months; combined) |Eating Disorder Examination (EDE) |- |US Military |Military<ref>{{Cite journal|title=Diagnosed eating disorders in the U.S. Military: a nine year review|url=http://www.ncbi.nlm.nih.gov/pubmed/18821361|journal=Eating Disorders|date=2008-12-01|issn=1532-530X|pmid=18821361|pages=363–377|volume=16|issue=5|doi=10.1080/10640260802370523|first=Amanda J.|last=Antczak|first2=Teresa L.|last2=Brininger}}</ref> |.04% (combined) |ICD codes from electronic records |- |US Military Academy cadets |Non-clinical; Military |.02% (7 years) Female, 0.0% (7 years) Males |[https://www.eat-26.com/ Eating Attitudes Test- 26 items] (EAT-26)<ref>{{Cite web|url=https://www.eat-26.com/|title=EAT-26: Eating Attitudes Test & Eating Disorder Testing – Use the EAT-26 to help you determine if you need to speak to a mental health professional to get help for an eating disorder.|last=admin|language=en|access-date=2022-05-30}}</ref> |- |US Navy female nurses |Non-clinical; Military |1.1% (current & past) Female |DSM-III |- |US veterans |Non-clinical; Military |.04% Female, .005% Males |ICD-9-CM |- |Active duty males in US Navy |Non-clinical; Military |2.5% Males |N/A |- |US alcohol-dependent adults from San Diego, St. Lois, Iowa City, Farmington, New York, & Indianapolis |Clinical; Collaborative Study on the Genetics of Alcoholism (COGA)<ref>{{Cite journal|title=Anorexia nervosa and bulimia nervosa in alcohol-dependent men and women and their relatives|url=http://www.ncbi.nlm.nih.gov/pubmed/8540597|journal=The American Journal of Psychiatry|date=1996-01-01|issn=0002-953X|pmid=8540597|pages=74–82|volume=153|issue=1|doi=10.1176/ajp.153.1.74|first=M. A.|last=Schuckit|first2=J. E.|last2=Tipp|first3=R. M.|last3=Anthenelli|first4=K. K.|last4=Bucholz|first5=V. M.|last5=Hesselbrock|first6=J. I.|last6=Nurnberger}}</ref> |1.41% (lifetime) Female, .00% (lifetime) Male |SSAGA |- |Healthcare provider records |Non-clinical; healthcare members |.0269% (current) | |- |US high school students in west central Oregon |Non-clinical; high school students |. 00% (point), .45% (lifetime) Female .00% (point), .00% (lifetime) Males |DSM-III-R₄ |- |Canadian treatment-seeking substance users |Clinical; substance users |.4% (lifetime), .3% (current) Female .4% (lifetime), .3% (current) Males |DIS₉ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''Europe''' |- |Adolescent females residing in Navarra, Spain |Non-clinical; adolescents |.3% Female |EAT-40₃ |- |Adolescents in secondary schools in Sør-Trøndelag, County in Norway |Non-clinical; adolescents |.7% (lifetime) Female, .2% Male |SEDs₁₀ |- |Adolescents in a comprehensive school in Ostrobothnia district in Finland |Non-clinical; adolescents |.7% (point; age 15), 1.8% (lifetime, age 15), .00% (point, age 18), 2.6% (lifetime, age 18), .9% (3 years) Female .00% (point & lifetime) Males |RAB-T₁₁&nbsp;& RAB-R₁₂ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''Australia''' |- |Adolescent females residing in Victoria, Australia |Non-clinical; adolescents |.00% (full), 1.8% (partial) Female |BET₁₃ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''Central & South America''' |- |Mexican first & second year college females |Non-clinical; college students |.00% Female |EAT-40₃ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''East Asia''' |- |Adolescent and adult Japanese patients at a university hospital |Clinical; eating disorder patients |.53% Female |DSM-III-R₄ |- |Korean adults |Non-clinical; Korean Epidemiologic Catchment Area (KECA) Study |.1% (lifetime), .1% (12 months) Female .2% (lifetime), .00% (12 months) Males |K-CIDI₁₅&nbsp;2.1 |- |Alcohol-dependent adults |Centers participating in the Collaborative Study on the Genetics of Alcoholism in San Diego; St. Louis; Iowa City; Farmington, CN; New York; & Indianapolis |1.41% Females |Semi-Structured Assessment for the Genetics of Alcoholism; criteria based on DSM-III-R |} ==[[Evidence based assessment/Prediction phase|'''Prediction phase''']]== === Psychometric properties of screening instruments for anorexia nervosa === The following section contains a list of screening and diagnostic instruments for anorexia nervosa. The section includes administration information, psychometric data, and PDFs or links to the screenings. * Screenings are used as part of the [[Evidence based assessment/Prediction phase|prediction phase]] of assessment; for more information on interpretation of this data, or how screenings fit in to the assessment process, click [[Evidence based assessment/Prediction phase|here.]] * ''For a list of more broadly reaching screening instruments, [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prediction_phase&wteswitched=1#Psychometric_properties_of_common_screening_instruments '''click here.''']'' {| class="wikitable" |- ! Measure !Format (Reporter) !Age Range !Administration/ Completion Time !Where to Access |- |[[wikipedia:Eating_Disorder_Examination_Interview|Eating Disorder Examination Questionnaire (EDE-Q)]] |Questionnaire (Patient) |14+ |15-20 min | [http://www.corc.uk.net/media/1273/ede-q_quesionnaire.pdf PDF] |- |[[wikipedia:Eating_Disorder_Diagnostic_Scale|EDDS (Eating Disorder Diagnosis Scale)]]<ref>{{Cite journal|last=Stice|first=Eric|last2=Telch|first2=Christy F.|last3=Rizvi|first3=Shireen L.|date=2000|title=Development and validation of the Eating Disorder Diagnostic Scale: A brief self-report measure of anorexia, bulimia, and binge-eating disorder.|url=http://doi.apa.org/getdoi.cfm?doi=10.1037/1040-3590.12.2.123|journal=Psychological Assessment|language=en|volume=12|issue=2|pages=123–131|doi=10.1037/1040-3590.12.2.123|issn=1939-134X}}</ref> |Questionnaire (Patient) |13 - 65 |10-15 min | [http://www.ori.org/files/Static%20Page%20Files/EDDSDSM-5_10_14.pdf PDF] |- |Eating Attitudes Test- 26(EAT-26; Adult version)<ref>{{Cite journal|last=Garner|first=David M.|last2=Garfinkel|first2=Paul E.|date=1979-05|title=The Eating Attitudes Test: an index of the symptoms of anorexia nervosa|url=http://dx.doi.org/10.1017/s0033291700030762|journal=Psychological Medicine|volume=9|issue=2|pages=273–279|doi=10.1017/s0033291700030762|issn=0033-2917}}</ref> Child Eating Attitudes Test - 26 (ChEAT-26; child version)<ref>{{Cite journal|last=Almeida|first=M.C.|last2=Carvalho|first2=D.L.D.B.|last3=Rigolino|first3=R.|date=2012-07|title=Reliability of a Brazilian version of children's eating attitude test|url=http://dx.doi.org/10.1016/j.neurenf.2012.04.196|journal=Neuropsychiatrie de l'Enfance et de l'Adolescence|volume=60|issue=5|pages=S158|doi=10.1016/j.neurenf.2012.04.196|issn=0222-9617}}</ref> |Questionnaire (Patient) |13+ (adult version) 8 -13 (child version) |5-10 min |PDFs * [https://www.eat-26.com/eat-26/ Adult Version PDF] * [http://www.1000livesplus.wales.nhs.uk/sitesplus/documents/1011/ChEAT.pdf Child Version PDF] |} <ref>Hunsley, J., & Mash, E. J. (2008). Guide to Assessments that Work. Cary, NC, USA: Oxford University Press, USA. Retrieved from <nowiki>http://www.ebrary.com</nowiki></ref>'''Note:''' '''L''' = Less than adequate; '''A''' = Adequate; '''G''' = Good; '''E''' = Excellent; '''U''' = Unavailable; '''NA''' = Not applicable ===Likelihood ratios and AUCs of screening instruments for anorexia nervosa=== * ''For a list of the likelihood ratios for more broadly reaching screening instruments, [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prediction_phase&wteswitched=1#Likelihood_ratios_and_AUCs_of_common_screening_instruments '''click here.''']'' {| class="wikitable sortable" border="1" |- ! <ref name=":4">{{Cite journal|last=Mintz|first=L. B.|last2=O'Halloran|first2=M. S.|date=June 2000|title=The Eating Attitudes Test: validation with DSM-IV eating disorder criteria|url=https://www.ncbi.nlm.nih.gov/pubmed/10900574|journal=Journal of Personality Assessment|volume=74|issue=3|pages=489–503|doi=10.1207/S15327752JPA7403_11|issn=0022-3891|pmid=10900574}}</ref>Screening Measure (Primary Reference) ! AUC ! DiLR+ (Score) ! DiLR- (Score) !Clinical Generalizability !Where to access |- |Serum leptin level<ref name=":7">{{Cite journal|last=Föcker|first=M.|last2=Timmesfeld|first2=N.|last3=Scherag|first3=S.|last4=Bühren|first4=K.|last5=Langkamp|first5=M.|last6=Dempfle|first6=A.|last7=Sheridan|first7=E. M.|last8=Zwaan|first8=M. de|last9=Fleischhaker|first9=C.|date=2011-04-01|title=Screening for anorexia nervosa via measurement of serum leptin levels|url=https://link.springer.com/article/10.1007/s00702-010-0551-z|journal=Journal of Neural Transmission|language=en|volume=118|issue=4|pages=571–578|doi=10.1007/s00702-010-0551-z|issn=0300-9564}}</ref> |0.984 (N=139) |14.72 (<2.31) |0.10 (2.31+) |Adolescent and adult patients in the acute phase of AN according to the DSM-IV and no AN pretreatment versus healthy lean female volunteer university students. |None |- |Body Mass Index (BMI)<ref name=":7" /> |0.936 (N=139) |5.89 (<17.10) |0.11 (17.10+) |Adolescent and adult patients in the acute phase of AN according to the DSM-IV and no AN pretreatment versus healthy lean female volunteer university students. |None |- |EAT-26&nbsp;<ref name=":4" /><ref>{{Cite journal|title = The eating attitudes test: psychometric features and clinical correlates|url = http://www.ncbi.nlm.nih.gov/pubmed/6961471|journal = Psychological Medicine|date = 1982-11-01|issn = 0033-2917|pmid = 6961471|pages = 871–878|volume = 12|issue = 4|first = D. M.|last = Garner|first2 = M. P.|last2 = Olmsted|first3 = Y.|last3 = Bohr|first4 = P. E.|last4 = Garfinkel}}</ref> |.90 (N=129) |12.83 (20+) |.24 (<20) |Low-moderate: College women with no eating disorder versus college women with a DSM-IV eating disorder. Eating disorders were not separated. |[https://www.eat-26.com/eat-26/ Adult Version PDF][http://www.1000livesplus.wales.nhs.uk/sitesplus/documents/1011/ChEAT.pdf Child Version PDF] |- |EDE-Q&nbsp;<ref name=":1">{{Cite journal|title = Assessment of eating disorders: interview or self-report questionnaire?|url = http://www.ncbi.nlm.nih.gov/pubmed/7866415|journal = The International Journal of Eating Disorders|date = 1994-12-01|issn = 0276-3478|pmid = 7866415|pages = 363–370|volume = 16|issue = 4|first = C. G.|last = Fairburn|first2 = S. J.|last2 = Beglin}}</ref> |.96 &nbsp;<ref name=":1" />(N=1170) | 6.57 (2.3+)<ref name=":5">{{Cite journal|last=Fairburn|first=C. G.|last2=Beglin|first2=S. J.|date=December 1994|title=Assessment of eating disorders: interview or self-report questionnaire?|url=https://www.ncbi.nlm.nih.gov/pubmed/7866415|journal=The International Journal of Eating Disorders|volume=16|issue=4|pages=363–370|issn=0276-3478|pmid=7866415}}</ref> | 0.09 (<2.3)<ref name=":5" /> |Moderate: Dutch treatment-seeking females meeting DSM-IV criteria for an eating disorder versus female adult general population sample recruited through advertisements and personal contacts. Eating disorders were not separated.&nbsp;<ref name=":1" /> Moderate: “Clinically significant eating disorder” from a community sample versus female adults individuals without “clinically significant eating disorder” from same sample. Eating disorders were not separated.<ref name=":5" /> |[http://www.corc.uk.net/media/1273/ede-q_quesionnaire.pdf PDF] |} === Interpreting anorexia nervosa screening measure scores === * For information on interpreting screening measure scores, click [[Evidence based assessment/Prediction phase#Interpreting screening measure scores|here.]] * Also see the page on [https://en.wikipedia.org/wiki/Likelihood_ratios_in_diagnostic_testing likelihood ratios in diagnostic testing] for more information. ==[[Evidence based assessment/Prescription phase|'''Prescription phase''']]== ===Gold standard diagnostic interviews=== * For a list of broad reaching diagnostic interviews sortable by disorder with PDFs (if applicable), [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prescription_phase&wteswitched=1#Common_Diagnostic_Interviews click here.] ===Recommended diagnostic interviews for anorexia nervosa=== {| class="wikitable sortable" border="1" ! colspan="5" |Diagnostic instruments for anorexia nervosa |- ! Measure ! Format (Reporter) ! Age Range ! Administration/ Completion Time !Where to access |- |[https://www.credo-oxford.com/7.2.html Eating Disorder Examination (EDE)] <ref>{{Cite book|url=https://www.worldcat.org/oclc/1160972551|title=Assessment of disorders in childhood and adolescence|date=2020|others=Eric Arden Youngstrom, Mitchell J. Prinstein, Eric J. Mash, Russell A. Barkley|isbn=978-1-4625-4365-6|edition=Fifth edition|location=New York|oclc=1160972551}}</ref> <ref>{{Cite book|url=https://www.worldcat.org/oclc/314222270|title=A guide to assessments that work|date=2008|publisher=Oxford University Press|others=John Hunsley, Eric J. Mash|isbn=0-19-804245-0|location=New York|oclc=314222270}}</ref> |Semistructured (child and adult) |8-16 (child version) 16+ (adult version) |45-75 minutes |[https://www.phenxtoolkit.org/protocols/view/230101 Child version PDF][https://www.credo-oxford.com/7.2.html Adult version PDF][https://osf.io/eytc5 PDF] |- |Structured Clinical Interview for DSM-5-Clinician Version (SCID-5-CV)<ref>{{Cite journal|last=Shabani|first=Amir|last2=Masoumian|first2=Samira|last3=Zamirinejad|first3=Somayeh|last4=Hejri|first4=Maryam|last5=Pirmorad|first5=Tahereh|last6=Yaghmaeezadeh|first6=Hooman|date=2021-05|title=Psychometric properties of Structured Clinical Interview for DSM‐5 Disorders‐Clinician Version (SCID‐5‐CV)|url=https://onlinelibrary.wiley.com/doi/10.1002/brb3.1894|journal=Brain and Behavior|language=en|volume=11|issue=5|doi=10.1002/brb3.1894|issn=2162-3279|pmc=PMC8119811|pmid=33729681}}</ref> |Structured Interview (Adult ) |16+ |Varies |[https://www.columbiapsychiatry.org/research/research-labs/diagnostic-and-assessment-lab/structured-clinical-interview-dsm-disorders-11 Website to purchase] |- | [https://dawba.info/a0.html Development and Well-Being Assessment (DAWBA)] <ref>{{Cite book|url=https://www.worldcat.org/oclc/1160972551|title=Assessment of disorders in childhood and adolescence|date=2020|others=Eric Arden Youngstrom, Mitchell J. Prinstein, Eric J. Mash, Russell A. Barkley|isbn=978-1-4625-4365-6|edition=Fifth edition|location=New York|oclc=1160972551}}</ref> | Structured (child/adolescent and parent) | 11-18 |10-20 minutes for the eating disorder module |[https://osf.io/zpbna/?view_only=245bef061d284c17ab9dedad5a59e1b8 English PDF] [https://dawba.info/py/dawbainfo/b1.py Additional languages] |} '''Note:''' '''L''' = Less than adequate; '''A''' = Adequate; '''G''' = Good; '''E''' = Excellent; '''U''' = Unavailable; '''NA''' = Not applicable ==[[Evidence based assessment/Process phase|'''Process phase''']]== The following section contains a brief overview of treatment options for anorexia nervosa and a list of process and outcome measures for anorexia nervosa. The section includes benchmarks based on published norms for several outcome and severity measures, as well as information about commonly used process measures. Process and outcome measures are used as part of the [[Evidence based assessment/Process phase|process phase]] of assessment. For more information on the differences between process and outcome measures, see the page on the [[Evidence based assessment/Process phase|process phase of assessment]]. ===Process measures=== Body weight is commonly monitored by clinicians throughout the AN treatment process as helping individuals regain and maintain a healthy weight is a primary treatment goal for AN. Many treatment centers have policies prohibiting patients from seeing their weight. Motivational Stages of Change may be used to monitor individuals’ readiness to take action against eating disorder behaviors. It has demonstrated predictive validity in a sample of female adolescents attending eating disorder treatment groups.<ref>{{Cite journal|last=Gusella|first=Joanne|last2=Butler|first2=Gordon|last3=Nichols|first3=Laura|last4=Bird|first4=Debbie|date=2003-01-01|title=A brief questionnaire to assess readiness to change in adolescents with eating disorders: its applications to group therapy|url=http://onlinelibrary.wiley.com/doi/10.1002/erv.481/abstract|journal=European Eating Disorders Review|language=en|volume=11|issue=1|pages=58–71|doi=10.1002/erv.481|issn=1099-0968}}</ref> See Appendix E. === Outcome and severity measures === This table includes clinically significant benchmarks for anorexia nervosa specific outcome measures * Information on how to interpret this table can be [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Process_phase found here]. * Additionally, these [[Evidence based assessment/Vignettes|vignettes]] might be helpful resources for understanding appropriate adaptation of outcome measures in practice. *''<u>For clinically significant change benchmarks for the CBCL, YSR, and TRF total, externalizing, internalizing, and attention benchmarks,</u>'' [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Process_phase&wteswitched=1#Clinically_significant_change_benchmarks_for_widely-used_outcome_measures see here.] {| class="wikitable sortable" border="1" | colspan="8" |'''Clinically significant change benchmarks with common instruments for anorexia nervosa''' |- | colspan="8" span style="font-size:110%; text-align:center;" | <b> Benchmarks Based on Published Norms</b> |- | rowspan="2" style="text-align:center;font-size:130%;" |<b> Measure</b> | rowspan="2" style="text-align:center;font-size:130%;" | <b> Subscale</b> | colspan="3" style="text-align:center;font-size:130%" width="300" | <b> Cut-off scores</b> | colspan="3" style="text-align:center;font-size:120%" | <b> Critical Change <br> (unstandardized scores)</b> |- | style="text-align:center;font-size:110%" |<b> A</b> | style="text-align:center;font-size:110%" |<b> B</b> | style="text-align:center;font-size:110%" |<b> C</b> | style="text-align:center;font-size:110%" |<b> 95%</b> | style="text-align:center;font-size:110%" |<b> 90%</b> | style="text-align:center;font-size:110%" |<b> SE_difference</b> |- | rowspan="5" style="text-align:center;" |'''EDE-Q <ref name=":2">{{Cite journal|last=Mond|first=J. M.|last2=Hay|first2=P. J.|last3=Rodgers|first3=B.|last4=Owen|first4=C.|last5=Beumont|first5=P. J. V.|date=May 2004|title=Validity of the Eating Disorder Examination Questionnaire (EDE-Q) in screening for eating disorders in community samples|url=https://www.ncbi.nlm.nih.gov/pubmed/15033501|journal=Behaviour Research and Therapy|volume=42|issue=5|pages=551–567|doi=10.1016/S0005-7967(03)00161-X|issn=0005-7967|pmid=15033501}}</ref>''' | style="text-align:right;" |''Global'' |1.4 |3.2 |2.3 |.7 |.6 |.3 |- | style="text-align:right;" |''Restraint'' |(-.3) |3.6 |1.8 |1.5 |1.2 |.8 |- | style="text-align:right;" |''Eating Concern'' |.1 |2.0 |1.2 |1.1 |.9 |.6 |- | style="text-align:right;" |''Weight Concern'' |1.5 |3.9 |2.6 |1.0 |.9 |.5 |- | style="text-align:right;" |''Shape Concern'' |2.1 |4.8 |3.2 |.9 |.7 |.4 |- | rowspan="5" style="text-align:center;" |'''EDE <ref name=":2" />''' | style="text-align:right;" |''Global'' |1.7 |2.3 |1.9 |1.9 |1.6 |1.0 |- | style="text-align:right;" |''Restraint'' |.3 |3.3 |1.9 |1.8 |1.5 |.9 |- | style="text-align:right;" |''Eating Concern'' |(-.5) |.9 |.5 |.8 |.7 |.4 |- | style="text-align:right;" |''Weight Concern'' |2.0 |2.8 |2.4 |1.3 |1.1 |.7 |- | style="text-align:right;" |''Shape Concern'' |2.0 |3.2 |2.6 |1.2 |1.0 |.6 |- | rowspan="1" style="text-align:center;" |'''EAT-26 <ref name=":0">{{Cite journal|last=Mintz|first=L. B.|last2=O'Halloran|first2=M. S.|date=2000-06-01|title=The Eating Attitudes Test: validation with DSM-IV eating disorder criteria|url=http://www.ncbi.nlm.nih.gov/pubmed/10900574|journal=Journal of Personality Assessment|volume=74|issue=3|pages=489–503|doi=10.1207/S15327752JPA7403_11|issn=0022-3891|pmid=10900574}}</ref>''' | style="text-align:right;" |''Total'' |6.5 |19.6 |15.0 |7.9 |6.7 |4.0 |} '''Note:''' “A” = Away from the clinical range, “B” = Back into the nonclinical range, “C” = Closer to the nonclinical than clinical mean. '''Search terms:''' [Anorexia Nervosa OR eating disorder] AND [validity OR clinical significance] in Google Scholar === Treatment === {{collapse top| Click here for more information on treatment for AN}} * Treatment of AN typically consists of restoring the individual to a healthy weight and addressing thoughts and behaviors which are related to the eating disorder. It may involve re-nutrition, psychotherapy, nutritional counseling, and medication. * Literature reviews of existing research indicate that evidence supporting AN treatment is lacking. A systematic review of AN treatment efficacy studies by Bulik<ref>{{Cite journal|title = Anorexia nervosa treatment: a systematic review of randomized controlled trials|url = http://www.ncbi.nlm.nih.gov/pubmed/17370290|journal = The International Journal of Eating Disorders|date = 2007-05-01|issn = 0276-3478|pmid = 17370290|pages = 310–320|volume = 40|issue = 4|doi = 10.1002/eat.20367|first = Cynthia M.|last = Bulik|first2 = Nancy D.|last2 = Berkman|first3 = Kimberly A.|last3 = Brownley|first4 = Jan A.|last4 = Sedway|first5 = Kathleen N.|last5 = Lohr}}</ref> found that evidence supporting medications, medications and behavioral interventions, and behavioral interventions alone in adults is weak. * There is moderately strong evidence suggesting that behavioral interventions may be helpful for adolescents. In particular, adolescents may benefit from family therapy. * Clinical trials investigating AN treatment suffer from high rates of attrition, as key features of AN (e.g., denial, fear of weight gain) may contribute to low motivation for remaining in treatment. * More severe cases of AN may be treated in inpatient settings, which are equipped to manage the re-nutrition process and provide medical monitoring. * Partial hospitalization and intensive outpatient programs may provide intermediate levels of treatment intensity to assist individuals in the transition from intensive care to outpatient care after weight restoration. {{collapse bottom}} * Please refer to the page on [https://en.wikipedia.org/wiki/Anorexia_nervosa anorexia nervosa] for more information on available treatment or go to [http://effectivechildtherapy.org/concerns-symptoms-disorders/disorders/eating-body-image-problems/ the Effective Child Therapy page for Eating & Body Image Problems] for a curated resource on effective treatments for anorexia nervosa. == '''External resources''' == # [http://apps.who.int/classifications/icd10/browse/2010/en#/F50.0 ICD-10 diagnostic criteria] # [https://en.wikiversity.org/w/index.php?title=Helping_Give_Away_Psychological_Science/Resources/Annotated_List_of_Where_and_How_to_Find_a_Therapist&wteswitched=1#Other_low-cost_options Find-a-Therapist] ##This is a curated list of find-a-therapist websites where you can find a provider # NIMH: [https://www.nimh.nih.gov/health/publications/eating-disorders/index.shtml ''Eating Disorders--About More Than Food''] and [https://www.nimh.nih.gov/health/topics/eating-disorders/index.shtml ''Eating Disorders''] ##These NIMH website posts provide more information on anorexia nervosa #[https://www.hopkinsmedicine.org/psychiatry/specialty_areas/eating_disorders/ John's Hopkins Resource] (guide about anorexia nervosa, treatment, and more) # OMIM (Online Mendelian Inheritance in Man) ##[https://www.omim.org/entry/606788?search=anorexia%20nervosa&highlight=nervosa%20anorexia Anorexia nervosa] #[http://effectivechildtherapy.org/concerns-symptoms-disorders/disorders/eating-body-image-problems/ Effective Child Therapy page for anorexia nervosa] ##Effective Child Therapy is website sponsored by Division 53 of the American Psychological Association (APA), or The [https://sccap53.org Society of Clinical Child and Adolescent Psychology] (SCCAP), in collaboration with the Association for Behavioral and Cognitive Therapies (ABCT). Use for information on symptoms and available treatments. == '''References''' == {{collapse top|Click here for references}} {{Reflist|30em}} [[Category:Psychological disorder portfolios|{{SUBPAGENAME}}]] {{collapse bottom}} nsxhbvdt2wc5gasge9xrzeyfmlhdex4 2413986 2413985 2022-08-12T15:45:05Z Aherman012 2943941 /* Prediction phase */ wikitext text/x-wiki <noinclude>{{Helping Give Away Psychological Science Banner}}</noinclude> {{medical disclaimer}} {{:{{BASEPAGENAME}}/Sidebar}} ==[[Evidence based assessment/Portfolio template/What is a "portfolio"|'''What is a "portfolio"?''']]== For background information on what assessment portfolios are, click the link in the heading above. Want even 'more' information about this topic? There's an extended version of this page [[Evidence-based assessment/Anorexia nervosa (assessment portfolio)/extended version|here]]. == [[Evidence based assessment/Preparation phase|'''Preparation phase''']] == === Diagnostic criteria for anorexia nervosa === {{blockquotetop}} '''ICD-11 Criteria''' Anorexia Nervosa is characterized by significantly low body weight, which is less than minimal normal/expected weight for the individual’s height, sex, age and developmental stage (body mass index (BMI) less than 18.5 kg/m2 in adults and BMI-for-age under fifth percentile in children and adolescents) that is not due to another health condition or to the unavailability of food. Low body weight is accompanied by a persistent pattern of behaviors to prevent restoration of normal weight, which may include behaviors aimed at reducing energy intake (restricted eating), purging behaviors (e.g., self-induced vomiting, misuse of laxatives), and behaviors aimed at increasing energy expenditure (e.g., excessive exercise), typically associated with a fear of weight gain. Low body weight or shape is central to the person's self-evaluation or is inaccurately perceived to be normal or even excessive. '''Changes in DSM-5''' * The diagnostic criteria for anorexia nervosa changed slightly from [[DSM-IV]] to [[w:Diagnostic_and_Statistical_Manual_of_Mental_Disorders#DSM-IV-TR_.282000.29|DSM-5]]. Summaries are available [http://www.dsm5.org/Documents/changes%20from%20dsm-iv-tr%20to%20dsm-5.pdf here] and [[w:DSM-5|here]]. {{blockquotebottom}} === Base rates of anorexia nervosa in different populations and clinical settings === This section describes the demographic setting of the population(s) sampled, base rates of diagnosis such as prevalence rates, country/region sampled, and the diagnostic method that was used. Using this information, clinicians will be able to anchor the rate of adolescent depression that they are likely to see in their clinical practice. * '''''To see prevalence rates across multiple disorders,''''' [[Evidence based assessment/Preparation phase#Base rates for transdiagnostic comparison|'''''click here.''''']] {| class="wikitable sortable" |- ! Demography ! Setting (Reference) ! Base Rate ! Diagnostic Method |- |Nationally representative US sample of adults |Non-clinical: Population-based (NCS-R)<ref>Hudson, James I.; Hiripi, Eva; Pope, Harrison G.; Kessler, Ronald C. (2007-02-01). "The prevalence and correlates of eating disorders in the National Comorbidity Survey Replication".''Biological Psychiatry'' '''61''' (3): 348–358. doi:10.1016/j.biopsych.2006.03.040. ISSN 0006-3223. PMC 1892232. <nowiki>PMID 16815322</nowiki></ref> |.9% Female, .3% Male |World Health Organization-Clinical International Diagnostic Interview (WHO-CIDI) |- |Nationally representative US sample of adolescents |Non-clinical: Population-based (NCS-A)<ref>Swanson, Sonja A.; Crow, Scott J.; Le Grange, Daniel; Swendsen, Joel; Merikangas, Kathleen R. (2011-07-01). "Prevalence and correlates of eating disorders in adolescents. Results from the national comorbidity survey replication adolescent supplement". ''Archives of General Psychiatry'' '''68''' (7): 714–723. doi:10.1001/archgenpsychiatry.2011.22. ISSN 1538-3636.<nowiki>PMID 21383252</nowiki></ref> |.3% Female, .3% Male |WHO-CIDI |- |Nationally representative US sample of 9- and 10-year old children |Non-clinical: US Population-based prevalence (Adolescent Brain Cognitive Development (ABCD) study<ref>{{Cite journal|last=Rozzell|first=Kaitlin|last2=Moon|first2=Da Yeoun|last3=Klimek|first3=Patrycja|last4=Brown|first4=Tiffany|last5=Blashill|first5=Aaron J.|date=2019-01-01|title=Prevalence of Eating Disorders Among US Children Aged 9 to 10 Years: Data From the Adolescent Brain Cognitive Development (ABCD) Study|url=http://archpedi.jamanetwork.com/article.aspx?doi=10.1001/jamapediatrics.2018.3678|journal=JAMA Pediatrics|language=en|volume=173|issue=1|pages=100|doi=10.1001/jamapediatrics.2018.3678|issn=2168-6203|pmc=PMC6583451|pmid=30476983}}</ref> |0.1%, no gender differences |DSM-5 using Kiddie Schedule for Affective Disorders and Schizophrenia (KSADS) |- |Latino Households in the US |Non-clinical: Latinos in US<ref>Alegria, Margarita; Woo, Meghan; Cao, Zhun; Torres, Maria; Meng, Xiao-li; Striegel-Moore, Ruth (2007-11-01). "Prevalence and correlates of eating disorders in Latinos in the United States".''The International Journal of Eating Disorders''. 40 Suppl: S15–21. doi:10.1002/eat.20406. ISSN 0276-3478. PMC 2680162. <nowiki>PMID 17584870</nowiki></ref> |.12% Female, .03% Male |WHO-CIDI |- |National probability sample of adult and adolescent African Americans and Caribbean Black people |Non-clinical: African Americans and Caribbean Black people in the US (NSAL)<ref>Taylor, Jacquelyn Y.; Caldwell, Cleopatra Howard; Baser, Raymond E.; Faison, Nakesha; Jackson, James S. (2007-11-01). "Prevalence of eating disorders among Blacks in the National Survey of American Life". ''The International Journal of Eating Disorders''. 40 Suppl: S10–14. doi:10.1002/eat.20451. ISSN 0276-3478. PMC 2882704. <nowiki>PMID 17879287</nowiki></ref> |.14% Female, .2% Male |WHO-CIDI |- |Asian American adults in US households |Non-clinical: National Latino and Asian American Study (NLAAS) |.12% Female, .05% Male |WHO-CIDI |- | US African American college females | Non-clinical; college students<ref>Tyler ID. A true picture of eating disorders among African American women: a review of literature. ABNF J. 2003;14(3):73-4.</ref> || .0% || Eating Disorder Diagnostic Questionnaire (EDD-Q) |- | US Female Adolescents | Non-clinical; Adolescents<ref>Stice, E., Becker, C. B., & Yokum, S. (2013). Eating disorder prevention: Current evidence-base and future directions. ''Int. J. Eat. Disord. International Journal of Eating Disorders,'' ''46''(5), 478-485.</ref> || .8% || Eating Disorder Diagnosis Interview (EDDI) |- | US Division-I Varsity Student Athletes | Non-clinical; student-athletes<ref>Johnson C, Powers PS, Dick R. Athletes and eating disorders: the national collegiate athletic association study. Int J Eat Disord 1999;26:179e88.</ref> || .0% || Eating Disorder Inventory-2 (EDI-2) |- | Active duty females in US Army, Navy, Airforce, and Marines | Non-clinical; Military<ref>McNulty, PAF. (2001). Prevalence and contributing factors of eating disorder behaviors in active duty service women in the Army, Navy, Air Force and Marines. Military Medicine, 166(1), 53-58. </ref> || 1.1% || EDI-2 |- |US Caucasian female same-sex twins |Non-clinical; Commonwealth of Virginia Mid-Atlantic Twin Registry (MATR)<ref>Kendler KS, Walters EE, Neale MC, Kessler R, Heath A, Eaves L. The structure of genetic and environmental risk factors for six major psychiatric disorders in women. Archives of general psychiatry. 1995;52:374–383.</ref> |1.62% (narrow), 3.70% (broad) |Structured Clinical Interview for DSM Disorders (SCID) |- |South Australian older adolescents and adults |Non-clinical; Health Omnibus Survey (HOS) |.46% (3 months; combined) |Eating Disorder Examination (EDE) |- |US Military |Military<ref>{{Cite journal|title=Diagnosed eating disorders in the U.S. Military: a nine year review|url=http://www.ncbi.nlm.nih.gov/pubmed/18821361|journal=Eating Disorders|date=2008-12-01|issn=1532-530X|pmid=18821361|pages=363–377|volume=16|issue=5|doi=10.1080/10640260802370523|first=Amanda J.|last=Antczak|first2=Teresa L.|last2=Brininger}}</ref> |.04% (combined) |ICD codes from electronic records |- |US Military Academy cadets |Non-clinical; Military |.02% (7 years) Female, 0.0% (7 years) Males |[https://www.eat-26.com/ Eating Attitudes Test- 26 items] (EAT-26)<ref>{{Cite web|url=https://www.eat-26.com/|title=EAT-26: Eating Attitudes Test & Eating Disorder Testing – Use the EAT-26 to help you determine if you need to speak to a mental health professional to get help for an eating disorder.|last=admin|language=en|access-date=2022-05-30}}</ref> |- |US Navy female nurses |Non-clinical; Military |1.1% (current & past) Female |DSM-III |- |US veterans |Non-clinical; Military |.04% Female, .005% Males |ICD-9-CM |- |Active duty males in US Navy |Non-clinical; Military |2.5% Males |N/A |- |US alcohol-dependent adults from San Diego, St. Lois, Iowa City, Farmington, New York, & Indianapolis |Clinical; Collaborative Study on the Genetics of Alcoholism (COGA)<ref>{{Cite journal|title=Anorexia nervosa and bulimia nervosa in alcohol-dependent men and women and their relatives|url=http://www.ncbi.nlm.nih.gov/pubmed/8540597|journal=The American Journal of Psychiatry|date=1996-01-01|issn=0002-953X|pmid=8540597|pages=74–82|volume=153|issue=1|doi=10.1176/ajp.153.1.74|first=M. A.|last=Schuckit|first2=J. E.|last2=Tipp|first3=R. M.|last3=Anthenelli|first4=K. K.|last4=Bucholz|first5=V. M.|last5=Hesselbrock|first6=J. I.|last6=Nurnberger}}</ref> |1.41% (lifetime) Female, .00% (lifetime) Male |SSAGA |- |Healthcare provider records |Non-clinical; healthcare members |.0269% (current) | |- |US high school students in west central Oregon |Non-clinical; high school students |. 00% (point), .45% (lifetime) Female .00% (point), .00% (lifetime) Males |DSM-III-R₄ |- |Canadian treatment-seeking substance users |Clinical; substance users |.4% (lifetime), .3% (current) Female .4% (lifetime), .3% (current) Males |DIS₉ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''Europe''' |- |Adolescent females residing in Navarra, Spain |Non-clinical; adolescents |.3% Female |EAT-40₃ |- |Adolescents in secondary schools in Sør-Trøndelag, County in Norway |Non-clinical; adolescents |.7% (lifetime) Female, .2% Male |SEDs₁₀ |- |Adolescents in a comprehensive school in Ostrobothnia district in Finland |Non-clinical; adolescents |.7% (point; age 15), 1.8% (lifetime, age 15), .00% (point, age 18), 2.6% (lifetime, age 18), .9% (3 years) Female .00% (point & lifetime) Males |RAB-T₁₁&nbsp;& RAB-R₁₂ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''Australia''' |- |Adolescent females residing in Victoria, Australia |Non-clinical; adolescents |.00% (full), 1.8% (partial) Female |BET₁₃ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''Central & South America''' |- |Mexican first & second year college females |Non-clinical; college students |.00% Female |EAT-40₃ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''East Asia''' |- |Adolescent and adult Japanese patients at a university hospital |Clinical; eating disorder patients |.53% Female |DSM-III-R₄ |- |Korean adults |Non-clinical; Korean Epidemiologic Catchment Area (KECA) Study |.1% (lifetime), .1% (12 months) Female .2% (lifetime), .00% (12 months) Males |K-CIDI₁₅&nbsp;2.1 |- |Alcohol-dependent adults |Centers participating in the Collaborative Study on the Genetics of Alcoholism in San Diego; St. Louis; Iowa City; Farmington, CN; New York; & Indianapolis |1.41% Females |Semi-Structured Assessment for the Genetics of Alcoholism; criteria based on DSM-III-R |} ==[[Evidence based assessment/Prediction phase|'''Prediction phase''']]== === Psychometric properties of screening instruments for anorexia nervosa === The following section contains a list of screening and diagnostic instruments for anorexia nervosa. The section includes administration information, psychometric data, and PDFs or links to the screenings. * Screenings are used as part of the [[Evidence based assessment/Prediction phase|prediction phase]] of assessment; for more information on interpretation of this data, or how screenings fit in to the assessment process, click [[Evidence based assessment/Prediction phase|here.]] * ''For a list of more broadly reaching screening instruments, [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prediction_phase&wteswitched=1#Psychometric_properties_of_common_screening_instruments '''click here.''']'' {| class="wikitable" |- ! Measure !Format (Reporter) !Age Range !Administration/ Completion Time !Where to Access |- |[[wikipedia:Eating_Disorder_Examination_Interview|Eating Disorder Examination Questionnaire (EDE-Q)]] |Questionnaire (Patient) |14+ |15-20 min | [http://www.corc.uk.net/media/1273/ede-q_quesionnaire.pdf PDF] |- |[[wikipedia:Eating_Disorder_Diagnostic_Scale|EDDS (Eating Disorder Diagnosis Scale)]]<ref>{{Cite journal|last=Stice|first=Eric|last2=Telch|first2=Christy F.|last3=Rizvi|first3=Shireen L.|date=2000|title=Development and validation of the Eating Disorder Diagnostic Scale: A brief self-report measure of anorexia, bulimia, and binge-eating disorder.|url=http://doi.apa.org/getdoi.cfm?doi=10.1037/1040-3590.12.2.123|journal=Psychological Assessment|language=en|volume=12|issue=2|pages=123–131|doi=10.1037/1040-3590.12.2.123|issn=1939-134X}}</ref> |Questionnaire (Patient) |13 - 65 |10-15 min | [http://www.ori.org/files/Static%20Page%20Files/EDDSDSM-5_10_14.pdf PDF] |- |Eating Attitudes Test- 26(EAT-26; Adult version)<ref>{{Cite journal|last=Garner|first=David M.|last2=Garfinkel|first2=Paul E.|date=1979-05|title=The Eating Attitudes Test: an index of the symptoms of anorexia nervosa|url=http://dx.doi.org/10.1017/s0033291700030762|journal=Psychological Medicine|volume=9|issue=2|pages=273–279|doi=10.1017/s0033291700030762|issn=0033-2917}}</ref> Child Eating Attitudes Test - 26 (ChEAT-26; child version)<ref>{{Cite journal|last=Almeida|first=M.C.|last2=Carvalho|first2=D.L.D.B.|last3=Rigolino|first3=R.|date=2012-07|title=Reliability of a Brazilian version of children's eating attitude test|url=http://dx.doi.org/10.1016/j.neurenf.2012.04.196|journal=Neuropsychiatrie de l'Enfance et de l'Adolescence|volume=60|issue=5|pages=S158|doi=10.1016/j.neurenf.2012.04.196|issn=0222-9617}}</ref> |Questionnaire (Patient) |13+ (adult version) 8 -13 (child version) |5-10 min |PDFs * [https://www.eat-26.com/eat-26/ Adult Version PDF] * [http://www.1000livesplus.wales.nhs.uk/sitesplus/documents/1011/ChEAT.pdf Child Version PDF] |} <ref>Hunsley, J., & Mash, E. J. (2008). Guide to Assessments that Work. Cary, NC, USA: Oxford University Press, USA. Retrieved from <nowiki>http://www.ebrary.com</nowiki></ref>'''Note:''' '''L''' = Less than adequate; '''A''' = Adequate; '''G''' = Good; '''E''' = Excellent; '''U''' = Unavailable; '''NA''' = Not applicable ===Likelihood ratios and AUCs of screening instruments for anorexia nervosa=== * ''For a list of the likelihood ratios for more broadly reaching screening instruments, [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prediction_phase&wteswitched=1#Likelihood_ratios_and_AUCs_of_common_screening_instruments '''click here.''']'' {| class="wikitable sortable" border="1" |- ! <ref name=":4">{{Cite journal|last=Mintz|first=L. B.|last2=O'Halloran|first2=M. S.|date=June 2000|title=The Eating Attitudes Test: validation with DSM-IV eating disorder criteria|url=https://www.ncbi.nlm.nih.gov/pubmed/10900574|journal=Journal of Personality Assessment|volume=74|issue=3|pages=489–503|doi=10.1207/S15327752JPA7403_11|issn=0022-3891|pmid=10900574}}</ref>Screening Measure (Primary Reference) ! AUC ! DiLR+ (Score) ! DiLR- (Score) !Clinical Generalizability !Where to access |- |Serum leptin level<ref name=":7">{{Cite journal|last=Föcker|first=M.|last2=Timmesfeld|first2=N.|last3=Scherag|first3=S.|last4=Bühren|first4=K.|last5=Langkamp|first5=M.|last6=Dempfle|first6=A.|last7=Sheridan|first7=E. M.|last8=Zwaan|first8=M. de|last9=Fleischhaker|first9=C.|date=2011-04-01|title=Screening for anorexia nervosa via measurement of serum leptin levels|url=https://link.springer.com/article/10.1007/s00702-010-0551-z|journal=Journal of Neural Transmission|language=en|volume=118|issue=4|pages=571–578|doi=10.1007/s00702-010-0551-z|issn=0300-9564}}</ref> |0.984 (N=139) |14.72 (<2.31) |0.10 (2.31+) |Adolescent and adult patients in the acute phase of AN according to the DSM-IV and no AN pretreatment versus healthy lean female volunteer university students. |None |- |Body Mass Index (BMI)<ref name=":7" /> |0.936 (N=139) |5.89 (<17.10) |0.11 (17.10+) |Adolescent and adult patients in the acute phase of AN according to the DSM-IV and no AN pretreatment versus healthy lean female volunteer university students. |None |- |EAT-26&nbsp;<ref name=":4" /><ref>{{Cite journal|title = The eating attitudes test: psychometric features and clinical correlates|url = http://www.ncbi.nlm.nih.gov/pubmed/6961471|journal = Psychological Medicine|date = 1982-11-01|issn = 0033-2917|pmid = 6961471|pages = 871–878|volume = 12|issue = 4|first = D. M.|last = Garner|first2 = M. P.|last2 = Olmsted|first3 = Y.|last3 = Bohr|first4 = P. E.|last4 = Garfinkel}}</ref> |.90 (N=129) |12.83 (20+) |.24 (<20) |Low-moderate: College women with no eating disorder versus college women with a DSM-IV eating disorder. Eating disorders were not separated. |PDFs * [https://www.eat-26.com/eat-26/ Adult Version PDF] * [http://www.1000livesplus.wales.nhs.uk/sitesplus/documents/1011/ChEAT.pdf Child Version PDF] |- |EDE-Q&nbsp;<ref name=":1">{{Cite journal|title = Assessment of eating disorders: interview or self-report questionnaire?|url = http://www.ncbi.nlm.nih.gov/pubmed/7866415|journal = The International Journal of Eating Disorders|date = 1994-12-01|issn = 0276-3478|pmid = 7866415|pages = 363–370|volume = 16|issue = 4|first = C. G.|last = Fairburn|first2 = S. J.|last2 = Beglin}}</ref> |.96 &nbsp;<ref name=":1" />(N=1170) | 6.57 (2.3+)<ref name=":5">{{Cite journal|last=Fairburn|first=C. G.|last2=Beglin|first2=S. J.|date=December 1994|title=Assessment of eating disorders: interview or self-report questionnaire?|url=https://www.ncbi.nlm.nih.gov/pubmed/7866415|journal=The International Journal of Eating Disorders|volume=16|issue=4|pages=363–370|issn=0276-3478|pmid=7866415}}</ref> | 0.09 (<2.3)<ref name=":5" /> |Moderate: Dutch treatment-seeking females meeting DSM-IV criteria for an eating disorder versus female adult general population sample recruited through advertisements and personal contacts. Eating disorders were not separated.&nbsp;<ref name=":1" /> Moderate: “Clinically significant eating disorder” from a community sample versus female adults individuals without “clinically significant eating disorder” from same sample. Eating disorders were not separated.<ref name=":5" /> |[http://www.corc.uk.net/media/1273/ede-q_quesionnaire.pdf PDF] |} === Interpreting anorexia nervosa screening measure scores === * For information on interpreting screening measure scores, click [[Evidence based assessment/Prediction phase#Interpreting screening measure scores|here.]] * Also see the page on [https://en.wikipedia.org/wiki/Likelihood_ratios_in_diagnostic_testing likelihood ratios in diagnostic testing] for more information. ==[[Evidence based assessment/Prescription phase|'''Prescription phase''']]== ===Gold standard diagnostic interviews=== * For a list of broad reaching diagnostic interviews sortable by disorder with PDFs (if applicable), [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prescription_phase&wteswitched=1#Common_Diagnostic_Interviews click here.] ===Recommended diagnostic interviews for anorexia nervosa=== {| class="wikitable sortable" border="1" ! colspan="5" |Diagnostic instruments for anorexia nervosa |- ! Measure ! Format (Reporter) ! Age Range ! Administration/ Completion Time !Where to access |- |[https://www.credo-oxford.com/7.2.html Eating Disorder Examination (EDE)] <ref>{{Cite book|url=https://www.worldcat.org/oclc/1160972551|title=Assessment of disorders in childhood and adolescence|date=2020|others=Eric Arden Youngstrom, Mitchell J. Prinstein, Eric J. Mash, Russell A. Barkley|isbn=978-1-4625-4365-6|edition=Fifth edition|location=New York|oclc=1160972551}}</ref> <ref>{{Cite book|url=https://www.worldcat.org/oclc/314222270|title=A guide to assessments that work|date=2008|publisher=Oxford University Press|others=John Hunsley, Eric J. Mash|isbn=0-19-804245-0|location=New York|oclc=314222270}}</ref> |Semistructured (child and adult) |8-16 (child version) 16+ (adult version) |45-75 minutes |PDFs * [https://www.phenxtoolkit.org/protocols/view/230101 Child version PDF] * [https://www.credo-oxford.com/7.2.html Adult version PDF] |- |Structured Clinical Interview for DSM-5-Clinician Version (SCID-5-CV)<ref>{{Cite journal|last=Shabani|first=Amir|last2=Masoumian|first2=Samira|last3=Zamirinejad|first3=Somayeh|last4=Hejri|first4=Maryam|last5=Pirmorad|first5=Tahereh|last6=Yaghmaeezadeh|first6=Hooman|date=2021-05|title=Psychometric properties of Structured Clinical Interview for DSM‐5 Disorders‐Clinician Version (SCID‐5‐CV)|url=https://onlinelibrary.wiley.com/doi/10.1002/brb3.1894|journal=Brain and Behavior|language=en|volume=11|issue=5|doi=10.1002/brb3.1894|issn=2162-3279|pmc=PMC8119811|pmid=33729681}}</ref> |Structured Interview (Adult ) |16+ |Varies |[https://www.columbiapsychiatry.org/research/research-labs/diagnostic-and-assessment-lab/structured-clinical-interview-dsm-disorders-11 Website to purchase] |- | [https://dawba.info/a0.html Development and Well-Being Assessment (DAWBA)] <ref>{{Cite book|url=https://www.worldcat.org/oclc/1160972551|title=Assessment of disorders in childhood and adolescence|date=2020|others=Eric Arden Youngstrom, Mitchell J. Prinstein, Eric J. Mash, Russell A. Barkley|isbn=978-1-4625-4365-6|edition=Fifth edition|location=New York|oclc=1160972551}}</ref> | Structured (child/adolescent and parent) | 11-18 |10-20 minutes for the eating disorder module |[https://osf.io/zpbna/?view_only=245bef061d284c17ab9dedad5a59e1b8 English PDF] [https://dawba.info/py/dawbainfo/b1.py Additional languages] |} '''Note:''' '''L''' = Less than adequate; '''A''' = Adequate; '''G''' = Good; '''E''' = Excellent; '''U''' = Unavailable; '''NA''' = Not applicable ==[[Evidence based assessment/Process phase|'''Process phase''']]== The following section contains a brief overview of treatment options for anorexia nervosa and a list of process and outcome measures for anorexia nervosa. The section includes benchmarks based on published norms for several outcome and severity measures, as well as information about commonly used process measures. Process and outcome measures are used as part of the [[Evidence based assessment/Process phase|process phase]] of assessment. For more information on the differences between process and outcome measures, see the page on the [[Evidence based assessment/Process phase|process phase of assessment]]. ===Process measures=== Body weight is commonly monitored by clinicians throughout the AN treatment process as helping individuals regain and maintain a healthy weight is a primary treatment goal for AN. Many treatment centers have policies prohibiting patients from seeing their weight. Motivational Stages of Change may be used to monitor individuals’ readiness to take action against eating disorder behaviors. It has demonstrated predictive validity in a sample of female adolescents attending eating disorder treatment groups.<ref>{{Cite journal|last=Gusella|first=Joanne|last2=Butler|first2=Gordon|last3=Nichols|first3=Laura|last4=Bird|first4=Debbie|date=2003-01-01|title=A brief questionnaire to assess readiness to change in adolescents with eating disorders: its applications to group therapy|url=http://onlinelibrary.wiley.com/doi/10.1002/erv.481/abstract|journal=European Eating Disorders Review|language=en|volume=11|issue=1|pages=58–71|doi=10.1002/erv.481|issn=1099-0968}}</ref> See Appendix E. === Outcome and severity measures === This table includes clinically significant benchmarks for anorexia nervosa specific outcome measures * Information on how to interpret this table can be [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Process_phase found here]. * Additionally, these [[Evidence based assessment/Vignettes|vignettes]] might be helpful resources for understanding appropriate adaptation of outcome measures in practice. *''<u>For clinically significant change benchmarks for the CBCL, YSR, and TRF total, externalizing, internalizing, and attention benchmarks,</u>'' [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Process_phase&wteswitched=1#Clinically_significant_change_benchmarks_for_widely-used_outcome_measures see here.] {| class="wikitable sortable" border="1" | colspan="8" |'''Clinically significant change benchmarks with common instruments for anorexia nervosa''' |- | colspan="8" span style="font-size:110%; text-align:center;" | <b> Benchmarks Based on Published Norms</b> |- | rowspan="2" style="text-align:center;font-size:130%;" |<b> Measure</b> | rowspan="2" style="text-align:center;font-size:130%;" | <b> Subscale</b> | colspan="3" style="text-align:center;font-size:130%" width="300" | <b> Cut-off scores</b> | colspan="3" style="text-align:center;font-size:120%" | <b> Critical Change <br> (unstandardized scores)</b> |- | style="text-align:center;font-size:110%" |<b> A</b> | style="text-align:center;font-size:110%" |<b> B</b> | style="text-align:center;font-size:110%" |<b> C</b> | style="text-align:center;font-size:110%" |<b> 95%</b> | style="text-align:center;font-size:110%" |<b> 90%</b> | style="text-align:center;font-size:110%" |<b> SE_difference</b> |- | rowspan="5" style="text-align:center;" |'''EDE-Q <ref name=":2">{{Cite journal|last=Mond|first=J. M.|last2=Hay|first2=P. J.|last3=Rodgers|first3=B.|last4=Owen|first4=C.|last5=Beumont|first5=P. J. V.|date=May 2004|title=Validity of the Eating Disorder Examination Questionnaire (EDE-Q) in screening for eating disorders in community samples|url=https://www.ncbi.nlm.nih.gov/pubmed/15033501|journal=Behaviour Research and Therapy|volume=42|issue=5|pages=551–567|doi=10.1016/S0005-7967(03)00161-X|issn=0005-7967|pmid=15033501}}</ref>''' | style="text-align:right;" |''Global'' |1.4 |3.2 |2.3 |.7 |.6 |.3 |- | style="text-align:right;" |''Restraint'' |(-.3) |3.6 |1.8 |1.5 |1.2 |.8 |- | style="text-align:right;" |''Eating Concern'' |.1 |2.0 |1.2 |1.1 |.9 |.6 |- | style="text-align:right;" |''Weight Concern'' |1.5 |3.9 |2.6 |1.0 |.9 |.5 |- | style="text-align:right;" |''Shape Concern'' |2.1 |4.8 |3.2 |.9 |.7 |.4 |- | rowspan="5" style="text-align:center;" |'''EDE <ref name=":2" />''' | style="text-align:right;" |''Global'' |1.7 |2.3 |1.9 |1.9 |1.6 |1.0 |- | style="text-align:right;" |''Restraint'' |.3 |3.3 |1.9 |1.8 |1.5 |.9 |- | style="text-align:right;" |''Eating Concern'' |(-.5) |.9 |.5 |.8 |.7 |.4 |- | style="text-align:right;" |''Weight Concern'' |2.0 |2.8 |2.4 |1.3 |1.1 |.7 |- | style="text-align:right;" |''Shape Concern'' |2.0 |3.2 |2.6 |1.2 |1.0 |.6 |- | rowspan="1" style="text-align:center;" |'''EAT-26 <ref name=":0">{{Cite journal|last=Mintz|first=L. B.|last2=O'Halloran|first2=M. S.|date=2000-06-01|title=The Eating Attitudes Test: validation with DSM-IV eating disorder criteria|url=http://www.ncbi.nlm.nih.gov/pubmed/10900574|journal=Journal of Personality Assessment|volume=74|issue=3|pages=489–503|doi=10.1207/S15327752JPA7403_11|issn=0022-3891|pmid=10900574}}</ref>''' | style="text-align:right;" |''Total'' |6.5 |19.6 |15.0 |7.9 |6.7 |4.0 |} '''Note:''' “A” = Away from the clinical range, “B” = Back into the nonclinical range, “C” = Closer to the nonclinical than clinical mean. '''Search terms:''' [Anorexia Nervosa OR eating disorder] AND [validity OR clinical significance] in Google Scholar === Treatment === {{collapse top| Click here for more information on treatment for AN}} * Treatment of AN typically consists of restoring the individual to a healthy weight and addressing thoughts and behaviors which are related to the eating disorder. It may involve re-nutrition, psychotherapy, nutritional counseling, and medication. * Literature reviews of existing research indicate that evidence supporting AN treatment is lacking. A systematic review of AN treatment efficacy studies by Bulik<ref>{{Cite journal|title = Anorexia nervosa treatment: a systematic review of randomized controlled trials|url = http://www.ncbi.nlm.nih.gov/pubmed/17370290|journal = The International Journal of Eating Disorders|date = 2007-05-01|issn = 0276-3478|pmid = 17370290|pages = 310–320|volume = 40|issue = 4|doi = 10.1002/eat.20367|first = Cynthia M.|last = Bulik|first2 = Nancy D.|last2 = Berkman|first3 = Kimberly A.|last3 = Brownley|first4 = Jan A.|last4 = Sedway|first5 = Kathleen N.|last5 = Lohr}}</ref> found that evidence supporting medications, medications and behavioral interventions, and behavioral interventions alone in adults is weak. * There is moderately strong evidence suggesting that behavioral interventions may be helpful for adolescents. In particular, adolescents may benefit from family therapy. * Clinical trials investigating AN treatment suffer from high rates of attrition, as key features of AN (e.g., denial, fear of weight gain) may contribute to low motivation for remaining in treatment. * More severe cases of AN may be treated in inpatient settings, which are equipped to manage the re-nutrition process and provide medical monitoring. * Partial hospitalization and intensive outpatient programs may provide intermediate levels of treatment intensity to assist individuals in the transition from intensive care to outpatient care after weight restoration. {{collapse bottom}} * Please refer to the page on [https://en.wikipedia.org/wiki/Anorexia_nervosa anorexia nervosa] for more information on available treatment or go to [http://effectivechildtherapy.org/concerns-symptoms-disorders/disorders/eating-body-image-problems/ the Effective Child Therapy page for Eating & Body Image Problems] for a curated resource on effective treatments for anorexia nervosa. == '''External resources''' == # [http://apps.who.int/classifications/icd10/browse/2010/en#/F50.0 ICD-10 diagnostic criteria] # [https://en.wikiversity.org/w/index.php?title=Helping_Give_Away_Psychological_Science/Resources/Annotated_List_of_Where_and_How_to_Find_a_Therapist&wteswitched=1#Other_low-cost_options Find-a-Therapist] ##This is a curated list of find-a-therapist websites where you can find a provider # NIMH: [https://www.nimh.nih.gov/health/publications/eating-disorders/index.shtml ''Eating Disorders--About More Than Food''] and [https://www.nimh.nih.gov/health/topics/eating-disorders/index.shtml ''Eating Disorders''] ##These NIMH website posts provide more information on anorexia nervosa #[https://www.hopkinsmedicine.org/psychiatry/specialty_areas/eating_disorders/ John's Hopkins Resource] (guide about anorexia nervosa, treatment, and more) # OMIM (Online Mendelian Inheritance in Man) ##[https://www.omim.org/entry/606788?search=anorexia%20nervosa&highlight=nervosa%20anorexia Anorexia nervosa] #[http://effectivechildtherapy.org/concerns-symptoms-disorders/disorders/eating-body-image-problems/ Effective Child Therapy page for anorexia nervosa] ##Effective Child Therapy is website sponsored by Division 53 of the American Psychological Association (APA), or The [https://sccap53.org Society of Clinical Child and Adolescent Psychology] (SCCAP), in collaboration with the Association for Behavioral and Cognitive Therapies (ABCT). Use for information on symptoms and available treatments. == '''References''' == {{collapse top|Click here for references}} {{Reflist|30em}} [[Category:Psychological disorder portfolios|{{SUBPAGENAME}}]] {{collapse bottom}} 2pplcoqd6vomxt0jdptzmqmh09dx6hv 2413987 2413986 2022-08-12T15:47:24Z Aherman012 2943941 /* Psychometric properties of screening instruments for anorexia nervosa */ wikitext text/x-wiki <noinclude>{{Helping Give Away Psychological Science Banner}}</noinclude> {{medical disclaimer}} {{:{{BASEPAGENAME}}/Sidebar}} ==[[Evidence based assessment/Portfolio template/What is a "portfolio"|'''What is a "portfolio"?''']]== For background information on what assessment portfolios are, click the link in the heading above. Want even 'more' information about this topic? There's an extended version of this page [[Evidence-based assessment/Anorexia nervosa (assessment portfolio)/extended version|here]]. == [[Evidence based assessment/Preparation phase|'''Preparation phase''']] == === Diagnostic criteria for anorexia nervosa === {{blockquotetop}} '''ICD-11 Criteria''' Anorexia Nervosa is characterized by significantly low body weight, which is less than minimal normal/expected weight for the individual’s height, sex, age and developmental stage (body mass index (BMI) less than 18.5 kg/m2 in adults and BMI-for-age under fifth percentile in children and adolescents) that is not due to another health condition or to the unavailability of food. Low body weight is accompanied by a persistent pattern of behaviors to prevent restoration of normal weight, which may include behaviors aimed at reducing energy intake (restricted eating), purging behaviors (e.g., self-induced vomiting, misuse of laxatives), and behaviors aimed at increasing energy expenditure (e.g., excessive exercise), typically associated with a fear of weight gain. Low body weight or shape is central to the person's self-evaluation or is inaccurately perceived to be normal or even excessive. '''Changes in DSM-5''' * The diagnostic criteria for anorexia nervosa changed slightly from [[DSM-IV]] to [[w:Diagnostic_and_Statistical_Manual_of_Mental_Disorders#DSM-IV-TR_.282000.29|DSM-5]]. Summaries are available [http://www.dsm5.org/Documents/changes%20from%20dsm-iv-tr%20to%20dsm-5.pdf here] and [[w:DSM-5|here]]. {{blockquotebottom}} === Base rates of anorexia nervosa in different populations and clinical settings === This section describes the demographic setting of the population(s) sampled, base rates of diagnosis such as prevalence rates, country/region sampled, and the diagnostic method that was used. Using this information, clinicians will be able to anchor the rate of adolescent depression that they are likely to see in their clinical practice. * '''''To see prevalence rates across multiple disorders,''''' [[Evidence based assessment/Preparation phase#Base rates for transdiagnostic comparison|'''''click here.''''']] {| class="wikitable sortable" |- ! Demography ! Setting (Reference) ! Base Rate ! Diagnostic Method |- |Nationally representative US sample of adults |Non-clinical: Population-based (NCS-R)<ref>Hudson, James I.; Hiripi, Eva; Pope, Harrison G.; Kessler, Ronald C. (2007-02-01). "The prevalence and correlates of eating disorders in the National Comorbidity Survey Replication".''Biological Psychiatry'' '''61''' (3): 348–358. doi:10.1016/j.biopsych.2006.03.040. ISSN 0006-3223. PMC 1892232. <nowiki>PMID 16815322</nowiki></ref> |.9% Female, .3% Male |World Health Organization-Clinical International Diagnostic Interview (WHO-CIDI) |- |Nationally representative US sample of adolescents |Non-clinical: Population-based (NCS-A)<ref>Swanson, Sonja A.; Crow, Scott J.; Le Grange, Daniel; Swendsen, Joel; Merikangas, Kathleen R. (2011-07-01). "Prevalence and correlates of eating disorders in adolescents. Results from the national comorbidity survey replication adolescent supplement". ''Archives of General Psychiatry'' '''68''' (7): 714–723. doi:10.1001/archgenpsychiatry.2011.22. ISSN 1538-3636.<nowiki>PMID 21383252</nowiki></ref> |.3% Female, .3% Male |WHO-CIDI |- |Nationally representative US sample of 9- and 10-year old children |Non-clinical: US Population-based prevalence (Adolescent Brain Cognitive Development (ABCD) study<ref>{{Cite journal|last=Rozzell|first=Kaitlin|last2=Moon|first2=Da Yeoun|last3=Klimek|first3=Patrycja|last4=Brown|first4=Tiffany|last5=Blashill|first5=Aaron J.|date=2019-01-01|title=Prevalence of Eating Disorders Among US Children Aged 9 to 10 Years: Data From the Adolescent Brain Cognitive Development (ABCD) Study|url=http://archpedi.jamanetwork.com/article.aspx?doi=10.1001/jamapediatrics.2018.3678|journal=JAMA Pediatrics|language=en|volume=173|issue=1|pages=100|doi=10.1001/jamapediatrics.2018.3678|issn=2168-6203|pmc=PMC6583451|pmid=30476983}}</ref> |0.1%, no gender differences |DSM-5 using Kiddie Schedule for Affective Disorders and Schizophrenia (KSADS) |- |Latino Households in the US |Non-clinical: Latinos in US<ref>Alegria, Margarita; Woo, Meghan; Cao, Zhun; Torres, Maria; Meng, Xiao-li; Striegel-Moore, Ruth (2007-11-01). "Prevalence and correlates of eating disorders in Latinos in the United States".''The International Journal of Eating Disorders''. 40 Suppl: S15–21. doi:10.1002/eat.20406. ISSN 0276-3478. PMC 2680162. <nowiki>PMID 17584870</nowiki></ref> |.12% Female, .03% Male |WHO-CIDI |- |National probability sample of adult and adolescent African Americans and Caribbean Black people |Non-clinical: African Americans and Caribbean Black people in the US (NSAL)<ref>Taylor, Jacquelyn Y.; Caldwell, Cleopatra Howard; Baser, Raymond E.; Faison, Nakesha; Jackson, James S. (2007-11-01). "Prevalence of eating disorders among Blacks in the National Survey of American Life". ''The International Journal of Eating Disorders''. 40 Suppl: S10–14. doi:10.1002/eat.20451. ISSN 0276-3478. PMC 2882704. <nowiki>PMID 17879287</nowiki></ref> |.14% Female, .2% Male |WHO-CIDI |- |Asian American adults in US households |Non-clinical: National Latino and Asian American Study (NLAAS) |.12% Female, .05% Male |WHO-CIDI |- | US African American college females | Non-clinical; college students<ref>Tyler ID. A true picture of eating disorders among African American women: a review of literature. ABNF J. 2003;14(3):73-4.</ref> || .0% || Eating Disorder Diagnostic Questionnaire (EDD-Q) |- | US Female Adolescents | Non-clinical; Adolescents<ref>Stice, E., Becker, C. B., & Yokum, S. (2013). Eating disorder prevention: Current evidence-base and future directions. ''Int. J. Eat. Disord. International Journal of Eating Disorders,'' ''46''(5), 478-485.</ref> || .8% || Eating Disorder Diagnosis Interview (EDDI) |- | US Division-I Varsity Student Athletes | Non-clinical; student-athletes<ref>Johnson C, Powers PS, Dick R. Athletes and eating disorders: the national collegiate athletic association study. Int J Eat Disord 1999;26:179e88.</ref> || .0% || Eating Disorder Inventory-2 (EDI-2) |- | Active duty females in US Army, Navy, Airforce, and Marines | Non-clinical; Military<ref>McNulty, PAF. (2001). Prevalence and contributing factors of eating disorder behaviors in active duty service women in the Army, Navy, Air Force and Marines. Military Medicine, 166(1), 53-58. </ref> || 1.1% || EDI-2 |- |US Caucasian female same-sex twins |Non-clinical; Commonwealth of Virginia Mid-Atlantic Twin Registry (MATR)<ref>Kendler KS, Walters EE, Neale MC, Kessler R, Heath A, Eaves L. The structure of genetic and environmental risk factors for six major psychiatric disorders in women. Archives of general psychiatry. 1995;52:374–383.</ref> |1.62% (narrow), 3.70% (broad) |Structured Clinical Interview for DSM Disorders (SCID) |- |South Australian older adolescents and adults |Non-clinical; Health Omnibus Survey (HOS) |.46% (3 months; combined) |Eating Disorder Examination (EDE) |- |US Military |Military<ref>{{Cite journal|title=Diagnosed eating disorders in the U.S. Military: a nine year review|url=http://www.ncbi.nlm.nih.gov/pubmed/18821361|journal=Eating Disorders|date=2008-12-01|issn=1532-530X|pmid=18821361|pages=363–377|volume=16|issue=5|doi=10.1080/10640260802370523|first=Amanda J.|last=Antczak|first2=Teresa L.|last2=Brininger}}</ref> |.04% (combined) |ICD codes from electronic records |- |US Military Academy cadets |Non-clinical; Military |.02% (7 years) Female, 0.0% (7 years) Males |[https://www.eat-26.com/ Eating Attitudes Test- 26 items] (EAT-26)<ref>{{Cite web|url=https://www.eat-26.com/|title=EAT-26: Eating Attitudes Test & Eating Disorder Testing – Use the EAT-26 to help you determine if you need to speak to a mental health professional to get help for an eating disorder.|last=admin|language=en|access-date=2022-05-30}}</ref> |- |US Navy female nurses |Non-clinical; Military |1.1% (current & past) Female |DSM-III |- |US veterans |Non-clinical; Military |.04% Female, .005% Males |ICD-9-CM |- |Active duty males in US Navy |Non-clinical; Military |2.5% Males |N/A |- |US alcohol-dependent adults from San Diego, St. Lois, Iowa City, Farmington, New York, & Indianapolis |Clinical; Collaborative Study on the Genetics of Alcoholism (COGA)<ref>{{Cite journal|title=Anorexia nervosa and bulimia nervosa in alcohol-dependent men and women and their relatives|url=http://www.ncbi.nlm.nih.gov/pubmed/8540597|journal=The American Journal of Psychiatry|date=1996-01-01|issn=0002-953X|pmid=8540597|pages=74–82|volume=153|issue=1|doi=10.1176/ajp.153.1.74|first=M. A.|last=Schuckit|first2=J. E.|last2=Tipp|first3=R. M.|last3=Anthenelli|first4=K. K.|last4=Bucholz|first5=V. M.|last5=Hesselbrock|first6=J. I.|last6=Nurnberger}}</ref> |1.41% (lifetime) Female, .00% (lifetime) Male |SSAGA |- |Healthcare provider records |Non-clinical; healthcare members |.0269% (current) | |- |US high school students in west central Oregon |Non-clinical; high school students |. 00% (point), .45% (lifetime) Female .00% (point), .00% (lifetime) Males |DSM-III-R₄ |- |Canadian treatment-seeking substance users |Clinical; substance users |.4% (lifetime), .3% (current) Female .4% (lifetime), .3% (current) Males |DIS₉ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''Europe''' |- |Adolescent females residing in Navarra, Spain |Non-clinical; adolescents |.3% Female |EAT-40₃ |- |Adolescents in secondary schools in Sør-Trøndelag, County in Norway |Non-clinical; adolescents |.7% (lifetime) Female, .2% Male |SEDs₁₀ |- |Adolescents in a comprehensive school in Ostrobothnia district in Finland |Non-clinical; adolescents |.7% (point; age 15), 1.8% (lifetime, age 15), .00% (point, age 18), 2.6% (lifetime, age 18), .9% (3 years) Female .00% (point & lifetime) Males |RAB-T₁₁&nbsp;& RAB-R₁₂ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''Australia''' |- |Adolescent females residing in Victoria, Australia |Non-clinical; adolescents |.00% (full), 1.8% (partial) Female |BET₁₃ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''Central & South America''' |- |Mexican first & second year college females |Non-clinical; college students |.00% Female |EAT-40₃ |- | | colspan="3" style="font-size:110%; text-align:center;" |'''East Asia''' |- |Adolescent and adult Japanese patients at a university hospital |Clinical; eating disorder patients |.53% Female |DSM-III-R₄ |- |Korean adults |Non-clinical; Korean Epidemiologic Catchment Area (KECA) Study |.1% (lifetime), .1% (12 months) Female .2% (lifetime), .00% (12 months) Males |K-CIDI₁₅&nbsp;2.1 |- |Alcohol-dependent adults |Centers participating in the Collaborative Study on the Genetics of Alcoholism in San Diego; St. Louis; Iowa City; Farmington, CN; New York; & Indianapolis |1.41% Females |Semi-Structured Assessment for the Genetics of Alcoholism; criteria based on DSM-III-R |} ==[[Evidence based assessment/Prediction phase|'''Prediction phase''']]== === Psychometric properties of screening instruments for anorexia nervosa === The following section contains a list of screening and diagnostic instruments for anorexia nervosa. The section includes administration information, psychometric data, and PDFs or links to the screenings. * Screenings are used as part of the [[Evidence based assessment/Prediction phase|prediction phase]] of assessment; for more information on interpretation of this data, or how screenings fit in to the assessment process, click [[Evidence based assessment/Prediction phase|here.]] * ''For a list of more broadly reaching screening instruments, [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prediction_phase&wteswitched=1#Psychometric_properties_of_common_screening_instruments '''click here.''']'' {| class="wikitable" |- ! Measure !Format (Reporter) !Age Range !Administration/ Completion Time !Where to Access |- |[[wikipedia:Eating_Disorder_Examination_Interview|Eating Disorder Examination Questionnaire (EDE-Q)]]<ref>{{Cite journal|last=Cooper|first=Zafra|last2=Fairburn|first2=Christopher|date=1987-01|title=The eating disorder examination: A semi-structured interview for the assessment of the specific psychopathology of eating disorders|url=http://dx.doi.org/10.1002/1098-108x(198701)6:1<1::aid-eat2260060102>3.0.co;2-9|journal=International Journal of Eating Disorders|volume=6|issue=1|pages=1–8|doi=10.1002/1098-108x(198701)6:1<1::aid-eat2260060102>3.0.co;2-9|issn=0276-3478}}</ref> |Questionnaire (Patient) |14+ |15-20 min | [http://www.corc.uk.net/media/1273/ede-q_quesionnaire.pdf PDF] |- |[[wikipedia:Eating_Disorder_Diagnostic_Scale|EDDS (Eating Disorder Diagnosis Scale)]]<ref>{{Cite journal|last=Stice|first=Eric|last2=Telch|first2=Christy F.|last3=Rizvi|first3=Shireen L.|date=2000|title=Development and validation of the Eating Disorder Diagnostic Scale: A brief self-report measure of anorexia, bulimia, and binge-eating disorder.|url=http://doi.apa.org/getdoi.cfm?doi=10.1037/1040-3590.12.2.123|journal=Psychological Assessment|language=en|volume=12|issue=2|pages=123–131|doi=10.1037/1040-3590.12.2.123|issn=1939-134X}}</ref> |Questionnaire (Patient) |13 - 65 |10-15 min | [http://www.ori.org/files/Static%20Page%20Files/EDDSDSM-5_10_14.pdf PDF] |- |Eating Attitudes Test- 26(EAT-26; Adult version)<ref>{{Cite journal|last=Garner|first=David M.|last2=Garfinkel|first2=Paul E.|date=1979-05|title=The Eating Attitudes Test: an index of the symptoms of anorexia nervosa|url=http://dx.doi.org/10.1017/s0033291700030762|journal=Psychological Medicine|volume=9|issue=2|pages=273–279|doi=10.1017/s0033291700030762|issn=0033-2917}}</ref> Child Eating Attitudes Test - 26 (ChEAT-26; child version)<ref>{{Cite journal|last=Almeida|first=M.C.|last2=Carvalho|first2=D.L.D.B.|last3=Rigolino|first3=R.|date=2012-07|title=Reliability of a Brazilian version of children's eating attitude test|url=http://dx.doi.org/10.1016/j.neurenf.2012.04.196|journal=Neuropsychiatrie de l'Enfance et de l'Adolescence|volume=60|issue=5|pages=S158|doi=10.1016/j.neurenf.2012.04.196|issn=0222-9617}}</ref> |Questionnaire (Patient) |13+ (adult version) 8 -13 (child version) |5-10 min |PDFs * [https://www.eat-26.com/eat-26/ Adult Version PDF] * [http://www.1000livesplus.wales.nhs.uk/sitesplus/documents/1011/ChEAT.pdf Child Version PDF] |} <ref>Hunsley, J., & Mash, E. J. (2008). Guide to Assessments that Work. Cary, NC, USA: Oxford University Press, USA. Retrieved from <nowiki>http://www.ebrary.com</nowiki></ref>'''Note:''' '''L''' = Less than adequate; '''A''' = Adequate; '''G''' = Good; '''E''' = Excellent; '''U''' = Unavailable; '''NA''' = Not applicable ===Likelihood ratios and AUCs of screening instruments for anorexia nervosa=== * ''For a list of the likelihood ratios for more broadly reaching screening instruments, [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prediction_phase&wteswitched=1#Likelihood_ratios_and_AUCs_of_common_screening_instruments '''click here.''']'' {| class="wikitable sortable" border="1" |- ! <ref name=":4">{{Cite journal|last=Mintz|first=L. B.|last2=O'Halloran|first2=M. S.|date=June 2000|title=The Eating Attitudes Test: validation with DSM-IV eating disorder criteria|url=https://www.ncbi.nlm.nih.gov/pubmed/10900574|journal=Journal of Personality Assessment|volume=74|issue=3|pages=489–503|doi=10.1207/S15327752JPA7403_11|issn=0022-3891|pmid=10900574}}</ref>Screening Measure (Primary Reference) ! AUC ! DiLR+ (Score) ! DiLR- (Score) !Clinical Generalizability !Where to access |- |Serum leptin level<ref name=":7">{{Cite journal|last=Föcker|first=M.|last2=Timmesfeld|first2=N.|last3=Scherag|first3=S.|last4=Bühren|first4=K.|last5=Langkamp|first5=M.|last6=Dempfle|first6=A.|last7=Sheridan|first7=E. M.|last8=Zwaan|first8=M. de|last9=Fleischhaker|first9=C.|date=2011-04-01|title=Screening for anorexia nervosa via measurement of serum leptin levels|url=https://link.springer.com/article/10.1007/s00702-010-0551-z|journal=Journal of Neural Transmission|language=en|volume=118|issue=4|pages=571–578|doi=10.1007/s00702-010-0551-z|issn=0300-9564}}</ref> |0.984 (N=139) |14.72 (<2.31) |0.10 (2.31+) |Adolescent and adult patients in the acute phase of AN according to the DSM-IV and no AN pretreatment versus healthy lean female volunteer university students. |None |- |Body Mass Index (BMI)<ref name=":7" /> |0.936 (N=139) |5.89 (<17.10) |0.11 (17.10+) |Adolescent and adult patients in the acute phase of AN according to the DSM-IV and no AN pretreatment versus healthy lean female volunteer university students. |None |- |EAT-26&nbsp;<ref name=":4" /><ref>{{Cite journal|title = The eating attitudes test: psychometric features and clinical correlates|url = http://www.ncbi.nlm.nih.gov/pubmed/6961471|journal = Psychological Medicine|date = 1982-11-01|issn = 0033-2917|pmid = 6961471|pages = 871–878|volume = 12|issue = 4|first = D. M.|last = Garner|first2 = M. P.|last2 = Olmsted|first3 = Y.|last3 = Bohr|first4 = P. E.|last4 = Garfinkel}}</ref> |.90 (N=129) |12.83 (20+) |.24 (<20) |Low-moderate: College women with no eating disorder versus college women with a DSM-IV eating disorder. Eating disorders were not separated. |PDFs * [https://www.eat-26.com/eat-26/ Adult Version PDF] * [http://www.1000livesplus.wales.nhs.uk/sitesplus/documents/1011/ChEAT.pdf Child Version PDF] |- |EDE-Q&nbsp;<ref name=":1">{{Cite journal|title = Assessment of eating disorders: interview or self-report questionnaire?|url = http://www.ncbi.nlm.nih.gov/pubmed/7866415|journal = The International Journal of Eating Disorders|date = 1994-12-01|issn = 0276-3478|pmid = 7866415|pages = 363–370|volume = 16|issue = 4|first = C. G.|last = Fairburn|first2 = S. J.|last2 = Beglin}}</ref> |.96 &nbsp;<ref name=":1" />(N=1170) | 6.57 (2.3+)<ref name=":5">{{Cite journal|last=Fairburn|first=C. G.|last2=Beglin|first2=S. J.|date=December 1994|title=Assessment of eating disorders: interview or self-report questionnaire?|url=https://www.ncbi.nlm.nih.gov/pubmed/7866415|journal=The International Journal of Eating Disorders|volume=16|issue=4|pages=363–370|issn=0276-3478|pmid=7866415}}</ref> | 0.09 (<2.3)<ref name=":5" /> |Moderate: Dutch treatment-seeking females meeting DSM-IV criteria for an eating disorder versus female adult general population sample recruited through advertisements and personal contacts. Eating disorders were not separated.&nbsp;<ref name=":1" /> Moderate: “Clinically significant eating disorder” from a community sample versus female adults individuals without “clinically significant eating disorder” from same sample. Eating disorders were not separated.<ref name=":5" /> |[http://www.corc.uk.net/media/1273/ede-q_quesionnaire.pdf PDF] |} === Interpreting anorexia nervosa screening measure scores === * For information on interpreting screening measure scores, click [[Evidence based assessment/Prediction phase#Interpreting screening measure scores|here.]] * Also see the page on [https://en.wikipedia.org/wiki/Likelihood_ratios_in_diagnostic_testing likelihood ratios in diagnostic testing] for more information. ==[[Evidence based assessment/Prescription phase|'''Prescription phase''']]== ===Gold standard diagnostic interviews=== * For a list of broad reaching diagnostic interviews sortable by disorder with PDFs (if applicable), [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prescription_phase&wteswitched=1#Common_Diagnostic_Interviews click here.] ===Recommended diagnostic interviews for anorexia nervosa=== {| class="wikitable sortable" border="1" ! colspan="5" |Diagnostic instruments for anorexia nervosa |- ! Measure ! Format (Reporter) ! Age Range ! Administration/ Completion Time !Where to access |- |[https://www.credo-oxford.com/7.2.html Eating Disorder Examination (EDE)] <ref>{{Cite book|url=https://www.worldcat.org/oclc/1160972551|title=Assessment of disorders in childhood and adolescence|date=2020|others=Eric Arden Youngstrom, Mitchell J. Prinstein, Eric J. Mash, Russell A. Barkley|isbn=978-1-4625-4365-6|edition=Fifth edition|location=New York|oclc=1160972551}}</ref> <ref>{{Cite book|url=https://www.worldcat.org/oclc/314222270|title=A guide to assessments that work|date=2008|publisher=Oxford University Press|others=John Hunsley, Eric J. Mash|isbn=0-19-804245-0|location=New York|oclc=314222270}}</ref> |Semistructured (child and adult) |8-16 (child version) 16+ (adult version) |45-75 minutes |PDFs * [https://www.phenxtoolkit.org/protocols/view/230101 Child version PDF] * [https://www.credo-oxford.com/7.2.html Adult version PDF] |- |Structured Clinical Interview for DSM-5-Clinician Version (SCID-5-CV)<ref>{{Cite journal|last=Shabani|first=Amir|last2=Masoumian|first2=Samira|last3=Zamirinejad|first3=Somayeh|last4=Hejri|first4=Maryam|last5=Pirmorad|first5=Tahereh|last6=Yaghmaeezadeh|first6=Hooman|date=2021-05|title=Psychometric properties of Structured Clinical Interview for DSM‐5 Disorders‐Clinician Version (SCID‐5‐CV)|url=https://onlinelibrary.wiley.com/doi/10.1002/brb3.1894|journal=Brain and Behavior|language=en|volume=11|issue=5|doi=10.1002/brb3.1894|issn=2162-3279|pmc=PMC8119811|pmid=33729681}}</ref> |Structured Interview (Adult ) |16+ |Varies |[https://www.columbiapsychiatry.org/research/research-labs/diagnostic-and-assessment-lab/structured-clinical-interview-dsm-disorders-11 Website to purchase] |- | [https://dawba.info/a0.html Development and Well-Being Assessment (DAWBA)] <ref>{{Cite book|url=https://www.worldcat.org/oclc/1160972551|title=Assessment of disorders in childhood and adolescence|date=2020|others=Eric Arden Youngstrom, Mitchell J. Prinstein, Eric J. Mash, Russell A. Barkley|isbn=978-1-4625-4365-6|edition=Fifth edition|location=New York|oclc=1160972551}}</ref> | Structured (child/adolescent and parent) | 11-18 |10-20 minutes for the eating disorder module |[https://osf.io/zpbna/?view_only=245bef061d284c17ab9dedad5a59e1b8 English PDF] [https://dawba.info/py/dawbainfo/b1.py Additional languages] |} '''Note:''' '''L''' = Less than adequate; '''A''' = Adequate; '''G''' = Good; '''E''' = Excellent; '''U''' = Unavailable; '''NA''' = Not applicable ==[[Evidence based assessment/Process phase|'''Process phase''']]== The following section contains a brief overview of treatment options for anorexia nervosa and a list of process and outcome measures for anorexia nervosa. The section includes benchmarks based on published norms for several outcome and severity measures, as well as information about commonly used process measures. Process and outcome measures are used as part of the [[Evidence based assessment/Process phase|process phase]] of assessment. For more information on the differences between process and outcome measures, see the page on the [[Evidence based assessment/Process phase|process phase of assessment]]. ===Process measures=== Body weight is commonly monitored by clinicians throughout the AN treatment process as helping individuals regain and maintain a healthy weight is a primary treatment goal for AN. Many treatment centers have policies prohibiting patients from seeing their weight. Motivational Stages of Change may be used to monitor individuals’ readiness to take action against eating disorder behaviors. It has demonstrated predictive validity in a sample of female adolescents attending eating disorder treatment groups.<ref>{{Cite journal|last=Gusella|first=Joanne|last2=Butler|first2=Gordon|last3=Nichols|first3=Laura|last4=Bird|first4=Debbie|date=2003-01-01|title=A brief questionnaire to assess readiness to change in adolescents with eating disorders: its applications to group therapy|url=http://onlinelibrary.wiley.com/doi/10.1002/erv.481/abstract|journal=European Eating Disorders Review|language=en|volume=11|issue=1|pages=58–71|doi=10.1002/erv.481|issn=1099-0968}}</ref> See Appendix E. === Outcome and severity measures === This table includes clinically significant benchmarks for anorexia nervosa specific outcome measures * Information on how to interpret this table can be [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Process_phase found here]. * Additionally, these [[Evidence based assessment/Vignettes|vignettes]] might be helpful resources for understanding appropriate adaptation of outcome measures in practice. *''<u>For clinically significant change benchmarks for the CBCL, YSR, and TRF total, externalizing, internalizing, and attention benchmarks,</u>'' [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Process_phase&wteswitched=1#Clinically_significant_change_benchmarks_for_widely-used_outcome_measures see here.] {| class="wikitable sortable" border="1" | colspan="8" |'''Clinically significant change benchmarks with common instruments for anorexia nervosa''' |- | colspan="8" span style="font-size:110%; text-align:center;" | <b> Benchmarks Based on Published Norms</b> |- | rowspan="2" style="text-align:center;font-size:130%;" |<b> Measure</b> | rowspan="2" style="text-align:center;font-size:130%;" | <b> Subscale</b> | colspan="3" style="text-align:center;font-size:130%" width="300" | <b> Cut-off scores</b> | colspan="3" style="text-align:center;font-size:120%" | <b> Critical Change <br> (unstandardized scores)</b> |- | style="text-align:center;font-size:110%" |<b> A</b> | style="text-align:center;font-size:110%" |<b> B</b> | style="text-align:center;font-size:110%" |<b> C</b> | style="text-align:center;font-size:110%" |<b> 95%</b> | style="text-align:center;font-size:110%" |<b> 90%</b> | style="text-align:center;font-size:110%" |<b> SE_difference</b> |- | rowspan="5" style="text-align:center;" |'''EDE-Q <ref name=":2">{{Cite journal|last=Mond|first=J. M.|last2=Hay|first2=P. J.|last3=Rodgers|first3=B.|last4=Owen|first4=C.|last5=Beumont|first5=P. J. V.|date=May 2004|title=Validity of the Eating Disorder Examination Questionnaire (EDE-Q) in screening for eating disorders in community samples|url=https://www.ncbi.nlm.nih.gov/pubmed/15033501|journal=Behaviour Research and Therapy|volume=42|issue=5|pages=551–567|doi=10.1016/S0005-7967(03)00161-X|issn=0005-7967|pmid=15033501}}</ref>''' | style="text-align:right;" |''Global'' |1.4 |3.2 |2.3 |.7 |.6 |.3 |- | style="text-align:right;" |''Restraint'' |(-.3) |3.6 |1.8 |1.5 |1.2 |.8 |- | style="text-align:right;" |''Eating Concern'' |.1 |2.0 |1.2 |1.1 |.9 |.6 |- | style="text-align:right;" |''Weight Concern'' |1.5 |3.9 |2.6 |1.0 |.9 |.5 |- | style="text-align:right;" |''Shape Concern'' |2.1 |4.8 |3.2 |.9 |.7 |.4 |- | rowspan="5" style="text-align:center;" |'''EDE <ref name=":2" />''' | style="text-align:right;" |''Global'' |1.7 |2.3 |1.9 |1.9 |1.6 |1.0 |- | style="text-align:right;" |''Restraint'' |.3 |3.3 |1.9 |1.8 |1.5 |.9 |- | style="text-align:right;" |''Eating Concern'' |(-.5) |.9 |.5 |.8 |.7 |.4 |- | style="text-align:right;" |''Weight Concern'' |2.0 |2.8 |2.4 |1.3 |1.1 |.7 |- | style="text-align:right;" |''Shape Concern'' |2.0 |3.2 |2.6 |1.2 |1.0 |.6 |- | rowspan="1" style="text-align:center;" |'''EAT-26 <ref name=":0">{{Cite journal|last=Mintz|first=L. B.|last2=O'Halloran|first2=M. S.|date=2000-06-01|title=The Eating Attitudes Test: validation with DSM-IV eating disorder criteria|url=http://www.ncbi.nlm.nih.gov/pubmed/10900574|journal=Journal of Personality Assessment|volume=74|issue=3|pages=489–503|doi=10.1207/S15327752JPA7403_11|issn=0022-3891|pmid=10900574}}</ref>''' | style="text-align:right;" |''Total'' |6.5 |19.6 |15.0 |7.9 |6.7 |4.0 |} '''Note:''' “A” = Away from the clinical range, “B” = Back into the nonclinical range, “C” = Closer to the nonclinical than clinical mean. '''Search terms:''' [Anorexia Nervosa OR eating disorder] AND [validity OR clinical significance] in Google Scholar === Treatment === {{collapse top| Click here for more information on treatment for AN}} * Treatment of AN typically consists of restoring the individual to a healthy weight and addressing thoughts and behaviors which are related to the eating disorder. It may involve re-nutrition, psychotherapy, nutritional counseling, and medication. * Literature reviews of existing research indicate that evidence supporting AN treatment is lacking. A systematic review of AN treatment efficacy studies by Bulik<ref>{{Cite journal|title = Anorexia nervosa treatment: a systematic review of randomized controlled trials|url = http://www.ncbi.nlm.nih.gov/pubmed/17370290|journal = The International Journal of Eating Disorders|date = 2007-05-01|issn = 0276-3478|pmid = 17370290|pages = 310–320|volume = 40|issue = 4|doi = 10.1002/eat.20367|first = Cynthia M.|last = Bulik|first2 = Nancy D.|last2 = Berkman|first3 = Kimberly A.|last3 = Brownley|first4 = Jan A.|last4 = Sedway|first5 = Kathleen N.|last5 = Lohr}}</ref> found that evidence supporting medications, medications and behavioral interventions, and behavioral interventions alone in adults is weak. * There is moderately strong evidence suggesting that behavioral interventions may be helpful for adolescents. In particular, adolescents may benefit from family therapy. * Clinical trials investigating AN treatment suffer from high rates of attrition, as key features of AN (e.g., denial, fear of weight gain) may contribute to low motivation for remaining in treatment. * More severe cases of AN may be treated in inpatient settings, which are equipped to manage the re-nutrition process and provide medical monitoring. * Partial hospitalization and intensive outpatient programs may provide intermediate levels of treatment intensity to assist individuals in the transition from intensive care to outpatient care after weight restoration. {{collapse bottom}} * Please refer to the page on [https://en.wikipedia.org/wiki/Anorexia_nervosa anorexia nervosa] for more information on available treatment or go to [http://effectivechildtherapy.org/concerns-symptoms-disorders/disorders/eating-body-image-problems/ the Effective Child Therapy page for Eating & Body Image Problems] for a curated resource on effective treatments for anorexia nervosa. == '''External resources''' == # [http://apps.who.int/classifications/icd10/browse/2010/en#/F50.0 ICD-10 diagnostic criteria] # [https://en.wikiversity.org/w/index.php?title=Helping_Give_Away_Psychological_Science/Resources/Annotated_List_of_Where_and_How_to_Find_a_Therapist&wteswitched=1#Other_low-cost_options Find-a-Therapist] ##This is a curated list of find-a-therapist websites where you can find a provider # NIMH: [https://www.nimh.nih.gov/health/publications/eating-disorders/index.shtml ''Eating Disorders--About More Than Food''] and [https://www.nimh.nih.gov/health/topics/eating-disorders/index.shtml ''Eating Disorders''] ##These NIMH website posts provide more information on anorexia nervosa #[https://www.hopkinsmedicine.org/psychiatry/specialty_areas/eating_disorders/ John's Hopkins Resource] (guide about anorexia nervosa, treatment, and more) # OMIM (Online Mendelian Inheritance in Man) ##[https://www.omim.org/entry/606788?search=anorexia%20nervosa&highlight=nervosa%20anorexia Anorexia nervosa] #[http://effectivechildtherapy.org/concerns-symptoms-disorders/disorders/eating-body-image-problems/ Effective Child Therapy page for anorexia nervosa] ##Effective Child Therapy is website sponsored by Division 53 of the American Psychological Association (APA), or The [https://sccap53.org Society of Clinical Child and Adolescent Psychology] (SCCAP), in collaboration with the Association for Behavioral and Cognitive Therapies (ABCT). Use for information on symptoms and available treatments. == '''References''' == {{collapse top|Click here for references}} {{Reflist|30em}} [[Category:Psychological disorder portfolios|{{SUBPAGENAME}}]] {{collapse bottom}} beqovhu0c30c0fpbavxg39jmppujual 0 207103 2414009 2411974 2022-08-12T22:22:25Z Aherman012 2943941 /* Base rates of GAD in different clinical settings */ wikitext text/x-wiki <noinclude>{{Helping Give Away Psychological Science Banner}}</noinclude> {{medical disclaimer}} {{:{{BASEPAGENAME}}/Sidebar}} ==[[Evidence based assessment/Portfolio template/What is a "portfolio"|'''What is a "portfolio"?''']]== * For background information on what assessment portfolios are, click the link in the heading above. Want even 'more' information about this topic? There's an extended version of this page [[Evidence-based assessment/Generalized anxiety disorder (assessment portfolio)/extended version|here]]. ==[[Evidence based assessment/Preparation phase|'''Preparation phase''']]== === Diagnostic criteria for generalized anxiety disorder === {{blockquotetop}} <big>'''ICD-11 Diagnostic Criteria<ref>https://icd.who.int/browse11/l-m/en#/http://id.who.int/icd/entity/1712535455</ref>'''</big> *Generalised anxiety disorder is characterized by marked symptoms of anxiety that persist for at least several months, for more days than not, manifested by either general apprehension (i.e. ‘free-floating anxiety’) or excessive worry focused on multiple everyday events, most often concerning family, health, finances, and school or work, together with additional symptoms such as muscular tension or motor restlessness, sympathetic autonomic over-activity, subjective experience of nervousness, difficulty maintaining concentration, irritability, or sleep disturbance. The symptoms result in significant distress or significant impairment in personal, family, social, educational, occupational, or other important areas of functioning. The symptoms are not a manifestation of another health condition and are not due to the effects of a substance or medication on the central nervous system. '''Changes in DSM-5''' * The diagnostic criteria for generalized anxiety disorder changed slightly from DSM-IV-TR to DSM-5. Summaries are available [https://www.ncbi.nlm.nih.gov/books/NBK519712/table/ch3.t9/?report=objectonly here]. {{blockquotebottom}} === Base rates of GAD in different clinical settings === This section describes the demographic setting of the population(s) sampled, base rates of diagnosis, country/region sampled and the diagnostic method that was used. Using this information, clinicians will be able to anchor the rate of GAD that they are likely to see in their clinical practice. * '''''To see prevalence rates across multiple disorders,''''' [[Evidence based assessment/Preparation phase#Base rates for transdiagnostic comparison|'''''click here.''''']] {| class="wikitable sortable" border="1" |- ! Demography ! Setting ! Base Rate ! Diagnostic Method |- | Adults and adolescences in all of U.S.A. | US National Comorbidity Survey Replication (NCS-R; age > = 13) [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4005415/pdf/nihms-571992.pdf (2012)]<ref name="KesslerEtAl2012" /> |0.9% (age 13-17) 2.9% (age 18-64) 1.2% (age &gt;= 65) 2.0% (age &gt;=13) | Fully-structured Composite International Diagnostic Interview (CIDI Version 3.0) |- | Psychiatric outpatients | Individuals seeking treatment in a Psychiatric Outpatient Clinic (age range not reported) ([https://ajp.psychiatryonline.org/doi/pdf/10.1176/appi.ajp.162.10.1911 2014])<ref name="ZimmermanEtAl2005" /> |21% | Structured Clinical Interview for DSM-IV (SCID) |- | Caucasian youth | Children seeking treatment in a Child &amp; Adolescent Anxiety Diagnostic Clinic (age 7 – 18 years old) ([http://journals.sagepub.com/doi/pdf/10.1177/1073191110375792 2011])<ref name="BrownJacobsenEtAl2011" /> |0.39% (parent report) 0.38% (child report) | Anxiety Disorders Interview Schedule for Children for DSM-IV Spence Children's Anxiety Scale (SCAS) |- | Caucasian, African American, Asian American, and Hispanic population | Collaborative Psychiatric Epidemiology Studies (CPES; age &gt;= 18, data merged from three representative national database) ([https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3135672/pdf/nihms281333.pdf 2011])<ref>{{Cite journal|last=McLean|first=Carmen P.|last2=Asnaani|first2=Anu|last3=Litz|first3=Brett T.|last4=Hofmann|first4=Stefan G.|date=2011-08-01|title=Gender differences in anxiety disorders: Prevalence, course of illness, comorbidity and burden of illness|url=https://www.sciencedirect.com/science/article/pii/S0022395611000458|journal=Journal of Psychiatric Research|language=en|volume=45|issue=8|pages=1027–1035|doi=10.1016/j.jpsychires.2011.03.006|issn=0022-3956|pmc=PMC3135672|pmid=21439576}}</ref> |4.1% (female) 2.1% (male) | World Mental Health Survey Initiative Version of the World Health Organization Composite International Interview (WMH-CIDI) |- | Pennsylvania | Metropolitan Community Sample, all individuals with eating disorders (ages 13 – 65) ([https://ajp.psychiatryonline.org/doi/pdf/10.1176/appi.ajp.161.12.2215 2014])<ref name="KayeEtAl2004" /> |10% | Structured Clinical Interview for DSM-IV (SCID) |- | Adolescents in all of U.S.A. | National Comorbidity Survey Replication Adolescent Supplement (NCS-A; ages 3–18 in the continental U.S) ([https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2946114/pdf/nihms214371.pdf 2011])<ref name="MerikangasEtAl2010" /> |2.2% | World Health Organization Composite International Diagnostic Interview (WHO-CIDI) |- |Adolescents in all of U.S.A |National Comorbidity Survey Replication Adolescent Supplement (NCS-A; ages 3–18 in the continental U.S)<ref name=":3">Kessler, R. C., Avenevoli, S., Costello, E. J., Georgiades, K., Green, J. G., Gruber, M. J., . . . Merikangas, K. R. (2012). Prevalence, persistence, and sociodemographic correlates of DSM-IV disorders in the National Comorbidity Survey Replication Adolescent Supplement. Archives of General Psychiatry, 69(4), 372-380. doi:10.1001/archgenpsychiatry.2011.160</ref> |5.4% |Composite International Diagnostic Interview (CIDI) |- | North Carolina | Rural community sample African American and White youth (ages 13-16) [https://www.ncbi.nlm.nih.gov/pubmed/12365876 (2002)]<ref>{{Cite journal|last=Angold|first=Adrian|last2=Erkanli|first2=Alaattin|last3=Farmer|first3=Elizabeth M. Z.|last4=Fairbank|first4=John A.|last5=Burns|first5=Barbara J.|last6=Keeler|first6=Gordon|last7=Costello|first7=E. Jane|date=October 2002|title=Psychiatric disorder, impairment, and service use in rural African American and white youth|url=https://www.ncbi.nlm.nih.gov/pubmed/12365876|journal=Archives of General Psychiatry|volume=59|issue=10|pages=893–901|issn=0003-990X|pmid=12365876}}</ref> |1.4% | The Child and Adolescent Psychiatric Assessment (CAPA) |- | Texas | Metropolitan Community Sample (ages 11-17) ([https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2736593/pdf/nihms30019.pdf 2007])<ref name="RobertsEtAl2007" /> |0.4% | Diagnostic Interview Schedule for Children, Version IV (DISC-IV) |- | Midwestern Urban | Incarcerated adolescents (ages 10-18)<ref>{{Cite journal|last=ABRAM|first=KAREN M.|last2=CHOE|first2=JEANNE Y.|last3=WASHBURN|first3=JASON J.|last4=TEPLIN|first4=LINDA A.|last5=KING|first5=DEVON C.|last6=DULCAN|first6=MINA K.|title=Suicidal Ideation and Behaviors Among Youths in Juvenile Detention|url=http://linkinghub.elsevier.com/retrieve/pii/S0890856709623121|journal=Journal of the American Academy of Child & Adolescent Psychiatry|volume=47|issue=3|pages=291–300|doi=10.1097/chi.0b013e318160b3ce}}</ref> [http://vb3lk7eb4t.search.serialssolutions.com/?ctx_ver=Z39.88-2004&ctx_enc=info%3Aofi%2Fenc%3AUTF-8&rfr_id=info%3Asid%2Fsummon.serialssolutions.com&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=Suicidal+Ideation+and+Behaviors+Among+Youths+in+Juvenile+Detention&rft.jtitle=Journal+of+the+American+Academy+of+Child+%26+Adolescent+Psychiatry&rft.au=ABRAM%2C+KAREN+M.%2C+Ph.D&rft.au=CHOE%2C+JEANNE+Y.%2C+B.A&rft.au=WASHBURN%2C+JASON+J.%2C+Ph.D.%2C+A.B.P.P&rft.au=TEPLIN%2C+LINDA+A.%2C+Ph.D&rft.date=2008&rft.issn=0890-8567&rft.eissn=1527-5418&rft.volume=47&rft.issue=3&rft.spage=291&rft.epage=300&rft_id=info:doi/10.1097%2FCHI.0b013e318160b3ce&rft.externalDocID=1_s2_0_S0890856709623121 (2002)] |1% | Diagnostic Interview Schedule for Children, Version IV (DISC-IV) |- |Non-institutionalized general US population |LGBTQ sample (ages 20-65)<ref>{{Cite journal|last=Bostwick|first=Wendy B.|last2=Boyd|first2=Carol J.|last3=Hughes|first3=Tonda L.|last4=McCabe|first4=Sean Esteban|date=2010-3|title=Dimensions of Sexual Orientation and the Prevalence of Mood and Anxiety Disorders in the United States|url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2820045/|journal=American Journal of Public Health|volume=100|issue=3|pages=468–475|doi=10.2105/AJPH.2008.152942|issn=0090-0036|pmc=PMC2820045|pmid=19696380}}</ref> [http://ajph.aphapublications.org/doi/10.2105/AJPH.2008.152942 (2013)] |Women: 14.8% same-sex 22.5% bisexual Men: 16.9% same-sex 11.5% bisexual |The Alcohol Use Disorder and Associated Disabilities Interview Schedule-IV (AUDADIS-IV) |- |Non-institutionalized general US population |Cross-ethnic American population (ages 18+)<ref>{{Cite journal|last=Asnaani|first=Anu|last2=Richey|first2=J. Anthony|last3=Dimaite|first3=Ruta|last4=Hinton|first4=Devon E.|last5=Hofmann|first5=Stefan G.|date=2010-8|title=A Cross-Ethnic Comparison of Lifetime Prevalence Rates of Anxiety Disorders|url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2931265/|journal=The Journal of nervous and mental disease|volume=198|issue=8|pages=551–555|doi=10.1097/NMD.0b013e3181ea169f|issn=0022-3018|pmc=PMC2931265|pmid=20699719}}</ref> [https://journals.lww.com/jonmd/Abstract/2010/08000/A_Cross_Ethnic_Comparison_of_Lifetime_Prevalence.4.aspx (2018)] |White 8.6% African Americans 4.9% Hispanic Americans 5.8% Asian Americans 2.4% |World Mental Health Survey Initiative Version of the World Health Organization Composite International Interview (WMH-CIDI) |- |Outpatient clinics worldwide |Samples across multiple studies worldwide (all ages)<ref name=":12">{{Cite journal|last=Rettew|first=David C.|last2=Lynch|first2=Alicia Doyle|last3=Achenbach|first3=Thomas M.|last4=Dumenci|first4=Levent|last5=Ivanova|first5=Masha Y.|date=2009-09|title=Meta-analyses of agreement between diagnoses made from clinical evaluations and standardized diagnostic interviews|url=http://dx.doi.org/10.1002/mpr.289|journal=International Journal of Methods in Psychiatric Research|language=en|volume=18|issue=3|pages=169–184|doi=10.1002/mpr.289|issn=1049-8931}}</ref> |5% |Clinical evaluations |- |Outpatient clinic worldwide |Samples across multiple studies worldwide (all ages)<ref name=":12" /> |10% |Standardized Diagnostic Interviews (SDIs) |- |People during pregnancy and postpartum |Samples across multiple studies worldwide<ref>{{Cite journal|last=Fawcett|first=Emily J.|last2=Fairbrother|first2=Nichole|last3=Cox|first3=Megan L.|last4=White|first4=Ian R.|last5=Fawcett|first5=Jonathan M.|date=2019-07-23|title=The Prevalence of Anxiety Disorders During Pregnancy and the Postpartum Period: A Multivariate Bayesian Meta-Analysis|url=https://www.psychiatrist.com/JCP/article/Pages/2019/v80/18r12527.aspx|journal=The Journal of Clinical Psychiatry|volume=80|issue=4|doi=10.4088/JCP.18r12527|issn=1555-2101|pmc=PMC6839961|pmid=31347796}}</ref> |2.4% |Standardized Diagnostic Interviews (SDIs) |- |Older adults |Samples across in Switzerland, German, Italy, England, Spain, and Israel |3.7% (age 65-69) 3.7% (age 70-74) 2.6% (age 75-79) 2.0% (age >80) |Clinical evaluations |} '''Search terms:''' [General Anxiety Disorder] AND [prevalence OR incidence] in GoogleScholar and PsycINFO == [[Evidence based assessment/Prediction phase|'''Prediction phase''']] == === Psychometric properties of screening instruments for GAD === The following section contains a list of screening and diagnostic instruments for generalized anxiety disorder. The section includes administration information, psychometric data, and PDFs or links to the screenings. * Screenings are used as part of the [[Evidence based assessment/Prediction phase|prediction phase]] of assessment; for more information on interpretation of this data, or how screenings fit in to the assessment process, click [[Evidence based assessment/Prediction phase|here]]. * '''''For a list of more broadly reaching screening instruments, [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prediction_phase&wteswitched=1#Psychometric_properties_of_common_screening_instruments click here.]''''' {| class="wikitable sortable" border="1" ! colspan="5" |Screening measures for GAD |- ! Measure ! Format (Reporter) ! Age Range ! Administration/ Completion Time ! style="width:12em" | Where to Access |- | Penn State Worry Questionnaire (PSWQ)<ref name=":0">{{Cite book|url=https://www.worldcat.org/oclc/314222270|title=A guide to assessments that work|date=2008|publisher=Oxford University Press|author=Hunsley, John |author2=Mash, Eric J.|isbn=9780195310641|location=New York|oclc=314222270}}</ref> | Questionnaire (Adult Version, Child Version) | 18+ (Adult Version), 6-18 (Child Version) | 4 minutes |[http://www.midss.org/content/penn-state-worry-questionnaire-pswq PSWQ homepage] [https://mfr.osf.io/render?url=https://osf.io/s7p38/?action=download%26mode=render PSWQ Adult Version] [https://mfr.osf.io/render?url=https://osf.io/6q8y9/?action=download%26mode=render PSWQ Child Version] [https://mfr.osf.io/render?url=https://osf.io/gx5sr/?action=download%26mode=render PSWC-C Korean] [https://mfr.osf.io/render?url=https://osf.io/hc6n2/?action=download%26mode=render PSWQ-C Danish] [https://mfr.osf.io/render?url=https://osf.io/fwbes/?action=download%26mode=render Scoring the PSWQ-C] |- |[[wikipedia:Screen_for_child_anxiety_related_disorders|Screen for Child Anxiety Related Emotional Disorder (SCARED)]]<ref name=":0" /> | Questionnaire (Child, Parent) | 8-19 | 9 or 16 minutes |[http://www.midss.org/content/screen-child-anxiety-related-disorders-scared SCARED] homepage [[wikipedia:Screen_for_child_anxiety_related_disorders#PDFs_and_automated_scoring_for_SCARED|SCARED English + Translations & Automatic Scoring]] |- |Child Behavior Checklist (CBCL)<ref name=":0" /> |Questionnaire (Parent report) |6-18 |10 minutes |[https://aseba.org/ ASEBA homepage][https://store.aseba.org/ Purchase] |} === Likelihood ratios and AUCs of screening instruments for GAD === * '''''For a list of the likelihood ratios for more broadly reaching screening instruments, [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prediction_phase&wteswitched=1#Likelihood_ratios_and_AUCs_of_common_screening_instruments click here.]''''' {| class="wikitable sortable" border="1" ! Screening Measure (Primary Reference) ! Area Under Curve (AUC) ! LR+ (Score) ! LR- (Score) ! Clinical Generalizability !Where to Access |- | Penn State Worry Questionnaire (PSWQ)<ref name=":2">{{Cite journal|last=Fresco|first=David M.|last2=Mennin|first2=Douglas S.|last3=Heimberg|first3=Richard G.|last4=Turk|first4=Cynthia L.|title=Using the Penn State Worry Questionnaire to identify individuals with generalized anxiety disorder: a receiver operating characteristic analysis|url=http://linkinghub.elsevier.com/retrieve/pii/S0005791603000569|journal=Journal of Behavior Therapy and Experimental Psychiatry|volume=34|issue=3-4|pages=283–291|doi=10.1016/j.jbtep.2003.09.001}}</ref> | 0.74 (N=164) | 1.8 (65+) | 0.5 (< 65) | Generalized Anxiety Disorder vs. social anxiety disorder, adults presenting to specialty anxiety clinic |[https://mfr.osf.io/render?url=https://osf.io/s7p38/?action=download%26mode=render PSWQ Adult Version] [https://mfr.osf.io/render?url=https://osf.io/6q8y9/?action=download%26mode=render PSWQ Child Version] |- |[[wikipedia:Screen_for_child_anxiety_related_disorders#PDFs_and_automated_scoring_for_SCARED|Screen for Child Anxiety Related Disorders (SCARED)]]<ref name="BirmaherEtAl1997" /> | .70 (N=243) | 5.0 (+32) | .04 | High: Pure anxiety disorder versus non-anxiety psychiatric disorder, excluding children with disruptive disorder and depression |[http://www.midss.org/content/penn-state-worry-questionnaire-pswq SCARED English + Translations & Automatic Scoring] |- |CBCL Anxious/Depressed Scale T-score<ref>{{Cite journal|last=Eimecke|first=Sylvia D.|last2=Remschmidt|first2=Helmut|last3=Mattejat|first3=Fritz|date=2011-03|title=Utility of the Child Behavior Checklist in screening depressive disorders within clinical samples|url=https://linkinghub.elsevier.com/retrieve/pii/S0165032710005458|journal=Journal of Affective Disorders|language=en|volume=129|issue=1-3|pages=191–197|doi=10.1016/j.jad.2010.08.011}}</ref> |.75 (N = 1445) |1.49 (9+) |.67(9-) |Inpatient and outpatient children and adolescents |[https://store.aseba.org/ Purchase] |} '''Note:''' “LR+” refers to the change in likelihood ratio associated with a positive test score, and “LR-” is the likelihood ratio for a low score. Likelihood ratios of 1 indicate that the test result did not change impressions at all. LRs larger than 10 or smaller than .10 are frequently clinically decisive; 5 or .20 are helpful, and between 2.0 and .5 are small enough that they rarely result in clinically meaningful changes of formulation<ref>Sackett, D. L., Straus, S. E., Richardson, W. S., Rosenberg, W., & Haynes, R. B. (2000). Evidence-based medicine: How to practice and teach EBM. Edinburgh: Churchill Livingstone.</ref>. '''Search terms:''' [General Anxiety Disorder] AND [children OR adolescents OR pediatric] AND [sensitivity OR specificity] in GoogleScholar and PsycINFO === Interpreting depression screening measure scores === * For information on interpreting screening measure scores, click [[Evidence based assessment/Prediction phase#Interpreting screening measure scores|here.]] ==[[Evidence based assessment/Prescription phase|'''Prescription phase''']]== ===Gold standard diagnostic interviews=== * For a list of broad reaching diagnostic interviews sortable by disorder with PDFs (if applicable), [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prescription_phase&wteswitched=1#Common_Diagnostic_Interviews click here.] === Recommended diagnostic instruments for GAD === {| class="wikitable sortable" ! colspan="5" |Diagnostic instruments for GAD |- !Measure !Format (Reporter) !Age Range !Administration/ Completion Time !Where to Access |- |Anxiety Disorders Interview Schedule for Children/Parent<ref name=":1">{{Cite journal|date=2001-08-01|title=Test-Retest Reliability of Anxiety Symptoms and Diagnoses With the Anxiety Disorders Interview Schedule for DSM-IV: Child and Parent Versions|url=https://www.sciencedirect.com/science/article/pii/S0890856709603427|journal=Journal of the American Academy of Child & Adolescent Psychiatry|language=en|volume=40|issue=8|pages=937–944|doi=10.1097/00004583-200108000-00016|issn=0890-8567}}</ref> |Structured Interview (Child (ADIS-C), Parent (ADIS-P)) |6-16<ref>{{Cite journal|last=LYNEHAM|first=HEIDI J.|last2=ABBOTT|first2=MAREE J.|last3=RAPEE|first3=RONALD M.|date=2007-06|title=Interrater Reliability of the Anxiety Disorders Interview Schedule for DSM-IV: Child and Parent Version|url=https://doi.org/10.1097/chi.0b013e3180465a09|journal=Journal of the American Academy of Child &amp; Adolescent Psychiatry|volume=46|issue=6|pages=731–736|doi=10.1097/chi.0b013e3180465a09|issn=0890-8567}}</ref> |Varies |[https://books.google.com/books/about/Anxiety_Disorders_Interview_Schedule_for.html?id=xpR6V3rboxwC Purchase] |- |Anxiety and Related Disorders Interview Schedule for DSM-5 (ADIS-5)<ref name=":0" /> |Structured Interview (Adult) |16+ |Varies |[https://global.oup.com/academic/product/anxiety-and-related-disorders-interview-schedule-for-dsm-5-adis-5---adult-version-9780199325160?cc=us&lang=en& Purchase] |- |Structured Clinical Interview for DSM-5-Clinician Version (SCID-5-CV)<ref>{{Cite journal|last=Shabani|first=Amir|last2=Masoumian|first2=Samira|last3=Zamirinejad|first3=Somayeh|last4=Hejri|first4=Maryam|last5=Pirmorad|first5=Tahereh|last6=Yaghmaeezadeh|first6=Hooman|date=2021-05|title=Psychometric properties of Structured Clinical Interview for DSM‐5 Disorders‐Clinician Version (SCID‐5‐CV)|url=https://onlinelibrary.wiley.com/doi/10.1002/brb3.1894|journal=Brain and Behavior|language=en|volume=11|issue=5|doi=10.1002/brb3.1894|issn=2162-3279|pmc=PMC8119811|pmid=33729681}}</ref> |Structured Interview (Adult ) |16+ |Varies |[https://www.columbiapsychiatry.org/research/research-labs/diagnostic-and-assessment-lab/structured-clinical-interview-dsm-disorders-11 Website and purchase] |- |Generalized Anxiety Disorder Screener (GAD-7)<ref name=":0" /> |Questionnaire (Self-report) |18+ |5 minutes |[https://www.pfizerpcoa.com/general-anxiety-disorder-7-gad-7-screener GAD-7 homepage] [https://osf.io/szmpu GAD-7 PDF] |} ==[[Evidence based assessment/Process phase|'''Process phase''']]== The following section contains a list of process and outcome measures for generalized anxiety disorder. The section includes benchmarks based on published norms for several outcome and severity measures, as well as information about commonly used process measures. Process and outcome measures are used as part of the [[Evidence based assessment/Process phase|process phase]] of assessment. For more information of differences between process and outcome measures, see the page on the [[Evidence based assessment/Process phase|process phase of assessment]]. === Process measures === === Outcome and severity measures === * This table includes clinically significant benchmarks for '''(insert portfolio name here)''' specific outcome measures * Information on how to interpret this table can be [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Process_phase found here]. * Additionally, these [[Evidence based assessment/Vignettes|vignettes]] might be helpful resources for understanding appropriate adaptation of outcome measures in practice. *''<u>For clinically significant change benchmarks for the CBCL, YSR, and TRF total, externalizing, internalizing, and attention benchmarks,</u>'' [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Process_phase&wteswitched=1#Clinically_significant_change_benchmarks_for_widely-used_outcome_measures see here.] {| class="wikitable sortable" border="1" | colspan="7" |'''Clinically significant change benchmarks with common instruments for GAD''' |- | rowspan=1" style="text-align:center;font-size:130%;" | <b> Measure</b> | colspan="3" style="text-align:center;font-size:130%" width="300" | <b> Cut-off scores</b> | colspan="3" style="text-align:center;font-size:120%" | <b> Critical Change <br> (unstandardized scores)</b> |- | colspan="7" span style="font-size:110%; text-align:center;" | <b> Benchmarks Based on Published Norms</b> |- | colspan="1" | | style="text-align:center;font-size:110%" | <b> A</b> | style="text-align:center;font-size:110%" | <b> B</b> | style="text-align:center;font-size:110%" | <b> C</b> | style="text-align:center;font-size:110%" | <b> 95%</b> | style="text-align:center;font-size:110%" | <b> 90%</b> | style="text-align:center;font-size:110%" | <b> SE_difference</b> |- | rowspan="1" style="text-align:center;" | <b> GAD-7</b> | style=“text-align:center;”| -1 | style=“text-align:center;”| 1.3 | style=“text-align:center;”| 0.5 | style=“text-align:center;”| 0.6 | style=“text-align:center;”| 0.5 | style=“text-align:center;”| 0.3 |- | rowspan="1" style="text-align:center;" | <b> PSWQ</b> | style=“text-align:center;”| 51 | style=“text-align:center;”| 73 | style=“text-align:center;”| 59 | style=“text-align:center;”| 9 | style=“text-align:center;”| 8 | style=“text-align:center;”| 4.8 |- | rowspan="1" style="text-align:center;" | <b> SCARED </b> | style=“text-align:center;”| 9.9 | style=“text-align:center;”| 18.1 | style=“text-align:center;”| 15.3 | style=“text-align:center;”| 8.9 | style=“text-align:center;”| 7.5 | style=“text-align:center;”| 4.5 |} '''Note:''' “A” = Away from the clinical range, “B” = Back into the nonclinical range, “C” = Closer to the nonclinical than clinical mean. '''Search terms:''' [General Anxiety Disorder] AND [children OR adolescents OR pediatric] AND [clinical significance OR outcomes] in GoogleScholar and PsycINFO === Treatment === {{collapse top| Click here for treatment information}} Individuals suffering from GAD tend to be high users of outpatient medical care. When treating GAD, physicians should first determine whether pharmacotherapy, psychotherapy, or a combination of the two treatments would be most beneficial to the patient. Literature suggests that treatment of GAD frequently consists of a combination of psychotherapy and pharmacotherapy. Although these therapies have the potential to be effective individually, previous work demonstrates that when combined the degree of clinically significant change increases significantly. Recent studies (e.g., Gorman, 2003<ref name="Gorman2003" />; Walkup et al., 2008<ref name="WalkupEtAl2008" />) have provided evidence to support this claim with the most efficacious medication and behavioral interventions listed below. # '''Medication Interventions''' ## ''Sertraline (Zoloft)'' has been shown to reduce experiences and effects of GAD above and beyond that of placebo conditions. ## ''Pregabalin.'' The mean baseline-to-endpoint decreases in total Hamilton anxiety scale score in the patients given 150 mg/day of pregabalin (–9.2) was significantly greater than the decrease in those given placebo (–6.8)<ref name="PandeEtAl2003" />. ## ''Paroxetine.'' Remission was achieved by 30% of patients in the 20-mg paroxetine groups compared with 20% given placebo. For all three domains of the Sheehan Disability Scale, significantly greater improvement was seen with paroxetine than placebo<ref name="RickelsEtAl2003" />. # '''Behavioral interventions''' ## ''Cognitive behavioral therapy.'' Fourteen 60-minute sessions, which include CBT in anxiety-management skills, followed by behavioral exposure to anxiety-provoking situations have been shown to be effective in treating GAD. A review of studies by Fisher and Durham (1999)<ref name="FisherEtAl1999" /> revealed significant recovery rates at a 6 month follow up after CBT. ## ''Exposure therapy and modeling therapy.'' One meta-analysis found that virtual reality exposure therapy for anxiety disorders had a large effect size (Cohen's d=1.11) compared to controls.<ref>{{Cite journal|last=Powers|first=Mark B.|last2=Emmelkamp|first2=Paul M.G.|title=Virtual reality exposure therapy for anxiety disorders: A meta-analysis|url=https://doi.org/10.1016/j.janxdis.2007.04.006|journal=Journal of Anxiety Disorders|volume=22|issue=3|pages=561–569|doi=10.1016/j.janxdis.2007.04.006}}</ref> ## ''Mindfulness meditation.'' New treatment options such as mindfulness meditation-based stress reduction interventions have also shown to reduce symptoms over the long-term.<ref>{{Cite journal|last=Miller|first=J. J.|last2=Fletcher|first2=K.|last3=Kabat-Zinn|first3=J.|date=May 1995|title=Three-year follow-up and clinical implications of a mindfulness meditation-based stress reduction intervention in the treatment of anxiety disorders|url=https://www.ncbi.nlm.nih.gov/pubmed/7649463|journal=General Hospital Psychiatry|volume=17|issue=3|pages=192–200|issn=0163-8343|pmid=7649463}}</ref> # '''Combination treatment''' ## Previous research suggests that combination therapy that includes components of psychotherapy and pharmacotherapy are the most efficacious in treating GAD. In a study comparing the efficacies GAD treatments, Walkup and colleagues demonstrated a 21-25% improvement of combination therapy over cognitive behavioral therapy or sertraline alone during short-term treatment. These findings suggest that among effective treatments, combination therapy has the potential to provide the best chance for a positive outcome. See Gorman, 2003<ref name="Gorman2003" />; Walkup et al., 2008<ref name="WalkupEtAl2008" />. {{collapse bottom}} * Please refer to the page on [[wikipedia:Generalized_anxiety_disorder|generalized anxiety disorder]] for more information on available treatment or go to [http://effectivechildtherapy.org/concerns-symptoms-disorders/disorders/fear-worry-and-anxiety/ Effective Child Therapy] for a curated resource on effective treatments for GAD. *For information on conducting Exposure Therapy for anxiety disordered youth, see [https://www.bravepracticeforkids.com/ www.BravePracticeForKids.com] =='''External Resources'''== # [http://apps.who.int/classifications/icd10/browse/2010/en#/F41.1 ICD-10 diagnostic criteria] # [https://en.wikiversity.org/w/index.php?title=Helping_Give_Away_Psychological_Science/Resources/Annotated_List_of_Where_and_How_to_Find_a_Therapist&wteswitched=1#Other_low-cost_options Find-a-Therapist] #*This is a curated list of find-a-therapist websites where you can find a provider # [https://www.nimh.nih.gov/health/topics/anxiety-disorders/index.shtml NIMH] entry about anxiety disorders # OMIM (Online Mendelian Inheritance in Man) #*[https://www.omim.org/entry/607834 607834] # [https://emedicine.medscape.com/article/286227-overview#a2 eMedicine entry about anxiety disorders] #[https://sccap53.org Society of Clinical Child and Adolescent Psychology] #[http://effectivechildtherapy.org/concerns-symptoms-disorders/disorders/fear-worry-and-anxiety/ Effective Child Therapy information on Fear, Worry, & Anxiety] #*Effective Child Therapy is website sponsored by Division 53 of the American Psychological Association (APA), or The [https://sccap53.org Society of Clinical Child and Adolescent Psychology] (SCCAP), in collaboration with the Association for Behavioral and Cognitive Therapies (ABCT). Use for information on symptoms and available treatments. #[http://pediatricbipolar.pitt.edu/resources/instruments Links to SCARED Child, Parent, and Adult + Translations] =='''References'''== {{collapse top|Click here for references}} {{Reflist|3|refs= <ref name="BirmaherEtAl1997">{{cite journal|last1=Birmaher|first1=B|last2=Khetarpal|first2=S|last3=Brent|first3=D|last4=Cully|first4=M|last5=Balach|first5=L|last6=Kaufman|first6=J|last7=Neer|first7=SM|title=The Screen for Child Anxiety Related Emotional Disorders (SCARED): scale construction and psychometric characteristics.|journal=Journal of the American Academy of Child and Adolescent Psychiatry|date=April 1997|volume=36|issue=4|pages=545-53|pmid=9100430}}</ref> <ref name="BrownJacobsenEtAl2011">{{cite journal|last1=Brown-Jacobsen|first1=AM|last2=Wallace|first2=DP|last3=Whiteside|first3=SP|title=Multimethod, multi-informant agreement, and positive predictive value in the identification of child anxiety disorders using the SCAS and ADIS-C.|journal=Assessment|date=September 2011|volume=18|issue=3|pages=382-92|pmid=20644080}}</ref> <ref name="CostelloEtAl1996">{{cite journal|last1=Costello|first1=EJ|last2=Angold|first2=A|last3=Burns|first3=BJ|last4=Stangl|first4=DK|last5=Tweed|first5=DL|last6=Erkanli|first6=A|last7=Worthman|first7=CM|title=The Great Smoky Mountains Study of Youth. Goals, design, methods, and the prevalence of DSM-III-R disorders.|journal=Archives of general psychiatry|date=December 1996|volume=53|issue=12|pages=1129-36|pmid=8956679}}</ref> <ref name="ChorpitaEtAl2000">{{cite journal|last1=Chorpita|first1=BF|last2=Yim|first2=L|last3=Moffitt|first3=C|last4=Umemoto|first4=LA|last5=Francis|first5=SE|title=Assessment of symptoms of DSM-IV anxiety and depression in children: a revised child anxiety and depression scale.|journal=Behaviour research and therapy|date=August 2000|volume=38|issue=8|pages=835-55|pmid=10937431}}</ref> <ref name="ChorpitaEtAl2005">{{cite journal|last1=Chorpita|first1=BF|last2=Moffitt|first2=CE|last3=Gray|first3=J|title=Psychometric properties of the Revised Child Anxiety and Depression Scale in a clinical sample.|journal=Behaviour research and therapy|date=March 2005|volume=43|issue=3|pages=309-22|pmid=15680928}}</ref> <ref name="FisherEtAl1999">{{cite journal|last1=Fisher|first1=PL|last2=Durham|first2=RC|title=Recovery rates in generalized anxiety disorder following psychological therapy: an analysis of clinically significant change in the STAI-T across outcome studies since 1990.|journal=Psychological medicine|date=November 1999|volume=29|issue=6|pages=1425-34|pmid=10616949}}</ref> <ref name="Gorman2003">{{cite journal|last1=Gorman|first1=JM|title=Treating generalized anxiety disorder.|journal=The Journal of clinical psychiatry|date=2003|volume=64 Suppl 2|pages=24-9|pmid=12625796}}</ref> <ref name="HaleEtAl2014">{{cite journal|last1=Hale III|first1=WW|last2=Raaijmakers|first2=QA|last3=van Hoof|first3=A|last4=Meeus|first4=WH|title=Improving Screening Cut-Off Scores for DSM-5 Adolescent Anxiety Disorder Symptom Dimensions with the Screen for Child Anxiety Related Emotional Disorders.|journal=Psychiatry journal|date=2014|volume=2014|pages=517527|pmid=24829901}}</ref> <ref name="KayeEtAl2004">{{cite journal|last1=Kaye|first1=WH|last2=Bulik|first2=CM|last3=Thornton|first3=L|last4=Barbarich|first4=N|last5=Masters|first5=K|title=Comorbidity of anxiety disorders with anorexia and bulimia nervosa.|journal=The American journal of psychiatry|date=December 2004|volume=161|issue=12|pages=2215-21|pmid=15569892}}</ref> <ref name="KesslerEtAl2012">{{cite journal|last1=Kessler|first1=RC|last2=Petukhova|first2=M|last3=Sampson|first3=NA|last4=Zaslavsky|first4=AM|last5=Wittchen H|first5=-U|title=Twelve-month and lifetime prevalence and lifetime morbid risk of anxiety and mood disorders in the United States.|journal=International journal of methods in psychiatric research|date=September 2012|volume=21|issue=3|pages=169-84|pmid=22865617}}</ref> <ref name="LynehamEtAl2007">{{cite journal|last1=Lyneham|first1=HJ|last2=Abbott|first2=MJ|last3=Rapee|first3=RM|title=Interrater reliability of the Anxiety Disorders Interview Schedule for DSM-IV: child and parent version.|journal=Journal of the American Academy of Child and Adolescent Psychiatry|date=June 2007|volume=46|issue=6|pages=731-6|pmid=17513985}}</ref> <ref name="MarchEtAl1997">{{cite journal|last1=March|first1=JS|last2=Parker|first2=JD|last3=Sullivan|first3=K|last4=Stallings|first4=P|last5=Conners|first5=CK|title=The Multidimensional Anxiety Scale for Children (MASC): factor structure, reliability, and validity.|journal=Journal of the American Academy of Child and Adolescent Psychiatry|date=April 1997|volume=36|issue=4|pages=554-65|pmid=9100431}}</ref> <ref name="McLeanEtAl2011">{{cite journal|last1=McLean|first1=CP|last2=Asnaani|first2=A|last3=Litz|first3=BT|last4=Hofmann|first4=SG|title=Gender differences in anxiety disorders: prevalence, course of illness, comorbidity and burden of illness.|journal=Journal of psychiatric research|date=August 2011|volume=45|issue=8|pages=1027-35|pmid=21439576}}</ref> <ref name="MerikangasEtAl2010">{{cite journal|last1=Merikangas|first1=KR|last2=He|first2=JP|last3=Burstein|first3=M|last4=Swanson|first4=SA|last5=Avenevoli|first5=S|last6=Cui|first6=L|last7=Benjet|first7=C|last8=Georgiades|first8=K|last9=Swendsen|first9=J|title=Lifetime prevalence of mental disorders in U.S. adolescents: results from the National Comorbidity Survey Replication--Adolescent Supplement (NCS-A).|journal=Journal of the American Academy of Child and Adolescent Psychiatry|date=October 2010|volume=49|issue=10|pages=980-9|pmid=20855043}}</ref> <ref name="PandeEtAl2003">{{cite journal|last1=Pande|first1=AC|last2=Crockatt|first2=JG|last3=Feltner|first3=DE|last4=Janney|first4=CA|last5=Smith|first5=WT|last6=Weisler|first6=R|last7=Londborg|first7=PD|last8=Bielski|first8=RJ|last9=Zimbroff|first9=DL|last10=Davidson|first10=JR|last11=Liu-Dumaw|first11=M|title=Pregabalin in generalized anxiety disorder: a placebo-controlled trial.|journal=The American journal of psychiatry|date=March 2003|volume=160|issue=3|pages=533-40|pmid=12611835}}</ref> <ref name="RickelsEtAl2003">{{cite journal|last1=Rickels|first1=K|last2=Zaninelli|first2=R|last3=McCafferty|first3=J|last4=Bellew|first4=K|last5=Iyengar|first5=M|last6=Sheehan|first6=D|title=Paroxetine treatment of generalized anxiety disorder: a double-blind, placebo-controlled study.|journal=The American journal of psychiatry|date=April 2003|volume=160|issue=4|pages=749-56|pmid=12668365}}</ref> <ref name="RobertsEtAl2007">{{cite journal|last1=Roberts|first1=RE|last2=Roberts|first2=CR|last3=Xing|first3=Y|title=Rates of DSM-IV psychiatric disorders among adolescents in a large metropolitan area.|journal=Journal of psychiatric research|date=December 2007|volume=41|issue=11|pages=959-67|pmid=17107689}}</ref> <ref name="SeligmanEtAl2004">{{cite journal|last1=Seligman|first1=LD|last2=Ollendick|first2=TH|last3=Langley|first3=AK|last4=Baldacci|first4=HB|title=The utility of measures of child and adolescent anxiety: a meta-analytic review of the Revised Children's Manifest Anxiety Scale, the State-Trait Anxiety Inventory for Children, and the Child Behavior Checklist.|journal=Journal of clinical child and adolescent psychology : the official journal for the Society of Clinical Child and Adolescent Psychology, American Psychological Association, Division 53|date=September 2004|volume=33|issue=3|pages=557-65|pmid=15271613}}</ref> <ref name="WalkupEtAl2008">{{cite journal|last1=Walkup|first1=JT|last2=Albano|first2=AM|last3=Piacentini|first3=J|last4=Birmaher|first4=B|last5=Compton|first5=SN|last6=Sherrill|first6=JT|last7=Ginsburg|first7=GS|last8=Rynn|first8=MA|last9=McCracken|first9=J|last10=Waslick|first10=B|last11=Iyengar|first11=S|last12=March|first12=JS|last13=Kendall|first13=PC|title=Cognitive behavioral therapy, sertraline, or a combination in childhood anxiety.|journal=The New England journal of medicine|date=25 December 2008|volume=359|issue=26|pages=2753-66|pmid=18974308}}</ref> <ref name="WhitakerEtAl1990">{{cite journal|last1=Whitaker|first1=A|last2=Johnson|first2=J|last3=Shaffer|first3=D|last4=Rapoport|first4=JL|last5=Kalikow|first5=K|last6=Walsh|first6=BT|last7=Davies|first7=M|last8=Braiman|first8=S|last9=Dolinsky|first9=A|title=Uncommon troubles in young people: prevalence estimates of selected psychiatric disorders in a nonreferred adolescent population.|journal=Archives of general psychiatry|date=May 1990|volume=47|issue=5|pages=487-96|pmid=2331210}}</ref> <ref name="SpitzerEtAl2006">{{cite journal|last1=Spitzer|first1=RL|last2=Kroenke|first2=K|last3=Williams|first3=JB|last4=Löwe|first4=B|title=A brief measure for assessing generalized anxiety disorder: the GAD-7.|journal=Archives of internal medicine|date=22 May 2006|volume=166|issue=10|pages=1092-7|pmid=16717171}}</ref> <ref name="vanGastelEtAl2008">{{cite journal|last1=van Gastel|first1=W|last2=Ferdinand|first2=RF|title=Screening capacity of the Multidimensional Anxiety Scale for Children (MASC) for DSM-IV anxiety disorders.|journal=Depression and anxiety|date=2008|volume=25|issue=12|pages=1046-52|pmid=18833579}}</ref> <ref name="WoodEtAl2002">{{cite journal|last1=Wood|first1=JJ|last2=Piacentini|first2=JC|last3=Bergman|first3=RL|last4=McCracken|first4=J|last5=Barrios|first5=V|title=Concurrent validity of the anxiety disorders section of the Anxiety Disorders Interview Schedule for DSM-IV: child and parent versions.|journal=Journal of clinical child and adolescent psychology : the official journal for the Society of Clinical Child and Adolescent Psychology, American Psychological Association, Division 53|date=September 2002|volume=31|issue=3|pages=335-42|pmid=12149971}}</ref> <ref name="ZimmermanEtAl2005">{{cite journal|last1=Zimmerman|first1=M|last2=Rothschild|first2=L|last3=Chelminski|first3=I|title=The prevalence of DSM-IV personality disorders in psychiatric outpatients.|journal=The American journal of psychiatry|date=October 2005|volume=162|issue=10|pages=1911-8|pmid=16199838}}</ref> }} {{collapse bottom|Click here for references}} [[Category:Psychological disorder portfolios|{{SUBPAGENAME}}]] fnx5yuy1aklla83yubyccvugdlkqkpl 2414010 2414009 2022-08-12T22:22:58Z Aherman012 2943941 /* Base rates of GAD in different clinical settings */ wikitext text/x-wiki <noinclude>{{Helping Give Away Psychological Science Banner}}</noinclude> {{medical disclaimer}} {{:{{BASEPAGENAME}}/Sidebar}} ==[[Evidence based assessment/Portfolio template/What is a "portfolio"|'''What is a "portfolio"?''']]== * For background information on what assessment portfolios are, click the link in the heading above. Want even 'more' information about this topic? There's an extended version of this page [[Evidence-based assessment/Generalized anxiety disorder (assessment portfolio)/extended version|here]]. ==[[Evidence based assessment/Preparation phase|'''Preparation phase''']]== === Diagnostic criteria for generalized anxiety disorder === {{blockquotetop}} <big>'''ICD-11 Diagnostic Criteria<ref>https://icd.who.int/browse11/l-m/en#/http://id.who.int/icd/entity/1712535455</ref>'''</big> *Generalised anxiety disorder is characterized by marked symptoms of anxiety that persist for at least several months, for more days than not, manifested by either general apprehension (i.e. ‘free-floating anxiety’) or excessive worry focused on multiple everyday events, most often concerning family, health, finances, and school or work, together with additional symptoms such as muscular tension or motor restlessness, sympathetic autonomic over-activity, subjective experience of nervousness, difficulty maintaining concentration, irritability, or sleep disturbance. The symptoms result in significant distress or significant impairment in personal, family, social, educational, occupational, or other important areas of functioning. The symptoms are not a manifestation of another health condition and are not due to the effects of a substance or medication on the central nervous system. '''Changes in DSM-5''' * The diagnostic criteria for generalized anxiety disorder changed slightly from DSM-IV-TR to DSM-5. Summaries are available [https://www.ncbi.nlm.nih.gov/books/NBK519712/table/ch3.t9/?report=objectonly here]. {{blockquotebottom}} === Base rates of GAD in different clinical settings === This section describes the demographic setting of the population(s) sampled, base rates of diagnosis, country/region sampled and the diagnostic method that was used. Using this information, clinicians will be able to anchor the rate of GAD that they are likely to see in their clinical practice. * '''''To see prevalence rates across multiple disorders,''''' [[Evidence based assessment/Preparation phase#Base rates for transdiagnostic comparison|'''''click here.''''']] {| class="wikitable sortable" border="1" |- ! Demography ! Setting ! Base Rate ! Diagnostic Method |- | Adults and adolescences in all of U.S.A. | US National Comorbidity Survey Replication (NCS-R; age > = 13) [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4005415/pdf/nihms-571992.pdf (2012)]<ref name="KesslerEtAl2012" /> |0.9% (age 13-17) 2.9% (age 18-64) 1.2% (age &gt;= 65) 2.0% (age &gt;=13) | Fully-structured Composite International Diagnostic Interview (CIDI Version 3.0) |- | Psychiatric outpatients | Individuals seeking treatment in a Psychiatric Outpatient Clinic (age range not reported) ([https://ajp.psychiatryonline.org/doi/pdf/10.1176/appi.ajp.162.10.1911 2014])<ref name="ZimmermanEtAl2005" /> |21% | Structured Clinical Interview for DSM-IV (SCID) |- | Caucasian youth | Children seeking treatment in a Child &amp; Adolescent Anxiety Diagnostic Clinic (age 7 – 18 years old) ([http://journals.sagepub.com/doi/pdf/10.1177/1073191110375792 2011])<ref name="BrownJacobsenEtAl2011" /> |0.39% (parent report) 0.38% (child report) | Anxiety Disorders Interview Schedule for Children for DSM-IV Spence Children's Anxiety Scale (SCAS) |- | Caucasian, African American, Asian American, and Hispanic population | Collaborative Psychiatric Epidemiology Studies (CPES; age &gt;= 18, data merged from three representative national database) ([https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3135672/pdf/nihms281333.pdf 2011])<ref>{{Cite journal|last=McLean|first=Carmen P.|last2=Asnaani|first2=Anu|last3=Litz|first3=Brett T.|last4=Hofmann|first4=Stefan G.|date=2011-08-01|title=Gender differences in anxiety disorders: Prevalence, course of illness, comorbidity and burden of illness|url=https://www.sciencedirect.com/science/article/pii/S0022395611000458|journal=Journal of Psychiatric Research|language=en|volume=45|issue=8|pages=1027–1035|doi=10.1016/j.jpsychires.2011.03.006|issn=0022-3956|pmc=PMC3135672|pmid=21439576}}</ref> |4.1% (female) 2.1% (male) | World Mental Health Survey Initiative Version of the World Health Organization Composite International Interview (WMH-CIDI) |- | Pennsylvania | Metropolitan Community Sample, all individuals with eating disorders (ages 13 – 65) ([https://ajp.psychiatryonline.org/doi/pdf/10.1176/appi.ajp.161.12.2215 2014])<ref name="KayeEtAl2004" /> |10% | Structured Clinical Interview for DSM-IV (SCID) |- | Adolescents in all of U.S.A. | National Comorbidity Survey Replication Adolescent Supplement (NCS-A; ages 3–18 in the continental U.S) ([https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2946114/pdf/nihms214371.pdf 2011])<ref name="MerikangasEtAl2010" /> |2.2% | World Health Organization Composite International Diagnostic Interview (WHO-CIDI) |- |Adolescents in all of U.S.A |National Comorbidity Survey Replication Adolescent Supplement (NCS-A; ages 3–18 in the continental U.S)<ref name=":3">Kessler, R. C., Avenevoli, S., Costello, E. J., Georgiades, K., Green, J. G., Gruber, M. J., . . . Merikangas, K. R. (2012). Prevalence, persistence, and sociodemographic correlates of DSM-IV disorders in the National Comorbidity Survey Replication Adolescent Supplement. Archives of General Psychiatry, 69(4), 372-380. doi:10.1001/archgenpsychiatry.2011.160</ref> |5.4% |Composite International Diagnostic Interview (CIDI) |- | North Carolina | Rural community sample African American and White youth (ages 13-16) [https://www.ncbi.nlm.nih.gov/pubmed/12365876 (2002)]<ref>{{Cite journal|last=Angold|first=Adrian|last2=Erkanli|first2=Alaattin|last3=Farmer|first3=Elizabeth M. Z.|last4=Fairbank|first4=John A.|last5=Burns|first5=Barbara J.|last6=Keeler|first6=Gordon|last7=Costello|first7=E. Jane|date=October 2002|title=Psychiatric disorder, impairment, and service use in rural African American and white youth|url=https://www.ncbi.nlm.nih.gov/pubmed/12365876|journal=Archives of General Psychiatry|volume=59|issue=10|pages=893–901|issn=0003-990X|pmid=12365876}}</ref> |1.4% | The Child and Adolescent Psychiatric Assessment (CAPA) |- | Texas | Metropolitan Community Sample (ages 11-17) ([https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2736593/pdf/nihms30019.pdf 2007])<ref name="RobertsEtAl2007" /> |0.4% | Diagnostic Interview Schedule for Children, Version IV (DISC-IV) |- | Midwestern Urban | Incarcerated adolescents (ages 10-18)<ref>{{Cite journal|last=ABRAM|first=KAREN M.|last2=CHOE|first2=JEANNE Y.|last3=WASHBURN|first3=JASON J.|last4=TEPLIN|first4=LINDA A.|last5=KING|first5=DEVON C.|last6=DULCAN|first6=MINA K.|title=Suicidal Ideation and Behaviors Among Youths in Juvenile Detention|url=http://linkinghub.elsevier.com/retrieve/pii/S0890856709623121|journal=Journal of the American Academy of Child & Adolescent Psychiatry|volume=47|issue=3|pages=291–300|doi=10.1097/chi.0b013e318160b3ce}}</ref> [http://vb3lk7eb4t.search.serialssolutions.com/?ctx_ver=Z39.88-2004&ctx_enc=info%3Aofi%2Fenc%3AUTF-8&rfr_id=info%3Asid%2Fsummon.serialssolutions.com&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=Suicidal+Ideation+and+Behaviors+Among+Youths+in+Juvenile+Detention&rft.jtitle=Journal+of+the+American+Academy+of+Child+%26+Adolescent+Psychiatry&rft.au=ABRAM%2C+KAREN+M.%2C+Ph.D&rft.au=CHOE%2C+JEANNE+Y.%2C+B.A&rft.au=WASHBURN%2C+JASON+J.%2C+Ph.D.%2C+A.B.P.P&rft.au=TEPLIN%2C+LINDA+A.%2C+Ph.D&rft.date=2008&rft.issn=0890-8567&rft.eissn=1527-5418&rft.volume=47&rft.issue=3&rft.spage=291&rft.epage=300&rft_id=info:doi/10.1097%2FCHI.0b013e318160b3ce&rft.externalDocID=1_s2_0_S0890856709623121 (2002)] |1% | Diagnostic Interview Schedule for Children, Version IV (DISC-IV) |- |Non-institutionalized general US population |LGBTQ sample (ages 20-65)<ref>{{Cite journal|last=Bostwick|first=Wendy B.|last2=Boyd|first2=Carol J.|last3=Hughes|first3=Tonda L.|last4=McCabe|first4=Sean Esteban|date=2010-3|title=Dimensions of Sexual Orientation and the Prevalence of Mood and Anxiety Disorders in the United States|url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2820045/|journal=American Journal of Public Health|volume=100|issue=3|pages=468–475|doi=10.2105/AJPH.2008.152942|issn=0090-0036|pmc=PMC2820045|pmid=19696380}}</ref> [http://ajph.aphapublications.org/doi/10.2105/AJPH.2008.152942 (2013)] |Women: 14.8% same-sex 22.5% bisexual Men: 16.9% same-sex 11.5% bisexual |The Alcohol Use Disorder and Associated Disabilities Interview Schedule-IV (AUDADIS-IV) |- |Non-institutionalized general US population |Cross-ethnic American population (ages 18+)<ref>{{Cite journal|last=Asnaani|first=Anu|last2=Richey|first2=J. Anthony|last3=Dimaite|first3=Ruta|last4=Hinton|first4=Devon E.|last5=Hofmann|first5=Stefan G.|date=2010-8|title=A Cross-Ethnic Comparison of Lifetime Prevalence Rates of Anxiety Disorders|url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2931265/|journal=The Journal of nervous and mental disease|volume=198|issue=8|pages=551–555|doi=10.1097/NMD.0b013e3181ea169f|issn=0022-3018|pmc=PMC2931265|pmid=20699719}}</ref> [https://journals.lww.com/jonmd/Abstract/2010/08000/A_Cross_Ethnic_Comparison_of_Lifetime_Prevalence.4.aspx (2018)] |White 8.6% African Americans 4.9% Hispanic Americans 5.8% Asian Americans 2.4% |World Mental Health Survey Initiative Version of the World Health Organization Composite International Interview (WMH-CIDI) |- |Outpatient clinics worldwide |Samples across multiple studies worldwide (all ages)<ref name=":12">{{Cite journal|last=Rettew|first=David C.|last2=Lynch|first2=Alicia Doyle|last3=Achenbach|first3=Thomas M.|last4=Dumenci|first4=Levent|last5=Ivanova|first5=Masha Y.|date=2009-09|title=Meta-analyses of agreement between diagnoses made from clinical evaluations and standardized diagnostic interviews|url=http://dx.doi.org/10.1002/mpr.289|journal=International Journal of Methods in Psychiatric Research|language=en|volume=18|issue=3|pages=169–184|doi=10.1002/mpr.289|issn=1049-8931}}</ref> |5% |Clinical evaluations |- |Outpatient clinic worldwide |Samples across multiple studies worldwide (all ages)<ref name=":12" /> |10% |Standardized Diagnostic Interviews (SDIs) |- |People during pregnancy and postpartum |Samples across multiple studies worldwide<ref>{{Cite journal|last=Fawcett|first=Emily J.|last2=Fairbrother|first2=Nichole|last3=Cox|first3=Megan L.|last4=White|first4=Ian R.|last5=Fawcett|first5=Jonathan M.|date=2019-07-23|title=The Prevalence of Anxiety Disorders During Pregnancy and the Postpartum Period: A Multivariate Bayesian Meta-Analysis|url=https://www.psychiatrist.com/JCP/article/Pages/2019/v80/18r12527.aspx|journal=The Journal of Clinical Psychiatry|volume=80|issue=4|doi=10.4088/JCP.18r12527|issn=1555-2101|pmc=PMC6839961|pmid=31347796}}</ref> |2.4% |Standardized Diagnostic Interviews (SDIs) |- |Older adults |Samples across in Switzerland, German, Italy, England, Spain, and Israel |3.7% (age 65-69) 3.7% (age 70-74) 2.6% (age 75-79) 2.0% (age >80) |Clinical evaluations |} '''Search terms:''' [General Anxiety Disorder] AND [prevalence OR incidence] in GoogleScholar and PsycINFO == [[Evidence based assessment/Prediction phase|'''Prediction phase''']] == === Psychometric properties of screening instruments for GAD === The following section contains a list of screening and diagnostic instruments for generalized anxiety disorder. The section includes administration information, psychometric data, and PDFs or links to the screenings. * Screenings are used as part of the [[Evidence based assessment/Prediction phase|prediction phase]] of assessment; for more information on interpretation of this data, or how screenings fit in to the assessment process, click [[Evidence based assessment/Prediction phase|here]]. * '''''For a list of more broadly reaching screening instruments, [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prediction_phase&wteswitched=1#Psychometric_properties_of_common_screening_instruments click here.]''''' {| class="wikitable sortable" border="1" ! colspan="5" |Screening measures for GAD |- ! Measure ! Format (Reporter) ! Age Range ! Administration/ Completion Time ! style="width:12em" | Where to Access |- | Penn State Worry Questionnaire (PSWQ)<ref name=":0">{{Cite book|url=https://www.worldcat.org/oclc/314222270|title=A guide to assessments that work|date=2008|publisher=Oxford University Press|author=Hunsley, John |author2=Mash, Eric J.|isbn=9780195310641|location=New York|oclc=314222270}}</ref> | Questionnaire (Adult Version, Child Version) | 18+ (Adult Version), 6-18 (Child Version) | 4 minutes |[http://www.midss.org/content/penn-state-worry-questionnaire-pswq PSWQ homepage] [https://mfr.osf.io/render?url=https://osf.io/s7p38/?action=download%26mode=render PSWQ Adult Version] [https://mfr.osf.io/render?url=https://osf.io/6q8y9/?action=download%26mode=render PSWQ Child Version] [https://mfr.osf.io/render?url=https://osf.io/gx5sr/?action=download%26mode=render PSWC-C Korean] [https://mfr.osf.io/render?url=https://osf.io/hc6n2/?action=download%26mode=render PSWQ-C Danish] [https://mfr.osf.io/render?url=https://osf.io/fwbes/?action=download%26mode=render Scoring the PSWQ-C] |- |[[wikipedia:Screen_for_child_anxiety_related_disorders|Screen for Child Anxiety Related Emotional Disorder (SCARED)]]<ref name=":0" /> | Questionnaire (Child, Parent) | 8-19 | 9 or 16 minutes |[http://www.midss.org/content/screen-child-anxiety-related-disorders-scared SCARED] homepage [[wikipedia:Screen_for_child_anxiety_related_disorders#PDFs_and_automated_scoring_for_SCARED|SCARED English + Translations & Automatic Scoring]] |- |Child Behavior Checklist (CBCL)<ref name=":0" /> |Questionnaire (Parent report) |6-18 |10 minutes |[https://aseba.org/ ASEBA homepage][https://store.aseba.org/ Purchase] |} === Likelihood ratios and AUCs of screening instruments for GAD === * '''''For a list of the likelihood ratios for more broadly reaching screening instruments, [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prediction_phase&wteswitched=1#Likelihood_ratios_and_AUCs_of_common_screening_instruments click here.]''''' {| class="wikitable sortable" border="1" ! Screening Measure (Primary Reference) ! Area Under Curve (AUC) ! LR+ (Score) ! LR- (Score) ! Clinical Generalizability !Where to Access |- | Penn State Worry Questionnaire (PSWQ)<ref name=":2">{{Cite journal|last=Fresco|first=David M.|last2=Mennin|first2=Douglas S.|last3=Heimberg|first3=Richard G.|last4=Turk|first4=Cynthia L.|title=Using the Penn State Worry Questionnaire to identify individuals with generalized anxiety disorder: a receiver operating characteristic analysis|url=http://linkinghub.elsevier.com/retrieve/pii/S0005791603000569|journal=Journal of Behavior Therapy and Experimental Psychiatry|volume=34|issue=3-4|pages=283–291|doi=10.1016/j.jbtep.2003.09.001}}</ref> | 0.74 (N=164) | 1.8 (65+) | 0.5 (< 65) | Generalized Anxiety Disorder vs. social anxiety disorder, adults presenting to specialty anxiety clinic |[https://mfr.osf.io/render?url=https://osf.io/s7p38/?action=download%26mode=render PSWQ Adult Version] [https://mfr.osf.io/render?url=https://osf.io/6q8y9/?action=download%26mode=render PSWQ Child Version] |- |[[wikipedia:Screen_for_child_anxiety_related_disorders#PDFs_and_automated_scoring_for_SCARED|Screen for Child Anxiety Related Disorders (SCARED)]]<ref name="BirmaherEtAl1997" /> | .70 (N=243) | 5.0 (+32) | .04 | High: Pure anxiety disorder versus non-anxiety psychiatric disorder, excluding children with disruptive disorder and depression |[http://www.midss.org/content/penn-state-worry-questionnaire-pswq SCARED English + Translations & Automatic Scoring] |- |CBCL Anxious/Depressed Scale T-score<ref>{{Cite journal|last=Eimecke|first=Sylvia D.|last2=Remschmidt|first2=Helmut|last3=Mattejat|first3=Fritz|date=2011-03|title=Utility of the Child Behavior Checklist in screening depressive disorders within clinical samples|url=https://linkinghub.elsevier.com/retrieve/pii/S0165032710005458|journal=Journal of Affective Disorders|language=en|volume=129|issue=1-3|pages=191–197|doi=10.1016/j.jad.2010.08.011}}</ref> |.75 (N = 1445) |1.49 (9+) |.67(9-) |Inpatient and outpatient children and adolescents |[https://store.aseba.org/ Purchase] |} '''Note:''' “LR+” refers to the change in likelihood ratio associated with a positive test score, and “LR-” is the likelihood ratio for a low score. Likelihood ratios of 1 indicate that the test result did not change impressions at all. LRs larger than 10 or smaller than .10 are frequently clinically decisive; 5 or .20 are helpful, and between 2.0 and .5 are small enough that they rarely result in clinically meaningful changes of formulation<ref>Sackett, D. L., Straus, S. E., Richardson, W. S., Rosenberg, W., & Haynes, R. B. (2000). Evidence-based medicine: How to practice and teach EBM. Edinburgh: Churchill Livingstone.</ref>. '''Search terms:''' [General Anxiety Disorder] AND [children OR adolescents OR pediatric] AND [sensitivity OR specificity] in GoogleScholar and PsycINFO === Interpreting depression screening measure scores === * For information on interpreting screening measure scores, click [[Evidence based assessment/Prediction phase#Interpreting screening measure scores|here.]] ==[[Evidence based assessment/Prescription phase|'''Prescription phase''']]== ===Gold standard diagnostic interviews=== * For a list of broad reaching diagnostic interviews sortable by disorder with PDFs (if applicable), [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prescription_phase&wteswitched=1#Common_Diagnostic_Interviews click here.] === Recommended diagnostic instruments for GAD === {| class="wikitable sortable" ! colspan="5" |Diagnostic instruments for GAD |- !Measure !Format (Reporter) !Age Range !Administration/ Completion Time !Where to Access |- |Anxiety Disorders Interview Schedule for Children/Parent<ref name=":1">{{Cite journal|date=2001-08-01|title=Test-Retest Reliability of Anxiety Symptoms and Diagnoses With the Anxiety Disorders Interview Schedule for DSM-IV: Child and Parent Versions|url=https://www.sciencedirect.com/science/article/pii/S0890856709603427|journal=Journal of the American Academy of Child & Adolescent Psychiatry|language=en|volume=40|issue=8|pages=937–944|doi=10.1097/00004583-200108000-00016|issn=0890-8567}}</ref> |Structured Interview (Child (ADIS-C), Parent (ADIS-P)) |6-16<ref>{{Cite journal|last=LYNEHAM|first=HEIDI J.|last2=ABBOTT|first2=MAREE J.|last3=RAPEE|first3=RONALD M.|date=2007-06|title=Interrater Reliability of the Anxiety Disorders Interview Schedule for DSM-IV: Child and Parent Version|url=https://doi.org/10.1097/chi.0b013e3180465a09|journal=Journal of the American Academy of Child &amp; Adolescent Psychiatry|volume=46|issue=6|pages=731–736|doi=10.1097/chi.0b013e3180465a09|issn=0890-8567}}</ref> |Varies |[https://books.google.com/books/about/Anxiety_Disorders_Interview_Schedule_for.html?id=xpR6V3rboxwC Purchase] |- |Anxiety and Related Disorders Interview Schedule for DSM-5 (ADIS-5)<ref name=":0" /> |Structured Interview (Adult) |16+ |Varies |[https://global.oup.com/academic/product/anxiety-and-related-disorders-interview-schedule-for-dsm-5-adis-5---adult-version-9780199325160?cc=us&lang=en& Purchase] |- |Structured Clinical Interview for DSM-5-Clinician Version (SCID-5-CV)<ref>{{Cite journal|last=Shabani|first=Amir|last2=Masoumian|first2=Samira|last3=Zamirinejad|first3=Somayeh|last4=Hejri|first4=Maryam|last5=Pirmorad|first5=Tahereh|last6=Yaghmaeezadeh|first6=Hooman|date=2021-05|title=Psychometric properties of Structured Clinical Interview for DSM‐5 Disorders‐Clinician Version (SCID‐5‐CV)|url=https://onlinelibrary.wiley.com/doi/10.1002/brb3.1894|journal=Brain and Behavior|language=en|volume=11|issue=5|doi=10.1002/brb3.1894|issn=2162-3279|pmc=PMC8119811|pmid=33729681}}</ref> |Structured Interview (Adult ) |16+ |Varies |[https://www.columbiapsychiatry.org/research/research-labs/diagnostic-and-assessment-lab/structured-clinical-interview-dsm-disorders-11 Website and purchase] |- |Generalized Anxiety Disorder Screener (GAD-7)<ref name=":0" /> |Questionnaire (Self-report) |18+ |5 minutes |[https://www.pfizerpcoa.com/general-anxiety-disorder-7-gad-7-screener GAD-7 homepage] [https://osf.io/szmpu GAD-7 PDF] |} ==[[Evidence based assessment/Process phase|'''Process phase''']]== The following section contains a list of process and outcome measures for generalized anxiety disorder. The section includes benchmarks based on published norms for several outcome and severity measures, as well as information about commonly used process measures. Process and outcome measures are used as part of the [[Evidence based assessment/Process phase|process phase]] of assessment. For more information of differences between process and outcome measures, see the page on the [[Evidence based assessment/Process phase|process phase of assessment]]. === Process measures === === Outcome and severity measures === * This table includes clinically significant benchmarks for '''(insert portfolio name here)''' specific outcome measures * Information on how to interpret this table can be [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Process_phase found here]. * Additionally, these [[Evidence based assessment/Vignettes|vignettes]] might be helpful resources for understanding appropriate adaptation of outcome measures in practice. *''<u>For clinically significant change benchmarks for the CBCL, YSR, and TRF total, externalizing, internalizing, and attention benchmarks,</u>'' [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Process_phase&wteswitched=1#Clinically_significant_change_benchmarks_for_widely-used_outcome_measures see here.] {| class="wikitable sortable" border="1" | colspan="7" |'''Clinically significant change benchmarks with common instruments for GAD''' |- | rowspan=1" style="text-align:center;font-size:130%;" | <b> Measure</b> | colspan="3" style="text-align:center;font-size:130%" width="300" | <b> Cut-off scores</b> | colspan="3" style="text-align:center;font-size:120%" | <b> Critical Change <br> (unstandardized scores)</b> |- | colspan="7" span style="font-size:110%; text-align:center;" | <b> Benchmarks Based on Published Norms</b> |- | colspan="1" | | style="text-align:center;font-size:110%" | <b> A</b> | style="text-align:center;font-size:110%" | <b> B</b> | style="text-align:center;font-size:110%" | <b> C</b> | style="text-align:center;font-size:110%" | <b> 95%</b> | style="text-align:center;font-size:110%" | <b> 90%</b> | style="text-align:center;font-size:110%" | <b> SE_difference</b> |- | rowspan="1" style="text-align:center;" | <b> GAD-7</b> | style=“text-align:center;”| -1 | style=“text-align:center;”| 1.3 | style=“text-align:center;”| 0.5 | style=“text-align:center;”| 0.6 | style=“text-align:center;”| 0.5 | style=“text-align:center;”| 0.3 |- | rowspan="1" style="text-align:center;" | <b> PSWQ</b> | style=“text-align:center;”| 51 | style=“text-align:center;”| 73 | style=“text-align:center;”| 59 | style=“text-align:center;”| 9 | style=“text-align:center;”| 8 | style=“text-align:center;”| 4.8 |- | rowspan="1" style="text-align:center;" | <b> SCARED </b> | style=“text-align:center;”| 9.9 | style=“text-align:center;”| 18.1 | style=“text-align:center;”| 15.3 | style=“text-align:center;”| 8.9 | style=“text-align:center;”| 7.5 | style=“text-align:center;”| 4.5 |} '''Note:''' “A” = Away from the clinical range, “B” = Back into the nonclinical range, “C” = Closer to the nonclinical than clinical mean. '''Search terms:''' [General Anxiety Disorder] AND [children OR adolescents OR pediatric] AND [clinical significance OR outcomes] in GoogleScholar and PsycINFO === Treatment === {{collapse top| Click here for treatment information}} Individuals suffering from GAD tend to be high users of outpatient medical care. When treating GAD, physicians should first determine whether pharmacotherapy, psychotherapy, or a combination of the two treatments would be most beneficial to the patient. Literature suggests that treatment of GAD frequently consists of a combination of psychotherapy and pharmacotherapy. Although these therapies have the potential to be effective individually, previous work demonstrates that when combined the degree of clinically significant change increases significantly. Recent studies (e.g., Gorman, 2003<ref name="Gorman2003" />; Walkup et al., 2008<ref name="WalkupEtAl2008" />) have provided evidence to support this claim with the most efficacious medication and behavioral interventions listed below. # '''Medication Interventions''' ## ''Sertraline (Zoloft)'' has been shown to reduce experiences and effects of GAD above and beyond that of placebo conditions. ## ''Pregabalin.'' The mean baseline-to-endpoint decreases in total Hamilton anxiety scale score in the patients given 150 mg/day of pregabalin (–9.2) was significantly greater than the decrease in those given placebo (–6.8)<ref name="PandeEtAl2003" />. ## ''Paroxetine.'' Remission was achieved by 30% of patients in the 20-mg paroxetine groups compared with 20% given placebo. For all three domains of the Sheehan Disability Scale, significantly greater improvement was seen with paroxetine than placebo<ref name="RickelsEtAl2003" />. # '''Behavioral interventions''' ## ''Cognitive behavioral therapy.'' Fourteen 60-minute sessions, which include CBT in anxiety-management skills, followed by behavioral exposure to anxiety-provoking situations have been shown to be effective in treating GAD. A review of studies by Fisher and Durham (1999)<ref name="FisherEtAl1999" /> revealed significant recovery rates at a 6 month follow up after CBT. ## ''Exposure therapy and modeling therapy.'' One meta-analysis found that virtual reality exposure therapy for anxiety disorders had a large effect size (Cohen's d=1.11) compared to controls.<ref>{{Cite journal|last=Powers|first=Mark B.|last2=Emmelkamp|first2=Paul M.G.|title=Virtual reality exposure therapy for anxiety disorders: A meta-analysis|url=https://doi.org/10.1016/j.janxdis.2007.04.006|journal=Journal of Anxiety Disorders|volume=22|issue=3|pages=561–569|doi=10.1016/j.janxdis.2007.04.006}}</ref> ## ''Mindfulness meditation.'' New treatment options such as mindfulness meditation-based stress reduction interventions have also shown to reduce symptoms over the long-term.<ref>{{Cite journal|last=Miller|first=J. J.|last2=Fletcher|first2=K.|last3=Kabat-Zinn|first3=J.|date=May 1995|title=Three-year follow-up and clinical implications of a mindfulness meditation-based stress reduction intervention in the treatment of anxiety disorders|url=https://www.ncbi.nlm.nih.gov/pubmed/7649463|journal=General Hospital Psychiatry|volume=17|issue=3|pages=192–200|issn=0163-8343|pmid=7649463}}</ref> # '''Combination treatment''' ## Previous research suggests that combination therapy that includes components of psychotherapy and pharmacotherapy are the most efficacious in treating GAD. In a study comparing the efficacies GAD treatments, Walkup and colleagues demonstrated a 21-25% improvement of combination therapy over cognitive behavioral therapy or sertraline alone during short-term treatment. These findings suggest that among effective treatments, combination therapy has the potential to provide the best chance for a positive outcome. See Gorman, 2003<ref name="Gorman2003" />; Walkup et al., 2008<ref name="WalkupEtAl2008" />. {{collapse bottom}} * Please refer to the page on [[wikipedia:Generalized_anxiety_disorder|generalized anxiety disorder]] for more information on available treatment or go to [http://effectivechildtherapy.org/concerns-symptoms-disorders/disorders/fear-worry-and-anxiety/ Effective Child Therapy] for a curated resource on effective treatments for GAD. *For information on conducting Exposure Therapy for anxiety disordered youth, see [https://www.bravepracticeforkids.com/ www.BravePracticeForKids.com] =='''External Resources'''== # [http://apps.who.int/classifications/icd10/browse/2010/en#/F41.1 ICD-10 diagnostic criteria] # [https://en.wikiversity.org/w/index.php?title=Helping_Give_Away_Psychological_Science/Resources/Annotated_List_of_Where_and_How_to_Find_a_Therapist&wteswitched=1#Other_low-cost_options Find-a-Therapist] #*This is a curated list of find-a-therapist websites where you can find a provider # [https://www.nimh.nih.gov/health/topics/anxiety-disorders/index.shtml NIMH] entry about anxiety disorders # OMIM (Online Mendelian Inheritance in Man) #*[https://www.omim.org/entry/607834 607834] # [https://emedicine.medscape.com/article/286227-overview#a2 eMedicine entry about anxiety disorders] #[https://sccap53.org Society of Clinical Child and Adolescent Psychology] #[http://effectivechildtherapy.org/concerns-symptoms-disorders/disorders/fear-worry-and-anxiety/ Effective Child Therapy information on Fear, Worry, & Anxiety] #*Effective Child Therapy is website sponsored by Division 53 of the American Psychological Association (APA), or The [https://sccap53.org Society of Clinical Child and Adolescent Psychology] (SCCAP), in collaboration with the Association for Behavioral and Cognitive Therapies (ABCT). Use for information on symptoms and available treatments. #[http://pediatricbipolar.pitt.edu/resources/instruments Links to SCARED Child, Parent, and Adult + Translations] =='''References'''== {{collapse top|Click here for references}} {{Reflist|3|refs= <ref name="BirmaherEtAl1997">{{cite journal|last1=Birmaher|first1=B|last2=Khetarpal|first2=S|last3=Brent|first3=D|last4=Cully|first4=M|last5=Balach|first5=L|last6=Kaufman|first6=J|last7=Neer|first7=SM|title=The Screen for Child Anxiety Related Emotional Disorders (SCARED): scale construction and psychometric characteristics.|journal=Journal of the American Academy of Child and Adolescent Psychiatry|date=April 1997|volume=36|issue=4|pages=545-53|pmid=9100430}}</ref> <ref name="BrownJacobsenEtAl2011">{{cite journal|last1=Brown-Jacobsen|first1=AM|last2=Wallace|first2=DP|last3=Whiteside|first3=SP|title=Multimethod, multi-informant agreement, and positive predictive value in the identification of child anxiety disorders using the SCAS and ADIS-C.|journal=Assessment|date=September 2011|volume=18|issue=3|pages=382-92|pmid=20644080}}</ref> <ref name="CostelloEtAl1996">{{cite journal|last1=Costello|first1=EJ|last2=Angold|first2=A|last3=Burns|first3=BJ|last4=Stangl|first4=DK|last5=Tweed|first5=DL|last6=Erkanli|first6=A|last7=Worthman|first7=CM|title=The Great Smoky Mountains Study of Youth. Goals, design, methods, and the prevalence of DSM-III-R disorders.|journal=Archives of general psychiatry|date=December 1996|volume=53|issue=12|pages=1129-36|pmid=8956679}}</ref> <ref name="ChorpitaEtAl2000">{{cite journal|last1=Chorpita|first1=BF|last2=Yim|first2=L|last3=Moffitt|first3=C|last4=Umemoto|first4=LA|last5=Francis|first5=SE|title=Assessment of symptoms of DSM-IV anxiety and depression in children: a revised child anxiety and depression scale.|journal=Behaviour research and therapy|date=August 2000|volume=38|issue=8|pages=835-55|pmid=10937431}}</ref> <ref name="ChorpitaEtAl2005">{{cite journal|last1=Chorpita|first1=BF|last2=Moffitt|first2=CE|last3=Gray|first3=J|title=Psychometric properties of the Revised Child Anxiety and Depression Scale in a clinical sample.|journal=Behaviour research and therapy|date=March 2005|volume=43|issue=3|pages=309-22|pmid=15680928}}</ref> <ref name="FisherEtAl1999">{{cite journal|last1=Fisher|first1=PL|last2=Durham|first2=RC|title=Recovery rates in generalized anxiety disorder following psychological therapy: an analysis of clinically significant change in the STAI-T across outcome studies since 1990.|journal=Psychological medicine|date=November 1999|volume=29|issue=6|pages=1425-34|pmid=10616949}}</ref> <ref name="Gorman2003">{{cite journal|last1=Gorman|first1=JM|title=Treating generalized anxiety disorder.|journal=The Journal of clinical psychiatry|date=2003|volume=64 Suppl 2|pages=24-9|pmid=12625796}}</ref> <ref name="HaleEtAl2014">{{cite journal|last1=Hale III|first1=WW|last2=Raaijmakers|first2=QA|last3=van Hoof|first3=A|last4=Meeus|first4=WH|title=Improving Screening Cut-Off Scores for DSM-5 Adolescent Anxiety Disorder Symptom Dimensions with the Screen for Child Anxiety Related Emotional Disorders.|journal=Psychiatry journal|date=2014|volume=2014|pages=517527|pmid=24829901}}</ref> <ref name="KayeEtAl2004">{{cite journal|last1=Kaye|first1=WH|last2=Bulik|first2=CM|last3=Thornton|first3=L|last4=Barbarich|first4=N|last5=Masters|first5=K|title=Comorbidity of anxiety disorders with anorexia and bulimia nervosa.|journal=The American journal of psychiatry|date=December 2004|volume=161|issue=12|pages=2215-21|pmid=15569892}}</ref> <ref name="KesslerEtAl2012">{{cite journal|last1=Kessler|first1=RC|last2=Petukhova|first2=M|last3=Sampson|first3=NA|last4=Zaslavsky|first4=AM|last5=Wittchen H|first5=-U|title=Twelve-month and lifetime prevalence and lifetime morbid risk of anxiety and mood disorders in the United States.|journal=International journal of methods in psychiatric research|date=September 2012|volume=21|issue=3|pages=169-84|pmid=22865617}}</ref> <ref name="LynehamEtAl2007">{{cite journal|last1=Lyneham|first1=HJ|last2=Abbott|first2=MJ|last3=Rapee|first3=RM|title=Interrater reliability of the Anxiety Disorders Interview Schedule for DSM-IV: child and parent version.|journal=Journal of the American Academy of Child and Adolescent Psychiatry|date=June 2007|volume=46|issue=6|pages=731-6|pmid=17513985}}</ref> <ref name="MarchEtAl1997">{{cite journal|last1=March|first1=JS|last2=Parker|first2=JD|last3=Sullivan|first3=K|last4=Stallings|first4=P|last5=Conners|first5=CK|title=The Multidimensional Anxiety Scale for Children (MASC): factor structure, reliability, and validity.|journal=Journal of the American Academy of Child and Adolescent Psychiatry|date=April 1997|volume=36|issue=4|pages=554-65|pmid=9100431}}</ref> <ref name="McLeanEtAl2011">{{cite journal|last1=McLean|first1=CP|last2=Asnaani|first2=A|last3=Litz|first3=BT|last4=Hofmann|first4=SG|title=Gender differences in anxiety disorders: prevalence, course of illness, comorbidity and burden of illness.|journal=Journal of psychiatric research|date=August 2011|volume=45|issue=8|pages=1027-35|pmid=21439576}}</ref> <ref name="MerikangasEtAl2010">{{cite journal|last1=Merikangas|first1=KR|last2=He|first2=JP|last3=Burstein|first3=M|last4=Swanson|first4=SA|last5=Avenevoli|first5=S|last6=Cui|first6=L|last7=Benjet|first7=C|last8=Georgiades|first8=K|last9=Swendsen|first9=J|title=Lifetime prevalence of mental disorders in U.S. adolescents: results from the National Comorbidity Survey Replication--Adolescent Supplement (NCS-A).|journal=Journal of the American Academy of Child and Adolescent Psychiatry|date=October 2010|volume=49|issue=10|pages=980-9|pmid=20855043}}</ref> <ref name="PandeEtAl2003">{{cite journal|last1=Pande|first1=AC|last2=Crockatt|first2=JG|last3=Feltner|first3=DE|last4=Janney|first4=CA|last5=Smith|first5=WT|last6=Weisler|first6=R|last7=Londborg|first7=PD|last8=Bielski|first8=RJ|last9=Zimbroff|first9=DL|last10=Davidson|first10=JR|last11=Liu-Dumaw|first11=M|title=Pregabalin in generalized anxiety disorder: a placebo-controlled trial.|journal=The American journal of psychiatry|date=March 2003|volume=160|issue=3|pages=533-40|pmid=12611835}}</ref> <ref name="RickelsEtAl2003">{{cite journal|last1=Rickels|first1=K|last2=Zaninelli|first2=R|last3=McCafferty|first3=J|last4=Bellew|first4=K|last5=Iyengar|first5=M|last6=Sheehan|first6=D|title=Paroxetine treatment of generalized anxiety disorder: a double-blind, placebo-controlled study.|journal=The American journal of psychiatry|date=April 2003|volume=160|issue=4|pages=749-56|pmid=12668365}}</ref> <ref name="RobertsEtAl2007">{{cite journal|last1=Roberts|first1=RE|last2=Roberts|first2=CR|last3=Xing|first3=Y|title=Rates of DSM-IV psychiatric disorders among adolescents in a large metropolitan area.|journal=Journal of psychiatric research|date=December 2007|volume=41|issue=11|pages=959-67|pmid=17107689}}</ref> <ref name="SeligmanEtAl2004">{{cite journal|last1=Seligman|first1=LD|last2=Ollendick|first2=TH|last3=Langley|first3=AK|last4=Baldacci|first4=HB|title=The utility of measures of child and adolescent anxiety: a meta-analytic review of the Revised Children's Manifest Anxiety Scale, the State-Trait Anxiety Inventory for Children, and the Child Behavior Checklist.|journal=Journal of clinical child and adolescent psychology : the official journal for the Society of Clinical Child and Adolescent Psychology, American Psychological Association, Division 53|date=September 2004|volume=33|issue=3|pages=557-65|pmid=15271613}}</ref> <ref name="WalkupEtAl2008">{{cite journal|last1=Walkup|first1=JT|last2=Albano|first2=AM|last3=Piacentini|first3=J|last4=Birmaher|first4=B|last5=Compton|first5=SN|last6=Sherrill|first6=JT|last7=Ginsburg|first7=GS|last8=Rynn|first8=MA|last9=McCracken|first9=J|last10=Waslick|first10=B|last11=Iyengar|first11=S|last12=March|first12=JS|last13=Kendall|first13=PC|title=Cognitive behavioral therapy, sertraline, or a combination in childhood anxiety.|journal=The New England journal of medicine|date=25 December 2008|volume=359|issue=26|pages=2753-66|pmid=18974308}}</ref> <ref name="WhitakerEtAl1990">{{cite journal|last1=Whitaker|first1=A|last2=Johnson|first2=J|last3=Shaffer|first3=D|last4=Rapoport|first4=JL|last5=Kalikow|first5=K|last6=Walsh|first6=BT|last7=Davies|first7=M|last8=Braiman|first8=S|last9=Dolinsky|first9=A|title=Uncommon troubles in young people: prevalence estimates of selected psychiatric disorders in a nonreferred adolescent population.|journal=Archives of general psychiatry|date=May 1990|volume=47|issue=5|pages=487-96|pmid=2331210}}</ref> <ref name="SpitzerEtAl2006">{{cite journal|last1=Spitzer|first1=RL|last2=Kroenke|first2=K|last3=Williams|first3=JB|last4=Löwe|first4=B|title=A brief measure for assessing generalized anxiety disorder: the GAD-7.|journal=Archives of internal medicine|date=22 May 2006|volume=166|issue=10|pages=1092-7|pmid=16717171}}</ref> <ref name="vanGastelEtAl2008">{{cite journal|last1=van Gastel|first1=W|last2=Ferdinand|first2=RF|title=Screening capacity of the Multidimensional Anxiety Scale for Children (MASC) for DSM-IV anxiety disorders.|journal=Depression and anxiety|date=2008|volume=25|issue=12|pages=1046-52|pmid=18833579}}</ref> <ref name="WoodEtAl2002">{{cite journal|last1=Wood|first1=JJ|last2=Piacentini|first2=JC|last3=Bergman|first3=RL|last4=McCracken|first4=J|last5=Barrios|first5=V|title=Concurrent validity of the anxiety disorders section of the Anxiety Disorders Interview Schedule for DSM-IV: child and parent versions.|journal=Journal of clinical child and adolescent psychology : the official journal for the Society of Clinical Child and Adolescent Psychology, American Psychological Association, Division 53|date=September 2002|volume=31|issue=3|pages=335-42|pmid=12149971}}</ref> <ref name="ZimmermanEtAl2005">{{cite journal|last1=Zimmerman|first1=M|last2=Rothschild|first2=L|last3=Chelminski|first3=I|title=The prevalence of DSM-IV personality disorders in psychiatric outpatients.|journal=The American journal of psychiatry|date=October 2005|volume=162|issue=10|pages=1911-8|pmid=16199838}}</ref> }} {{collapse bottom|Click here for references}} [[Category:Psychological disorder portfolios|{{SUBPAGENAME}}]] bfsca3ccc3b3pbn3b5ziyhit6osvdwo 0 207106 2413997 2413681 2022-08-12T18:37:03Z Sophiebirky 2946510 /* Likelihood ratios and AUCs of screening measures for OCD */ deleted row wikitext text/x-wiki <noinclude>{{Helping Give Away Psychological Science Banner}}</noinclude> {{medical disclaimer}} {{:{{BASEPAGENAME}}/Sidebar}} ==[[Evidence based assessment/Portfolio template/What is a "portfolio"|'''What is a "portfolio"?''']]== For background information on what assessment portfolios are, click the link in the heading above. Want even more information about this topic? There's an extended version of this page [[Evidence-based assessment/Obsessive-compulsive disorder (assessment portfolio)/extended version|here]]. ==[[Evidence based assessment/Preparation phase|'''Preparation phase''']]== === Diagnostic criteria for obsessive-compulsive disorder === {{blockquotetop}}'''ICD-11 Criteria''' <ref>{{Cite web|url=http://apps.who.int/classifications/icd10/browse/2016/en#/F40-F48|title=ICD-10 Version:2016|website=apps.who.int|language=en|accessdate=2018-03-01}}</ref> Obsessive-Compulsive Disorder is characterized by the presence of persistent obsessions or compulsions, or most commonly both. Obsessions are repetitive and persistent thoughts, images, or impulses/urges that are intrusive, unwanted, and are commonly associated with anxiety. The individual attempts to ignore or suppress obsessions or to neutralize them by performing compulsions. Compulsions are repetitive behaviors including repetitive mental acts that the individual feels driven to perform in response to an obsession, according to rigid rules, or to achieve a sense of ‘completeness’. In order for obsessive-compulsive disorder to be diagnosed, obsessions and compulsions must be time consuming (e.g., taking more than an hour per day), and result in significant distress or significant impairment in personal, family, social, educational, occupational or other important areas of functioning. Inclusions *anankastic neurosis *obsessive-compulsive neurosis Exclusions *obsessive compulsive behaviour (MB23.4) '''Changes in DSM-5''' * The diagnostic criteria for obsessive-compulsive disorder changed slightly from DSM-IV-TR to DSM-5. Summaries are available [https://en.wikipedia.org/wiki/DSM-5 here]. {{blockquotebottom}} === Base rates of obsessive-compulsive in different populations and clinical settings=== {| class="wikitable sortable" border="1" |- ! Demography ! Setting ! Base Rate ! Diagnostic Method |- |National (U.S.) adult sample (n=2073)<ref name="RuscioEtAl2010" /> |National Comorbidity Survey Replication |2.3% |World Health Organization Composite International Diagnostic Interview (CIDI 3.0) |- |U.S. household sample (n=18572)<ref name="KarnoEtAl1988" /> |Epidemiological Catchment Area (ECA) Program |1.9-3.3% |Diagnostic Interview Schedule (DIS) |- |Iranian adults (n=25180)<ref name="MohammadiEtAl2004" /> |Iranian population-based study |1.8% |DIS |- |NSAL adult study (n=5191)<ref name="HimleEtAl2008" /> |African-American and Caribbean Households (U.S.) |1.6% |CIDI Short Form |- |Epidemiological sample (n=6616)<ref name="SubramaniamEtAl2012" /> |Singapore Mental Health Study |3.0% |CIDI 3.0 |} '''Search terms:''' [obsessive compulsive disorder OR ocd] AND [prevalence OR incidence] in PsycInfo and PubMed [obsessive compulsive disorder OR ocd] AND [epidemiology] in PsycInfo and PubMed ==[[Evidence based assessment/Prediction phase|'''Prediction phase''']]== ===Recommended screening instruments === The following section contains a list of screening and diagnostic instruments for obsessive-compulsive disorder. {| class="wikitable sortable" border="1" |- ! Screening Instrument ! Format ! Age Range ! Administration Time !Where to Access |- | Children’s Florida Obsessive–Compulsive Inventory (C-FOCI) <ref name=":2">Eric A. Youngstrom, Mitchell J. Prinstein, Eric J. Mash, & Russell A. Barkley. (2020). Assessment of Disorders in Childhood and Adolescence, Fifth Edition: Vol. Fifth edition. The Guilford Press</ref> | Self-report | 7-17 years | |[https://iocdf.org/wp-content/uploads/2014/11/Storch-et-al.-CFOCI-Article.pdf C-FOCI] |- |Obsessive–Compulsive Inventory—Child Version (OCI-CV) <ref name=":2" /> | Self-report | 7-17 years | |[https://pubmed.ncbi.nlm.nih.gov/20171333/ OCI-CV] |- | Children’s Obsessional Compulsive Inventory (CHOCI) <ref name=":2" /> | Self-report | 7-17 years | |[https://www.projectimplicit.net/bethany/papers/ShafranFramptonHeymanReynoldsTeachmanRachman2003.pdf CHOCI] |} === Likelihood ratios and AUCs of screening measures for OCD === * '''''For a list of the likelihood ratios for more broadly reaching screening instruments, [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prediction_phase&wteswitched=1#Likelihood_ratios_and_AUCs_of_common_screening_instruments click here.]''''' {| class="wikitable sortable" border="1" |- ! Screening Measure (Primary Reference) ! Area Under curve (AUC) and Sample Size ! LR+ (Score) ! LR- ! Clinical generalizability !Download Link |- | Y-BOCS-SR<ref name="SteketeeEtAl1996"/> | 0.75 (N=162) | 5.50 (7) | 0.50 | Moderate: OCD among pregnant and postpartum women |[https://static1.squarespace.com/static/58cab82ff5e231f0df8d9cad/t/60945b3af4680c68037f8188/1620335418443/YBOCS-II-SR.pdf Y-BOCS-SR] |- | OCI-R Total<ref name="FoaEtAl2002"/> | 0.81 (N=322) | 3.66 (14) | 0.44 | High: OCD (n=167) versus other anxiety disorders (n=155) at outpatient anxiety clinic |[https://serene.me.uk/tests/oci.pdf OCI-R Total] |- | OCI-R Total<ref name="FoaEtAl2002"/> | 0.82 (N=458) | 2.98 (18) | 0.36 | High: OCD (n=215) versus other anxiety disorders (n=243) at outpatient anxiety clinic |[https://serene.me.uk/tests/oci.pdf OCI-R Total] |- |Brown Assessment of Beliefs Scale<ref name=":1">Eisen, J. L., Phillips, K. A., Baer, L., Beer, D. A., & al, e. (1998). The brown assessment of beliefs scale: Reliability and validity. ''The American Journal of Psychiatry, 155''(1), 102-8. Retrieved from <nowiki>http://libproxy.lib.unc.edu/login?url=https://search.proquest.com/docview/220481418?accountid=14244</nowiki></ref> |(N=50) | | | |[http://www.veale.co.uk/wp-content/uploads/2010/11/BABS_revised_501.pdf BABS] |- |} *“LR+” refers to the change in likelihood ratio associated with a positive test score, and “LR-” is the likelihood ratio for a low score. Likelihood ratios of 1 indicate that the test result did not change impressions at all. LRs larger than 10 or smaller than .10 are frequently clinically decisive; 5 or .20 are helpful, and between 2.0 and .5 are small enough that they rarely result in clinically meaningful changes of formulation (Sackett et al., 2000). ==[[Evidence based assessment/Prescription phase|'''Prescription phase''']]== ===Gold standard diagnostic interviews=== * For a list of broad reaching diagnostic interviews sortable by disorder with PDFs (if applicable), [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prescription_phase&wteswitched=1#Common_Diagnostic_Interviews click here.] ===Recommended diagnostic interviews for OCD=== {| class="wikitable" |+ !Diagnostic Interview !Format !Age Range/ !Administration Time !Where to Access |- | Anxiety Disorders Interview Schedule<ref>Brown, T.A., Di Nardo, P.A., Barlow, D.H., 1994. Anxiety Disorders Interview Schedule for DSM-IV (ADIS-IV-L). Psychological Corporation, San Antonio, TX.</ref> | Semistructured interview | | |[https://www.sciencedirect.com/science/article/abs/pii/S0887618514001510?via%3Dihub ADIS-IV] |- |[https://mfr.osf.io/render?url=https://osf.io/mnzy2/?action=download%26mode=render Yale-Brown Obsessive Compulsive Scale Symptom Checklist]<ref name=":0">{{Cite journal|last=Steketee|first=G|title=The Yale-Brown Obsessive Compulsive Scale: Interview versus self-report|url=http://linkinghub.elsevier.com/retrieve/pii/0005796796000368|journal=Behaviour Research and Therapy|volume=34|issue=8|pages=675–684|doi=10.1016/0005-7967(96)00036-8}}</ref> | Semistructured interview | | Up to 60 mins |[https://www.ohsu.edu/sites/default/files/2019-06/Y-BOCS-Checklist_0.pdf Y-BOCS] |- | [https://search.proquest.com/docview/220481418/abstract/4AF689339CB14A0APQ/1?accountid=14244 Brown Assessment of Beliefs Scale]<ref name=":1">Eisen, J. L., Phillips, K. A., Baer, L., Beer, D. A., & al, e. (1998). The brown assessment of beliefs scale: Reliability and validity. ''The American Journal of Psychiatry, 155''(1), 102-8. Retrieved from <nowiki>http://libproxy.lib.unc.edu/login?url=https://search.proquest.com/docview/220481418?accountid=14244</nowiki></ref> | Semistructured interview | "older children" to adult | |[http://www.veale.co.uk/wp-content/uploads/2010/11/BABS_revised_501.pdf BABS] |- |OCD module of the Structured Clinical Interview for DSM-5 (SCID-5) |Semi-structured interview |18+ | |[https://www.appi.org/products/structured-clinical-interview-for-dsm-5-scid-5 SCID-5] |} ==[[Evidence based assessment/Process phase|'''Process phase''']]== === Treatments === ==== Cognitive behavioral therapy (CBT) and exposure and response prevention (ERP) ==== *Behavior therapy, specifically ERP, has been established as the treatment of choice for OCD <ref>Whittal M.L., McLean P.D., Söchting I., Koch W.J., Taylor S., Anderson K., Paterson R.'''OCD treatment outcome using behavioral and cognitive approaches''' Paper presented at the meeting of the Association for Advancement of Behavior Therapy, Miami Beach, FL (1997)</ref><ref>{{Cite journal|last=Foa|first=Edna B.|last2=Kozak|first2=Michael J.|title=Beyond the efficacy ceiling? Cognitive behavior therapy in search of theory|url=https://doi.org/10.1016/S0005-7894(97)80019-6|journal=Behavior Therapy|volume=28|issue=4|pages=601–611|doi=10.1016/s0005-7894(97)80019-6}}</ref>. *Therapy incorporates ERP and emphasizes cognitive change. **Therapist will help individual identify anxiety-provoking thoughts and situations. **Therapist will develop a treatment plan and idiographic “fear hierarchy.” **Individuals will learn to encounter situations that invoke anxiety without engaging in rituals used to dispel anxiety (ERP). **Exposures will be done gradually at a pace that is comfortable for the client. **Therapy will include homework assignments and is designed to offer lifelong skills. *Therapy includes verbal techniques such as psychoeducation and cognitive restructuring. *Manuals for reference: **The therapist guide: Mastery of Obsessive-Compulsive Disorder: A Cognitive Behavioral Approach<ref>E. Foa, M. Kozak Mastery of obsessive–compulsive disorder: A cognitive-behavioral approach Graywind Publications (1997)</ref> **Cognitive Therapy of Obsessive-Compulsive Disorder: A Guide for Professionals (Wilhelm & Steketee) **Obsessive Compulsive Disorder: Advances in Psychotherapy <ref>{{Cite book|url=https://www.worldcat.org/oclc/70659789|title=Obsessive compulsive disorder|last=S.|first=Abramowitz, Jonathan|date=2006|publisher=Hogrefe & Huber Publishers|isbn=9780889373167|location=Cambridge, MA|oclc=70659789}}</ref> *Treatment alliance is a predictor of subsequent change in OCD symptoms<ref>Keeley, M. L., Geffken, G. R., Ricketts, E., McNamara, J. P., & Storch, E. A. (2011). The therapeutic alliance in the cognitive behavioral treatment of pediatric obsessive–compulsive disorder. ''Journal of Anxiety Disorders'', ''25''(7), 855-863.</ref>. The therapist should provide a “validating and :encouraging” environment so that clients can tolerate the emotional arousal associated with exposures. ==== Medication ==== *Selective serotonin reuptake inhibitors (SSRIs) are commonly used to treat OCD. *These antidepressants include: **[[wikipedia:Fluvoxamine|fluvoxamine]] **[[wikipedia:Fluoxetine|fluoxetine]] **[[wikipedia:Sertraline|sertraline]] **[[wikipedia:Paroxetine|paroxetine]] **[[wikipedia:Citalopram|citalopram]] **[[wikipedia:Clomipramine|clomipramine]] **[[wikipedia:Escitalopram|escitalopram]] **[[wikipedia:Venlafaxine|venlafaxine]] *High doses (relative to doses prescribed for depression) are needed for individuals with OCD. === Process and outcome measures === ==== Clinically significant change benchmarks with common instruments and mood rating scales ==== {| class="wikitable sortable" border="1" |- | rowspan=1" style="text-align:center;font-size:130%;" | <b> Measure</b> | style="text-align:center;font-size:130%;" | <b> Subscale</b> | colspan="3" style="text-align:center;font-size:130%" width="300" | <b> Cut-off scores</b> | colspan="3" style="text-align:center;font-size:120%" | <b> Critical Change <br> (unstandardized scores)</b> |- | colspan="8" span style="font-size:110%; text-align:center;" | <b> Benchmarks Based on Published Norms</b> |- | colspan="2" | | style="text-align:center;font-size:110%" | <b> A</b> | style="text-align:center;font-size:110%" | <b> B</b> | style="text-align:center;font-size:110%" | <b> C</b> | style="text-align:center;font-size:110%" | <b> 95%</b> | style="text-align:center;font-size:110%" | <b> 90%</b> | style="text-align:center;font-size:110%" | <b> SE_difference</b> |- | rowspan="3" style="text-align:center;" | <b> Yale-Brown Obsessive Compulsive Scale (Y-BOCS-SR)</b> | style="text-align:right;" | <i> Total</i> | style="text-align:center;"| 10.6 | style="text-align:center;"| 14.4 | style="text-align:center;"| 12.6 | style="text-align:center;"| 4.7 | style="text-align:center;"| 3.9 | style="text-align:center;"| 2.4 |- | style="text-align:right;" | <i> Obsessions</i> | style="text-align:center;"| 6.6 | style="text-align:center;"| 7.6 | style="text-align:center;"| 7.0 | style="text-align:center;"| 2.5 | style="text-align:center;"| 2.1 | style="text-align:center;"| 1.3 |- | style="text-align:right;" | <i> Compulsions</i> | style="text-align:center;"| 3.5 | style="text-align:center;"| 8.2 | style="text-align:center;"| 6.1 | style="text-align:center;"| 3.6 | style="text-align:center;"| 3.0 | style="text-align:center;"| 1.8 |- | rowspan="7" style="text-align:center;" | <b> Obsessive-Compulsive Inventory – Revised (OCI-R)</b> | style="text-align:right;" | <i> Total</i> | style="text-align:center;"| 1.0 | style="text-align:center;"| 41.0 | style="text-align:center;"| 23.0 | style="text-align:center;"| 14.8 | style="text-align:center;"| 12.5 | style="text-align:center;"| 7.6 |- | style="text-align:right;" | <i> Washing</i> | style="text-align:center;"| n/a | style="text-align:center;"| 7.4 | style="text-align:center;"| 3.1 | style="text-align:center;"| 3.4 | style="text-align:center;"| 2.9 | style="text-align:center;"| 1.7 |- | style="text-align:right;" | <i> Checking</i> | style="text-align:center;"| n/a | style="text-align:center;"| 8.0 | style="text-align:center;"| 3.7 | style="text-align:center;"| 3.0 | style="text-align:center;"| 2.5 | style="text-align:center;"| 1.5 |- | style="text-align:right;" | <i> Ordering</i> | style="text-align:center;"| n/a | style="text-align:center;"| 10.5 | style="text-align:center;"| 4.6 | style="text-align:center;"| 3.1 | style="text-align:center;"| 2.6 | style="text-align:center;"| 1.6 |- | style="text-align:right;" | <i> Obsessing</i> | style="text-align:center;"| n/a | style="text-align:center;"| 8.3 | style="text-align:center;"| 4.7 | style="text-align:center;"| 3.8 | style="text-align:center;"| 3.2 | style="text-align:center;"| 1.9 |- | style="text-align:right;" | <i> Hoarding</i> | style="text-align:center;"| n/a | style="text-align:center;"| 9.8 | style="text-align:center;"| 4.1 | style="text-align:center;"| 2.8 | style="text-align:center;"| 2.4 | style="text-align:center;"| 1.4 |- | style="text-align:right;" | <i> Neutralizing</i> | style="text-align:center;"| n/a | style="text-align:center;"| 6.2 | style="text-align:center;"| 2.3 | style="text-align:center;"| 3.0 | style="text-align:center;"| 2.5 | style="text-align:center;"| 1.5 |- | rowspan="7" style="text-align:center;" | <b> Dimensional Obsessive Compulsive Scale (DOCS)</b> | style="text-align:right;" | <i> Total</i> | style="text-align:center;"| n/a | style="text-align:center;"| 31.7 | style="text-align:center;"| 19.0 | style="text-align:center;"| 10.3 | style="text-align:center;"| 8.7 | style="text-align:center;"| 5.3 |- | style="text-align:right;" | <i> Contamination</i> | style="text-align:center;"| n/a | style="text-align:center;"| 7.8 | style="text-align:center;"| 3.4 | style="text-align:center;"| 2.4 | style="text-align:center;"| 2.0 | style="text-align:center;"| 1.2 |- | style="text-align:right;" | <i> Responsibility for Harm</i> | style="text-align:center;"| n/a | style="text-align:center;"| 8.7 | style="text-align:center;"| 4.4 | style="text-align:center;"| 2.4 | style="text-align:center;"| 2.0 | style="text-align:center;"| 1.2 |- | style="text-align:right;" | <i> Unacceptable Thoughts</i> | style="text-align:center;"| n/a | style="text-align:center;"| 9.6 | style="text-align:center;"| 5.4 | style="text-align:center;"| 2.5 | style="text-align:center;"| 2.1 | style="text-align:center;"| 1.3 |- | style="text-align:right;" | <i> Symmetry</i> | style="text-align:center;"| n/a | style="text-align:center;"| 7.9 | style="text-align:center;"| 3.6 | style="text-align:center;"| 2.2 | style="text-align:center;"| 1.8 | style="text-align:center;"| 1.1 |- |} === Process measures === *Quality of Life **Sheehan Disability Scale<ref>Sheehan DV, Harnett-Sheehan K, Raj BA. 1996. The measurement of disability. Int Clin Psychopharmacol 11(Suppl 3): 89–95.</ref> **[http://www.jstor.org/stable/pdf/3765819.pdf?refreqid=excelsior%3A9dcc715f829676edec9bc2c7be1478fa Medical Outcomes Study (MOS) 36-Item Short Form (SF-36) Health Survey]<ref>McHorney, C., Ware, J., & Raczek, A. (1993). The MOS 36-Item Short-Form Health Survey (SF-36): II. Psychometric and Clinical Tests of Validity in Measuring Physical and Mental Health Constructs. ''Medical Care,'' ''31''(3), 247-263. Retrieved from <nowiki>http://www.jstor.org/stable/3765819</nowiki></ref> *Compulsions scale of YBOCS *SUDS Ratings == External Links == *[https://sccap53.org Society of Clinical Child and Adolescent Psychology] *[http://effectivechildtherapy.org/concerns-symptoms-disorders/disorders/self-injurious-thoughts-and-behaviors/ EffectiveChildTherapy.Org information on rule-breaking, defiance, and acting out] *For information on conducting Exposure Therapy for anxiety disordered youth, see [https://www.bravepracticeforkids.com/ www.BravePracticeForKids.com] == References == {{collapse top|Click here for references}} {{Reflist|2|refs= <ref name="EAYfuturedirections"> Youngstrom, E. A. (2013). Future directions in psychological assessment: Combining evidence-based medicine innovations with psychology's historical strengths to enhance utility. Journal of Clinical Child and Adolescent Psychology, 42(1), 139-159. </ref> <ref name="strauss2011"> Strauss, S. E., Glasziou, P., Richardson, W. S., & Haynes, R. B. (2011). Evidence-based medicine: How to practice and teach EBM (4th ed.). New York, NY: Churchill Livingstone. </ref> <ref name="sackett"> Sackett, D. L., Straus, S. E., Richardson, W. S., Rosenberg, W., & Haynes, R. B. (2000). Evidence-based medicine: How to practice and teach EBM. Edinburgh: Churchill Livingstone. </ref> <ref name="RuscioEtAl2010">{{cite journal|last1=Ruscio|first1=AM|last2=Stein|first2=DJ|last3=Chiu|first3=WT|last4=Kessler|first4=RC|title=The epidemiology of obsessive-compulsive disorder in the National Comorbidity Survey Replication.|journal=Molecular psychiatry|date=January 2010|volume=15|issue=1|pages=53-63|pmid=18725912}}</ref> <ref name="KarnoEtAl1988">{{cite journal|last1=Karno|first1=M|last2=Golding|first2=JM|last3=Sorenson|first3=SB|last4=Burnam|first4=MA|title=The epidemiology of obsessive-compulsive disorder in five US communities.|journal=Archives of general psychiatry|date=December 1988|volume=45|issue=12|pages=1094-9|pmid=3264144}}</ref> <ref name="MohammadiEtAl2004">{{cite journal|last1=Mohammadi|first1=MR|last2=Ghanizadeh|first2=A|last3=Rahgozar|first3=M|last4=Noorbala|first4=AA|last5=Davidian|first5=H|last6=Afzali|first6=HM|last7=Naghavi|first7=HR|last8=Yazdi|first8=SA|last9=Saberi|first9=SM|last10=Mesgarpour|first10=B|last11=Akhondzadeh|first11=S|last12=Alaghebandrad|first12=J|last13=Tehranidoost|first13=M|title=Prevalence of obsessive-compulsive disorder in Iran.|journal=BMC psychiatry|date=14 February 2004|volume=4|pages=2|pmid=15018627}}</ref> <ref name="HimleEtAl2008">{{cite journal|last1=Himle|first1=JA|last2=Muroff|first2=JR|last3=Taylor|first3=RJ|last4=Baser|first4=RE|last5=Abelson|first5=JM|last6=Hanna|first6=GL|last7=Abelson|first7=JL|last8=Jackson|first8=JS|title=Obsessive-compulsive disorder among African Americans and blacks of Caribbean descent: results from the National Survey of American Life.|journal=Depression and anxiety|date=2008|volume=25|issue=12|pages=993-1005|pmid=18833577}}</ref> <ref name="SubramaniamEtAl2012">{{cite journal|last1=Subramaniam|first1=M|last2=Abdin|first2=E|last3=Vaingankar|first3=JA|last4=Chong|first4=SA|title=Obsessive--compulsive disorder: prevalence, correlates, help-seeking and quality of life in a multiracial Asian population.|journal=Social psychiatry and psychiatric epidemiology|date=December 2012|volume=47|issue=12|pages=2035-43|pmid=22526825}}</ref> <ref name="LordEtAl2011">{{cite journal|last1=Lord|first1=C|last2=Hall|first2=G|last3=Soares|first3=CN|last4=Steiner|first4=M|title=Physiological stress response in postpartum women with obsessive-compulsive disorder: A pilot study.|journal=Psychoneuroendocrinology|date=January 2011|volume=36|issue=1|pages=133-8|pmid=20537805}}</ref> <ref name="FoaEtAl2002">{{cite journal|last1=Foa|first1=EB|last2=Huppert|first2=JD|last3=Leiberg|first3=S|last4=Langner|first4=R|last5=Kichic|first5=R|last6=Hajcak|first6=G|last7=Salkovskis|first7=PM|title=The Obsessive-Compulsive Inventory: development and validation of a short version.|journal=Psychological assessment|date=December 2002|volume=14|issue=4|pages=485-96|pmid=12501574}}</ref> <ref name="SteketeeEtAl1996">{{cite journal|last1=Steketee|first1=G|last2=Frost|first2=R|last3=Bogart|first3=K|title=The Yale-Brown Obsessive Compulsive Scale: interview versus self-report.|journal=Behaviour research and therapy|date=August 1996|volume=34|issue=8|pages=675-84|pmid=8870295}}</ref> <ref name="AbramowitzDeacon2005">{{cite journal|last1=Abramowitz|first1=Jonathan S.|last2=Deacon|first2=Brett J.|title=Psychometric properties and construct validity of the Obsessive–Compulsive Inventory—Revised: Replication and extension with a clinical sample|journal=Journal of Anxiety Disorders|date=January 2006|volume=20|issue=8|pages=1016–1035|doi=10.1016/j.janxdis.2006.03.001}}</ref> <ref name="AbramowitzEtAl2010">{{cite journal|last1=Abramowitz|first1=JS|last2=Deacon|first2=BJ|last3=Olatunji|first3=BO|last4=Wheaton|first4=MG|last5=Berman|first5=NC|last6=Losardo|first6=D|last7=Timpano|first7=KR|last8=McGrath|first8=PB|last9=Riemann|first9=BC|last10=Adams|first10=T|last11=Björgvinsson|first11=T|last12=Storch|first12=EA|last13=Hale|first13=LR|title=Assessment of obsessive-compulsive symptom dimensions: development and evaluation of the Dimensional Obsessive-Compulsive Scale.|journal=Psychological assessment|date=March 2010|volume=22|issue=1|pages=180-98|pmid=20230164}}</ref> }} {{collapse bottom|Click here for references}} [[Category:Psychological disorder portfolios|{{SUBPAGENAME}}]] d7nnpyz0k838e9q5xeeccq2hm7982eq 2413999 2413997 2022-08-12T19:16:37Z Sophiebirky 2946510 /* Recommended screening instruments */ added time frame for cfoci wikitext text/x-wiki <noinclude>{{Helping Give Away Psychological Science Banner}}</noinclude> {{medical disclaimer}} {{:{{BASEPAGENAME}}/Sidebar}} ==[[Evidence based assessment/Portfolio template/What is a "portfolio"|'''What is a "portfolio"?''']]== For background information on what assessment portfolios are, click the link in the heading above. Want even more information about this topic? There's an extended version of this page [[Evidence-based assessment/Obsessive-compulsive disorder (assessment portfolio)/extended version|here]]. ==[[Evidence based assessment/Preparation phase|'''Preparation phase''']]== === Diagnostic criteria for obsessive-compulsive disorder === {{blockquotetop}}'''ICD-11 Criteria''' <ref>{{Cite web|url=http://apps.who.int/classifications/icd10/browse/2016/en#/F40-F48|title=ICD-10 Version:2016|website=apps.who.int|language=en|accessdate=2018-03-01}}</ref> Obsessive-Compulsive Disorder is characterized by the presence of persistent obsessions or compulsions, or most commonly both. Obsessions are repetitive and persistent thoughts, images, or impulses/urges that are intrusive, unwanted, and are commonly associated with anxiety. The individual attempts to ignore or suppress obsessions or to neutralize them by performing compulsions. Compulsions are repetitive behaviors including repetitive mental acts that the individual feels driven to perform in response to an obsession, according to rigid rules, or to achieve a sense of ‘completeness’. In order for obsessive-compulsive disorder to be diagnosed, obsessions and compulsions must be time consuming (e.g., taking more than an hour per day), and result in significant distress or significant impairment in personal, family, social, educational, occupational or other important areas of functioning. Inclusions *anankastic neurosis *obsessive-compulsive neurosis Exclusions *obsessive compulsive behaviour (MB23.4) '''Changes in DSM-5''' * The diagnostic criteria for obsessive-compulsive disorder changed slightly from DSM-IV-TR to DSM-5. Summaries are available [https://en.wikipedia.org/wiki/DSM-5 here]. {{blockquotebottom}} === Base rates of obsessive-compulsive in different populations and clinical settings=== {| class="wikitable sortable" border="1" |- ! Demography ! Setting ! Base Rate ! Diagnostic Method |- |National (U.S.) adult sample (n=2073)<ref name="RuscioEtAl2010" /> |National Comorbidity Survey Replication |2.3% |World Health Organization Composite International Diagnostic Interview (CIDI 3.0) |- |U.S. household sample (n=18572)<ref name="KarnoEtAl1988" /> |Epidemiological Catchment Area (ECA) Program |1.9-3.3% |Diagnostic Interview Schedule (DIS) |- |Iranian adults (n=25180)<ref name="MohammadiEtAl2004" /> |Iranian population-based study |1.8% |DIS |- |NSAL adult study (n=5191)<ref name="HimleEtAl2008" /> |African-American and Caribbean Households (U.S.) |1.6% |CIDI Short Form |- |Epidemiological sample (n=6616)<ref name="SubramaniamEtAl2012" /> |Singapore Mental Health Study |3.0% |CIDI 3.0 |} '''Search terms:''' [obsessive compulsive disorder OR ocd] AND [prevalence OR incidence] in PsycInfo and PubMed [obsessive compulsive disorder OR ocd] AND [epidemiology] in PsycInfo and PubMed ==[[Evidence based assessment/Prediction phase|'''Prediction phase''']]== ===Recommended screening instruments === The following section contains a list of screening and diagnostic instruments for obsessive-compulsive disorder. {| class="wikitable sortable" border="1" |- ! Screening Instrument ! Format ! Age Range ! Administration Time !Where to Access |- | Children’s Florida Obsessive–Compulsive Inventory (C-FOCI) <ref name=":2">Eric A. Youngstrom, Mitchell J. Prinstein, Eric J. Mash, & Russell A. Barkley. (2020). Assessment of Disorders in Childhood and Adolescence, Fifth Edition: Vol. Fifth edition. The Guilford Press</ref> | Self-report | 7-17 years | 5 minutes |[https://iocdf.org/wp-content/uploads/2014/11/Storch-et-al.-CFOCI-Article.pdf C-FOCI] |- |Obsessive–Compulsive Inventory—Child Version (OCI-CV) <ref name=":2" /> | Self-report | 7-17 years | |[https://pubmed.ncbi.nlm.nih.gov/20171333/ OCI-CV] |- | Children’s Obsessional Compulsive Inventory (CHOCI) <ref name=":2" /> | Self-report | 7-17 years | |[https://www.projectimplicit.net/bethany/papers/ShafranFramptonHeymanReynoldsTeachmanRachman2003.pdf CHOCI] |} === Likelihood ratios and AUCs of screening measures for OCD === * '''''For a list of the likelihood ratios for more broadly reaching screening instruments, [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prediction_phase&wteswitched=1#Likelihood_ratios_and_AUCs_of_common_screening_instruments click here.]''''' {| class="wikitable sortable" border="1" |- ! Screening Measure (Primary Reference) ! Area Under curve (AUC) and Sample Size ! LR+ (Score) ! LR- ! Clinical generalizability !Download Link |- | Y-BOCS-SR<ref name="SteketeeEtAl1996"/> | 0.75 (N=162) | 5.50 (7) | 0.50 | Moderate: OCD among pregnant and postpartum women |[https://static1.squarespace.com/static/58cab82ff5e231f0df8d9cad/t/60945b3af4680c68037f8188/1620335418443/YBOCS-II-SR.pdf Y-BOCS-SR] |- | OCI-R Total<ref name="FoaEtAl2002"/> | 0.81 (N=322) | 3.66 (14) | 0.44 | High: OCD (n=167) versus other anxiety disorders (n=155) at outpatient anxiety clinic |[https://serene.me.uk/tests/oci.pdf OCI-R Total] |- | OCI-R Total<ref name="FoaEtAl2002"/> | 0.82 (N=458) | 2.98 (18) | 0.36 | High: OCD (n=215) versus other anxiety disorders (n=243) at outpatient anxiety clinic |[https://serene.me.uk/tests/oci.pdf OCI-R Total] |- |Brown Assessment of Beliefs Scale<ref name=":1">Eisen, J. L., Phillips, K. A., Baer, L., Beer, D. A., & al, e. (1998). The brown assessment of beliefs scale: Reliability and validity. ''The American Journal of Psychiatry, 155''(1), 102-8. Retrieved from <nowiki>http://libproxy.lib.unc.edu/login?url=https://search.proquest.com/docview/220481418?accountid=14244</nowiki></ref> |(N=50) | | | |[http://www.veale.co.uk/wp-content/uploads/2010/11/BABS_revised_501.pdf BABS] |- |} *“LR+” refers to the change in likelihood ratio associated with a positive test score, and “LR-” is the likelihood ratio for a low score. Likelihood ratios of 1 indicate that the test result did not change impressions at all. LRs larger than 10 or smaller than .10 are frequently clinically decisive; 5 or .20 are helpful, and between 2.0 and .5 are small enough that they rarely result in clinically meaningful changes of formulation (Sackett et al., 2000). ==[[Evidence based assessment/Prescription phase|'''Prescription phase''']]== ===Gold standard diagnostic interviews=== * For a list of broad reaching diagnostic interviews sortable by disorder with PDFs (if applicable), [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prescription_phase&wteswitched=1#Common_Diagnostic_Interviews click here.] ===Recommended diagnostic interviews for OCD=== {| class="wikitable" |+ !Diagnostic Interview !Format !Age Range/ !Administration Time !Where to Access |- | Anxiety Disorders Interview Schedule<ref>Brown, T.A., Di Nardo, P.A., Barlow, D.H., 1994. Anxiety Disorders Interview Schedule for DSM-IV (ADIS-IV-L). Psychological Corporation, San Antonio, TX.</ref> | Semistructured interview | | |[https://www.sciencedirect.com/science/article/abs/pii/S0887618514001510?via%3Dihub ADIS-IV] |- |[https://mfr.osf.io/render?url=https://osf.io/mnzy2/?action=download%26mode=render Yale-Brown Obsessive Compulsive Scale Symptom Checklist]<ref name=":0">{{Cite journal|last=Steketee|first=G|title=The Yale-Brown Obsessive Compulsive Scale: Interview versus self-report|url=http://linkinghub.elsevier.com/retrieve/pii/0005796796000368|journal=Behaviour Research and Therapy|volume=34|issue=8|pages=675–684|doi=10.1016/0005-7967(96)00036-8}}</ref> | Semistructured interview | | Up to 60 mins |[https://www.ohsu.edu/sites/default/files/2019-06/Y-BOCS-Checklist_0.pdf Y-BOCS] |- | [https://search.proquest.com/docview/220481418/abstract/4AF689339CB14A0APQ/1?accountid=14244 Brown Assessment of Beliefs Scale]<ref name=":1">Eisen, J. L., Phillips, K. A., Baer, L., Beer, D. A., & al, e. (1998). The brown assessment of beliefs scale: Reliability and validity. ''The American Journal of Psychiatry, 155''(1), 102-8. Retrieved from <nowiki>http://libproxy.lib.unc.edu/login?url=https://search.proquest.com/docview/220481418?accountid=14244</nowiki></ref> | Semistructured interview | "older children" to adult | |[http://www.veale.co.uk/wp-content/uploads/2010/11/BABS_revised_501.pdf BABS] |- |OCD module of the Structured Clinical Interview for DSM-5 (SCID-5) |Semi-structured interview |18+ | |[https://www.appi.org/products/structured-clinical-interview-for-dsm-5-scid-5 SCID-5] |} ==[[Evidence based assessment/Process phase|'''Process phase''']]== === Treatments === ==== Cognitive behavioral therapy (CBT) and exposure and response prevention (ERP) ==== *Behavior therapy, specifically ERP, has been established as the treatment of choice for OCD <ref>Whittal M.L., McLean P.D., Söchting I., Koch W.J., Taylor S., Anderson K., Paterson R.'''OCD treatment outcome using behavioral and cognitive approaches''' Paper presented at the meeting of the Association for Advancement of Behavior Therapy, Miami Beach, FL (1997)</ref><ref>{{Cite journal|last=Foa|first=Edna B.|last2=Kozak|first2=Michael J.|title=Beyond the efficacy ceiling? Cognitive behavior therapy in search of theory|url=https://doi.org/10.1016/S0005-7894(97)80019-6|journal=Behavior Therapy|volume=28|issue=4|pages=601–611|doi=10.1016/s0005-7894(97)80019-6}}</ref>. *Therapy incorporates ERP and emphasizes cognitive change. **Therapist will help individual identify anxiety-provoking thoughts and situations. **Therapist will develop a treatment plan and idiographic “fear hierarchy.” **Individuals will learn to encounter situations that invoke anxiety without engaging in rituals used to dispel anxiety (ERP). **Exposures will be done gradually at a pace that is comfortable for the client. **Therapy will include homework assignments and is designed to offer lifelong skills. *Therapy includes verbal techniques such as psychoeducation and cognitive restructuring. *Manuals for reference: **The therapist guide: Mastery of Obsessive-Compulsive Disorder: A Cognitive Behavioral Approach<ref>E. Foa, M. Kozak Mastery of obsessive–compulsive disorder: A cognitive-behavioral approach Graywind Publications (1997)</ref> **Cognitive Therapy of Obsessive-Compulsive Disorder: A Guide for Professionals (Wilhelm & Steketee) **Obsessive Compulsive Disorder: Advances in Psychotherapy <ref>{{Cite book|url=https://www.worldcat.org/oclc/70659789|title=Obsessive compulsive disorder|last=S.|first=Abramowitz, Jonathan|date=2006|publisher=Hogrefe & Huber Publishers|isbn=9780889373167|location=Cambridge, MA|oclc=70659789}}</ref> *Treatment alliance is a predictor of subsequent change in OCD symptoms<ref>Keeley, M. L., Geffken, G. R., Ricketts, E., McNamara, J. P., & Storch, E. A. (2011). The therapeutic alliance in the cognitive behavioral treatment of pediatric obsessive–compulsive disorder. ''Journal of Anxiety Disorders'', ''25''(7), 855-863.</ref>. The therapist should provide a “validating and :encouraging” environment so that clients can tolerate the emotional arousal associated with exposures. ==== Medication ==== *Selective serotonin reuptake inhibitors (SSRIs) are commonly used to treat OCD. *These antidepressants include: **[[wikipedia:Fluvoxamine|fluvoxamine]] **[[wikipedia:Fluoxetine|fluoxetine]] **[[wikipedia:Sertraline|sertraline]] **[[wikipedia:Paroxetine|paroxetine]] **[[wikipedia:Citalopram|citalopram]] **[[wikipedia:Clomipramine|clomipramine]] **[[wikipedia:Escitalopram|escitalopram]] **[[wikipedia:Venlafaxine|venlafaxine]] *High doses (relative to doses prescribed for depression) are needed for individuals with OCD. === Process and outcome measures === ==== Clinically significant change benchmarks with common instruments and mood rating scales ==== {| class="wikitable sortable" border="1" |- | rowspan=1" style="text-align:center;font-size:130%;" | <b> Measure</b> | style="text-align:center;font-size:130%;" | <b> Subscale</b> | colspan="3" style="text-align:center;font-size:130%" width="300" | <b> Cut-off scores</b> | colspan="3" style="text-align:center;font-size:120%" | <b> Critical Change <br> (unstandardized scores)</b> |- | colspan="8" span style="font-size:110%; text-align:center;" | <b> Benchmarks Based on Published Norms</b> |- | colspan="2" | | style="text-align:center;font-size:110%" | <b> A</b> | style="text-align:center;font-size:110%" | <b> B</b> | style="text-align:center;font-size:110%" | <b> C</b> | style="text-align:center;font-size:110%" | <b> 95%</b> | style="text-align:center;font-size:110%" | <b> 90%</b> | style="text-align:center;font-size:110%" | <b> SE_difference</b> |- | rowspan="3" style="text-align:center;" | <b> Yale-Brown Obsessive Compulsive Scale (Y-BOCS-SR)</b> | style="text-align:right;" | <i> Total</i> | style="text-align:center;"| 10.6 | style="text-align:center;"| 14.4 | style="text-align:center;"| 12.6 | style="text-align:center;"| 4.7 | style="text-align:center;"| 3.9 | style="text-align:center;"| 2.4 |- | style="text-align:right;" | <i> Obsessions</i> | style="text-align:center;"| 6.6 | style="text-align:center;"| 7.6 | style="text-align:center;"| 7.0 | style="text-align:center;"| 2.5 | style="text-align:center;"| 2.1 | style="text-align:center;"| 1.3 |- | style="text-align:right;" | <i> Compulsions</i> | style="text-align:center;"| 3.5 | style="text-align:center;"| 8.2 | style="text-align:center;"| 6.1 | style="text-align:center;"| 3.6 | style="text-align:center;"| 3.0 | style="text-align:center;"| 1.8 |- | rowspan="7" style="text-align:center;" | <b> Obsessive-Compulsive Inventory – Revised (OCI-R)</b> | style="text-align:right;" | <i> Total</i> | style="text-align:center;"| 1.0 | style="text-align:center;"| 41.0 | style="text-align:center;"| 23.0 | style="text-align:center;"| 14.8 | style="text-align:center;"| 12.5 | style="text-align:center;"| 7.6 |- | style="text-align:right;" | <i> Washing</i> | style="text-align:center;"| n/a | style="text-align:center;"| 7.4 | style="text-align:center;"| 3.1 | style="text-align:center;"| 3.4 | style="text-align:center;"| 2.9 | style="text-align:center;"| 1.7 |- | style="text-align:right;" | <i> Checking</i> | style="text-align:center;"| n/a | style="text-align:center;"| 8.0 | style="text-align:center;"| 3.7 | style="text-align:center;"| 3.0 | style="text-align:center;"| 2.5 | style="text-align:center;"| 1.5 |- | style="text-align:right;" | <i> Ordering</i> | style="text-align:center;"| n/a | style="text-align:center;"| 10.5 | style="text-align:center;"| 4.6 | style="text-align:center;"| 3.1 | style="text-align:center;"| 2.6 | style="text-align:center;"| 1.6 |- | style="text-align:right;" | <i> Obsessing</i> | style="text-align:center;"| n/a | style="text-align:center;"| 8.3 | style="text-align:center;"| 4.7 | style="text-align:center;"| 3.8 | style="text-align:center;"| 3.2 | style="text-align:center;"| 1.9 |- | style="text-align:right;" | <i> Hoarding</i> | style="text-align:center;"| n/a | style="text-align:center;"| 9.8 | style="text-align:center;"| 4.1 | style="text-align:center;"| 2.8 | style="text-align:center;"| 2.4 | style="text-align:center;"| 1.4 |- | style="text-align:right;" | <i> Neutralizing</i> | style="text-align:center;"| n/a | style="text-align:center;"| 6.2 | style="text-align:center;"| 2.3 | style="text-align:center;"| 3.0 | style="text-align:center;"| 2.5 | style="text-align:center;"| 1.5 |- | rowspan="7" style="text-align:center;" | <b> Dimensional Obsessive Compulsive Scale (DOCS)</b> | style="text-align:right;" | <i> Total</i> | style="text-align:center;"| n/a | style="text-align:center;"| 31.7 | style="text-align:center;"| 19.0 | style="text-align:center;"| 10.3 | style="text-align:center;"| 8.7 | style="text-align:center;"| 5.3 |- | style="text-align:right;" | <i> Contamination</i> | style="text-align:center;"| n/a | style="text-align:center;"| 7.8 | style="text-align:center;"| 3.4 | style="text-align:center;"| 2.4 | style="text-align:center;"| 2.0 | style="text-align:center;"| 1.2 |- | style="text-align:right;" | <i> Responsibility for Harm</i> | style="text-align:center;"| n/a | style="text-align:center;"| 8.7 | style="text-align:center;"| 4.4 | style="text-align:center;"| 2.4 | style="text-align:center;"| 2.0 | style="text-align:center;"| 1.2 |- | style="text-align:right;" | <i> Unacceptable Thoughts</i> | style="text-align:center;"| n/a | style="text-align:center;"| 9.6 | style="text-align:center;"| 5.4 | style="text-align:center;"| 2.5 | style="text-align:center;"| 2.1 | style="text-align:center;"| 1.3 |- | style="text-align:right;" | <i> Symmetry</i> | style="text-align:center;"| n/a | style="text-align:center;"| 7.9 | style="text-align:center;"| 3.6 | style="text-align:center;"| 2.2 | style="text-align:center;"| 1.8 | style="text-align:center;"| 1.1 |- |} === Process measures === *Quality of Life **Sheehan Disability Scale<ref>Sheehan DV, Harnett-Sheehan K, Raj BA. 1996. The measurement of disability. Int Clin Psychopharmacol 11(Suppl 3): 89–95.</ref> **[http://www.jstor.org/stable/pdf/3765819.pdf?refreqid=excelsior%3A9dcc715f829676edec9bc2c7be1478fa Medical Outcomes Study (MOS) 36-Item Short Form (SF-36) Health Survey]<ref>McHorney, C., Ware, J., & Raczek, A. (1993). The MOS 36-Item Short-Form Health Survey (SF-36): II. Psychometric and Clinical Tests of Validity in Measuring Physical and Mental Health Constructs. ''Medical Care,'' ''31''(3), 247-263. Retrieved from <nowiki>http://www.jstor.org/stable/3765819</nowiki></ref> *Compulsions scale of YBOCS *SUDS Ratings == External Links == *[https://sccap53.org Society of Clinical Child and Adolescent Psychology] *[http://effectivechildtherapy.org/concerns-symptoms-disorders/disorders/self-injurious-thoughts-and-behaviors/ EffectiveChildTherapy.Org information on rule-breaking, defiance, and acting out] *For information on conducting Exposure Therapy for anxiety disordered youth, see [https://www.bravepracticeforkids.com/ www.BravePracticeForKids.com] == References == {{collapse top|Click here for references}} {{Reflist|2|refs= <ref name="EAYfuturedirections"> Youngstrom, E. A. (2013). Future directions in psychological assessment: Combining evidence-based medicine innovations with psychology's historical strengths to enhance utility. Journal of Clinical Child and Adolescent Psychology, 42(1), 139-159. </ref> <ref name="strauss2011"> Strauss, S. E., Glasziou, P., Richardson, W. S., & Haynes, R. B. (2011). Evidence-based medicine: How to practice and teach EBM (4th ed.). New York, NY: Churchill Livingstone. </ref> <ref name="sackett"> Sackett, D. L., Straus, S. E., Richardson, W. S., Rosenberg, W., & Haynes, R. B. (2000). Evidence-based medicine: How to practice and teach EBM. Edinburgh: Churchill Livingstone. </ref> <ref name="RuscioEtAl2010">{{cite journal|last1=Ruscio|first1=AM|last2=Stein|first2=DJ|last3=Chiu|first3=WT|last4=Kessler|first4=RC|title=The epidemiology of obsessive-compulsive disorder in the National Comorbidity Survey Replication.|journal=Molecular psychiatry|date=January 2010|volume=15|issue=1|pages=53-63|pmid=18725912}}</ref> <ref name="KarnoEtAl1988">{{cite journal|last1=Karno|first1=M|last2=Golding|first2=JM|last3=Sorenson|first3=SB|last4=Burnam|first4=MA|title=The epidemiology of obsessive-compulsive disorder in five US communities.|journal=Archives of general psychiatry|date=December 1988|volume=45|issue=12|pages=1094-9|pmid=3264144}}</ref> <ref name="MohammadiEtAl2004">{{cite journal|last1=Mohammadi|first1=MR|last2=Ghanizadeh|first2=A|last3=Rahgozar|first3=M|last4=Noorbala|first4=AA|last5=Davidian|first5=H|last6=Afzali|first6=HM|last7=Naghavi|first7=HR|last8=Yazdi|first8=SA|last9=Saberi|first9=SM|last10=Mesgarpour|first10=B|last11=Akhondzadeh|first11=S|last12=Alaghebandrad|first12=J|last13=Tehranidoost|first13=M|title=Prevalence of obsessive-compulsive disorder in Iran.|journal=BMC psychiatry|date=14 February 2004|volume=4|pages=2|pmid=15018627}}</ref> <ref name="HimleEtAl2008">{{cite journal|last1=Himle|first1=JA|last2=Muroff|first2=JR|last3=Taylor|first3=RJ|last4=Baser|first4=RE|last5=Abelson|first5=JM|last6=Hanna|first6=GL|last7=Abelson|first7=JL|last8=Jackson|first8=JS|title=Obsessive-compulsive disorder among African Americans and blacks of Caribbean descent: results from the National Survey of American Life.|journal=Depression and anxiety|date=2008|volume=25|issue=12|pages=993-1005|pmid=18833577}}</ref> <ref name="SubramaniamEtAl2012">{{cite journal|last1=Subramaniam|first1=M|last2=Abdin|first2=E|last3=Vaingankar|first3=JA|last4=Chong|first4=SA|title=Obsessive--compulsive disorder: prevalence, correlates, help-seeking and quality of life in a multiracial Asian population.|journal=Social psychiatry and psychiatric epidemiology|date=December 2012|volume=47|issue=12|pages=2035-43|pmid=22526825}}</ref> <ref name="LordEtAl2011">{{cite journal|last1=Lord|first1=C|last2=Hall|first2=G|last3=Soares|first3=CN|last4=Steiner|first4=M|title=Physiological stress response in postpartum women with obsessive-compulsive disorder: A pilot study.|journal=Psychoneuroendocrinology|date=January 2011|volume=36|issue=1|pages=133-8|pmid=20537805}}</ref> <ref name="FoaEtAl2002">{{cite journal|last1=Foa|first1=EB|last2=Huppert|first2=JD|last3=Leiberg|first3=S|last4=Langner|first4=R|last5=Kichic|first5=R|last6=Hajcak|first6=G|last7=Salkovskis|first7=PM|title=The Obsessive-Compulsive Inventory: development and validation of a short version.|journal=Psychological assessment|date=December 2002|volume=14|issue=4|pages=485-96|pmid=12501574}}</ref> <ref name="SteketeeEtAl1996">{{cite journal|last1=Steketee|first1=G|last2=Frost|first2=R|last3=Bogart|first3=K|title=The Yale-Brown Obsessive Compulsive Scale: interview versus self-report.|journal=Behaviour research and therapy|date=August 1996|volume=34|issue=8|pages=675-84|pmid=8870295}}</ref> <ref name="AbramowitzDeacon2005">{{cite journal|last1=Abramowitz|first1=Jonathan S.|last2=Deacon|first2=Brett J.|title=Psychometric properties and construct validity of the Obsessive–Compulsive Inventory—Revised: Replication and extension with a clinical sample|journal=Journal of Anxiety Disorders|date=January 2006|volume=20|issue=8|pages=1016–1035|doi=10.1016/j.janxdis.2006.03.001}}</ref> <ref name="AbramowitzEtAl2010">{{cite journal|last1=Abramowitz|first1=JS|last2=Deacon|first2=BJ|last3=Olatunji|first3=BO|last4=Wheaton|first4=MG|last5=Berman|first5=NC|last6=Losardo|first6=D|last7=Timpano|first7=KR|last8=McGrath|first8=PB|last9=Riemann|first9=BC|last10=Adams|first10=T|last11=Björgvinsson|first11=T|last12=Storch|first12=EA|last13=Hale|first13=LR|title=Assessment of obsessive-compulsive symptom dimensions: development and evaluation of the Dimensional Obsessive-Compulsive Scale.|journal=Psychological assessment|date=March 2010|volume=22|issue=1|pages=180-98|pmid=20230164}}</ref> }} {{collapse bottom|Click here for references}} [[Category:Psychological disorder portfolios|{{SUBPAGENAME}}]] hkpq3qkvcan2kgx49xez4o4eaozhjst 2414000 2413999 2022-08-12T19:23:24Z Sophiebirky 2946510 /* Prescription phase */ added time and age wikitext text/x-wiki <noinclude>{{Helping Give Away Psychological Science Banner}}</noinclude> {{medical disclaimer}} {{:{{BASEPAGENAME}}/Sidebar}} ==[[Evidence based assessment/Portfolio template/What is a "portfolio"|'''What is a "portfolio"?''']]== For background information on what assessment portfolios are, click the link in the heading above. Want even more information about this topic? There's an extended version of this page [[Evidence-based assessment/Obsessive-compulsive disorder (assessment portfolio)/extended version|here]]. ==[[Evidence based assessment/Preparation phase|'''Preparation phase''']]== === Diagnostic criteria for obsessive-compulsive disorder === {{blockquotetop}}'''ICD-11 Criteria''' <ref>{{Cite web|url=http://apps.who.int/classifications/icd10/browse/2016/en#/F40-F48|title=ICD-10 Version:2016|website=apps.who.int|language=en|accessdate=2018-03-01}}</ref> Obsessive-Compulsive Disorder is characterized by the presence of persistent obsessions or compulsions, or most commonly both. Obsessions are repetitive and persistent thoughts, images, or impulses/urges that are intrusive, unwanted, and are commonly associated with anxiety. The individual attempts to ignore or suppress obsessions or to neutralize them by performing compulsions. Compulsions are repetitive behaviors including repetitive mental acts that the individual feels driven to perform in response to an obsession, according to rigid rules, or to achieve a sense of ‘completeness’. In order for obsessive-compulsive disorder to be diagnosed, obsessions and compulsions must be time consuming (e.g., taking more than an hour per day), and result in significant distress or significant impairment in personal, family, social, educational, occupational or other important areas of functioning. Inclusions *anankastic neurosis *obsessive-compulsive neurosis Exclusions *obsessive compulsive behaviour (MB23.4) '''Changes in DSM-5''' * The diagnostic criteria for obsessive-compulsive disorder changed slightly from DSM-IV-TR to DSM-5. Summaries are available [https://en.wikipedia.org/wiki/DSM-5 here]. {{blockquotebottom}} === Base rates of obsessive-compulsive in different populations and clinical settings=== {| class="wikitable sortable" border="1" |- ! Demography ! Setting ! Base Rate ! Diagnostic Method |- |National (U.S.) adult sample (n=2073)<ref name="RuscioEtAl2010" /> |National Comorbidity Survey Replication |2.3% |World Health Organization Composite International Diagnostic Interview (CIDI 3.0) |- |U.S. household sample (n=18572)<ref name="KarnoEtAl1988" /> |Epidemiological Catchment Area (ECA) Program |1.9-3.3% |Diagnostic Interview Schedule (DIS) |- |Iranian adults (n=25180)<ref name="MohammadiEtAl2004" /> |Iranian population-based study |1.8% |DIS |- |NSAL adult study (n=5191)<ref name="HimleEtAl2008" /> |African-American and Caribbean Households (U.S.) |1.6% |CIDI Short Form |- |Epidemiological sample (n=6616)<ref name="SubramaniamEtAl2012" /> |Singapore Mental Health Study |3.0% |CIDI 3.0 |} '''Search terms:''' [obsessive compulsive disorder OR ocd] AND [prevalence OR incidence] in PsycInfo and PubMed [obsessive compulsive disorder OR ocd] AND [epidemiology] in PsycInfo and PubMed ==[[Evidence based assessment/Prediction phase|'''Prediction phase''']]== ===Recommended screening instruments === The following section contains a list of screening and diagnostic instruments for obsessive-compulsive disorder. {| class="wikitable sortable" border="1" |- ! Screening Instrument ! Format ! Age Range ! Administration Time !Where to Access |- | Children’s Florida Obsessive–Compulsive Inventory (C-FOCI) <ref name=":2">Eric A. Youngstrom, Mitchell J. Prinstein, Eric J. Mash, & Russell A. Barkley. (2020). Assessment of Disorders in Childhood and Adolescence, Fifth Edition: Vol. Fifth edition. The Guilford Press</ref> | Self-report | 7-17 years | 5 mins |[https://iocdf.org/wp-content/uploads/2014/11/Storch-et-al.-CFOCI-Article.pdf C-FOCI] |- |Obsessive–Compulsive Inventory—Child Version (OCI-CV) <ref name=":2" /> | Self-report | 7-17 years | |[https://pubmed.ncbi.nlm.nih.gov/20171333/ OCI-CV] |- | Children’s Obsessional Compulsive Inventory (CHOCI) <ref name=":2" /> | Self-report | 7-17 years | |[https://www.projectimplicit.net/bethany/papers/ShafranFramptonHeymanReynoldsTeachmanRachman2003.pdf CHOCI] |} === Likelihood ratios and AUCs of screening measures for OCD === * '''''For a list of the likelihood ratios for more broadly reaching screening instruments, [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prediction_phase&wteswitched=1#Likelihood_ratios_and_AUCs_of_common_screening_instruments click here.]''''' {| class="wikitable sortable" border="1" |- ! Screening Measure (Primary Reference) ! Area Under curve (AUC) and Sample Size ! LR+ (Score) ! LR- ! Clinical generalizability !Download Link |- | Y-BOCS-SR<ref name="SteketeeEtAl1996"/> | 0.75 (N=162) | 5.50 (7) | 0.50 | Moderate: OCD among pregnant and postpartum women |[https://static1.squarespace.com/static/58cab82ff5e231f0df8d9cad/t/60945b3af4680c68037f8188/1620335418443/YBOCS-II-SR.pdf Y-BOCS-SR] |- | OCI-R Total<ref name="FoaEtAl2002"/> | 0.81 (N=322) | 3.66 (14) | 0.44 | High: OCD (n=167) versus other anxiety disorders (n=155) at outpatient anxiety clinic |[https://serene.me.uk/tests/oci.pdf OCI-R Total] |- | OCI-R Total<ref name="FoaEtAl2002"/> | 0.82 (N=458) | 2.98 (18) | 0.36 | High: OCD (n=215) versus other anxiety disorders (n=243) at outpatient anxiety clinic |[https://serene.me.uk/tests/oci.pdf OCI-R Total] |- |Brown Assessment of Beliefs Scale<ref name=":1">Eisen, J. L., Phillips, K. A., Baer, L., Beer, D. A., & al, e. (1998). The brown assessment of beliefs scale: Reliability and validity. ''The American Journal of Psychiatry, 155''(1), 102-8. Retrieved from <nowiki>http://libproxy.lib.unc.edu/login?url=https://search.proquest.com/docview/220481418?accountid=14244</nowiki></ref> |(N=50) | | | |[http://www.veale.co.uk/wp-content/uploads/2010/11/BABS_revised_501.pdf BABS] |- |} *“LR+” refers to the change in likelihood ratio associated with a positive test score, and “LR-” is the likelihood ratio for a low score. Likelihood ratios of 1 indicate that the test result did not change impressions at all. LRs larger than 10 or smaller than .10 are frequently clinically decisive; 5 or .20 are helpful, and between 2.0 and .5 are small enough that they rarely result in clinically meaningful changes of formulation (Sackett et al., 2000). ==[[Evidence based assessment/Prescription phase|'''Prescription phase''']]== ===Gold standard diagnostic interviews=== * For a list of broad reaching diagnostic interviews sortable by disorder with PDFs (if applicable), [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prescription_phase&wteswitched=1#Common_Diagnostic_Interviews click here.] ===Recommended diagnostic interviews for OCD=== {| class="wikitable" |+ !Diagnostic Interview !Format !Age Range/ !Administration Time !Where to Access |- | Anxiety Disorders Interview Schedule<ref>Brown, T.A., Di Nardo, P.A., Barlow, D.H., 1994. Anxiety Disorders Interview Schedule for DSM-IV (ADIS-IV-L). Psychological Corporation, San Antonio, TX.</ref> | Semistructured interview | 6-16 years | 1.5-2 hours |[https://www.sciencedirect.com/science/article/abs/pii/S0887618514001510?via%3Dihub ADIS-IV] |- |[https://mfr.osf.io/render?url=https://osf.io/mnzy2/?action=download%26mode=render Yale-Brown Obsessive Compulsive Scale Symptom Checklist]<ref name=":0">{{Cite journal|last=Steketee|first=G|title=The Yale-Brown Obsessive Compulsive Scale: Interview versus self-report|url=http://linkinghub.elsevier.com/retrieve/pii/0005796796000368|journal=Behaviour Research and Therapy|volume=34|issue=8|pages=675–684|doi=10.1016/0005-7967(96)00036-8}}</ref> | Semistructured interview | 6-17 years | Up to 60 mins |[https://www.ohsu.edu/sites/default/files/2019-06/Y-BOCS-Checklist_0.pdf Y-BOCS] |- | [https://search.proquest.com/docview/220481418/abstract/4AF689339CB14A0APQ/1?accountid=14244 Brown Assessment of Beliefs Scale]<ref name=":1">Eisen, J. L., Phillips, K. A., Baer, L., Beer, D. A., & al, e. (1998). The brown assessment of beliefs scale: Reliability and validity. ''The American Journal of Psychiatry, 155''(1), 102-8. Retrieved from <nowiki>http://libproxy.lib.unc.edu/login?url=https://search.proquest.com/docview/220481418?accountid=14244</nowiki></ref> | Semistructured interview | 16+ years | |[http://www.veale.co.uk/wp-content/uploads/2010/11/BABS_revised_501.pdf BABS] |- |OCD module of the Structured Clinical Interview for DSM-5 (SCID-5) |Semi-structured interview |18+ years |90 mins |[https://www.appi.org/products/structured-clinical-interview-for-dsm-5-scid-5 SCID-5] |} ==[[Evidence based assessment/Process phase|'''Process phase''']]== === Treatments === ==== Cognitive behavioral therapy (CBT) and exposure and response prevention (ERP) ==== *Behavior therapy, specifically ERP, has been established as the treatment of choice for OCD <ref>Whittal M.L., McLean P.D., Söchting I., Koch W.J., Taylor S., Anderson K., Paterson R.'''OCD treatment outcome using behavioral and cognitive approaches''' Paper presented at the meeting of the Association for Advancement of Behavior Therapy, Miami Beach, FL (1997)</ref><ref>{{Cite journal|last=Foa|first=Edna B.|last2=Kozak|first2=Michael J.|title=Beyond the efficacy ceiling? Cognitive behavior therapy in search of theory|url=https://doi.org/10.1016/S0005-7894(97)80019-6|journal=Behavior Therapy|volume=28|issue=4|pages=601–611|doi=10.1016/s0005-7894(97)80019-6}}</ref>. *Therapy incorporates ERP and emphasizes cognitive change. **Therapist will help individual identify anxiety-provoking thoughts and situations. **Therapist will develop a treatment plan and idiographic “fear hierarchy.” **Individuals will learn to encounter situations that invoke anxiety without engaging in rituals used to dispel anxiety (ERP). **Exposures will be done gradually at a pace that is comfortable for the client. **Therapy will include homework assignments and is designed to offer lifelong skills. *Therapy includes verbal techniques such as psychoeducation and cognitive restructuring. *Manuals for reference: **The therapist guide: Mastery of Obsessive-Compulsive Disorder: A Cognitive Behavioral Approach<ref>E. Foa, M. Kozak Mastery of obsessive–compulsive disorder: A cognitive-behavioral approach Graywind Publications (1997)</ref> **Cognitive Therapy of Obsessive-Compulsive Disorder: A Guide for Professionals (Wilhelm & Steketee) **Obsessive Compulsive Disorder: Advances in Psychotherapy <ref>{{Cite book|url=https://www.worldcat.org/oclc/70659789|title=Obsessive compulsive disorder|last=S.|first=Abramowitz, Jonathan|date=2006|publisher=Hogrefe & Huber Publishers|isbn=9780889373167|location=Cambridge, MA|oclc=70659789}}</ref> *Treatment alliance is a predictor of subsequent change in OCD symptoms<ref>Keeley, M. L., Geffken, G. R., Ricketts, E., McNamara, J. P., & Storch, E. A. (2011). The therapeutic alliance in the cognitive behavioral treatment of pediatric obsessive–compulsive disorder. ''Journal of Anxiety Disorders'', ''25''(7), 855-863.</ref>. The therapist should provide a “validating and :encouraging” environment so that clients can tolerate the emotional arousal associated with exposures. ==== Medication ==== *Selective serotonin reuptake inhibitors (SSRIs) are commonly used to treat OCD. *These antidepressants include: **[[wikipedia:Fluvoxamine|fluvoxamine]] **[[wikipedia:Fluoxetine|fluoxetine]] **[[wikipedia:Sertraline|sertraline]] **[[wikipedia:Paroxetine|paroxetine]] **[[wikipedia:Citalopram|citalopram]] **[[wikipedia:Clomipramine|clomipramine]] **[[wikipedia:Escitalopram|escitalopram]] **[[wikipedia:Venlafaxine|venlafaxine]] *High doses (relative to doses prescribed for depression) are needed for individuals with OCD. === Process and outcome measures === ==== Clinically significant change benchmarks with common instruments and mood rating scales ==== {| class="wikitable sortable" border="1" |- | rowspan=1" style="text-align:center;font-size:130%;" | <b> Measure</b> | style="text-align:center;font-size:130%;" | <b> Subscale</b> | colspan="3" style="text-align:center;font-size:130%" width="300" | <b> Cut-off scores</b> | colspan="3" style="text-align:center;font-size:120%" | <b> Critical Change <br> (unstandardized scores)</b> |- | colspan="8" span style="font-size:110%; text-align:center;" | <b> Benchmarks Based on Published Norms</b> |- | colspan="2" | | style="text-align:center;font-size:110%" | <b> A</b> | style="text-align:center;font-size:110%" | <b> B</b> | style="text-align:center;font-size:110%" | <b> C</b> | style="text-align:center;font-size:110%" | <b> 95%</b> | style="text-align:center;font-size:110%" | <b> 90%</b> | style="text-align:center;font-size:110%" | <b> SE_difference</b> |- | rowspan="3" style="text-align:center;" | <b> Yale-Brown Obsessive Compulsive Scale (Y-BOCS-SR)</b> | style="text-align:right;" | <i> Total</i> | style="text-align:center;"| 10.6 | style="text-align:center;"| 14.4 | style="text-align:center;"| 12.6 | style="text-align:center;"| 4.7 | style="text-align:center;"| 3.9 | style="text-align:center;"| 2.4 |- | style="text-align:right;" | <i> Obsessions</i> | style="text-align:center;"| 6.6 | style="text-align:center;"| 7.6 | style="text-align:center;"| 7.0 | style="text-align:center;"| 2.5 | style="text-align:center;"| 2.1 | style="text-align:center;"| 1.3 |- | style="text-align:right;" | <i> Compulsions</i> | style="text-align:center;"| 3.5 | style="text-align:center;"| 8.2 | style="text-align:center;"| 6.1 | style="text-align:center;"| 3.6 | style="text-align:center;"| 3.0 | style="text-align:center;"| 1.8 |- | rowspan="7" style="text-align:center;" | <b> Obsessive-Compulsive Inventory – Revised (OCI-R)</b> | style="text-align:right;" | <i> Total</i> | style="text-align:center;"| 1.0 | style="text-align:center;"| 41.0 | style="text-align:center;"| 23.0 | style="text-align:center;"| 14.8 | style="text-align:center;"| 12.5 | style="text-align:center;"| 7.6 |- | style="text-align:right;" | <i> Washing</i> | style="text-align:center;"| n/a | style="text-align:center;"| 7.4 | style="text-align:center;"| 3.1 | style="text-align:center;"| 3.4 | style="text-align:center;"| 2.9 | style="text-align:center;"| 1.7 |- | style="text-align:right;" | <i> Checking</i> | style="text-align:center;"| n/a | style="text-align:center;"| 8.0 | style="text-align:center;"| 3.7 | style="text-align:center;"| 3.0 | style="text-align:center;"| 2.5 | style="text-align:center;"| 1.5 |- | style="text-align:right;" | <i> Ordering</i> | style="text-align:center;"| n/a | style="text-align:center;"| 10.5 | style="text-align:center;"| 4.6 | style="text-align:center;"| 3.1 | style="text-align:center;"| 2.6 | style="text-align:center;"| 1.6 |- | style="text-align:right;" | <i> Obsessing</i> | style="text-align:center;"| n/a | style="text-align:center;"| 8.3 | style="text-align:center;"| 4.7 | style="text-align:center;"| 3.8 | style="text-align:center;"| 3.2 | style="text-align:center;"| 1.9 |- | style="text-align:right;" | <i> Hoarding</i> | style="text-align:center;"| n/a | style="text-align:center;"| 9.8 | style="text-align:center;"| 4.1 | style="text-align:center;"| 2.8 | style="text-align:center;"| 2.4 | style="text-align:center;"| 1.4 |- | style="text-align:right;" | <i> Neutralizing</i> | style="text-align:center;"| n/a | style="text-align:center;"| 6.2 | style="text-align:center;"| 2.3 | style="text-align:center;"| 3.0 | style="text-align:center;"| 2.5 | style="text-align:center;"| 1.5 |- | rowspan="7" style="text-align:center;" | <b> Dimensional Obsessive Compulsive Scale (DOCS)</b> | style="text-align:right;" | <i> Total</i> | style="text-align:center;"| n/a | style="text-align:center;"| 31.7 | style="text-align:center;"| 19.0 | style="text-align:center;"| 10.3 | style="text-align:center;"| 8.7 | style="text-align:center;"| 5.3 |- | style="text-align:right;" | <i> Contamination</i> | style="text-align:center;"| n/a | style="text-align:center;"| 7.8 | style="text-align:center;"| 3.4 | style="text-align:center;"| 2.4 | style="text-align:center;"| 2.0 | style="text-align:center;"| 1.2 |- | style="text-align:right;" | <i> Responsibility for Harm</i> | style="text-align:center;"| n/a | style="text-align:center;"| 8.7 | style="text-align:center;"| 4.4 | style="text-align:center;"| 2.4 | style="text-align:center;"| 2.0 | style="text-align:center;"| 1.2 |- | style="text-align:right;" | <i> Unacceptable Thoughts</i> | style="text-align:center;"| n/a | style="text-align:center;"| 9.6 | style="text-align:center;"| 5.4 | style="text-align:center;"| 2.5 | style="text-align:center;"| 2.1 | style="text-align:center;"| 1.3 |- | style="text-align:right;" | <i> Symmetry</i> | style="text-align:center;"| n/a | style="text-align:center;"| 7.9 | style="text-align:center;"| 3.6 | style="text-align:center;"| 2.2 | style="text-align:center;"| 1.8 | style="text-align:center;"| 1.1 |- |} === Process measures === *Quality of Life **Sheehan Disability Scale<ref>Sheehan DV, Harnett-Sheehan K, Raj BA. 1996. The measurement of disability. Int Clin Psychopharmacol 11(Suppl 3): 89–95.</ref> **[http://www.jstor.org/stable/pdf/3765819.pdf?refreqid=excelsior%3A9dcc715f829676edec9bc2c7be1478fa Medical Outcomes Study (MOS) 36-Item Short Form (SF-36) Health Survey]<ref>McHorney, C., Ware, J., & Raczek, A. (1993). The MOS 36-Item Short-Form Health Survey (SF-36): II. Psychometric and Clinical Tests of Validity in Measuring Physical and Mental Health Constructs. ''Medical Care,'' ''31''(3), 247-263. Retrieved from <nowiki>http://www.jstor.org/stable/3765819</nowiki></ref> *Compulsions scale of YBOCS *SUDS Ratings == External Links == *[https://sccap53.org Society of Clinical Child and Adolescent Psychology] *[http://effectivechildtherapy.org/concerns-symptoms-disorders/disorders/self-injurious-thoughts-and-behaviors/ EffectiveChildTherapy.Org information on rule-breaking, defiance, and acting out] *For information on conducting Exposure Therapy for anxiety disordered youth, see [https://www.bravepracticeforkids.com/ www.BravePracticeForKids.com] == References == {{collapse top|Click here for references}} {{Reflist|2|refs= <ref name="EAYfuturedirections"> Youngstrom, E. A. (2013). Future directions in psychological assessment: Combining evidence-based medicine innovations with psychology's historical strengths to enhance utility. Journal of Clinical Child and Adolescent Psychology, 42(1), 139-159. </ref> <ref name="strauss2011"> Strauss, S. E., Glasziou, P., Richardson, W. S., & Haynes, R. B. (2011). Evidence-based medicine: How to practice and teach EBM (4th ed.). New York, NY: Churchill Livingstone. </ref> <ref name="sackett"> Sackett, D. L., Straus, S. E., Richardson, W. S., Rosenberg, W., & Haynes, R. B. (2000). Evidence-based medicine: How to practice and teach EBM. Edinburgh: Churchill Livingstone. </ref> <ref name="RuscioEtAl2010">{{cite journal|last1=Ruscio|first1=AM|last2=Stein|first2=DJ|last3=Chiu|first3=WT|last4=Kessler|first4=RC|title=The epidemiology of obsessive-compulsive disorder in the National Comorbidity Survey Replication.|journal=Molecular psychiatry|date=January 2010|volume=15|issue=1|pages=53-63|pmid=18725912}}</ref> <ref name="KarnoEtAl1988">{{cite journal|last1=Karno|first1=M|last2=Golding|first2=JM|last3=Sorenson|first3=SB|last4=Burnam|first4=MA|title=The epidemiology of obsessive-compulsive disorder in five US communities.|journal=Archives of general psychiatry|date=December 1988|volume=45|issue=12|pages=1094-9|pmid=3264144}}</ref> <ref name="MohammadiEtAl2004">{{cite journal|last1=Mohammadi|first1=MR|last2=Ghanizadeh|first2=A|last3=Rahgozar|first3=M|last4=Noorbala|first4=AA|last5=Davidian|first5=H|last6=Afzali|first6=HM|last7=Naghavi|first7=HR|last8=Yazdi|first8=SA|last9=Saberi|first9=SM|last10=Mesgarpour|first10=B|last11=Akhondzadeh|first11=S|last12=Alaghebandrad|first12=J|last13=Tehranidoost|first13=M|title=Prevalence of obsessive-compulsive disorder in Iran.|journal=BMC psychiatry|date=14 February 2004|volume=4|pages=2|pmid=15018627}}</ref> <ref name="HimleEtAl2008">{{cite journal|last1=Himle|first1=JA|last2=Muroff|first2=JR|last3=Taylor|first3=RJ|last4=Baser|first4=RE|last5=Abelson|first5=JM|last6=Hanna|first6=GL|last7=Abelson|first7=JL|last8=Jackson|first8=JS|title=Obsessive-compulsive disorder among African Americans and blacks of Caribbean descent: results from the National Survey of American Life.|journal=Depression and anxiety|date=2008|volume=25|issue=12|pages=993-1005|pmid=18833577}}</ref> <ref name="SubramaniamEtAl2012">{{cite journal|last1=Subramaniam|first1=M|last2=Abdin|first2=E|last3=Vaingankar|first3=JA|last4=Chong|first4=SA|title=Obsessive--compulsive disorder: prevalence, correlates, help-seeking and quality of life in a multiracial Asian population.|journal=Social psychiatry and psychiatric epidemiology|date=December 2012|volume=47|issue=12|pages=2035-43|pmid=22526825}}</ref> <ref name="LordEtAl2011">{{cite journal|last1=Lord|first1=C|last2=Hall|first2=G|last3=Soares|first3=CN|last4=Steiner|first4=M|title=Physiological stress response in postpartum women with obsessive-compulsive disorder: A pilot study.|journal=Psychoneuroendocrinology|date=January 2011|volume=36|issue=1|pages=133-8|pmid=20537805}}</ref> <ref name="FoaEtAl2002">{{cite journal|last1=Foa|first1=EB|last2=Huppert|first2=JD|last3=Leiberg|first3=S|last4=Langner|first4=R|last5=Kichic|first5=R|last6=Hajcak|first6=G|last7=Salkovskis|first7=PM|title=The Obsessive-Compulsive Inventory: development and validation of a short version.|journal=Psychological assessment|date=December 2002|volume=14|issue=4|pages=485-96|pmid=12501574}}</ref> <ref name="SteketeeEtAl1996">{{cite journal|last1=Steketee|first1=G|last2=Frost|first2=R|last3=Bogart|first3=K|title=The Yale-Brown Obsessive Compulsive Scale: interview versus self-report.|journal=Behaviour research and therapy|date=August 1996|volume=34|issue=8|pages=675-84|pmid=8870295}}</ref> <ref name="AbramowitzDeacon2005">{{cite journal|last1=Abramowitz|first1=Jonathan S.|last2=Deacon|first2=Brett J.|title=Psychometric properties and construct validity of the Obsessive–Compulsive Inventory—Revised: Replication and extension with a clinical sample|journal=Journal of Anxiety Disorders|date=January 2006|volume=20|issue=8|pages=1016–1035|doi=10.1016/j.janxdis.2006.03.001}}</ref> <ref name="AbramowitzEtAl2010">{{cite journal|last1=Abramowitz|first1=JS|last2=Deacon|first2=BJ|last3=Olatunji|first3=BO|last4=Wheaton|first4=MG|last5=Berman|first5=NC|last6=Losardo|first6=D|last7=Timpano|first7=KR|last8=McGrath|first8=PB|last9=Riemann|first9=BC|last10=Adams|first10=T|last11=Björgvinsson|first11=T|last12=Storch|first12=EA|last13=Hale|first13=LR|title=Assessment of obsessive-compulsive symptom dimensions: development and evaluation of the Dimensional Obsessive-Compulsive Scale.|journal=Psychological assessment|date=March 2010|volume=22|issue=1|pages=180-98|pmid=20230164}}</ref> }} {{collapse bottom|Click here for references}} [[Category:Psychological disorder portfolios|{{SUBPAGENAME}}]] 14kktv0utb1w2rluqotgtb66bqlabf3 2414001 2414000 2022-08-12T19:25:11Z Sophiebirky 2946510 /* Likelihood ratios and AUCs of screening measures for OCD */ changed n= wikitext text/x-wiki <noinclude>{{Helping Give Away Psychological Science Banner}}</noinclude> {{medical disclaimer}} {{:{{BASEPAGENAME}}/Sidebar}} ==[[Evidence based assessment/Portfolio template/What is a "portfolio"|'''What is a "portfolio"?''']]== For background information on what assessment portfolios are, click the link in the heading above. Want even more information about this topic? There's an extended version of this page [[Evidence-based assessment/Obsessive-compulsive disorder (assessment portfolio)/extended version|here]]. ==[[Evidence based assessment/Preparation phase|'''Preparation phase''']]== === Diagnostic criteria for obsessive-compulsive disorder === {{blockquotetop}}'''ICD-11 Criteria''' <ref>{{Cite web|url=http://apps.who.int/classifications/icd10/browse/2016/en#/F40-F48|title=ICD-10 Version:2016|website=apps.who.int|language=en|accessdate=2018-03-01}}</ref> Obsessive-Compulsive Disorder is characterized by the presence of persistent obsessions or compulsions, or most commonly both. Obsessions are repetitive and persistent thoughts, images, or impulses/urges that are intrusive, unwanted, and are commonly associated with anxiety. The individual attempts to ignore or suppress obsessions or to neutralize them by performing compulsions. Compulsions are repetitive behaviors including repetitive mental acts that the individual feels driven to perform in response to an obsession, according to rigid rules, or to achieve a sense of ‘completeness’. In order for obsessive-compulsive disorder to be diagnosed, obsessions and compulsions must be time consuming (e.g., taking more than an hour per day), and result in significant distress or significant impairment in personal, family, social, educational, occupational or other important areas of functioning. Inclusions *anankastic neurosis *obsessive-compulsive neurosis Exclusions *obsessive compulsive behaviour (MB23.4) '''Changes in DSM-5''' * The diagnostic criteria for obsessive-compulsive disorder changed slightly from DSM-IV-TR to DSM-5. Summaries are available [https://en.wikipedia.org/wiki/DSM-5 here]. {{blockquotebottom}} === Base rates of obsessive-compulsive in different populations and clinical settings=== {| class="wikitable sortable" border="1" |- ! Demography ! Setting ! Base Rate ! Diagnostic Method |- |National (U.S.) adult sample (''n''=2073)<ref name="RuscioEtAl2010" /> |National Comorbidity Survey Replication |2.3% |World Health Organization Composite International Diagnostic Interview (CIDI 3.0) |- |U.S. household sample (''n''=18572)<ref name="KarnoEtAl1988" /> |Epidemiological Catchment Area (ECA) Program |1.9-3.3% |Diagnostic Interview Schedule (DIS) |- |Iranian adults (''n''=25180)<ref name="MohammadiEtAl2004" /> |Iranian population-based study |1.8% |DIS |- |NSAL adult study (''n''=5191)<ref name="HimleEtAl2008" /> |African-American and Caribbean Households (U.S.) |1.6% |CIDI Short Form |- |Epidemiological sample (''n''=6616)<ref name="SubramaniamEtAl2012" /> |Singapore Mental Health Study |3.0% |CIDI 3.0 |} '''Search terms:''' [obsessive compulsive disorder OR ocd] AND [prevalence OR incidence] in PsycInfo and PubMed [obsessive compulsive disorder OR ocd] AND [epidemiology] in PsycInfo and PubMed ==[[Evidence based assessment/Prediction phase|'''Prediction phase''']]== ===Recommended screening instruments === The following section contains a list of screening and diagnostic instruments for obsessive-compulsive disorder. {| class="wikitable sortable" border="1" |- ! Screening Instrument ! Format ! Age Range ! Administration Time !Where to Access |- | Children’s Florida Obsessive–Compulsive Inventory (C-FOCI) <ref name=":2">Eric A. Youngstrom, Mitchell J. Prinstein, Eric J. Mash, & Russell A. Barkley. (2020). Assessment of Disorders in Childhood and Adolescence, Fifth Edition: Vol. Fifth edition. The Guilford Press</ref> | Self-report | 7-17 years | 5 mins |[https://iocdf.org/wp-content/uploads/2014/11/Storch-et-al.-CFOCI-Article.pdf C-FOCI] |- |Obsessive–Compulsive Inventory—Child Version (OCI-CV) <ref name=":2" /> | Self-report | 7-17 years | |[https://pubmed.ncbi.nlm.nih.gov/20171333/ OCI-CV] |- | Children’s Obsessional Compulsive Inventory (CHOCI) <ref name=":2" /> | Self-report | 7-17 years | |[https://www.projectimplicit.net/bethany/papers/ShafranFramptonHeymanReynoldsTeachmanRachman2003.pdf CHOCI] |} === Likelihood ratios and AUCs of screening measures for OCD === * '''''For a list of the likelihood ratios for more broadly reaching screening instruments, [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prediction_phase&wteswitched=1#Likelihood_ratios_and_AUCs_of_common_screening_instruments click here.]''''' {| class="wikitable sortable" border="1" |- ! Screening Measure (Primary Reference) ! Area Under curve (AUC) and Sample Size ! LR+ (Score) ! LR- ! Clinical generalizability !Download Link |- | Y-BOCS-SR<ref name="SteketeeEtAl1996"/> | 0.75 (''n''=162) | 5.50 (7) | 0.50 | Moderate: OCD among pregnant and postpartum women |[https://static1.squarespace.com/static/58cab82ff5e231f0df8d9cad/t/60945b3af4680c68037f8188/1620335418443/YBOCS-II-SR.pdf Y-BOCS-SR] |- | OCI-R Total<ref name="FoaEtAl2002"/> | 0.81 (''n''=322) | 3.66 (14) | 0.44 | High: OCD (''n''=167) versus other anxiety disorders (n=155) at outpatient anxiety clinic |[https://serene.me.uk/tests/oci.pdf OCI-R Total] |- | OCI-R Total<ref name="FoaEtAl2002"/> | 0.82 (''n''=458) | 2.98 (18) | 0.36 | High: OCD (''n''=215) versus other anxiety disorders (n=243) at outpatient anxiety clinic |[https://serene.me.uk/tests/oci.pdf OCI-R Total] |- |Brown Assessment of Beliefs Scale<ref name=":1">Eisen, J. L., Phillips, K. A., Baer, L., Beer, D. A., & al, e. (1998). The brown assessment of beliefs scale: Reliability and validity. ''The American Journal of Psychiatry, 155''(1), 102-8. Retrieved from <nowiki>http://libproxy.lib.unc.edu/login?url=https://search.proquest.com/docview/220481418?accountid=14244</nowiki></ref> |(''n''=50) | | | |[http://www.veale.co.uk/wp-content/uploads/2010/11/BABS_revised_501.pdf BABS] |- |} *“LR+” refers to the change in likelihood ratio associated with a positive test score, and “LR-” is the likelihood ratio for a low score. Likelihood ratios of 1 indicate that the test result did not change impressions at all. LRs larger than 10 or smaller than .10 are frequently clinically decisive; 5 or .20 are helpful, and between 2.0 and .5 are small enough that they rarely result in clinically meaningful changes of formulation (Sackett et al., 2000). ==[[Evidence based assessment/Prescription phase|'''Prescription phase''']]== ===Gold standard diagnostic interviews=== * For a list of broad reaching diagnostic interviews sortable by disorder with PDFs (if applicable), [https://en.wikiversity.org/w/index.php?title=Evidence_based_assessment/Prescription_phase&wteswitched=1#Common_Diagnostic_Interviews click here.] ===Recommended diagnostic interviews for OCD=== {| class="wikitable" |+ !Diagnostic Interview !Format !Age Range/ !Administration Time !Where to Access |- | Anxiety Disorders Interview Schedule<ref>Brown, T.A., Di Nardo, P.A., Barlow, D.H., 1994. Anxiety Disorders Interview Schedule for DSM-IV (ADIS-IV-L). Psychological Corporation, San Antonio, TX.</ref> | Semistructured interview | 6-16 years | 1.5-2 hours |[https://www.sciencedirect.com/science/article/abs/pii/S0887618514001510?via%3Dihub ADIS-IV] |- |[https://mfr.osf.io/render?url=https://osf.io/mnzy2/?action=download%26mode=render Yale-Brown Obsessive Compulsive Scale Symptom Checklist]<ref name=":0">{{Cite journal|last=Steketee|first=G|title=The Yale-Brown Obsessive Compulsive Scale: Interview versus self-report|url=http://linkinghub.elsevier.com/retrieve/pii/0005796796000368|journal=Behaviour Research and Therapy|volume=34|issue=8|pages=675–684|doi=10.1016/0005-7967(96)00036-8}}</ref> | Semistructured interview | 6-17 years | Up to 60 mins |[https://www.ohsu.edu/sites/default/files/2019-06/Y-BOCS-Checklist_0.pdf Y-BOCS] |- | [https://search.proquest.com/docview/220481418/abstract/4AF689339CB14A0APQ/1?accountid=14244 Brown Assessment of Beliefs Scale]<ref name=":1">Eisen, J. L., Phillips, K. A., Baer, L., Beer, D. A., & al, e. (1998). The brown assessment of beliefs scale: Reliability and validity. ''The American Journal of Psychiatry, 155''(1), 102-8. Retrieved from <nowiki>http://libproxy.lib.unc.edu/login?url=https://search.proquest.com/docview/220481418?accountid=14244</nowiki></ref> | Semistructured interview | 16+ years | |[http://www.veale.co.uk/wp-content/uploads/2010/11/BABS_revised_501.pdf BABS] |- |OCD module of the Structured Clinical Interview for DSM-5 (SCID-5) |Semi-structured interview |18+ years |90 mins |[https://www.appi.org/products/structured-clinical-interview-for-dsm-5-scid-5 SCID-5] |} ==[[Evidence based assessment/Process phase|'''Process phase''']]== === Treatments === ==== Cognitive behavioral therapy (CBT) and exposure and response prevention (ERP) ==== *Behavior therapy, specifically ERP, has been established as the treatment of choice for OCD <ref>Whittal M.L., McLean P.D., Söchting I., Koch W.J., Taylor S., Anderson K., Paterson R.'''OCD treatment outcome using behavioral and cognitive approaches''' Paper presented at the meeting of the Association for Advancement of Behavior Therapy, Miami Beach, FL (1997)</ref><ref>{{Cite journal|last=Foa|first=Edna B.|last2=Kozak|first2=Michael J.|title=Beyond the efficacy ceiling? Cognitive behavior therapy in search of theory|url=https://doi.org/10.1016/S0005-7894(97)80019-6|journal=Behavior Therapy|volume=28|issue=4|pages=601–611|doi=10.1016/s0005-7894(97)80019-6}}</ref>. *Therapy incorporates ERP and emphasizes cognitive change. **Therapist will help individual identify anxiety-provoking thoughts and situations. **Therapist will develop a treatment plan and idiographic “fear hierarchy.” **Individuals will learn to encounter situations that invoke anxiety without engaging in rituals used to dispel anxiety (ERP). **Exposures will be done gradually at a pace that is comfortable for the client. **Therapy will include homework assignments and is designed to offer lifelong skills. *Therapy includes verbal techniques such as psychoeducation and cognitive restructuring. *Manuals for reference: **The therapist guide: Mastery of Obsessive-Compulsive Disorder: A Cognitive Behavioral Approach<ref>E. Foa, M. Kozak Mastery of obsessive–compulsive disorder: A cognitive-behavioral approach Graywind Publications (1997)</ref> **Cognitive Therapy of Obsessive-Compulsive Disorder: A Guide for Professionals (Wilhelm & Steketee) **Obsessive Compulsive Disorder: Advances in Psychotherapy <ref>{{Cite book|url=https://www.worldcat.org/oclc/70659789|title=Obsessive compulsive disorder|last=S.|first=Abramowitz, Jonathan|date=2006|publisher=Hogrefe & Huber Publishers|isbn=9780889373167|location=Cambridge, MA|oclc=70659789}}</ref> *Treatment alliance is a predictor of subsequent change in OCD symptoms<ref>Keeley, M. L., Geffken, G. R., Ricketts, E., McNamara, J. P., & Storch, E. A. (2011). The therapeutic alliance in the cognitive behavioral treatment of pediatric obsessive–compulsive disorder. ''Journal of Anxiety Disorders'', ''25''(7), 855-863.</ref>. The therapist should provide a “validating and :encouraging” environment so that clients can tolerate the emotional arousal associated with exposures. ==== Medication ==== *Selective serotonin reuptake inhibitors (SSRIs) are commonly used to treat OCD. *These antidepressants include: **[[wikipedia:Fluvoxamine|fluvoxamine]] **[[wikipedia:Fluoxetine|fluoxetine]] **[[wikipedia:Sertraline|sertraline]] **[[wikipedia:Paroxetine|paroxetine]] **[[wikipedia:Citalopram|citalopram]] **[[wikipedia:Clomipramine|clomipramine]] **[[wikipedia:Escitalopram|escitalopram]] **[[wikipedia:Venlafaxine|venlafaxine]] *High doses (relative to doses prescribed for depression) are needed for individuals with OCD. === Process and outcome measures === ==== Clinically significant change benchmarks with common instruments and mood rating scales ==== {| class="wikitable sortable" border="1" |- | rowspan=1" style="text-align:center;font-size:130%;" | <b> Measure</b> | style="text-align:center;font-size:130%;" | <b> Subscale</b> | colspan="3" style="text-align:center;font-size:130%" width="300" | <b> Cut-off scores</b> | colspan="3" style="text-align:center;font-size:120%" | <b> Critical Change <br> (unstandardized scores)</b> |- | colspan="8" span style="font-size:110%; text-align:center;" | <b> Benchmarks Based on Published Norms</b> |- | colspan="2" | | style="text-align:center;font-size:110%" | <b> A</b> | style="text-align:center;font-size:110%" | <b> B</b> | style="text-align:center;font-size:110%" | <b> C</b> | style="text-align:center;font-size:110%" | <b> 95%</b> | style="text-align:center;font-size:110%" | <b> 90%</b> | style="text-align:center;font-size:110%" | <b> SE_difference</b> |- | rowspan="3" style="text-align:center;" | <b> Yale-Brown Obsessive Compulsive Scale (Y-BOCS-SR)</b> | style="text-align:right;" | <i> Total</i> | style="text-align:center;"| 10.6 | style="text-align:center;"| 14.4 | style="text-align:center;"| 12.6 | style="text-align:center;"| 4.7 | style="text-align:center;"| 3.9 | style="text-align:center;"| 2.4 |- | style="text-align:right;" | <i> Obsessions</i> | style="text-align:center;"| 6.6 | style="text-align:center;"| 7.6 | style="text-align:center;"| 7.0 | style="text-align:center;"| 2.5 | style="text-align:center;"| 2.1 | style="text-align:center;"| 1.3 |- | style="text-align:right;" | <i> Compulsions</i> | style="text-align:center;"| 3.5 | style="text-align:center;"| 8.2 | style="text-align:center;"| 6.1 | style="text-align:center;"| 3.6 | style="text-align:center;"| 3.0 | style="text-align:center;"| 1.8 |- | rowspan="7" style="text-align:center;" | <b> Obsessive-Compulsive Inventory – Revised (OCI-R)</b> | style="text-align:right;" | <i> Total</i> | style="text-align:center;"| 1.0 | style="text-align:center;"| 41.0 | style="text-align:center;"| 23.0 | style="text-align:center;"| 14.8 | style="text-align:center;"| 12.5 | style="text-align:center;"| 7.6 |- | style="text-align:right;" | <i> Washing</i> | style="text-align:center;"| n/a | style="text-align:center;"| 7.4 | style="text-align:center;"| 3.1 | style="text-align:center;"| 3.4 | style="text-align:center;"| 2.9 | style="text-align:center;"| 1.7 |- | style="text-align:right;" | <i> Checking</i> | style="text-align:center;"| n/a | style="text-align:center;"| 8.0 | style="text-align:center;"| 3.7 | style="text-align:center;"| 3.0 | style="text-align:center;"| 2.5 | style="text-align:center;"| 1.5 |- | style="text-align:right;" | <i> Ordering</i> | style="text-align:center;"| n/a | style="text-align:center;"| 10.5 | style="text-align:center;"| 4.6 | style="text-align:center;"| 3.1 | style="text-align:center;"| 2.6 | style="text-align:center;"| 1.6 |- | style="text-align:right;" | <i> Obsessing</i> | style="text-align:center;"| n/a | style="text-align:center;"| 8.3 | style="text-align:center;"| 4.7 | style="text-align:center;"| 3.8 | style="text-align:center;"| 3.2 | style="text-align:center;"| 1.9 |- | style="text-align:right;" | <i> Hoarding</i> | style="text-align:center;"| n/a | style="text-align:center;"| 9.8 | style="text-align:center;"| 4.1 | style="text-align:center;"| 2.8 | style="text-align:center;"| 2.4 | style="text-align:center;"| 1.4 |- | style="text-align:right;" | <i> Neutralizing</i> | style="text-align:center;"| n/a | style="text-align:center;"| 6.2 | style="text-align:center;"| 2.3 | style="text-align:center;"| 3.0 | style="text-align:center;"| 2.5 | style="text-align:center;"| 1.5 |- | rowspan="7" style="text-align:center;" | <b> Dimensional Obsessive Compulsive Scale (DOCS)</b> | style="text-align:right;" | <i> Total</i> | style="text-align:center;"| n/a | style="text-align:center;"| 31.7 | style="text-align:center;"| 19.0 | style="text-align:center;"| 10.3 | style="text-align:center;"| 8.7 | style="text-align:center;"| 5.3 |- | style="text-align:right;" | <i> Contamination</i> | style="text-align:center;"| n/a | style="text-align:center;"| 7.8 | style="text-align:center;"| 3.4 | style="text-align:center;"| 2.4 | style="text-align:center;"| 2.0 | style="text-align:center;"| 1.2 |- | style="text-align:right;" | <i> Responsibility for Harm</i> | style="text-align:center;"| n/a | style="text-align:center;"| 8.7 | style="text-align:center;"| 4.4 | style="text-align:center;"| 2.4 | style="text-align:center;"| 2.0 | style="text-align:center;"| 1.2 |- | style="text-align:right;" | <i> Unacceptable Thoughts</i> | style="text-align:center;"| n/a | style="text-align:center;"| 9.6 | style="text-align:center;"| 5.4 | style="text-align:center;"| 2.5 | style="text-align:center;"| 2.1 | style="text-align:center;"| 1.3 |- | style="text-align:right;" | <i> Symmetry</i> | style="text-align:center;"| n/a | style="text-align:center;"| 7.9 | style="text-align:center;"| 3.6 | style="text-align:center;"| 2.2 | style="text-align:center;"| 1.8 | style="text-align:center;"| 1.1 |- |} === Process measures === *Quality of Life **Sheehan Disability Scale<ref>Sheehan DV, Harnett-Sheehan K, Raj BA. 1996. The measurement of disability. Int Clin Psychopharmacol 11(Suppl 3): 89–95.</ref> **[http://www.jstor.org/stable/pdf/3765819.pdf?refreqid=excelsior%3A9dcc715f829676edec9bc2c7be1478fa Medical Outcomes Study (MOS) 36-Item Short Form (SF-36) Health Survey]<ref>McHorney, C., Ware, J., & Raczek, A. (1993). The MOS 36-Item Short-Form Health Survey (SF-36): II. Psychometric and Clinical Tests of Validity in Measuring Physical and Mental Health Constructs. ''Medical Care,'' ''31''(3), 247-263. Retrieved from <nowiki>http://www.jstor.org/stable/3765819</nowiki></ref> *Compulsions scale of YBOCS *SUDS Ratings == External Links == *[https://sccap53.org Society of Clinical Child and Adolescent Psychology] *[http://effectivechildtherapy.org/concerns-symptoms-disorders/disorders/self-injurious-thoughts-and-behaviors/ EffectiveChildTherapy.Org information on rule-breaking, defiance, and acting out] *For information on conducting Exposure Therapy for anxiety disordered youth, see [https://www.bravepracticeforkids.com/ www.BravePracticeForKids.com] == References == {{collapse top|Click here for references}} {{Reflist|2|refs= <ref name="EAYfuturedirections"> Youngstrom, E. A. (2013). Future directions in psychological assessment: Combining evidence-based medicine innovations with psychology's historical strengths to enhance utility. Journal of Clinical Child and Adolescent Psychology, 42(1), 139-159. </ref> <ref name="strauss2011"> Strauss, S. E., Glasziou, P., Richardson, W. S., & Haynes, R. B. (2011). Evidence-based medicine: How to practice and teach EBM (4th ed.). New York, NY: Churchill Livingstone. </ref> <ref name="sackett"> Sackett, D. L., Straus, S. E., Richardson, W. S., Rosenberg, W., & Haynes, R. B. (2000). Evidence-based medicine: How to practice and teach EBM. Edinburgh: Churchill Livingstone. </ref> <ref name="RuscioEtAl2010">{{cite journal|last1=Ruscio|first1=AM|last2=Stein|first2=DJ|last3=Chiu|first3=WT|last4=Kessler|first4=RC|title=The epidemiology of obsessive-compulsive disorder in the National Comorbidity Survey Replication.|journal=Molecular psychiatry|date=January 2010|volume=15|issue=1|pages=53-63|pmid=18725912}}</ref> <ref name="KarnoEtAl1988">{{cite journal|last1=Karno|first1=M|last2=Golding|first2=JM|last3=Sorenson|first3=SB|last4=Burnam|first4=MA|title=The epidemiology of obsessive-compulsive disorder in five US communities.|journal=Archives of general psychiatry|date=December 1988|volume=45|issue=12|pages=1094-9|pmid=3264144}}</ref> <ref name="MohammadiEtAl2004">{{cite journal|last1=Mohammadi|first1=MR|last2=Ghanizadeh|first2=A|last3=Rahgozar|first3=M|last4=Noorbala|first4=AA|last5=Davidian|first5=H|last6=Afzali|first6=HM|last7=Naghavi|first7=HR|last8=Yazdi|first8=SA|last9=Saberi|first9=SM|last10=Mesgarpour|first10=B|last11=Akhondzadeh|first11=S|last12=Alaghebandrad|first12=J|last13=Tehranidoost|first13=M|title=Prevalence of obsessive-compulsive disorder in Iran.|journal=BMC psychiatry|date=14 February 2004|volume=4|pages=2|pmid=15018627}}</ref> <ref name="HimleEtAl2008">{{cite journal|last1=Himle|first1=JA|last2=Muroff|first2=JR|last3=Taylor|first3=RJ|last4=Baser|first4=RE|last5=Abelson|first5=JM|last6=Hanna|first6=GL|last7=Abelson|first7=JL|last8=Jackson|first8=JS|title=Obsessive-compulsive disorder among African Americans and blacks of Caribbean descent: results from the National Survey of American Life.|journal=Depression and anxiety|date=2008|volume=25|issue=12|pages=993-1005|pmid=18833577}}</ref> <ref name="SubramaniamEtAl2012">{{cite journal|last1=Subramaniam|first1=M|last2=Abdin|first2=E|last3=Vaingankar|first3=JA|last4=Chong|first4=SA|title=Obsessive--compulsive disorder: prevalence, correlates, help-seeking and quality of life in a multiracial Asian population.|journal=Social psychiatry and psychiatric epidemiology|date=December 2012|volume=47|issue=12|pages=2035-43|pmid=22526825}}</ref> <ref name="LordEtAl2011">{{cite journal|last1=Lord|first1=C|last2=Hall|first2=G|last3=Soares|first3=CN|last4=Steiner|first4=M|title=Physiological stress response in postpartum women with obsessive-compulsive disorder: A pilot study.|journal=Psychoneuroendocrinology|date=January 2011|volume=36|issue=1|pages=133-8|pmid=20537805}}</ref> <ref name="FoaEtAl2002">{{cite journal|last1=Foa|first1=EB|last2=Huppert|first2=JD|last3=Leiberg|first3=S|last4=Langner|first4=R|last5=Kichic|first5=R|last6=Hajcak|first6=G|last7=Salkovskis|first7=PM|title=The Obsessive-Compulsive Inventory: development and validation of a short version.|journal=Psychological assessment|date=December 2002|volume=14|issue=4|pages=485-96|pmid=12501574}}</ref> <ref name="SteketeeEtAl1996">{{cite journal|last1=Steketee|first1=G|last2=Frost|first2=R|last3=Bogart|first3=K|title=The Yale-Brown Obsessive Compulsive Scale: interview versus self-report.|journal=Behaviour research and therapy|date=August 1996|volume=34|issue=8|pages=675-84|pmid=8870295}}</ref> <ref name="AbramowitzDeacon2005">{{cite journal|last1=Abramowitz|first1=Jonathan S.|last2=Deacon|first2=Brett J.|title=Psychometric properties and construct validity of the Obsessive–Compulsive Inventory—Revised: Replication and extension with a clinical sample|journal=Journal of Anxiety Disorders|date=January 2006|volume=20|issue=8|pages=1016–1035|doi=10.1016/j.janxdis.2006.03.001}}</ref> <ref name="AbramowitzEtAl2010">{{cite journal|last1=Abramowitz|first1=JS|last2=Deacon|first2=BJ|last3=Olatunji|first3=BO|last4=Wheaton|first4=MG|last5=Berman|first5=NC|last6=Losardo|first6=D|last7=Timpano|first7=KR|last8=McGrath|first8=PB|last9=Riemann|first9=BC|last10=Adams|first10=T|last11=Björgvinsson|first11=T|last12=Storch|first12=EA|last13=Hale|first13=LR|title=Assessment of obsessive-compulsive symptom dimensions: development and evaluation of the Dimensional Obsessive-Compulsive Scale.|journal=Psychological assessment|date=March 2010|volume=22|issue=1|pages=180-98|pmid=20230164}}</ref> }} {{collapse bottom|Click here for references}} [[Category:Psychological disorder portfolios|{{SUBPAGENAME}}]] qztykslmpriissr16uqseydknlcdbq8 0 215858 2414025 2235054 2022-08-13T05:24:48Z Marshallsumter 311529 /* Nova-like remnants */ wikitext text/x-wiki In '''nova-like stars''' the binary system is visible.<ref name=Dous/> These stars exhibit "only irregular small-scale brightness changes or occasional drops in luminosity".<ref name=Dous/> They have accretion disks. "There exist two sub-classes of nova-like stars, the DQ Herculis stars and the AM Herculis stars, whose white dwarfs possess magnetic fields of appreciable strength which dominate the accretion disk and basically all phenomena related to it."<ref name=Dous/> ==DQ Herculis stars== {{main|Stars/DQ Herculis|DQ Herculis stars}} The "DQ Herculis stars [are] cataclysmic variables containing an accreting, magnetic, rapidly rotating white dwarf. These stars are characterized by strong X-ray emission, high-excitation spectra, and very stable optical and X-ray pulsations in their light curves."<ref name=Patterson>{{ cite journal |author=Joseph Patterson |title=The DQ Herculis Stars |journal=Publications of the Astronomical Society of the Pacific |month=March |year=1994 |volume=106 |issue=697 |pages=209-38 |url=http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1994PASP..106..209P |arxiv= |bibcode=1994PASP..106..209P |doi=10.1086/133375 |pmid= |accessdate=2016-10-08 }}</ref> "The white dwarfs' magnetic moments are in the range 10³²-10³⁴ G cm³, slightly weaker than in AM Her stars but with some probable overlap."<ref name=Patterson/> "DQ Hers have broken synchronism [which] is probably [due to] their greater accretion rate and orbital separation."<ref name=Patterson/> "X-ray emission from short-period systems appears to be weaker and softer."<ref name=Patterson/> Studying "the light curve of the remnant of Nova Herculis 1934 (=DQ Herculis), Merle Walker found strictly periodic variations with the amazingly short period of 71 s (Walker 1954, 1956)."<ref name=Patterson/> X-ray source: 2RXP J180730.0+455136 SIMBAD Query : otype='DQ*' lists 49 *s. ===Intermediate polars=== "There are many cataclysmic variables for which there is [...] an increasing number of objects in which magnetic fields do appear to play a role which [...] is sufficient to introduce the classification "intermediate polar"."<ref name=Warner>{{ cite book |author=Brian Warner |title=The Intermediate Polars, In: ''Cataclysmic Variables and Related Objects'' |publisher=Springer |location=Netherlands |year=1983 |editor=Mario Livio and Giora Shaviv |pages=155-172 |url=http://link.springer.com/chapter/10.1007%2F978-94-009-7118-9_20 |arxiv= |bibcode= |doi=10.1007/978-94-009-7118-9_20 |pmid= |isbn=978-94-009-7120-2 |accessdate=2016-10-10 }}</ref> Characteristics include "an X-ray beam emitted from the [slowly] rotating [but asynchronous] degenerate star [which] illuminates either the companion [...] or the gas in the extended hot spot region [...]. Neither of the stars show optical polarization indicating magnetic fields at least an order of magnitude lower than in the polars."<ref name=Warner/> "No positive detection of circular polarization has yet been made in the intermediate polars."<ref name=Warner/> "In the polars, circular polarization is attributed to cyclotron emission from the accretion column [...]."<ref name=Warner/> ===V1033 Cassiopeiae=== X-ray sources: CXOU J002257.6+614107, PBC J0023.0+6138, 1RXS J002258.3+614111, SWIFT J0023.2+6142, 2XMM J002257.7+614107 ===V709 Cassiopeiae=== X-ray source: PBC J0028.9+5917, RX J0028.8+5917, 1RXS J002848.2+591723, SWIFT J0028.9+5917, SWIFT J0028.6+5918 ===XY Arietis=== X-ray source: 1AXG J025609+1926, 2E 677, 2E 0253.3+1914, H0253+193, PBC J0256.1+1925, SWIFT J0256.2+1925, 2XMM J025608.1+192634, XSS J02569+1931 ===GK Persei=== [[Image:GKPersei-MiniSuperNova-20150316.jpg|thumb|right|250px|"Mini Supernova" Explosion Could Have Big Impact. Credit: X-ray: NASA/CXC/RIKEN/D.Takei et al; Optical: NASA/STScI; Radio: NRAO/VLA.]] X-ray source: 1A 0327+43, 3A 0327+438, 2E 785, 2E 0327.7+4344, PBC J0331.1+4353, 1RXS J033111.9+435427, SWIFT J0331.1+4355, SWIFT J0331.2+4354. "Using NASA’s Chandra X-ray Observatory, astronomers [...] pointed the telescope at GK Persei, an object that became a sensation in the astronomical world in 1901 when it suddenly appeared as one of the brightest stars in the sky for a few days, before gradually fading away in brightness."<ref name=Harbaugh>{{ cite web |author=Jennifer Harbaugh |title="Mini Supernova" Explosion Could Have Big Impact |publisher=NASA |location=Washinton, DC USA |date=13 March 2015 |url=http://www.nasa.gov/mission_pages/chandra/mini-supernova-explosion-could-have-big-impact.html |accessdate=2016-10-12 }}</ref> "GK Persei [is] an example of a “classical nova,” an outburst produced by a thermonuclear explosion on the surface of a white dwarf star, the dense remnant of a Sun-like star."<ref name=Harbaugh/> "Chandra first observed GK Persei in February 2000 and then again in November 2013. This 13-year baseline provides astronomers with enough time to notice important differences in the X-ray emission and its properties."<ref name=Harbaugh/> "This new image [on the right] of GK Persei contains X-rays from Chandra (blue), optical data from NASA’s Hubble Space Telescope (yellow), and radio data from the National Science Foundation’s Very Large Array (pink). The X-ray data show hot gas and the radio data show emission from electrons that have been accelerated to high energies by the nova shock wave. The optical data reveal clumps of material that were ejected in the explosion. The nature of the point-like source on the lower left is unknown."<ref name=Harbaugh/> "The X-ray luminosity of the GK Persei remnant decreased by about 40% over the 13 years between the Chandra observations, whereas the temperature of the gas in the remnant has essentially remained constant, at about one million degrees Celsius. As the shock wave expanded and heated an increasing amount of matter, the temperature behind the wave of energy should have decreased. The observed fading and constant temperature suggests that the wave of energy has swept up a negligible amount of gas in the environment around the star over the past 13 years. This suggests that the wave must currently be expanding into a region of much lower density than before, giving clues to stellar neighborhood in which GK Persei resides."<ref name=Harbaugh/> {{clear}} ===V1062 Tauri=== X-ray source: 2E 1206, 2E 0459.4+2441, 1H 0459+248, H0459+246, H 0500+24, PBC J0502.4+2443, SWIFT J0502.4+2446, SWIFT J0502.7+2445, XSS J05019+2444 ===UU Columbae=== X-ray source: RX J0512.2-3241, 1RXS J051214.5-324140 ===TV Columbae=== X-ray sources: 2A0526-328, 3A 0527-329, 1E 0527.5-3251, 2E 1286, 2E 0527.5-3251, A0526-328, 1ES 0527-32.8, 1H 0527-328, PBC J0529.3-3249, 1RXS J052925.8-324858, SWIFT J0529.2-3247, XSS J05295-3252 ===V405 Aurigae=== X-ray sources: 1AXG J055800+5353, 2MAXI J0558+540, PBC J0558.0+5353, RX J0558.0+5353, 1RXS J055800.7+535358, SWIFT J0558.0+5352, SWIFT J0557.8+5353 ===MU Camelopardalis=== X-ray sources: PBC J0625.2+7336, 1RXS J062518.2+733433, SWIFT J0625.1+7336 ===BG Canis Minoris=== The "observations of BG Canis Minoris revealed circular polarization, strongly suggesting the presence of a ~4 x 10⁶ G field (Penning et al. 1986; West et al. 1987). Polarization has also been observed in RE 0751+144 (Pürola et al. 1993)."<ref name=Patterson/> X-ray source: 3A0729+103, 2E 1822, 2E 0728.7+1002, 2MAXI J0730+100, PBC J0731.5+0955, SWIFT J0731.5+0957, SWIFT J0731.4+0954 ===V667 Puppis=== X-ray source: PBC J0732.6-1331, 1RXS J073237.6-133113, SWIFT J073237.6-133109, Swift J0732.5-1331, SWIFT J0732.6-1330 ===PQ Geminorum=== X-ray source: 1AXG J075117+1444, 2MAXI J0751+149, PBC J0751.2+1445, 2RE J075119+144443, 2RE J0751+144, RE0751+14, RE J0751+144, RE J075120+144510, RX J0751.2+1444, SWIFT J0750.9+1439, SWIFT J0751.1+1442, 2XMM J075117.4+144425, XSS J07514+1442 ===HT Camelopardalis=== X-ray source: RX J0757.0+6305, RX J0757.0+6306, 1RXS J075700.5+630602, XSS J08010+6241, [ZEH2003] RX J0757.0+6306 1 ===DO Draconis=== Accordng to SIMBAD, "According to the GCVS team, YY Dra is considered to be another star. Whereas DO Dra is a well-documented dwarf nova, YY Dra is a lost eclipsing binary, which original coordinates are probably erroneous (see discussion in 1987IBVS.3079....1P and 1988IBVS.3154....1K)". X-ray source: 2A 1150+720, 3A1148+719, 1E 1140.8+7158, 1E 1140.7+7158, 2E 2515, 2E 1140.7+7158, 1ES 1140+71.9, 2MAXI J1144+717, PBC J1143.6+7141, RX J1143.6+7141, 1RXS J114338.6+714125, SWIFT J1142.7+7149, XSS J11474+7143, [ZEH2003] RX J1143.6+7141 1. ===V1025 Centauri=== X-ray source: 2MAXI J1237-387, PBC J1238.1-3843, RX J1238-38, RX J1238.2-3842, 1RXS J123816.5-384243, SWIFT J1238.1-3842, XSS J12392-3820. ===EX Hydrae=== X-ray source: 2A 1251-290, 3A 1250-289, 2E 2876, 2E 1249.7-2858, 1ES 1249-28.9, EXO 1249.7-2858, 1H 1251-291, 1M 1252-289, PBC J1252.3-2914, 2RE J125223-291506, 2RE J1252-291, RE J125223-291445, RE J1252-291, RX J1252.4-2914, 1RXS J125224.7-291451, SWIFT J1252.3-2916, 2U 1253-28, 3U 1252-28, 4U1228-29, 4U 1249-28, 2XMM J125224.2-291456, XSS J12529-2911. ===NY Lupi=== X-ray source: PBC J1548.1-4528, 1RXS J154814.5-452845, SWIFT J1548.0-4529, SWIFT J1548.2-4529, 2XMM J154814.4-452839, [KRL2007b] 173. ===V2400 Ophiuchi=== X-ray source: PBC J1712.6-2415, RX J1712.6-2414, 1RXS J171236.3-241445, SWIFT J1712.7-2412, SWIFT J1712.7-2417, 2XMM J171236.3-241445, [KRL2007b] 230. ===V1223 Sagittarii=== X-ray sources: 3A 1851-312, 1ES 1851-31.2, 1H 1853-312, 2MAXI J1854-310, PBC J1854.9-3109, 1RXS J185502.1-310951, SWIFT J1855.0-3110, SWIFT J1854.9-3109, 4U 1849-31, 4U 1851-31, XSS J18553-3111, [KRL2007b] 344. ===V2306 Cygni=== X-ray source: PBC J1958.2+3232, SWIFT J1958.3+3233, 1WGA J1958.2+3232. ===AE Aquarii=== X-ray source: 1AXG J204011-0052, 1E 2037.5-0102, 2E 4404, 2E 2037.5-0102, 1ES 2037-01.0, 1RXS J204009.4-005216, 2XMM J204009.0-005214. ===1RXS J213344.1+510725=== X-ray source: RX J2133.7+5107, 0ES 2132+50.9, PBC J2133.9+5106, 1RXS J213344.1+510725, SWIFT J2133.6+5105, SWIFT J2133.6+5107, 2XMM J213343.5+510723, [KRL2007b] 387. ===FO Aquarii=== X-ray source: 2E 4588, 2E 2215.3-0835, H 2215-086, 2MAXI J2218-083, PBC J2217.9-0820, 1RXS J221753.9-082115, SWIFT J2217.5-0812, 2XMM J221755.3-082103, XSS J22178-0822, [KRL2007b] 394. ===AO Piscium=== X-ray source: 3A 2253-033, 1AXG J225518-0310, 2E 4648, 2E 2252.7-0326, 1H 2251-035, H2252-035, H 2254-033, PBC J2255.3-0310, 1RXS J225518.1-031040, SWIFT J2255.4-0309, XSS J22551-0309. ==AM Herculis stars== {{main|Stars/AM Herculis|AM Herculis stars}} In "the AM Herculis stars, the magnetic field of the white dwarf prevents the formation of an accretion disk.<ref name=Dous/> The "AM Herculis stars [are] additionally characterized by spin-orbit synchronism and the presence of strong circular polarization."<ref name=Patterson/> SIMBAD Query : otype='AM*' lists 95*s. ==Cataclysmic variables== {{main|Stars/Variables/Cataclysmics|Cataclysmic variables}} "The term ''cataclysmic variable'' [..] comprises several related types of objects. For one there are the so-called novae, objects whose brightness has changed by ten to twenty magnitudes once in historical times, or recurrent novae whose amplitudes are on the small side but which have been seen to erupt more often than once; furthermore, dwarf novae whose brightness keeps changing by three to five magnitudes in semi-periodic intervals of time of some ten to one hundred days; and finally nova-like stars, which do not undergo outbursts but only irregular small-scale brightness changes or occasional drops in luminosity, but which in all other aspects are similar to the former group."<ref name=Dous>{{ cite journal |author=C. La Dous |title=Observations and Theory of Cataclysmic Variables: On Progress and Problems in Understanding Dwarf Novae and Nova-Like Stars |journal=Space Science Reviews |month=March |year=1994 |volume=67 |issue=1-2 |pages=1-221 |url=http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994SSRv...67....1L&link_type=ARTICLE&db_key=AST&high=54d6be0a4424362 |arxiv= |bibcode=1994SSRv...67....1L |doi=10.1007/BF00750527 |pmid= |accessdate=2016-09-29 }}</ref> ==Dwarf novas== {{main|Stars/Novas/Dwarfs|Dwarf novas}} In "dwarf novae and nova-like stars the binary system itself is visible, [with] processes which can be traced back directly to the presence of an accretion disk in these systems."<ref name=Dous/> The "primary component of which is a white dwarf."<ref name=Dous/> "The secondary components of cataclysmic variables are cool main sequence stars of spectral type approximately solar of later. Such stars are known to possess fairly active surfaces having large star spots associated with appreciable magnetic activity. Even in single stars the physical structure of such an atmosphere is not well understood, and a consistent theory is still to be developed."<ref name=Dous/> ==Binary stars== {{main|Stars/Binaries|Binary stars}} A nova-like star is a close binary system with a white dwarf as a primary and a "late-type main-sequence secondary" star filling its Roche lobe.<ref name=Dobrzycka/> "The secondary loses mass through the inner Lagrangian point and in order to conserve angular momentum the transferred material usually forms an accretion disk around the white dwarf component. A hot spot originates at the place where the mass-transfer stream impacts the disk."<ref name=Dobrzycka/> In these star systems the degree of magnetic fields ranges from non-magnetic to highly magnetic. "For systems in which the primaries have strong magnetic fields, the process of forming the accretion disk is disturbed. The transferred material is forced to follow the field lines and creates accretion columns near one or both of the white dwarfs magnetic poles."<ref name=Dobrzycka>{{ cite journal |author=Danuta Dobrzycka and Steve B. Howell |title=Spectroscopic observations of the cataclysmic variable PG 0917 + 342 - an ultra short-period nova like system |journal=The Astrophysical Journal |month=April |year=1992 |volume=388 |issue=4 |pages=614-20 |url=http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1992ApJ...388..614D&link_type=ARTICLE&db_key=AST&high=54d6be0a4412709 |arxiv= |bibcode=1992ApJ...388..614D |doi=10.1086/171178 |pmid= |accessdate=2016-09-30 }}</ref> "The shortest orbital periods imply typical dimensions for the systems to be of the order of a solar diameter."<ref name=Dobrzycka/> ==UX Ursae Majoris== "Spectroscopic investigations (Walker and Herbig (1954)) [...] were of sufficiently good quality for the determination of radial velocities [and included] photoelectric measurements [for UX UMa.] But in 1954 the orbital light curve of the old nova DQ Her was solved, and its similarity to that of UX UMa became obvious; its orbital period is shorter by only 5 minutes, and the shape of the eclipse and the hump near to it make the two so similar to one another that one can easily be mistaken for the other (Walker 1954 and 1956)."<ref name=Dous/> As far as long-term brightness changes are concerned, magnetic and non-magnetic nova-like stars behave in the same way.<ref name=Dous/> That the central star in some systems has magnetic properties has nothing to do with the outburst behavior.<ref name=Dous/> A bright accretion disk forms in non-magnetic nova-like stars.<ref name=Kozhevnikov/> Matter swirling along field lines releases energy in magnetic systems.<ref name=Kozhevnikov>{{ cite journal |author=VP Kozhevnikov, PE Zakharova, and TP Nikiforova |title=Short-term brightness variations of V747 Cyg |journal=New Astronomy |month=January |year=2004 |volume=9 |issue=1 |pages=51-7 |url=http://adsabs.harvard.edu/abs/2004NewA....9...51K |arxiv= |bibcode=2004NewA....9...51K |doi=10.1016/S1384-1076(03)00086-1 |pmid= |accessdate=2016-09-30 }}</ref> The evolution of non-magnetic dwarf novae and nova-like stars can be different from the magnetic systems (polars and intermediate polars).<ref name=Ak/> Magnetic and non-magnetic systems display different kinematical properties since some flow velocities come from magnetically channeled plasma.<ref name=Ak>{{ cite journal |author=T Ak T, S Bilir, S Ak, KB Coskunoglu, and Z Eker |title=The age of cataclysmic variables: a kinematic study |journal=New Astronomy |month=August |year=2010 |volume=15 |issue=6 |pages=491-508 |url=http://adsabs.harvard.edu/abs/2010NewA...15..491A |arxiv=0911.3651 |bibcode=2010NewA...15..491A |doi=10.1016/j.newast.2009.11.007 |pmid= |accessdate=2016-09-30 }}</ref> Non-magnetic systems appear to be much more prevalent than magnetic ones, although the number of magnetic systems is small and near the limit of statistical significance when compared to the non-magnetic systems.<ref name=Ak/> X-ray source: J133640.9+515450. According to SIMBAD UX Ursae Majoris is a Nova-like Star, Query : otype='NL*' lists 115 *s. ==Nova-like remnants== {{main|Interstellars/Clouds/Nova-like remnants/Astronomy|Nova-like remnants}} [[Image:V838 Monocerotis expansion.jpg|thumb|right|250px| Successive photos of V838 Monocerotis show the progress of a light echo. Credit: NASA, ESA, H.E. Bond (STScI) and The Hubble Heritage Team (STScI/AURA).{{tlx|free media}}]] "Gas around V838 Monocerotis, nova-like star, seemed to be expanding faster than light from the earth."<ref name=Inaka>{{ cite book |author=Akira Inaka |title=V838 Monoceroti |publisher=Space Telescope |location=Baltimore, Maryland USA |date=2 October 2015 |url=http://www.spacetelescope.org/products/art/akira_inaka_04/ |accessdate=2015-10-07 }}</ref> "This image [on the right] shows a time sequence of Hubble Space Telescope images of the light echo around V838 Mon, taken between May 2002 and [February] 2004. All [five] pictures were taken with Hubble's Advanced Camera for Surveys using filters sensitive to blue, visible, and infrared wavelengths. The apparent expansion of the light echo, as light from the early 2002 outburst of V838 Mon propagates outward into the surrounding dust".<ref name=Levay>{{ cite book |author=Z. Levay |title=Light Continues to Echo Three Years After Stellar Outburst |publisher=Hubblesite |location=Baltimore, Maryland USA |date=3 February 2005 |url=http://hubblesite.org/newscenter/archive/releases/2005/02/image/g/ |accessdate=2015-10-07 }}</ref> "All of the images are shown at the same scale. Moreover, the images are also shown as they would appear for the same exposure times throughout the sequence. Thus the background stars appear constant in brightness, while the surface brightness of the light echo steadily declines. The fading of the light echo is primarily due to the light-scattering properties of interstellar dust. Consider a street lamp on a foggy night. The halo around the lamp is brightest right next to the lamp, while out to the side it is much fainter. Similarly, in the first V838 Mon image, taken in May 2002, the light echo was very bright and compact. At later times, we are seeing dust out to the side of the star, rather than dust that is immediately in front of the star, so the amount of light scattered in our direction is smaller. Hubble astronomers expect the light echo to continue to change its appearance and brightness over the next several years."<ref name=Levay/> {{clear}} ==See also== {{div col|colwidth=20em}} * [[Stars/Novas|Novas]] * [[Stars/Surface fusion|Surface fusion]] * [[Keynote lectures/Supernova X-rays|Supernova X-rays]] {{Div col end}} ==References== {{reflist|2}} ==External links== <!-- footer templates --> {{Stars resources}}{{Sisterlinks|Nova-like stars}} <!-- footer categories --> [[Category:Astrophysics/Lectures]] [[Category:Radiation/Lectures]] [[Category:Radiation astronomy/Lectures]] [[Category:Resources last modified in February 2020]] [[Category:Stars/Lectures]] 6zmnzzhi4g7hvfky04g2pwb4u7dsjoc 2414026 2414025 2022-08-13T05:25:05Z Marshallsumter 311529 /* Nova-like remnants */ wikitext text/x-wiki In '''nova-like stars''' the binary system is visible.<ref name=Dous/> These stars exhibit "only irregular small-scale brightness changes or occasional drops in luminosity".<ref name=Dous/> They have accretion disks. "There exist two sub-classes of nova-like stars, the DQ Herculis stars and the AM Herculis stars, whose white dwarfs possess magnetic fields of appreciable strength which dominate the accretion disk and basically all phenomena related to it."<ref name=Dous/> ==DQ Herculis stars== {{main|Stars/DQ Herculis|DQ Herculis stars}} The "DQ Herculis stars [are] cataclysmic variables containing an accreting, magnetic, rapidly rotating white dwarf. These stars are characterized by strong X-ray emission, high-excitation spectra, and very stable optical and X-ray pulsations in their light curves."<ref name=Patterson>{{ cite journal |author=Joseph Patterson |title=The DQ Herculis Stars |journal=Publications of the Astronomical Society of the Pacific |month=March |year=1994 |volume=106 |issue=697 |pages=209-38 |url=http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1994PASP..106..209P |arxiv= |bibcode=1994PASP..106..209P |doi=10.1086/133375 |pmid= |accessdate=2016-10-08 }}</ref> "The white dwarfs' magnetic moments are in the range 10³²-10³⁴ G cm³, slightly weaker than in AM Her stars but with some probable overlap."<ref name=Patterson/> "DQ Hers have broken synchronism [which] is probably [due to] their greater accretion rate and orbital separation."<ref name=Patterson/> "X-ray emission from short-period systems appears to be weaker and softer."<ref name=Patterson/> Studying "the light curve of the remnant of Nova Herculis 1934 (=DQ Herculis), Merle Walker found strictly periodic variations with the amazingly short period of 71 s (Walker 1954, 1956)."<ref name=Patterson/> X-ray source: 2RXP J180730.0+455136 SIMBAD Query : otype='DQ*' lists 49 *s. ===Intermediate polars=== "There are many cataclysmic variables for which there is [...] an increasing number of objects in which magnetic fields do appear to play a role which [...] is sufficient to introduce the classification "intermediate polar"."<ref name=Warner>{{ cite book |author=Brian Warner |title=The Intermediate Polars, In: ''Cataclysmic Variables and Related Objects'' |publisher=Springer |location=Netherlands |year=1983 |editor=Mario Livio and Giora Shaviv |pages=155-172 |url=http://link.springer.com/chapter/10.1007%2F978-94-009-7118-9_20 |arxiv= |bibcode= |doi=10.1007/978-94-009-7118-9_20 |pmid= |isbn=978-94-009-7120-2 |accessdate=2016-10-10 }}</ref> Characteristics include "an X-ray beam emitted from the [slowly] rotating [but asynchronous] degenerate star [which] illuminates either the companion [...] or the gas in the extended hot spot region [...]. Neither of the stars show optical polarization indicating magnetic fields at least an order of magnitude lower than in the polars."<ref name=Warner/> "No positive detection of circular polarization has yet been made in the intermediate polars."<ref name=Warner/> "In the polars, circular polarization is attributed to cyclotron emission from the accretion column [...]."<ref name=Warner/> ===V1033 Cassiopeiae=== X-ray sources: CXOU J002257.6+614107, PBC J0023.0+6138, 1RXS J002258.3+614111, SWIFT J0023.2+6142, 2XMM J002257.7+614107 ===V709 Cassiopeiae=== X-ray source: PBC J0028.9+5917, RX J0028.8+5917, 1RXS J002848.2+591723, SWIFT J0028.9+5917, SWIFT J0028.6+5918 ===XY Arietis=== X-ray source: 1AXG J025609+1926, 2E 677, 2E 0253.3+1914, H0253+193, PBC J0256.1+1925, SWIFT J0256.2+1925, 2XMM J025608.1+192634, XSS J02569+1931 ===GK Persei=== [[Image:GKPersei-MiniSuperNova-20150316.jpg|thumb|right|250px|"Mini Supernova" Explosion Could Have Big Impact. Credit: X-ray: NASA/CXC/RIKEN/D.Takei et al; Optical: NASA/STScI; Radio: NRAO/VLA.]] X-ray source: 1A 0327+43, 3A 0327+438, 2E 785, 2E 0327.7+4344, PBC J0331.1+4353, 1RXS J033111.9+435427, SWIFT J0331.1+4355, SWIFT J0331.2+4354. "Using NASA’s Chandra X-ray Observatory, astronomers [...] pointed the telescope at GK Persei, an object that became a sensation in the astronomical world in 1901 when it suddenly appeared as one of the brightest stars in the sky for a few days, before gradually fading away in brightness."<ref name=Harbaugh>{{ cite web |author=Jennifer Harbaugh |title="Mini Supernova" Explosion Could Have Big Impact |publisher=NASA |location=Washinton, DC USA |date=13 March 2015 |url=http://www.nasa.gov/mission_pages/chandra/mini-supernova-explosion-could-have-big-impact.html |accessdate=2016-10-12 }}</ref> "GK Persei [is] an example of a “classical nova,” an outburst produced by a thermonuclear explosion on the surface of a white dwarf star, the dense remnant of a Sun-like star."<ref name=Harbaugh/> "Chandra first observed GK Persei in February 2000 and then again in November 2013. This 13-year baseline provides astronomers with enough time to notice important differences in the X-ray emission and its properties."<ref name=Harbaugh/> "This new image [on the right] of GK Persei contains X-rays from Chandra (blue), optical data from NASA’s Hubble Space Telescope (yellow), and radio data from the National Science Foundation’s Very Large Array (pink). The X-ray data show hot gas and the radio data show emission from electrons that have been accelerated to high energies by the nova shock wave. The optical data reveal clumps of material that were ejected in the explosion. The nature of the point-like source on the lower left is unknown."<ref name=Harbaugh/> "The X-ray luminosity of the GK Persei remnant decreased by about 40% over the 13 years between the Chandra observations, whereas the temperature of the gas in the remnant has essentially remained constant, at about one million degrees Celsius. As the shock wave expanded and heated an increasing amount of matter, the temperature behind the wave of energy should have decreased. The observed fading and constant temperature suggests that the wave of energy has swept up a negligible amount of gas in the environment around the star over the past 13 years. This suggests that the wave must currently be expanding into a region of much lower density than before, giving clues to stellar neighborhood in which GK Persei resides."<ref name=Harbaugh/> {{clear}} ===V1062 Tauri=== X-ray source: 2E 1206, 2E 0459.4+2441, 1H 0459+248, H0459+246, H 0500+24, PBC J0502.4+2443, SWIFT J0502.4+2446, SWIFT J0502.7+2445, XSS J05019+2444 ===UU Columbae=== X-ray source: RX J0512.2-3241, 1RXS J051214.5-324140 ===TV Columbae=== X-ray sources: 2A0526-328, 3A 0527-329, 1E 0527.5-3251, 2E 1286, 2E 0527.5-3251, A0526-328, 1ES 0527-32.8, 1H 0527-328, PBC J0529.3-3249, 1RXS J052925.8-324858, SWIFT J0529.2-3247, XSS J05295-3252 ===V405 Aurigae=== X-ray sources: 1AXG J055800+5353, 2MAXI J0558+540, PBC J0558.0+5353, RX J0558.0+5353, 1RXS J055800.7+535358, SWIFT J0558.0+5352, SWIFT J0557.8+5353 ===MU Camelopardalis=== X-ray sources: PBC J0625.2+7336, 1RXS J062518.2+733433, SWIFT J0625.1+7336 ===BG Canis Minoris=== The "observations of BG Canis Minoris revealed circular polarization, strongly suggesting the presence of a ~4 x 10⁶ G field (Penning et al. 1986; West et al. 1987). Polarization has also been observed in RE 0751+144 (Pürola et al. 1993)."<ref name=Patterson/> X-ray source: 3A0729+103, 2E 1822, 2E 0728.7+1002, 2MAXI J0730+100, PBC J0731.5+0955, SWIFT J0731.5+0957, SWIFT J0731.4+0954 ===V667 Puppis=== X-ray source: PBC J0732.6-1331, 1RXS J073237.6-133113, SWIFT J073237.6-133109, Swift J0732.5-1331, SWIFT J0732.6-1330 ===PQ Geminorum=== X-ray source: 1AXG J075117+1444, 2MAXI J0751+149, PBC J0751.2+1445, 2RE J075119+144443, 2RE J0751+144, RE0751+14, RE J0751+144, RE J075120+144510, RX J0751.2+1444, SWIFT J0750.9+1439, SWIFT J0751.1+1442, 2XMM J075117.4+144425, XSS J07514+1442 ===HT Camelopardalis=== X-ray source: RX J0757.0+6305, RX J0757.0+6306, 1RXS J075700.5+630602, XSS J08010+6241, [ZEH2003] RX J0757.0+6306 1 ===DO Draconis=== Accordng to SIMBAD, "According to the GCVS team, YY Dra is considered to be another star. Whereas DO Dra is a well-documented dwarf nova, YY Dra is a lost eclipsing binary, which original coordinates are probably erroneous (see discussion in 1987IBVS.3079....1P and 1988IBVS.3154....1K)". X-ray source: 2A 1150+720, 3A1148+719, 1E 1140.8+7158, 1E 1140.7+7158, 2E 2515, 2E 1140.7+7158, 1ES 1140+71.9, 2MAXI J1144+717, PBC J1143.6+7141, RX J1143.6+7141, 1RXS J114338.6+714125, SWIFT J1142.7+7149, XSS J11474+7143, [ZEH2003] RX J1143.6+7141 1. ===V1025 Centauri=== X-ray source: 2MAXI J1237-387, PBC J1238.1-3843, RX J1238-38, RX J1238.2-3842, 1RXS J123816.5-384243, SWIFT J1238.1-3842, XSS J12392-3820. ===EX Hydrae=== X-ray source: 2A 1251-290, 3A 1250-289, 2E 2876, 2E 1249.7-2858, 1ES 1249-28.9, EXO 1249.7-2858, 1H 1251-291, 1M 1252-289, PBC J1252.3-2914, 2RE J125223-291506, 2RE J1252-291, RE J125223-291445, RE J1252-291, RX J1252.4-2914, 1RXS J125224.7-291451, SWIFT J1252.3-2916, 2U 1253-28, 3U 1252-28, 4U1228-29, 4U 1249-28, 2XMM J125224.2-291456, XSS J12529-2911. ===NY Lupi=== X-ray source: PBC J1548.1-4528, 1RXS J154814.5-452845, SWIFT J1548.0-4529, SWIFT J1548.2-4529, 2XMM J154814.4-452839, [KRL2007b] 173. ===V2400 Ophiuchi=== X-ray source: PBC J1712.6-2415, RX J1712.6-2414, 1RXS J171236.3-241445, SWIFT J1712.7-2412, SWIFT J1712.7-2417, 2XMM J171236.3-241445, [KRL2007b] 230. ===V1223 Sagittarii=== X-ray sources: 3A 1851-312, 1ES 1851-31.2, 1H 1853-312, 2MAXI J1854-310, PBC J1854.9-3109, 1RXS J185502.1-310951, SWIFT J1855.0-3110, SWIFT J1854.9-3109, 4U 1849-31, 4U 1851-31, XSS J18553-3111, [KRL2007b] 344. ===V2306 Cygni=== X-ray source: PBC J1958.2+3232, SWIFT J1958.3+3233, 1WGA J1958.2+3232. ===AE Aquarii=== X-ray source: 1AXG J204011-0052, 1E 2037.5-0102, 2E 4404, 2E 2037.5-0102, 1ES 2037-01.0, 1RXS J204009.4-005216, 2XMM J204009.0-005214. ===1RXS J213344.1+510725=== X-ray source: RX J2133.7+5107, 0ES 2132+50.9, PBC J2133.9+5106, 1RXS J213344.1+510725, SWIFT J2133.6+5105, SWIFT J2133.6+5107, 2XMM J213343.5+510723, [KRL2007b] 387. ===FO Aquarii=== X-ray source: 2E 4588, 2E 2215.3-0835, H 2215-086, 2MAXI J2218-083, PBC J2217.9-0820, 1RXS J221753.9-082115, SWIFT J2217.5-0812, 2XMM J221755.3-082103, XSS J22178-0822, [KRL2007b] 394. ===AO Piscium=== X-ray source: 3A 2253-033, 1AXG J225518-0310, 2E 4648, 2E 2252.7-0326, 1H 2251-035, H2252-035, H 2254-033, PBC J2255.3-0310, 1RXS J225518.1-031040, SWIFT J2255.4-0309, XSS J22551-0309. ==AM Herculis stars== {{main|Stars/AM Herculis|AM Herculis stars}} In "the AM Herculis stars, the magnetic field of the white dwarf prevents the formation of an accretion disk.<ref name=Dous/> The "AM Herculis stars [are] additionally characterized by spin-orbit synchronism and the presence of strong circular polarization."<ref name=Patterson/> SIMBAD Query : otype='AM*' lists 95*s. ==Cataclysmic variables== {{main|Stars/Variables/Cataclysmics|Cataclysmic variables}} "The term ''cataclysmic variable'' [..] comprises several related types of objects. For one there are the so-called novae, objects whose brightness has changed by ten to twenty magnitudes once in historical times, or recurrent novae whose amplitudes are on the small side but which have been seen to erupt more often than once; furthermore, dwarf novae whose brightness keeps changing by three to five magnitudes in semi-periodic intervals of time of some ten to one hundred days; and finally nova-like stars, which do not undergo outbursts but only irregular small-scale brightness changes or occasional drops in luminosity, but which in all other aspects are similar to the former group."<ref name=Dous>{{ cite journal |author=C. La Dous |title=Observations and Theory of Cataclysmic Variables: On Progress and Problems in Understanding Dwarf Novae and Nova-Like Stars |journal=Space Science Reviews |month=March |year=1994 |volume=67 |issue=1-2 |pages=1-221 |url=http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994SSRv...67....1L&link_type=ARTICLE&db_key=AST&high=54d6be0a4424362 |arxiv= |bibcode=1994SSRv...67....1L |doi=10.1007/BF00750527 |pmid= |accessdate=2016-09-29 }}</ref> ==Dwarf novas== {{main|Stars/Novas/Dwarfs|Dwarf novas}} In "dwarf novae and nova-like stars the binary system itself is visible, [with] processes which can be traced back directly to the presence of an accretion disk in these systems."<ref name=Dous/> The "primary component of which is a white dwarf."<ref name=Dous/> "The secondary components of cataclysmic variables are cool main sequence stars of spectral type approximately solar of later. Such stars are known to possess fairly active surfaces having large star spots associated with appreciable magnetic activity. Even in single stars the physical structure of such an atmosphere is not well understood, and a consistent theory is still to be developed."<ref name=Dous/> ==Binary stars== {{main|Stars/Binaries|Binary stars}} A nova-like star is a close binary system with a white dwarf as a primary and a "late-type main-sequence secondary" star filling its Roche lobe.<ref name=Dobrzycka/> "The secondary loses mass through the inner Lagrangian point and in order to conserve angular momentum the transferred material usually forms an accretion disk around the white dwarf component. A hot spot originates at the place where the mass-transfer stream impacts the disk."<ref name=Dobrzycka/> In these star systems the degree of magnetic fields ranges from non-magnetic to highly magnetic. "For systems in which the primaries have strong magnetic fields, the process of forming the accretion disk is disturbed. The transferred material is forced to follow the field lines and creates accretion columns near one or both of the white dwarfs magnetic poles."<ref name=Dobrzycka>{{ cite journal |author=Danuta Dobrzycka and Steve B. Howell |title=Spectroscopic observations of the cataclysmic variable PG 0917 + 342 - an ultra short-period nova like system |journal=The Astrophysical Journal |month=April |year=1992 |volume=388 |issue=4 |pages=614-20 |url=http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1992ApJ...388..614D&link_type=ARTICLE&db_key=AST&high=54d6be0a4412709 |arxiv= |bibcode=1992ApJ...388..614D |doi=10.1086/171178 |pmid= |accessdate=2016-09-30 }}</ref> "The shortest orbital periods imply typical dimensions for the systems to be of the order of a solar diameter."<ref name=Dobrzycka/> ==UX Ursae Majoris== "Spectroscopic investigations (Walker and Herbig (1954)) [...] were of sufficiently good quality for the determination of radial velocities [and included] photoelectric measurements [for UX UMa.] But in 1954 the orbital light curve of the old nova DQ Her was solved, and its similarity to that of UX UMa became obvious; its orbital period is shorter by only 5 minutes, and the shape of the eclipse and the hump near to it make the two so similar to one another that one can easily be mistaken for the other (Walker 1954 and 1956)."<ref name=Dous/> As far as long-term brightness changes are concerned, magnetic and non-magnetic nova-like stars behave in the same way.<ref name=Dous/> That the central star in some systems has magnetic properties has nothing to do with the outburst behavior.<ref name=Dous/> A bright accretion disk forms in non-magnetic nova-like stars.<ref name=Kozhevnikov/> Matter swirling along field lines releases energy in magnetic systems.<ref name=Kozhevnikov>{{ cite journal |author=VP Kozhevnikov, PE Zakharova, and TP Nikiforova |title=Short-term brightness variations of V747 Cyg |journal=New Astronomy |month=January |year=2004 |volume=9 |issue=1 |pages=51-7 |url=http://adsabs.harvard.edu/abs/2004NewA....9...51K |arxiv= |bibcode=2004NewA....9...51K |doi=10.1016/S1384-1076(03)00086-1 |pmid= |accessdate=2016-09-30 }}</ref> The evolution of non-magnetic dwarf novae and nova-like stars can be different from the magnetic systems (polars and intermediate polars).<ref name=Ak/> Magnetic and non-magnetic systems display different kinematical properties since some flow velocities come from magnetically channeled plasma.<ref name=Ak>{{ cite journal |author=T Ak T, S Bilir, S Ak, KB Coskunoglu, and Z Eker |title=The age of cataclysmic variables: a kinematic study |journal=New Astronomy |month=August |year=2010 |volume=15 |issue=6 |pages=491-508 |url=http://adsabs.harvard.edu/abs/2010NewA...15..491A |arxiv=0911.3651 |bibcode=2010NewA...15..491A |doi=10.1016/j.newast.2009.11.007 |pmid= |accessdate=2016-09-30 }}</ref> Non-magnetic systems appear to be much more prevalent than magnetic ones, although the number of magnetic systems is small and near the limit of statistical significance when compared to the non-magnetic systems.<ref name=Ak/> X-ray source: J133640.9+515450. According to SIMBAD UX Ursae Majoris is a Nova-like Star, Query : otype='NL*' lists 115 *s. ==Nova-like remnants== [[Image:V838 Monocerotis expansion.jpg|thumb|right|250px| Successive photos of V838 Monocerotis show the progress of a light echo. Credit: NASA, ESA, H.E. Bond (STScI) and The Hubble Heritage Team (STScI/AURA).{{tlx|free media}}]] "Gas around V838 Monocerotis, nova-like star, seemed to be expanding faster than light from the earth."<ref name=Inaka>{{ cite book |author=Akira Inaka |title=V838 Monoceroti |publisher=Space Telescope |location=Baltimore, Maryland USA |date=2 October 2015 |url=http://www.spacetelescope.org/products/art/akira_inaka_04/ |accessdate=2015-10-07 }}</ref> "This image [on the right] shows a time sequence of Hubble Space Telescope images of the light echo around V838 Mon, taken between May 2002 and [February] 2004. All [five] pictures were taken with Hubble's Advanced Camera for Surveys using filters sensitive to blue, visible, and infrared wavelengths. The apparent expansion of the light echo, as light from the early 2002 outburst of V838 Mon propagates outward into the surrounding dust".<ref name=Levay>{{ cite book |author=Z. Levay |title=Light Continues to Echo Three Years After Stellar Outburst |publisher=Hubblesite |location=Baltimore, Maryland USA |date=3 February 2005 |url=http://hubblesite.org/newscenter/archive/releases/2005/02/image/g/ |accessdate=2015-10-07 }}</ref> "All of the images are shown at the same scale. Moreover, the images are also shown as they would appear for the same exposure times throughout the sequence. Thus the background stars appear constant in brightness, while the surface brightness of the light echo steadily declines. The fading of the light echo is primarily due to the light-scattering properties of interstellar dust. Consider a street lamp on a foggy night. The halo around the lamp is brightest right next to the lamp, while out to the side it is much fainter. Similarly, in the first V838 Mon image, taken in May 2002, the light echo was very bright and compact. At later times, we are seeing dust out to the side of the star, rather than dust that is immediately in front of the star, so the amount of light scattered in our direction is smaller. Hubble astronomers expect the light echo to continue to change its appearance and brightness over the next several years."<ref name=Levay/> {{clear}} ==See also== {{div col|colwidth=20em}} * [[Stars/Novas|Novas]] * [[Stars/Surface fusion|Surface fusion]] * [[Keynote lectures/Supernova X-rays|Supernova X-rays]] {{Div col end}} ==References== {{reflist|2}} ==External links== <!-- footer templates --> {{Stars resources}}{{Sisterlinks|Nova-like stars}} <!-- footer categories --> [[Category:Astrophysics/Lectures]] [[Category:Radiation/Lectures]] [[Category:Radiation astronomy/Lectures]] [[Category:Resources last modified in February 2020]] [[Category:Stars/Lectures]] 5gizoe2pzva6cs3cnm90tu08piu1m52 0 216863 2414028 2399437 2022-08-13T05:57:12Z Marshallsumter 311529 /* Soft X-rays */ wikitext text/x-wiki [[Image:Glowing Stellar Nurseries.jpg|thumb|right|250px|This is a colour composite image of RCW120. Credit: ESO/APEX/DSS2/ SuperCosmos/ Deharveng(LAM)/ Zavagno(LAM).{{tlx|free media}}]] Radiation astronomy is often performed using electromagnetics. Electromagnetics are most familiar as light, or electromagnetic radiation. The image at right is a colour "composite image of RCW120. It reveals how an expanding bubble of ionised gas about ten light-years across is causing the surrounding material to collapse into dense clumps where new stars are then formed. The 870-micron submillimetre-wavelength data were taken with the LABOCA camera on the 12-m Atacama Pathfinder Experiment (APEX) telescope. Here, the submillimetre emission is shown as the blue clouds surrounding the reddish glow of the ionised gas (shown with data from the SuperCosmos H-alpha survey). The image also contains data from the Second Generation Digitized Sky Survey (I-band shown in blue, R-band shown in red)."<ref name="Deharveng">{{cite book |author= Deharveng |title=Glowing Stellar Nurseries |publisher=European Southern Observatory |location= |date=November 11, 2008 |url=http://www.eso.org/public/images/eso0840a/ |accessdate=2014-03-13 }}</ref> '''Electromagnetic radiation astronomy''' is a broader concept physics subject heading used by the American Physical Society (APS).<ref name=APS>{{ cite book |author=APS |title=Physics Subject Headings |publisher=American Physical Society |location=College Park, MD |date= |editor= |pages= |url=https://physh.aps.org/concepts/893ecc24-c678-4687-bd3a-0b4a1bcb4cfc |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2018-01-08 }}</ref> {{clear}} ==Gamma rays== {{main|Radiation astronomy/Gamma rays|Gamma-ray astronomy}} [[Image:Gamma-Ray Quasar 3C 279.jpg|thumb|right|250px|This is an image of quasar 3C 279 in gamma rays. Credit: NASA EGRET Compton observatory team.]] '''Def.''' very high [[wikt:frequence|frequency]] (and therefore very high [[wikt:energy|energy]]) [[wikt:electromagnetic radiation|electromagnetic radiation]] emitted as a [[wikt:consequence|consequence]] of [[wikt:radioactivity|radioactivity]] is called a '''gamma ray'''. '''Def.''' electromagnetic radiation consisting of gamma rays is called '''gamma radiation'''. Gamma rays typically have frequencies above 10 [[w:Hertz|exahertz]] (or >10¹⁹ Hz), and therefore have energies above 100 [[w:electronvolt|keV]] and wavelengths less than 10 [[w:picometer|picometer]]s (less than the diameter of an [[w:atom|atom]]). However, this is not a hard and fast definition, but rather only a rule-of-thumb description for natural processes. Gamma rays from [[w:radioactive decay|radioactive decay]] are defined as gamma rays no matter what their energy, so that there is no ''lower'' limit to gamma energy derived from radioactive decay. Gamma decay commonly produces energies of a few hundred [[w:keV|keV]], and almost always less than 10 [[w:MeV|MeV]]. In astronomy, gamma rays are defined by their energy, and no production process need be specified. The energies of gamma rays from astronomical sources range over 10 TeV, at a level far too large to result from radioactive decay. A notable example is extremely powerful bursts of high-energy radiation normally referred to as long duration [[w:gamma-ray burst|gamma-ray burst]]s, which produce gamma rays by a mechanism not compatible with radioactive decay. "The unusually wide span of the gamma-ray spectral window [covers] at least ten decades of photon energies (~10⁵ - 10¹⁵ eV)".<ref name=Bhat>{{ cite journal |author=C. L. Bhat |title=Ground-based γ-ray astronomy : Present status and future prospects |journal=Bulletin of the Astronomical Society of India |month=December |year=1997 |volume=25 |issue=12 |pages=461-84 |url= |arxiv= |bibcode=1997BASI...25..461B |doi= |pmid= |accessdate=2013-05-10 }}</ref> The [[w:Rosemary Hill Observatory|Rosemary Hill Observatory]] (RHO) started observing 3C 279 in 1971,<ref name=Webb>{{ cite journal |author=J. R. Webb, M. T. Carini, S. Clements, S. Fajardo, P. P. Gombola, R. J. Leacock, A. C. Sadun, A. G. Smith |title=The 1987-1990 optical outburst of the OVV quasar 3C 279 |journal=Astronomical Journal |year=1990 |volume=100 |pages=1452–6 |bibcode=1990AJ....100.1452W |doi=10.1086/115609 }}</ref> and was further observed by the [[w:Compton Gamma Ray Observatory|Compton Gamma Ray Observatory]] in 1991, when it was unexpectedly discovered to be one of the brightest gamma ray objects in the sky.<ref name=APOD>[http://antwrp.gsfc.nasa.gov/apod/ap981226.html APOD: December 26, 1998 - Gamma Ray Quasar]</ref> It is also one of the most bright and variable sources in the gamma ray sky monitored by the [[w:Fermi Space Telescope|Fermi Space Telescope]]. Apparent [[w:Superluminal#Astronomical observations|superluminal motion]] was detected during observations first made in 1973 in a jet of material departing from the quasar, though it should be understood that this effect is an optical illusion caused by naive estimations of the speed, and no truly superluminal motion is occurring.<ref>[http://www.spacetimetravel.org/bewegung/bewegung4.html Apparent superluminal motion]</ref> Markarian (Mrk) 1501 is the first Seyfert I galaxy to have superluminal motion.<ref name=Brunthaler>{{ cite journal |author=A. Brunthaler, H. Falcke, G.C. Bower, M.F. Aller, H.D. Aller, H. Teräsranta, A.P. Lobanov, T.P. Krichbaum, and A.R. Patnaik |title=II Zw 2, the first superluminal jet in a Seyfert galaxy |journal=Astronomy and Astrophysics |month=May |year=2000 |volume=357 |issue= |pages=L45-8 |url= |arxiv=astro-ph/0004256 |bibcode=2000A&A...357L..45B |doi= |pmid= |accessdate=2013-05-09 }}</ref> Mrk 1501 is an ultraviolet, X-ray, and gamma-ray source. {{clear}} ==Hard gamma rays== {{main|Radiation astronomy/Gamma rays}} [[Image:IC 310 hard gamma rays.png|thumb|center|400px|Emergence of IC 310 is captured in a series of images. Credit: A. Neronov et al. and NASA/DOE/LAT collaboration.]] "Fermi's Large Area Telescope (LAT) scans the entire sky every three hours, continually deepening its portrait of the sky in gamma rays, the most energetic form of light. While the energy of visible light falls between about 2 and 3 electron volts, the LAT detects gamma rays with energies ranging from 20 million to more than 300 billion electron volts (GeV)."<ref name=Perrotto>{{ cite book |author=Trent J. Perrotto |title=NASA's Fermi Space Telescope Explores New Energy Extremes |publisher=NASA |location=Washington, DC USA |date=10 January 2012 |url=http://www.nasa.gov/mission_pages/GLAST/news/energy-extremes.html |accessdate=3 November 2016}}</ref> "At higher energies, gamma rays are rare. Above 10 GeV, even Fermi's LAT detects only one gamma ray every four months from some sources."<ref name=Perrotto/> "Any object producing gamma rays at these energies is undergoing extraordinary astrophysical processes. More than half of the 496 sources [the Fermi hard-source list] in the new census are active galaxies, where matter falling into a supermassive black hole powers jets that spray out particles at nearly the speed of light."<ref name=Perrotto/> "One example is the well-known radio galaxy NGC 1275 [above left], which is a bright, isolated source below 10 GeV. At higher energies it fades appreciably and another nearby source begins to appear. Above 100 GeV, NGC 1275 becomes undetectable by Fermi, while the new source, the radio galaxy IC 310, shines brightly."<ref name=Perrotto/> "The catalog serves as an important roadmap for ground-based facilities called Atmospheric Cherenkov Telescopes, which have amassed about 130 gamma-ray sources with energies above 100 GeV. They include the Major Atmospheric Gamma Imaging Cherenkov telescope (MAGIC) on La Palma in the Canary Islands, the Very Energetic Radiation Imaging Telescope Array System (VERITAS) in Arizona, and the High Energy Stereoscopic System (H.E.S.S.) in Namibia."<ref name=Perrotto/> {{clear}} ==Soft gamma rays== [[Image:7107.tnl.jpg|thumb|right|250px|A view of 4C 71.07 from observations by the Burst and Transient Source Experiment. Credit: Mike McCollough, USRA.]] On the right is a "view of 4C 71.07 from observations by the Burst and Transient Source Experiment. This helped convince scientists that they were studying data from the quasar and not some other source in the neighborhood."<ref name=Horack>{{ cite book |author=John M. Horack |title=BATSE finds most distant quasar yet seen in soft gamma rays |publisher=NASA |location=Washington, DC USA |date=18 November 1999 |url=http://science1.nasa.gov/science-news/science-at-nasa/1999/ast24nov99_1/ |accessdate=3 November 2016 }}</ref> "Angela [Malizia] has now discovered this quasar in soft gamma rays."<ref name=McCollough>{{ cite book |author=Mike McCollough |title=BATSE finds most distant quasar yet seen in soft gamma rays |publisher=NASA |location=Washington, DC USA |date=18 November 1999 |url=http://science1.nasa.gov/science-news/science-at-nasa/1999/ast24nov99_1/ |accessdate=3 November 2016 }}</ref> "It is also known as QSO 0836+710, a quasar or quasi-stellar object that emits baffling amounts of radio energy. (The numbers actually designate the same place in the sky: 71.07 is its declination, and 0836+710 is right ascension and declination.)"<ref name=Horack/> "It's basically the nucleus of a galaxy that is showing extraordinary activity."<ref name=McCollough/> "What BATSE has discovered is that it can be a soft gamma-ray source."<ref name=McCollough/> "This makes it the faintest and most distant object to be observed in soft gamma rays. 4C 71.07 has already been observed in gamma rays by the Energetic Gamma Ray Telescope (EGRET) also aboard the Compton Gamma Ray Observatory."<ref name=Horack/> "In the case of 4C 71.07, it's the brightest AGN seen above 20,000 electron volts (20 keV). Its average flux (the amount of radiation reaching our telescopes) is about 13 milliCrabs, or 13/1,000ths as much as the Crab Nebula, a standard candle in astrophysics."<ref name=Horack/> {{clear}} ==X-rays== {{main|Radiation astronomy/X-rays}} [[Image:PIA02118.jpg|right|thumb|250px|This false-color image shows comet Tempel 1 as seen by Chandra X-ray Observatory on June 30, 2005, Universal Time. Credit: NASA/JPL-Caltech/UMD.]] '''Def.''' an action or process of throwing or sending out a traveling X-ray in a line, beam, or stream of small cross section is called '''X-radiation'''. X-rays span 3 decades in wavelength, frequency and energy. Although the more energetic X-rays, photons with an energy greater than 30 keV (4,800 aJ) can penetrate the air at least for distances of a few meters (they would never have been detected and medical X-ray machines would not work if this was not the case) the Earth's atmosphere is thick enough that virtually none are able to penetrate from outer space all the way to the Earth's surface. X-rays in the 0.5 to 5 keV (80 to 800 aJ) range, where most celestial sources give off the bulk of their energy, can be stopped by a few sheets of paper; ninety percent of the photons in a beam of 3 keV (480 aJ) X-rays are absorbed by traveling through just 10 cm of air. The X-rays observed from comets such as Tempel 1 on the right are caused by an interaction between highly charged oxygen in the solar wind and neutral gases from the comet. {{clear}} ==Hard X-rays== [[Image:Geminga-1.jpg|thumb|right|250px|This is an XMM Newton image of the Gemini gamma-ray source. Credit: P.A. Caraveo (INAF/IASF), Milan and ESA.]] From 0.1 nm to 0.01 nm (about 12 to 120 keV) [are] hard X-rays. The gamma-ray source Geminga, shown at right in hard X-rays by the satellite XMM Newton, is first observed by the [[w:Second Small Astronomy Satellite|Second Small Astronomy Satellite]] (SAS-2). Geminga may be a sort of neutron star: the decaying core of a massive star that exploded as a [[w:supernova|supernova]] about 300,000 years ago.<ref name=Darling>[http://www.daviddarling.info/encyclopedia/G/Geminga.html Geminga], Internet Encyclopedia of Science</ref> This nearby explosion may be responsible for the low density of the [[interstellar medium]] in the immediate vicinity of the [[Solar System]]. This low-density area is known as the Local Bubble.<ref>{{cite journal|doi=10.1038/361706a0|title=The Geminga supernova as a possible cause of the local interstellar bubble|year=1993|last1=Gehrels|first1=Neil|last2=Chen|first2=Wan|journal=Nature|volume=361|issue=6414|pages=706–707|s2cid=4338940|url=https://zenodo.org/record/1233141}}</ref> Possible evidence for this includes findings by the [[w:Arecibo Observatory|Arecibo Observatory]] that local micrometre-sized interstellar meteor particles appear to originate from its direction.<ref>{{ cite book | url=http://www.centauri-dreams.org/?p=1741 | title=The Sun's Exotic Neighborhood | publisher=Centauri Dreams | date=2008-02-28 }}</ref> "Geminga is a very weak neutron star and the pulsar next to us, which almost only emits extremely hard gamma-rays, but no radio waves. ... Some thousand years ago our Sun entered this [Local Bubble] several hundred light-years big area, which is nearly dust-free."<ref name=Kummer>{{ cite book |author=Juergen Kummer |title=Geminga |publisher=Internetservice Kummer + Oster GbR |location=Buchenberg Germany |date=June 27, 2006 |url=http://jumk.de/astronomie/special-stars/geminga.shtml |accessdate=2013-05-08 }}</ref> {{clear}} ==Soft X-rays== [[Image:Latest xrt soft x-ray.gif|thumb|right|250px|The Sun in the soft X-rays as seen by the [[w:Hinode|Hinode]] X-ray Telescope (XRT) on October 15, 2009. Credit: Joseph B. Gurman, Facility Scientist, Solar Data Analysis Center, ISAS/JAXA and NASA.{{tlx|free media}}]] From 10 to 0.1 nanometers (nm) (about 0.12 to 12 keV) they are classified as soft x-rays. On the right is a soft X-ray image in the titanium-polyimide ("Ti_poly") filter from the Hinode X-Ray Telescope (XRT) obtained at: 2009/10/15 18:03 UTC. "The primary filter for the sigmoid observations was the “thin-aluminum/polyimide” (or “Al/poly”) filter, imaging plasmas with temperature of roughly 2–5 MK in the active region."<ref name=McKenzie>{{ cite journal |author=D. E. McKenzie and R. C. Canfield |title=Hinode XRT observations of a long-lasting coronal sigmoid |journal=Astronomy & Astrophysics |month= |year=2008 |volume=481 |issue= |pages=L65–L68 |url=http://www.aanda.org/articles/aa/pdf/2008/13/aa9035-07.pdf |arxiv= |bibcode= |doi=10.1051/0004-6361:20079035 |pmid= |accessdate=2016-11-03 }}</ref> {{clear}} ==Super soft X-rays== [[Image:Intermediate polar EX Hya.gif|right|thumb|250px|ASCA SIS spectrum of the intermediate polar EX Hya shows the H- and He-like K-alpha lines of Mg, Si, S, Ar, and Fe. Credit: Nicholas E. White.]] [[Image:Pluto Main-Chandra.jpg|right|thumb|250px|The first detection of Pluto in X-rays has been made using NASA's Chandra X-ray Observatory in conjunction with observations from NASA's New Horizons spacecraft. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Center/Chandra X-Ray Center.]] Super soft X-ray source "SSXSs are in most cases only detected below 0.5 keV".<ref name=Marshallsumter4>{{ cite book |author=[[User:Marshallsumter|Marshallsumter]] |title=Super soft X-ray source |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=March 8, 2013 |url=http://en.wikipedia.org/wiki/Super_soft_X-ray_source |accessdate=2013-05-18 }}</ref> There are three SSXSs with bolometric luminosity of ~10³⁸ erg/s that are novae: GQ Mus (BB, MW), V1974 Cyg (WD, MW), and Nova LMC 1995 (WD).<ref name=Greiner>{{ cite journal |doi=10.1016/S1384-1076(00)00018-X |author=Greiner J |title=Catalog of supersoft X-ray sources |journal=New Astron. |year=2000 |volume=5 |issue=3 |pages=137–41 |url=http://www.mpe.mpg.de/~jcg/sss/ssscat.html |arxiv = astro-ph/0005238 |bibcode = 2000NewA....5..137G }}</ref> "Apparently, as of 1999 the orbital period of Nova LMC 1995 if a binary was not known."<ref name=Marshallsumter4/> U Sco, a recurrent nova as of 1999 unobserved by ROSAT, is a WD (74-76 eV), L_bol ~ (8-60) x 10³⁶ erg/s, with an orbital period of 1.2306 d.<ref name=Greiner/> "[S]uper-soft X-rays [are] between 0.12 and 2.0 keV."<ref name=Hunt>{{ cite book |author=Nicholas Hunt-Walker |title=What Emits Astrophysical X-rays? |publisher=Univ. of Wisconsin - Madison |location=Madison, WI |date=June 2009 |url=http://www.astro.wisc.edu/~nicholas/background1.html |accessdate=2016-11-03 }}</ref> The image on the right contains counts from super soft X-rays. "The first detection of Pluto in X-rays has been made using NASA's Chandra X-ray Observatory in conjunction with observations from NASA's New Horizons spacecraft."<ref name=Lavoie2015>{{ cite book |author=Sue Lavoie |title=PIA21061: X-Rays from Pluto |publisher=NASA/JPL |location=Pasadena, California USA |date=June 2015 |url=http://photojournal.jpl.nasa.gov/catalog/PIA21061 |accessdate=2016-11-22 }}</ref> "There is a significant difference in scale between the optical and X-ray images. New Horizons made a close flyby of Pluto but Chandra is located near the Earth, so the level of detail visible in the two images is very different. The Chandra image is 180,000 miles across at the distance of Pluto, but the planet is only 1,500 miles across. Pluto is detected in the X-ray image as a point source, showing the sharpest level of detail available for Chandra or any other X-ray observatory."<ref name=Lavoie2015/> "Detecting X-rays from Pluto is a somewhat surprising result given that Pluto - a cold, rocky world without a magnetic field - has no natural mechanism for emitting X-rays. However, scientists knew from previous observations of comets that the interaction between the gases surrounding such planetary bodies and the solar wind - the constant streams of charged particles from the sun that speed throughout the solar system -- can create X-rays."<ref name=Lavoie2015/> "The immediate mystery is that Chandra's readings on the brightness of the X-rays are much higher than expected from the solar wind interacting with Pluto's atmosphere. The Chandra detection is also surprising since New Horizons discovered Pluto's atmosphere was much more stable than the rapidly escaping, "comet-like" atmosphere that many scientists expected before the spacecraft flew past in July 2015. In fact, New Horizons found that Pluto's interaction with the solar wind is much more like the interaction of the solar wind with Mars, than with a comet. While Pluto is releasing enough gas from its atmosphere to make the observed X-rays, there isn't enough solar wind flowing directly at Pluto at its great distance from the Sun to make them according to certain theoretical models."<ref name=Lavoie2015/> {{clear}} ==Ultra soft X-rays== Ultra-soft X-rays are also known as grenz-rays (GRs).<ref name=Hedblad>{{ cite journal |author=Mari-Anne Hedblad and Lotus Mallbris |title=Grenz ray treatment of lentigo maligna and early lentigo maligna melanoma |journal=Journal of the American Academy of Dermatology |month=July |year=2012 |volume=67 |issue=1 |pages=60-8 |url=http://www.jaad.org/article/S0190-9622%2811%2900837-1/abstract |arxiv= |bibcode= |doi=10.1016/j.jaad.2011.06.029 |pmid= |accessdate=2016-09-22 }}</ref> "Ultra soft X-ray spectra [are] in the range 60-250 eV".<ref name=Bleeker>{{ cite journal |author=J. A. M. Bleeker, J. Davelaar, A. J. M. Deerenberg, H. Huizenga, A. C. Brinkman, J. Heise, Y. Tanaka, S. Hayakawa and K. Yamashita |title=Observation of the Ultra Soft X-ray Spectrum of HZ 43 |journal=Astronomy and Astrophysics |month=September |year=1978 |volume=69 |issue=1 |pages=145-148 |url=http://adsabs.harvard.edu/full/1978A%26A....69..145B |arxiv= |bibcode=1978A&A....69..145B |doi= |pmid= |accessdate=2016-11-03 }}</ref> "''Ultrasoft X-rays'': When wavelength is greater than (10) A."<ref name=Jalil>{{ cite journal |author=Marwa I. Jalil, Salman Z. Khalaf, and Qusay A. Abbas |title=X-ray Emission Spectroscopy for the plasmas of 153P/Ikeya-Zhang and 46P/Wirtanen Comets |journal=Global Scientific Journals |date=January 2021 |volume=9 |issue=1 |pages=1952-1959 |url=https://www.researchgate.net/profile/Qusay-Abbas-3/publication/349158345_X-ray_Emission_Spectroscopy_for_the_plasmas_of_153PIkeya-Zhang_and_46PWirtanen_Comets/links/60230fdea6fdcc37a815db1f/X-ray-Emission-Spectroscopy-for-the-plasmas-of-153P-Ikeya-Zhang-and-46P-Wirtanen-Comets.pdf |arxiv= |bibcode= |doi= |pmid= |accessdate=13 January 2022 }}</ref> An Ångström is equal to 0.1 nm. "The emitted X-ray radiation with wavelength between about 0.01 to 10 nm are important for studies of solar system nature and astrophysical applications because the composition of comets can be definitely specified which gives a fair picture about the solar system development in its early stages."<ref name=Jalil/> Soft "or less penetrating x-rays, [...] have wavelengths from 3 to 20 Å, and "ultrasoft" x-rays with wavelengths in the 20 to 100 Å range."<ref name=Underwood>{{ cite journal |author=James H. Underwood |title=X-Ray Optics |journal=American Scientist |date=July-August 1978 |volume=66 |issue=4 |pages=476-486 |url=https://www.jstor.org/stable/27848756 |arxiv= |bibcode= |doi= |pmid= |accessdate=13 January 2022 }}</ref> ==Ultraviolets== {{main|Radiation astronomy/Ultraviolets|Ultraviolet astronomy}} '''Def.''' "the spectral region bounded on the long wavelength side at about λ3000 by the onset of atmospheric ozone absorption and on the short wavelength side at λ912 by the photoionization of interstellar hydrogen" is called the '''ultraviolet'''.<ref name=Bless>{{ cite journal |author=R. C. Bless and A. D. Code |title=Ultraviolet Astronomy |journal=Annual Review of Astronomy and Astrophysics |month= |year=1972 |volume=10 |issue= |pages=197-226 |url= |arxiv= |bibcode=1972ARA&A..10..197B |doi=10.1146/annurev.aa.10.090172.001213 |pmid= |accessdate=2012-01-18 }}</ref> The draft ISO standard on determining solar irradiances (ISO-DIS-21348)⁵ describes the following ranges: {| class="wikitable" |- !Name !Abbreviation ![[Wavelength]] range in [[w:nanometers|nanometers]] !Energy per photon |- |''Before UV spectrum'' |''[[w:Visible light|Visible light]]'' |''above 400&nbsp;nm'' |''below 3.10 eV'' |- |Ultraviolet A, long wave, or [[w:black light|black light]] |UVA |400&nbsp;nm&ndash;315&nbsp;nm |3.10&ndash;3.94 eV |- |'''Near''' |NUV |400&nbsp;nm&ndash;300&nbsp;nm |3.10&ndash;4.13 eV |- |Ultraviolet B or medium wave |UVB |315&nbsp;nm&ndash;280&nbsp;nm |3.94&ndash;4.43 eV |- |'''Middle''' |MUV |300&nbsp;nm&ndash;200&nbsp;nm |4.13&ndash;6.20 eV |- |Ultraviolet C, short wave, or [[w:Ultraviolet germicidal irradiation|germicidal]] |UVC |280&nbsp;nm&ndash;100&nbsp;nm |4.43&ndash;12.4 eV |- |'''Far''' |FUV |200&nbsp;nm&ndash;122&nbsp;nm |6.20&ndash;10.2 eV |- |'''Vacuum''' |VUV |200&nbsp;nm&ndash;100&nbsp;nm |6.20&ndash;12.4 eV |- |'''Low''' |LUV |100&nbsp;nm&ndash;88&nbsp;nm |12.4&ndash;14.1 eV |- |'''Super''' |SUV |150&nbsp;nm&ndash;10&nbsp;nm |8.28&ndash;124 eV |- |'''Extreme''' |[[w:Extreme ultraviolet|EUV]] |121&nbsp;nm&ndash;10&nbsp;nm |10.2&ndash;124 eV |- |''Beyond UV range'' |''[[w:X-ray|X-ray]]s'' |''below 10&nbsp;nm'' |''above 124 eV'' |} "Vacuum UV" is so named because it is absorbed strongly by [[w:air|air]] and is, therefore, used in a [[w:vacuum|vacuum]]. In the long-wave limit of this region, roughly 150&ndash;200&nbsp;nm, the principal absorber is the [[w:oxygen|oxygen]] in air. ==Extreme ultraviolets== [[Image:Ultiwavelength extreme ultraviolet sun.jpg|right|thumb|250px|A full-disk multiwavelength extreme ultraviolet image of the sun taken by SDO on March 30, 2010. Credit: NASA/Goddard/SDO AIA Team.{{tlx|free media}}]] "A full-disk multiwavelength extreme ultraviolet image of the sun [was] taken by SDO on March 30, 2010. False colors trace different gas temperatures. Reds are relatively cool (about 60,000 Kelvin, or 107,540 F); blues and greens are hotter (greater than 1 million Kelvin, or 1,799,540 F)."<ref name=Zell>{{ cite web |author=Holly Zell |title=First-light |publisher=NASA |location=Washington, DC USA |date=30 March 2010 |url=http://www.nasa.gov/mission_pages/sdo/news/first-light.html |accessdate=2016-11-03 }}</ref> "Some of the images from the spacecraft show never-before-seen detail of material streaming outward and away from sunspots. Others show extreme close-ups of activity on the sun’s surface. The spacecraft also has made the first high-resolution measurements of solar flares in a broad range of extreme ultraviolet wavelengths."<ref name=Zell/> "The Extreme Ultraviolet Variability Experiment measures fluctuations in the sun’s radiant emissions. These emissions have a direct and powerful effect on Earth’s upper atmosphere -- heating it, puffing it up, and breaking apart atoms and molecules."<ref name=Zell/> {{clear}} ==Far ultraviolets== [[Image:Earth in ultraviolet from the Moon (S72-40821).jpg|thumb|right|250px|This image shows how the Earth glows in the ultraviolet. Credit: John W. Young, Apollo 16 lunar landing mission, NASA.]] "This unusual false-color image [at right] shows how the Earth glows in ultraviolet (UV) light. The Far UV Camera/Spectrograph deployed and left on the Moon by the crew of Apollo 16 captured this image. The part of the Earth facing the Sun reflects much UV light and bands of UV emission are also apparent on the side facing away from the Sun. These bands are the result of aurora caused by charged particles given off by the Sun. They spiral towards the Earth along Earth's magnetic field lines."<ref name=Netting>{{ cite book |author=Ruth Netting |title=ULTRAVIOLET LIGHT FROM OUR SUN |publisher=NASA |location=Washington, DC USA |date=March 22, 2011 |url=http://missionscience.nasa.gov/ems/10_ultravioletwaves.html |accessdate=2013-05-29 }}</ref> "An artificially reproduced color enhancement [at right] of a ten-minute far-ultraviolet exposure of Earth, taken with a filter which blocks the glow caused by atomic hydrogen but which transmits the glow caused by atomic oxygen and molecular nitrogen. Note that airglow emission bands are visible on the night side of Earth, one roughly centered between the two polar auroral zones and one at an angle to this extending northward toward the sunlit side of Earth. The UV camera was operated by astronaut John W. Young on the Apollo 16 lunar landing mission."<ref name=Kauderer>{{ cite book |author=Amiko Kauderer |title=Apollo Imagery |publisher=NASA |location=Washington, DC USA |date=21 April 1972 |url=http://spaceflight.nasa.gov/gallery/images/apollo/apollo16/html/s72-40821.html |accessdate=2016-11-03 }}</ref> {{clear}} ==Middle ultraviolets== "Spectra of Venus (~35 Å resolution) and Jupiter (~50 Å resolution) were obtain using objective grating spectrographs in the 2300-3700 Å wavelength range. The geometric reflectivity of Jupiter, as a function of wavelength, lies in the range 0.15 to 0.25; that of Venus, 0.08 to 0.40."<ref name= Evans>{{ cite journal |author=D. C. Evans, A. Boggess, III, and R. Scolnik |title=The Reflectivity of Venus and Jupiter in the Middle Ultraviolet |journal=Astronomical Journal |month= |year=1965 |volume=70 |issue= |pages=321 |url=http://adsabs.harvard.edu/full/1965AJ.....70..321E |arxiv= |bibcode=1965AJ.....70..321E |doi= |pmid= |accessdate=2016-11-04 }}</ref> ==Near ultraviolets== [[Image:Z Camelopardalis GALEX.jpg|right|thumb|250px|This composite image shows Z Camelopardalis, or Z Cam, a double-star system featuring a collapsed, dead star, called a white dwarf, and a companion star, as well as a ghostly shell around the system. Credit: NASA/JPL-Caltech/M. Seibert(OCIW)/T. Pyle(SSC)/R. Hurt(SSC).]] "This composite image [on the right] shows Z Camelopardalis, or Z Cam, a double-star system featuring a collapsed, dead star, called a white dwarf, and a companion star, as well as a ghostly shell around the system. The massive shell provides evidence of lingering material ejected during and swept up by a powerful classical nova explosion that occurred probably a few thousand years ago."<ref name=Seibert/> "The image combines data gathered from the far-ultraviolet and near-ultraviolet detectors on NASA's Galaxy Evolution Explorer on Jan. 25, 2004. The orbiting observatory first began imaging Z Cam in 2003."<ref name=Seibert/> "Z Cam is the largest white object in the image, located near the center. Parts of the shell are seen as a lobe-like, wispy, yellowish feature below and to the right of Z Cam, and as two large, whitish, perpendicular lines on the left."<ref name=Seibert/> "Z Cam was one of the first known recurrent dwarf nova, meaning it erupts in a series of small, "hiccup-like" blasts, unlike classical novae, which undergo a massive explosion."<ref name=Seibert/> The "huge shell around Z Cam [...] it could only be explained as the remnant of a full-blown classical nova explosion. This finding provides the first evidence that some binary systems undergo both types of explosions. Previously, a link between the two types of novae had been predicted, but there was no evidence to support the theory."<ref name=Seibert/> "The faint bluish streak in the bottom right corner of the image is ultraviolet light reflected by dust that may or may not be related to Z Cam."<ref name=Seibert/> "The yellow objects are strong near-ultraviolet emitters; blue features have strong far-ultraviolet emission; and white objects have nearly equal amounts of near-ultraviolet and far-ultraviolet emission."<ref name=Seibert>{{ cite book |author=M. Seibert, T. Pyle and R. Hurt |title=Scene of Multiple Explosions |publisher=NASA/Jet Propulsion Laboratory. |location=Pasadena, California USA |date=7 March 2007 |url=http://www.galex.caltech.edu/media/glx2007-01r_img02.html |accessdate=4 November 2016 }}</ref> {{clear}} ==Opticals== {{main|Radiation astronomy/Opticals|Optical astronomy}} [[Image:U Camelopardalis.jpeg|thumb|left|250px|This is an optical image of U Camelopardalis from the Hubble Space Telescope. Credit: ESA/Hubble, NASA and H. Olofsson (Onsala Space Observatory).]] '''Optics''' is the branch of [[physics]] which involves the behavior and properties of light, including its interactions with matter and the construction of instruments that use or detect it.<ref name=McGrawHill>{{ cite book |title=McGraw-Hill Encyclopedia of Science and Technology |edition=5th |publisher=McGraw-Hill |date=1993 }}</ref> Optics usually describes the behavior of visible, ultraviolet, and infrared light. Geometric optics treats light as a collection of rays that travel in straight lines and bend when they pass through or reflect from surfaces. Physical optics is a more comprehensive model of light, which includes wave effects such as diffraction and interference that cannot be accounted for in geometric optics. Although visible light itself extends from approximately 4000 Å to 7000 Å (400 nm to 700&nbsp;nm),<ref name="moore1997">{{cite book |author=Moore, P. |title=Philip's Atlas of the Universe |date=1997 |publisher=George Philis Limited |location=Great Britain |isbn=0-540-07465-9}}</ref> the same equipment used at these wavelengths is also used to observe some near-ultraviolet and near-infrared radiation. "A bright star [in the image at left] is surrounded by a tenuous shell of gas in this unusual image from the NASA/ESA Hubble Space Telescope. U Camelopardalis, or U Cam for short, is a star nearing the end of its life. As it begins to run low on fuel, it is becoming unstable. Every few thousand years, it coughs out a nearly spherical shell of gas as a layer of helium around its core begins to fuse. The gas ejected in the star’s latest eruption is clearly visible in this picture as a faint bubble of gas surrounding the star."<ref name=Olofsson>{{ cite book |author=H. Olofsson |title=Red giant blows a bubble |publisher=SpaceTelescope Organization |location=Maryland USA |date=July 2, 2012 |url=http://www.spacetelescope.org/images/potw1227a/ |accessdate=2013-12-24 }}</ref> "U Cam is an example of a carbon star. This is a rare type of star whose atmosphere contains more carbon than oxygen. Due to its low surface gravity, typically as much as half of the total mass of a carbon star may be lost by way of powerful stellar winds."<ref name=Olofsson/> "Located in the constellation of Camelopardalis (The Giraffe), near the North Celestial Pole, U Cam itself is actually much smaller than it appears in Hubble’s picture. In fact, the star would easily fit within a single pixel at the centre of the image. Its brightness, however, is enough to overwhelm the capability of Hubble’s Advanced Camera for Surveys making the star look much bigger than it really is. The shell of gas, which is both much larger and much fainter than its parent star, is visible in intricate detail in Hubble’s portrait. While phenomena that occur at the ends of stars’ lives are often quite irregular and unstable (see for example Hubble’s images of Eta Carinae, potw1208a), the shell of gas expelled from U Cam is almost perfectly spherical."<ref name=Olofsson/> "The image was produced with the High Resolution Channel of the Advanced Camera for Surveys [using the 606 nm and 814 nm filters]."<ref name=Olofsson/> {{clear}} ==Polars== {{main|Radiation astronomy/Polarizations}} [[Image:VY Canis Majoris.jpg|right|thumb|250px|Massive outbursts from the hypergiant star VY Canis Majoris are mapped with polarized light. Credit: NASA, ESA, and R. Humphreys (University of Minnesota).]] Light given off by a star is un-polarized, i.e. the direction of oscillation of the light wave is random. However, when the light is reflected off the atmosphere of a planet, the light waves interact with the molecules in the atmosphere and they are polarized.<ref name=Schmid>{{ cite journal | author=Schmid, H. M.; Beuzit, J.-L.; Feldt, M. et al. | title=Search and investigation of extra-solar planets with polarimetry | journal=Direct Imaging of Exoplanets: Science & Techniques. Proceedings of the IAU Colloquium #200 | year=2006 | volume= 1 | issue= C200 | pages=165–170 | bibcode=2006dies.conf..165S | doi=10.1017/S1743921306009252 }}</ref> "The outbursts [shown in polarized light in the image on the right] are from VY Canis Majoris, a red supergiant star that is also classified as a hypergiant because of its very high luminosity. The eruptions have formed loops, arcs, and knots of material moving at various speeds and in many different directions. The star has had many outbursts over the past 1,000 years as it nears the end of its life."<ref name=Weaver>{{ cite book |author=Donna Weaver and Roberta Humphreys |title=Astronomers Map a Hypergiant Star's Massive Outbursts |publisher=Hubblesite |location=Baltimore, Maryland USA |date=March 2007 |url=http://hubblesite.org/newscenter/archive/releases/2007/03/full/ |accessdate=2016-11-05 }}</ref> "The polarized light shows how the dust is distributed."<ref name=Weaver/> "VY Canis Majoris is ejecting large amounts of gas at a prodigious rate".<ref name=Humphreys>{{ cite book |author=Roberta Humphreys |title=Astronomers Map a Hypergiant Star's Massive Outbursts |publisher=Hubblesite |location=Baltimore, Maryland USA |date=March 2007 |url=http://hubblesite.org/newscenter/archive/releases/2007/03/full/ |accessdate=2016-11-05 }}</ref> "With these observations, we have a complete picture of the motions and directions of the outflows, and their spatial distribution, which confirms their origin from eruptions at different times from separate regions on the star."<ref name=Humphreys/> "The outermost material was ejected about 1,000 years ago, while a knot near the star may have been ejected as recently as 50 years ago."<ref name=Weaver/> {{clear}} ==Visuals== {{main|Radiation astronomy/Visuals|Visual astronomy}} [[Image:NorthernLights2.jpg|thumb|right|250px|This yellow aurora near the horizon has many vertical rays, sometimes called "light pillars", though these are probably not from ice crystals. Credit: Unknown, or unstated.]] [[Image:Northern Lights Queenstown New Zealand July 2012.jpg|thumb|right|250px|These two rays in the foreground are distinctive from the background aurora. Credit: Unknown, or unstated.]] [[Image:Aurorarays anderson.jpg|thumb|left|250px|The image shows rays from an unexpected aurora. Credit: Anderson.]] {| class="wikitable" style="float:right; width:400px; text-align:center; margin:0.5em auto; width:auto; margin-left:1em;" |- ! colspan="3" style="background:#FFF;" | [[Image:Linear visible spectrum.svg|center|250px|sRGB rendering of the spectrum of visible light]] |- !Color |[[Frequency]] |[[Wavelength]] |- | style="background:#ccb0f4;"|'''violet''' |668–789&nbsp;THz |380–450&nbsp;nm |- | style="background:#b0b0f4;"|'''blue''' |631–668&nbsp;THz |450–475&nbsp;nm |- | style="background:#b0f4f4;"|'''cyan''' |606–630&nbsp;THz |476–495&nbsp;nm |- | style="background:#b0f4b0;"|'''green''' |526–606&nbsp;THz |495–570&nbsp;nm |- | style="background:#f4f4b0;"|'''yellow''' |508–526&nbsp;THz |570–590&nbsp;nm |- | style="background:#f4ccb0;"|'''orange''' |484–508&nbsp;THz |590–620&nbsp;nm |- | style="background:#f4b0b0;"|'''red''' |400–484&nbsp;THz |620–750&nbsp;nm |} The '''visible spectrum''' is the portion of the electromagnetic spectrum that is visible to (can be detected by) the human eye. Electromagnetic radiation in this range of [[wavelength]]s is called '''visible light''' or simply light. A typical human eye will respond to wavelengths from about 390 to 750&nbsp;nm.<ref name=Starr>{{ cite book | title = Biology: Concepts and Applications | author = Cecie Starr | publisher = Thomson Brooks/Cole | date = 2005 | isbn = 053446226X | url = http://books.google.com/?id=RtSpGV_Pl_0C&pg=PA94 }}</ref> In terms of frequency, this corresponds to a band in the vicinity of 400–790 THz. A light-adapted eye generally has its maximum sensitivity at around 555&nbsp;[[w:nanometre|nm]] (540 THz), in the green region of the optical spectrum (see: luminosity function). There are several cases of astronomers who claimed that following a cataract operation, they could see shorter wavelengths than other people, slightly into the ultraviolet. The image on the right shows a yellow aurora near the horizon that has many vertical rays, sometimes called "light pillars", though these are probably not from ice crystals. The second image down on the right shows two distinctive rays in the foreground that terminate in yellow over Queenstown, New Zealand, in July 2012. "This aurora [on the left] was a bit of a surprise. For starters, on this Friday morning in August 2002, no intense auroral activity was expected at all. Possibly more surprising, however, the aurora appeared to show an usual structure of green rays from some locations. In the [left] image, captured from North Dakota, USA, a picket fence of green rays stretches toward the horizon. Mirroring the green rays is a red band, somewhat rare in its own right. Lights from the cities of Bismarck and Mandan are visible near the horizon. Large sunspot groups indicate that activity from an active Sun is relatively likely, possibly causing other streams of energetic particles to cascade onto the Earth and so causing more auroras."<ref name=Nemiroff2005>{{ cite book |author=Robert Nemiroff & Jerry Bonnell |title=Rays from an Unexpected Aurora |publisher=NASA |location=Washington, DC USA |date=19 November 2005 |url=http://www.astronet.ru/db/xware/msg/1209585 |accessdate=2015-11-30 }}</ref> "The ray structure often seen in arcs and bands marks out the orientation of the magnetic field, nearly vertical at high latitude. The vertical extent of arcs and bands is also along this direction. Though the rays appear to converge upward, they are, in reality, essentially parallel shafts of light."<ref name=Davis>{{ cite book |author=T. Neil Davis |title=Auroral Arcs and Bands |publisher=Geophysical Institute, University of Alaska Fairbanks |location=Fairbanks, Alaska USA |date=18 December 1979 |url=http://www2.gi.alaska.edu/ScienceForum/ASF3/362.html |accessdate=2015-12-01 }}</ref> "If rayed aurora is directly overhead, the point to which the rays appear to converge is the magnetic zenith. A line from that point to the observer marks out the local direction of the earth's magnetic field."<ref name=Davis/> "Standing in the aurora like pickets in a fence, the rays sometimes move sideways across the arcs and bands at high speeds. Sometimes one even sees them appear to move past each other both to the left and the right."<ref name=Davis1981>{{ cite book |author=T. Neil Davis |title=Auroral Rays |publisher=Geophysical Institute, University of Alaska Fairbanks |location=Fairbanks, Alaska USA |date=30 March 1981 |url=http://www2.gi.alaska.edu/ScienceForum/ASF3/362.html |accessdate=2015-12-01 }}</ref> "Rays line up along the direction of the earth's magnetic field, which points nearly vertically and somewhat to the northeast over Alaska and western Canada. To recognize the cross-sectional shapes of the rays, one needs to see them directly overhead in the sky. When they are in that position, they don't look like rays anymore; one reason why it took so long to discover their true shapes."<ref name=Davis1981/> "Not until very sensitive, high-speed television cameras were aimed at the bottoms of rays overhead was the mystery resolved. [The] rays were tightly wound up spirals only a kilometer or two across. Their form is difficult to recognize with the naked eye because the curled up shapes develop so quickly--sometimes in a second or so--and they often move very rapidly."<ref name=Davis1981/> "With a television camera capable of taking 30 pictures each second, it was possible to record the development of the spiral-shaped rays and measure their motion. Sometimes they move across the sky at speeds one hundred times that of a jet aircraft. To the observer on the ground, they do not appear to move quite that fast because the rays are so far away."<ref name=Davis1981/> {{clear}} ==Colors== {{main|Radiation astronomy/Colors}} [[Image:White and green separate curtains.jpg|thumb|right|250px|The image shows separate curtains of an aurora borealis. Credit: surangaw / Fotolia.]] Usually auroras seen locally are arcs that are part of an auroral oval around or near the magnetic poles. In the image on the right are separate curtains apparently from one aurora borealis. {{clear}} ==Ices== {{main|Minerals/Ices}} [[Image:Lightpillars kast 960.jpg|thumb|right|250px|The image shows light pillars over Finland. Credit: Thomas Kast.]] "Pictured [on the right] are not aurora but nearby light pillars, a local phenomenon that can appear as a distant one. In most places on Earth, a lucky viewer can see a Sun-pillar, a column of light appearing to extend up from the Sun caused by flat fluttering ice-crystals reflecting sunlight from the upper atmosphere. Usually these ice crystals evaporate before reaching the ground. During freezing temperatures, however, flat fluttering ice crystals may form near the ground in a form of light snow, sometimes known as a crystal fog. These ice crystals may then reflect ground lights in columns not unlike a Sun-pillar."<ref name=Nemiroff2013>{{ cite book |author=Robert Nemiroff & Jerry Bonnell |title=Light Pillars over Finland |publisher=NASA |location=Washington, DC USA |date=18 December 2013 |url=http://apod.nasa.gov/apod/ap131218.html |accessdate=2015-11-23 }}</ref> These "light pillars [are] extending up from bright parking lot lights in Oulu, Finland."<ref name=Nemiroff2013/> '''Def.''' a "visual phenomenon created by the reflection of light from ice crystals with near-horizontal parallel planar surfaces"<ref name=LightPillarWikt>{{ cite book |author=[[wikt:User:Equinox|Equinox]] |title=light pillar |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=23 April 2014 |url=https://en.wiktionary.org/wiki/light_pillar |accessdate=2015-11-23 }}</ref> is called a '''light pillar'''. {{clear}} ==Fluorescences== {{main|Radiation astronomy/Fluorescences}} '''Fluorescence''' is the emission of light by a substance that has absorbed light or other [[w:electromagnetic radiation|electromagnetic radiation]]. It is a form of [[w:luminescence|luminescence]]. In most cases, the emitted light has a longer wavelength, and therefore lower energy, than the absorbed radiation. However, when the absorbed electromagnetic radiation is intense, it is possible for one electron to absorb two [[w:photon|photon]]s; this [[w:two-photon absorption|two-photon absorption]] can lead to emission of radiation having a shorter wavelength than the absorbed radiation. The emitted radiation may also be of the same wavelength as the absorbed radiation, termed "resonance fluorescence".<ref name=Holler>''Principles Of Instrumental Analysis'' F.James Holler, Douglas A. Skoog & Stanley R. Crouch 2006</ref> The most striking examples of fluorescence occur when the absorbed radiation is in the [[w:ultraviolet|ultraviolet]] region of the spectrum, and thus invisible to the human eye, and the emitted light is in the visible region. The common [[w:fluorescent lamp|fluorescent lamp]] relies on fluorescence. Inside the glass tube is a partial vacuum and a small amount of [[w:mercury (element)|mercury]]. An electric discharge in the tube causes the mercury atoms to emit ultraviolet light. The tube is lined with a coating of a fluorescent material, called the ''[[w:phosphor|phosphor]]'', which absorbs the ultraviolet and re-emits visible light. Fluorescent [[w:lighting|lighting]] is more energy-efficient than incandescent lighting elements. However, the uneven [[w:spectrum|spectrum]] of traditional fluorescent lamps may cause certain colors to appear different than when illuminated by incandescent light or [[w:daylight|daylight]]. The mercury vapor emission spectrum is dominated by a short-wave UV line at 254&nbsp;nm (which provides most of the energy to the phosphors), accompanied by visible light emission at 436&nbsp;nm (blue), 546&nbsp;nm (green) and 579&nbsp;nm (yellow-orange). These three lines can be observed superimposed on the white continuum using a hand spectroscope, for light emitted by the usual white fluorescent tubes. These same visible lines, accompanied by the emission lines of trivalent europium and trivalent terbium, and further accompanied by the emission continuum of divalent europium in the blue region, comprise the more discontinuous light emission of the modern trichromatic phosphor systems used in many [[w:compact fluorescent lamp|compact fluorescent lamp]] and traditional lamps where better color rendition is a goal.<ref name="How Fluorescent Lamps Work">{{ cite book |author=Tom Harris |title=How Fluorescent Lamps Work |url=http://home.howstuffworks.com/fluorescent-lamp.htm |publisher=Discovery Communications |accessdate=27 June 2010}}</ref> ==Luminescences== {{main|Radiation astronomy/Luminescences}} [[Image:Luminol.jpg|thumb|right|250px|Luminol glows in an alkalic solution when you add Hemoglobin and H₂O₂. Credit: [http://www.flickr.com/people/84263780@N00 everyone's idle from berlin, germany].]] '''Def.''' any "emission of light that cannot be attributed merely to the temperature of the emitting body"<ref name=LuminescenceWikt>{{ cite book |author=[[wikt:User:SemperBlotto|SemperBlotto]] |title=luminescence |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=3 April 2006 |url=https://en.wiktionary.org/wiki/luminescence |accessdate=2016-09-22 }}</ref> is called '''luminescence'''. {{clear}} ==Whites== [[Image:LhotseMountain.jos.500pix.jpg|thumb|right|250px|Lhotse is seen from the climb up to Chhukung Ri. Credit: Jamie O'Shaughnessy.]] [[Image:White Aurora from thefancy.jpg|thumb|right|250px|This is a white aurora. Credit: hensen.]] [[Image:White aurora over Canada.png|thumb|left|250px|This is a predominantly white aurora over Canada. Credit: Paul Zizka.]] '''White''' is the color of fresh milk and snow.<ref name="Shorter Oxford English Dictionary 2002">''Shorter Oxford English Dictionary'', 5th Edition (2002)</ref><ref>See ''Shorter Oxford English Dictionary'', 5th Edition (2002); "of the colour of fresh milk or snow." See also ''Webster's New World Dictionary of American English'', Third College Edition, (1988): "Having the color of pure snow or milk." See also ''The Random House College Dictionary of the English Language'', Revised Edition,(1980)</ref> It is the color the human eye sees when it looks at light which contains all the wavelengths of the visible spectrum, at full brightness and without absorption. It does not have any hue.<ref>''Shorter Oxford English Dictionary'', 5th Edition (2002)</ref> {{lang|fr|"de la couleur de la neige, du lait. Lumiere resultant de la combinaison de toutes les couleurs du spectre solaire."}}<ref name=Larousse>{{ cite book |author=Petit Larousse |title=Petit Larousse illustré: nouveau dictionnaire encyclopédique |publisher= |location= |date=2005 |editor= |pages= |url=https://books.google.com/books?id=dRMiAQAAIAAJ&printsec=frontcover&hl=en&sa=X&ved=0ahUKEwi4kJTJ8dLjAhWeHzQIHRRuBG8Q6AEIKjAA#v=onepage&f=false |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2013-05-02 }}</ref> (of the color of snow, of milk. Light resulting from the combination of all the colors of the solar spectrum.) The images on the right and left show white auroras. {{clear}} ==Multicolored auroras== {{main|Plasmas/Plasma objects/Auroras}} [[Image:Multicolor aurora.jpg|thumb|right|250px|This is a multicolor aurora. Credit: tommy-eliassen and leonafaye.]] [[Image:Colorful-aurora-borealis-in-finland.jpg|thumb|left|250px|This shows a multicolored aurora over Finland. Credit: S. D. Simonson.]] "Auroras are known to be generated by beams of electrons which are accelerated along Earth's magnetic field lines. The fast-moving electrons collide with atoms in the ionosphere at altitudes of between 100 to 600 km. This interaction with oxygen atoms results in a green or, more rarely, red glow in the night sky, while nitrogen atoms yield blue and purple colours."<ref name=Wright/> On the right and left are two images of multicolored auroras. The second down on the right occurred over Finland in October 2012. {{clear}} ==Blacks== [[Image:Coal anthracite.jpg|thumb|right|250px|Anthracite coal is black. Credit: USGS and the Mineral Information Institute.]] [[Image:Basalt in albitite.jpg|thumb|left|250px|Basalt is a black rock, albite is a white mineral silicate, and epidote is green. Credit: [[commons:User:Siim|Siim Sepp]].]] [[Image:Colors Of Our Vibrations Iceland Oct 2013.jpg|thumb|right|250px|This image appears to contain a black aurora between the red and green. Credit: Unknown, or not stated.]] [[Image:Northern Lights Tromso Nov Norway Oct 2012.jpg|thumb|right|250px|This aurora over Tromso, Norway, appears to contains a black aurora. Credit: Unknown, or unstated.]] [[Image:Northern Lights Alaska 2012.jpg|thumb|right|250px|This is apparently the first of two images of auroras over Fairbanks, Alaska. Credit: Unknown, or unstated.]] [[Image:Northern Lights Fairbanks Alaska 2012.jpg|thumb|right|250px|This is apparently the second of two images of auroras over Fairbanks, Alaska. Credit: Unknown, or unstated.]] '''Black''' is the color of [[w:coal|coal]], [[w:ebony|ebony]], and of [[w:outer space|outer space]]. It is the darkest color, the result of the absence of or complete absorption of light. It is the opposite of white and often represents darkness in contrast with light.<ref name=Shorter>''Shorter Oxford English Dictionary''. 5th Edition (2002)</ref><ref name=Webster>See also ''Webster's New World Dictionary of the American Language'' (1964)</ref><ref name=Petit>''Le Petit Larousse Illustré'' (1997)</ref> "Opposite to white: colourless from the absence or complete absorption of light. Also, so near this as to have no distinguishable colour, very dark."<ref name=Shorter/> Black is "[t]he darkest color".<ref name=Webster/> {{lang|fr|"Se dit de la couleur la plus foncée, due à l'absence ou à l'absorption totale des rayons lumineux."}}<ref name=Petit/>("said of the very darkest color, due to the absence or complete absorption of all rays of light.") "Most people have heard of auroras - more commonly known as the Northern and Southern Lights - but, except on rare occasions, such as the recent widespread apparition on 17 March, they are not usually visible outside the polar regions. Less familiar are phenomena known as black auroras, dark patches which often subdivide the glowing curtains of red and green light."<ref name=Wright>{{ cite book |author=Andrew Wright |title=Heart of the Black Auroras Revealed by Cluster |publisher=European Space Agency |location= |date=9 April 2015 |url=http://sci.esa.int/cluster/55764-heart-of-the-black-auroras-revealed-by-cluster/ |accessdate=2015-04-12 }}</ref> "Whereas bright auroras are created by electrons plunging downward into the ionosphere, neighbouring black auroras are caused by electrons escaping from the ionosphere - like a kind of anti-aurora. However, until now, scientists have been struggling to explain the relationship between the two auroral types."<ref name=Wright/> "We found strong evidence of a two-way interaction between the ionosphere and the magnetosphere."<ref name=Russell>{{ cite book |author=Alexander Russell |title=Heart of the Black Auroras Revealed by Cluster |publisher=European Space Agency |location= |date=9 April 2015 |url=http://sci.esa.int/cluster/55764-heart-of-the-black-auroras-revealed-by-cluster/ |accessdate=2015-04-12 }}</ref> "Auroral arcs are created by electric currents. The beam of electrons shooting down towards Earth along magnetic field lines is actually an electric current aligned with Earth's magnetic field. It is called an upward, field-aligned current because the negatively charged electrons are moving downward."<ref name=Russell/> "On the other hand, when a downward magnetospheric current meets the ionosphere, electrons are driven upwards and 'sucked' from the ionosphere, creating a black aurora. However, when the electron density in the ionosphere drops markedly the black aurora becomes less intense."<ref name=Russell/> "This evacuation of the ionosphere is essential in shaping the black auroras. The process is much more important on Earth's nightside than on the dayside because sunlight creates new electrons which fill the 'hole'."<ref name=Russell/> The "two-way electrodynamic coupling between the magnetosphere and ionosphere [...] is made possible by a horizontal drift of ions in the ionosphere, known as the Pedersen current, which closes the current system."<ref name=Russell/> "According to convention, negatively charged electrons flow downward, from the magnetosphere to the ionosphere, in an upward field-aligned current. Electrons flow upward, from the ionosphere to the magnetosphere, in a downward field-aligned current."<ref name=Wright/> The third and fourth images down on the right are apparently two successive images of the same aurora showing changes with time and black auroras. {{clear}} ==Grays== [[Image:Color icon gray v2.svg|thumb|left|250px|These are the various shades of gray. Credit: Mizunoryu, Badseed, Jacobolus.]] [[Image:Red pebbles gray rocks.jpg|thumb|right|250px|This image shows some red pebbles among gray pebbles of the same rock type. Credit: Titus Tscharntke.]] [[Image:Gumbo lily flower among gray rocks oenothera caespitosa.jpg|thumb|left|250px|Gray clay shows the cracking from water loss. Credit: Barnes Dr Thomas G, U.S. Fish and Wildlife Service.]] '''Grey''' or '''gray''' is an intermediate color between black and white, a neutral or achromatic color, meaning literally a color "without color." <ref>''Webster's New World Dictionary of the American Language'', Third College Edition.</ref> It is the color of a cloud-covered sky, of [[w:wood ash|ash]] and of [[w:lead|lead]].<ref>''Shorter Oxford English Dictionary'', 5th edition, 2002.</ref> The first image at right shows some red pebbles among gray pebbles, which are all the same rock type. The first image at left shows the various shades of grey. The second image at left of gray clay shows the cracking from water loss. {{clear}} ==Violets== {{main|Radiation astronomy/Violets|Violet astronomy}} [[Image:Color icon violet v2.svg|thumb|250px|right|Various shades of violet are shown. Credit: Mizunoryu, Badseed, Jacobolus.]] [[Image:Color icon purple.svg|thumb|250px|left|Variations of violet are shown. Credit: [[commons:User:Badseed|Badseed]].]] [[Image:Color icon purple v2.svg|thumb|250px|upright|The diagram shows various shades of purple. Credit: Mizunoryu, Badseed, Jacobolus.]] [[Image:Violet aurora.jpg|thumb|left|250px|The aurora borealis imaged shows blue, violet, and purple colors. Credit: Ragnar Sigurdsson.]] [[Image:Violet aurora Ohio US Oct 2013.jpg|thumb|right|250px|This multicolored aurora has a strong violet band above the pink band. Credit: Black Swamp Storm Intercept Team.]] '''Violet''' is a bright bluish purple color that takes its name from the [[w:Viola (plant)|violet]] flower.<ref name=Webster/> ... Violet is at the lower end of [[w:spectrum of light|spectrum of light]], with a wavelength between approximately 380-450 nanometers.<ref name=Hunt1980>{{cite book | title = Measuring Color | author = J. W. G. Hunt | date = 1980 | publisher = Ellis Horwood Ltd | isbn = 0-7458-0125-0 }}</ref> '''Def.''' a [[wikt:blue|bluish]]-[[wikt:purple|purple]] [[wikt:colour|colour]] is called '''violet'''. '''Def.''' a colour/color that is a dark blend of red and blue; dark [[wikt:|magenta]] is called '''purple'''. '''Purple''' is a range of hues of color occurring between red and blue.<ref name=Mish>Mish, Frederic C., Editor in Chief ''Webster's Ninth New Collegiate Dictionary'' Springfield, Massachusetts, U.S.A.:1984--Merriam-Webster Page 957</ref> The ''Oxford English Dictionary'' describes it as a deep, rich shade between [[w:crimson|crimson]] and [[w:violet (color)|violet]].<ref name="autogenerated2003">''Shorter Oxford English Dictionary'', 5th Edition, 2003.</ref> The aurora borealis imaged on the left shows blue, violet, and purple colors with the Milky Way in the background. The second aurora on the right contains an intense violet band above the pink band. {{clear}} ==Blues== {{main|Radiation astronomy/Blues|Blue astronomy}} [[Image:Linear visible spectrum.svg|thumb|center|400px|Blue is between violet and green in the spectrum of visible light. Credit: [[commons:User:Gringer|Gringer]].]] [[Image:Color icon blue.svg|thumb|right|250px|These are various shades of blue. Credit: [[commons:User:Booyabazooka|Booyabazooka]].]] [[Image:RGB illumination.jpg|left|thumb|250px|Blue, green and red are [[w:additive colors|additive colors]]. All the colors you see on your computer screen are made by mixing them in different intensities. Credit: [[w:User:Bb3cxv|Bb3cxv]].]] [[Image:Blue aurora.jpg|thumb|right|250px|This is a blue aurora borealis that occurred over Iceland. Credit: Daniel Nelson.]] [[Image:Northern Lights Canada 1 Oct 2012.jpg|thumb|right|250px|The image contains an extensive blue aurora over Canada. Credit: Unknown, or unstated.]] [[Image:Micha- DSC0788 filtered 1393514536 lg.jpg|thumb|left|250px|This is a blue aurora with some purple at the lower left. Credit: Micha.]] '''Def.''' of the higher-frequency region of the part of the electromagnetic spectrum which is relevant in the specific observation is called '''blue'''. '''Def.''' the colour of the clear sky or the deep sea, between green and violet in the visible spectrum, and one of the primary additive colours for transmitted light; the colour obtained by subtracting red and green from white light using magenta and cyan filters; or any colour resembling this is called '''blue'''. '''Blue''' is the colour of the clear sky and the deep sea.<ref name=Webster1962>See ''Webster's New World Dictionary of the American Language'', College Edition, 1962.</ref> {{lang|fr|"De la couleur du ciel sans nuages, de l'azur"}}<ref name=LaRousse>{{ cite book |author= |title=Le Petit Larousse illustré 1997 |publisher=Librairie Larousse |location= |date=1996 |editor= |pages=1784 |url=http://books.google.com/books?id=ZWSemgEACAAJ&hl=en&sa=X&ei=P72mUauzBoba9ASxhYHoAQ&ved=0CFQQ6AEwDw |arxiv= |bibcode= |doi= |pmid= |isbn=2033011976 |accessdate=2013-05-28 }}</ref> {{Shades of blue}} The image on the right shows blue aurora borealis that occurred over Iceland. The second image down on the right shows an extensive blue aurora above the green over Canada. The image on the left shows an extensive blue aurora. {{clear}} ==Cyans== {{main|Radiation astronomy/Cyans|Cyan astronomy}} [[Image:Black body.svg|thumb|right|250px|Planck's equation (colored curves) accurately describes black body radiation. Credit: .]] [[Image:Pallete_of_color_icon_cyan.png|thumb|right|250px|The color box shows some of the variations of cyan. Credit: .]] [[Image:White Aqua Aurora Finland.jpg|thumb|right|250px|This is a white and aqua aurora over Finland. Credit: Unknown, or unstated.]] [[Image:Cyan aurora.jpg|thumb|right|250px|This aurora borealis is a greenish-blue or cyan. Credit: beautiful-portals.tumblr.com.]] [[Image:Northern Lights Michigan USA Nov 2012.jpg|thumb|left|250px|This aurora contains a band of aqua-blue. Credit: Unknown, or unstated.]] Cyan light has a wavelength of between 490 and 520 nanometers, between the wavelengths of blue and green.<ref>[http://physics.about.com/od/lightoptics/a/vislightspec.htm About.com - Physics] About.Com - Physics (Retrieved 6-18-2013)</ref> '''Planck's equation''' describes the amount of spectral radiance at a certain wavelength radiated by a black body in thermal equilibrium. In terms of wavelength (λ), Planck's equation is written as :<math>B_\lambda(T) =\frac{2 hc^2}{\lambda^5}\frac{1}{ e^{\frac{hc}{\lambda k_\mathrm{B}T}} - 1}</math> where ''B'' is the spectral radiance, ''T'' is the absolute temperature of the black body, ''k''_B is the Boltzmann constant, ''h'' is the Planck constant, and ''c'' is the speed of light. This form of the equation contains several constants that are usually not subject to variation with wavelength. These are ''h'', ''c'', and ''k''_B. They may be represented by simple coefficients: c1 = 2''h'' ''c''² and c2 = ''h'' ''c''/''k''_B. By setting the first partial derivative of Planck's equation in wavelength form equal to zero, iterative calculations may be used to find pairs of (λ,T) that to some significant digits represent the peak wavelength for a given temperature and vice versa. : <math>\frac{\partial B}{\partial \lambda} = \frac{c1}{\lambda^6}\frac{1}{ e^{\frac{c2}{\lambda T}} - 1}[\frac{c2}{\lambda T}\frac{1}{ e^{\frac{c2}{\lambda T}} - 1}e^{\frac{c2}{\lambda T}} - 5] = 0.</math> Or, : <math>\frac{c2}{\lambda T}\frac{1}{ e^{\frac{c2}{\lambda T}} - 1}e^{\frac{c2}{\lambda T}} - 5 = 0.</math> : <math>\frac{c2}{\lambda T}\frac{1}{ e^{\frac{c2}{\lambda T}} - 1}e^{\frac{c2}{\lambda T}} = 5.</math> Use c2 = 1.438833 cm K. For a star to have a peak in the cyan, iterative calculations using the last equation yield the pairs: approximately (476 nm, 6300 K) and (495 nm, 6100 K). Although Planck's equation is not an exact fit to a star's spectral radiance, it may be close enough to suggest if a star is an astronomical cyan source. '''Electric blue''' is a color close to cyan that is a representation of the color of [[w:lightning|lightning]], an [[w:electric spark|electric spark]], and [[w:neon sign|argon sign]]s. The [[w:electric blue glow|electric blue glow]] of [[w:electricity|electricity]] results from the [[w:spectral|spectral]] emission of the [[w:excited state|excited]] ionized atoms (or excited molecules) of [[w:air|air]] (mostly [[w:oxygen|oxygen]] and [[w:nitrogen|nitrogen]]) falling back to unexcited states, which happens to produce an abundance of electric blue light. This is the reason electrical sparks in air, including lightning, appear electric blue. It is a coincidence that the color of [[w:Cherenkov radiation|Cherenkov radiation]] and light emitted by ionized air are a very similar blue despite their very different methods of production. Aero blue is a fluorescent cyan color. The word [cerulean] is probably derived from the [[Latin]] word ''caeruleus'', "dark blue, blue or blue-green", which in turn probably derives from ''caelulum'', diminutive of ''caelum'', "heaven, sky".<ref>[http://www.etymonline.com/index.php?search=cerulean&searchmode=none ''Cerulean'', Online Etymology Dictionary]</ref> Natural gas (methane) has a cyan colored flame when burned with a mixture of air. This is a white aurora at the lower center and an aqua aurora in the upper part of the image on the right. The aurora borealis on the left is probably the usual green aurora but appears greenish-blue or cyan. {{clear}} ==Greens== {{main|Radiation astronomy/Greens|Green astronomy}} [[Image:Color icon green.svg|thumb|right|250px|These color squares show a variety of greens. Credit: [[commons:User:FedericoMP|FedericoMP]].]] [[Image:RGB illumination.jpg|left|thumb|250px|Green, blue and red are [[w:additive colors|additive colors]]. All the colors you see on your computer screen are made by mixing them in different intensities. Credit: [[w:User:Bb3cxv|Bb3cxv]].]] [[Image:Leavessnipedale.jpg|thumb|right|250px|The word ''green'' has the same Germanic root as the words for ''grass'' and ''grow'' and is a common color reflected by leaves on Earth. Credit: [[commons:User:The cat|The cat]].]] [[Image:Azurite-Malachite-23ub.jpg|thumb|right|250px|Malachite is a mineral occurring on Earth, like many greens, is colored by the presence of copper, specifically by basic copper(II) carbonate.<ref name=Malachite>{{ cite book | url = http://webexhibits.org/pigments/indiv/overview/malachite.html | title = Malachite | publisher = WebExhibits | date = 2001 | accessdate = 2007-12-08 }}</ref> Credit: [[commons:User:Rob Lavinsky|Rob Lavinsky]].]] [[Image:PIA12758 Helene crop.jpg|left|thumb|250px|Cassini imaged the surface of Saturn's moon Helene as the spacecraft flew by the moon on Jan. 31, 2011. Credit: NASA / Jet Propulsion Lab / Space Science Institute.]] [[Image:Green Aurora Borealis Alaska.jpg|thumb|right|250px|The image shows Aurora Borealis at its finest in Alaska. Credit: jewishbrick.]] [[Image:Stpatties green aurora.jpg|thumb|left|250px|This green aurora appears to have a black aurora at its center. Credit: Sebastian Saarloos.]] [[Image:Northern Lights New Urenroe Russia.png|thumb|right|250px|This green aurora has the appearance of coming at the viewer. Credit: Unknown, or unstated.]] [[Image:Green loop aurora.jpg|thumb|left|250px|This is a loop aurora over Summit, Alaska. Credit: Jason Ahrns.]] Green has a wavelength range of approximately 520–570 nm, a frequency range of ~575–525 THz, with color coordinates of (0, 255, 0) and a hexagonal triplet of #00FF00 from [[w:sRGB color space|sRGB]] source of sRGB approximation to NCS S 2060-G.<ref name=NCScolor>The sRGB values are taken by converting the NCS color 2060-G using the "NCS Navigator" tool at [http://www.ncscolour.com/ the NCS website].</ref> '''Def.''' the [[wikt:colour|colour]] of growing [[wikt:foliage|foliage]], as well as other [[wikt:plant|plant]] [[wikt:cell|cell]]s containing [[wikt:chlorophyll|chlorophyll]]; the colour between yellow and blue in the visible spectrum; one of the primary additive colour for transmitted light; the colour obtained by subtracting red and blue from white light using cyan and yellow filters is called '''green'''. "...in nature chiefly conspicuous as the colour of growing herbage and leaves..."<ref name=Oxford/> '''Green''' is the color of [[w:emerald|emerald]]s, [[w:jade|jade]], and growing [[w:grass|grass]].<ref name=Oxford>(Oxford English Dictionary, 2nd Edition, Clarendon Press, Oxford, 1989.) See also first definition in ''Webster's New World Dictionary of the American Language'', The World Publishing Company, New York, 1962.</ref> In the continuum of colors of [[w:visible spectrum|visible light]] it is located between [[w:yellow|yellow]] and [[w:blue|blue]]. Green is the color most commonly associated with [[w:nature|nature]] and the [[w:environmental movement|environmental movement]], [[w:Islam|Islam]], [[w:spring (season)|spring]], [[w:hope|hope]] and [[w:envy|envy]].<ref name=Heller>Eva Heller, ''Psychologie de la couleur- effets et symboliques''. pg. 87-104</ref> Green is the color you see when you look at light with a [[w:wavelength|wavelength]] of roughly 520–570 [[w:nanometre|nanometer]]s. It is one of the three [[w:additive colors|additive colors]], along with red and blue, which are combined on computer screens and color televisions to make all other colors. In the [[w:subtractive color|subtractive color]] system, used in printing, it is not a [[w:primary color|primary color]], but is created out of a mixture of [[w:yellow|yellow]] and [[w:blue|blue]], or yellow and [[w:cyan|cyan]]. On the [[w:HSV color space|HSV color wheel]], also known as the [[:File:RBG color wheel.svg|RGB color wheel]], the [[w:Complementary color|complement]] of green is [[w:magenta|magenta]]; that is, a [[w:purple|purple]] color corresponding to an equal mixture of [[w:red|red]] and [[w:blue|blue]] light. On a [[w:color wheel|color wheel]] based on traditional color theory ([[w:RYB|RYB]]), the [[w:complementary color|complementary color]] to green is considered to be [[w:red|red]].<ref name = wheel>{{ cite book | title =Glossary Term: Color wheel | publisher =Sanford Corp. | date =2005 | accessdate = 2007-11-22 |url = http://web.archive.org/web/20071102211428/http://www.sanford-artedventures.com/study/g_color_wheel.html }}</ref> The [[w:perception|perception]] of greenness (in opposition to redness forming one of the [[w:opponent process|opponent]] mechanisms in human [[w:color vision|color vision]]) is evoked by light which triggers the medium-wavelength ''M'' [[w:cone cell|cone cell]]s in the eye more than the long-wavelength ''L'' cones. Light which triggers this greenness response more than the yellowness or blueness of the other color opponent mechanism is called green. A green light source typically has a spectral power distribution dominated by energy with a wavelength of roughly 487–570&nbsp;[[w:Nanometre|nm]]. More specifically, "blue green" 487–493 nm, "bluish green" 493–498 nm, "green" 498–530 nm, "yellowish green" 530–559 nm, "yellow green" 559–570 nm.<ref name=Kelly>Kenneth L. Kelly (1943). "Color Designations for Lights". Journal of the Optical Society of America '''33'''(11). 627–632.</ref> '''Green earth''' is a natural pigment. It s composed of clay colored by [[w:iron oxide|iron oxide]], magnesium, [[w:aluminum silicate|aluminum silicate]], or potassium. Large deposits were found in the South of France near Nice, and in Italy around Verona, on Cyprus, and in Bohemia. The clay was crushed, washed to remove impurities, then powdered. It was sometimes called Green of Verona.<ref name=Varichon>Anne Varichon (2000), {{lang|fr|Couleurs- pigments et teintures dans les mains des peoples.}} Pg. 210-211.</ref> "Cassini imaged [on the left] the surface of Saturn's moon Helene as the spacecraft flew by the moon on Jan. 31, 2011."<ref name=Porco>{{ cite book |author=C. Porco |title=Flying by Helene |publisher=NASA's Science Mission Directorate |location=Washington, D.C. USA |date=31 January 2011 |url=http://www.ciclops.org/view/6723/Flying_by_Helene?js=1 |accessdate=2016-11-06 }}</ref> "This small moon leads Dione by 60 degrees in the moons' shared orbit. Helene is a "Trojan" moon of Dione, named for the Trojan asteroids that orbit 60 degrees ahead of and behind Jupiter as it circles the Sun."<ref name=Porco/> "This view looks toward the leading hemisphere of Helene (33 kilometers, 21 miles across). North on Helene is up and rotated 2 degrees to the left."<ref name=Porco/> "The image was taken with the Cassini spacecraft narrow-angle camera using a combination of spectral filters sensitive to wavelengths of polarized green light centered at 617 and 568 nanometers. The view was obtained at a distance of approximately 31,000 kilometers (19,000 miles) from Helene and at a Sun-Helene-spacecraft, or phase, angle of 65 degrees. Scale in the original image was 187 meters (612 feet) per pixel. The image was contrast enhanced and magnified by a factor of 1.5 to enhance the visibility of surface features."<ref name=Porco/> This aurora borealis on the right that occurred over Alaska is almost all green. The second green aurora down on the right is over Urenroe, Russia. It shows the radiation pattern of being directly overhead. "Last night Earth experienced a geomagnetic storm and aurora were visible in the Northern U.S. states. [This image on the left] of [an] aurora [was] captured on March 17, 2015, around 5:30 a.m. EDT in Donnelly Creek, Alaska by Sebastian Saarloos. These aurora might have been caused by the fast solar wind streaming from two solar coronal holes."<ref name=ZellPatrick>{{ cite book |author=Holly Zell |title=St. Patrick's Day Green Aurora |publisher=NASA |location=Washington, DC USA |date=30 July 2015 |url=http://www.nasa.gov/content/goddard/st-patricks-day-green-aurora |accessdate=2015-11-29 }}</ref> An earlier green aurora is shown second down on the left from apparently January 2015. {{clear}} ==Yellows== {{main|Radiation astronomy/Yellows|Yellow astronomy}} [[Image:Color icon yellow.svg|thumb|right|250px|These are examples of the various colors of yellow. Credit: [[commons:User:Badseed|Badseed]].]] [[Image:PlanckianLocusWithYellowComplements.png|thumb|left|250px|Complements of yellow have a dominant wavelength in the range 380 to 480&nbsp;nm. The green lines show several possible pairs of complementary colors. Credit: .]] [[Image:Lascaux2.jpg|thumb|right|250px|The image is of a horse colored with [[w:yellow ochre|yellow ochre]]. from [[w:Lascaux|Lascaux]] cave. Credit: Cro-Magnon peoples.]] [[Image:Zwei Bäume im Rapsfeld, blauer Himmel.jpg|thumb|left|250px|This shows a field of yellow rapeseed. Credit: [http://www.publicdomainpictures.net/browse-author.php?a=1 Petr Kratochvil].]] [[Image:Yellow and cyan aurora.jpg|thumb|right|250px|This photo of yellow and green auroras shows convincingly that yellow is a distinctive result of the auroral process. Credit: Belinda Witzenhausen.]] [[Image:NorthernLightsUnusualNewUrengoiRussia.jpg|thumb|left|250px|This image captures an unusual aurora from Urengoi, Russia. Credit: Unknown.]] [[Image:Alaska2014ColorsVibrations.jpg|thumb|left|250px|This aurora image from Alaska shows distinctive yellow associated with the horizon. Credit: Unknown.]] [[Image:Yellow Aurora Alaska 2014.jpg|thumb|left|250px|This is another aurora from Alaska containing yellow. Credit: Unknown.]] [[Image:Beaghmoreaurorafeb27th014-13.jpg|thumb|right|250px|This orange and yellow aurora occurred above Beaghmore Stone Circles. Credit: Martin McKenna.]] "To see day objects with most distinctness, I require a less concave lens by one degree than for seeing the stars best by night, the cause of which seems to be, that the bottom of the eye being illuminated by the day objects, and thereby rendered a light ground, obscures the fainter colours blue indigo and violet in the circle of dissipation, and therefore the best image of the object will be found in the focus of the bright '''yellow rays''', and not in that of the mean refrangible ones, or the dark green, agreeable to Newton's remark, and consequently nearer the retina of a short-sighted person; but the parts of the retina surrounding the circle of dissipation of a star being in the dark, the fainter colours, blue, indigo, and violet, will have some share in forming the image, and consequently the focus will be shorter."<ref name=Maskelyne>{{ cite journal |author=Nevil Maskelyne |title=An Attempt to Explain a Difficulty in the Theory of Vision, Depending on the Different Refrangibility of Light |journal=Philosophical Transactions of the Royal Society of London |month=June 18 |year=1789 |volume=79 |issue= |pages=256-64 |url=http://www.jstor.org/stable/106696 |arxiv= |bibcode= |doi= |pmid= |accessdate=2013-09-13 }}</ref> Bold added. "The error due to color loses its disturbing effect because the photographic plate is not sensitive for the red and yellow rays, while the photographically active rays of shorter wave-length are well united by the objective."<ref name=Hartmann>{{ cite journal |author=J. Hartmann |title=An Improvement of the Foucault Knife-Edge Test in the Investigation of Telescope Objectives |journal=The Astrophysical Journal |month=May |year=1908 |volume=27 |issue= |pages=254-9 |url=http://adsabs.harvard.edu/abs/1908ApJ....27..254H |arxiv= |bibcode=1908ApJ....27..254H |doi=10.1086/141552 |pmid= |accessdate=2013-09-13 }}</ref> "The star brightness increase in 1964 was considerably different in yellow and blue rays. ... Extensive tables and graphs represent the mean photographic and photovisual curve of V1329 Cyg observed in Moscow and Odessa, brightness curves in blue and yellow rays, brightness increases, and brightness minima before and after an outburst."<ref name=Arkhipova>{{ cite journal |author=V. P. Arkhipova; O. E. Mandel |title=Photographic observations of V1329 CYG |journal=Pis'ma v Astronomicheskii Zhurnal |month=April |year=1991 |volume=17 |issue=04 |pages=359-67 |url=http://adsabs.harvard.edu/abs/1991PAZh...17..359A |arxiv= |bibcode=1991PAZh...17..359A |doi= |pmid= |accessdate=2013-09-13 }}</ref> "The GE Reveal bulb is marketed as the bulb that is made to “specially filter out yellow rays that hide life's true colors.” This is accomplished by the use of neodymium in the glass."<ref name=Birriel>{{ cite journal |author=Jennifer J. Birriel |title=Demonstrating Absorption Spectra Using Commercially Available Incandescent Light Bulbs |journal=Astronomy Education Review |month=September |year=2008 |volume=7 |issue=2 |pages=147-57 |url=http://link.aip.org/link/?AERSCZ/7/147/1 |arxiv= |bibcode= |doi=10.3847/AER2008035 |pmid= |accessdate=2013-09-13 }}</ref> '''Def.''' the colour of [[wikt:gold|gold]] or [[wikt:butter|butter]]; the [[wikt:colour|colour]] obtained by mixing [[wikt:green|green]] and [[wikt:red|red]] light, or by subtracting [[wikt:blue|blue]] from [[wikt:white|white]] light is called '''yellow'''. '''Def.''' a bright yellow colour, resembling the metal gold is called {| class="wikitable" style="text-align:center; margin:0.5em auto; width:auto; margin-left:1em;" |- | style="background:#FFD700;"|'''gold'''. |} Yellow, in the form of [[w:yellow ochre|yellow ochre]] pigment made from clay, was one of the first colors used in prehistoric cave art. The cave of [[w:Lascaux|Lascaux]] has an image of a horse colored with yellow estimated to be 17,300 years old. [[w:Shades of yellow|Shades of yellow]] contains a more diverse set of yellow or yellow-like colors. Any doubt that a yellow aurora can occur should be put to rest with the image on the right. The image on the left shows individual rays of radiation apparently impacting an upper atmospheric layer to produce a bead-like pattern. The second image down on the left shows yellow of an aurora near the horizon with apparently the midnight Sun off to the left. The third image on the left contains yellow aurora that is closer to true yellow. The second image down on the right shows a yellow aurora following the skyline with an orange aurora above. "On February 25th 2014 a violent X4.9-class solar flare erupted from a large sunspot group which had just rotated into view around the SE limb of the solar disk. The CME it unfurled was a massive full halo feature in the form of an expanding cloud of highly charged particles and plasma en route to the inner planets at a staggering velocity of over 2000km/sec. At this speed the CME would sweep across 93 million miles of space and impact planet Earth in only two days. However there was bad news as the source of this flare - and subsequent CME event - was located so close to the limb of the sun that the CME was very unlikely to impact Earth because it was located too far from the meridian and hence was not termed geoeffective which meant there was no chance of any Earth directed component at all. A few hours later a more detailed look by spaceweather scientists followed which offered some cautious optimism for in some of their forecasting models there was a slight chance that the CME could hit Earth a glancing blow with a possibility of minor geomagnetic storms on Feb 27th however the consensus was that the CME would probably miss entirely or if there was a hit then it wasn't expected to be significant."<ref name=McKenna>{{ cite book |author=Martin McKenna |title=Beaghmore Stone Circles & Lough Fea Crimson Geomagnetic Storm |publisher=Nightskyhunter |location=Ireland |date=27 February 2014 |url=http://www.nightskyhunter.com/Beaghmore%20Stone%20Circles%20Aurora%20-%20Feb%2027th%202014.html |accessdate=1 December 2015 }}</ref> "The B_z is the secret to a good aurora show, this is [where] its at, the B_z (pronounced Bee Sub Zee) is a value indicating the tilt of the Interplanetary Magnetic Field or IMF. If the B_z is N then you can forget about a good show, even if the KP is good it won't make a difference, however if the B_z tilts S then the Earth and Sun's magnetic fields become aligned and in effect what you are doing is opening a gate way [...] allowing the highly charged solar particles to interact with the Earth's magnetosphere undisturbed - this open channel will manifest as a strong geomagnetic storm. The fact that it was - 20 got me extremely excited, this value meant the aurora was going to be strong and would be seen from far more southern latitudes than usual."<ref name=McKenna/> {{clear}} ==Oranges== {{main|Radiation astronomy/Oranges|Orange astronomy}} [[Image:Kleurenovergang van rood naar geel.png|thumb|center|300px|In traditional colour theory, orange is a range of colours between red and yellow. Credit: [[:nl:user:Wilinckx|Wilinckx]].]] [[Image:Color icon orange v2.svg|thumb|right|250px|The box shows nine variations of the color orange. Credit: .]] [[Image:Aurora Borealis from Finland.jpg|thumb|right|250px|This is an aurora borealis photographed as occurring above Finland. Credit: Pekka Parviainen.]] [[Image:Northern Lights New York Oct 2011.jpg|thumb|right|250px|This is an orange aurora over New York. Credit: Unknown, or unstated.]] [[Image:Aurora-borealis-maine.jpg|thumb|left|250px|This is an extensively orange aurora that occurred over Maine. Credit: Unknown, or unstated.]] The orange portion of the visible spectrum is from 590 to 620 nm in wavelength. In optics, orange is the colour seen by the eye when looking at light with a wavelength between approximately 585–620&nbsp;nm. It has a hue of 30° in HSV colour space. '''Def.''' the [[wikt:colour|colour]] of a ripe orange (the fruit); a color midway between red and yellow is called '''orange'''. {{Shades of orange}} The aurora imaged on the right occurred over Finland in early October 2002. Note the pastel orange colors. The second image down on the right shows a reddish-orange aurora observed over New York in October 2011. To compare and contrast with the orange-containing aurora on the right is the extensively orange aurora on the left which also occurred over Finland. {{clear}} ==Reds== {{main|Radiation astronomy/Reds|Red astronomy}} [[Image:Red aurora.jpg|thumb|right|250px|This is a red aurora borealis. Credit: Isarl.]] [[Image:Red aurora Independence MO.jpg|thumb|left|250px|A view of an all-red aurora is captured in Independence, Mo., on October 24, 2011. Credit: Tobias Billings.]] In [[w:Wavelength|wavelength]]s, red astronomy covers 620 - 750 [[w:Nanometer|nm]]. Infrared or red radiation from a common household radiator or electric heater is an example of thermal radiation, as is the heat emitted by an operating incandescent light bulb. Thermal radiation is generated when energy from the movement of charged particles within atoms is converted to electromagnetic radiation. '''Infrared''' ('''IR''') light is [[electromagnetic radiation]] with longer [[w:wavelength|wavelength]]s than those of [[w:Light|visible light]], extending from the nominal red edge of the visible spectrum at 700 [[w:nanometre|nanometre]]s (nm) to 1&nbsp;mm. This range of wavelengths corresponds to a [[w:Frequency spectrum|frequency]] range of approximately 430&nbsp;[[w:THz|THz]] down to 300&nbsp;[[w:GHz|GHz]],<ref name=Liew>{{ cite book |author=S. C. Liew |url=http://www.crisp.nus.edu.sg/~research/tutorial/em.htm |title=Electromagnetic Waves |publisher=Centre for Remote Imaging, Sensing and Processing |accessdate=2006-10-27 }}</ref> and includes most of the [[w:thermal radiation|thermal radiation]] emitted by objects near room temperature. Infrared light is emitted or absorbed by [[w:molecule|molecule]]s when they change their [[w:Infrared spectroscopy|rotational-vibrational]] movements. '''Far-red''' light is light at the extreme red end of the visible spectrum, between red and infra-red light. Usually regarded as the region between 710 and 850&nbsp;nm wavelength, it is dimly visible to some [human] eyes. On the right is an example of a red aurora borealis. "A coronal mass ejection (CME) shot off the sun late in the evening of October 21 [2011] and hit Earth on October 24 at about 2 PM ET. The CME caused strong magnetic field fluctuations near Earth's surface – technically, this level of magnetic fluctuation rated a 7 out of 9 on what is called the "KP index" – that resulted in aurora that could be seen in the US as far south as Alabama. This image [on the left] was captured in Independence, Mo. Such completely red aurora are not as common as green aurora, however they can happen during strong solar activity and they occur a little more often at low latitudes such as where this was taken."<ref name=Fox>{{ cite book |author=Karen C. Fox |title=Red Sky On Earth Results From Solar Storm |publisher=NASA's Goddard Space Flight Center |location=Greenbelt, Maryland USA |date=October 2011 |url=http://www.ineffableisland.com/2011/10/red-sky-on-earth-results-from-solar.html |accessdate=18 November 2015 }}</ref> "The strength, speed, and mass of this CME also pushed the boundary of Earth's magnetic fields – a boundary known as the magnetopause – from its normal position at about 40,000 miles away from Earth in to about 26,000 miles. This is the area where spacecraft in geosynchronous orbit reside, so these spacecraft were briefly orbiting outside of Earth's normal environment, traveling through material and magnetic fields far different from usual."<ref name=Fox/> {{clear}} ==Infrareds== {{main|Radiation astronomy/Infrareds|Infrared astronomy}} [[Image:A Quarter Century of Infrared Astronomy.jpg|right|thumb|250px|Infrared astronomy, especially from space, explores up a vast portion of the spectrum beyond the red end of visible light. Credit: IRAS / ISO / 2MASS / Spitzer.]] The wavelength of infrared light ranges from 0.75 to 300 micrometers. Infrared falls in between visible radiation, which ranges from 380 to 750 nanometers, and submillimeter waves. Infrared rays can be emitted, fluoresced, or reflected by an astronomical object. '''Def.''' [[wikt:electromagnetic|electromagnetic]] [[wikt:radiation|radiation]] of a [[wikt:wavelength|wavelength]] longer than [[wikt:visible light|visible light]], but shorter than [[wikt:microwave|microwave]] radiation, having a wavelength between 700 [[wikt:nm|nm]] and 1 mm is called '''infrared'''. '''Def.''' [[wikt:electromagnetic|[e]lectromagnetic]] radiation having a wavelength approximately between 1 [[wikt:micrometre|micrometre]] and 1 [[wikt:millimetre|millimetre]]; perceived as [[wikt:heat|heat]] is called '''infrared radiation'''. Astronomers typically divide the infrared spectrum as follows:<ref>{{ cite book |author=IPAC Staff |url=http://www.ipac.caltech.edu/Outreach/Edu/Regions/irregions.html |title=Near, Mid and Far-Infrared |publisher=NASA ipac |accessdate=4 April 2007 }}</ref> {| class="wikitable" |- ! style="width:100pt; text-align:left;"| Designation ! style="width:100pt; text-align:center;"| Abbreviation ! style="width:150pt; text-align:center;"| Wavelength |- |align="left"| Near Infrared | style="text-align:center;"| NIR | style="text-align:center;"| (0.7&ndash;1) to 5&nbsp;µm |- |align="left"| Mid Infrared | style="text-align:center;"| MIR | style="text-align:center;"| 5 to (25&ndash;40)&nbsp;µm |- |align="left"| Far Infrared | style="text-align:center;"| FIR | style="text-align:center;"| (25&ndash;40) to (200&ndash;350)&nbsp;µm. |} These are the approximate ranges for photon energies of the infrared bands: {| class="wikitable" |'''Division Name''' |'''Wavelength''' |'''Photon Energy''' |- |Near-infrared |0.75-1.4&nbsp;µm | 0.9-1.7 eV |- |Short-wavelength infrared | 1.4-3&nbsp;µm | 0.4-0.9 eV |- |Mid-wavelength infrared | 3-8&nbsp;µm | 150-400 meV |- | Long-wavelength infrared | 8–15&nbsp;µm | 80-150 meV |- |Far infrared | 15 - 1,000&nbsp;µm | 1.2-80 meV |- |} <table width=100% cellspacing=4 cellpadding=4 class="wikitable"> <tr> <th valign=bottom align=left>Wavelength range<br><small>([[w:micrometre|micrometre]]s)</small></th> <th valign=bottom align=left>Astronomical bands</th> <th valign=bottom align=left>Telescopes</th> </tr> <tr> <td valign=top align=left>0.65 to 1.0</td> <td valign=top align=left>R and I bands</td> <td valign=top align=left>All major optical telescopes</td> </tr> <tr> <td valign=top align=left>1.1 to 1.4</td> <td valign=top align=left>J band</td> <td valign=top align=left>Most major optical telescopes and most dedicated infrared telescopes</td> </tr> <tr> <td valign=top align=left>1.5 to 1.8</td> <td valign=top align=left>H band</td> <td valign=top align=left>Most major optical telescopes and most dedicated infrared telescopes</td> </tr> <tr> <td valign=top align=left>2.0 to 2.4</td> <td valign=top align=left>K band</td> <td valign=top align=left>Most major optical telescopes and most dedicated infrared telescopes</td> </tr> <tr> <td valign=top align=left>3.0 to 4.0</td> <td valign=top align=left>L band</td> <td valign=top align=left>Most dedicated infrared telescopes and some optical telescopes</td> </tr> <tr> <td valign=top align=left>4.6 to 5.0</td> <td valign=top align=left>M band</td> <td valign=top align=left>Most dedicated infrared telescopes and some optical telescopes</td> </tr> <tr> <td valign=top align=left>7.5 to 14.5</td> <td valign=top align=left>N band</td> <td valign=top align=left>Most dedicated infrared telescopes and some optical telescopes</td> </tr> <tr> <td valign=top align=left>17 to 25</td> <td valign=top align=left>Q band</td> <td valign=top align=left>Some dedicated infrared telescopes and some optical telescopes</td> </tr> <tr> <td valign=top align=left>28 to 40</td> <td valign=top align=left>Z band</td> <td valign=top align=left>Some dedicated infrared telescopes and some optical telescopes</td> </tr> <tr> <td valign=top align=left>330 to 370</td> <td valign=top align=left> </td> <td valign=top align=left>Some dedicated infrared telescopes and some optical telescopes</td> </tr> <tr> <td valign=top align=left>450</td> <td valign=top align=left>submillimeter</td> <td valign=top align=left>Submillimeter telescopes</td> </tr> </table> The infrared band may be divided up based on the response of various detectors:<ref name="Miller">Miller, ''Principles of Infrared Technology'' (Van Nostrand Reinhold, 1992), and Miller and Friedman, ''Photonic Rules of Thumb'', 2004. isbn=9780442012106 </ref> * Near infrared: from 0.7 to 1.0 &nbsp;µm (from the approximate end of the response of the [[w:human eye|human eye]] to that of silicon). * Short-wave infrared: 1.0 to 3 &nbsp;µm (from the cut off of silicon to that of the MWIR atmospheric window. InGaAs covers to about 1.8 &nbsp;µm; the less sensitive lead salts cover this region. * Mid-wave infrared: 3 to 5 &nbsp;µm (defined by the atmospheric window and covered by [[w:Indium antimonide|indium antimonide]] [InSb] and [[w:HgCdTe|HgCdTe]] and partially by [[w:lead selenide|lead selenide]] [PbSe]). * Long-wave infrared: 8 to 12, or 7 to 14 &nbsp;µm: the atmospheric window (Covered by HgCdTe and [[w:microbolometer|microbolometer]]s). * Very-long wave infrared (VLWIR): 12 to about 30 &nbsp;µm, covered by doped silicon. A commonly used sub-division scheme is:<ref name="Byrnes">{{ cite book |author=James Byrnes |title=Unexploded Ordnance Detection and Mitigation |publisher=Springer |date=2009 |pages=21–22 |isbn=9781402092527 }}</ref> {| class="wikitable" |'''Division Name''' |'''Abbreviation''' |'''Wavelength''' |'''Characteristics''' |- |'''Near-infrared''' |NIR, IR-A ''[[w:DIN|DIN]]'' |0.75-1.4&nbsp;µm | Defined by the water absorption, and commonly used in [[w:fiber optic|fiber optic]] telecommunication because of low attenuation losses in the SiO₂ glass ([[w:silica|silica]]) medium. Image intensifiers are sensitive to this area of the spectrum. Examples include night vision devices such as night vision goggles. |- |'''Short-wavelength infrared''' | SWIR, IR-B ''DIN'' | 1.4-3&nbsp;µm | Water absorption increases significantly at 1,450&nbsp;nm. The 1,530 to 1,560&nbsp;nm range is the dominant spectral region for long-distance telecommunications. |- |'''Mid-wavelength infrared''' |MWIR, IR-C ''DIN''. Also called intermediate infrared (IIR) | 3-8&nbsp;µm | In guided missile technology the 3-5&nbsp;µm portion of this band is the atmospheric window in which the homing heads of passive IR 'heat seeking' missiles are designed to work, homing on to the [[w:Infrared signature|Infrared signature]] of the target aircraft, typically the jet engine exhaust plume |- | '''Long-wavelength infrared''' | LWIR, IR-C ''DIN'' | 8–15&nbsp;µm | This is the "thermal imaging" region, in which sensors can obtain a completely passive picture of the outside world based on thermal emissions only and requiring no external light or thermal source such as the sun, moon or infrared illuminator. [[w:Forward-looking infrared|Forward-looking infrared]] (FLIR) systems use this area of the spectrum. This region is also called the "thermal infrared." |- |'''Far infrared''' | FIR | 15 - 1,000&nbsp;µm | (see also [[w:far-infrared laser|far-infrared laser]]). |- |} NIR and SWIR is sometimes called "reflected infrared" while MWIR and LWIR is sometimes referred to as "thermal infrared." Due to the nature of the blackbody radiation curves, typical 'hot' objects, such as exhaust pipes, often appear brighter in the MW compared to the same object viewed in the LW. {{clear}} ==Submillimeters== {{main|Radiation astronomy/Submillimeters|Submillimeter astronomy}} [[Image:Spectre Terahertz.svg|thumb|right|250px|Submillimeter waves lie at the far end of the infrared band, just before the start of the [[w:Microwave|microwave]] band. Credit: [[commons:User:Tatoute|Tatoute]].]] [[Image:Analyzing the Pieces of a Warped Galaxy.jpg|thumb|right|250px|This image composite shows a warped and magnified view of a galaxy discovered by the Herschel Space Observatory. Credit: ESA/NASA/JPL-Caltech/Keck/SMA.]] “'''[T]erahertz radiation''' refers to [[w:electromagnetic wave|electromagnetic wave]]s propagating at [[w:frequency|frequencies]] in the [[w:Hertz#SI prefixed forms of hertz|terahertz]] range. It is synonymously termed '''submillimeter radiation''', '''terahertz waves''', '''terahertz light''', '''T-rays''', '''T-waves''', '''T-light''', '''T-lux''', '''THz'''. The term typically applies to electromagnetic radiation with frequencies between high-frequency edge of the [[w:microwave|microwave]] band, 300&nbsp;[[w:gigahertz|gigahertz]] (3 x 10¹¹ [[w:Hertz|Hz]]),"<ref name=Hankwang>{{ cite book |author=[[w:User:Hankwang|Hankwang]] |title=Terahertz radiation |date=October 31, 2008 |volume= |issue= |pages=1 |url=http://en.wikipedia.org/w/index.php?title=Terahertz_radiation&diff=248835142&oldid=248831987 |bibcode= |doi= |pmid= |accessdate=2012-08-05 }}</ref> and the long-wavelength edge of [[w:far-infrared|far-infrared]] light, 3000&nbsp;GHz (3 x 10¹² Hz or 3&nbsp;THz). In wavelengths, this range corresponds to 0.1&nbsp;mm (or 100&nbsp;[[w:Micro-|µ]]m) infrared to 1.0&nbsp;mm microwave. Terahertz radiation is emitted as part of the [[w:black body|black body]] radiation from anything with temperatures greater than about 10 [[w:kelvin|kelvin]]. While this thermal emission is very weak, [[w:Submillimetre astronomy|observations at these frequencies]] are important for characterizing the cold 10-20K dust in the [[interstellar medium]] in the Milky Way galaxy, and in distant [[w:starburst galaxy|starburst galaxies]]. Telescopes operating in this band include the [[w:James Clerk Maxwell Telescope|James Clerk Maxwell Telescope]], the [[w:Caltech Submillimeter Observatory|Caltech Submillimeter Observatory]] and the [[w:Submillimeter Array|Submillimeter Array]] at the [[w:Mauna Kea Observatory|Mauna Kea Observatory]] in Hawaii, the [[w:BLAST (telescope)|BLAST]] balloon borne telescope, the [[w:Herschel Space Observatory|Herschel Space Observatory]], and the [[w:Heinrich Hertz Submillimeter Telescope|Heinrich Hertz Submillimeter Telescope]] at the [[w:Mount Graham International Observatory|Mount Graham International Observatory]] in Arizona. The [[w:Atacama Large Millimeter Array|Atacama Large Millimeter Array]], under construction, will operate in the submillimeter range. The opacity of the Earth's atmosphere to submillimeter radiation restricts these observatories to very high altitude sites, or to space. "This image composite [on the right] shows a warped and magnified view of a galaxy discovered by the Herschel Space Observatory, one of five such galaxies uncovered by the infrared telescope. The galaxy -- referred to as "SDP 81" -- is the yellow dot in the left image taken by Herschel. It can also be seen as the pink smudges in the right image, a composite of ground-based observations showing more detail."<ref name=WarpedGalaxy>{{ cite book |author=Spitzersteph |title=Analyzing the Pieces of a Warped Galaxy |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=November 4, 2010 |url=https://commons.wikimedia.org/wiki/File:Analyzing_the_Pieces_of_a_Warped_Galaxy.jpg |accessdate=2014-03-12 }}</ref> "Herschel was able to find the galaxy, which is buried in dust, because it happens to be positioned behind another galaxy (blue blob at right), which is acting like a cosmic lens to make it appear brighter. The gravity of the foreground galaxy is distorting and magnifying the distant galaxy's light, causing it to appear in multiple places, as seen as the pink smudges. The distant galaxy is so far away that its light took about 11 billion years to reach us."<ref name=WarpedGalaxy/> "Herschel couldn't detect the foreground galaxy, but astronomers were able to spot it in visible light using the W.M. Keck Observatory. Several follow-up observations by ground telescopes helped to get a better view of the distant galaxy. For example, the pink smudges at the right show wavelengths that are even longer than what Herschel sees in the submillimeter portion of the electromagnetic spectrum. Those observations were made by the Smithsonian Astrophysical Observatory's Submillimeter Array in Hawaii."<ref name=WarpedGalaxy/> {{clear}} ==Microwaves== {{main|Radiation astronomy/Microwaves|Microwave astronomy}} [[Image:Oldest Arctic Sea Ice is Disappearing.png|right|thumb|250px|The image shows sea ice coverage in 1980 (bottom) and 2012 (top). Credit: Josefino C. Comiso, NASA.]] '''Microwaves''', a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300&nbsp;MHz (0.3&nbsp;GHz) and 300&nbsp;GHz.<ref name=Pozer>Pozar, David M. (1993). ''Microwave Engineering'' Addison-Wesley Publishing Company. {{ISBN|0-201-50418-9}}.</ref> This broad definition includes both [ultra high frequency] UHF and [extremely high frequency] EHF (millimeter waves), and various sources use different boundaries.<ref name=googlegloss>http://www.google.com/search?hl=en&defl=en&q=define:microwave&ei=e6CMSsWUI5OHmQee2si1DQ&sa=X&oi=glossary_definition&ct=title</ref> In all cases, microwave includes the entire [super high frequency] SHF band (3 to 30&nbsp;GHz, or 10 to 1&nbsp;cm) at minimum, with [radio frequency] RF engineering often putting the lower boundary at 1&nbsp;GHz (30&nbsp;cm), and the upper around 100&nbsp;GHz (3 mm). {| class="wikitable" |+Microwave frequency bands !Letter Designation!!Frequency range!!Wavelength range!!Typical uses |- |L band||1&nbsp;to&nbsp;2&nbsp;GHz||15&nbsp;cm&nbsp;to&nbsp;30&nbsp;cm||military telemetry, GPS, mobile phones (GSM), amateur radio |- |S band||2&nbsp;to&nbsp;4&nbsp;GHz||7.5&nbsp;cm&nbsp;to&nbsp;15&nbsp;cm||weather radar, surface ship radar, and some communications satellites (microwave ovens, microwave devices/communications, [[radio astronomy]], mobile phones, wireless LAN, Bluetooth, ZigBee, GPS, amateur radio) |- |C band||4&nbsp;to&nbsp;8&nbsp;GHz||3.75&nbsp;cm&nbsp;to&nbsp;7.5&nbsp;cm||long-distance radio telecommunications |- |X band||8&nbsp;to&nbsp;12&nbsp;GHz||25&nbsp;mm&nbsp;to&nbsp;37.5&nbsp;mm||satellite communications, radar, terrestrial broadband, space communications, amateur radio |- |K_u band or P band||12&nbsp;to&nbsp;18&nbsp;GHz||16.7&nbsp;mm&nbsp;to&nbsp;25&nbsp;mm||satellite communications |- |K band||18&nbsp;to&nbsp;26.5&nbsp;GHz||11.3&nbsp;mm&nbsp;to&nbsp;16.7&nbsp;mm||radar, satellite communications, astronomical observations, automotive radar |- |K_a band||26.5&nbsp;to&nbsp;40&nbsp;GHz||5.0&nbsp;mm&nbsp;to&nbsp;11.3&nbsp;mm||satellite communications |- |Q band||33&nbsp;to&nbsp;50&nbsp;GHz||6.0&nbsp;mm&nbsp;to&nbsp;9.0&nbsp;mm||satellite communications, terrestrial microwave communications, [[radio astronomy]], automotive radar |- |U band||40&nbsp;to&nbsp;60&nbsp;GHz||5.0&nbsp;mm&nbsp;to&nbsp;7.5&nbsp;mm|| |- |V band||50&nbsp;to&nbsp;75&nbsp;GHz||4.0&nbsp;mm&nbsp;to&nbsp;6.0&nbsp;mm||millimeter wave radar research and other kinds of scientific research |- |W band||75&nbsp;to&nbsp;110&nbsp;GHz||2.7&nbsp;mm&nbsp;to&nbsp;4.0&nbsp;mm||satellite communications, millimeter-wave radar research, military radar targeting and tracking applications, and some non-military applications, automotive radar |- |F band||90&nbsp;to&nbsp;140&nbsp;GHz||2.1&nbsp;mm&nbsp;to&nbsp;3.3&nbsp;mm||SHF transmissions: [[Radio astronomy]], microwave devices/communications, wireless LAN, most modern radars, communications satellites, satellite television broadcasting, DBS, amateur radio |- |D band||110&nbsp;to&nbsp;170&nbsp;GHz||1.8&nbsp;mm&nbsp;to&nbsp;2.7&nbsp;mm||EHF transmissions: [[Radio astronomy]], high-frequency microwave radio relay, microwave remote sensing, amateur radio, directed-energy weapon, millimeter wave scanner |} The "oldest and thickest Arctic sea ice is disappearing at a faster rate than the younger and thinner ice at the edges of the ice cap. The rapid disappearance of older ice makes the Arctic Ocean's sea ice cap more vulnerable to further decline."<ref name=Comiso>{{ cite book |author=Josefino C. Comiso |title=Oldest Arctic Sea Ice is Disappearing |publisher=NASA |location=Washington, DC USA |date=1 March 2012 |url=http://earthobservatory.nasa.gov/IOTD/view.php?id=77270 |accessdate=2016-11-06 }}</ref> "Arctic multi-year ice “extent”—which includes all areas where at least 15 percent of the ocean surface is covered by multi-year ice—has been vanishing at a rate of –15.1 percent per decade [...] Over the same period, the “area” covered by multi-year ice—which discards open water among ice floes and focuses exclusively on regions that are completely covered—has been shrinking by –17.2 percent per decade."<ref name=Comiso/> "The images above show sea ice coverage in 1980 and 2012, as observed by passive microwave sensors on NASA’s Nimbus-7 satellite and by the Special Sensor Microwave Imager/Sounder (SSMIS) from the Defense Meteorological Satellite Program (DMSP). Multi-year ice is shown in bright white, while average sea ice cover is shown in light blue to milky white. The data shows the ice cover for the period of November 1 through January 31 in their respective years."<ref name=Comiso/> "The thickest “multi-year” ice survives through two or more summers, while young, seasonal ice forms over a winter and typically melts just as quickly as it formed. [...] “perennial” ice is all ice cover that has survived at least one summer. All multi-year ice is perennial ice, but not all perennial ice is multi-year ice. [...] perennial ice extent has been shrinking at a rate of –12.2 percent per decade, while its area is declining at a rate of –13.5 percent per decade. These numbers indicate that multiyear ice is declining faster than the perennial ice that surrounds it."<ref name=Comiso/> "As perennial ice has retreated over the past three decades, it has opened up new areas of the Arctic Ocean that could then be covered by seasonal ice. A larger volume of seasonal ice meant that a larger portion of it could make it through the summer to form second-year ice. This is likely the reason why the perennial ice cover, which includes second year ice, is not declining as rapidly as multiyear ice cover."<ref name=Comiso/> “The Arctic sea ice cover is getting thinner because it’s rapidly losing its thick component. At the same time, the surface temperature in the Arctic is going up, which results in a shorter ice-forming season. It would take a persistent cold spell for multi-year sea ice to grow thick enough again to be able to survive the summer melt season and reverse the trend.”<ref name=Comiso/> {{clear}} ==Radars== {{main|Radiation astronomy/Radars|Radar astronomy}} [[Image:ALSE AitkenHolo.jpg|right|thumb|250px|Two passages across the crater Aitken (16.8ºS, 173.4ºE) produced radar sounder images of the area. Credit: NASA.]] '''Radio waves''' are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Radio waves have frequencies from 300 Gigahertz GHz to as low as 3 Kilohertz kHz, and corresponding to wavelengths from 1 millimeter to 100 kilometers. {| class="wikitable" |+ '''Radar frequency bands''' |- style="background:#ccc;" !Band name!!Frequency range!!Wavelength range!!Notes |- |[[w:High frequency|HF]]||3–30 [[w:Megahertz|MHz]]||10–100 [[w:metre|m]]||Coastal radar systems, [[w:over-the-horizon radar|over-the-horizon radar]] (OTH) radars; 'high frequency' |- |[[w:VHF|VHF]]||30–300&nbsp;MHz||1–10 m||Very long range, ground penetrating; 'very high frequency' |- |P||<&nbsp;300&nbsp;MHz||>&nbsp;1&nbsp;m||'P' for 'previous', applied retrospectively to early radar systems; essentially HF + VHF |- |[[w:UHF|UHF]]||300–1000&nbsp;MHz||0.3–1 m||Very long range (e.g. [[w:Ballistic Missile Early Warning System|ballistic missile early warning]]), ground penetrating, foliage penetrating; 'ultra high frequency' |- |[[w:L band|L]]||1–2 [[w:Gigahertz|GHz]]||15–30 [[w:centimetre|cm]]||Long range air traffic control and [[w:Surveillance|surveillance]]; 'L' for 'long' |- |[[w:S band|S]]||2–4&nbsp;GHz||7.5–15&nbsp;cm||Moderate range surveillance, Terminal air traffic control, long-range weather, marine radar; 'S' for 'short' |- |[[w:C band|C]]||4–8&nbsp;GHz||3.75–7.5&nbsp;cm||Satellite transponders; a compromise (hence 'C') between X and S bands; weather; long range tracking |- |[[w:X band|X]]||8–12&nbsp;GHz||2.5–3.75&nbsp;cm||[[w:Missile|Missile]] guidance, [[w:marine radar|marine radar]], weather, medium-resolution mapping and ground surveillance; in the USA the narrow range 10.525&nbsp;GHz ±25&nbsp;MHz is used for airport radar; short range tracking. Named X band because the frequency was a secret during WW2. |- ||[[w:Ku band|K_u]]||12–18&nbsp;GHz||1.67–2.5&nbsp;cm||High-resolution, also used for satellite transponders, frequency under K band (hence 'u') |- |[[w:K band|K]]||18–24&nbsp;GHz||1.11–1.67&nbsp;cm||From [[w:German language|German]] ''kurz'', meaning 'short'; limited use due to absorption by [[w:water vapor|water vapour]], so K_u and K_a were used instead for surveillance. K-band is used for detecting clouds by meteorologists, and by police for detecting speeding motorists. K-band radar guns operate at 24.150 ± 0.100&nbsp;GHz. |- |[[w:Ka band|K_a]]||24–40&nbsp;GHz||0.75–1.11&nbsp;cm||Mapping, short range, airport surveillance; frequency just above K band (hence 'a') Photo radar, used to trigger cameras which take pictures of license plates of cars running red lights, operates at 34.300 ± 0.100&nbsp;GHz. |- |mm||40–300&nbsp;GHz||1.0–7.5&nbsp;[[w:millimetre|mm]] ||[[w:Millimetre band|Millimetre band]], subdivided as below. The frequency ranges depend on waveguide size. Multiple letters are assigned to these bands by different groups. These are from Baytron, a now defunct company that made test equipment. |- |[[w:V band|V]]||40–75&nbsp;GHz||4.0–7.5&nbsp;mm || Very strongly absorbed by atmospheric oxygen, which resonates at 60&nbsp;GHz. |- |[[w:W band|W]]||75–110&nbsp;GHz||2.7–4.0&nbsp;mm||Used as a visual sensor for experimental autonomous vehicles, high-resolution meteorological observation, and imaging. |} Two passages across the crater Aitken (16.8ºS, 173.4ºE) produced radar sounder images on the right of the area. The image shown here is two sections from the complete data set as processed after retrieval from the scientific instrument module (SIM) bay during the return flight from the Moon. {{clear}} ==Radios== {{main|Radiation astronomy/Radios|Radio astronomy}} [[Image:Jupiter radio.jpg|right|thumb|250px|Details in radiation belts close to Jupiter are mapped from measurements that NASA's Cassini spacecraft made. Credit: NASA Jet Propulsion Laboratory (NASA-JPL).]] '''Radio waves''' are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Radio waves have frequencies from 300 [Gigahertz] GHz to as low as 3 [Kilohertz] kHz, and corresponding wavelengths from 1 millimeter to 100 kilometers. "Details in radiation belts close to Jupiter are mapped from measurements that NASA's Cassini spacecraft made of radio emission from high-energy electrons moving at nearly the speed of light within the belts."<ref name=Wilson/> "The three views show the belts at different points in Jupiter's 10-hour rotation. A picture of Jupiter is superimposed to show the size of the belts relative to the planet. Cassini's radar instrument, operating in a listen-only mode, measured the strength of microwave radio emissions at a frequency of 13.8 gigahertz (13.8 billion cycles per second or 2.2 centimeter wavelength). The results indicate the region near Jupiter is one of the harshest radiation environments in the solar system."<ref name=Wilson/> "From Earth-based radio telescopes, the telltale radio emissions would be swamped out by heat-generated radio emissions from Jupiter's atmosphere, but Cassini was close enough to Jupiter in January 2001 to differentiate between the emissions from the radiation belts and those from the atmosphere."<ref name=Wilson/> "The belts appear to wobble as the planet turns because they are controlled by Jupiter's magnetic field, which is tilted in relation to the planet's poles."<ref name=Wilson>{{ cite book |author=Jim Wilson |title=Inner Radiation Belts of Jupiter |publisher=NASA |location=Washington, DC USA |date=27 February 2002 |url=http://www.nasa.gov/mission_pages/juno/multimedia/pia03478.html |accessdate=2016-11-06 }}</ref> {{clear}} ==See also== {{div col|colwidth=20em}} * [[Radiation astronomy/Colors|Color astronomy]] * [[Radiation astronomy/Opticals|Optical astronomy]] * [[Radiation/Astronomy|Radiation astronomy]] * [[Radiation astronomy/Superluminals|Superluminal astronomy]] * [[Radiation astronomy/Synchrotrons|Synchrotron astronomy]] * [[Radiation astronomy/Visuals|Visual astronomy]] {{Div col end}} ==References== {{reflist|2}} ==External links== <!-- footer templates --> {{tlx|Charge ontology}}{{tlx|Physics resources}}{{tlx|Principles of radiation astronomy}}{{Radiation astronomy resources}}{{Sisterlinks|Electromagnetics}} <!-- footer categories --> [[Category:Astrophysics/Lectures]] [[Category:Radiation/Lectures]] [[Category:Radiation astronomy/Lectures]] 6rp9t473ctgo3inngkj0u36eg2tlzy8 2 219126 2413951 2413792 2022-08-12T12:53:34Z ThaniosAkro 2805358 /* tables */ wikitext text/x-wiki <math>3</math> cube roots of <math>W</math> <math>W = 0.828 + 2.035\cdot i</math> <math>w_0 = 1.2 + 0.5\cdot i</math> <math>w_1 = \frac{-1.2 - 0.5\sqrt{3}}{2} + \frac{1.2\sqrt{3} - 0.5}{2}\cdot i</math> <math>w_2 = \frac{-1.2 + 0.5\sqrt{3}}{2} + \frac{- 1.2\sqrt{3} - 0.5}{2}\cdot i</math> <math>w_0^3 = w_1^3 = w_2^3 = W</math> <math></math> <math></math> <math>y = x^3 - x</math> <math>y = x^3</math> <math>y = x^3 + x</math> ===allEqual=== <math>y = f(x) = x^3</math> <math>y = f(-x)</math> <math>y = f(x) = x^3 + x</math> <math>x = p</math> <math>y = f(x) = (x-5)^3 - 4(x-5) + 7</math> {{Robelbox|title=[[Wikiversity:Welcome|Welcome]]|theme={{{theme|9}}}}} <div style="padding-top:0.25em; padding-bottom:0.2em; padding-left:0.5em; padding-right:0.75em;"> [[Wikiversity:Welcome|Wikiversity]] is a [[Wikiversity:Sister projects|Wikimedia Foundation]] project devoted to [[learning resource]]s, [[learning projects]], and [[Portal:Research|research]] for use in all [[:Category:Resources by level|levels]], types, and styles of education from pre-school to university, including professional training and informal learning. We invite [[Wikiversity:Wikiversity teachers|teachers]], [[Wikiversity:Learning goals|students]], and [[Portal:Research|researchers]] to join us in creating [[open educational resources]] and collaborative [[Wikiversity:Learning community|learning communities]]. To learn more about Wikiversity, try a [[Help:Guides|guided tour]], learn about [[Wikiversity:Adding content|adding content]], or [[Wikiversity:Introduction|start editing now]]. </div> ====Welcomee==== {{Robelbox|title=[[Wikiversity:Welcome|Welcome]]|theme={{{theme|9}}}}} <div style="padding-top:0.25em; padding-bottom:0.2em; padding-left:0.5em; padding-right:0.75em; background-color: #FFF800; "> [[Wikiversity:Welcome|Wikiversity]] is a [[Wikiversity:Sister projects|Wikimedia Foundation]] project devoted to [[learning resource]]s, [[learning projects]], and [[Portal:Research|research]] for use in all [[:Category:Resources by level|levels]], types, and styles of education from pre-school to university, including professional training and informal learning. We invite [[Wikiversity:Wikiversity teachers|teachers]], [[Wikiversity:Learning goals|students]], and [[Portal:Research|researchers]] to join us in creating [[open educational resources]] and collaborative [[Wikiversity:Learning community|learning communities]]. To learn more about Wikiversity, try a [[Help:Guides|guided tour]], learn about [[Wikiversity:Adding content|adding content]], or [[Wikiversity:Introduction|start editing now]]. </div> =====Welcomen===== {{Robelbox|title=|theme={{{theme|9}}}}} <div style="padding-top:0.25em; padding-bottom:0.2em; padding-left:0.5em; padding-right:0.75em; background-color: #FFFFFF; "> [[Wikiversity:Welcome|Wikiversity]] is a [[Wikiversity:Sister projects|Wikimedia Foundation]] project devoted to [[learning resource]]s, [[learning projects]], and [[Portal:Research|research]] for use in all [[:Category:Resources by level|levels]], types, and styles of education from pre-school to university, including professional training and informal learning. We invite [[Wikiversity:Wikiversity teachers|teachers]], [[Wikiversity:Learning goals|students]], and [[Portal:Research|researchers]] to join us in creating [[open educational resources]] and collaborative [[Wikiversity:Learning community|learning communities]]. To learn more about Wikiversity, try a [[Help:Guides|guided tour]], learn about [[Wikiversity:Adding content|adding content]], or [[Wikiversity:Introduction|start editing now]]. </div> <syntaxhighlight lang=python> # python code. if a == b == c == d == e == f == g == h == 0 :if a == b == c == d == e == f == g == h == 0 :if a == b == c == d == e == f == g == h == 0 :if a == b == c == d == e == f == g == h == 0 : pass </syntaxhighlight> {{Robelbox/close}} {{Robelbox/close}} {{Robelbox/close}} <noinclude> [[Category: main page templates]] </noinclude> {| class="wikitable" |- ! <math>x</math> !! <math>x^2 - N</math> |- | <code></code><code>6</code> || <code>-221</code> |- | <code></code><code>7</code> || <code>-208</code> |- | <code></code><code>8</code> || <code>-193</code> |- | <code></code><code>9</code> || <code>-176</code> |- | <code>10</code> || <code>-157</code> |- | <code>11</code> || <code>-136</code> |- | <code>12</code> || <code>-113</code> |- | <code>13</code> || <code></code><code>-88</code> |- | <code>14</code> || <code></code><code>-61</code> |- | <code>15</code> || <code></code><code>-32</code> |- | <code>16</code> || <code></code><code></code><code>-1</code> |- | <code>17</code> || <code></code><code></code><code>32</code> |- | <code>18</code> || <code></code><code></code><code>67</code> |- | <code>19</code> || <code></code><code>104</code> |- | <code>20</code> || <code></code><code>143</code> |- | <code>21</code> || <code></code><code>184</code> |- | <code>22</code> || <code></code><code>227</code> |- | <code>23</code> || <code></code><code>272</code> |- | <code>24</code> || <code></code><code>319</code> |- | <code>25</code> || <code></code><code>368</code> |- | <code>26</code> || <code></code><code>419</code> |} ==Law of addition== ===Factors of integer N=== Several modern methods for determining the factors of a given integer attempt to create two congruent squares modulo integer <math>N.</math> <math>x^2 \equiv y^2 \pmod{N}</math> This means that the difference between the two squares is exactly divisible by <math>N</math>: <math>N\mid (x^2 - y^2).</math> Integer <math>N</math> always contains the factors <math>N,1,</math> called trivial factors. If <math>N</math> contains two non-trivial factors <math>p,q,</math> then: <math>\frac{(x+y)(x-y)}{p \cdot q}.</math> With a little luck <math>p\mid (x+y)</math> and <math>q\mid (x-y)</math> in which case: <math>p = \text{igcd}(x+y, N)</math> and <math>q = \text{igcd}(x-y, N)</math> where "<math>\text{igcd}</math>" is function "<math>\text{integer greatest common divisor.}</math>" ====A simple example:==== We will use quadratic congruences to calculate factors of <math>N = 4171</math> for <math>164 \ge x \ge 1.</math> =====Right hand side exact square===== One congruence produced an exact square for y: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 70 | 4900 | 729 |} :<math>4900 \equiv 729 \pmod{N}</math> :<math>70^2 \equiv 27^2 \pmod{N}</math> <math>p = \text{igcd}(70-27, 4171)</math> <math>= \text{igcd}(43, 4171)</math> <math>= 43.</math> <math>q = \text{igcd}(70+27, 4171)</math> <math>= \text{igcd}(97, 4171)</math> <math>= 97.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> <math></math> <math></math> <math></math> <math></math> <math></math> <math></math> <math></math> <math></math> =====Right hand side negative===== Table below contains a sample of values of <math>x</math> that produce negative <math>y:</math> {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 7 | 49 | -4122 |- | 8 | 64 | -4107 ** |- | 9 | 81 | -4090 |- | 10 | 100 | -4071 |- | 11 | 121 | -4050 !! |- | 12 | 144 | -4027 |- | 60 | 3600 | -571 |- | 61 | 3721 | -450 <math>\ \ </math>!! |- | 62 | 3844 | -327 |- | 63 | 3969 | -202 |- | 64 | 4096 | -75 <math>\ \ \ \ </math>** |- | 65 | 4225 | 54 |} ======Non-trivial result 1====== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 8 | 64 | -4107 ** |- | 64 | 4096 | -75 <math>\ \ \ \ </math>** |} :<math>64 \equiv -4107 \pmod{N}</math> :<math>4096 \equiv -75 \pmod{N}</math> :<math>64\cdot 4096 \equiv -4107\cdot (-75) \pmod{N}</math> :<math>262144 \equiv 308025 \pmod{N}</math> :<math>512^2 \equiv 555^2 \pmod{4171}</math> <math>p = \text{igcd}(555-512, 4171)</math> <math>= \text{igcd}(43, 4171)</math> <math>= 43.</math> <math>q = \text{igcd}(555+512, 4171)</math> <math>= \text{igcd}(1067, 4171)</math> <math>= 97.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> ======Non-trivial result 2====== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 11 | 121 | -4050 !! |- | 61 | 3721 | -450 <math>\ \ </math>!! |} :<math>121 \equiv -4050 \pmod{N}</math> :<math>3721 \equiv -450 \pmod{N}</math> :<math>121\cdot 3721 \equiv -4050 \cdot (-450) \pmod{N}</math> :<math>450241 \equiv 1822500 \pmod{N}</math> :<math>671^2 \equiv 1350^2 \pmod{4171}</math> <math>p = \text{igcd}(1350-671, 4171)</math> <math>= \text{igcd}(679, 4171)</math> <math>= 97.</math> <math>q = \text{igcd}(1350+671, 4171)</math> <math>= \text{igcd}(2021, 4171)</math> <math>= 43.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> =====With 3 congruences===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 56 | 3136 | -1035 |- | 59 | 3481 | -690 |- | 145 | 21025 | 16854 |} :<math>3136 \equiv -1035 \pmod{N}</math> :<math>3481 \equiv -690 \pmod{N}</math> :<math>21025 \equiv 16854 \pmod{N}</math> :<math>3136\cdot 3481 \cdot 21025 \equiv -1035 \cdot -690 \cdot 16854 \pmod{N}</math> :<math>229517646400 \equiv 12036284100 \pmod{N}</math> :<math>479080^2 \equiv 109710^2 \pmod{4171}</math> <math>p=\text{igcd}(479080-109710,4171)</math> <math>= 43.</math> <math>q = \text{igcd}(479080+109710, 4171)</math> <math>= 97.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> <math></math> <math></math> <math></math> <math></math> <math></math> <math></math> ======Trivial result====== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 89 | 7921 | 3750 **!! |- | 145 | 21025 | 16854 <math>\ </math>!! |} :<math>7921 \equiv 3750 \pmod{N}</math> :<math>21025 \equiv 16854 \pmod{N}</math> :<math>7921\cdot 21025 \equiv 3750 \cdot 16854 \pmod{N}</math> :<math>166539025 \equiv 63202500 \pmod{N}</math> :<math>12905^2 \equiv 7950^2 \pmod{4171}</math> <math>p = \text{igcd}(12905-7950, 4171)</math> <math>= \text{igcd}(4955, 4171)</math> <math>= 1.</math> <math>q = \text{igcd}(12905+7950, 4171)</math> <math>= \text{igcd}(20855, 4171)</math> <math>= 4171.</math> This congruence produced the trivial factors of <math>4171.</math> <syntaxhighlight lang=python> # python code: </syntaxhighlight> ===Adding 2 congruences=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N}, </math> and <math>C \equiv D \pmod{N}, </math> then: <math>A+C \equiv B+D \pmod{N}.</math> Proof: <math>A-B = K_1\cdot N</math>, therefore <math>A = B + K_1\cdot N</math> and <math>C = D + K_2\cdot N</math> <math>(A+C) - (B+D) = B + K_1\cdot N + D + K_2\cdot N - B - D = N(K_1 + K_2)</math> which is exactly divisible by N. {{RoundBoxBottom}} ===Quadratic Congruences=== A quadratic congruence is a congruence that contains at least one exact square, for example: <math>x^2 \equiv y \pmod{N}</math> or <math>x^2 \equiv y^2 \pmod{N}.</math> Initially, let us consider the congruence: <math>x^2 \equiv y \pmod{N}.</math> If <math>y = x^2 - N,</math> then: <math>x^2 \equiv y \pmod{N}.</math> Proof: <math>x^2 - y = x^2 - (x^2 - N) = N</math> which is exactly divisible by <math>N.</math> Consider an example with real numbers. Let <math>N = 257</math> and <math>26 \ge x \ge 6.</math> <syntaxhighlight> N = 257 x | x^2 - N ----|-------- 6 | -221 7 | -208 8 | -193 9 | -176 10 | -157 11 | -136 12 | -113 13 | -88 14 | -61 15 | -32 16 | -1 17 | 32 18 | 67 19 | 104 20 | 143 21 | 184 22 | 227 23 | 272 24 | 319 25 | 368 26 | 419 </syntaxhighlight> A cursory glance at the values of <math>x^2 - N</math> indicates that the value <math>x^2 - N</math> is never divisible by <math>5.</math> Proof: <math>N \equiv 2 \pmod{5}</math> therefore <math>N - 2 = k5</math> or <math>N = 5k + 2.</math> The table shows all possible values of <math>x\ %\ 5:</math> <syntaxhighlight> x | x^2 | y = x^2 - N ------ | --------------- | ----------------------------------------------- 5p + 0 | 25pp | 25pp - (5k+2) = 25pp - 5k - 2 5p + 1 | 25pp + 10p + 1 | 25pp + 10p + 1 - (5k+2) = 25pp + 10p - 5k - 1 5p + 2 | 25pp + 20p + 4 | 25pp + 20p + 4 - (5k+2) = 25pp + 20p - 5k + 2 5p + 3 | 25pp + 30p + 9 | 25pp + 30p + 9 - (5k+2) = 25pp + 30p - 5k + 7 5p + 4 | 25pp + 40p + 16 | 25pp + 40p + 16 - (5k+2) = 25pp + 40p - 5k + 14 </syntaxhighlight> As you can see, the value <math>y = x^2 - N</math> is never exactly divisible by <math>5.</math> If you look closely, you will see also that it is never exactly divisible by <math>3.</math> Why is this? An interesting question that leads us to the topic of quadratic residues. ====Quadratic Residues==== Consider all the congruences for prime number <math>5:</math> <math>x^2 \equiv y \pmod{5}</math> for <math>5 > x \ge 0.</math> <syntaxhighlight> x | x^2 | (x^2) % 5 ---|---------|----------- 0 | 0 | 0 1 | 1 | 1 2 | 4 | 4 3 | 9 | 4 4 | 16 | 1 </syntaxhighlight> Quadratic residues of <math>5</math> are <math>0,1,4.</math> Values <math>2,3</math> are not quadratic residues of <math>5.</math> These values are quadratic non-residues. To calculate the quadratic residues of a small prime <math>p:</math> <syntaxhighlight lang=python> # python code: def quadResidues(p) : L1 = [] for v in range (p>>1, -1, -1) : L1 += [(v*v) % p] return L1 print (quadResidues(11)) </syntaxhighlight> <syntaxhighlight> [3, 5, 9, 4, 1, 0] </syntaxhighlight> Quadratic residues of <math>11</math> are <math>0,1,3,4,5,9.</math> The method presented here answers the question, "What are the quadratic residues of p?" If <math>p</math> is a very large prime, the question is often, "Is r a quadratic residue of p?" The answer is found in advanced number theory. Let us return to quadratic residues mod <math>N = 257.</math> <math>N\ %\ 5 = 2,</math> therefore <math>N</math> is not a quadratic residue of <math>5.</math> This is why <math>x^2 - N</math> is never divisible by <math>5</math> exactly. <math>N\ %\ 11 = 4,</math> therefore <math>N</math> is a quadratic residue of <math>11</math> and a value of <math>x</math> that satisfies the congruence <math>x^2 \equiv 4 \pmod{257}</math> has form <math>11p \pm 2.</math> From the table above: <syntaxhighlight> N = 257 x | x^2 - N ----|-------- 9 | -176 13 | -88 20 | 143 24 | 319 </syntaxhighlight> These <math>4</math> values of <math>x^2 - N</math> are exactly divisible by <math>11.</math> <math>x = 9</math> is <math>11\cdot 1 - 2.</math> <math>x = 13</math> is <math>11\cdot 1 + 2.</math> <math>x = 20</math> is <math>11\cdot 2 - 2.</math> <math>x = 24</math> is <math>11\cdot 2 + 2.</math> =====Products===== This section uses prime number <math>41</math> as an example. Using <code>quadResidues(p)</code> quadratic residues of <math>41</math> are: <syntaxhighlight> qr41 = [0, 1, 2, 4, 5, 8, 9, 10, 16, 18, 20, 21, 23, 25, 31, 32, 33, 36, 37, 39, 40] </syntaxhighlight> Quadratic non-residues of <math>41</math> are: <syntaxhighlight> qnr41 = [3, 6, 7, 11, 12, 13, 14, 15, 17, 19, 22, 24, 26, 27, 28, 29, 30, 34, 35, 38] </syntaxhighlight> ======of 2 residues====== A simple test to verify that the product of 2 residues is a residue: <syntaxhighlight lang=python> # Python code. for index1 in range (0, len(qr41)) : v1 = qr41[index1] for index2 in range (index1, len(qr41)) : v2 = qr41[index2] residue = (v1*v2) % 41 if residue not in qr41 : print ('residue',residue,'not quadratic.') </syntaxhighlight> This test shows that, at least for prime number <math>41,</math> the product of 2 residues is a residue. Advanced math proves that this is true for all primes. ======of 2 non-residues====== A simple test to verify that the product of 2 non-residues is a residue: <syntaxhighlight lang=python> # Python code. for index1 in range (0, len(qnr41)) : v1 = qnr41[index1] for index2 in range (index1, len(qnr41)) : v2 = qnr41[index2] residue = (v1*v2) % 41 if residue not in qr41 : print ('residue',residue,'not quadratic.') </syntaxhighlight> This test shows that, at least for prime number <math>41,</math> the product of 2 non-residues is a residue. Advanced math proves that this is true for all primes. ======of residue and non-residue====== A simple test to verify that the product of residue and non-residue is non-residue: <syntaxhighlight lang=python> # Python code. for index1 in range (1, len(qr41)) : v1 = qr41[index1] for index2 in range (0, len(qnr41)) : v2 = qnr41[index2] residue = (v1*v2) % 41 if residue not in qnr41 : print ('residue',residue,'quadratic.') </syntaxhighlight> This test shows that, at least for prime number <math>41,</math> the product of residue and non-residue is non-residue. Advanced math proves that this is true for all primes. {{RoundBoxTop|theme=2}} Some authors may consider <math>0</math> as not a legitimate residue. <math>0</math> is not included as a residue in the test above. {{RoundBoxBottom}} {{RoundBoxTop|theme=2}} <syntaxhighlight lang=python> </syntaxhighlight> <syntaxhighlight> </syntaxhighlight> {{RoundBoxBottom}} <math></math> <math></math> <math></math> ===Examples=== {{RoundBoxTop|theme=5}} <math></math> <math></math> <math></math> <math></math> <math>39x^2 + 64y^2 - 2496 = 0</math> <math>64x^2 + 39y^2 - 2496 = 0</math> <math></math> <math></math> <math></math> ====Techniques==== {{RoundBoxTop|theme=4}} =====For speed===== {{RoundBoxTop|theme=7}} ======Many comparisons====== {{RoundBoxTop|theme=8}} If your code contains many numerical comparisons, it may be tempting to put: <math></math> <math></math> <math></math> <math></math> <syntaxhighlight lang=python> # python code. if a == b == c == d == e == f == g == h == 0 : pass </syntaxhighlight> If all values <code>a,b,c,d,e,f,g,h</code> are equal and non-zero, processing the above statement takes time. For greater speed, put <math>0</math> and the value most likely to be non-zero at beginning of comparison: <syntaxhighlight lang=python> # python code. if 0 == f == a == b == c == d == e == g == h : pass </syntaxhighlight> <math></math> <math></math> <math></math> <math></math> <math></math> {{RoundBoxBottom}} ======Divide by 2====== {{RoundBoxTop|theme=8}} <math></math> <math></math> <math></math> <math></math> Division by 2 seems simple enough: <syntaxhighlight lang=python> # python code. a = b / 2 </syntaxhighlight> Divisions are time consuming. If b is a large Decimal number, the following code is faster: <syntaxhighlight lang=python> # python code. a = D('0.5') * b </syntaxhighlight> If b is <code>type int,</code> right shift is faster than multiplication by <code>0.5:</code> <syntaxhighlight lang=python> # python code. a = b >> 1 </syntaxhighlight> Also, right shift preserves precision of <code>type int:</code> <syntaxhighlight lang=python> # python code. >>> b = 12345678901234567890123456789 >>> a = b/2 ; a 6.172839450617284e+27 >>> a = b >> 1 ; a 6172839450617283945061728394 </syntaxhighlight> {{RoundBoxTop|theme=8}} To preserve rightmost bit: <syntaxhighlight lang=python> # python code. >>> b = 12345678901234567890123456789 >>> rightbit = b & 1 ; rightbit 1 >>> b >>= 1 ; b 6172839450617283945061728394 </syntaxhighlight> <math></math> <math></math> <math></math> <math></math> <math></math> {{RoundBoxBottom}} {{RoundBoxBottom}} {{RoundBoxBottom}} =====For clarity===== {{RoundBoxTop|theme=7}} <math></math> <math></math> <math></math> <math></math> <syntaxhighlight lang=python> # python code. </syntaxhighlight> <math></math> <math></math> {{RoundBoxBottom}} <math></math> <math></math> <math></math> <math></math> <syntaxhighlight lang=python> # python code. </syntaxhighlight> <math></math> <math></math> {{RoundBoxBottom}} {{RoundBoxBottom}} ===tables=== {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <math>\ \ </math><code>65</code>||<math>\ \ </math><code>4225</code>||<math>\ \ \ \ \ \ </math><code>54</code><math>\ \ </math><code>**</code><math>\ \ \ \ </math> |- | <math>\ \ </math><code>66</code>||<math>\ \ </math><code>4356</code>||<math>\ \ \ \ </math><code>185</code><math>\ \ \ \ \ \ \ \ \ \ </math> |- | <math>\ \ </math><code>88</code>||<math>\ \ </math><code>7744</code>||<math>\ \ </math><code>3573</code><math>\ \ \ \ \ \ \ \ \ \ </math> |- | <math>\ \ </math><code>89</code>||<math>\ \ </math><code>7921</code>||<math>\ \ </math><code>3750</code><math>\ \ </math><code>**!!</code> |- | <math>\ \ </math><code>90</code>||<math>\ \ </math><code>8100</code>||<math>\ \ </math><code>3929</code><math>\ \ \ \ \ \ \ \ \ \ </math> |- | <code>144</code>||<code>20736</code>||<code>16565</code><math>\ \ \ \ \ \ \ \ \ \ </math> |- | <code>145</code>||<code>21025</code>||<code>16854</code><math>\ \ \ \ \ \ </math><code>!!</code> |- | <code>146</code>||<code>21316</code>||<code>17145</code><math>\ \ \ \ \ \ \ \ \ \ </math> |} {{RoundBoxTop|theme=1}} {| class="wikitable" |- ! || No equal roots !! 2 equal roots !! 3 equal roots !! 4 equal roots !! 2 pairs of equal roots |- | Cubic: 1(a), 2(a) | different | different | different | same | different |- | Quadratic: 1(b), 2(b) | different | different | same, 1root | null | same, 2roots |- | Linear: 1(c), 2(c) | different | same | null | null | null |} See [[Cubic_function#Function_as_product_of_linear_function_and_quadratic | Function_as_product_of_linear_function_and_quadratic]] above. To calculate all roots: <syntaxhighlight lang=python> # python code. a,b,c,d = 1,-3,-9,-5 # Associated quadratic: p = -1 A = a B = A*p + b C = B*p + c # Associated linear function: a1 = A b1 = a1*p + B print ('x3 =', -b1/a1) </syntaxhighlight> <syntaxhighlight> x3 = 5.0 </syntaxhighlight> Roots of cubic function <math>f(x) = x^3 - 3x^2 - 9x - 5</math> are <math>-1, -1, 5.</math> <syntaxhighlight lang=python> # python code. </syntaxhighlight> {{RoundBoxBottom}} =Testing= ======table1====== {|style="border-left:solid 3px blue;border-right:solid 3px blue;border-top:solid 3px blue;border-bottom:solid 3px blue;" align="center" | Hello As <math>abs(x)</math> increases, the value of <math>f(x)</math> is dominated by the term <math>-ax^3.</math> When <math>x</math> has a very large negative value, <math>f(x)</math> is always positive. When <math>x</math> has a very large negative value, <math>f(x)</math> is always positive. When <math>x</math> has a very large negative value, <math>f(x)</math> is always positive. When <math>x</math> has a very large positive value, <math>f(x)</math> is always negative. <syntaxhighlight> 1.4142135623730950488016887242096980785696718753769480731766797379907324784621070388503875343276415727 3501384623091229702492483605585073721264412149709993583141322266592750559275579995050115278206057147 0109559971605970274534596862014728517418640889198609552329230484308714321450839762603627995251407989 </syntaxhighlight> |} {{RoundBoxTop|theme=2}} [[File:0410cubic01.png|thumb|400px|''' Graph of cubic function with coefficient a negative.''' </br> There is no absolute maximum or absolute minimum. ]] Coefficient <math>a</math> may be negative as shown in diagram. As <math>abs(x)</math> increases, the value of <math>f(x)</math> is dominated by the term <math>-ax^3.</math> When <math>x</math> has a very large negative value, <math>f(x)</math> is always positive. When <math>x</math> has a very large positive value, <math>f(x)</math> is always negative. Unless stated otherwise, any reference to "cubic function" on this page will assume coefficient <math>a</math> positive. {{RoundBoxBottom}} <math>x_{poi} = -1</math> <math></math> <math></math> <math></math> <math></math> =====Various planes in 3 dimensions===== {{RoundBoxTop|theme=2}} <gallery> File:0713x=4.png|<small>plane x=4.</small> File:0713y=3.png|<small>plane y=3.</small> File:0713z=-2.png|<small>plane z=-2.</small> </gallery> {{RoundBoxBottom}} <syntaxhighlight lang=python> </syntaxhighlight> <syntaxhighlight> </syntaxhighlight> <syntaxhighlight lang=python> </syntaxhighlight> <syntaxhighlight> </syntaxhighlight> <syntaxhighlight> 1.4142135623730950488016887242096980785696718753769480731766797379907324784621070388503875343276415727 3501384623091229702492483605585073721264412149709993583141322266592750559275579995050115278206057147 0109559971605970274534596862014728517418640889198609552329230484308714321450839762603627995251407989 6872533965463318088296406206152583523950547457502877599617298355752203375318570113543746034084988471 6038689997069900481503054402779031645424782306849293691862158057846311159666871301301561856898723723 5288509264861249497715421833420428568606014682472077143585487415565706967765372022648544701585880162 0758474922657226002085584466521458398893944370926591800311388246468157082630100594858704003186480342 1948972782906410450726368813137398552561173220402450912277002269411275736272804957381089675040183698 6836845072579936472906076299694138047565482372899718032680247442062926912485905218100445984215059112 0249441341728531478105803603371077309182869314710171111683916581726889419758716582152128229518488472 </syntaxhighlight> <math>\theta_1</math> {{RoundBoxTop|theme=2}} [[File:0422xx_x_2.png|thumb|400px|''' Figure 1: Diagram illustrating relationship between <math>f(x) = x^2 - x - 2</math> and <math>f'(x) = 2x - 1.</math>''' </br> ]] {{RoundBoxBottom}} <math>O\ (0,0,0)</math> <math>M\ (A_1,B_1,C_1)</math> <math>N\ (A_2,B_2,C_2)</math> <math>\theta</math> <math>\ \ \ \ \ \ \ \ </math> :<math>\begin{align} (6) - (7),\ 4Apq + 2Bq =&\ 0\\ 2Ap + B =&\ 0\\ 2Ap =&\ - B\\ \\ p =&\ \frac{-B}{2A}\ \dots\ (8) \end{align}</math> <math>\ \ \ \ \ \ \ \ </math> :<math>\begin{align} 1.&4141475869yugh\\ &2645er3423231sgdtrf\\ &dhcgfyrt45erwesd \end{align}</math> <math>\ \ \ \ \ \ \ \ </math> :<math> 4\sin 18^\circ = \sqrt{2(3 - \sqrt 5)} = \sqrt 5 - 1 </math> ====Introduction to floats==== {{RoundBoxTop|theme=5}} Although integers are great for many situations, they have a serious limitation, integers are [[Wikipedia:Natural number|whole numbers]]. This means that they do not include all [[Wikipedia:Real number|real numbers]]. A ''real number'' is a value that represents a quantity along a continuous line<ref>[[Wikipedia:Real number]]</ref>, which means that it can have fractions in decimal forms. <code>4.5</code>, <code>1.25</code>, and <code>0.75</code> are all real numbers. In computer science, real numbers are represented as floats. To test if a number is float, we can use the <code>isinstance</code> built-in function. <syntaxhighlight lang=python> >>> isinstance(4.5, float) True >>> isinstance(1.25, float) True >>> isinstance(0.75, float) True >>> isinstance(3.14159, float) True >>> isinstance(2.71828, float) True >>> isinstance(1.0, float) True >>> isinstance(271828, float) False >>> isinstance(0, float) False >>> isinstance(0.0, float) True </syntaxhighlight> As a general rule of thumb, floats have a ''[[Wikipedia:Decimal mark|decimal point]]'' and integers do not have a ''decimal point''. So even though <code>4</code> and <code>4.0</code> are the same number, <code>4</code> is an integer while <code>4.0</code> is a float. The basic arithmetic operations used for integers will also work for floats. (Bitwise operators will not work with floats.) <syntaxhighlight lang=python> >>> 4.0 + 2.0 6.0 >>> -1.0 + 4.5 3.5 >>> 1.75 - 1.5 0.25 >>> 4.13 - 1.1 3.03 >>> 4.5 // 1.0 4.0 >>> 4.5 / 1.0 4.5 >>> 4.5 % 1.0 0.5 >>> 7.75 * 0.25 1.9375 >>> 0.5 * 0.5 0.25 >>> 1.5 ** 2.0 2.25 </syntaxhighlight> {{RoundBoxBottom}} qis6rb4azom8be51q1esgfpcxuhou0j 0 224431 2413993 2411869 2022-08-12T17:28:11Z Ncharamut 2824970 /* Format */ updating format section wikitext text/x-wiki <noinclude>{{Helping Give Away Psychological Science Banner}}</noinclude> <!-- {{Helping Give Away Psychological Science Banner}} --> {{Wikipedia2|Society of Clinical Child and Adolescent Psychology}} This is the page for the '''Journal of Clinical Child and Adolescent Psychology's (JCCAP) Future Directions Forum (FDF)'''. It is held annually in June. Starting in 2018, ''The Forum'' will be held in Washington, DC, on the top floor of the American Psychological Association’s home office (www.spireeventsdc.com). Specifically, the ''JCCAP'' ''Future Directions Forum'' gives early-career scientists the tools to learn about emerging trends in child and adolescent mental health (CAMH), and succeed as academics within the “new frontiers” of interdisciplinary team science approaches to research. ''The'' ''Forum'' typically follows the format of 3-4 addresses on future directions topics as well as several workshops designed to help early-career scientists build their toolkit to be successful. Additionally, ''The Forum'' offers other programming such as grant consults, pocket labs, poster presentations, and the ''Future Directions Launch Award''. The pages below will give a breakdown of the topics discussed during each year's Forum as well as provide YouTube links to recorded workshops and addresses. == FDF Conference Coverage Pages == {| style="border-spacing: 2px; border: 1px solid darkgray;" ! style="width: 140px;" | [[JCCAP FDF/2017|'''<u><big>2017 JCCAP FDF</big></u>''']] ! style="width: 150px;" | [[JCCAP FDF/2018|'''<u><big>2018 JCCAP FDF</big></u>''']] ! style="width: 140px;" | [[JCCAP FDF/2019|'''<u><big>2019 JCCAP FDF</big></u>''']] ! style="width: 140px;" | [[JCCAP FDF/2020|'''<u><big>2020 JCCAP FDF</big></u>''']] ![[JCCAP FDF/2021|'''<big><u>2021 JCCAP FDF</u></big>''']] ! style="width: 140px;" | [[JCCAP FDF/2022|'''<u><big>2022 JCCAP FDF</big></u>''']] |} == What is special about this conference? == The field of child and adolescent mental health (CAMH) increasingly leverages knowledge from multiple disciplines to understand, assess, prevent, and treat the mental health concerns of children and adolescents. As a field, CAMH thrives when its constituent disciplines—Psychology, Psychiatry, Pediatrics, Public Health, Public Policy, Social Work, Education, Nursing, and Neuroscience, among others—build bridges to work with one another in an effort to improve the mental health of children and adolescents worldwide. However, these bridges do not build themselves. As a leading journal in CAMH, the ''Journal of Clinical Child and Adolescent Psychology'' (''JCCAP'') is in a unique position to leverage its status in the field to build bridges among CAMH disciplines. In fact, ''JCCAP'' publishes content with a large, interdisciplinary outreach. Regularly invited articles (i.e., ''Future Directions'') seek to unite affiliated disciplines in CAMH, in that they focus on topics of relevance to the diverse disciplines that comprise CAMH. In an effort to further strengthen these connections, 2017 marked the launch of the ''JCCAP'' ''Future Directions Forum''. This annual event showcases interdisciplinary work in CAMH, provides professional development training to early career scientists in CAMH, and raises public awareness of the “best and brightest” of this scientists-in-training. Specifically, the ''JCCAP'' ''Future Directions Forum'' gives early-career scientists the tools to learn about emerging trends in CAMH, and succeed as academics within the “new frontiers” of interdisciplinary team science approaches to research. The ''JCCAP'' ''Future Directions Forum'' achieves these goals in three ways: # Through invited addresses and panel discussions focused on the content of ''Future Directions'' articles, showcase emerging areas of interdisciplinary work in the field of CAMH # Through workshops and online resources, provide professional development training to all early career scientists who attend ''The'' ''Forum'' # Through research presentations, early career awards, and social media outreach raise international awareness of CAMH’s most promising early career scientists == Format == In previous years ''The Forum'' was held over the course of 2 days; however, since 2019, the format has changed to 3 days. === Day 1: Professional Development Training === ''The Forum'' includes an opening day completely dedicated to professional development training. ''The Forum'' registration fee includes a “professional development workshop day” consisting of interactive sessions and panel discussions. Specifically, on Day 1, attendees receive professional development training that consists of live, interactive workshops on such topics as scientific writing style and productivity, peer review, and preparing training grant applications. Day 1 also includes panel discussions on issues of grant funding. Panelists consist of program officers from federal funding agencies with funding priorities that intersect with topics covered at the forum, such as the National Institutes of Health, National Science Foundation, and Institute of Education Sciences. Every year, new attendees of the forum receive exposure to the interactive workshops described previously, as well as attend panel discussions on grant funding. However, returning attendees have the opportunity to continue their education via online resources, and more intensive, personalized on-site sessions at the forum. Using this graduated scaling of professional development, the ''JCCAP Future Directions Forum'' seeks to build lasting relationships with its early career attendees, and ensure a growing and sustained attendance at the forum from year-to-year. === Day 2: Showcasing ''JCCAP''’s ''Future Directions'' Content === '''''Addresses:''''' At each forum, leaders in the field who recently published ''Future Directions'' articles at ''JCCAP'' give formal addresses on the “next steps” of scientific research in their area of expertise. We hold these addresses on Day 2 of the forum. These addresses are based on the content of ''Future Directions'' articles written by the speakers. '''''Panel Discussions''':'' Following each ''Future Directions Address'', panel discussions serve as “brainstorming sessions” for new science that builds on research covered in the address. Attendees “break out” into one of several discussions moderated by faculty with expertise in the ''Future Directions'' content. These interactive discussions are organized by areas linked to the ''Future Directions Addresses'' (e.g., neuroscience, treatment, cross-cultural research). In advance of the forum, panel leaders identify publicly available resources for new research (e.g., public datasets, funding announcements). In turn, these panel discussions yield “deliverables” in that attendees develop both specific research aims, and concrete strategies for securing data or funding to test the aims. This format sparks “omnidirectional” discussions among panel leaders and attendees about new science along topics linked to the forum addresses. At our panel discussions, forum attendees make the future of science happen! === Days 1-2: Early Career Scientists: Celebrating Promising Research in Mental Health === '''''Poster Session Socials:''''' Before the forum, early career scientists submit abstracts of their research. At the forum, they make poster presentations of this research during catered social events. In advance of the forum, presenters are prompted via email to upload a single-slide ''Powerpoint'' file of their presentation. At the forum, we integrate these files into our own digital system to have them ready to present during the poster session socials. Thus, all poster presentations are digitally presented, saving presenters both time and money. Poster session socials take place during the evenings of the forum. Further, these events provide early career scientists with opportunities for “one-on-one” time with scientists who gave addresses during the forum. '''''Future Directions Launch Award:''''' Before the forum, a committee of internationally recognized scientists selects several promising early career scientists who are presenting their research at the forum to receive a widely-publicized award: the ''Future Directions Launch Award''. The award recognizes early career scientists conducting research in the ''Future Directions Address'' topics covered that year (i.e., one awardee for each ''Future Directions Address'' topic). At an award ceremony held during the forum, awardees give TED Talk-style presentations about their work. We stream these presentations live, store them, and link them to a major media dissemination platform (e.g., YouTube). The ''Future Directions Launch Award'' serves as a capstone to the academic training of its recipients—a signal to the field and larger public that they are ready to enter academia and begin independent research careers. == Benefits to society == Over the last 50 years, the field of CAMH has made enormous contributions to society. Scientists in the field produced accurate, reliable diagnostic tools, allowing clinicians to identify children and adolescents in need of care. CAMH scientists developed effective, evidence-based treatments, allowing children and adolescents to work through their challenges and learn coping skills. Now, the field needs a new generation of scientists to solve the field’s most pressing problems. For instance, although some children and adolescents benefit from receiving mental health treatments, roughly 1/3 to 1/2 of all those treated receive little-to-no benefits. Why do these problems persist? A key issue involves poor understanding of the factors that cause children and adolescents to develop mental health concerns. As a result, the field has a lot to learn about why mental health treatments “work,” and for whom these treatments work best. The next generation of scientists in the field need to solve these problems. However, these problems require the collective action of all disciplines affiliated with CAMH. The CAMH field needs the next generation of scientists in CAMH to learn to build bridges among its constituent disciplines. Further, beyond the “book smarts” they acquire in the classroom, early career scientists need the “street smarts” to succeed in academia. Few of them take a class in writing great journal articles, communicating ideas during a job interview, or writing successful grant proposals. If society’s early career scientists do not “make it,” then progress in CAMH stalls, and society would settle for mental health treatments that help only a fraction of those who receive them. The ''JCCAP'' ''Future Directions Forum'' meets these needs by providing early career scientists exposure to interdisciplinary research in CAMH, and the fuel to become great academics! == Location  == The ''JCCAP'' ''Future Directions Forum'' is held annually in June. Starting in 2018, the Forum will be held in Washington, DC, on the top floor of the [https://apabuildings.buildingengines.com/geofire/BDPW?conid=1613209322&id_site=0&id_client_site_rel=0 American Psychological Association’s home office]. 2020 and 2021 Forums were held online due to [[COVID-19]]. The 2022 Forum will be held in a different format as a webinar series throughout the summer and fall of 2022. For more information on this year's Forum, please visit the website [https://jccapfuturedirectionsforum.weebly.com/ here]. == Further information == Each year's Forum has a page that lists the address and workshops with links to view the recording for those we were able to record. Each year's page also has the Launch Award winners with links to view their remarks. Thanks to Dr. De Los Reyes for the vision and leadership to build the conference; to SCCAP, the American Psychological Association, and the University of Maryland for the support and resources to make the inaugural conference possible, and to the team of research assistants, students, and colleagues that did a wonderful job making the FDF such a success! jtitfkqdg7vw3pwn4npxtbqldvpi93l 2413994 2413993 2022-08-12T17:33:35Z Ncharamut 2824970 /* Format */ updating format section wikitext text/x-wiki <noinclude>{{Helping Give Away Psychological Science Banner}}</noinclude> <!-- {{Helping Give Away Psychological Science Banner}} --> {{Wikipedia2|Society of Clinical Child and Adolescent Psychology}} This is the page for the '''Journal of Clinical Child and Adolescent Psychology's (JCCAP) Future Directions Forum (FDF)'''. It is held annually in June. Starting in 2018, ''The Forum'' will be held in Washington, DC, on the top floor of the American Psychological Association’s home office (www.spireeventsdc.com). Specifically, the ''JCCAP'' ''Future Directions Forum'' gives early-career scientists the tools to learn about emerging trends in child and adolescent mental health (CAMH), and succeed as academics within the “new frontiers” of interdisciplinary team science approaches to research. ''The'' ''Forum'' typically follows the format of 3-4 addresses on future directions topics as well as several workshops designed to help early-career scientists build their toolkit to be successful. Additionally, ''The Forum'' offers other programming such as grant consults, pocket labs, poster presentations, and the ''Future Directions Launch Award''. The pages below will give a breakdown of the topics discussed during each year's Forum as well as provide YouTube links to recorded workshops and addresses. == FDF Conference Coverage Pages == {| style="border-spacing: 2px; border: 1px solid darkgray;" ! style="width: 140px;" | [[JCCAP FDF/2017|'''<u><big>2017 JCCAP FDF</big></u>''']] ! style="width: 150px;" | [[JCCAP FDF/2018|'''<u><big>2018 JCCAP FDF</big></u>''']] ! style="width: 140px;" | [[JCCAP FDF/2019|'''<u><big>2019 JCCAP FDF</big></u>''']] ! style="width: 140px;" | [[JCCAP FDF/2020|'''<u><big>2020 JCCAP FDF</big></u>''']] ![[JCCAP FDF/2021|'''<big><u>2021 JCCAP FDF</u></big>''']] ! style="width: 140px;" | [[JCCAP FDF/2022|'''<u><big>2022 JCCAP FDF</big></u>''']] |} == What is special about this conference? == The field of child and adolescent mental health (CAMH) increasingly leverages knowledge from multiple disciplines to understand, assess, prevent, and treat the mental health concerns of children and adolescents. As a field, CAMH thrives when its constituent disciplines—Psychology, Psychiatry, Pediatrics, Public Health, Public Policy, Social Work, Education, Nursing, and Neuroscience, among others—build bridges to work with one another in an effort to improve the mental health of children and adolescents worldwide. However, these bridges do not build themselves. As a leading journal in CAMH, the ''Journal of Clinical Child and Adolescent Psychology'' (''JCCAP'') is in a unique position to leverage its status in the field to build bridges among CAMH disciplines. In fact, ''JCCAP'' publishes content with a large, interdisciplinary outreach. Regularly invited articles (i.e., ''Future Directions'') seek to unite affiliated disciplines in CAMH, in that they focus on topics of relevance to the diverse disciplines that comprise CAMH. In an effort to further strengthen these connections, 2017 marked the launch of the ''JCCAP'' ''Future Directions Forum''. This annual event showcases interdisciplinary work in CAMH, provides professional development training to early career scientists in CAMH, and raises public awareness of the “best and brightest” of this scientists-in-training. Specifically, the ''JCCAP'' ''Future Directions Forum'' gives early-career scientists the tools to learn about emerging trends in CAMH, and succeed as academics within the “new frontiers” of interdisciplinary team science approaches to research. The ''JCCAP'' ''Future Directions Forum'' achieves these goals in three ways: # Through invited addresses and panel discussions focused on the content of ''Future Directions'' articles, showcase emerging areas of interdisciplinary work in the field of CAMH # Through workshops and online resources, provide professional development training to all early career scientists who attend ''The'' ''Forum'' # Through research presentations, early career awards, and social media outreach raise international awareness of CAMH’s most promising early career scientists == Format == In previous years ''The Forum'' was held over the course of 2 days; however, since 2021, the format has changed to 3 days. Both formats (2 days and 3 days) are described below. The exception to this is that the 2022 forum was held in the format of a webinar series with several pieces of programming each month from July 2022 to December 2022. === 2 Day Format (2017-2020) === ==== Day 1: Professional Development Training ==== ''The Forum'' includes an opening day completely dedicated to professional development training. ''The Forum'' registration fee includes a “professional development workshop day” consisting of interactive sessions and panel discussions. Specifically, on Day 1, attendees receive professional development training that consists of live, interactive workshops on such topics as scientific writing style and productivity, peer review, and preparing training grant applications. Day 1 also includes panel discussions on issues of grant funding. Panelists consist of program officers from federal funding agencies with funding priorities that intersect with topics covered at the forum, such as the National Institutes of Health, National Science Foundation, and Institute of Education Sciences. Every year, new attendees of the forum receive exposure to the interactive workshops described previously, as well as attend panel discussions on grant funding. However, returning attendees have the opportunity to continue their education via online resources, and more intensive, personalized on-site sessions at the forum. Using this graduated scaling of professional development, the ''JCCAP Future Directions Forum'' seeks to build lasting relationships with its early career attendees, and ensure a growing and sustained attendance at the forum from year-to-year. ==== Day 2: Showcasing ''JCCAP''’s ''Future Directions'' Content ==== '''''Addresses:''''' At each forum, leaders in the field who recently published ''Future Directions'' articles at ''JCCAP'' give formal addresses on the “next steps” of scientific research in their area of expertise. We hold these addresses on Day 2 of the forum. These addresses are based on the content of ''Future Directions'' articles written by the speakers. '''''Panel Discussions''':'' Following each ''Future Directions Address'', panel discussions serve as “brainstorming sessions” for new science that builds on research covered in the address. Attendees “break out” into one of several discussions moderated by faculty with expertise in the ''Future Directions'' content. These interactive discussions are organized by areas linked to the ''Future Directions Addresses'' (e.g., neuroscience, treatment, cross-cultural research). In advance of the forum, panel leaders identify publicly available resources for new research (e.g., public datasets, funding announcements). In turn, these panel discussions yield “deliverables” in that attendees develop both specific research aims, and concrete strategies for securing data or funding to test the aims. This format sparks “omnidirectional” discussions among panel leaders and attendees about new science along topics linked to the forum addresses. At our panel discussions, forum attendees make the future of science happen! ==== Days 1-2: Early Career Scientists: Celebrating Promising Research in Mental Health ==== '''''Poster Session Socials:''''' Before the forum, early career scientists submit abstracts of their research. At the forum, they make poster presentations of this research during catered social events. In advance of the forum, presenters are prompted via email to upload a single-slide ''Powerpoint'' file of their presentation. At the forum, we integrate these files into our own digital system to have them ready to present during the poster session socials. Thus, all poster presentations are digitally presented, saving presenters both time and money. Poster session socials take place during the evenings of the forum. Further, these events provide early career scientists with opportunities for “one-on-one” time with scientists who gave addresses during the forum. '''''Future Directions Launch Award:''''' Before the forum, a committee of internationally recognized scientists selects several promising early career scientists who are presenting their research at the forum to receive a widely-publicized award: the ''Future Directions Launch Award''. The award recognizes early career scientists conducting research in the ''Future Directions Address'' topics covered that year (i.e., one awardee for each ''Future Directions Address'' topic). At an award ceremony held during the forum, awardees give TED Talk-style presentations about their work. We stream these presentations live, store them, and link them to a major media dissemination platform (e.g., YouTube). The ''Future Directions Launch Award'' serves as a capstone to the academic training of its recipients—a signal to the field and larger public that they are ready to enter academia and begin independent research careers. === 3 Day Format === == Benefits to society == Over the last 50 years, the field of CAMH has made enormous contributions to society. Scientists in the field produced accurate, reliable diagnostic tools, allowing clinicians to identify children and adolescents in need of care. CAMH scientists developed effective, evidence-based treatments, allowing children and adolescents to work through their challenges and learn coping skills. Now, the field needs a new generation of scientists to solve the field’s most pressing problems. For instance, although some children and adolescents benefit from receiving mental health treatments, roughly 1/3 to 1/2 of all those treated receive little-to-no benefits. Why do these problems persist? A key issue involves poor understanding of the factors that cause children and adolescents to develop mental health concerns. As a result, the field has a lot to learn about why mental health treatments “work,” and for whom these treatments work best. The next generation of scientists in the field need to solve these problems. However, these problems require the collective action of all disciplines affiliated with CAMH. The CAMH field needs the next generation of scientists in CAMH to learn to build bridges among its constituent disciplines. Further, beyond the “book smarts” they acquire in the classroom, early career scientists need the “street smarts” to succeed in academia. Few of them take a class in writing great journal articles, communicating ideas during a job interview, or writing successful grant proposals. If society’s early career scientists do not “make it,” then progress in CAMH stalls, and society would settle for mental health treatments that help only a fraction of those who receive them. The ''JCCAP'' ''Future Directions Forum'' meets these needs by providing early career scientists exposure to interdisciplinary research in CAMH, and the fuel to become great academics! == Location  == The ''JCCAP'' ''Future Directions Forum'' is held annually in June. Starting in 2018, the Forum will be held in Washington, DC, on the top floor of the [https://apabuildings.buildingengines.com/geofire/BDPW?conid=1613209322&id_site=0&id_client_site_rel=0 American Psychological Association’s home office]. 2020 and 2021 Forums were held online due to [[COVID-19]]. The 2022 Forum will be held in a different format as a webinar series throughout the summer and fall of 2022. For more information on this year's Forum, please visit the website [https://jccapfuturedirectionsforum.weebly.com/ here]. == Further information == Each year's Forum has a page that lists the address and workshops with links to view the recording for those we were able to record. Each year's page also has the Launch Award winners with links to view their remarks. Thanks to Dr. De Los Reyes for the vision and leadership to build the conference; to SCCAP, the American Psychological Association, and the University of Maryland for the support and resources to make the inaugural conference possible, and to the team of research assistants, students, and colleagues that did a wonderful job making the FDF such a success! h201fb0cmo273a9hysy7tiba13ipsc1 2413995 2413994 2022-08-12T17:44:22Z Ncharamut 2824970 /* 3 Day Format */ added 3 day format wikitext text/x-wiki <noinclude>{{Helping Give Away Psychological Science Banner}}</noinclude> <!-- {{Helping Give Away Psychological Science Banner}} --> {{Wikipedia2|Society of Clinical Child and Adolescent Psychology}} This is the page for the '''Journal of Clinical Child and Adolescent Psychology's (JCCAP) Future Directions Forum (FDF)'''. It is held annually in June. Starting in 2018, ''The Forum'' will be held in Washington, DC, on the top floor of the American Psychological Association’s home office (www.spireeventsdc.com). Specifically, the ''JCCAP'' ''Future Directions Forum'' gives early-career scientists the tools to learn about emerging trends in child and adolescent mental health (CAMH), and succeed as academics within the “new frontiers” of interdisciplinary team science approaches to research. ''The'' ''Forum'' typically follows the format of 3-4 addresses on future directions topics as well as several workshops designed to help early-career scientists build their toolkit to be successful. Additionally, ''The Forum'' offers other programming such as grant consults, pocket labs, poster presentations, and the ''Future Directions Launch Award''. The pages below will give a breakdown of the topics discussed during each year's Forum as well as provide YouTube links to recorded workshops and addresses. == FDF Conference Coverage Pages == {| style="border-spacing: 2px; border: 1px solid darkgray;" ! style="width: 140px;" | [[JCCAP FDF/2017|'''<u><big>2017 JCCAP FDF</big></u>''']] ! style="width: 150px;" | [[JCCAP FDF/2018|'''<u><big>2018 JCCAP FDF</big></u>''']] ! style="width: 140px;" | [[JCCAP FDF/2019|'''<u><big>2019 JCCAP FDF</big></u>''']] ! style="width: 140px;" | [[JCCAP FDF/2020|'''<u><big>2020 JCCAP FDF</big></u>''']] ![[JCCAP FDF/2021|'''<big><u>2021 JCCAP FDF</u></big>''']] ! style="width: 140px;" | [[JCCAP FDF/2022|'''<u><big>2022 JCCAP FDF</big></u>''']] |} == What is special about this conference? == The field of child and adolescent mental health (CAMH) increasingly leverages knowledge from multiple disciplines to understand, assess, prevent, and treat the mental health concerns of children and adolescents. As a field, CAMH thrives when its constituent disciplines—Psychology, Psychiatry, Pediatrics, Public Health, Public Policy, Social Work, Education, Nursing, and Neuroscience, among others—build bridges to work with one another in an effort to improve the mental health of children and adolescents worldwide. However, these bridges do not build themselves. As a leading journal in CAMH, the ''Journal of Clinical Child and Adolescent Psychology'' (''JCCAP'') is in a unique position to leverage its status in the field to build bridges among CAMH disciplines. In fact, ''JCCAP'' publishes content with a large, interdisciplinary outreach. Regularly invited articles (i.e., ''Future Directions'') seek to unite affiliated disciplines in CAMH, in that they focus on topics of relevance to the diverse disciplines that comprise CAMH. In an effort to further strengthen these connections, 2017 marked the launch of the ''JCCAP'' ''Future Directions Forum''. This annual event showcases interdisciplinary work in CAMH, provides professional development training to early career scientists in CAMH, and raises public awareness of the “best and brightest” of this scientists-in-training. Specifically, the ''JCCAP'' ''Future Directions Forum'' gives early-career scientists the tools to learn about emerging trends in CAMH, and succeed as academics within the “new frontiers” of interdisciplinary team science approaches to research. The ''JCCAP'' ''Future Directions Forum'' achieves these goals in three ways: # Through invited addresses and panel discussions focused on the content of ''Future Directions'' articles, showcase emerging areas of interdisciplinary work in the field of CAMH # Through workshops and online resources, provide professional development training to all early career scientists who attend ''The'' ''Forum'' # Through research presentations, early career awards, and social media outreach raise international awareness of CAMH’s most promising early career scientists == Format == In previous years ''The Forum'' was held over the course of 2 days; however, since 2021, the format has changed to 3 days. Both formats (2 days and 3 days) are described below. The exception to this is that the 2022 forum was held in the format of a webinar series with several pieces of programming each month from July 2022 to December 2022. === 2 Day Format (2017-2020) === ==== Day 1: Professional Development Training ==== ''The Forum'' includes an opening day completely dedicated to professional development training. ''The Forum'' registration fee includes a “professional development workshop day” consisting of interactive sessions and panel discussions. Specifically, on Day 1, attendees receive professional development training that consists of live, interactive workshops on such topics as scientific writing style and productivity, peer review, and preparing training grant applications. Day 1 also includes panel discussions on issues of grant funding. Panelists consist of program officers from federal funding agencies with funding priorities that intersect with topics covered at the forum, such as the National Institutes of Health, National Science Foundation, and Institute of Education Sciences. Every year, new attendees of the forum receive exposure to the interactive workshops described previously, as well as attend panel discussions on grant funding. However, returning attendees have the opportunity to continue their education via online resources, and more intensive, personalized on-site sessions at the forum. Using this graduated scaling of professional development, the ''JCCAP Future Directions Forum'' seeks to build lasting relationships with its early career attendees, and ensure a growing and sustained attendance at the forum from year-to-year. ==== Day 2: Showcasing ''JCCAP''’s ''Future Directions'' Content ==== '''''Addresses:''''' At each forum, leaders in the field who recently published ''Future Directions'' articles at ''JCCAP'' give formal addresses on the “next steps” of scientific research in their area of expertise. We hold these addresses on Day 2 of the forum. These addresses are based on the content of ''Future Directions'' articles written by the speakers. '''''Panel Discussions''':'' Following each ''Future Directions Address'', panel discussions serve as “brainstorming sessions” for new science that builds on research covered in the address. Attendees “break out” into one of several discussions moderated by faculty with expertise in the ''Future Directions'' content. These interactive discussions are organized by areas linked to the ''Future Directions Addresses'' (e.g., neuroscience, treatment, cross-cultural research). In advance of the forum, panel leaders identify publicly available resources for new research (e.g., public datasets, funding announcements). In turn, these panel discussions yield “deliverables” in that attendees develop both specific research aims, and concrete strategies for securing data or funding to test the aims. This format sparks “omnidirectional” discussions among panel leaders and attendees about new science along topics linked to the forum addresses. At our panel discussions, forum attendees make the future of science happen! ==== Days 1-2: Early Career Scientists: Celebrating Promising Research in Mental Health ==== '''''Poster Session Socials:''''' Before the forum, early career scientists submit abstracts of their research. At the forum, they make poster presentations of this research during catered social events. In advance of the forum, presenters are prompted via email to upload a single-slide ''Powerpoint'' file of their presentation. At the forum, we integrate these files into our own digital system to have them ready to present during the poster session socials. Thus, all poster presentations are digitally presented, saving presenters both time and money. Poster session socials take place during the evenings of the forum. Further, these events provide early career scientists with opportunities for “one-on-one” time with scientists who gave addresses during the forum. '''''Future Directions Launch Award:''''' Before the forum, a committee of internationally recognized scientists selects several promising early career scientists who are presenting their research at the forum to receive a widely-publicized award: the ''Future Directions Launch Award''. The award recognizes early career scientists conducting research in the ''Future Directions Address'' topics covered that year (i.e., one awardee for each ''Future Directions Address'' topic). At an award ceremony held during the forum, awardees give TED Talk-style presentations about their work. We stream these presentations live, store them, and link them to a major media dissemination platform (e.g., YouTube). The ''Future Directions Launch Award'' serves as a capstone to the academic training of its recipients—a signal to the field and larger public that they are ready to enter academia and begin independent research careers. === 3 Day Format === ==== Day 1 ==== Days 1 begins with workshops and professional development. There are usually 2 tracks for workshops and attendees can pick which workshops they attend. There are 2 workshop sessions before concluding the day with the first ''Future Directions Address'' and discussion related to the address. ==== Day 2 ==== Day 2 begins with one set of workshops where attendees can pick which one they attend. Then, the day transitions to the ''Launch Award'' winners presentations and the second day concludes with the second ''Future Directions Address'' and discussion. ==== Day 3 ==== The final day of ''The Forum'' begins with another set of workshops where attendees can pick which one they attend. Next is the poster Q&A session where poster presenters are available to answer questions about their research. the day concludes with the final ''Future Directions Address'' and discussion. == Benefits to society == Over the last 50 years, the field of CAMH has made enormous contributions to society. Scientists in the field produced accurate, reliable diagnostic tools, allowing clinicians to identify children and adolescents in need of care. CAMH scientists developed effective, evidence-based treatments, allowing children and adolescents to work through their challenges and learn coping skills. Now, the field needs a new generation of scientists to solve the field’s most pressing problems. For instance, although some children and adolescents benefit from receiving mental health treatments, roughly 1/3 to 1/2 of all those treated receive little-to-no benefits. Why do these problems persist? A key issue involves poor understanding of the factors that cause children and adolescents to develop mental health concerns. As a result, the field has a lot to learn about why mental health treatments “work,” and for whom these treatments work best. The next generation of scientists in the field need to solve these problems. However, these problems require the collective action of all disciplines affiliated with CAMH. The CAMH field needs the next generation of scientists in CAMH to learn to build bridges among its constituent disciplines. Further, beyond the “book smarts” they acquire in the classroom, early career scientists need the “street smarts” to succeed in academia. Few of them take a class in writing great journal articles, communicating ideas during a job interview, or writing successful grant proposals. If society’s early career scientists do not “make it,” then progress in CAMH stalls, and society would settle for mental health treatments that help only a fraction of those who receive them. The ''JCCAP'' ''Future Directions Forum'' meets these needs by providing early career scientists exposure to interdisciplinary research in CAMH, and the fuel to become great academics! == Location  == The ''JCCAP'' ''Future Directions Forum'' is held annually in June. Starting in 2018, the Forum will be held in Washington, DC, on the top floor of the [https://apabuildings.buildingengines.com/geofire/BDPW?conid=1613209322&id_site=0&id_client_site_rel=0 American Psychological Association’s home office]. 2020 and 2021 Forums were held online due to [[COVID-19]]. The 2022 Forum will be held in a different format as a webinar series throughout the summer and fall of 2022. For more information on this year's Forum, please visit the website [https://jccapfuturedirectionsforum.weebly.com/ here]. == Further information == Each year's Forum has a page that lists the address and workshops with links to view the recording for those we were able to record. Each year's page also has the Launch Award winners with links to view their remarks. Thanks to Dr. De Los Reyes for the vision and leadership to build the conference; to SCCAP, the American Psychological Association, and the University of Maryland for the support and resources to make the inaugural conference possible, and to the team of research assistants, students, and colleagues that did a wonderful job making the FDF such a success! 903hww55akafbygv2kf9nj29c957wdw 0 232469 2414062 2413305 2022-08-13T09:30:04Z Young1lim 21186 /* ARM Assembly Programming (II) */ wikitext text/x-wiki == '''Background''' == '''Combinational and Sequential Circuits''' * [[Media:DD2.B.4..Adder.20131007.pdf |Adder]] * [[Media:DD3.A.1.LatchFF.20160308.pdf |Latches and Flipflops]] '''FSM''' * [[Media:DD3.A.3.FSM.20131030.pdf |FSM]] * [[Media:CArch.2.A.Bubble.20131021.pdf |FSM Example]] '''Tiny CPU Example''' * [[Media:CDsgn6.TinyCPU.2.A.ISA.20160511.pdf |Instruction Set]] * [[Media:CDsgn6.TinyCPU.2.B.DPath.20160502.pdf |Data Path]] * [[Media:CDsgn6.TinyCPU.2.C.CPath.20160427.pdf |Control Path]] * [[Media:CDsgn6.TinyCPU.2.D.Implement.20160513.pdf |FPGA Implementation]] </br> == '''Microprocessor Architecture''' == * ARM Architecture : - Programmer's Model ([[Media:ARM.1Arch.1A.Model.20180321.pdf |pdf]]) : - Pipelined Architecture ([[Media:ARM.1Arch.2A.Pipeline.20180419.pdf |pdf]]) * ARM Organization * ARM Cortex-M Processor Architecture * ARM Processor Cores </br> == '''Instruction Set Architecture''' == * ARM Instruction Set : - Overview ([[Media:ARM.2ISA.1A.Overview.20190611.pdf |pdf]]) : - Addressing Modes ([[Media:ARM.2ISA.2A.AddrMode.20191108.pdf |pdf]]) : - Multiple Transfer ([[Media:ARM.2ISA.3A.MTransfer.20190903.pdf |pdf]]) : - Assembler Format :: - Data Processing ([[Media:ARM.2ISA.4A.Proc.Format.20200204.pdf |pdf]]) :: - Data Transfer ([[Media:ARM.2ISA.4B.Trans.Format.20200205.pdf |pdf]]) :: - Coprocessor ([[Media:ARM.2ISA.4C.CoProc.Format.20191214.pdf |pdf]]) :: - Summary ([[Media:ARM.2ISA.4D.Summary.Format.20200205.pdf |pdf]]) : - Binary Encoding ([[Media:ARM.2ISA.5A.Encoding.201901105.pdf |pdf]]) * Thumb Instruction Set </br> == '''Assembly Programming''' == === ARM Assembly Programming (I) === * 1. Overview ([[Media:ARM.2ASM.1A.Overview.20200101.pdf |pdf]]) * 2. Example Programs ([[Media:ARM.2ASM.2A.Program.20200108.pdf |pdf]]) * 3. Addressing Modes ([[Media:ARM.2ASM.3A.Address.20200127.pdf |pdf]]) * 4. Data Transfer ([[Media:ARM.2ASM.4A.DTransfer.20200206.pdf |pdf]]) * 5. Data Processing ([[Media:ARM.2ASM.5A.DProcess.20200208.pdf |pdf]]) * 6. Control ([[Media:ARM.2ASM.6A.Control.20200215.pdf |pdf]]) * 7. Arrays ([[Media:ARM.2ASM.7A.Array.20200311.pdf |pdf]]) * 8. Data Structures ([[Media:ARM.2ASM.8A.DataStruct.20200718.pdf |pdf]]) * 9. Finite State Machines ([[Media:ARM.2ASM.9A.FSM.20200417.pdf |pdf]]) * 10. Functions ([[Media:ARM.2ASM.10A.Function.20210115.pdf |pdf]]) * 11. Parameter Passing ([[Media:ARM.2ASM.11A.Parameter.20210106.pdf |pdf]]) * 12. Stack Frames ([[Media:ARM.2ASM.12A.StackFrame.20210611.pdf |pdf]]) :: :: === ARM Assembly Programming (II) === :: * 1. Thumb instruction programming ([[Media:ARM.2ASM.Thumb.20210612.pdf |pdf]]) * 2. Exceptions ([[Media:ARM.2ASM.Exception.20220722.pdf |pdf]]) * 3. Exception Programming ([[Media:ARM.2ASM.ExceptionProg.20220311.pdf |pdf]]) * 4. Exception Handlers ([[Media:ARM.2ASM.ExceptionHandler.20220131.pdf |pdf]]) * 5. Interrupt Programming ([[Media:ARM.2ASM.InterruptProg.20211030.pdf |pdf]]) * 6. Interrupt Handlers ([[Media:ARM.2ASM.InterruptHandler.20211030.pdf |pdf]]) * 7. Vectored Interrupt Programming ([[Media:ARM.2ASM.VectorInt.20220810.pdf |pdf]]) </br> * ARM Assembly Exercises ([[Media:ESys.3.A.ARM-ASM-Exercise.20160608.pdf |A.pdf]], [[Media:ESys.3.B.Assembly.20160716.pdf |B.pdf]]) :: === ARM Assembly Programming (III) === * 1. Fixed point arithmetic (integer division) * 2. Floating point arithmetic * 3. Matrix multiply === ARM Linking === * arm link ([[Media:arm_link.20211208.pdf |pdf]]) </br> === ARM Microcontroller Programming === * 1. Input / Output * 2. Serial / Parallel Port Interfacing * 3. Analog I/O Interfacing * 4. Communication </br> == '''Memory Architecture''' == </br> === '''Memory Hierarchy''' === </br> === '''System and Peripheral Buses''' === </br> === '''Architectural Support''' === * High Level Languages * System Development * Operating Systems </br> == '''Peripheral Architecture''' == </br> === '''Vectored Interrupt Controller ''' === </br> === '''Timers ''' === * Timer / Counter ([[Media:ARM.4ASM.Timer.20220801.pdf |pdf]]) * Real Time Clock * Watchdog Timer </br> === '''Serial Bus''' === * '''UART''' : Universal Asynchronous Receiver/Transmitter ([[Media:ARM.4ASM.UART.20220809.pdf |pdf]]) * '''I2C''' : Inter-Integrated Circuit * '''SPI''' : Serial Peripheral Interface * '''USB''' : Universal Serial Bus Device Controller </br> === '''I/Os ''' === * General Purpose Input/Output ports (GPIO) * Pulse Width Modulator * Analog-to-Digital Converter (ADC) * Digital-to-Analog Converter (DAC) </br> <!-- == '''Interrupts and Exceptions ''' == --> </br> == '''Synchrnoization'''== </br> === H/W and S/W Synchronization === * busy wait synchronization * handshake interface </br> === Interrupt Synchronization === * interrupt synchronization * reentrant programming * buffered IO * periodic interrupt * periodic polling </br> ==''' Interfacing '''== </br> === Time Interfacing === * input capture * output compare </br> === Serial Interfacing === * Programming UART * Programming SPI * Programming I2C * Programming USB </br> === Analog Interfacing === * OP Amp * Filters * ADC * DAC </br> == '''Old materials''' == === '''Instruction Set Architecture''' === * ARM Instruction Set :: - Overview ([[Media:ARM.2ISA.1A.Overview.20180528.pdf |pdf]]) :: - Binary Encoding ([[Media:ARM.2ISA.2A.Encoding.20180528.pdf |pdf]]) :: - Assembler Format ([[Media:ARM.2ISA.3A.Format.20180528.pdf |pdf]]) * Thumb Instruction Set * ARM Assembly Language ([[Media:ESys3.1A.Assembly.20160608.pdf |pdf]]) * ARM Machine Language ([[Media:ESys3.2A.Machine.20160615.pdf |pdf]]) </br> </br> go to [ [[Electrical_%26_Computer_Engineering_Studies]] ] 2319qmm76g35rwqbzng2ul9zzfthybn 2414064 2414062 2022-08-13T09:31:30Z Young1lim 21186 /* ARM Assembly Programming (II) */ wikitext text/x-wiki == '''Background''' == '''Combinational and Sequential Circuits''' * [[Media:DD2.B.4..Adder.20131007.pdf |Adder]] * [[Media:DD3.A.1.LatchFF.20160308.pdf |Latches and Flipflops]] '''FSM''' * [[Media:DD3.A.3.FSM.20131030.pdf |FSM]] * [[Media:CArch.2.A.Bubble.20131021.pdf |FSM Example]] '''Tiny CPU Example''' * [[Media:CDsgn6.TinyCPU.2.A.ISA.20160511.pdf |Instruction Set]] * [[Media:CDsgn6.TinyCPU.2.B.DPath.20160502.pdf |Data Path]] * [[Media:CDsgn6.TinyCPU.2.C.CPath.20160427.pdf |Control Path]] * [[Media:CDsgn6.TinyCPU.2.D.Implement.20160513.pdf |FPGA Implementation]] </br> == '''Microprocessor Architecture''' == * ARM Architecture : - Programmer's Model ([[Media:ARM.1Arch.1A.Model.20180321.pdf |pdf]]) : - Pipelined Architecture ([[Media:ARM.1Arch.2A.Pipeline.20180419.pdf |pdf]]) * ARM Organization * ARM Cortex-M Processor Architecture * ARM Processor Cores </br> == '''Instruction Set Architecture''' == * ARM Instruction Set : - Overview ([[Media:ARM.2ISA.1A.Overview.20190611.pdf |pdf]]) : - Addressing Modes ([[Media:ARM.2ISA.2A.AddrMode.20191108.pdf |pdf]]) : - Multiple Transfer ([[Media:ARM.2ISA.3A.MTransfer.20190903.pdf |pdf]]) : - Assembler Format :: - Data Processing ([[Media:ARM.2ISA.4A.Proc.Format.20200204.pdf |pdf]]) :: - Data Transfer ([[Media:ARM.2ISA.4B.Trans.Format.20200205.pdf |pdf]]) :: - Coprocessor ([[Media:ARM.2ISA.4C.CoProc.Format.20191214.pdf |pdf]]) :: - Summary ([[Media:ARM.2ISA.4D.Summary.Format.20200205.pdf |pdf]]) : - Binary Encoding ([[Media:ARM.2ISA.5A.Encoding.201901105.pdf |pdf]]) * Thumb Instruction Set </br> == '''Assembly Programming''' == === ARM Assembly Programming (I) === * 1. Overview ([[Media:ARM.2ASM.1A.Overview.20200101.pdf |pdf]]) * 2. Example Programs ([[Media:ARM.2ASM.2A.Program.20200108.pdf |pdf]]) * 3. Addressing Modes ([[Media:ARM.2ASM.3A.Address.20200127.pdf |pdf]]) * 4. Data Transfer ([[Media:ARM.2ASM.4A.DTransfer.20200206.pdf |pdf]]) * 5. Data Processing ([[Media:ARM.2ASM.5A.DProcess.20200208.pdf |pdf]]) * 6. Control ([[Media:ARM.2ASM.6A.Control.20200215.pdf |pdf]]) * 7. Arrays ([[Media:ARM.2ASM.7A.Array.20200311.pdf |pdf]]) * 8. Data Structures ([[Media:ARM.2ASM.8A.DataStruct.20200718.pdf |pdf]]) * 9. Finite State Machines ([[Media:ARM.2ASM.9A.FSM.20200417.pdf |pdf]]) * 10. Functions ([[Media:ARM.2ASM.10A.Function.20210115.pdf |pdf]]) * 11. Parameter Passing ([[Media:ARM.2ASM.11A.Parameter.20210106.pdf |pdf]]) * 12. Stack Frames ([[Media:ARM.2ASM.12A.StackFrame.20210611.pdf |pdf]]) :: :: === ARM Assembly Programming (II) === :: * 1. Thumb instruction programming ([[Media:ARM.2ASM.Thumb.20210612.pdf |pdf]]) * 2. Exceptions ([[Media:ARM.2ASM.Exception.20220722.pdf |pdf]]) * 3. Exception Programming ([[Media:ARM.2ASM.ExceptionProg.20220311.pdf |pdf]]) * 4. Exception Handlers ([[Media:ARM.2ASM.ExceptionHandler.20220131.pdf |pdf]]) * 5. Interrupt Programming ([[Media:ARM.2ASM.InterruptProg.20211030.pdf |pdf]]) * 6. Interrupt Handlers ([[Media:ARM.2ASM.InterruptHandler.20211030.pdf |pdf]]) * 7. Vectored Interrupt Programming ([[Media:ARM.2ASM.VectorInt.20220811.pdf |pdf]]) </br> * ARM Assembly Exercises ([[Media:ESys.3.A.ARM-ASM-Exercise.20160608.pdf |A.pdf]], [[Media:ESys.3.B.Assembly.20160716.pdf |B.pdf]]) :: === ARM Assembly Programming (III) === * 1. Fixed point arithmetic (integer division) * 2. Floating point arithmetic * 3. Matrix multiply === ARM Linking === * arm link ([[Media:arm_link.20211208.pdf |pdf]]) </br> === ARM Microcontroller Programming === * 1. Input / Output * 2. Serial / Parallel Port Interfacing * 3. Analog I/O Interfacing * 4. Communication </br> == '''Memory Architecture''' == </br> === '''Memory Hierarchy''' === </br> === '''System and Peripheral Buses''' === </br> === '''Architectural Support''' === * High Level Languages * System Development * Operating Systems </br> == '''Peripheral Architecture''' == </br> === '''Vectored Interrupt Controller ''' === </br> === '''Timers ''' === * Timer / Counter ([[Media:ARM.4ASM.Timer.20220801.pdf |pdf]]) * Real Time Clock * Watchdog Timer </br> === '''Serial Bus''' === * '''UART''' : Universal Asynchronous Receiver/Transmitter ([[Media:ARM.4ASM.UART.20220809.pdf |pdf]]) * '''I2C''' : Inter-Integrated Circuit * '''SPI''' : Serial Peripheral Interface * '''USB''' : Universal Serial Bus Device Controller </br> === '''I/Os ''' === * General Purpose Input/Output ports (GPIO) * Pulse Width Modulator * Analog-to-Digital Converter (ADC) * Digital-to-Analog Converter (DAC) </br> <!-- == '''Interrupts and Exceptions ''' == --> </br> == '''Synchrnoization'''== </br> === H/W and S/W Synchronization === * busy wait synchronization * handshake interface </br> === Interrupt Synchronization === * interrupt synchronization * reentrant programming * buffered IO * periodic interrupt * periodic polling </br> ==''' Interfacing '''== </br> === Time Interfacing === * input capture * output compare </br> === Serial Interfacing === * Programming UART * Programming SPI * Programming I2C * Programming USB </br> === Analog Interfacing === * OP Amp * Filters * ADC * DAC </br> == '''Old materials''' == === '''Instruction Set Architecture''' === * ARM Instruction Set :: - Overview ([[Media:ARM.2ISA.1A.Overview.20180528.pdf |pdf]]) :: - Binary Encoding ([[Media:ARM.2ISA.2A.Encoding.20180528.pdf |pdf]]) :: - Assembler Format ([[Media:ARM.2ISA.3A.Format.20180528.pdf |pdf]]) * Thumb Instruction Set * ARM Assembly Language ([[Media:ESys3.1A.Assembly.20160608.pdf |pdf]]) * ARM Machine Language ([[Media:ESys3.2A.Machine.20160615.pdf |pdf]]) </br> </br> go to [ [[Electrical_%26_Computer_Engineering_Studies]] ] tqnenwystjls8ftcfh5gxwsy90k5vxm 2414066 2414064 2022-08-13T10:02:26Z Young1lim 21186 /* Serial Bus */ wikitext text/x-wiki == '''Background''' == '''Combinational and Sequential Circuits''' * [[Media:DD2.B.4..Adder.20131007.pdf |Adder]] * [[Media:DD3.A.1.LatchFF.20160308.pdf |Latches and Flipflops]] '''FSM''' * [[Media:DD3.A.3.FSM.20131030.pdf |FSM]] * [[Media:CArch.2.A.Bubble.20131021.pdf |FSM Example]] '''Tiny CPU Example''' * [[Media:CDsgn6.TinyCPU.2.A.ISA.20160511.pdf |Instruction Set]] * [[Media:CDsgn6.TinyCPU.2.B.DPath.20160502.pdf |Data Path]] * [[Media:CDsgn6.TinyCPU.2.C.CPath.20160427.pdf |Control Path]] * [[Media:CDsgn6.TinyCPU.2.D.Implement.20160513.pdf |FPGA Implementation]] </br> == '''Microprocessor Architecture''' == * ARM Architecture : - Programmer's Model ([[Media:ARM.1Arch.1A.Model.20180321.pdf |pdf]]) : - Pipelined Architecture ([[Media:ARM.1Arch.2A.Pipeline.20180419.pdf |pdf]]) * ARM Organization * ARM Cortex-M Processor Architecture * ARM Processor Cores </br> == '''Instruction Set Architecture''' == * ARM Instruction Set : - Overview ([[Media:ARM.2ISA.1A.Overview.20190611.pdf |pdf]]) : - Addressing Modes ([[Media:ARM.2ISA.2A.AddrMode.20191108.pdf |pdf]]) : - Multiple Transfer ([[Media:ARM.2ISA.3A.MTransfer.20190903.pdf |pdf]]) : - Assembler Format :: - Data Processing ([[Media:ARM.2ISA.4A.Proc.Format.20200204.pdf |pdf]]) :: - Data Transfer ([[Media:ARM.2ISA.4B.Trans.Format.20200205.pdf |pdf]]) :: - Coprocessor ([[Media:ARM.2ISA.4C.CoProc.Format.20191214.pdf |pdf]]) :: - Summary ([[Media:ARM.2ISA.4D.Summary.Format.20200205.pdf |pdf]]) : - Binary Encoding ([[Media:ARM.2ISA.5A.Encoding.201901105.pdf |pdf]]) * Thumb Instruction Set </br> == '''Assembly Programming''' == === ARM Assembly Programming (I) === * 1. Overview ([[Media:ARM.2ASM.1A.Overview.20200101.pdf |pdf]]) * 2. Example Programs ([[Media:ARM.2ASM.2A.Program.20200108.pdf |pdf]]) * 3. Addressing Modes ([[Media:ARM.2ASM.3A.Address.20200127.pdf |pdf]]) * 4. Data Transfer ([[Media:ARM.2ASM.4A.DTransfer.20200206.pdf |pdf]]) * 5. Data Processing ([[Media:ARM.2ASM.5A.DProcess.20200208.pdf |pdf]]) * 6. Control ([[Media:ARM.2ASM.6A.Control.20200215.pdf |pdf]]) * 7. Arrays ([[Media:ARM.2ASM.7A.Array.20200311.pdf |pdf]]) * 8. Data Structures ([[Media:ARM.2ASM.8A.DataStruct.20200718.pdf |pdf]]) * 9. Finite State Machines ([[Media:ARM.2ASM.9A.FSM.20200417.pdf |pdf]]) * 10. Functions ([[Media:ARM.2ASM.10A.Function.20210115.pdf |pdf]]) * 11. Parameter Passing ([[Media:ARM.2ASM.11A.Parameter.20210106.pdf |pdf]]) * 12. Stack Frames ([[Media:ARM.2ASM.12A.StackFrame.20210611.pdf |pdf]]) :: :: === ARM Assembly Programming (II) === :: * 1. Thumb instruction programming ([[Media:ARM.2ASM.Thumb.20210612.pdf |pdf]]) * 2. Exceptions ([[Media:ARM.2ASM.Exception.20220722.pdf |pdf]]) * 3. Exception Programming ([[Media:ARM.2ASM.ExceptionProg.20220311.pdf |pdf]]) * 4. Exception Handlers ([[Media:ARM.2ASM.ExceptionHandler.20220131.pdf |pdf]]) * 5. Interrupt Programming ([[Media:ARM.2ASM.InterruptProg.20211030.pdf |pdf]]) * 6. Interrupt Handlers ([[Media:ARM.2ASM.InterruptHandler.20211030.pdf |pdf]]) * 7. Vectored Interrupt Programming ([[Media:ARM.2ASM.VectorInt.20220811.pdf |pdf]]) </br> * ARM Assembly Exercises ([[Media:ESys.3.A.ARM-ASM-Exercise.20160608.pdf |A.pdf]], [[Media:ESys.3.B.Assembly.20160716.pdf |B.pdf]]) :: === ARM Assembly Programming (III) === * 1. Fixed point arithmetic (integer division) * 2. Floating point arithmetic * 3. Matrix multiply === ARM Linking === * arm link ([[Media:arm_link.20211208.pdf |pdf]]) </br> === ARM Microcontroller Programming === * 1. Input / Output * 2. Serial / Parallel Port Interfacing * 3. Analog I/O Interfacing * 4. Communication </br> == '''Memory Architecture''' == </br> === '''Memory Hierarchy''' === </br> === '''System and Peripheral Buses''' === </br> === '''Architectural Support''' === * High Level Languages * System Development * Operating Systems </br> == '''Peripheral Architecture''' == </br> === '''Vectored Interrupt Controller ''' === </br> === '''Timers ''' === * Timer / Counter ([[Media:ARM.4ASM.Timer.20220801.pdf |pdf]]) * Real Time Clock * Watchdog Timer </br> === '''Serial Bus''' === * '''UART''' : Universal Asynchronous Receiver/Transmitter ([[Media:ARM.4ASM.UART.20220810.pdf |pdf]]) * '''I2C''' : Inter-Integrated Circuit * '''SPI''' : Serial Peripheral Interface * '''USB''' : Universal Serial Bus Device Controller </br> === '''I/Os ''' === * General Purpose Input/Output ports (GPIO) * Pulse Width Modulator * Analog-to-Digital Converter (ADC) * Digital-to-Analog Converter (DAC) </br> <!-- == '''Interrupts and Exceptions ''' == --> </br> == '''Synchrnoization'''== </br> === H/W and S/W Synchronization === * busy wait synchronization * handshake interface </br> === Interrupt Synchronization === * interrupt synchronization * reentrant programming * buffered IO * periodic interrupt * periodic polling </br> ==''' Interfacing '''== </br> === Time Interfacing === * input capture * output compare </br> === Serial Interfacing === * Programming UART * Programming SPI * Programming I2C * Programming USB </br> === Analog Interfacing === * OP Amp * Filters * ADC * DAC </br> == '''Old materials''' == === '''Instruction Set Architecture''' === * ARM Instruction Set :: - Overview ([[Media:ARM.2ISA.1A.Overview.20180528.pdf |pdf]]) :: - Binary Encoding ([[Media:ARM.2ISA.2A.Encoding.20180528.pdf |pdf]]) :: - Assembler Format ([[Media:ARM.2ISA.3A.Format.20180528.pdf |pdf]]) * Thumb Instruction Set * ARM Assembly Language ([[Media:ESys3.1A.Assembly.20160608.pdf |pdf]]) * ARM Machine Language ([[Media:ESys3.2A.Machine.20160615.pdf |pdf]]) </br> </br> go to [ [[Electrical_%26_Computer_Engineering_Studies]] ] pgofm43a8cpp4i27boyi0fa76xskepx 2414068 2414066 2022-08-13T10:03:36Z Young1lim 21186 /* Serial Bus */ wikitext text/x-wiki == '''Background''' == '''Combinational and Sequential Circuits''' * [[Media:DD2.B.4..Adder.20131007.pdf |Adder]] * [[Media:DD3.A.1.LatchFF.20160308.pdf |Latches and Flipflops]] '''FSM''' * [[Media:DD3.A.3.FSM.20131030.pdf |FSM]] * [[Media:CArch.2.A.Bubble.20131021.pdf |FSM Example]] '''Tiny CPU Example''' * [[Media:CDsgn6.TinyCPU.2.A.ISA.20160511.pdf |Instruction Set]] * [[Media:CDsgn6.TinyCPU.2.B.DPath.20160502.pdf |Data Path]] * [[Media:CDsgn6.TinyCPU.2.C.CPath.20160427.pdf |Control Path]] * [[Media:CDsgn6.TinyCPU.2.D.Implement.20160513.pdf |FPGA Implementation]] </br> == '''Microprocessor Architecture''' == * ARM Architecture : - Programmer's Model ([[Media:ARM.1Arch.1A.Model.20180321.pdf |pdf]]) : - Pipelined Architecture ([[Media:ARM.1Arch.2A.Pipeline.20180419.pdf |pdf]]) * ARM Organization * ARM Cortex-M Processor Architecture * ARM Processor Cores </br> == '''Instruction Set Architecture''' == * ARM Instruction Set : - Overview ([[Media:ARM.2ISA.1A.Overview.20190611.pdf |pdf]]) : - Addressing Modes ([[Media:ARM.2ISA.2A.AddrMode.20191108.pdf |pdf]]) : - Multiple Transfer ([[Media:ARM.2ISA.3A.MTransfer.20190903.pdf |pdf]]) : - Assembler Format :: - Data Processing ([[Media:ARM.2ISA.4A.Proc.Format.20200204.pdf |pdf]]) :: - Data Transfer ([[Media:ARM.2ISA.4B.Trans.Format.20200205.pdf |pdf]]) :: - Coprocessor ([[Media:ARM.2ISA.4C.CoProc.Format.20191214.pdf |pdf]]) :: - Summary ([[Media:ARM.2ISA.4D.Summary.Format.20200205.pdf |pdf]]) : - Binary Encoding ([[Media:ARM.2ISA.5A.Encoding.201901105.pdf |pdf]]) * Thumb Instruction Set </br> == '''Assembly Programming''' == === ARM Assembly Programming (I) === * 1. Overview ([[Media:ARM.2ASM.1A.Overview.20200101.pdf |pdf]]) * 2. Example Programs ([[Media:ARM.2ASM.2A.Program.20200108.pdf |pdf]]) * 3. Addressing Modes ([[Media:ARM.2ASM.3A.Address.20200127.pdf |pdf]]) * 4. Data Transfer ([[Media:ARM.2ASM.4A.DTransfer.20200206.pdf |pdf]]) * 5. Data Processing ([[Media:ARM.2ASM.5A.DProcess.20200208.pdf |pdf]]) * 6. Control ([[Media:ARM.2ASM.6A.Control.20200215.pdf |pdf]]) * 7. Arrays ([[Media:ARM.2ASM.7A.Array.20200311.pdf |pdf]]) * 8. Data Structures ([[Media:ARM.2ASM.8A.DataStruct.20200718.pdf |pdf]]) * 9. Finite State Machines ([[Media:ARM.2ASM.9A.FSM.20200417.pdf |pdf]]) * 10. Functions ([[Media:ARM.2ASM.10A.Function.20210115.pdf |pdf]]) * 11. Parameter Passing ([[Media:ARM.2ASM.11A.Parameter.20210106.pdf |pdf]]) * 12. Stack Frames ([[Media:ARM.2ASM.12A.StackFrame.20210611.pdf |pdf]]) :: :: === ARM Assembly Programming (II) === :: * 1. Thumb instruction programming ([[Media:ARM.2ASM.Thumb.20210612.pdf |pdf]]) * 2. Exceptions ([[Media:ARM.2ASM.Exception.20220722.pdf |pdf]]) * 3. Exception Programming ([[Media:ARM.2ASM.ExceptionProg.20220311.pdf |pdf]]) * 4. Exception Handlers ([[Media:ARM.2ASM.ExceptionHandler.20220131.pdf |pdf]]) * 5. Interrupt Programming ([[Media:ARM.2ASM.InterruptProg.20211030.pdf |pdf]]) * 6. Interrupt Handlers ([[Media:ARM.2ASM.InterruptHandler.20211030.pdf |pdf]]) * 7. Vectored Interrupt Programming ([[Media:ARM.2ASM.VectorInt.20220811.pdf |pdf]]) </br> * ARM Assembly Exercises ([[Media:ESys.3.A.ARM-ASM-Exercise.20160608.pdf |A.pdf]], [[Media:ESys.3.B.Assembly.20160716.pdf |B.pdf]]) :: === ARM Assembly Programming (III) === * 1. Fixed point arithmetic (integer division) * 2. Floating point arithmetic * 3. Matrix multiply === ARM Linking === * arm link ([[Media:arm_link.20211208.pdf |pdf]]) </br> === ARM Microcontroller Programming === * 1. Input / Output * 2. Serial / Parallel Port Interfacing * 3. Analog I/O Interfacing * 4. Communication </br> == '''Memory Architecture''' == </br> === '''Memory Hierarchy''' === </br> === '''System and Peripheral Buses''' === </br> === '''Architectural Support''' === * High Level Languages * System Development * Operating Systems </br> == '''Peripheral Architecture''' == </br> === '''Vectored Interrupt Controller ''' === </br> === '''Timers ''' === * Timer / Counter ([[Media:ARM.4ASM.Timer.20220801.pdf |pdf]]) * Real Time Clock * Watchdog Timer </br> === '''Serial Bus''' === * '''UART''' : Universal Asynchronous Receiver/Transmitter ([[Media:ARM.4ASM.UART.20220811.pdf |pdf]]) * '''I2C''' : Inter-Integrated Circuit * '''SPI''' : Serial Peripheral Interface * '''USB''' : Universal Serial Bus Device Controller </br> === '''I/Os ''' === * General Purpose Input/Output ports (GPIO) * Pulse Width Modulator * Analog-to-Digital Converter (ADC) * Digital-to-Analog Converter (DAC) </br> <!-- == '''Interrupts and Exceptions ''' == --> </br> == '''Synchrnoization'''== </br> === H/W and S/W Synchronization === * busy wait synchronization * handshake interface </br> === Interrupt Synchronization === * interrupt synchronization * reentrant programming * buffered IO * periodic interrupt * periodic polling </br> ==''' Interfacing '''== </br> === Time Interfacing === * input capture * output compare </br> === Serial Interfacing === * Programming UART * Programming SPI * Programming I2C * Programming USB </br> === Analog Interfacing === * OP Amp * Filters * ADC * DAC </br> == '''Old materials''' == === '''Instruction Set Architecture''' === * ARM Instruction Set :: - Overview ([[Media:ARM.2ISA.1A.Overview.20180528.pdf |pdf]]) :: - Binary Encoding ([[Media:ARM.2ISA.2A.Encoding.20180528.pdf |pdf]]) :: - Assembler Format ([[Media:ARM.2ISA.3A.Format.20180528.pdf |pdf]]) * Thumb Instruction Set * ARM Assembly Language ([[Media:ESys3.1A.Assembly.20160608.pdf |pdf]]) * ARM Machine Language ([[Media:ESys3.2A.Machine.20160615.pdf |pdf]]) </br> </br> go to [ [[Electrical_%26_Computer_Engineering_Studies]] ] bfpevod9a2he9zmkvzsw7slpglaivue 1 233628 2413970 2413917 2022-08-12T14:44:03Z Dave Braunschweig 426084 Reverted edits by [[Special:Contributions/Faggetmutilator|Faggetmutilator]] ([[User_talk:Faggetmutilator|talk]]) to last version by [[User:Ardenguo|Ardenguo]] using [[Wikiversity:Rollback|rollback]] wikitext text/x-wiki == To-dos == Drop suggestions and next to-dos in their respective sections. For each section, please add four tildes (<nowiki>~~~~</nowiki>). This is to add a timestamp and your username next to your suggestion. === Demographic information === "Base rates of ASD in children and adolescents in different populations and clinical settings" needs work -Lizzie "National prevalence via CDC's ADDM sites is outdated, now 1 in 54 ~1.9%; North Carolina prevalence is 1 in 39 ~2.6%; breakdown by sex and race/ethnicity also available to be updated (2016 surveillance - Maenner et al., 2020)" - MC === Diagnosis === "Screening instruments and diagnostic interviews" needs work. -Lizzie "Given the high prevalence of co-occurring psychopathology with ASD, it could be really clinically useful to include screeners (for anxiety and depression in particular) which have been validated for autistic individuals. This would be helpful not only for clinicians to routinely screen for with autistic clients but would also be useful for clinicians unfamiliar with autism to utilize (e.g. a community mental health provider whose newest referral for anxiety treatment happens to be autistic.)" - MC ==2022 Summer Audit== ===Preparation phase === ====Diagnostic criteria for autism spectrum disorder==== DSM-IV link is broken- doesn't have a page or is written wrong [[User:Hope Holloway|Hope Holloway]] ([[User talk:Hope Holloway|discuss]] • [[Special:Contributions/Hope Holloway|contribs]]) 13:58, 16 June 2022 (UTC) ====Base rates of ASD in children and adolescents in different populations and clinical settings==== some columns aren't filled out completely [[User:Hope Holloway|Hope Holloway]] ([[User talk:Hope Holloway|discuss]] • [[Special:Contributions/Hope Holloway|contribs]]) 14:01, 16 June 2022 (UTC) ===Prediction phase === ====Psychometric properties of screening instruments for autism spectrum disorder==== inter-rate reliability, test-retest reliability, construct validity, and content validity columns are not filled out [[User:Hope Holloway|Hope Holloway]] ([[User talk:Hope Holloway|discuss]] • [[Special:Contributions/Hope Holloway|contribs]]) 13:58, 16 June 2022 (UTC) ====Likelihood ratios and AUCs of screening measures for ASD==== last four columns aren't filled out [[User:Hope Holloway|Hope Holloway]] ([[User talk:Hope Holloway|discuss]] • [[Special:Contributions/Hope Holloway|contribs]]) 13:58, 16 June 2022 (UTC) ====Interpreting autism screening measure scores==== ===Prescription phase === ====Gold standard diagnostic interviews==== ====Recommended diagnostic interviews for autism spectrum disorder==== table incomplete!!! [[User:Hope Holloway|Hope Holloway]] ([[User talk:Hope Holloway|discuss]] • [[Special:Contributions/Hope Holloway|contribs]]) 13:58, 16 June 2022 (UTC) ===Process phase === ====Process measures==== ====Outcome and severity measures==== ====Treatment==== ===External resources=== first link is a little weird i don’t know if i just don't know how to work it or what but its kind of confusing [[User:Hope Holloway|Hope Holloway]] ([[User talk:Hope Holloway|discuss]] • [[Special:Contributions/Hope Holloway|contribs]]) 14:19, 16 June 2022 (UTC) Do you think adding in this [https://embrace-autism.com/ link] would be helpful? It goes to the Embrace Autism site which allows people to take widely used, empirically validated tests online that can give an indication of whether they might be autistic.--[[User:Ardenguo|Ardenguo]] ([[User talk:Ardenguo|discuss]] • [[Special:Contributions/Ardenguo|contribs]]) 23:37, 11 August 2022 (UTC) ===References=== 447tcyt3ajg9i7bybr6g1g2vl4gk190 0 234479 2413990 2398320 2022-08-12T16:43:11Z Marshallsumter 311529 wikitext text/x-wiki [[Image:Media 1.ogv|thumb|right|250px|On July 19, 2012, an eruption occurred on the sun that produced a moderately powerful solar flare and a dazzling magnetic display known as coronal rain. Credit: NASA Goddard Space Flight Center, Music: 'Thunderbolt' by Lars Leonhard, courtesy of artist.{{tlx|free media}}]] A [[coronal cloud]] is a cloud, or cloud-like, natural astronomical entity, composed of plasma and usually associated with a star or other astronomical object where the temperature is such that X-rays are emitted. While small coronal clouds are above the photosphere of many different visual spectral type stars, others occupy parts of the [[interstellar medium]] (ISM), extending sometimes millions of kilometers into space, or thousands of light-years, depending on the size of the associated object such as a galaxy. {{clear}} ==Auroras== {{main|Plasmas/Plasma objects/Auroras}} [[Image:Aurora Iceland 2015 Carlos Gauna 625.jpg|thumb|right|300px|This dramatic panorama shows a colourful, shimmering auroral curtain reflected in a placid Icelandic lake. Credit: Carlos Gauna. {{tlx|fairuse}}]] '''Auroras''' can be caused by electrons being absorbed into an atmosphere. The "dramatic panorama [on the right shows a colorful], shimmering auroral curtain reflected in a placid Icelandic lake. The image was taken on 18 March 2015 by Carlos Gauna, near Jökulsárlón Glacier Lagoon in southern Iceland."<ref name=ESAGauna>{{ cite book |author=European Space Agency |title=Aurora over Icelandic Lake |publisher=ESA |location= |date=9 April 2015 |url=http://sci.esa.int/cluster/55767-aurora-over-icelandic-lake/ |accessdate=2015-04-12 }}</ref> "The celestial display was generated by a coronal mass ejection, or CME, on 15 March. Sweeping across the inner Solar System at some 3 million km per hour, the eruption reached Earth, 150 million kilometres away, in only two days. The gaseous cloud collided with Earth’s magnetic field at around 04:30 GMT on 17 March."<ref name=ESAGauna/> "When the charged particles from the Sun penetrate Earth's magnetic shield, they are channelled downwards along the magnetic field lines until they strike atoms of gas high in the atmosphere. Like a giant fluorescent neon lamp, the interaction with excited oxygen atoms generates a green or, more rarely, red glow in the night sky, while excited nitrogen atoms yield blue and purple colours."<ref name=ESAGauna/> "Auroral displays are not just decorative distractions. They are most frequent when the Sun's activity nears its peak roughly every 11 years. At such times, the inflow of high-energy particles and the buffeting of Earth’s magnetic field may sometimes cause power blackouts, disruption of radio communications, damage to satellites and even threaten astronaut safety."<ref name=ESAGauna/> {{clear}} ==Coronas== [[Image:PSM V60 D316 The solar corona.png|thumb|right|250px|The solar corona is photographed between 1901-2. Credit: [http://www.archive.org/details/popularsciencemo60newy Popular Science Monthly Volume 60].{{tlx|free media}}]] [[Image:Cp19halphajune29.png|thumb|left|250px|This is a coronagraph/polarimeter image of the solar corona on June 29, 1980, in H alpha light. Credit: NASA.{{tlx|free media}}]] '''Def.''' "[t]he luminous plasma atmosphere of the Sun or other star, extending millions of kilometres into space, most easily seen during a total solar eclipse"<ref name=CoronaWikt>{{ cite web |title=corona |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=6 September 2015 |url=https://en.wiktionary.org/wiki/corona |accessdate=2015-09-10 }}</ref> is called a '''corona''', or '''stellar corona'''. "Beginning with the daguerreotype of the corona of 1851, the Reverend Lecturer had thrown on the screen pictures illustrating the form of the corona in different years. The drawings of those of 1867, 1878, and 1900 all showed long equatorial extensions with openings at the solar poles filled with beautiful rays."<ref name=Cortie>{{ cite journal |author=A. L. Cortie |title=Synopsis of Lecture on "The Solar Corona" by the Rev. A.L. Cortie to the Members of the North-Western Branch (Manchester) on 7th November 1900 |journal=Journal of the British Astronomical Association |month=December |year=1900 |volume=11 |issue=12 |pages=77-8 |url=http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1900JBAA...11...77C&link_type=ARTICLE&db_key=AST&high= |arxiv= |bibcode=1900JBAA...11...77C |doi= |pmid= |accessdate=2011-11-09 }}</ref> "The intermediate years, as, for example, 1883, 1886, and 1896 showed the four groups of synclinals which mainly constitute the corona gradually descending towards the equator of the sun, with a corresponding opening of the polar regions."<ref name=Cortie/> "Some of the theories of the solar corona were then illustrated and discussed."<ref name=Cortie/> # "The corona is not of the nature of an atmosphere round the sun, for the pressure at the sun's limb would be enormous, while the thinness of the chromospheric lines show that it is not."<ref name=Cortie/> # "comets, such as that of 1843, have approached the sun with enormous velocities within the region of the prominences without suffering disruption or retardation."<ref name=Cortie/> # "If not an atmosphere of particles of gas, still less is it an atmosphere of solid stones or meteorites."<ref name=Cortie/> # "Meteor streams do circle round the sun, but there is no reason why the positions of the orbits, or the intrinsic brightness of such streams should vary with the sun-spot period."<ref name=Cortie/> # "the appearance of the corona does not seem to be such as the projection of meteor streams upon the celestial vault would give."<ref name=Cortie/> # "Prof. Schaeberle has proposed a mechanical origin of the solar corona, due to the forces of ejection of particles from the solar limb, as evidenced by the prominences, and the force of gravity under the particular conditions of the solar rotation and the inclination of its axis to the earth's orbit."<ref name=Cortie/> # "The electrical theory of the corona does not negative the mechanical theory, but supplements it. In addition to the forces of gravity and ejection, it takes account of the repulsive force which the sun exerts on matter which has the same electrical sign as itself, and which has been ejected from it."<ref name=Cortie/> # "it would seem that the solar corona is of the nature of an electrical aurora round the sun."<ref name=Cortie/> # "the coronoidal discharges in poor vacua obtained by Prof. Pupin about an insulated metal ball are exceedingly like the rays and streamers of the solar corona."<ref name=Cortie/> The Sun's hot [[w:corona|corona]] continuously expands in space creating the [[w:solar wind|solar wind]], a stream of charged particles that extends to the [[w:heliopause|heliopause]] at roughly 100 [[w:astronomical units|astronomical units]]. The bubble in the [[interstellar medium]] formed by the solar wind, the [[w:heliosphere|heliosphere]], is the largest continuous structure in the Solar System.<ref>{{ cite web |date=22 April 2003 |title=A Star with two North Poles |url=http://science.nasa.gov/headlines/y2003/22apr_currentsheet.htm |work=Science @ NASA |publisher=NASA }}</ref><ref name=Riley>{{ cite journal |last=Riley |first=P. |last2=Linker |first2=J. A. |last3=Mikić |first3=Z. |year=2002 |title=Modeling the heliospheric current sheet: Solar cycle variations |url=http://ulysses.jpl.nasa.gov/science/monthly_highlights/2002-July-2001JA000299.pdf |journal=Journal of Geophysical Research |volume=107 |issue=A7 |pages=SSH 8–1 |bibcode=2002JGRA.107g.SSH8R |doi=10.1029/2001JA000299 |id=CiteID 1136 }}</ref> The sun's [[w:corona|corona]] is constantly being lost to space, creating what is essentially a very thin [[w:atmosphere|atmosphere]] throughout the [[Solar System]]. The movement of mass ejected from the Sun is known as the [[w:solar wind|solar wind]]. Inconsistencies in this wind and larger events on the surface of the star, such as [[w:coronal mass ejection|coronal mass ejection]]s, form a system that has features analogous to conventional weather systems (such as pressure and wind) and is generally known as [[w:space weather|space weather]]. Coronal mass ejections have been tracked as far out in the [[w:solar system|solar system]] as [[Saturn]].<ref name=Christensen>Bill Christensen. [http://www.space.com/businesstechnology/technology/technovel_shock_041105.html Shock to the (Solar) System: Coronal Mass Ejection Tracked to Saturn.] Retrieved on 28 June 2008.</ref> The activity of this system can affect planetary [[w:atmospheres|atmospheres]] and occasionally surfaces. The interaction of the [[w:solar wind|solar wind]] with the terrestrial atmosphere can produce spectacular [[w:Aurora (astronomy)|aurorae]],<ref name=AlaskaReport>AlaskaReport. [http://alaskareport.com/science10043.htm What Causes the Aurora Borealis?] Retrieved on 28 June 2008.</ref> and can play havoc with electrically sensitive systems such as [[w:Electric power transmission|electricity grids]] and radio signals. {{clear}} ==Coronal arcades== [[Image:Coronal_arcade.png|thumb|right|250px|This is a TRACE image of the coronal arcade structure in the flare on Bastille Day, 1998. Credit: NASA.{{tlx|free media}}]] '''Def.''' a close collection of loops in a cylindrical structure is called an '''arcade'''. The TRACE image at right "is from near flare maximum (11:00 UT) and has a width of 230,000 km [...] how in the world can the footpoints of the arcade have such a clearly-organized pattern whose scale greatly exceeds the known scales of the largest convective scales known in the photosphere?"<ref name=Handy>{{ cite book |author=Brian Handy, Hugh Hudson |title=Super Regions |publisher=University of Montana |location=Helena, Montana, USA |date=July 14, 2000 |url=http://solar.physics.montana.edu/nuggets/2000/000714/000714.html |accessdate=2012-11-09 }}</ref> "The most obvious coronal signatures of CMEs in the low corona are the arcades of bright loops that develop after the CME material has erupted [...] nearly all (92%) EIT post-eruptive arcades from 1997 – 2002 were associated with LASCO CMEs [...] The activity associated with halo CMEs includes the formation of dimming regions, long-lived loop arcades, flaring active regions, large-scale coronal waves and filament eruptions".<ref name=Webb>{{ cite journal |author=David F. Webb, Timothy A. Howard |title=Coronal Mass Ejections: Observations |journal=Living Reviews in Solar Physics |year=2012 |volume=9 |issue= |pages=3 |url=http://www.boulder.swri.edu/~howard/Papers/2012_lrsp.pdf |arxiv= |bibcode= |doi= |pmid= |accessdate=2012-11-11 }}</ref> {{clear}} ==Coronal clouds== [[Image:2011 03 sun030311.jpg|thumb|right|200px|This image is taken in Hα of the Sun and above showing a cloud above a sunspot. Credit: Alan Friedman.{{tlx|fairuse}}]] "Coronal clouds, type IIIg, form in space above a spot area and rain streamers upon it."<ref name=Pettit43>{{ cite journal |author=Edison Pettit |title=The Properties of Solar Prominences as Related to Type |journal=Astrophysical Journal |month=July |year=1943 |volume=98 |issue=7 |pages=6-19 |url= |bibcode=1943ApJ....98....6P |doi=10.1086/144539 |pmid= |accessdate=2011-08-01 }}</ref> "[C]oronal magnetic bottles, produced by flares, [may] serve as temporary traps for solar cosmic rays ... It is the expansion of these bottles at velocities of 300–500 km/s which allows fast azimuthal propagation of solar cosmic rays independent of energy. A coronagraph on [[w:OSO 7|Os 7]] observed a coronal cloud which was associated with bifurcation of the underlying coronal structure."<ref name="Schatten">{{cite journal |author=K. H. Schatten, D. J. Mullan |title=Fast azimuthal transport of solar cosmic rays via a coronal magnetic bottle |journal=Journal of Geophysical Research |month=December 1, |year=1977 |volume=82 |issue=35 |pages=5609-20 |url=http://www.agu.org/pubs/crossref/1977/JA082i035p05609.shtml |arxiv= |bibcode= |doi=10.1029/JA082i035p05609 |pmid= |accessdate=2013-07-07 }}</ref> In a coronal cloud are [[Magnetohydrodynamics|magnetohydrodynamic]] plasma flux tubes along magnetic field lines.<ref name=Aschwanden/> {{clear}} ==Coronal heating== "The photosphere of the Sun has an effective temperature of 5,570 K<ref name=Massey>{{ cite journal |author=Massey P |author2=Silva DR |author3=Levesque EM |author4=Plez B |author5=Olsen KAG |author6=Clayton GC |author7=Meynet G |author8=Maeder A |title=Red Supergiants in the Andromeda Galaxy (M31) |journal=The Astrophysical Journal |volume=703 |year=2009 |issue=1 |page=420 |doi=10.1088/0004-637X/703/1/420 |bibcode=2009ApJ...703..420M }}</ref> yet its corona has an average temperature of 1–2 x 10⁶ K.<ref name=Erdelyi>{{ cite journal |author=Erdèlyi R |author2=Ballai I |title=Heating of the solar and stellar coronae: a review |year=2007 |journal=Astron Nachr |volume=328 |issue=8 |page=726 |doi=10.1002/asna.200710803 |bibcode=2007AN....328..726E }}</ref> However, the hottest regions are 8–20 x 10⁶ K.<ref name=Erdelyi/> The high temperature of the corona shows that it is heated by something other than direct [[w:Heat conduction|heat conduction]] from the photosphere.<ref name=Russell2001>{{ cite book |author=Russell CT |title=Space Weather (Geophysical Monograph) |year=2001 |publisher=American Geophysical Union |chapter=Solar wind and interplanetary magnetic field: A tutorial |editor=Song, Paul |editor2=Singer, Howard J. |editor3=Siscoe, George L. |isbn=9780875909844 |pages=73–88 |url=http://www-ssc.igpp.ucla.edu/personnel/russell/papers/SolWindTutorial.pdf }}</ref> It is thought that the energy necessary to heat the corona is provided by turbulent motion in the convection zone below the photosphere, and two main mechanisms have been proposed to explain coronal heating.<ref name=Erdelyi/> The first is [[w:wave|wave]] heating, in which sound, gravitational or magnetohydrodynamic waves are produced by turbulence in the convection zone.<ref name=Erdelyi/> These waves travel upward and dissipate in the corona, depositing their energy in the ambient gas in the form of heat.<ref name=Alfven>{{ cite journal |author=Alfvén H |title=Magneto-hydrodynamic waves, and the heating of the solar corona |bibcode=1947MNRAS.107..211A |journal=Monthly Notices of the Royal Astronomical Society |volume=107 |page=211 |year=1947 }}</ref> The other is [[w:magnetic field|magnetic]] heating, in which magnetic energy is continuously built up by photospheric motion and released through [[w:magnetic reconnection|magnetic reconnection]] in the form of large [[w:solar flare|solar flare]]s and myriad similar but smaller events—[[w:nanoflares|nanoflares]].<ref name=Parker2>{{ cite journal |author=Parker EN |title=Nanoflares and the solar X-ray corona |journal=The Astrophysical Journal |volume=330 |page=474 |year=1988 |doi=10.1086/166485 |bibcode=1988ApJ...330..474P }}</ref> Currently, it is unclear whether waves are an efficient heating mechanism. All waves except [[w:Alfvén wave|Alfvén wave]]s have been found to dissipate or refract before reaching the corona.<ref name=Sturrock>{{ cite journal |author=Sturrock PA, Uchida Y |title=Coronal heating by stochastic magnetic pumping |journal=The Astrophysical Journal |volume=246 |page=331 |year=1981 |doi=10.1086/158926 |bibcode=1981ApJ...246..331S }}</ref> In addition, Alfvén waves do not easily dissipate in the corona. Current research focus has therefore shifted towards flare heating mechanisms.<ref name=Erdelyi/>"<ref name=XrayAstronomy>{{ cite web |title=X-ray astronomy, In: ''Wikipedia'' |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=June 11, 2012 |url=http://en.wikipedia.org/wiki/X-ray_astronomy |accessdate=2012-06-29 }}</ref> ==Coronal loops== [[Image:AR1520 and Shimmering Coronal Loops.ogv|thumb|250px|right|This movie shows the evolution of active region 1520, including coronal loops. Credit: NASA/Goddard Space Flight Center.{{tlx|free media}}]] [[Image:Traceimage.jpg|thumb|right|250px|This image of coronal loops observed by the Transition Region And Coronal Explorer ([[w:TRACE|TRACE]]) shows that not all rays travel in straight lines. Credit: NASA.{{tlx|free media}}]] Coronal loops have become very important when trying to understand the current ''coronal heating problem''. Coronal loops are highly radiating sources of plasma and therefore easy to observe by instruments such as ''TRACE''; they are highly observable ''laboratories'' to study phenomena such as solar oscillations, wave activity and [[w:Nanoflares|nanoflares]]. However, it remains difficult to find a solution to the coronal heating problem as these structures are being observed remotely, where many ambiguities are present (i.e. radiation contributions along the [line-of-sight propagation] LOS). ''In-situ'' measurements are required before a definitive answer can be arrived at, but due to the high plasma temperatures in the corona, in-situ measurements are impossible (at least for the time being). The next mission of the Nasa [[w:Solar Probe Plus|Solar Probe Plus]] will approach the Sun very closely allowing more direct observations. "The peak continuum intensity was always at the loop tops."<ref name=Zirin1981>{{ cite journal |author=H. Zirin |author2=U. Feldman |author3=G. A. Doschek |author4=S. Kane |title=On the relationship between soft X-rays and Hα-emitting structures during a solar flare |journal=The Astrophysical Journal |month=May 15, |year=1981 |volume=246 |issue=05 |pages=321-30 |url=http://adsabs.harvard.edu/full/1981ApJ...246..321Z |arxiv= |bibcode=1981ApJ...246..321Z |doi=10.1086/158925 |pmid= |accessdate=2013-07-10 }}</ref> The population of coronal loops can be directly linked with the [[w:solar cycle|solar cycle]]; it is for this reason coronal loops are often found with sunspots at their footpoints. Coronal loops project through the [[w:chromosphere|chromosphere]] and [[w:transition region|transition region]], extending high into the [[Coronal cloud|corona]]. Coronal loops have a wide variety of temperatures along their lengths. Loops existing at temperatures below 1&nbsp;MK are generally known as cool loops, those existing at around 1&nbsp;MK are known as warm loops, and those beyond 1&nbsp;MK are known as hot loops. Naturally, these different categories radiate at different wavelengths.<ref name=Vourlidas>{{cite journal | author = A. Vourlidas |author2=J. A. Klimchuk |author3=C. M. Korendyke |author4=T. D. Tarbell |author5=B. N. Handy | title = On the correlation between coronal and lower transition region structures at arcsecond scales | journal = The Astrophysical Journal | volume = 563 | issue = 1 | pages = 374–80 | year = 2001 | doi = 10.1086/323835 | bibcode=2001ApJ...563..374V }}</ref> Coronal loops populate both active and quiet regions of the solar surface. Active regions on the solar surface take up small areas but produce the majority of activity and 82% of the total coronal heating energy.<ref name=Aschwanden>{{ cite journal | author = M. J. Aschwanden | title = An evaluation of coronal heating models for Active Regions based on Yohkoh, SOHO, and TRACE observations | journal = The Astrophysical Journal | volume = 560 | issue = 2 | pages = 1035–44 | year = 2001 | doi = 10.1086/323064 | bibcode=2001ApJ...560.1035A }}</ref> The quiet Sun, although less active than active regions, is awash with [[w:dynamics (mechanics)|dynamic]] processes and [[w:transient astronomical event|transient]] events (bright points, nanoflares and jets).<ref name=Aschwanden04>{{ cite book | author = M. J. Aschwanden | title = Physics of the Solar Corona. An Introduction | publisher = Praxis Publishing Ltd. | date = 2004 | isbn = 3-540-22321-5 }}</ref> As a general rule, the quiet Sun exists in regions of closed magnetic structures, and active regions are highly dynamic sources of explosive events. It is important to note that observations suggest the whole corona is massively populated by open and closed magnetic fieldlines. A closed fieldline does not constitute a coronal loop; however, closed flux must be ''filled with plasma'' before it can be called a coronal loop. The image at right shows particle rays leaving the surface of the Sun (darker ends of the loops), traveling in a loop controlled by a local magnetic field similar to how particle accelerators accelerate, steer, and aim a stream of particles at a target (the much brighter regions in the chromosphere). The loops have a temperature of approximately 10⁶ K and are emitting X-rays (synchrotron and cyclotron radiation). Coronal loops form the basic structure of the lower corona andtransition region of the Sun. These highly structured and elegant loops are a direct consequence of the twisted solar magnetic flux within the solar body. The population of coronal loops can be directly linked with the solar cycle; it is for this reason coronal loops are often found with sunspots at their footpoints. The upwelling magnetic flux pushes through the photosphere, exposing the cooler plasma below. Loops of magnetic flux (closed flux tubes) well up from the solar body and fill with hot solar plasma.<ref name=Katsukawa>{{ cite journal |author=Yukio Katsukawa |author2=Saku Tsuneta |title=Magnetic Properties at Footpoints of Hot and Cool Loops |journal=The Astrophysical Journal |month=March |year=2005 |volume=621 |issue=1 |pages=498-511 |url=http://iopscience.iop.org/0004-637X/621/1/498/pdf/0004-637X_621_1_498.pdf |arxiv= |bibcode=2005ApJ...621..498K |doi=10.1086/427488 |pmid= |accessdate=2011-12-09 }}</ref> Due to the heightened magnetic activity in these coronal loop regions, coronal loops can often be the precursor to solar flares and coronal mass ejections (CMEs). {{clear}} ==Coronal mass ejections== {{main|Radiation/Meteors}} [[Image:Coronal Mass Ejection.gif|thumb|right|250px|Arcs rise above an active region on the surface of the Sun in this series of images taken by the STEREO (Behind) spacecraft. Credit: Images courtesy of the NASA STEREO Science Center.{{tlx|free media}}]] '''Def.''' a "massive burst of solar wind, other light isotope plasma, and magnetic fields rising above the solar corona or being released into space"<ref name=CoronalMassEjectionWikt>{{ cite book |title=coronal mass ejection |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=June 21, 2013 |url=http://en.wiktionary.org/wiki/coronal_mass_ejection |accessdate=2013-07-07 }}</ref> is called a '''coronal mass ejection''' (CME). An explosive limb flare occurred above 30,000 km in the corona of the [[Sun (star)|Sun]].<ref name=Zirin/> "So the aftermath of the flare explosion, usually visible in disk pictures as extensive Hα brightening, but hidden from us in this case, was seen by the ionosphere as an intense flux of ionizing radiation from the coronal cloud created by the explosion."<ref name=Zirin>{{ cite journal |author=Harold Zirin |title=The Limb Flare of November 20, 1960: a Coronal Phenomenon |journal=Astrophysical Journal |month=October |year=1964 |volume=140 |issue=10 |pages=1216-35 |url= |bibcode=1964ApJ...140.1216Z |doi=10.1086/148019 |pmid= |accessdate=2011-08-01 }}</ref> "The November 20, 1960, event is very similar to that of February 10, 1956, which was observed at Sacramento Peak. A bright ball appears above the surface, grows in size and Hα brightness, and explodes upward and outward."<ref name=Zirin/> "The great breadth and intensity of the Hα emission from the suspended ball at 2013 U.T. testify to the large amount of energy stored there, as no corresponding macroscopic motion was observed until the explosion at 2023 U.T."<ref name=Zirin/> "[T]he great energy of the preflare cloud was released into the corona by the explosion of 2023 U.T., and Hα radiation disappeared by 2035 U.T."<ref name=Zirin/> "On 16 June 1972, the [[w:Naval Research Laboratory|Naval Research Laboratory]]'s coronagraph aboard [[w:OSO-7|OSO-7]] tracked a huge coronal cloud moving outward from the [[Sun (star)|Sun]]."<ref name=Koomen>{{ cite journal |author=Martin Koomen |author2=Russell Howard |author3=Richard Hansen |author4=Shirley Hansen |title=The coronal transient of 16 June 1972 |journal=Solar Physics |month=February |year=1974 |volume=34 |issue=2 |pages=447-52 |url=http://link.springer.com/article/10.1007/BF00153680 |arxiv= |bibcode= |doi=10.1007/BF00153680 |pmid= |accessdate=2013-07-10 }}</ref> A [[w:coronal mass ejection|coronal mass ejection]] (CME) is an ejected plasma consisting primarily of electrons and [[w:proton|proton]]s (in addition to small quantities of heavier elements such as helium, oxygen, and iron), plus the entraining coronal closed magnetic field regions. Evolution of these closed magnetic structures in response to various photospheric motions over different time scales (convection, differential rotation, meridional circulation) somehow leads to the CME.<ref name=Gopalswamy>{{ cite journal |author=Gopalswamy N |author2=Mikic Z |author3=Maia D |author4=Alexander D |author5=Cremades H |author6=Kaufmann P |author7=Tripathi D |author8=Wang YM |title=The pre-CME Sun |journal=Space Sci Rev |year=2006 |volume=123 |issue=1–3 |page=303 |doi=10.1007/s11214-006-9020-2 |bibcode = 2006SSRv..123..303G }}</ref> Small-scale energetic signatures such as plasma heating (observed as compact soft X-ray brightening) may be indicative of impending CMEs. The soft X-ray sigmoid (an S-shaped intensity of soft X-rays) is an observational manifestation of the connection between coronal structure and CME production.<ref name=Gopalswamy/> "Relating the sigmoids at X-ray (and other) wavelengths to magnetic structures and current systems in the solar atmosphere is the key to understanding their relationship to CMEs."<ref name=Gopalswamy/> {{clear}} ==Coronal streamers== The '''interconnections of active regions''' are arcs connecting zones of opposite magnetic field, in different active regions. Significant variations of these structures are often seen after a flare. Some other features of this kind are [[w:helmet streamer|helmet streamer]]s—large cap-like coronal structures with long pointed peaks that usually overlie sunspots and active regions. Coronal streamers are considered as sources of the slow [[w:solar wind|solar wind]].<ref name=Ofman>{{ cite journal | doi= 10.1029/2000GL000097 | last= Ofman | first= Leon | title= Source regions of the slow solar wind in coronal streamers | journal= Geophysical Research Letters | volume = 27 | issue= 18 | pages= 2885–8 |year=2000 | bibcode=2000GeoRL..27.2885O }}</ref> ==Dynamos== "A plasma with local magnetohydrodynamic instabilities creates mechanical turbulence, motion, or shear (a dynamo) which in turn generates or sustains the local magnetic field."<ref name=RadiativeDynamo>{{ cite web |title=Radiative dynamo |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=June 30, 2012 |url=http://en.wikiversity.org/wiki/Radiative_dynamo |accessdate=2012-07-06 }}</ref> ==Electromagnetics== {{main|Radiation astronomy/Electromagnetics}} "The first systematic attempt to base a theory of the origin of the solar system on electromagnetic or hydromagnetic effects was made in Alfvén (1942). The reason for doing so was that a basic difficulty with the old Laplacian hypothesis: how can a central body (Sun or planet) transfer angular momentum to the secondary bodies (planets or satellites) orbiting around it? It was demonstrated that this could be done by electromagnetic effects. No other acceptable mechanism has yet been worked out. [...] the electromagnetic transfer mechanism has been confirmed by observations, as described in the monograph ''Cosmic Plasma'' (Alfvén, 1981, pp. 28, 52, 53 0."<ref name=Alfven1981>{{ cite journal |author=Hannes Alfvén |title=The Voyager 1/Saturn Encounter and the Cosmogonic Shadow Effect |journal=Astrophysics and Space Science |month=October |year=1981 |volume=79 |issue=2 |pages=491-505 |url=http://adsabs.harvard.edu/abs/1981Ap&SS..79..491A |arxiv= |bibcode=1981Ap&SS..79..491A |doi=10.1007/BF00649444 |pmid= |accessdate=2013-12-19 }}</ref> "If charged particles (electrons, ions or charged grains) move in a magnetic dipole field - strong enough to dominate their motion - under the action of gravitation and the centrifugal force, they will find an equilibrium in a circular orbit if their centrifugal force is 2/3 of the gravitational force [...] The consequence of this is that if they become neutralized, so that electromagnetic forces disappear, the centrifugal force is too small to balance the gravitation. Their circular orbit changes to an elliptical orbit with the semi-major axis ''a'' = 3/4''a''₀ and ''e'' = 1/3 (where ''a''₀ is the central distance where the neutralization takes place [...] Collisional (viscous) interaction between the condensed particles will eventually change the orbit into a new circular orbit with ''a'' = 2/3''a''₀ and ''e'' = 0."<ref name=Alfven1981/> "If [...] there is plasma in the region [collisional interaction results in] matter in the 2/3-[region]. [...] matter in the region [...] will produce a [cosmogonic] ''shadow'' in the region".<ref name=Alfven1981/> ==Electron winds== As of December 5, 2011, "Voyager 1 is about ... 18 billion kilometers ... from the [S]un [but] the direction of the magnetic field lines has not changed, indicating Voyager is still within the heliosphere ... the outward speed of the solar wind had diminished to zero in April 2010 ... inward pressure from interstellar space is compacting [the magnetic field] ... Voyager has detected a 100-fold increase in the intensity of high-energy electrons from elsewhere in the galaxy diffusing into our solar system from outside ... [while] the [solar] wind even blows back at us."<ref name=Cole>{{ cite web |author=Steve Cole |author2=Jia-Rui C. Cook |author3=Alan Buis |title=NASA's Voyager Hits New Region at Solar System Edge |publisher=NASA |location=Washington, DC |date=December 2011 |url=http://www.nasa.gov/home/hqnews/2011/dec/HQ_11-402_AGU_Voyager.html |accessdate=2012-02-09 }}</ref> ==Flares== [[Image:06 Major Solar Flare (2820012601).jpg|thumb|right|250px|The solar flare shown in this image was captured on December 13, 2006. Credit: [https://www.flickr.com/people/11304375@N07 Image Editor].{{tlx|free media}}]] "[A] medium-strength flare erupted from the sun on July 19, 2012. The blast also generated the enormous, shimmering plasma loops, which are an example of a phenomenon known as "coronal rain," agency officials said."<ref name=WallRain>{{ cite book |author=Mike Wall |title=Super-Hot Plasma 'Rain' Falls on Sun in Amazing Video |publisher=Yahoo! News |location= |date=February 21, 2013 |url=http://news.yahoo.com/super-hot-plasma-rain-falls-sun-amazing-video-190147271.html |accessdate=2013-02-23 }}</ref> "The ... solar proton flare on 20 April 1998 at W 90° and S 43° (9:38 UT) was measured by the GOES-9-satellite (Solar Geophysical Data 1998), as well as by other experiments on WIND ... and GEOTAIL. Protons were accelerated up to energies > 110 MeV and are therefore able to hit the surface of Mercury."<ref name="Kirsch">{{cite book |author=E. Kirsch |author2=U.A. Mall |author3=B. Wilken |author4=G. Gloeckler |author5=A.B. Galvin |author6=K. Cierpka |title=Detection of Pickup- and Sputter Ions by Experiment SMS on the WIND-S/C After a Mercury Conjunction, In: ''Proceedings of the 26th International Cosmic Ray Conference'' |publisher=International Union of Pure and Applied Physics (IUPAP) |location=Salt Lake City, Utah, USA |date=August 17, 1999 |editor=D. Kieda |editor2=M. Salamon |editor3=B. Dingus |pages=212-5 |url= |arxiv= |bibcode=1999ICRC....6..212K |doi= |pmid= |isbn= }}</ref> Hinode's Solar Optical Telescope (SOT) provides crystal-clear images of features on the sun's surface. This image on the right shows a whirl of a new developing sunspot colliding with an existing spot that explodes into a major solar flare. The solar flare shown was captured on December 13, 2006. The flare produced high-energy protons that reached the Earth at the time of STS-116 Space Shuttle flight. The flare is shown in 3 different wavelengths. {{clear}} ==Flare stars== "Flare stars are intrinsically faint, but have been found to distances of 1,000 [[w:light year|light year]]s from Earth.<ref name=Kulkarni>{{ cite journal |author=Kulkarni SR, Rau A |year=2006 |bibcode=2006ApJ...644L..63K |title=The Nature of the Deep Lens Survey Fast Transients |journal=The Astrophysical Journal |doi=10.1086/505423 |volume=644 |issue=1 |pages=L63 |arxiv = astro-ph/0604343 }}</ref> ==Galactic coronas== Although a galactic corona is usually "filled with high-temperature plasma at temperatures of T ≈ 1–2 (MK), ... [h]ot active regions and postflare loops have plasma temperatures of T ≈ 2–40 MK."<ref name=Aschwanden2007>{{ cite journal |author=Markus J. Aschwanden |title=Fundamental Physical Processes in Coronae: Waves, Turbulence, Reconnection, and Particle Acceleration In: ''Waves & Oscillations in the Solar Atmosphere: Heating and Magneto-Seismology'' |journal=Proceedings IAU Symposium |year=2007 |editor=Erdelyi R |volume=3 |issue= S247 |pages=257–68 |arxiv=0711.0007 |url=http://journals.cambridge.org/download.php?file=%2FIAU%2FIAU3_S247%2FS1743921308014956a.pdf&code=7c95b408db74ccbe9f1f376d4cb1ef35 |doi=10.1017/S1743921308014956 }}</ref> "Discussion of the alternative hypothesis of cloud ejection from the equatorial layer of the Galaxy leads to the conclusion that the gaseous halo must be highly turbulent and that the coronal clouds are probably [[w:H I region|H I region]]s".<ref name=Grzedzielski>{{ cite journal |author=Grzędzielski, S. |author2=Stępień, K. |title=On the Cloudy Structure of the Galactic Gaseous Corona |journal=Acta Astronomica |year=1963 |volume=13 |issue= |pages=143-56 |url= |bibcode=1963AcA....13..143G |doi= |pmid= |accessdate=2011-08-01 }}</ref> "One question posed by these previous observations is where the absorption originates. If a coronal cloud, the cloud is more than 15 kpc from the plane of NGC 3067. This distance is greater than the optical radius of the galaxy, 9.6 kpc (''H'' = 50 km s^-1 Mpc^-1. Furthermore, the narrow line requires that the cloud be cool, in contrast to the wide range of ionization stages detected for the corona of our Galaxy (Savage and deBoer 1981)."<ref name=Rubin>{{ cite journal |author=Rubin V. C. |author2=Thonnard N. T. |author3=Ford W. K. Jr. |title=NGC 3067 - Additional evidence for nonluminous matter |journal=Astronomical Journal |month=March |year=1982 |volume=87 |issue=3 |pages=477-85 |url= |bibcode=1982AJ.....87..477R |doi=10.1086/113120 |pmid= |accessdate=2011-08-01 }}</ref> "But if the cloud originates instead in the disk, and is moving in a circular orbit viewed at an inclination of 68 deg (the inclination of the optical galaxy), then some gas extends at least to 40 kpc, which is over four times the optical radius."<ref name=Rubin/> ==Helmet streamers== [[Image:Helmet streamers at max.gif|thumb|right|250px|An abundance of helmet streamers is shown at solar maximum. Credit: NASA.]] [[Image:Helmet streamers at min.jpg|thumb|left|250px|Helmet streamers are shown at solar minimum restricted to mid latitudes. Credit: NASA.]] '''Helmet streamers''' are bright loop-like structures which develop over active regions on the [[Stars/Sun|sun]]. They are closed magnetic loops which connect regions of opposite magnetic polarity. Electrons are captured in these loops, and cause them to glow very brightly. The solar wind elongates these loops to pointy tips. They far extend above most prominences into the [[Coronal cloud|corona]], and can be readily observed during a solar eclipse. Helmet streamers are usually confined to the "streamer belt" in the mid latitudes, and their distribution follows the movement of active regions during the [[w:solar cycle|solar cycle]]. Small blobs of plasma, or "plasmoids" are sometimes released from the tips of helmet streamers, and this is one source of the slow component of the [[w:solar wind|solar wind]]. In contrast, formations with open magnetic field lines are called [[w:coronal holes|coronal holes]], and these are darker and are a source of the fast solar wind. Helmet streamers can also create coronal mass ejections if a large volume of plasma becomes disconnected near the tip of the streamer. {{clear}} ==Ionospheres== [[Image:Ionosphere-Thermosphere Processes.jpg|thumb|right|250px|In this diagram, the prominent features in the ionosphere-thermosphere system and their coupling to the different energy inputs show the complex temporal and spatial phenomena that are generated. Credit: NASA.]] Upon reaching the top of the [[w:Mesosphere|mesosphere]], the temperature starts to rise, but air pressure continues to fall. This is the beginning of the [[w:ionosphere|ionosphere]], a region dominated by chemical ions. Many of them are the same chemicals such as [[w:nitrogen|nitrogen]] and [[w:oxygen|oxygen]] in the atmosphere below, but an ever increasing number are hydrogen ions ([[w:proton|proton]]s) and helium ions. These can be detected by an ion spectrometer. The process of [[w:ionization|ionization]] removes one or more [[w:electron|electron]]s from a neutral atom to yield a variety of ions depending on the chemical element species and incidence of sufficient energy to remove the electrons. '''Def.''' the "part of the Earth's atmosphere beginning at an altitude of about 50 kilometers [31 miles] and extending outward 500 kilometers [310 miles] or more"<ref name=IonosphereWikt>{{ cite web |author=[[wikt:User:CORNELIUSSEON|CORNELIUSSEON]] |title=ionosphere |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=11 June 2006 |url=https://en.wiktionary.org/wiki/ionosphere |accessdate=2012-09-20 }}</ref> or the "similar region of the atmosphere of another planet"<ref name=IonosphereWikt1>{{ cite web |author=[[wikt:User:RJFJR|RJFJR]] |title=ionosphere |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=15 November 2008 |url=https://en.wiktionary.org/wiki/ionosphere |accessdate=2012-09-20 }}</ref> is called an '''ionosphere'''. "As a spacecraft travels through the solar system, a targeted radio signal sent back to Earth can be aimed through the ionosphere of a nearby planet. Plasma in the ionosphere causes small but detectable changes in the signal that allow scientists to learn about the upper atmosphere."<ref name=Redd>{{ cite web |author=Nola Taylor Redd |title=Meteoroids Change Atmospheres of Earth, Mars, Venus |publisher=Space.com |location= |date=September 4, 2012 |url=http://www.space.com/17440-meteoroids-mars-venus-atmospheres.html |accessdate=2012-09-05 }}</ref> {{clear}} ==Io plasma torus== {{main|Plasmas/Plasma objects/Io}} [[Image:Jupiter magnetosphere schematic.jpg|thumb|right|250px|This is a schematic of Jupiter's magnetosphere and the components influenced by Io (near the center of the image). Credit: John Spencer.]] The image at right represents "[t]he Jovian magnetosphere [magnetic field lines in blue], including the Io flux tube [in green], Jovian aurorae, the sodium cloud [in yellow], and sulfur torus [in red]."<ref name=Spencer>{{ cite book |author=John Spencer |title=John Spencer's Astronomical Visualizations |publisher=University of Colorado |location=Boulder, Colorado USA |date=November 2000 |url=http://www.boulder.swri.edu/~spencer/digipics.html |accessdate=2013-04-05 }}</ref> "Io may be considered to be a unipolar generator which develops an emf [electromotive force] of 7 x 10⁵ volts across its radial diameter (as seen from a coordinate frame fixed to Jupiter)."<ref name=Goldreich>{{ cite journal |author=Peter Goldreich |author2=Donald Lynden-Bell |title=Io, a jovian unipolar inductor |journal=The Astrophysical Journal |month=April |year=1969 |volume=156 |issue=04 |pages=59-78 |url= |arxiv= |bibcode=1969ApJ...156...59G |doi=10.1086/149947 |pmid= |accessdate=2013-04-05 }}</ref> "This voltage difference is transmitted along the magnetic flux tube which passes through Io. ... The current [in the flux tube] must be carried by keV electrons which are electrostatically accelerated at Io and at the top of Jupiter's ionosphere."<ref name=Goldreich/> "Io's high density (4.1 g cm^-3) suggests a silicate composition. A reasonable guess for its electrical conductivity might be the conductivity of the Earth's upper mantle, 5 x 10^-5 ohm^-1 cm^-1 (Bullard 1967)."<ref name=Goldreich/> As "a conducting body [transverses] a magnetic field [it] produces an induced electric field. ... The Jupiter-Io system ... operates as a unipolar inductor" ... Such unipolar inductors may be driven by electrical power, develop hotspots, and the "source of heating [may be] sufficient to account for the observed X-ray luminosity".<ref name=Wu>{{ cite journal |author=Kinwah Wu |author2=Mark Cropper |author3=Gavin Ramsay |author4=Kazuhiro Sekiguchi |title=An electrically powered binary star? |journal=Monthly Notices of the Royal Astronomical Society |month=March |year=2002 |volume=321 |issue=1 |pages=221-7 |url= |arxiv=astro-ph/0111358 |bibcode=2002MNRAS.331..221W |doi=10.1046/j.1365-8711.2002.05190.x |pmid= |accessdate=2013-04-05 }}</ref> "The electrical surroundings of Io provide another energy source which has been estimated to be comparable with that of the [gravitational] tides (7). A current of 5 x 10⁶ A is ... shunted across flux tubes of the Jovian field by the presence of Io (7-9)."<ref name=Gold>{{ cite journal |author=Thomas Gold |title=Electrical Origin of the Outbursts on Io |journal=Science |month=November |year=1979 |volume=206 |issue=4422 |pages=1071-3 |url= |arxiv= |bibcode=1979Sci...206.1071G |doi=10.1126/science.206.4422.1071 |pmid= |accessdate=2013-04-05 }}</ref> "[W]hen the currents [through Io] are large enough to cause ohmic heating ... currents ... contract down to narrow paths which can be kept hot, and along which the conductivity is high. Tidal heating [ensures] that the interior of Io has a very low eletrical resistance, causing a negligible extra amount of heat to be deposited by this current. ... [T]he outermost layers, kept cool by radiation into space [present] a large resistance and [result in] a concentration of the current into hotspots ... rock resistivity [and] contact resistance ... contribute to generate high temperatures on the surface. [These are the] conditions of electric arcs [that can produce] temperatures up to ionization levels ... several thousand kelvins".<ref name=Gold/> "[T]he outbursts ... seen [on the surface may also be] the result of the large current ... flowing in and out of the domain of Io ... Most current spots are likely to be volcanic calderas, either provided by tectonic events within Io or generated by the current heating itself. ... [A]s in any electric arc, very high temperatures are generated, and the locally evaporated materials ... are ... turned into gas hot enough to expand at a speed of 1 km/s."<ref name=Gold/> {{clear}} ==Local hot bubbles== [[Image:Local_bubble.jpg|thumb|right|250px|The Local Hot Bubble is hot X-ray emitting gas within the Local Bubble pictured as an artist's impression. Credit: NASA.]] The 'local hot bubble' is a "hot X-ray emitting plasma within the local environment of the Sun."<ref name=Kappes>{{ cite journal |author=M. Kappes |author2=J. Kerp |author3=P. Richter |title=The composition of the interstellar medium towards the Lockman Hole H I, UV and X-ray observations |journal=Astronomy and Astrophysics |month=July |year=2003 |volume=405 |issue=7 |pages=607-16 |url= |arxiv= |bibcode=2003A&A...405..607K |doi=10.1051/0004-6361:20030610 |pmid= |accessdate=2012-01-19 }}</ref> "This coronal gas fills the irregularly shaped local void of matter (McCammon & Sanders 1990) - frequently called the Local Hot Bubble (LHB)."<ref name=Kappes/> "The [X-ray] intensity of the [Local Hot Bubble] LHB varies across the entire sky:"<ref name=Kerp>{{ cite journal |author=J. Kerp |author2=W. B. Burton |author3=R. Egger |author4=M.J. Freyberg |author5=Dap Hartmann |author6=P.M.W. Kalberla |author7=U. Mebold |author8=J. Pietz |title=A search for soft X-ray emission associated with prominent high-velocity-cloud complexes |journal=Astronomy and Astrophysics |month=February |year=1999 |volume=342 |issue=02 |pages=213-32 |url=http://arxiv.org/abs/astro-ph/9810307 |arxiv=astro-ph/9810307 |bibcode=1999A&A...342..213K |doi= |pmid= |accessdate=2013-07-11 }}</ref> : ''I''_LHB = (2.5-8.2) x 10^-4 cts s^-1 arcmin^-2 (Snowden et al. 1998). The galactic X-ray background is produced largely by emission from the Local Hot Bubble which is within 100 parsecs of the Sun. The Local Hot Bubble is within the [[w:Local Bubble|Local Bubble]]. {{clear}} ==Magnetic clouds== A '''magnetic cloud''' is a transient event observed in the [[w:solar wind|solar wind]]. It was defined in 1981 by Burlaga et al. 1981 as a region of enhanced [[w:magnetic field|magnetic field]] strength, smooth rotation of the magnetic field vector and low [[w:proton|proton]] temperature <ref name=Burlaga>Burlaga, L. F., E. Sittler, F. Mariani, and R. Schwenn, "Magnetic loop behind an interplanetary shock: Voyager, Helios and IMP-8 observations" in "Journal of Geophysical Research", 86, 6673, 1981</ref>. Magnetic clouds are a possible manifestation of a [[w:Coronal Mass Ejection|Coronal Mass Ejection]] (CME). The association between CMEs and magnetic clouds was made by Burlaga et al. in 1982 when a magnetic cloud was observed by [[w:Helios probes|Helios-1]] two days after being observed by [[w:Solar Maximum Mission|SMM]]<ref name=Burlaga82>Burlaga, L. F. et al., "A magnetic cloud and a coronal mass ejection" in "Geophysical Research Letter"s, 9, 1317-1320, 1982</ref>. However, because observations near Earth are usually done by a single spacecraft, many CMEs are not seen as being associated with magnetic clouds. The typical structure observed for a fast CME by a satellite such as [[w:Advanced Composition Explorer|ACE]] is a fast-mode [[w:shock wave|shock wave]] followed by a dense (and hot) sheath of plasma (the downstream region of the shock) and a magnetic cloud. Other signatures of magnetic clouds are now used in addition to the one described above: among other, bidirectional superthermal electrons, unusual charge state or abundance of iron, helium, carbon and/or oxygen. The typical time for a magnetic cloud to move past a satellite at the [[w:Lagrange Point|L1]] point is 1 day corresponding to a radius of 0.15 [[w:Astronomical Unit|AU]] with a typical speed of 450&nbsp;km s⁻¹ and magnetic field strength of 20 nT <ref name=Lepping>Lepping, R. P. et al. "Magnetic field structure of interplanetary magnetic clouds at 1 AU" in "Journal of Geophysical Research", 95, 11957-11965, 1990.</ref> ==Magnetic reconnections== Magnetic reconnection is a physical process in highly conducting plasmas in which the magnetic [[w:topology|topology]] is rearranged and magnetic energy is converted to [[w:kinetic energy|kinetic energy]], [[w:thermal energy|thermal energy]], and [[w:particle acceleration|particle acceleration]]. Magnetic reconnection occurs on timescales intermediate between slow resistive diffusion of the [[w:magnetic field|magnetic field]] and fast [[w:Alfven wave|Alfvénic]] timescales. The qualitative description of the reconnection process is such that magnetic field lines from different [[w:magnetic domain|magnetic domain]]s (defined by the field line connectivity) are spliced to one another, changing their patterns of connectivity with respect to the sources. It is a violation of an approximate conservation law in plasma physics, and can concentrate mechanical or magnetic energy in both space and time. ==Magnetospheres== A '''magnetosphere''' is formed when a stream of charged particles, such as the solar wind, interacts with and is deflected by the magnetic field of a planet or similar body. “Planets which generate magnetic fields in their interiors ... are surrounded by invisible magnetospheres. ... [I]n many respects, the magnetosphere of Venus is a scaled-down version of Earth’s. ... Earth’s magnetosphere is 10 times larger [than that of Venus]”<ref name=Zhang>{{ cite book |author=Tielong Zhang |author2=Håkan Svedhem |title=A magnetic surprise for Venus Express |publisher=European Space Agency |location=The Netherlands |date=April 5, 2012 |url=http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=50246 |accessdate=2012-04-07 }}</ref> ==Microflares== Ultraviolet telescopes such as [[w:TRACE|TRACE]] and [[w:Solar and Heliospheric Observatory|SOHO]]/EIT can observe individual [solar] micro-flares as small brightenings in extreme ultraviolet light.<ref name=Patsourakos>{{ cite journal | doi = 10.1051/0004-6361:20020151 | author =S. Patsourakos, J.-C. Vial | title = Intermittent behavior in the transition region and the low corona of the quiet Sun | journal = Astronomy and Astrophysics | volume = 385 | pages = 1073–1077 | year = 2002 | bibcode=2002A&A...385.1073P }}</ref> ==Nanoflares== [[Image:378877main Nanoflares lg.jpg|thumb|right|250px|"This false-color temperature map shows solar active region AR10923, observed close to center of the sun's disk. Blue regions indicate plasma near 10 million degrees K." Credit: Reale, et al. (2009), NASA.]] The image at the right shows the first detection of high temperature nanoflares. The false-color temperature map of solar active region AR10923, observed close to center of the sun's disk, contains nanoflare regions (blue, indicating plasma near 10 million degrees K). "Nanoflares are small, sudden bursts of heat and energy. "They occur within tiny strands that are bundled together to form a magnetic tube called a coronal loop," says Klimchuk. Coronal loops are the fundamental building blocks of the thin, translucent gas known as the sun's [[Coronal cloud|corona]]. ... Observations from the NASA-funded X-Ray Telescope (XRT) and Extreme-ultraviolet Imaging Spectrometer (EIS) instruments aboard Hinode reveal that ultra-hot plasma is widespread in solar active regions. The XRT measured plasma at 10 million degrees K, and the EIS measured plasma at 5 million degrees K. "These temperatures can only be produced by impulsive energy bursts,"says Klimchuk ... "Coronal loops are bundles of unresolved strands that are heated by storms of nanoflares." ... when a nanoflare suddenly releases its energy, the plasma in the low-temperature, low-density strands becomes very hot—around 10 million degrees K—very quickly. The density remains low, however, so the emission, or brightness, remains faint. Heat flows from up in the strand, where it's hot, down to the base of the coronal loop, where it's not as hot. This heats up the dense plasma at the loop’s base. Because it is so dense at the base, the temperature only reaches about 1 million degrees K. This dense plasma expands up into the strand. Thus, a coronal loop is a collection of 5-10 million degree K faint strands and 1 million degree K bright strands. "What we see is 1 million degree K plasma that has received its energy from the heat flowing down from the superhot plasma," says Klimchuk. "For the first time, we have detected this 10 million degree plasma, which can only be produced by the impulsive energy bursts of nanoflares.""<ref name=Layton2009>{{ cite web |author=Laura Layton |title=Tiny Flares Responsible for Outsized Heat of Sun's Atmosphere |publisher=NASA GSFC |location=Greenbelt, Maryland, USA |date=August 14, 2009 |url=http://www.nasa.gov/topics/solarsystem/features/nanoflares.html |accessdate=2012-11-18 }}</ref> The idea that nanoflares might heat the corona was put forward by [[w:Eugene Parker|Eugene Parker]] in the 1980s but is still controversial. In particular, ultraviolet telescopes such as [[w:TRACE|TRACE]] and [[w:Solar and Heliospheric Observatory|SOHO]]/EIT can observe individual micro-flares as small brightenings in extreme ultraviolet light,<ref name=Patsourakos/> but there seem to be too few of these small events to account for the energy released into the corona. The additional energy not accounted for could be made up by wave energy, or by gradual magnetic reconnection that releases energy more smoothly than micro-flares and therefore doesn't appear well in the TRACE data. Variations on the micro-flare hypothesis use other mechanisms to stress the magnetic field or to release the energy, and are a subject of active research in 2005. A nanoflare is a very small [[w:solar flare|solar flare]] which happens in the [[w:corona|corona]], the external [[w:atmosphere|atmosphere]] of the [[Stars/Sun|Sun]]. Observations show that the [[w:solar magnetic field|solar magnetic field]], which is frozen into the motion of the [[w:Plasma (physics)|plasma]] opens into semicirculal structures in the corona. These [[w:coronal loops|coronal loops]], which can be seen in the EUV and X-ray images (see the figure on the left), confine very hot plasma, emitting as it were at a temperature of a few million degrees. Many flux tubes are stable for several days on the solar corona in the X-ray images, emitting at steady rate. However flickerings, brightenings, small explosions, bright points, flares and mass eruptions are observed very frequently, especially in [[w:stellar active region|active regions]]. These macroscopic signs of solar activity are considered by astrophysicists as the phenomenology related to events of relaxation of stressed magnetic fields, during which part of the coronal heating is released by current dissipation or [[w:Joule effect|Joule effect]]. These nanoflares might be very tiny flares, so close one to each other, both in time and in space, to heat the corona and to cause all the phenomena due to solar activity. The distribution of the number of flares observed in the hard X-rays is a function of the energy, following a power law with negative spectral index 1.8.<ref name=Datlowe>{{ cite journal | author = D.W. Datlowe |author2=M.J.Elean |author3=H.S. Hudson | title =OSO-7 observations of solar x-rays in the energy range 10?100 keV | journal = Solar Physics | volume = 39 | pages = 155 | year = 1974 | doi = 10.1007/BF00154978 | bibcode=1974SoPh...39..155D }}</ref><ref name=Lin>{{ cite journal |author=Lin R.P. |author2=Schwartz R.A. |author3=Kane S.R. |author4=Pelling R.M. |author5=Hurley K.C. | journal= The Astrophysical Journal | volume= 283 | pages= 421 |doi=10.1086/162321 |title=Solar hard X-ray microflares | bibcode=1984ApJ...283..421L }}</ref><ref name=Dennis>{{ cite journal |author=Brian R. Dennis | year= 1985 | journal= Solar Physics | volume= 100 | pages= 465 |doi=10.1007/BF00158441 |title=Solar hard X-ray bursts | bibcode=1985SoPh..100..465D }}</ref> <ref name=Porter>{{ cite journal | author=Porter J.G. |author2=Fontenla J.M. |author3=Simnett G.M. |journal= The Astrophysical Journal | volume= 438 |pages= 472 | doi=10.1086/175091 | title=Simultaneous ultraviolet and X-ray observations of solar microflares | bibcode=1995ApJ...438..472P }}</ref> If this distribution would have the same spectral index also at lower energies, flares, micro-flares and nanoflares might provide a considerable part of coronal heating. Actually a negative spectral index of the order of 2 is required in order to maintain the [[w:solar corona|solar corona]]. "[T]he importance of the magnetic field is recognized by all the scientists: there is a strict correspondence between the [[w:stellar active region|active regions]], where the irradiated flux is higher (especially in the X-rays), and the regions of intense magnetic field.<ref name=Poletto>{{ cite journal |author=Poletto G |author2=Vaiana GS |author3=Zombeck MV |author4=Krieger AS |author5=Timothy AF |title=A comparison of coronal X-ray structures of active regions with magnetic fields computed from photospheric observations |journal=Solar Physics |date=September 1975 |volume=44 |issue=9 |pages=83–99 |doi=10.1007/BF00156848 |bibcode=1975SoPh...44...83P }}</ref> More energy is released in turbulent regimes when nanoflares happen at much smaller scale-lengths, where non-linear effects are not negligible.<ref name=Rappazzo>{{ cite journal |author= Rappazzo, A. F. |author2=Velli, M. |author3=Einaudi, G. |author4=Dahlburg, R. B. |title=Nonlinear Dynamics of the Parker Scenario for Coronal Heating |journal=The Astrophysical Journal 2008 |volume=677 |issue= 2 |pages= 1348–1366 |bibcode=2008ApJ...677.1348R |doi= 10.1086/528786 }}</ref> In order to heat a region of very high [[w:X-ray|X-ray]] emission, over an area 1" x 1", a nanoflare of 10¹⁷ J should happen every 20 seconds, and 1000 nanoflares per second should occur in a large active region of 10⁵ x 10⁵ km². Flickerings, brightenings, small explosions, bright points, flares and mass eruptions are observed very frequently, especially in [[stellar active region|active regions]]. {{clear}} ==Nova-like stars== {{main|Stars/Nova-likes}} The evolution of non-magnetic dwarf novae and nova-like stars can be different from the magnetic systems (polars and intermediate polars).<ref name=Ak/> Magnetic and non-magnetic systems display different kinematical properties since some flow velocities come from magnetically channeled plasma.<ref name=Ak>{{ cite journal |author=T Ak T |author2=S Bilir |author3=S Ak |author4=KB Coskunoglu |author5=Z Eker |title=The age of cataclysmic variables: a kinematic study |journal=New Astronomy |month=August |year=2010 |volume=15 |issue=6 |pages=491-508 |url=http://adsabs.harvard.edu/abs/2010NewA...15..491A |arxiv=0911.3651 |bibcode=2010NewA...15..491A |doi=10.1016/j.newast.2009.11.007 |pmid= |accessdate=2016-09-30 }}</ref> ==Photospheres== The solar photosphere is a "weakly ionized [''n''_i/(''n''_i + ''n''_a)] ~ 10^-4, relatively cold and dense plasma".<ref name=Khodachenko>{{ cite journal |author=M. L. Khodachenko |author2=V. V. Zaitsev |title=Formation of Intensive Magnetic Flux Tubes in a Converging Flow of Partially Ionized Solar Photospheric Plasma |journal=Astrophysics and Space Science |month=March 01, |year=2002 |volume=279 |issue=4 |pages=389-410 |url=http://link.springer.com/article/10.1023/A:1015162131331 |arxiv= |bibcode= |doi=10.1023/A:1015162131331 |pmid= |accessdate=2013-07-17 }}</ref> ==Plages== A '''plage''' is a bright region in the [[w:chromosphere|chromosphere]] of [a star], typically found in regions of the chromosphere near [starspots]. The plage regions map closely to the [[w:faculae|faculae]] in the photosphere below, but the latter have much smaller spatial scales. Accordingly plage occurs most visibly near a starspot region. "Plages are formed in the inner parts of flux loops emerging from below. ... In the early stages of active region growth the appearance of the group is symmetric, while a few days later the ''f'' spot may disappear, leaving an extensive plage."<ref name=Zirin1974>{{ cite book |author=H. Zirin |title=The Magnetic Structure of Plages, In: ''Chromospheric Fine Structure'' |publisher=International Astronomical Union |location=Dordrecht |year=1974 |editor=R. Grant Athay |pages=161-75 |url= |arxiv= |bibcode=1974IAUS...56..161Z |doi= |pmid= |isbn= }}</ref> "[M]ajor changes in active regions only take place in the following ways: # [starspot] formation and break up; # flux outflow from [starspots]; # new flux emergence; and # magnetic reconnection."<ref name=Zirin1974/> "In general there is no proper motion at all in the plage or the surrounding plagettes except for the latter two."<ref name=Zirin1974/> ==Plasma objects== {{main|Plasmas/Plasma objects|Plasma objects}} '''Plasma''' is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms (reduce or increase the number of electrons in them), thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions.<ref name=Luo>{{ cite journal |author=Q-Z Luo |author2=N. D'Angelo |author3=R. L. Merlino | year=1998 |title=Shock formation in a negative ion plasma |journal= |volume=5 |issue=8 |publisher=Department of Physics and Astronomy |url=http://www.physics.uiowa.edu/~rmerlino/nishocks.pdf |accessdate=2011-11-20}}</ref> For plasma to exist, ionization is necessary. The term "plasma density" by itself usually refers to the "electron density", that is, the number of free electrons per unit volume. The degree of ionization of a plasma is the proportion of atoms that have lost or gained electrons, and is controlled mostly by the temperature. Even a partially ionized gas in which as little as 1% of the particles are ionized can have the characteristics of a plasma (i.e., response to magnetic fields and high electrical conductivity). The degree of ionization, ''α'' is defined as ''α'' = ''n''_i/(''n''_i + ''n''_a) where ''n''_i is the number density of ions and ''n''_a is the number density of neutral atoms. The ''electron density'' is related to this by the average charge state <Z> of the ions through ''n''_e = <Z> ''n''_i where ''n''_e is the number density of electrons. "Plasma is the fourth state of matter, consisting of electrons, ions and neutral atoms, usually at temperatures above 10⁴ degrees Kelvin."<ref name=Birdsall>{{ cite book |author=CK Birdsall, A. Bruce Langdon |title=Plasma Physics via Computer Simulation |publisher=CRC Press |location=New York |date=1 October 2004 |editor= |pages=479 |url=http://books.google.com/books?hl=en&lr=&id=S2lqgDTm6a4C&oi=fnd&pg=PR13&ots=nOPXyqtDo8&sig=-kA8YfaX6nlfFnaW3CYkATh-QPg |arxiv= |bibcode= |doi= |pmid= |isbn=9780750310253 |accessdate=2011-12-17 }}</ref> "The sun and stars are plasmas; the earth's ionosphere, Van Allen belts, magnetosphere, etc., are all plasmas. Indeed, plasma makes up much of the known matter in the universe."<ref name=Birdsall/> ==Plasma rains== "Hot plasma in the corona cooled and condensed along strong magnetic fields in the region" slowly falling back to the solar surface as plasma "rain".<ref name=WallRain/> {{clear}} ==Prominences== [[Image:Sunflare skylab4 big.jpg|thumb|right|250px|A major eruptive prominence is imaged by Skylab in 1973. Credit: [http://www.ksc.nasa.gov/history/skylab/skylab.html Skylab], NASA.]] [[Image:Detached sola prominence.jpg|thumb|right|250px|This shows a detached Solar prominence. Credit: [https://sites.google.com/site/thebrockeninglory/ Brocken Inaglory].]] A '''prominence''' is a large, bright feature extending outward from [a star's] surface, often in a [[w:Coronal loops|loop]] shape. Prominences are anchored to [a star's] surface in the [[w:photosphere|photosphere]], and extend outwards into the [star's] [[Coronal cloud|corona]]. While the corona consists of extremely hot ionized gases, known as [[w:Plasma (physics)|plasma]], which [does] not emit much visible light, prominences contain much cooler plasma, similar in composition to that of the [[w:chromosphere|chromosphere]]. A prominence forms over timescales of about a day, and stable prominences may persist in the corona for several months. Some prominences break apart and give rise to [[w:coronal mass ejection|coronal mass ejection]]s. A typical prominence extends over many thousands of kilometers; the largest on record was estimated at over 800,000 kilometres (500,000 mi) long<ref name="univtoday">{{ cite book |url=http://www.universetoday.com/96649/huge-solar-filament-stretches-across-the-sun/ |title=Huge Solar Filament Stretches Across the Sun |author=Nancy Atkinson |work=Universe Today |date=August 6, 2012 |accessdate=August 11, 2012 }}</ref> – roughly the radius of the Sun. "When a prominence is viewed from a different perspective so that it is against the [star] instead of against space, it appears darker than the surrounding background. This formation is instead called a [stellar] filament.<ref name="univtoday" /> It is possible for a projection to be both a filament and a prominence. Some prominences are so powerful that they throw out matter from the [star] into space at speeds ranging from 600&nbsp;km/s to more than 1000&nbsp;km/s. Other prominences form huge loops or arching columns of glowing gases over [starspots] that can reach heights of hundreds of thousands of kilometres. Prominences may last for a few days or even for a few months.<ref>{{ cite book | url=http://solar.physics.montana.edu/ypop/Program/hfilament.html | title=About Filaments and Prominences | accessdate=2010-01-02 }}</ref> Flocculi (plural of flocculus) is another term for these filaments, and dark flocculi typically describes the appearance of [stellar] prominences when viewed against the [stellar] disk in certain wavelengths. {{clear}} ==Regions== {{main|Regions/Astronomy}} [[Image:LASCO C1 coronagraph of solar corona.png‎|right|thumb|250px|A picture of the solar corona is taken with the [[w:LASCO|LASCO]] C1 coronagraph. The image is color coded for the doppler shift of the FeXIV 530.8 nm line. Credit: NASA and NRL.]] The preflare solar material is observed "to be an elevated cloud of prominence-like material which is suddenly lit up by the onslaught of hard electrons accelerated in the flare; the acceleration may be inside or outside the cloud, and brightening is seen in other areas of the solar surface on the same magnetic field lines."<ref name=Zirin78>{{ cite journal |author=Harold Zirin |title=The L-alpha/H-alpha ratio in solar flares, quasars, and the chromosphere |journal=Astrophysical Journal |month=June |year=1978 |volume=222 |issue=6 |pages=L105-7 |url= |bibcode=1978ApJ...222L.105Z |doi= 10.1086/182702 |pmid= |accessdate=2011-08-01 }}</ref> "A hot coronal cloud at ''T'' ~ 10⁷ K is left behind, presumably evaporated from the original material."<ref name=Zirin78/> "[O]nce ionized, the gas is rapidly heated by Coulomb collisions to the coronal cloud temperature, but as this material peels off, a cooler hydrogen-emitting region is left."<ref name=Zirin78/> Regions which are not in [[w:coronal hole|coronal hole]]s are "called 'coronal cloud' regions after their appearance in photographs of the Sun taken in soft X-rays, which most dramatically show up coronal holes."<ref name=McWhirter>{{ cite journal |author=McWhirter R. W. P. |author2=Kopp R. A. |title=The energy balance in the solar atmosphere above coronal holes |journal=Royal Astronomical Society, Monthly Notices |month=September |year=1979 |volume=188 |issue=9 |pages=871-81 |url= |bibcode=1979MNRAS.188..871M |doi= |pmid= |accessdate=2011-08-01 }}</ref> These 'coronal cloud' regions are "in fact the majority of the solar surface."<ref name=McWhirter/> Lying at a level above the 10⁴ K isotherm, "the thermally conducted flux is negligible, and bounded by the magnetic surfaces between open field (coronal hole) and closed field (coronal cloud) regions."<ref name=McWhirter/> "[C]oronal cloud regions produce no solar wind," but "[s]ome of the input energy may pass out of the cloud regions into the region where the wind is accelerated, thereby contributing to this process."<ref name=McWhirter/> In the image at right the iron (Fe XIV) green line is followed by doppler imaging to show associated relative coronal plasma velocity towards (-7 km/s side) and away from (+7 km/s side) the large angle spectrometric coronagraph [[w:LASCO|LASCO]] satellite camera. {{clear}} ==Starquakes== [[Image:MoretonWaveAnimation200612.gif|thumb|right|250px|This is an animation of a Moreton wave which occurred on the Sun at December 6, 2006. Credit: National Solar Observatory (NSO)/AURA/NSF and USAF Research Laboratory.]] [[Image:Solar tsunami.jpg|thumb|250px|right|This image shows a solar tsunami on May 19, 2007. Credit: NASA/STEREO/EUVI consortium.]] "The phenomenon of flare induced sunquakes - waves in the photosphere - discovered by Kosovichev and Zharkova (1998) and now widely studied (e.g. Kosovichev 2006) should also result from the momentum impulse delivered by a cometary impact."<ref name=Brown>{{ cite journal |author=J.C. Brown |author2=H.E. Potts |author3=L.J. Porter |author4=G.le Chat |title=Mass Loss, Destruction and Detection of Sun-grazing & -impacting Cometary Nuclei |journal=Astronomy & Astrophysics |date=November 8, 2011 |volume=535 |issue= |pages=12 |url=http://www.aanda.org/articles/aa/abs/2011/11/aa15660-10/aa15660-10.html |arxiv= |bibcode= |doi=10.1051/0004-6361/201015660 |pmid= |pdf=http://arxiv.org/pdf/1107.1857.pdf |accessdate=2012-11-25 }}</ref> A '''Moreton wave''' is the [[w:chromosphere|chromospheric]] signature of a large-scale solar [[Coronal cloud|coronal]] [[w:shock wave|shock wave]]. Described as a kind of [[Stars/Sun|solar]] '[[w:tsunami|tsunami]]',<ref name="tphill09">{{ cite book |author=Tony Phillips |title=Monster Waves on the Sun are Real |url=http://science.nasa.gov/science-news/science-at-nasa/2009/24nov_solartsunami/ |publisher=NASA |accessdate=16 July 2010 |date=November 24, 2009 }}</ref> they are generated by solar flares<ref name=Moreton>{{ cite journal |author=G. E. Moreton |title=Hα Observations of Flare-Initiated Disturbances with Velocities ~1000 km/sec |journal=Astronomical Journal |volume=65 |issue= |pages=494 |year=1960 |doi=10.1086/108346 |bibcode=1960AJ.....65U.494M }}</ref><ref name=Moreton60>{{ cite journal |author=G. E. Moreton, H. E. Ramsey |title=Recent Observations of Dynamical Phenomena Associated with Solar Flares |journal=Publications of the Astronomical Society of the Pacific |volume=72 |issue=428 |pages=357 |year=1960 |doi=10.1086/127549 |bibcode=1960PASP...72..357M }}</ref><ref name=Athay61>{{ cite journal |author=R. Grant Athay, Gail E. Moreton |title=Impulsive Phenomena of the Solar Atmosphere. I. Some Optical Events Associated with Flares Showing Explosive Phase |journal=The Astrophysical Journal |year=1961 |volume=133 |issue= |pages=935 |doi=10.1086/147098 |bibcode=1961ApJ...133..935A }}</ref>. The 1995 launch of the [[w:Solar and Heliospheric Observatory|Solar and Heliospheric Observatory]] led to observation of coronal waves, which cause Moreton waves. (SOHO's [[w:Extreme ultraviolet Imaging Telescope|EIT]] instrument discovered another, different wave type called 'EIT waves'.)<ref name=Chen>{{ cite journal |url=http://solar.physics.montana.edu/nuggets/2002/020208/020208.html |title=Moreton waves and coronal waves |journal=The Astrophysical Journal |volume=572 |issue= |pages=L99–L102 |year=2002 |bibcode = 2002ApJ...572L..99C |doi = 10.1086/341486 |author=P. F. Chen |author2=S. T. Wu |author3=K. Shibata |author4=C. Fang }}</ref> The reality of Moreton waves (aka fast-mode [[w:Magnetohydrodynamics|MHD]] waves) has also been confirmed by the two [[w:STEREO|STEREO]] spacecraft. They observed a 100,000-km-high wave of hot plasma and magnetism, moving at 250&nbsp;km/second, in conjunction with a big coronal mass ejection in February 2009.<ref name=Atkins>{{ cite book |author=William Atkins |title=STEREO spacecraft finds gigantic tsunami on Sun |url=http://www.itwire.com/science-news/space/29658-stereo-spacecraft-finds-gigantic-tsunami-on-sun |publisher=iTWire |accessdate=16 July 2010 |date=26 November 2009 }}</ref><ref name="pho111909">{{ cite book |title=Mystery of the Solar Tsunami -- Solved |url=http://www.physorg.com/news177872248.html |publisher=PhysOrg.com |accessdate=16 July 2010 |author=JPL/NASA |date=November 19, 2009 }}</ref> Moreton waves propagate at a speed of usually 500–1500&nbsp;km/s. [[w:Yutaka Uchida|Yutaka Uchida]] interpreted Moreton waves as MHD fast mode shock waves propagating in the corona.<ref name=Sakurai2002>{{ cite book |author=Takashi Sakurai |title=SolarNews Newsletter |url=http://spd.aas.org/SolarNews/archive/news.2002/19.sep |publisher=Solar Physics Division, American Astronomical Society |accessdate=15 June 2011 |date=3 September 2002 }}</ref> He links them to [[w:type II radio bursts|type II radio bursts]], which are radio wave discharges created when coronal mass ejections accelerate shocks.<ref name=Layton>{{ cite book |author=Laura Layton |title=STEREO Spies First Major Activity of Solar Cycle 24 |url=http://www.nasa.gov/mission_pages/stereo/news/solarcycle24.html |publisher=NASA |accessdate=15 June 2011 |date=May 15, 2009 }}</ref> Moreton waves can be observed primarily in the [[w:Hα|Hα]] band.<ref name="Narukage, et al.">{{ cite journal |author=N. Narukage |author2=Shigeru |author3=Miwako Kadota |author4=Reizaburo Kitai |author5=Hiroki Kurokawa |author6=Kazunari Shibata |year=2004 |title=Moreton waves observed at Hida Observatory |journal = Proceedings IAU Symposium |issue = 223 |pages = 367–370 |doi=10.1017/S1743921304006143 |url=http://journals.cambridge.org/production/action/cjoGetFulltext?fulltextid=288483 |accessdate = 2006-12-11 |volume = 2004 }}</ref> {{clear}} ==Stellar cycles== [[Image:Sunspot_butterfly_graph.gif|thumb|200px|right|The [[w:Butterfly diagram|butterfly diagam]] shows paired sunspot pattern. The graph is of sunspot [[w:Wolf number|Wolf number]] versus time. Credit: .]] The solar cycle has a great influence on [[w:space weather|space weather]], and a significant influence on the Earth's climate since the Sun's luminosity has a direct relationship with magnetic activity.<ref name=Wilson>{{ cite journal |author=R. C. Willson, H. S. Hudson |year=1991 |title=The Sun's luminosity over a complete solar cycle |journal=Nature |volume=351 |issue=6321 |pages=42–4 |doi=10.1038/351042a0 |bibcode = 1991Natur.351...42W }}</ref> Solar activity minima tend to be correlated with colder temperatures, and longer than average solar cycles tend to be correlated with hotter temperatures. In the 17th century, the solar cycle appeared to have stopped entirely for several decades; few sunspots were observed during this period. During this era, known as the [[w:Maunder minimum|Maunder minimum]] or [[w:Little Ice Age|Little Ice Age]], Europe experienced unusually cold temperatures.<ref name="Lean">{{ cite journal |last=Lean |first=J. |last2=Skumanich |first2=A. |last3=White |first3=O. |year=1992 |title=Estimating the Sun's radiative output during the Maunder Minimum |journal=Geophysical Research Letters |volume=19 |issue=15 |pages=1591–1594 |doi=10.1029/92GL01578 |ref=harv |bibcode=1992GeoRL..19.1591L }}</ref> Earlier extended minima have been discovered through analysis of [[w:tree ring|tree ring]]s and appear to have coincided with lower-than-average global temperatures.<ref name=Mackay>{{ cite book |author=R. M. Mackay, M. A. K. Khalil |title=Greenhouse gases and global warming, In: ''Trace Gas Emissions and Plants'' |url= http://books.google.com/?id=tQBS3bAX8fUC&pg=PA1 |editor=S. N. Singh |year=2000 |pages=1–28 |publisher=Springer |isbn=978-0-7923-6545-7 }}</ref> "MOST current literature on solar activity assumes that the planets do not affect it, and that conditions internal to the Sun are primarily responsible for the solar cycle. Bigg¹, however, has shown that the period of Mercury's orbit appears in the sunspot data, and that the influence of Mercury depends on the phases of Venus, Earth, and Jupiter."<ref name=Wood>{{ cite journal |author=K. D. Wood |title=Physical Sciences: Sunspots and Planets |journal=Nature |month=November 10, |year=1972 |volume=240 |issue=5376 |pages=91-3 |url=http://www.nature.com/nature/journal/v240/n5376/abs/240091a0.html |arxiv= |bibcode=1972Natur.240...91W |doi=10.1038/240091a0 |pmid= |accessdate=2013-07-07 }}</ref> "It is shown that starting with the alignment of Venus with Jupiter at perihelion position, these two planets will perfectly align at Jupiter's perihelion after every 23.7 years".<ref name=Verma>{{ cite book |author=S.D. Verma |title=Influence of Planetary Motion and Radial Alignment of Planets on Sun, In: ''Space Dynamics and Celestial Mechanics'' |publisher=Springer Netherlands |location= |year=1986 |editor=K. B. Bhatnagar |volume=127 |issue= |pages=143-54 |url=http://link.springer.com/chapter/10.1007/978-94-009-4732-0_13 |arxiv= |bibcode= |doi=10.1007/978-94-009-4732-0_13 |pmid= |isbn=978-94-010-8603-5 |accessdate=2013-07-07 }}</ref> "The tidal forces hypothesis for solar cycles has been proposed by Wood (1972) and others. Table 2 below shows the relative tidal forces of the planets on the sun. Jupiter, Venus, Earth and Mercury are called the "tidal planets" because they are the most significant. According to Wood, the especially good alignments of J-V-E with the sun which occur about every 11 years are the cause of the sunspot cycle. He has shown that the sunspot cycle is synchronous with the alignments, and J. Schove's data for 1500 year of sunspot maxima supports the 11.07 year J-V-E period average."<ref name=Tomes/> "Both the 11.86 year Jupiter tropical period (time between perihelion's or closest approaches to the sun and the 9.93 year J-S alignment periods are found in sunspot spectral analysis. Unfortunately direct calculations of the tidal forces of all planets does not support the occurrence of the dominant 11.07 year cycle. Instead, the 11.86 year period of Jupiter's perihelion dominates the results. This has caused problems for several researchers in this field."<ref name=Tomes>{{ cite journal |author=Ray Tomes |title=Towards a Unified Theory of Cycles |publisher=Cycles Research Institute |location= |month=February |year=1990 |editor= |volume= |issue= |pages=21 |url=http://cyclesresearchinstitute.org/cycles-general/tomes_unified_cycles.pdf |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2013-07-07 }}</ref> "[B]y assuming a harmonic variation having a period of 11.13 years ... the phases of such a variation [in polar diameter minus equatorial diameter of the Sun] coincide to within one-fifth of a year with the phases of the sun-spot fluctuations; that, at times corresponding to minimum of sun-spottedness, the polar diameter is relatively larger; that, at times of maximum sun-spottedness, the equatorial diameter is relatively larger. The amplitude of the variation is extremely small, but its reality would seem to be established. [This] at least renders the existence of such periodic fluctuations in the shape of the sun more probable than their non-existence."<ref name=Poor>{{ cite journal |author=Charles Lane Poor |title=An investigation of the figure of the Sun and of possible variations in its size and shape [Reprint of: Annals N.Y. Acad Sci., Vol XVIII, pp.385 - 424] |journal=Contributions from the Rutherford Observatory of Columbia University New York |month=August |year=1908 |volume=26 |issue=08 |pages=385-424 |url= |arxiv= |bibcode=1908CoRut..26..385P |doi= |pmid= |accessdate=2013-05-16 }}</ref> "Solar oblateness, the difference between the equatorial and polar diameters, reflects certain fundamental properties of the Sun. ... the oblateness reflects properties of the Sun's interior, ... [There is] a time varying, excess equatorial brightness [producing] a difference between the equatorial and polar limb darkening functions ... at times when the excess brightness is reduced, the intrinsic visual oblateness can be obtained from the observations without detailed knowledge of the excess brightness. A period of reduced excess brightness occurred in 1973 September."<ref name=Hill>{{ cite journal |author=H. A. Hill |author2=R. T. Stebbins |title=The intrinsic visual oblateness of the sun |journal=The Astrophysical Journal |month=September 1, |year=1975 |volume=200 |issue=09 |pages=471-5 |url= |arxiv= |bibcode=1975ApJ...200..471H |doi=10.1086/153813 |pmid= |accessdate=2013-05-16 }}</ref> The period of reduced excess equatorial brightness occurred between solar cycle maximum around 1970 and minimum around 1975. Considering excess equatorial brightness and seeking to perform measurements at opportunities of reduced excess equatorial brightness has the effect of reducing solar oblateness from some 86.6 ± 6.6 milli-arcsec to 18.4 ± 12.5 milli-arcsec.<ref name=Hill/> The Babcock Model describes a mechanism which can explain magnetic and sunspot patterns observed on the Sun: # The start of the 22-year cycle begins with a well-established dipole field component aligned along the solar rotational axis. The field lines tend to be held by the highly conductive solar plasma of the solar surface. # The solar surface plasma rotation rate is different at different latitudes, and the rotation rate is 20 percent faster at the equator than at the poles (one rotation every 27 days). Consequently, the magnetic field lines are wrapped by 20 percent every 27 days. # After many rotations, the field lines become highly twisted and bundled, increasing their intensity, and the resulting buoyancy lifts the bundle to the solar surface, forming a bipolar field that appears as two spots, being kinks in the field lines. # The sunspots result from the strong local magnetic fields in the solar surface that exclude the light-emitting solar plasma and appear as darkened spots on the solar surface. # The leading spot of the bipolar field has the same polarity as the solar hemisphere, and the trailing spot is of opposite polarity. The leading spot of the bipolar field tends to migrate towards the equator, while the trailing spot of opposite polarity migrates towards the solar pole of the respective hemisphere with a resultant reduction of the solar dipole moment. This process of sunspot formation and migration continues until the solar dipole field reverses (after about 11 years). # The solar dipole field, through similar processes, reverses again at the end of the 22-year cycle. # The magnetic field of the spot at the equator sometimes weakens, allowing an influx of [[Coronal cloud|coronal plasma]] that increases the internal pressure and forms a magnetic bubble which may burst and produce an ejection of coronal mass, leaving a coronal hole with open field lines. Such a coronal mass ejections are a source of the high-speed solar wind. # The fluctuations in the bundled fields convert magnetic field energy into plasma heating, producing emission of electromagnetic radiation as intense ultraviolet (UV) and X-rays. {{clear}} ==Stellar winds== [[Image:SpaceEnvironmentOverview From 19830101.jpg|thumb|right|200px|This image shows an overview of the space weather conditions over several solar cycles including the relationship between sunspot numbers and cosmic rays. Credit: [[commons:User:Daniel Wilkinson|Daniel Wilkinson]].]] "The '''solar wind''' is a stream of [[w:charged particle|charged particle]]s ejected from the [[w:stellar atmosphere|upper atmosphere]] of the [[Sun (star)|Sun]]. It mostly consists of electrons and protons with energies usually between 1.5 and 10 [[w:electronvolt|keV]]. Δ''T''_''A'' may have values from "7-19 min for a small sample of well-connected ... cosmic-ray flares."<ref name="Cliver"/> The transit time anomaly may be explained by a rise time associated with the ground-level events (GLEs). "The average GLE rise time ... for well-connected ... events ... defined to be the time from event onset to maximum as measured by the neutron monitor station showing the largest increase and whose asymptotic cone of acceptance ... includes the nominal direction of the Archimedean spiral path, is 21.3 min."<ref name="Cliver"/> The solar wind originates through the polar coronal holes. "The solar wind is a plasma, composed primarily of electrons and lone protons, and the variations in the index of refraction are caused by variations in the density of the plasma.<ref>Jokipii (1973), pp. 11–12.</ref> Different indices of refraction result in phase changes between waves traveling through different locations, which results in interference. As the waves interfere, both the frequency of the wave and its angular size are broadened, and the intensity varies.<ref>Alurkar (1997), p. 11.</ref>"<ref name=McBride>{{ cite web |author=[[w:User:James McBride|James McBride]] |title=Interplanetary scintillation |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=October 1, 2013 |url=https://en.wikipedia.org/wiki/Interplanetary_scintillation |accessdate=2014-01-23 }}</ref> ==Van Allen radiation belts== The '''Van Allen radiation belt''' is split into two distinct belts, with energetic electrons forming the outer belt and a combination of protons and electrons forming the inner belts. In addition, the radiation belts contain lesser amounts of other nuclei, such as [[w:alpha particle|alpha particle]]s. The trapped particle population of the outer belt is varied, containing electrons and various ions. Most of the ions are in the form of energetic protons, but a certain percentage are [[w:alpha particles|alpha particles]] and O⁺ oxygen ions, similar to those in the [[w:ionosphere|ionosphere]] but much more energetic. While protons form one radiation belt, trapped electrons present two distinct structures, the inner and outer belt. The inner electron Van Allen Belt extends typically from an altitude of 1.2 to 3 Earth radii (L values of 1 to 3).<ref name=Ganushkina>{{ cite journal | author=Ganushkina N.Y. |author2=I. Dandouras |author3=Y. Y. Shprits |author4=J. Cao | title=Locations of boundaries of outer and inner radiation belts as observed by Cluster and Double Star | journal=Journal of Geophysical Research | volume=116 |issue=A09234 |doi=10.1029/2010JA016376 | year=2011 | pages=1–18 |url=http://onlinelibrary.wiley.com/doi/10.1029/2010JA016376/abstract }}</ref> In certain cases when solar activity is stronger or in geographical areas such as the [[w:South Atlantic Anomaly|South Atlantic Anomaly]] (SAA), the inner boundary may go down to roughly 200 kilometers<ref>{{ cite book |title=ECSS Space engineering |date=15 November 2008 |url=https://www.scribd.com/document/122967505/ECSS-space-engineering }}</ref> above the Earth's surface. The inner belt contains high concentrations of electrons in the range of hundreds of keV and energetic protons with energies exceeding 100 MeV, trapped by the strong (relative to the outer belts) magnetic fields in the region.<ref name=Gusev>{{ cite journal | author=Gusev A.A. |author2=G.I. Pugacheva |author3=U.B. Jayanthi |author4=N. Schuch | title=Modeling of Low-altitude Quasi-trapped Proton Fluxes at the Equatorial Inner Magnetosphere | journal=Brazilian Journal of Physics | vol. 33 | no. 4 | year=2003 | pages=775–781 |url=http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-97332003000400029 }}</ref> It is believed that proton energies exceeding 50 MeV in the lower belts at lower altitudes are the result of the [[w:beta decay|beta decay]] of [[w:neutrons|neutrons]] created by cosmic ray collisions with nuclei of the upper atmosphere. The source of lower energy protons is believed to be proton diffusion due to changes in the magnetic field during geomagnetic storms.<ref name=Tascione>{{ cite book | first=Thomas F. | last=Tascione | title=Introduction to the Space Environment, 2nd. Ed. | publisher=Kreiger Publishing CO.| location=Malabar, Florida USA | year=1994 |url=http://astrobooks.com/introductiontothespaceenvironmentsecondeditionsoftbackthomasftascione-1994.aspx | isbn=0-89464-044-5}}</ref> Due to the slight offset of the belts from Earth's geometric center, the inner Van Allen belt makes its closest approach to the surface at the South Atlantic Anomaly.<ref name="Goddard">NASA Goddard Spaceflight Center, |url=http://image.gsfc.nasa.gov/poetry/tour/AAvan.html |title=The Van Allen Belts] (Accessed May 25, 2011)</ref><ref name=Underwood>{{ cite journal | author=Underwood, C. |author2=Brock, D. |author3=Williams, P. |author4=Kim, S. |author5=Dilão, R. |author6=Ribeiro Santos, P. |author7=Brito, M. |author8=Dyer, C. |author9=Sims, A. | title=Radiation Environment Measurements with the Cosmic Ray Experiments On-Board the KITSAT-1 and PoSAT-1 Micro-Satellites | journal=IEEE Transactions on Nuclear Sciences | volume=41 | year=1994 | pages=2353–2360 |url=http://ieeexplore.ieee.org/document/340587/ }}</ref> The proton belts contain [[w:protons|protons]] with kinetic energies ranging from about 100 keV (which can penetrate 0.6&nbsp;microns of lead) to over 400 MeV (which can penetrate 143&nbsp;mm of lead).<ref name=Hess>{{cite book |author=Wilmot N. Hess |title=The Radiation Belt and Magnetosphere |publisher=Blaisdell Pub. Co. |date=1968 |url=http://adsabs.harvard.edu/abs/1968rbm..book.....H }}</ref> The [[w:Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics|PAMELA]] experiment detected orders of magnitude higher levels of [[w:antiproton|antiproton]]s than are expected from normal [[w:particle decay|particle decay]]s while passing through the SAA. This suggests the van Allen belts confine a significant flux of antiprotons produced by the interaction of the Earth's upper atmosphere with [[w:cosmic rays|cosmic rays]].<ref name=Adriani>{{ cite journal | doi = 10.1088/2041-8205/737/2/L29 | title = The Discovery of Geomagnetically Trapped Cosmic-Ray Antiprotons | year = 2011 | last1 = Adriani | first1 = O. | last2 = Barbarino | first2 = G. C. | last3 = Bazilevskaya | first3 = G. A. | last4 = Bellotti | first4 = R. | last5 = Boezio | first5 = M. | last6 = Bogomolov | first6 = E. A. | last7 = Bongi | first7 = M. | last8 = Bonvicini | first8 = V. | last9 = Borisov | first9 = S. | journal = The Astrophysical Journal Letters | volume = 737 | issue = 2 | pages = L29 | bibcode = 2011ApJ...737L..29A | arxiv=1107.4882v1 }}</ref> The energy of the antiprotons has been measured in the range from 60 - 750 [[w:Electron volt|MeV]]. When cosmic-ray protons enter the Earth’s atmosphere they collide with molecules, mainly oxygen and nitrogen, to produce a cascade of billions of lighter particles, a so-called air shower. An air shower is an extensive (many kilometres wide) cascade of ionized particles and electromagnetic radiation produced in the atmosphere when a primary cosmic-ray proton (i.e. one of extraterrestrial origin) enters the atmosphere. During [[w:solar proton event|solar proton event]]s, ionization can reach unusually high levels in the D-region over high and polar latitudes. Such very rare events are known as Polar Cap Absorption (or PCA) events, because the increased ionization significantly enhances the absorption of radio signals passing through the region. In fact, absorption levels can increase by many tens of dB during intense events, which is enough to absorb most (if not all) transpolar HF radio signal transmissions. Such events typically last less than 24 to 48 hours. Associated with solar flares is a release of high-energy protons. These particles can hit the Earth within 15 minutes to 2 hours of the solar flare. The protons spiral around and down the magnetic field lines of the Earth and penetrate into the atmosphere near the magnetic poles increasing the ionization of the D and E layers. PCA's typically last anywhere from about an hour to several days, with an average of around 24 to 36 hours. ==Cosmic rays== {{main|Radiation/Cosmic rays}} "A persistent problem of solar cosmic-ray research has been the lack of observations bearing on the timing and conditions in which protons that escape to the interplanetary medium are first accelerated in the corona."<ref name="Cliver">{{cite journal |author=E. W. Cliver |author2=S. W. Kahler |author3=M. A. Shea |author4=D. F. Smart |title=Injection onsets of ~2 GeV protons, ~1 MeV electrons, and ~100 keV electrons in solar cosmic ray flares |journal=The Astrophysical Journal |month=September 1 |year=1982 |volume=260 |issue=9 |pages=362-70 |url= |arxiv= |bibcode=1982ApJ...260..362C |doi= |pmid= |accessdate=2012-08-21 }}</ref> "For solar cosmic-rays, the apparent lack of proton acceleration in the corona seems justified, in contrast to the electrons, proton bremsstrahlung and gyrosynchrotron emission are negligible. This suggests a transit time anomaly, Δ''T''_''A'', defined as follows: : Δ''T''_''A'' = Δ''T''_onset - 11 min, where Δ''T''_onset is the deduced Sun-Earth transit time for the first arriving relativistic protons and 11 min is the nominal transit time for a ~2 GeV proton traversing a 1.3 AU Archimedes spiral path."<ref name="Cliver">{{cite journal |author=E. W. Cliver |author2=S. W. Kahler |author3=M. A. Shea |author4=D. F. Smart |title=Injection onsets of ~2 GeV protons, ~1 MeV electrons, and ~100 keV electrons in solar cosmic ray flares |journal=The Astrophysical Journal |month=September 1 |year=1982 |volume=260 |issue=9 |pages=362-70 |url= |arxiv= |bibcode=1982ApJ...260..362C |doi= |pmid= |accessdate=2012-08-21 }}</ref> ==Protons== {{main|Radiation astronomy/Protons|Proton astronomy}} [[Image:GOES protons.jpg|thumb|right|250px|This graph displays the flux of high energy protons measured by GOES 11 over four days from November 2, 2004, to November 4, 2003. Credit: NOAA.]] The Sun and the solar wind, at least that portion that originates through the polar coronal holes apparently from the photosphere, may be major sources of protons within the solar system. At right is a temporal distribution of solar proton flux in units of particles cm^-2 s^-1 sr^-1 as measured by GOES 11 over the four days from November 2, 2003, to November 4, 2003, in three windows of energy: ≥ 100 MeV (green), ≥ 50 MeV (blue), and ≥ 10 MeV (red). The percentage originating from the surface of the Sun either directly or through the contribution to the solar wind is not indicated. {{clear}} ==Electrons== {{main|Radiation astronomy/Electrons}} "The density of the coronal cloud deduced in this case is about 2 x 10¹¹ electrons per cubic centimeter."<ref name=Zinn1965>{{ cite book |author=H. Zinn |title=Solar Flares and Concurrent Phenomena in the Solar Atmosphere, In: ''Proceedings of the Plasma Space Science Symposium'' |publisher=Springer |location=Netherlands |year=1965 |editor=C. C. Chang |editor2=S. S. Huang |volume=3 |issue= |pages=38-51 |url=http://link.springer.com/chapter/10.1007/978-94-011-7542-5_5 |arxiv= |bibcode= |doi=10.1007/978-94-011-7542-5_5 |pmid= |isbn=978-94-011-7544-9 |accessdate=2013-07-07 }}</ref> ==Positrons== {{main|Radiation astronomy/Positrons}} [[Image:Rhessi0269 web.jpg|thumb|right|250px|RHESSI observes high-energy phenomena from a solar flare. Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio.]] The solar flare at Active Region 10039 on July 23, 2002, exhibits many exceptional high-energy phenomena including the 2.223 MeV neutron capture line and the 511 keV electron-positron (antimatter) annihilation line. In the image at right, the RHESSI low-energy channels (12-25 keV) are represented in red and appear predominantly in coronal loops. The high-energy flux appears as blue at the footpoints of the coronal loops. Violet is used to indicate the location and relative intensity of the 2.2 MeV emission. During solar flares “[s]everal radioactive nuclei that emit positrons are also produced; [which] slow down and annihilate in flight with the emission of two 511 keV photons or form positronium with the emission of either a three gamma continuum (each photon < 511 keV) or two 511 keV photons."<ref name=Share>{{ cite book |author=Gerald H. Share |author2=Ronald J. Murphy |title=Solar Gamma-Ray Line Spectroscopy – Physics of a Flaring Star, In: ''Stars as Suns: Activity, Evolution and Planets'' |publisher=Astronomical Society of the Pacific |location=San Francisco, CA |date=January 2004 |editor=Andrea K. Dupree, A. O. Benz |pages=133-44 |url=http://heseweb.nrl.navy.mil/gamma/solar/papers/share_iau_04.pdf |arxiv= |bibcode=2004IAUS..219..133S |doi= |pmid= |isbn=158381163X |accessdate=2012-03-15 }}</ref> The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) made the first high-resolution observation of the solar positron-electron annihilation line during the July 23, 2003 solar flare.<ref name=Share/> The observations are somewhat consistent with electron-positron annihilation in a quiet solar atmosphere via positronium as well as during flares.<ref name=Share/> Line-broadening is due to "the velocity of the positronium."<ref name=Share/> "The width of the annihilation line is also consistent ... with thermal broadening (Gaussian width of 8.1 ± 1.1 keV) in a plasma at 4-7 x 10⁵ K. ... The ''RHESSI'' and all but two of the ''SMM'' measurements are consistent with densities ≤ 10¹² H cm^-3 [but] <10% of the p and α interactions producing positrons occur at these low densities. ... positrons produced by ³He interactions form higher in the solar atmosphere ... all observations are consistent with densities > 10¹² H cm^-3. But such densities require formation of a substantial mass of atmosphere at transition region temperatures."<ref name=Share/> {{clear}} ==Neutrinos== {{main|Radiation astronomy/Neutrinos|Neutrino astronomy}} [[Image:Neusun1 superk1.jpg|thumb|right|250px|This "neutrino image" of the Sun is produced by using the Super-Kamiokande to detect the neutrinos from nuclear fusion coming from the Sun. Credit: R. Svoboda and K. Gordan (LSU).]] [[Image:Bahcall Figure 2.jpg|thumb|right|250px|This figure shows a detected 94 % correlation between scaled sunspot numbers and neutrino detections. Credit: John N. Bahcall.]] Neutrinos are hard to detect. The Super-Kamiokande, or "Super-K" is a large-scale experiment constructed in an unused mine in Japan to detect and study neutrinos. The image at right required 500 days worth of data to produce the "neutrino image" of the Sun. The image is centered on the Sun's calculated position. It covers a 90° x 90° octant of the sky (in right ascension and declination). The higher the brightness of the color, the larger is the neutrino flux. The surface of the Sun is not a known source of neutrinos. Those detected may be from nucleosynthesis within the coronal cloud in the near vicinity of the Sun or perhaps from nucleosynthesis occurring interior to the Sun. "[N]eutrino flux increases noted in Homestake results [coincide] with major solar flares [14]."<ref name=Dubin>{{ cite journal |author=Maurice Dubin |author2=Robert K. Soberman |title=Resolution of the Solar Neutrino Anomaly |journal=arXiv |date=April 1996 |volume= |issue= |pages=1-8 |url=http://arxiv.org/abs/astro-ph/9604074 |arxiv=astro-ph/9604074 |bibcode=1996astro.ph..4074D |doi= |pmid= |pdf=http://arxiv.org/pdf/astro-ph/9604074.pdf |accessdate=2012-11-11 }}</ref> This result together with those in the next two paragraphs establishes that neutrinos are being produced by processes above the photosphere and probably within 2-4 solar radii as most solar flares give off energy close to and into the chromosphere. "The correlation between a great solar flare and Homestake neutrino enhancement was tested in 1991. Six major flares occurred from May 25 to June 15 including the great June 4 flare associated with a coronal mass ejection and production of the strongest interplanetary shock wave ever recorded (later detected from spacecraft at 34, 35, 48, and 53 AU) [15]. It also caused the largest and most persistent (several months) signal ever detected by terrestrial cosmic ray neutron monitors in 30 years of operation [16]. The Homestake exposure (June 1–7) measured a mean ³⁷Ar production rate of 3.2 ± 1.5 atoms/day (≈19 ³⁷Ar atoms produced in 6 days) [13]; about 5 times the rate of ≈ 0.65 day ⁻¹ for the preceding and following runs, > 6 times the long term mean of ≈ 0.5 day⁻¹ and > 2 1/2 times the highest rates recorded in ∼ 25 operating years."<ref name=Dubin/> The highest flux of solar neutrinos come directly from the proton-proton interaction, and have a low energy, up to 400 keV. There are also several other significant production mechanisms, with energies up to 18 MeV.<ref name=Bellerive>A. Bellerive, [http://arxiv.org/abs/hep-ex/0312045 Review of solar neutrino experiments]. Int.J.Mod.Phys. A19 (2004) 1167-1179</ref> The parts of the Sun above the photosphere are referred to collectively as the ''solar atmosphere''.<ref name=Abhyankar1977>{{ cite journal |author=K.D. Abhyankar |title=A Survey of the Solar Atmospheric Models 1977 |journal=Bull. Astr. Soc. India |volume=5 |bibcode=1977BASI....5...40A |pages=40–44 |url=http://prints.iiap.res.in/handle/2248/510 }}</ref> "Neutrinos can be produced by energetic protons accelerated in solar magnetic fields. Such protons produce pions, and therefore muons, hence also neutrinos as a decay product, in the solar atmosphere."<ref name=Bahcall1987>{{ cite journal |author=J. N. Bahcall |author2=G. B. Field |author3=W. H. Press |title=Is solar neutrino capture rate correlated with sunspot number? |journal=The Astrophysical Journal |date=September 1, 1987 |volume=320 |issue=9 |pages=L69-73 |url=http://articles.adsabs.harvard.edu//full/1987ApJ...320L..69B/L000069.000.html |arxiv= |bibcode=1987ApJ...320L..69B |doi=10.1086/184978 |pmid= |accessdate=2013-07-07 }}</ref> "Energetic protons in the solar corona could explain Figure 2 [at right] only if (1) they tap a substantial fraction of the entire energy generated in the corona, (2) the energy generated in the corona is at least 3 times what has been deduced from the observations, (3) the vast majority of energetic protons do not escape the Sun, (4) the proton energy spectrum is unusually hard (''p''₀ = 300 MeV c^-1, and (5) the sign of the variation is opposite to what one would predict. As the likelihood of all of these conditions being fulfilled seems extremely small, we do not believe that neutrinos produced by energetic protons in the solar atmosphere contribute significantly to the neutrino capture in the ³⁷Cl experiment."<ref name=Bahcall1987/> "The total number of neutrinos of all types agrees with the number predicted by the computer model of the Sun. Electron neutrinos constitute about a third of the total number of neutrinos. [...] The missing neutrinos were actually present, but in the form of the more difficult to detect muon and tau neutrinos."<ref name=Bahcall2004>{{ cite book |author=John N. Bahcall |title=Solving the Mystery of the Missing Neutrinos |publisher=Nobel Media AB |location= |date=April 28, 2004 |url=http://www.nobelprize.org/nobel_prizes/themes/physics/bahcall/ |accessdate=2014-03-08 }}</ref> The reactions that produce the higher energy neutrinos: ν_µ and ν_τ are. For antiproton-proton annihilation at rest, a meson result is, for example, :<math>p^+ + \bar{p}^- \rightarrow \pi^+ + \pi^-,</math><ref name=Klempt>{{ cite journal |author=Eberhard Klempt |author2=Chris Batty |author3=Jean-Marc Richard |title=The antinucleon-nucleon interaction at low energy: annihilation dynamics |journal=Physics Reports |date=July 2005 |volume=413 |issue=4-5 |pages=197-317 |url=http://adsabs.harvard.edu/abs/2005PhR...413..197K |arxiv=hep-ex/0501020 |bibcode=2005PhR...413..197K |doi=10.1016/j.physrep.2005.03.002 |pmid= |accessdate=2014-03-09 }}</ref> :<math>{\pi}^+ \rightarrow {\mu}^+ + {\nu}_{\mu} \rightarrow e^+ + {\nu}_e + {\bar{\nu}}_{\mu} + {\nu}_{\mu},</math><ref name=Waxman>{{ cite journal |author=Eli Waxman |author2=John Bahcall |title=High energy neutrinos from astrophysical sources: An upper bound |journal=Physical Review D |date=December 14, 1998 |volume=59 |issue=2 |pages=e023002 |url=http://prd.aps.org/abstract/PRD/v59/i2/e023002 |arxiv=hep--ph/9807282 |bibcode= |doi=10.1103/PhysRevD.59.023002 |pmid= |accessdate=2014-03-09 }}</ref> and :<math>D_S \rightarrow \tau + \bar{\nu}_{\tau} \rightarrow \nu_{\tau} + \bar{\nu}_{\tau}.</math><ref name=Kodama>{{ cite journal |author=K. Kodama |author2=N. Ushida1 |author3=C. Andreopoulos |author4=N. Saoulidou |author5=G. Tzanakos |author6=P. Yager |author7=B. Baller |author8=D. Boehnlein |author9=W. Freeman |author10=B. Lundberg |author11=J. Morfin |author12=R. Rameika |author13=J.C. Yun |author14=J.S. Song |author15=C.S. Yoon |author16=S.H.Chung |author17=P. Berghaus |author18=M. Kubanstev |author19=N.W. Reay |author20=R. Sidwell |author21=N. Stanton |author22=S. Yoshida |author23=S. Aoki |author24=T. Hara |author25=J.T. Rhee |author26=D. Ciampa |author27=C. Erickson |author28=M. Graham |author29=K. Heller |author30=R. Rusack |author31=R. Schwienhorst |author32=J. Sielaff |author33=J. Trammell |author34=J. Wilcox |author35=K. Hoshino |author36=H. Jiko |author37=M. Miyanishi |author38=M. Komatsu |author39=M. Nakamura |author40=T. Nakano |author41=K. Niwa |author42=N. Nonaka |author43=K. Okada |author44=O. Sato |author45=T. Akdogan |author46=V. Paolone |author47=C. Rosenfeld |author48=A. Kulik |author49=T. Kafka |author50=W. Oliver |author51=T. Patzak |author52=J. Schneps |title=Observation of tau neutrino interactions |journal=Physics Letters B |date=April 12, 2001 |volume=504 |issue=3 |pages=218-24 |url=http://www.sciencedirect.com/science/article/pii/S0370269301003070 |arxiv= |bibcode= |doi= |pmid= |accessdate=2014-03-10 }}</ref> "All other sources of ν_τ are estimated to have contributed an additional 15%."<ref name=Kodama/> :<math>\tau \rightarrow e + \nu_{\tau} + \nu_e,</math><ref name=Kodama/> for two neutrinos.<ref name=Kodama/> :<math>\tau \rightarrow h + \nu_{\tau} + X,</math><ref name=Kodama/> where <math>h</math> is a hadron, for two neutrinos.<ref name=Kodama/> {{clear}} ==Gamma rays== {{main|Radiation astronomy/Gamma rays|Gamma-ray astronomy}} [[Image:Gamma sun1.jpg|thumb|right|250px|The Sun is seen in gamma rays by COMPTEL during a June 15, 1991, solar flare. Credit: COMPTEL team, University of New Hampshire.]] The surface of the Sun has yet to be detected as a gamma ray source, reflector, or in fluorescence. RHESSI was the first satellite to image solar gamma rays from a solar flare.<ref>[http://adsabs.harvard.edu/abs/2003ApJ...595L..77H] First Gamma-Ray Images of a Solar Flare (Hurford et al. 2003)</ref> {{clear}} ==X-rays== {{main|Radiation astronomy/X-rays|X-ray astronomy}} [[Image:X-ray image of the Pleiades.gif|thumb|right|250px|The image shows the Pleiades in X-rays, taken by ROSAT, where the brightest optical stars are inside the green squares. Credit: [[w:User:Worldtraveller|Worldtraveller]].]] "The Pleiades star cluster is one of the jewels of the northern sky. To the unaided eye it appears as an alluring group of stars in the constellation Taurus, while telescopic views reveal cluster stars surrounded by delicate blue wisps of dust-reflected starlight. To the X-ray telescopes on board the orbiting ROSAT observatory, the cluster also presents an impressive, but slightly altered, appearance. This false color image [at right] was produced from ROSAT observations by translating different X-ray energy bands to visual colors - the lowest energies are shown in red, medium in green, and highest energies in blue. (The green boxes mark the position of the seven brightest visual stars.) The Pleiades stars seen in X-rays have extremely hot, tenuous outer atmospheres called coronas and the range of colors corresponds to different coronal temperatures."<ref name=Nemiroff1999>{{ cite book |author=Robert Nemiroff |author2=Jerry Bonnell |title=X-Ray Pleiades |publisher=NASA/GSFC |location=Greenbelt, Maryland USA |date=August 28, 1999 |url=http://apod.nasa.gov/apod/ap990828.html |accessdate=2013-07-07 }}</ref> {{clear}} ==Ultraviolets== {{main|Radiation astronomy/Ultraviolets|Ultraviolet astronomy}} [[Image:August 2010 CME SDO.jpg|thumb|right|200px|A coronal mass ejection is shown in the ultraviolet. Credit: NASA/SDO.]] [[Image:STEREO B EUVI 171.jpg|thumb|left|250px|The chromosphere of the Sun shows in ultraviolets. Credit: STEREO (NASA).]] "One of the fastest CMEs in years was captured by the STEREO COR1 telescopes on August 1, 2010. ... This CME is seen to be heading towards Earth at speeds well over 1000 kilometers per second."<ref name=Zell/> "On August 1st, almost the entire Earth-facing side of the sun erupted in a tumult of activity. There was a C3-class solar flare, a solar tsunami, multiple filaments of magnetism lifting off the stellar surface, large-scale shaking of the solar corona, radio bursts, a coronal mass ejection and more. This extreme ultraviolet snapshot [at right] from the Solar Dynamics Observatory (SDO) shows the sun's northern hemisphere in mid-eruption. Different colors in the image represent different gas temperatures ranging from ~1 to 2 million degrees K."<ref name=Zell>{{ cite book |author=Holly Zell |title=Spacecraft Observes Coronal Mass Ejection |publisher=NASA |location=Washington, DC USA |date=August 4, 2010 |url=http://www.nasa.gov/topics/solarsystem/sunearthsystem/main/News080210-cme.html |accessdate=2013-07-07 }}</ref> {{clear}} ==Non-polar solar coronal holes== [[Image:Coronalhole.jpg|right|thumb|250px|Solar Disk with Coronal Hole - May 25, 2007 - by NASA STEREO (Solar TErrestrial RElations Observatory). Credit: NASA STEREO (Solar TErrestrial RElations Observatory).{{tlx|free media}}]] [[Image:417176main SDO Guide CMR Page 26 Image 0002.jpg|right|thumb|250px|A coronal hole is shown in extreme UV light. Credit: NASA.{{tlx|free media}}]] [[Image:Cor hole May-thumb-570x570-123594.jpg|thumb|right|250px|Coronal holes are areas on the Sun's corona that are darker, lower-density, and (relatively) colder than the rest of the plasma above the surface of our nearest star. Credit: NASA.{{tlx|fairuse}}]] [[Image:Two Coronal Holes on the Sun Viewed by SDO (16658479920).jpg|right|thumb|250px|NASA’s Solar Dynamics Observatory, or SDO, captured this solar image on March 16, 2015, which clearly shows two dark patches, known as coronal holes. Credit: NASA/Goddard/SDO.{{tlx|free media}}]] [[Image:Coronal Hole Front and Center.jpg|right|thumb|300px|The high-speed solar wind originating from this coronal hole, imaged hereon Oct. 10, 2015, by NASA's Solar Dynamics Observatory, created a geomagnetic storm near Earth that resulted in several nights of auroras. Credit: NASA/SDO.{{tlx|free media}}]] [[Image:PIA22197-SunFormsQuestionMark-20171222.jpg|right|thumb|250px|NASA's Solar Dynamics Observatory observed an elongated coronal hole (the darker area near the center) seeming to shape itself into a single, recognizable question mark over the period of one day (Dec. 21-22, 2017). Credit: .{{tlx|free media}}]] "The striking absence of green emission above both polar regions at activity minimum led Waldmeier (1957) to use the German term 'Koronalöcher', ie, coronal holes."<ref name=Schwenn>{{ cite journal |author=R. Schwenn |author2=B. Inhester |author3=S. P. Plunkett |author4=A. Epple |author5=B. Podlipnik |author6=D. K. Bedford |author7=C. J. Eyles |author8=G. M. Simnett |author9=S. J. Tappin |author10=M. V. Bout |author11=et al. |title=First View of the Extended Green-Line Emission Corona At Solar Activity Minimum Using the Lasco-C1 Coronagraph on Soho |journal=Solar Physics |month=October |year=1997 |volume=175 |issue=2 |pages=667-84 |url=http://www.springerlink.com/index/R10HN0R60R081237.pdf |arxiv= |bibcode= |doi=10.1023/A:1004948913883 |pmid= |accessdate=2012-02-17 }}</ref> "Here we restrict ourselves to a qualitative study of large scale structures of the green emission line corona."<ref name=Schwenn/> The image descriptions that follow emphasize various non-polar holes. For the coronal hole from 25 May 2007: the image of the solar coronal cloud at top right shows both of the polar coronal holes and one apparently isolated, non-polar coronal hole. Third image down on the right: "Coronal holes are areas on the sun's corona that are darker, lower-density, and (relatively) colder than the rest of the plasma on the surface of our nearest star. They're the source of the kind of solar wind gusts that carry solar particles out to our magnetosphere and beyond, causing auroras (and, less awesomely, geomagnetic storms) here on Earth."<ref name=Garber>{{ cite book |author=Megan Garber |title=No Big Deal, Just a Giant Hole in the Sun |publisher=The Atlantic |location= |date=5 June 2013 |url=http://www.theatlantic.com/technology/archive/2013/06/no-big-deal-just-a-giant-hole-in-the-sun/276564/ |accessdate=2015-05-18 }}</ref> "When coronal holes are captured in extreme ultraviolet light images, they reveal themselves as dark spots that appear, to human eyes, to be plasma voids."<ref name=Garber/> "Well, last week -- between May 28 and 31 -- one of those coronal holes rotated toward Earth. It was a big one: "one of the largest," NASA says, "we have seen in a year or more." And the Solar Dynamics Observatory's Atmospheric Imaging Assembly, fortunately, got a shot of the thing. Above, via a combination of three wavelengths of UV light, is an image of the hole. It's pretty gorgeous, as holes go."<ref name=Garber/> "And while coronal holes are more likely to affect Earth after they've rotated more than halfway around the visible hemisphere of the sun -- which was the case with this guy -- the most this one would have done, astronomers say, was to generate some aurora."<ref name=Garber/> The image third down on the right shows one of the largest non-polar coronal holes ever observed in May, apparently in 2013. For the fourth image down on the right: "NASA’s Solar Dynamics Observatory, or SDO, captured this solar image on March 16, 2015, which clearly shows two dark patches, known as coronal holes. The larger coronal hole of the two, near the southern pole, covers an estimated 6- to 8-percent of the total solar surface. While that may not sound significant, it is one of the largest polar holes scientists have observed in decades. The smaller coronal hole, towards the opposite pole, is long and narrow. It covers about 3.8 billion square miles on the sun - only about 0.16-percent of the solar surface."<ref name=Goddard2015>{{ cite book |author=NASA/Goddard/SDO |title=Two Coronal Holes on the Sun Viewed by SDO |publisher=Goddard Space Flight Center |location=Greenbelt, Maryland USA |date=17 March 2015 |editor= |pages=1 |url=https://www.flickr.com/people/24662369@N07 |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2018-02-07 }}</ref> Per the fifth image down on the right: "The dark area across the top of the sun in this image is a coronal hole, a region on the sun where the magnetic field is open to inter planetary space, sending coronal material speeding out in what is called a high-speed solar wind stream. The high-speed solar wind originating from this coronal hole, imaged hereon Oct. 10, 2015, by NASA's Solar Dynamics Observatory, created a geomagnetic storm near Earth that resulted in several nights of auroras. This image was taken in wavelengths of 193 Angstroms, which is invisible to our eyes and is typically colorized in bronze."<ref name=NASA>{{ cite book |author=NASA/SDO |title=Coronal Hole Front and Center |publisher=GSFC |location=Greenbelt, Maryland USA |date=15 October 2015 |editor= |pages=1 |url=https://www.nasa.gov/image-feature/goddard/coronal-hole-front-and-center |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2018-02-07 }}</ref> Relative to the sixth image down on the right: "Oddly enough, an elongated coronal hole (the darker area near the center) seems to shape itself into a single, recognizable question mark over the period of one day (Dec. 21-22, 2017). Coronal holes are areas of open magnetic field that appear darker in extreme ultraviolet light, as is seen here. These holes are the source of streaming plasma that we call solar wind."<ref name=Dynamics>{{ cite web |author=NASA/GSFC/Solar Dynamics Observatory |title=PIA22197: The Sun Forms a Question |publisher=GSFC |location=Greenbelt, Maryland USA |date=29 December 2017 |editor= |pages=1 |url=https://photojournal.jpl.nasa.gov/jpeg/PIA22197.jpg |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2018-02-07 }}</ref> While the hole is connected to the polar coronal hole it does extend to mid-latitudes. {{clear}} ==Saturn== "Saturn's corona plays a major role in supplying hydrogen to the circumplanetary volume."<ref name=Smyth>{{ cite web |author=W.H. Smyth, M.R. Combi |title=Extended atmospheres of outer planet satellites and comets. Interim report, 15 June-14 September 1987 |publisher= |location= |date=November 1, 1987 |pages=122 |url=http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=5275119 |accessdate=2013-07-10 }}</ref> "This cloud probably connects to the extended hydrogen corona of Saturn (Broadfoot et al., 1981; Shemansky and Hall, 1992) and to hydrogen-rich icy surfaces in the inner magnetosphere."<ref name=Young>{{ cite journal |author=D. T. Young |author2=J. J. Berthelier |author3=M. Blanc |author4=J. L. Burch |author5=A. J. Coates |author6=R. Goldstein |author7=M. Grande |author8=T. W. Hill |author9=R. E. Johnson |author10=V. Kelha |author11=D. J. Mccomas |author12=E. C. Sittler |author13=K. R. Svenes |author14=K. Szegö |author15=P. Tanskanen |author16=K. Ahola |author17=D. Anderson |author18=S. Bakshi |author19=R. A. Baragiola |author20=B. L. Barraclough |author21=R. K. Black |author22=S. Bolton |author23=T. Booker |author24=R. Bowman |author25=P. Casey |author26=F. J. Crary |author27=D. Delapp |author28=G. Dirks |author29=N. Eaker |author30=H. Funsten |author31=J. D. Furman |author32=J. T. Gosling |author33=H. Hannula |author34=C. Holmlund |author35=H. Huomo |author36=J. M. Illiano |author37=P. Jensen |author38=M. A. Johnson |author39=D. R. Linder |author40=T. Luntama |author41=S. Maurice |author42=K. P. Mccabe |author43=K. Mursula |author44=B. T. Narheim |author45=J. E. Nordholt |author46=A. Preece |author47=J. Rudzki |author48=A. Ruitberg |author49=K. Smith |author50=S. Szalai |author51=M. F. Thomsen |author52=K. Viherkanto |author53=J. Vilppola |author54=T. Vollmer |author55=T. E. Wahl |author56=M. Wüest |author57=T. Ylikorpi |author58=C. Zinsmeyer |title=Cassini plasma spectrometer investigation |journal=Space Science Reviews |month=September |year=2004 |volume=114 |issue=1-4 |pages=1-112 |url=http://link.springer.com/article/10.1007/s11214-004-1406-4 |arxiv= |bibcode= |doi=10.1007/s11214-004-1406-4 |pmid= |accessdate=2013-07-10 }}</ref> ==Brown dwarfs== [[Image:Lp94420 duo m.jpg|thumb|250px|[[w:Chandra X-ray Observatory|Chandra]] image of LP 944-20 before flare and during flare. Credit: .]] Some brown dwarfs emit X-rays. Here are some X-ray milestones from the same article: * 1998: First X-ray-emitting brown dwarf found. Cha Halpha 1, an M8 object in the [[w:Chamaeleon I|Chamaeleon I]] dark cloud, is determined to be an X-ray source, similar to convective late-type stars. * December 15, 1999: First X-ray flare detected from a brown dwarf. A team at the University of California monitoring LP 944-20 (60 Jupiter masses, 16 ly away) via the [[w:Chandra X-ray Observatory|Chandra X-ray Observatory]], catches a 2-hour flare. X-ray flares detected from brown dwarfs since late 1999 suggest changing [[w:magnetic field of celestial bodies|magnetic fields]] similar to those in very low-mass stars. When combined with the rapid rotation that most brown dwarfs exhibit, conditions [may exist] for the development of a strong, tangled [[w:magnetic field|magnetic field]] near the surface. The flare observed by [[w:Chandra X-ray Observatory|Chandra]] from LP 944-20 could have its origin in the turbulent magnetized hot material that may conduct heat to the atmosphere, allowing electric currents to flow and produce an X-ray flare, like a stroke of [[w:lightning|lightning]]. The absence of X-rays from LP 944-20 during the non flaring period is also a significant result. It sets the lowest observational limit on steady X-ray power produced by a brown dwarf star, and shows that coronas cease to exist as the surface temperature of a brown dwarf cools below about 2500°C and becomes electrically neutral. Using NASA's [[w:Chandra X-ray Observatory|Chandra X-ray Observatory]], scientists have detected X-rays from a low-mass brown dwarf in a multiple star system.<ref name=Williams2003>{{ cite book |date=14 April 2003 |title=X-rays from a Brown Dwarf's Corona |url=http://www.williams.edu/Astronomy/jay/chapter18_etu6.html }}</ref> This is the first time that a brown dwarf this close to its parent star(s) (Sun-like stars TWA 5A) has been resolved in X-rays.<ref name=Williams2003/> "Our Chandra data show that the X-rays originate from the brown dwarf's coronal plasma which is some 3 million degrees Celsius", said Yohko Tsuboi of [[w:Chuo University|Chuo University]] in Tokyo.<ref name=Williams2003/> "This brown dwarf is as bright as the Sun today in X-ray light, while it is fifty times less massive than the Sun", said Tsuboi.<ref name=Williams2003/> "This observation, thus, raises the possibility that even massive planets might emit X-rays by themselves during their youth!"<ref name=Williams2003/> {{clear}} ==Heliophysics== {{main|Stars/Sun/Heliophysics|Heliophysics}} "Heliophysics is concerned with laws that give rise to structures and processes that occur in magnetized plasmas and in neutral environments in the local cosmos, both temporal (weather-like) and persistent (climate-like). These laws systematize the results of half a century of exploring space that followed centuries of ground-based observations. During this time spacecraft have imaged the Sun over many wavelengths and resolutions. They have visited every planet, all major satellites and many minor ones, and a selection of comets and asteroids. Beyond this they have traversed the expanse of the [[heliosphere]] itself. Out of the vast store of data so accumulated, the laws and principles of heliophysics are emerging to describe structures that are natural to magnetized plasmas and neutrals in cosmic settings and to specify principles that make the heliosphere a realm of numerous, original dynamical modes."<ref name=Siscoe>{{ cite book |author=George L. Siscoe |author2=Carolus J. Schrijver |title=Perspective on heliophysics, In: ''Heliophysics: Space Storms and Radiation: Causes and Effects'' |publisher=Cambridge University Press |location=Cambridge, UK |date=May 2010 |editor=Carolus J. Schrijver |editor2=George L. Siscoe |pages=1-10 |url=http://www.langtoninfo.com/web_content/9780521760515_excerpt.pdf |arxiv= |bibcode= |doi= |pmid= |isbn=978-0-521-76051-5 |accessdate=2014-08-02 }}</ref> "In the case of heliophysics, probably most of its laws have yet to be discovered, since the project of finding them is young. Moreover, heliophysics is a unique hybrid between meteorology and astrophysics with substantial components of physics and chemistry. Thus, many of the laws of heliophysics that we can list at this time might be subjects for research in meteorology (e.g. the field of aeronomy), astrophysics (e.g. shock waves and cosmic rays), physics (e.g. magnetic reconnection and particle energization), or chemistry (e.g. reaction rates in planetary ionospheres and thermospheres)."<ref name=Siscoe/> ==Magnetohydrodynamics== "When magnetic fields "reconnect" in a turbulent magnetohydrodynamic (MHD) plasma, electric fields are generated in which particles can be accelerated (Matthaeus ''et al.'', 1984; Sorrell, 1984)."<ref name="Gaisser">{{cite book |author=Thomas K. Gaisser |title=Cosmic Rays and Particle Physics |publisher=Cambridge University Press |location= |year=1990 |editor= |pages=279 |url=http://books.google.com/books?hl=en&lr=&id=qJ7Z6oIMqeUC&oi=fnd&pg=PR15&ots=IxjwLxBwXu&sig=voHKIYstBlBYla4jcbur_b-Zwxs |arxiv= |bibcode= |doi= |pmid= |isbn=0521339316 |accessdate=2014-01-11 }}</ref> ==Stellar sciences== {{main|Stars/Sciences}} [[Image:November 3 2009 GOES14 Image.png|thumb|right|250px|The GOES 14 spacecraft took this image of the '''Sun'''. Credit: NOAA/Space Weather Prediction Center and the NWS Internet Services Team.]] The GOES 14 spacecraft carries a Solar X-ray Imager that took this image [at right] of the '''Sun''' during the most recent quiet period. The Sun appears dark because of the wavelength band of observation and the lack of X-rays. Except for X-ray emission that suggests a circular disc with some isolated X-ray sources at specific locations, the Sun is almost invisible. X-rays are primarily emitted from plasmas near 10⁶ K. {{clear}} ==See also== {{div col|colwidth=20em}} * [[Plasmas/Plasma objects/Coronal clouds|Coronal clouds]] * [[Radiation/Cosmic rays|Cosmic-ray astronomy]] * [[Radiation astronomy/Electrons|Electron astronomy]] * [[Radiation astronomy/Fieries|Fiery meteor astronomy]] * [[Stars/Flares|Flare stars]] * [[Stars/Sun/Heliophysics|Heliophysics]] * [[Radiation astronomy/Lightnings|Lightning astronomy]] * [[Radiation astronomy/Nebulas|Nebula astronomy]] * [[Stars/Nova-likes|Nova-like stars]] * [[Stars/Novas|Novas]] * [[Stars/Os|O-type stars]] * [[Radiation astronomy/Protons|Proton astronomy]] * [[Stars/Quasars|Quasars]] * [[Stars/Star fissions|Star fissions]] * [[Stars/Active regions|Stellar active regions]] * [[Stars/Surface fusion|Surface fusions]] * [[Stars/Supernovas|Supernovas]] * [[Stars/Variables|Variable stars]] * [[Stars/Wolf-Rayets|Wolf-Rayet stars]] * [[Stars/X-rays|X-ray stars]] {{Div col end}} ==References== {{reflist|2}} ==External links== * [http://www.adsabs.harvard.edu/ The SAO/NASA Astrophysics Data System] * [http://simbad.u-strasbg.fr/simbad/ SIMBAD Astronomical Database] <!-- footer templates --> {{Radiation astronomy resources}}{{Sisterlinks|Plasma radiation astronomy}} <!-- footer categories --> [[Category:Radiation astronomy/Lectures]] nba99r9g8jbezhz18gynnm2y2km6zhq 2413996 2413990 2022-08-12T18:06:40Z Marshallsumter 311529 wikitext text/x-wiki [[Image:Media 1.ogv|thumb|right|250px|On July 19, 2012, an eruption occurred on the sun that produced a moderately powerful solar flare and a dazzling magnetic display known as coronal rain. Credit: NASA Goddard Space Flight Center, Music: 'Thunderbolt' by Lars Leonhard, courtesy of artist.{{tlx|free media}}]] A [[coronal cloud]] is a cloud, or cloud-like, natural astronomical entity, composed of plasma and usually associated with a star or other astronomical object where the temperature is such that X-rays are emitted. While small coronal clouds are above the photosphere of many different visual spectral type stars, others occupy parts of the [[interstellar medium]] (ISM), extending sometimes millions of kilometers into space, or thousands of light-years, depending on the size of the associated object such as a galaxy. {{clear}} ==Auroras== {{main|Plasmas/Plasma objects/Auroras}} [[Image:Aurora Iceland 2015 Carlos Gauna 625.jpg|thumb|right|300px|This dramatic panorama shows a colourful, shimmering auroral curtain reflected in a placid Icelandic lake. Credit: Carlos Gauna. {{tlx|fairuse}}]] '''Auroras''' can be caused by electrons being absorbed into an atmosphere. The "dramatic panorama [on the right shows a colorful], shimmering auroral curtain reflected in a placid Icelandic lake. The image was taken on 18 March 2015 by Carlos Gauna, near Jökulsárlón Glacier Lagoon in southern Iceland."<ref name=ESAGauna>{{ cite book |author=European Space Agency |title=Aurora over Icelandic Lake |publisher=ESA |location= |date=9 April 2015 |url=http://sci.esa.int/cluster/55767-aurora-over-icelandic-lake/ |accessdate=2015-04-12 }}</ref> "The celestial display was generated by a coronal mass ejection, or CME, on 15 March. Sweeping across the inner Solar System at some 3 million km per hour, the eruption reached Earth, 150 million kilometres away, in only two days. The gaseous cloud collided with Earth’s magnetic field at around 04:30 GMT on 17 March."<ref name=ESAGauna/> "When the charged particles from the Sun penetrate Earth's magnetic shield, they are channelled downwards along the magnetic field lines until they strike atoms of gas high in the atmosphere. Like a giant fluorescent neon lamp, the interaction with excited oxygen atoms generates a green or, more rarely, red glow in the night sky, while excited nitrogen atoms yield blue and purple colours."<ref name=ESAGauna/> "Auroral displays are not just decorative distractions. They are most frequent when the Sun's activity nears its peak roughly every 11 years. At such times, the inflow of high-energy particles and the buffeting of Earth’s magnetic field may sometimes cause power blackouts, disruption of radio communications, damage to satellites and even threaten astronaut safety."<ref name=ESAGauna/> {{clear}} ==Coronas== [[Image:PSM V60 D316 The solar corona.png|thumb|right|250px|The solar corona is photographed between 1901-2. Credit: [http://www.archive.org/details/popularsciencemo60newy Popular Science Monthly Volume 60].{{tlx|free media}}]] [[Image:Cp19halphajune29.png|thumb|left|250px|This is a coronagraph/polarimeter image of the solar corona on June 29, 1980, in H alpha light. Credit: NASA.{{tlx|free media}}]] '''Def.''' "[t]he luminous plasma atmosphere of the Sun or other star, extending millions of kilometres into space, most easily seen during a total solar eclipse"<ref name=CoronaWikt>{{ cite web |title=corona |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=6 September 2015 |url=https://en.wiktionary.org/wiki/corona |accessdate=2015-09-10 }}</ref> is called a '''corona''', or '''stellar corona'''. "Beginning with the daguerreotype of the corona of 1851, the Reverend Lecturer had thrown on the screen pictures illustrating the form of the corona in different years. The drawings of those of 1867, 1878, and 1900 all showed long equatorial extensions with openings at the solar poles filled with beautiful rays."<ref name=Cortie>{{ cite journal |author=A. L. Cortie |title=Synopsis of Lecture on "The Solar Corona" by the Rev. A.L. Cortie to the Members of the North-Western Branch (Manchester) on 7th November 1900 |journal=Journal of the British Astronomical Association |month=December |year=1900 |volume=11 |issue=12 |pages=77-8 |url=http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1900JBAA...11...77C&link_type=ARTICLE&db_key=AST&high= |arxiv= |bibcode=1900JBAA...11...77C |doi= |pmid= |accessdate=2011-11-09 }}</ref> "The intermediate years, as, for example, 1883, 1886, and 1896 showed the four groups of synclinals which mainly constitute the corona gradually descending towards the equator of the sun, with a corresponding opening of the polar regions."<ref name=Cortie/> "Some of the theories of the solar corona were then illustrated and discussed."<ref name=Cortie/> # "The corona is not of the nature of an atmosphere round the sun, for the pressure at the sun's limb would be enormous, while the thinness of the chromospheric lines show that it is not."<ref name=Cortie/> # "comets, such as that of 1843, have approached the sun with enormous velocities within the region of the prominences without suffering disruption or retardation."<ref name=Cortie/> # "If not an atmosphere of particles of gas, still less is it an atmosphere of solid stones or meteorites."<ref name=Cortie/> # "Meteor streams do circle round the sun, but there is no reason why the positions of the orbits, or the intrinsic brightness of such streams should vary with the sun-spot period."<ref name=Cortie/> # "the appearance of the corona does not seem to be such as the projection of meteor streams upon the celestial vault would give."<ref name=Cortie/> # "Prof. Schaeberle has proposed a mechanical origin of the solar corona, due to the forces of ejection of particles from the solar limb, as evidenced by the prominences, and the force of gravity under the particular conditions of the solar rotation and the inclination of its axis to the earth's orbit."<ref name=Cortie/> # "The electrical theory of the corona does not negative the mechanical theory, but supplements it. In addition to the forces of gravity and ejection, it takes account of the repulsive force which the sun exerts on matter which has the same electrical sign as itself, and which has been ejected from it."<ref name=Cortie/> # "it would seem that the solar corona is of the nature of an electrical aurora round the sun."<ref name=Cortie/> # "the coronoidal discharges in poor vacua obtained by Prof. Pupin about an insulated metal ball are exceedingly like the rays and streamers of the solar corona."<ref name=Cortie/> The Sun's hot [[w:corona|corona]] continuously expands in space creating the [[w:solar wind|solar wind]], a stream of charged particles that extends to the [[w:heliopause|heliopause]] at roughly 100 [[w:astronomical units|astronomical units]]. The bubble in the [[interstellar medium]] formed by the solar wind, the [[w:heliosphere|heliosphere]], is the largest continuous structure in the Solar System.<ref>{{ cite web |date=22 April 2003 |title=A Star with two North Poles |url=http://science.nasa.gov/headlines/y2003/22apr_currentsheet.htm |work=Science @ NASA |publisher=NASA }}</ref><ref name=Riley>{{ cite journal |last=Riley |first=P. |last2=Linker |first2=J. A. |last3=Mikić |first3=Z. |year=2002 |title=Modeling the heliospheric current sheet: Solar cycle variations |url=http://ulysses.jpl.nasa.gov/science/monthly_highlights/2002-July-2001JA000299.pdf |journal=Journal of Geophysical Research |volume=107 |issue=A7 |pages=SSH 8–1 |bibcode=2002JGRA.107g.SSH8R |doi=10.1029/2001JA000299 |id=CiteID 1136 }}</ref> The sun's [[w:corona|corona]] is constantly being lost to space, creating what is essentially a very thin [[w:atmosphere|atmosphere]] throughout the [[Solar System]]. The movement of mass ejected from the Sun is known as the [[w:solar wind|solar wind]]. Inconsistencies in this wind and larger events on the surface of the star, such as [[w:coronal mass ejection|coronal mass ejection]]s, form a system that has features analogous to conventional weather systems (such as pressure and wind) and is generally known as [[w:space weather|space weather]]. Coronal mass ejections have been tracked as far out in the [[w:solar system|solar system]] as [[Saturn]].<ref name=Christensen>Bill Christensen. [http://www.space.com/businesstechnology/technology/technovel_shock_041105.html Shock to the (Solar) System: Coronal Mass Ejection Tracked to Saturn.] Retrieved on 28 June 2008.</ref> The activity of this system can affect planetary [[w:atmospheres|atmospheres]] and occasionally surfaces. The interaction of the [[w:solar wind|solar wind]] with the terrestrial atmosphere can produce spectacular [[w:Aurora (astronomy)|aurorae]],<ref name=AlaskaReport>AlaskaReport. [http://alaskareport.com/science10043.htm What Causes the Aurora Borealis?] Retrieved on 28 June 2008.</ref> and can play havoc with electrically sensitive systems such as [[w:Electric power transmission|electricity grids]] and radio signals. {{clear}} ==Coronal arcades== [[Image:Coronal_arcade.png|thumb|right|250px|This is a TRACE image of the coronal arcade structure in the flare on Bastille Day, 1998. Credit: NASA.{{tlx|free media}}]] '''Def.''' a close collection of loops in a cylindrical structure is called an '''arcade'''. The TRACE image at right "is from near flare maximum (11:00 UT) and has a width of 230,000 km [...] how in the world can the footpoints of the arcade have such a clearly-organized pattern whose scale greatly exceeds the known scales of the largest convective scales known in the photosphere?"<ref name=Handy>{{ cite book |author=Brian Handy, Hugh Hudson |title=Super Regions |publisher=University of Montana |location=Helena, Montana, USA |date=July 14, 2000 |url=http://solar.physics.montana.edu/nuggets/2000/000714/000714.html |accessdate=2012-11-09 }}</ref> "The most obvious coronal signatures of CMEs in the low corona are the arcades of bright loops that develop after the CME material has erupted [...] nearly all (92%) EIT post-eruptive arcades from 1997 – 2002 were associated with LASCO CMEs [...] The activity associated with halo CMEs includes the formation of dimming regions, long-lived loop arcades, flaring active regions, large-scale coronal waves and filament eruptions".<ref name=Webb>{{ cite journal |author=David F. Webb, Timothy A. Howard |title=Coronal Mass Ejections: Observations |journal=Living Reviews in Solar Physics |year=2012 |volume=9 |issue= |pages=3 |url=http://www.boulder.swri.edu/~howard/Papers/2012_lrsp.pdf |arxiv= |bibcode= |doi= |pmid= |accessdate=2012-11-11 }}</ref> {{clear}} ==Coronal clouds== [[Image:2011 03 sun030311.jpg|thumb|right|200px|This image is taken in Hα of the Sun and above showing a cloud above a sunspot. Credit: Alan Friedman.{{tlx|fairuse}}]] "Coronal clouds, type IIIg, form in space above a spot area and rain streamers upon it."<ref name=Pettit43>{{ cite journal |author=Edison Pettit |title=The Properties of Solar Prominences as Related to Type |journal=Astrophysical Journal |month=July |year=1943 |volume=98 |issue=7 |pages=6-19 |url= |bibcode=1943ApJ....98....6P |doi=10.1086/144539 |pmid= |accessdate=2011-08-01 }}</ref> "[C]oronal magnetic bottles, produced by flares, [may] serve as temporary traps for solar cosmic rays ... It is the expansion of these bottles at velocities of 300–500 km/s which allows fast azimuthal propagation of solar cosmic rays independent of energy. A coronagraph on [[w:OSO 7|Os 7]] observed a coronal cloud which was associated with bifurcation of the underlying coronal structure."<ref name="Schatten">{{cite journal |author=K. H. Schatten, D. J. Mullan |title=Fast azimuthal transport of solar cosmic rays via a coronal magnetic bottle |journal=Journal of Geophysical Research |month=December 1, |year=1977 |volume=82 |issue=35 |pages=5609-20 |url=http://www.agu.org/pubs/crossref/1977/JA082i035p05609.shtml |arxiv= |bibcode= |doi=10.1029/JA082i035p05609 |pmid= |accessdate=2013-07-07 }}</ref> In a coronal cloud are [[Magnetohydrodynamics|magnetohydrodynamic]] plasma flux tubes along magnetic field lines.<ref name=Aschwanden/> {{clear}} ==Coronal heating== "The photosphere of the Sun has an effective temperature of 5,570 K<ref name=Massey>{{ cite journal |author=Massey P |author2=Silva DR |author3=Levesque EM |author4=Plez B |author5=Olsen KAG |author6=Clayton GC |author7=Meynet G |author8=Maeder A |title=Red Supergiants in the Andromeda Galaxy (M31) |journal=The Astrophysical Journal |volume=703 |year=2009 |issue=1 |page=420 |doi=10.1088/0004-637X/703/1/420 |bibcode=2009ApJ...703..420M }}</ref> yet its corona has an average temperature of 1–2 x 10⁶ K.<ref name=Erdelyi>{{ cite journal |author=Erdèlyi R |author2=Ballai I |title=Heating of the solar and stellar coronae: a review |year=2007 |journal=Astron Nachr |volume=328 |issue=8 |page=726 |doi=10.1002/asna.200710803 |bibcode=2007AN....328..726E }}</ref> However, the hottest regions are 8–20 x 10⁶ K.<ref name=Erdelyi/> The high temperature of the corona shows that it is heated by something other than direct [[w:Heat conduction|heat conduction]] from the photosphere.<ref name=Russell2001>{{ cite book |author=Russell CT |title=Space Weather (Geophysical Monograph) |year=2001 |publisher=American Geophysical Union |chapter=Solar wind and interplanetary magnetic field: A tutorial |editor=Song, Paul |editor2=Singer, Howard J. |editor3=Siscoe, George L. |isbn=9780875909844 |pages=73–88 |url=http://www-ssc.igpp.ucla.edu/personnel/russell/papers/SolWindTutorial.pdf }}</ref> It is thought that the energy necessary to heat the corona is provided by turbulent motion in the convection zone below the photosphere, and two main mechanisms have been proposed to explain coronal heating.<ref name=Erdelyi/> The first is [[w:wave|wave]] heating, in which sound, gravitational or magnetohydrodynamic waves are produced by turbulence in the convection zone.<ref name=Erdelyi/> These waves travel upward and dissipate in the corona, depositing their energy in the ambient gas in the form of heat.<ref name=Alfven>{{ cite journal |author=Alfvén H |title=Magneto-hydrodynamic waves, and the heating of the solar corona |bibcode=1947MNRAS.107..211A |journal=Monthly Notices of the Royal Astronomical Society |volume=107 |page=211 |year=1947 }}</ref> The other is [[w:magnetic field|magnetic]] heating, in which magnetic energy is continuously built up by photospheric motion and released through [[w:magnetic reconnection|magnetic reconnection]] in the form of large [[w:solar flare|solar flare]]s and myriad similar but smaller events—[[w:nanoflares|nanoflares]].<ref name=Parker2>{{ cite journal |author=Parker EN |title=Nanoflares and the solar X-ray corona |journal=The Astrophysical Journal |volume=330 |page=474 |year=1988 |doi=10.1086/166485 |bibcode=1988ApJ...330..474P }}</ref> Currently, it is unclear whether waves are an efficient heating mechanism. All waves except [[w:Alfvén wave|Alfvén wave]]s have been found to dissipate or refract before reaching the corona.<ref name=Sturrock>{{ cite journal |author=Sturrock PA, Uchida Y |title=Coronal heating by stochastic magnetic pumping |journal=The Astrophysical Journal |volume=246 |page=331 |year=1981 |doi=10.1086/158926 |bibcode=1981ApJ...246..331S }}</ref> In addition, Alfvén waves do not easily dissipate in the corona. Current research focus has therefore shifted towards flare heating mechanisms.<ref name=Erdelyi/>"<ref name=XrayAstronomy>{{ cite web |title=X-ray astronomy, In: ''Wikipedia'' |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=June 11, 2012 |url=http://en.wikipedia.org/wiki/X-ray_astronomy |accessdate=2012-06-29 }}</ref> ==Coronal loops== [[Image:AR1520 and Shimmering Coronal Loops.ogv|thumb|250px|right|This movie shows the evolution of active region 1520, including coronal loops. Credit: NASA/Goddard Space Flight Center.{{tlx|free media}}]] [[Image:Traceimage.jpg|thumb|right|250px|This image of coronal loops observed by the Transition Region And Coronal Explorer ([[w:TRACE|TRACE]]) shows that not all rays travel in straight lines. Credit: NASA.{{tlx|free media}}]] Coronal loops have become very important when trying to understand the current ''coronal heating problem''. Coronal loops are highly radiating sources of plasma and therefore easy to observe by instruments such as ''TRACE''; they are highly observable ''laboratories'' to study phenomena such as solar oscillations, wave activity and [[w:Nanoflares|nanoflares]]. However, it remains difficult to find a solution to the coronal heating problem as these structures are being observed remotely, where many ambiguities are present (i.e. radiation contributions along the [line-of-sight propagation] LOS). ''In-situ'' measurements are required before a definitive answer can be arrived at, but due to the high plasma temperatures in the corona, in-situ measurements are impossible (at least for the time being). The next mission of the Nasa [[w:Solar Probe Plus|Solar Probe Plus]] will approach the Sun very closely allowing more direct observations. "The peak continuum intensity was always at the loop tops."<ref name=Zirin1981>{{ cite journal |author=H. Zirin |author2=U. Feldman |author3=G. A. Doschek |author4=S. Kane |title=On the relationship between soft X-rays and Hα-emitting structures during a solar flare |journal=The Astrophysical Journal |month=May 15, |year=1981 |volume=246 |issue=05 |pages=321-30 |url=http://adsabs.harvard.edu/full/1981ApJ...246..321Z |arxiv= |bibcode=1981ApJ...246..321Z |doi=10.1086/158925 |pmid= |accessdate=2013-07-10 }}</ref> The population of coronal loops can be directly linked with the [[w:solar cycle|solar cycle]]; it is for this reason coronal loops are often found with sunspots at their footpoints. Coronal loops project through the [[w:chromosphere|chromosphere]] and [[w:transition region|transition region]], extending high into the [[Coronal cloud|corona]]. Coronal loops have a wide variety of temperatures along their lengths. Loops existing at temperatures below 1&nbsp;MK are generally known as cool loops, those existing at around 1&nbsp;MK are known as warm loops, and those beyond 1&nbsp;MK are known as hot loops. Naturally, these different categories radiate at different wavelengths.<ref name=Vourlidas>{{cite journal | author = A. Vourlidas |author2=J. A. Klimchuk |author3=C. M. Korendyke |author4=T. D. Tarbell |author5=B. N. Handy | title = On the correlation between coronal and lower transition region structures at arcsecond scales | journal = The Astrophysical Journal | volume = 563 | issue = 1 | pages = 374–80 | year = 2001 | doi = 10.1086/323835 | bibcode=2001ApJ...563..374V }}</ref> Coronal loops populate both active and quiet regions of the solar surface. Active regions on the solar surface take up small areas but produce the majority of activity and 82% of the total coronal heating energy.<ref name=Aschwanden>{{ cite journal | author = M. J. Aschwanden | title = An evaluation of coronal heating models for Active Regions based on Yohkoh, SOHO, and TRACE observations | journal = The Astrophysical Journal | volume = 560 | issue = 2 | pages = 1035–44 | year = 2001 | doi = 10.1086/323064 | bibcode=2001ApJ...560.1035A }}</ref> The quiet Sun, although less active than active regions, is awash with [[w:dynamics (mechanics)|dynamic]] processes and [[w:transient astronomical event|transient]] events (bright points, nanoflares and jets).<ref name=Aschwanden04>{{ cite book | author = M. J. Aschwanden | title = Physics of the Solar Corona. An Introduction | publisher = Praxis Publishing Ltd. | date = 2004 | isbn = 3-540-22321-5 }}</ref> As a general rule, the quiet Sun exists in regions of closed magnetic structures, and active regions are highly dynamic sources of explosive events. It is important to note that observations suggest the whole corona is massively populated by open and closed magnetic fieldlines. A closed fieldline does not constitute a coronal loop; however, closed flux must be ''filled with plasma'' before it can be called a coronal loop. The image at right shows particle rays leaving the surface of the Sun (darker ends of the loops), traveling in a loop controlled by a local magnetic field similar to how particle accelerators accelerate, steer, and aim a stream of particles at a target (the much brighter regions in the chromosphere). The loops have a temperature of approximately 10⁶ K and are emitting X-rays (synchrotron and cyclotron radiation). Coronal loops form the basic structure of the lower corona andtransition region of the Sun. These highly structured and elegant loops are a direct consequence of the twisted solar magnetic flux within the solar body. The population of coronal loops can be directly linked with the solar cycle; it is for this reason coronal loops are often found with sunspots at their footpoints. The upwelling magnetic flux pushes through the photosphere, exposing the cooler plasma below. Loops of magnetic flux (closed flux tubes) well up from the solar body and fill with hot solar plasma.<ref name=Katsukawa>{{ cite journal |author=Yukio Katsukawa |author2=Saku Tsuneta |title=Magnetic Properties at Footpoints of Hot and Cool Loops |journal=The Astrophysical Journal |month=March |year=2005 |volume=621 |issue=1 |pages=498-511 |url=http://iopscience.iop.org/0004-637X/621/1/498/pdf/0004-637X_621_1_498.pdf |arxiv= |bibcode=2005ApJ...621..498K |doi=10.1086/427488 |pmid= |accessdate=2011-12-09 }}</ref> Due to the heightened magnetic activity in these coronal loop regions, coronal loops can often be the precursor to solar flares and coronal mass ejections (CMEs). {{clear}} ==Coronal mass ejections== {{main|Radiation/Meteors}} [[Image:Coronal Mass Ejection.gif|thumb|right|250px|Arcs rise above an active region on the surface of the Sun in this series of images taken by the STEREO (Behind) spacecraft. Credit: Images courtesy of the NASA STEREO Science Center.{{tlx|free media}}]] '''Def.''' a "massive burst of solar wind, other light isotope plasma, and magnetic fields rising above the solar corona or being released into space"<ref name=CoronalMassEjectionWikt>{{ cite book |title=coronal mass ejection |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=June 21, 2013 |url=http://en.wiktionary.org/wiki/coronal_mass_ejection |accessdate=2013-07-07 }}</ref> is called a '''coronal mass ejection''' (CME). An explosive limb flare occurred above 30,000 km in the corona of the [[Sun (star)|Sun]].<ref name=Zirin/> "So the aftermath of the flare explosion, usually visible in disk pictures as extensive Hα brightening, but hidden from us in this case, was seen by the ionosphere as an intense flux of ionizing radiation from the coronal cloud created by the explosion."<ref name=Zirin>{{ cite journal |author=Harold Zirin |title=The Limb Flare of November 20, 1960: a Coronal Phenomenon |journal=Astrophysical Journal |month=October |year=1964 |volume=140 |issue=10 |pages=1216-35 |url= |bibcode=1964ApJ...140.1216Z |doi=10.1086/148019 |pmid= |accessdate=2011-08-01 }}</ref> "The November 20, 1960, event is very similar to that of February 10, 1956, which was observed at Sacramento Peak. A bright ball appears above the surface, grows in size and Hα brightness, and explodes upward and outward."<ref name=Zirin/> "The great breadth and intensity of the Hα emission from the suspended ball at 2013 U.T. testify to the large amount of energy stored there, as no corresponding macroscopic motion was observed until the explosion at 2023 U.T."<ref name=Zirin/> "[T]he great energy of the preflare cloud was released into the corona by the explosion of 2023 U.T., and Hα radiation disappeared by 2035 U.T."<ref name=Zirin/> "On 16 June 1972, the [[w:Naval Research Laboratory|Naval Research Laboratory]]'s coronagraph aboard [[w:OSO-7|OSO-7]] tracked a huge coronal cloud moving outward from the [[Sun (star)|Sun]]."<ref name=Koomen>{{ cite journal |author=Martin Koomen |author2=Russell Howard |author3=Richard Hansen |author4=Shirley Hansen |title=The coronal transient of 16 June 1972 |journal=Solar Physics |month=February |year=1974 |volume=34 |issue=2 |pages=447-52 |url=http://link.springer.com/article/10.1007/BF00153680 |arxiv= |bibcode= |doi=10.1007/BF00153680 |pmid= |accessdate=2013-07-10 }}</ref> A [[w:coronal mass ejection|coronal mass ejection]] (CME) is an ejected plasma consisting primarily of electrons and [[w:proton|proton]]s (in addition to small quantities of heavier elements such as helium, oxygen, and iron), plus the entraining coronal closed magnetic field regions. Evolution of these closed magnetic structures in response to various photospheric motions over different time scales (convection, differential rotation, meridional circulation) somehow leads to the CME.<ref name=Gopalswamy>{{ cite journal |author=Gopalswamy N |author2=Mikic Z |author3=Maia D |author4=Alexander D |author5=Cremades H |author6=Kaufmann P |author7=Tripathi D |author8=Wang YM |title=The pre-CME Sun |journal=Space Sci Rev |year=2006 |volume=123 |issue=1–3 |page=303 |doi=10.1007/s11214-006-9020-2 |bibcode = 2006SSRv..123..303G }}</ref> Small-scale energetic signatures such as plasma heating (observed as compact soft X-ray brightening) may be indicative of impending CMEs. The soft X-ray sigmoid (an S-shaped intensity of soft X-rays) is an observational manifestation of the connection between coronal structure and CME production.<ref name=Gopalswamy/> "Relating the sigmoids at X-ray (and other) wavelengths to magnetic structures and current systems in the solar atmosphere is the key to understanding their relationship to CMEs."<ref name=Gopalswamy/> {{clear}} ==Coronal streamers== [[Image:Parker Solar Probe coronal stream wispr-big 1-st flyby.jpg|thumb|right|250px|This image from Parker Solar Probe's WISPR (Wide-field Imager for Solar Probe) instrument shows a coronal streamer, seen over the east limb of the Sun on Nov. 8, 2018, at 1:12 a.m. EST. Credit: NASA/NRL/Parker Solar Probe.{{tlx|free media}}]] The '''interconnections of active regions''' are arcs connecting zones of opposite magnetic field, in different active regions. Significant variations of these structures are often seen after a flare. Some other features of this kind are [[w:helmet streamer|helmet streamer]]s—large cap-like coronal structures with long pointed peaks that usually overlie sunspots and active regions. Coronal streamers are considered as sources of the slow [[w:solar wind|solar wind]].<ref name=Ofman>{{ cite journal | doi= 10.1029/2000GL000097 | last= Ofman | first= Leon | title= Source regions of the slow solar wind in coronal streamers | journal= Geophysical Research Letters | volume = 27 | issue= 18 | pages= 2885–8 |year=2000 | bibcode=2000GeoRL..27.2885O }}</ref> Coronal streamers are structures of solar material within the Sun's atmosphere, the corona, that usually overlie regions of increased solar activity. The fine structure of the streamer in the image on the right is very clear, with at least two rays visible. Parker Solar Probe was about 16.9 million miles from the Sun's surface when this image was taken. The bright object near the center of the image is Mercury, and the dark spots are a result of background correction. {{clear}} ==Dynamos== [[Image:SolarCycle25 Prediction Bhowmik Nandy 2018.jpg|thumb|right|250px|This figure is the outcome of the first ever century-scale, data driven, coupled solar surface flux transport model and solar internal dynamo model simulation which was utilized to predict the amplitude and timing of sunspot cycle 25. Credit: [[c:user:Idnan007|Idnan007]].{{tlx|free media}}]] "A plasma with local magnetohydrodynamic instabilities creates mechanical turbulence, motion, or shear (a dynamo) which in turn generates or sustains the local magnetic field."<ref name=RadiativeDynamo>{{ cite web |title=Radiative dynamo |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=June 30, 2012 |url=http://en.wikiversity.org/wiki/Radiative_dynamo |accessdate=2012-07-06 }}</ref> This prediction in the image on the right<ref name=Bhowmik>“Prediction of the strength and timing of sunspot cycle 25 reveal decadal-scale space environmental conditions”, Bhowmik, P., and Nandy, D. 2018, Nature Communications, 9, 5209 (https://www.nature.com/articles/s41467-018-07690-0)</ref> indicates that solar cycle 25 would be a weak, but not insignificant cycle. The ensemble prediction ranges from a cycle slightly weaker to slightly stronger compared to solar cycle 24. {{clear}} ==Electromagnetics== {{main|Radiation astronomy/Electromagnetics}} "The first systematic attempt to base a theory of the origin of the solar system on electromagnetic or hydromagnetic effects was made in Alfvén (1942). The reason for doing so was that a basic difficulty with the old Laplacian hypothesis: how can a central body (Sun or planet) transfer angular momentum to the secondary bodies (planets or satellites) orbiting around it? It was demonstrated that this could be done by electromagnetic effects. No other acceptable mechanism has yet been worked out. [...] the electromagnetic transfer mechanism has been confirmed by observations, as described in the monograph ''Cosmic Plasma'' (Alfvén, 1981, pp. 28, 52, 53 0."<ref name=Alfven1981>{{ cite journal |author=Hannes Alfvén |title=The Voyager 1/Saturn Encounter and the Cosmogonic Shadow Effect |journal=Astrophysics and Space Science |month=October |year=1981 |volume=79 |issue=2 |pages=491-505 |url=http://adsabs.harvard.edu/abs/1981Ap&SS..79..491A |arxiv= |bibcode=1981Ap&SS..79..491A |doi=10.1007/BF00649444 |pmid= |accessdate=2013-12-19 }}</ref> "If charged particles (electrons, ions or charged grains) move in a magnetic dipole field - strong enough to dominate their motion - under the action of gravitation and the centrifugal force, they will find an equilibrium in a circular orbit if their centrifugal force is 2/3 of the gravitational force [...] The consequence of this is that if they become neutralized, so that electromagnetic forces disappear, the centrifugal force is too small to balance the gravitation. Their circular orbit changes to an elliptical orbit with the semi-major axis ''a'' = 3/4''a''₀ and ''e'' = 1/3 (where ''a''₀ is the central distance where the neutralization takes place [...] Collisional (viscous) interaction between the condensed particles will eventually change the orbit into a new circular orbit with ''a'' = 2/3''a''₀ and ''e'' = 0."<ref name=Alfven1981/> "If [...] there is plasma in the region [collisional interaction results in] matter in the 2/3-[region]. [...] matter in the region [...] will produce a [cosmogonic] ''shadow'' in the region".<ref name=Alfven1981/> ==Electron winds== As of December 5, 2011, "Voyager 1 is about ... 18 billion kilometers ... from the [S]un [but] the direction of the magnetic field lines has not changed, indicating Voyager is still within the heliosphere ... the outward speed of the solar wind had diminished to zero in April 2010 ... inward pressure from interstellar space is compacting [the magnetic field] ... Voyager has detected a 100-fold increase in the intensity of high-energy electrons from elsewhere in the galaxy diffusing into our solar system from outside ... [while] the [solar] wind even blows back at us."<ref name=Cole>{{ cite web |author=Steve Cole |author2=Jia-Rui C. Cook |author3=Alan Buis |title=NASA's Voyager Hits New Region at Solar System Edge |publisher=NASA |location=Washington, DC |date=December 2011 |url=http://www.nasa.gov/home/hqnews/2011/dec/HQ_11-402_AGU_Voyager.html |accessdate=2012-02-09 }}</ref> ==Flares== [[Image:06 Major Solar Flare (2820012601).jpg|thumb|right|250px|The solar flare shown in this image was captured on December 13, 2006. Credit: [https://www.flickr.com/people/11304375@N07 Image Editor].{{tlx|free media}}]] "[A] medium-strength flare erupted from the sun on July 19, 2012. The blast also generated the enormous, shimmering plasma loops, which are an example of a phenomenon known as "coronal rain," agency officials said."<ref name=WallRain>{{ cite book |author=Mike Wall |title=Super-Hot Plasma 'Rain' Falls on Sun in Amazing Video |publisher=Yahoo! News |location= |date=February 21, 2013 |url=http://news.yahoo.com/super-hot-plasma-rain-falls-sun-amazing-video-190147271.html |accessdate=2013-02-23 }}</ref> "The ... solar proton flare on 20 April 1998 at W 90° and S 43° (9:38 UT) was measured by the GOES-9-satellite (Solar Geophysical Data 1998), as well as by other experiments on WIND ... and GEOTAIL. Protons were accelerated up to energies > 110 MeV and are therefore able to hit the surface of Mercury."<ref name="Kirsch">{{cite book |author=E. Kirsch |author2=U.A. Mall |author3=B. Wilken |author4=G. Gloeckler |author5=A.B. Galvin |author6=K. Cierpka |title=Detection of Pickup- and Sputter Ions by Experiment SMS on the WIND-S/C After a Mercury Conjunction, In: ''Proceedings of the 26th International Cosmic Ray Conference'' |publisher=International Union of Pure and Applied Physics (IUPAP) |location=Salt Lake City, Utah, USA |date=August 17, 1999 |editor=D. Kieda |editor2=M. Salamon |editor3=B. Dingus |pages=212-5 |url= |arxiv= |bibcode=1999ICRC....6..212K |doi= |pmid= |isbn= }}</ref> Hinode's Solar Optical Telescope (SOT) provides crystal-clear images of features on the sun's surface. This image on the right shows a whirl of a new developing sunspot colliding with an existing spot that explodes into a major solar flare. The solar flare shown was captured on December 13, 2006. The flare produced high-energy protons that reached the Earth at the time of STS-116 Space Shuttle flight. The flare is shown in 3 different wavelengths. {{clear}} ==Flare stars== [[Image:ADLeoLightCurve.png|thumb|right|250px|U, B, V and R band light curves are for a flare on AD Leonis, adapted from Hawley and Pettersen, The Astrophysical Journal, vol 378, pp 725-741, 1991. Credit: [[c:user:PopePompus|PopePompus]].{{tlx|free media}}]] "Flare stars are intrinsically faint, but have been found to distances of 1,000 [[w:light year|light year]]s from Earth.<ref name=Kulkarni>{{ cite journal |author=Kulkarni SR, Rau A |year=2006 |bibcode=2006ApJ...644L..63K |title=The Nature of the Deep Lens Survey Fast Transients |journal=The Astrophysical Journal |doi=10.1086/505423 |volume=644 |issue=1 |pages=L63 |arxiv = astro-ph/0604343 }}</ref> {{clear}} ==Galactic coronas== Although a galactic corona is usually "filled with high-temperature plasma at temperatures of T ≈ 1–2 (MK), ... [h]ot active regions and postflare loops have plasma temperatures of T ≈ 2–40 MK."<ref name=Aschwanden2007>{{ cite journal |author=Markus J. Aschwanden |title=Fundamental Physical Processes in Coronae: Waves, Turbulence, Reconnection, and Particle Acceleration In: ''Waves & Oscillations in the Solar Atmosphere: Heating and Magneto-Seismology'' |journal=Proceedings IAU Symposium |year=2007 |editor=Erdelyi R |volume=3 |issue= S247 |pages=257–68 |arxiv=0711.0007 |url=http://journals.cambridge.org/download.php?file=%2FIAU%2FIAU3_S247%2FS1743921308014956a.pdf&code=7c95b408db74ccbe9f1f376d4cb1ef35 |doi=10.1017/S1743921308014956 }}</ref> "Discussion of the alternative hypothesis of cloud ejection from the equatorial layer of the Galaxy leads to the conclusion that the gaseous halo must be highly turbulent and that the coronal clouds are probably [[w:H I region|H I region]]s".<ref name=Grzedzielski>{{ cite journal |author=Grzędzielski, S. |author2=Stępień, K. |title=On the Cloudy Structure of the Galactic Gaseous Corona |journal=Acta Astronomica |year=1963 |volume=13 |issue= |pages=143-56 |url= |bibcode=1963AcA....13..143G |doi= |pmid= |accessdate=2011-08-01 }}</ref> "One question posed by these previous observations is where the absorption originates. If a coronal cloud, the cloud is more than 15 kpc from the plane of NGC 3067. This distance is greater than the optical radius of the galaxy, 9.6 kpc (''H'' = 50 km s^-1 Mpc^-1. Furthermore, the narrow line requires that the cloud be cool, in contrast to the wide range of ionization stages detected for the corona of our Galaxy (Savage and deBoer 1981)."<ref name=Rubin>{{ cite journal |author=Rubin V. C. |author2=Thonnard N. T. |author3=Ford W. K. Jr. |title=NGC 3067 - Additional evidence for nonluminous matter |journal=Astronomical Journal |month=March |year=1982 |volume=87 |issue=3 |pages=477-85 |url= |bibcode=1982AJ.....87..477R |doi=10.1086/113120 |pmid= |accessdate=2011-08-01 }}</ref> "But if the cloud originates instead in the disk, and is moving in a circular orbit viewed at an inclination of 68 deg (the inclination of the optical galaxy), then some gas extends at least to 40 kpc, which is over four times the optical radius."<ref name=Rubin/> ==Helmet streamers== [[Image:Helmet streamers at max.gif|thumb|right|250px|An abundance of helmet streamers is shown at solar maximum. Credit: NASA.]] [[Image:Helmet streamers at min.jpg|thumb|left|250px|Helmet streamers are shown at solar minimum restricted to mid latitudes. Credit: NASA.]] '''Helmet streamers''' are bright loop-like structures which develop over active regions on the [[Stars/Sun|sun]]. They are closed magnetic loops which connect regions of opposite magnetic polarity. Electrons are captured in these loops, and cause them to glow very brightly. The solar wind elongates these loops to pointy tips. They far extend above most prominences into the [[Coronal cloud|corona]], and can be readily observed during a solar eclipse. Helmet streamers are usually confined to the "streamer belt" in the mid latitudes, and their distribution follows the movement of active regions during the [[w:solar cycle|solar cycle]]. Small blobs of plasma, or "plasmoids" are sometimes released from the tips of helmet streamers, and this is one source of the slow component of the [[w:solar wind|solar wind]]. In contrast, formations with open magnetic field lines are called [[w:coronal holes|coronal holes]], and these are darker and are a source of the fast solar wind. Helmet streamers can also create coronal mass ejections if a large volume of plasma becomes disconnected near the tip of the streamer. {{clear}} ==Ionospheres== [[Image:Ionosphere-Thermosphere Processes.jpg|thumb|right|250px|In this diagram, the prominent features in the ionosphere-thermosphere system and their coupling to the different energy inputs show the complex temporal and spatial phenomena that are generated. Credit: NASA.]] Upon reaching the top of the [[w:Mesosphere|mesosphere]], the temperature starts to rise, but air pressure continues to fall. This is the beginning of the [[w:ionosphere|ionosphere]], a region dominated by chemical ions. Many of them are the same chemicals such as [[w:nitrogen|nitrogen]] and [[w:oxygen|oxygen]] in the atmosphere below, but an ever increasing number are hydrogen ions ([[w:proton|proton]]s) and helium ions. These can be detected by an ion spectrometer. The process of [[w:ionization|ionization]] removes one or more [[w:electron|electron]]s from a neutral atom to yield a variety of ions depending on the chemical element species and incidence of sufficient energy to remove the electrons. '''Def.''' the "part of the Earth's atmosphere beginning at an altitude of about 50 kilometers [31 miles] and extending outward 500 kilometers [310 miles] or more"<ref name=IonosphereWikt>{{ cite web |author=[[wikt:User:CORNELIUSSEON|CORNELIUSSEON]] |title=ionosphere |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=11 June 2006 |url=https://en.wiktionary.org/wiki/ionosphere |accessdate=2012-09-20 }}</ref> or the "similar region of the atmosphere of another planet"<ref name=IonosphereWikt1>{{ cite web |author=[[wikt:User:RJFJR|RJFJR]] |title=ionosphere |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=15 November 2008 |url=https://en.wiktionary.org/wiki/ionosphere |accessdate=2012-09-20 }}</ref> is called an '''ionosphere'''. "As a spacecraft travels through the solar system, a targeted radio signal sent back to Earth can be aimed through the ionosphere of a nearby planet. Plasma in the ionosphere causes small but detectable changes in the signal that allow scientists to learn about the upper atmosphere."<ref name=Redd>{{ cite web |author=Nola Taylor Redd |title=Meteoroids Change Atmospheres of Earth, Mars, Venus |publisher=Space.com |location= |date=September 4, 2012 |url=http://www.space.com/17440-meteoroids-mars-venus-atmospheres.html |accessdate=2012-09-05 }}</ref> {{clear}} ==Io plasma torus== {{main|Plasmas/Plasma objects/Io}} [[Image:Jupiter magnetosphere schematic.jpg|thumb|right|250px|This is a schematic of Jupiter's magnetosphere and the components influenced by Io (near the center of the image). Credit: John Spencer.]] The image at right represents "[t]he Jovian magnetosphere [magnetic field lines in blue], including the Io flux tube [in green], Jovian aurorae, the sodium cloud [in yellow], and sulfur torus [in red]."<ref name=Spencer>{{ cite book |author=John Spencer |title=John Spencer's Astronomical Visualizations |publisher=University of Colorado |location=Boulder, Colorado USA |date=November 2000 |url=http://www.boulder.swri.edu/~spencer/digipics.html |accessdate=2013-04-05 }}</ref> "Io may be considered to be a unipolar generator which develops an emf [electromotive force] of 7 x 10⁵ volts across its radial diameter (as seen from a coordinate frame fixed to Jupiter)."<ref name=Goldreich>{{ cite journal |author=Peter Goldreich |author2=Donald Lynden-Bell |title=Io, a jovian unipolar inductor |journal=The Astrophysical Journal |month=April |year=1969 |volume=156 |issue=04 |pages=59-78 |url= |arxiv= |bibcode=1969ApJ...156...59G |doi=10.1086/149947 |pmid= |accessdate=2013-04-05 }}</ref> "This voltage difference is transmitted along the magnetic flux tube which passes through Io. ... The current [in the flux tube] must be carried by keV electrons which are electrostatically accelerated at Io and at the top of Jupiter's ionosphere."<ref name=Goldreich/> "Io's high density (4.1 g cm^-3) suggests a silicate composition. A reasonable guess for its electrical conductivity might be the conductivity of the Earth's upper mantle, 5 x 10^-5 ohm^-1 cm^-1 (Bullard 1967)."<ref name=Goldreich/> As "a conducting body [transverses] a magnetic field [it] produces an induced electric field. ... The Jupiter-Io system ... operates as a unipolar inductor" ... Such unipolar inductors may be driven by electrical power, develop hotspots, and the "source of heating [may be] sufficient to account for the observed X-ray luminosity".<ref name=Wu>{{ cite journal |author=Kinwah Wu |author2=Mark Cropper |author3=Gavin Ramsay |author4=Kazuhiro Sekiguchi |title=An electrically powered binary star? |journal=Monthly Notices of the Royal Astronomical Society |month=March |year=2002 |volume=321 |issue=1 |pages=221-7 |url= |arxiv=astro-ph/0111358 |bibcode=2002MNRAS.331..221W |doi=10.1046/j.1365-8711.2002.05190.x |pmid= |accessdate=2013-04-05 }}</ref> "The electrical surroundings of Io provide another energy source which has been estimated to be comparable with that of the [gravitational] tides (7). A current of 5 x 10⁶ A is ... shunted across flux tubes of the Jovian field by the presence of Io (7-9)."<ref name=Gold>{{ cite journal |author=Thomas Gold |title=Electrical Origin of the Outbursts on Io |journal=Science |month=November |year=1979 |volume=206 |issue=4422 |pages=1071-3 |url= |arxiv= |bibcode=1979Sci...206.1071G |doi=10.1126/science.206.4422.1071 |pmid= |accessdate=2013-04-05 }}</ref> "[W]hen the currents [through Io] are large enough to cause ohmic heating ... currents ... contract down to narrow paths which can be kept hot, and along which the conductivity is high. Tidal heating [ensures] that the interior of Io has a very low eletrical resistance, causing a negligible extra amount of heat to be deposited by this current. ... [T]he outermost layers, kept cool by radiation into space [present] a large resistance and [result in] a concentration of the current into hotspots ... rock resistivity [and] contact resistance ... contribute to generate high temperatures on the surface. [These are the] conditions of electric arcs [that can produce] temperatures up to ionization levels ... several thousand kelvins".<ref name=Gold/> "[T]he outbursts ... seen [on the surface may also be] the result of the large current ... flowing in and out of the domain of Io ... Most current spots are likely to be volcanic calderas, either provided by tectonic events within Io or generated by the current heating itself. ... [A]s in any electric arc, very high temperatures are generated, and the locally evaporated materials ... are ... turned into gas hot enough to expand at a speed of 1 km/s."<ref name=Gold/> {{clear}} ==Local hot bubbles== [[Image:Local_bubble.jpg|thumb|right|250px|The Local Hot Bubble is hot X-ray emitting gas within the Local Bubble pictured as an artist's impression. Credit: NASA.]] The 'local hot bubble' is a "hot X-ray emitting plasma within the local environment of the Sun."<ref name=Kappes>{{ cite journal |author=M. Kappes |author2=J. Kerp |author3=P. Richter |title=The composition of the interstellar medium towards the Lockman Hole H I, UV and X-ray observations |journal=Astronomy and Astrophysics |month=July |year=2003 |volume=405 |issue=7 |pages=607-16 |url= |arxiv= |bibcode=2003A&A...405..607K |doi=10.1051/0004-6361:20030610 |pmid= |accessdate=2012-01-19 }}</ref> "This coronal gas fills the irregularly shaped local void of matter (McCammon & Sanders 1990) - frequently called the Local Hot Bubble (LHB)."<ref name=Kappes/> "The [X-ray] intensity of the [Local Hot Bubble] LHB varies across the entire sky:"<ref name=Kerp>{{ cite journal |author=J. Kerp |author2=W. B. Burton |author3=R. Egger |author4=M.J. Freyberg |author5=Dap Hartmann |author6=P.M.W. Kalberla |author7=U. Mebold |author8=J. Pietz |title=A search for soft X-ray emission associated with prominent high-velocity-cloud complexes |journal=Astronomy and Astrophysics |month=February |year=1999 |volume=342 |issue=02 |pages=213-32 |url=http://arxiv.org/abs/astro-ph/9810307 |arxiv=astro-ph/9810307 |bibcode=1999A&A...342..213K |doi= |pmid= |accessdate=2013-07-11 }}</ref> : ''I''_LHB = (2.5-8.2) x 10^-4 cts s^-1 arcmin^-2 (Snowden et al. 1998). The galactic X-ray background is produced largely by emission from the Local Hot Bubble which is within 100 parsecs of the Sun. The Local Hot Bubble is within the [[w:Local Bubble|Local Bubble]]. {{clear}} ==Magnetic clouds== A '''magnetic cloud''' is a transient event observed in the [[w:solar wind|solar wind]]. It was defined in 1981 by Burlaga et al. 1981 as a region of enhanced [[w:magnetic field|magnetic field]] strength, smooth rotation of the magnetic field vector and low [[w:proton|proton]] temperature <ref name=Burlaga>Burlaga, L. F., E. Sittler, F. Mariani, and R. Schwenn, "Magnetic loop behind an interplanetary shock: Voyager, Helios and IMP-8 observations" in "Journal of Geophysical Research", 86, 6673, 1981</ref>. Magnetic clouds are a possible manifestation of a [[w:Coronal Mass Ejection|Coronal Mass Ejection]] (CME). The association between CMEs and magnetic clouds was made by Burlaga et al. in 1982 when a magnetic cloud was observed by [[w:Helios probes|Helios-1]] two days after being observed by [[w:Solar Maximum Mission|SMM]]<ref name=Burlaga82>Burlaga, L. F. et al., "A magnetic cloud and a coronal mass ejection" in "Geophysical Research Letter"s, 9, 1317-1320, 1982</ref>. However, because observations near Earth are usually done by a single spacecraft, many CMEs are not seen as being associated with magnetic clouds. The typical structure observed for a fast CME by a satellite such as [[w:Advanced Composition Explorer|ACE]] is a fast-mode [[w:shock wave|shock wave]] followed by a dense (and hot) sheath of plasma (the downstream region of the shock) and a magnetic cloud. Other signatures of magnetic clouds are now used in addition to the one described above: among other, bidirectional superthermal electrons, unusual charge state or abundance of iron, helium, carbon and/or oxygen. The typical time for a magnetic cloud to move past a satellite at the [[w:Lagrange Point|L1]] point is 1 day corresponding to a radius of 0.15 [[w:Astronomical Unit|AU]] with a typical speed of 450&nbsp;km s⁻¹ and magnetic field strength of 20 nT <ref name=Lepping>Lepping, R. P. et al. "Magnetic field structure of interplanetary magnetic clouds at 1 AU" in "Journal of Geophysical Research", 95, 11957-11965, 1990.</ref> ==Magnetic reconnections== Magnetic reconnection is a physical process in highly conducting plasmas in which the magnetic [[w:topology|topology]] is rearranged and magnetic energy is converted to [[w:kinetic energy|kinetic energy]], [[w:thermal energy|thermal energy]], and [[w:particle acceleration|particle acceleration]]. Magnetic reconnection occurs on timescales intermediate between slow resistive diffusion of the [[w:magnetic field|magnetic field]] and fast [[w:Alfven wave|Alfvénic]] timescales. The qualitative description of the reconnection process is such that magnetic field lines from different [[w:magnetic domain|magnetic domain]]s (defined by the field line connectivity) are spliced to one another, changing their patterns of connectivity with respect to the sources. It is a violation of an approximate conservation law in plasma physics, and can concentrate mechanical or magnetic energy in both space and time. ==Magnetospheres== A '''magnetosphere''' is formed when a stream of charged particles, such as the solar wind, interacts with and is deflected by the magnetic field of a planet or similar body. “Planets which generate magnetic fields in their interiors ... are surrounded by invisible magnetospheres. ... [I]n many respects, the magnetosphere of Venus is a scaled-down version of Earth’s. ... Earth’s magnetosphere is 10 times larger [than that of Venus]”<ref name=Zhang>{{ cite book |author=Tielong Zhang |author2=Håkan Svedhem |title=A magnetic surprise for Venus Express |publisher=European Space Agency |location=The Netherlands |date=April 5, 2012 |url=http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=50246 |accessdate=2012-04-07 }}</ref> ==Microflares== Ultraviolet telescopes such as [[w:TRACE|TRACE]] and [[w:Solar and Heliospheric Observatory|SOHO]]/EIT can observe individual [solar] micro-flares as small brightenings in extreme ultraviolet light.<ref name=Patsourakos>{{ cite journal | doi = 10.1051/0004-6361:20020151 | author =S. Patsourakos, J.-C. Vial | title = Intermittent behavior in the transition region and the low corona of the quiet Sun | journal = Astronomy and Astrophysics | volume = 385 | pages = 1073–1077 | year = 2002 | bibcode=2002A&A...385.1073P }}</ref> ==Nanoflares== [[Image:378877main Nanoflares lg.jpg|thumb|right|250px|"This false-color temperature map shows solar active region AR10923, observed close to center of the sun's disk. Blue regions indicate plasma near 10 million degrees K." Credit: Reale, et al. (2009), NASA.]] The image at the right shows the first detection of high temperature nanoflares. The false-color temperature map of solar active region AR10923, observed close to center of the sun's disk, contains nanoflare regions (blue, indicating plasma near 10 million degrees K). "Nanoflares are small, sudden bursts of heat and energy. "They occur within tiny strands that are bundled together to form a magnetic tube called a coronal loop," says Klimchuk. Coronal loops are the fundamental building blocks of the thin, translucent gas known as the sun's [[Coronal cloud|corona]]. ... Observations from the NASA-funded X-Ray Telescope (XRT) and Extreme-ultraviolet Imaging Spectrometer (EIS) instruments aboard Hinode reveal that ultra-hot plasma is widespread in solar active regions. The XRT measured plasma at 10 million degrees K, and the EIS measured plasma at 5 million degrees K. "These temperatures can only be produced by impulsive energy bursts,"says Klimchuk ... "Coronal loops are bundles of unresolved strands that are heated by storms of nanoflares." ... when a nanoflare suddenly releases its energy, the plasma in the low-temperature, low-density strands becomes very hot—around 10 million degrees K—very quickly. The density remains low, however, so the emission, or brightness, remains faint. Heat flows from up in the strand, where it's hot, down to the base of the coronal loop, where it's not as hot. This heats up the dense plasma at the loop’s base. Because it is so dense at the base, the temperature only reaches about 1 million degrees K. This dense plasma expands up into the strand. Thus, a coronal loop is a collection of 5-10 million degree K faint strands and 1 million degree K bright strands. "What we see is 1 million degree K plasma that has received its energy from the heat flowing down from the superhot plasma," says Klimchuk. "For the first time, we have detected this 10 million degree plasma, which can only be produced by the impulsive energy bursts of nanoflares.""<ref name=Layton2009>{{ cite web |author=Laura Layton |title=Tiny Flares Responsible for Outsized Heat of Sun's Atmosphere |publisher=NASA GSFC |location=Greenbelt, Maryland, USA |date=August 14, 2009 |url=http://www.nasa.gov/topics/solarsystem/features/nanoflares.html |accessdate=2012-11-18 }}</ref> The idea that nanoflares might heat the corona was put forward by [[w:Eugene Parker|Eugene Parker]] in the 1980s but is still controversial. In particular, ultraviolet telescopes such as [[w:TRACE|TRACE]] and [[w:Solar and Heliospheric Observatory|SOHO]]/EIT can observe individual micro-flares as small brightenings in extreme ultraviolet light,<ref name=Patsourakos/> but there seem to be too few of these small events to account for the energy released into the corona. The additional energy not accounted for could be made up by wave energy, or by gradual magnetic reconnection that releases energy more smoothly than micro-flares and therefore doesn't appear well in the TRACE data. Variations on the micro-flare hypothesis use other mechanisms to stress the magnetic field or to release the energy, and are a subject of active research in 2005. A nanoflare is a very small [[w:solar flare|solar flare]] which happens in the [[w:corona|corona]], the external [[w:atmosphere|atmosphere]] of the [[Stars/Sun|Sun]]. Observations show that the [[w:solar magnetic field|solar magnetic field]], which is frozen into the motion of the [[w:Plasma (physics)|plasma]] opens into semicirculal structures in the corona. These [[w:coronal loops|coronal loops]], which can be seen in the EUV and X-ray images (see the figure on the left), confine very hot plasma, emitting as it were at a temperature of a few million degrees. Many flux tubes are stable for several days on the solar corona in the X-ray images, emitting at steady rate. However flickerings, brightenings, small explosions, bright points, flares and mass eruptions are observed very frequently, especially in [[w:stellar active region|active regions]]. These macroscopic signs of solar activity are considered by astrophysicists as the phenomenology related to events of relaxation of stressed magnetic fields, during which part of the coronal heating is released by current dissipation or [[w:Joule effect|Joule effect]]. These nanoflares might be very tiny flares, so close one to each other, both in time and in space, to heat the corona and to cause all the phenomena due to solar activity. The distribution of the number of flares observed in the hard X-rays is a function of the energy, following a power law with negative spectral index 1.8.<ref name=Datlowe>{{ cite journal | author = D.W. Datlowe |author2=M.J.Elean |author3=H.S. Hudson | title =OSO-7 observations of solar x-rays in the energy range 10?100 keV | journal = Solar Physics | volume = 39 | pages = 155 | year = 1974 | doi = 10.1007/BF00154978 | bibcode=1974SoPh...39..155D }}</ref><ref name=Lin>{{ cite journal |author=Lin R.P. |author2=Schwartz R.A. |author3=Kane S.R. |author4=Pelling R.M. |author5=Hurley K.C. | journal= The Astrophysical Journal | volume= 283 | pages= 421 |doi=10.1086/162321 |title=Solar hard X-ray microflares | bibcode=1984ApJ...283..421L }}</ref><ref name=Dennis>{{ cite journal |author=Brian R. Dennis | year= 1985 | journal= Solar Physics | volume= 100 | pages= 465 |doi=10.1007/BF00158441 |title=Solar hard X-ray bursts | bibcode=1985SoPh..100..465D }}</ref> <ref name=Porter>{{ cite journal | author=Porter J.G. |author2=Fontenla J.M. |author3=Simnett G.M. |journal= The Astrophysical Journal | volume= 438 |pages= 472 | doi=10.1086/175091 | title=Simultaneous ultraviolet and X-ray observations of solar microflares | bibcode=1995ApJ...438..472P }}</ref> If this distribution would have the same spectral index also at lower energies, flares, micro-flares and nanoflares might provide a considerable part of coronal heating. Actually a negative spectral index of the order of 2 is required in order to maintain the [[w:solar corona|solar corona]]. "[T]he importance of the magnetic field is recognized by all the scientists: there is a strict correspondence between the [[w:stellar active region|active regions]], where the irradiated flux is higher (especially in the X-rays), and the regions of intense magnetic field.<ref name=Poletto>{{ cite journal |author=Poletto G |author2=Vaiana GS |author3=Zombeck MV |author4=Krieger AS |author5=Timothy AF |title=A comparison of coronal X-ray structures of active regions with magnetic fields computed from photospheric observations |journal=Solar Physics |date=September 1975 |volume=44 |issue=9 |pages=83–99 |doi=10.1007/BF00156848 |bibcode=1975SoPh...44...83P }}</ref> More energy is released in turbulent regimes when nanoflares happen at much smaller scale-lengths, where non-linear effects are not negligible.<ref name=Rappazzo>{{ cite journal |author= Rappazzo, A. F. |author2=Velli, M. |author3=Einaudi, G. |author4=Dahlburg, R. B. |title=Nonlinear Dynamics of the Parker Scenario for Coronal Heating |journal=The Astrophysical Journal 2008 |volume=677 |issue= 2 |pages= 1348–1366 |bibcode=2008ApJ...677.1348R |doi= 10.1086/528786 }}</ref> In order to heat a region of very high [[w:X-ray|X-ray]] emission, over an area 1" x 1", a nanoflare of 10¹⁷ J should happen every 20 seconds, and 1000 nanoflares per second should occur in a large active region of 10⁵ x 10⁵ km². Flickerings, brightenings, small explosions, bright points, flares and mass eruptions are observed very frequently, especially in [[stellar active region|active regions]]. {{clear}} ==Nova-like stars== {{main|Stars/Nova-likes}} The evolution of non-magnetic dwarf novae and nova-like stars can be different from the magnetic systems (polars and intermediate polars).<ref name=Ak/> Magnetic and non-magnetic systems display different kinematical properties since some flow velocities come from magnetically channeled plasma.<ref name=Ak>{{ cite journal |author=T Ak T |author2=S Bilir |author3=S Ak |author4=KB Coskunoglu |author5=Z Eker |title=The age of cataclysmic variables: a kinematic study |journal=New Astronomy |month=August |year=2010 |volume=15 |issue=6 |pages=491-508 |url=http://adsabs.harvard.edu/abs/2010NewA...15..491A |arxiv=0911.3651 |bibcode=2010NewA...15..491A |doi=10.1016/j.newast.2009.11.007 |pmid= |accessdate=2016-09-30 }}</ref> ==Photospheres== The solar photosphere is a "weakly ionized [''n''_i/(''n''_i + ''n''_a)] ~ 10^-4, relatively cold and dense plasma".<ref name=Khodachenko>{{ cite journal |author=M. L. Khodachenko |author2=V. V. Zaitsev |title=Formation of Intensive Magnetic Flux Tubes in a Converging Flow of Partially Ionized Solar Photospheric Plasma |journal=Astrophysics and Space Science |month=March 01, |year=2002 |volume=279 |issue=4 |pages=389-410 |url=http://link.springer.com/article/10.1023/A:1015162131331 |arxiv= |bibcode= |doi=10.1023/A:1015162131331 |pmid= |accessdate=2013-07-17 }}</ref> ==Plages== A '''plage''' is a bright region in the [[w:chromosphere|chromosphere]] of [a star], typically found in regions of the chromosphere near [starspots]. The plage regions map closely to the [[w:faculae|faculae]] in the photosphere below, but the latter have much smaller spatial scales. Accordingly plage occurs most visibly near a starspot region. "Plages are formed in the inner parts of flux loops emerging from below. ... In the early stages of active region growth the appearance of the group is symmetric, while a few days later the ''f'' spot may disappear, leaving an extensive plage."<ref name=Zirin1974>{{ cite book |author=H. Zirin |title=The Magnetic Structure of Plages, In: ''Chromospheric Fine Structure'' |publisher=International Astronomical Union |location=Dordrecht |year=1974 |editor=R. Grant Athay |pages=161-75 |url= |arxiv= |bibcode=1974IAUS...56..161Z |doi= |pmid= |isbn= }}</ref> "[M]ajor changes in active regions only take place in the following ways: # [starspot] formation and break up; # flux outflow from [starspots]; # new flux emergence; and # magnetic reconnection."<ref name=Zirin1974/> "In general there is no proper motion at all in the plage or the surrounding plagettes except for the latter two."<ref name=Zirin1974/> ==Plasma objects== {{main|Plasmas/Plasma objects|Plasma objects}} '''Plasma''' is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms (reduce or increase the number of electrons in them), thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions.<ref name=Luo>{{ cite journal |author=Q-Z Luo |author2=N. D'Angelo |author3=R. L. Merlino | year=1998 |title=Shock formation in a negative ion plasma |journal= |volume=5 |issue=8 |publisher=Department of Physics and Astronomy |url=http://www.physics.uiowa.edu/~rmerlino/nishocks.pdf |accessdate=2011-11-20}}</ref> For plasma to exist, ionization is necessary. The term "plasma density" by itself usually refers to the "electron density", that is, the number of free electrons per unit volume. The degree of ionization of a plasma is the proportion of atoms that have lost or gained electrons, and is controlled mostly by the temperature. Even a partially ionized gas in which as little as 1% of the particles are ionized can have the characteristics of a plasma (i.e., response to magnetic fields and high electrical conductivity). The degree of ionization, ''α'' is defined as ''α'' = ''n''_i/(''n''_i + ''n''_a) where ''n''_i is the number density of ions and ''n''_a is the number density of neutral atoms. The ''electron density'' is related to this by the average charge state <Z> of the ions through ''n''_e = <Z> ''n''_i where ''n''_e is the number density of electrons. "Plasma is the fourth state of matter, consisting of electrons, ions and neutral atoms, usually at temperatures above 10⁴ degrees Kelvin."<ref name=Birdsall>{{ cite book |author=CK Birdsall, A. Bruce Langdon |title=Plasma Physics via Computer Simulation |publisher=CRC Press |location=New York |date=1 October 2004 |editor= |pages=479 |url=http://books.google.com/books?hl=en&lr=&id=S2lqgDTm6a4C&oi=fnd&pg=PR13&ots=nOPXyqtDo8&sig=-kA8YfaX6nlfFnaW3CYkATh-QPg |arxiv= |bibcode= |doi= |pmid= |isbn=9780750310253 |accessdate=2011-12-17 }}</ref> "The sun and stars are plasmas; the earth's ionosphere, Van Allen belts, magnetosphere, etc., are all plasmas. Indeed, plasma makes up much of the known matter in the universe."<ref name=Birdsall/> ==Plasma rains== "Hot plasma in the corona cooled and condensed along strong magnetic fields in the region" slowly falling back to the solar surface as plasma "rain".<ref name=WallRain/> {{clear}} ==Prominences== [[Image:Sunflare skylab4 big.jpg|thumb|right|250px|A major eruptive prominence is imaged by Skylab in 1973. Credit: [http://www.ksc.nasa.gov/history/skylab/skylab.html Skylab], NASA.]] [[Image:Detached sola prominence.jpg|thumb|right|250px|This shows a detached Solar prominence. Credit: [https://sites.google.com/site/thebrockeninglory/ Brocken Inaglory].]] A '''prominence''' is a large, bright feature extending outward from [a star's] surface, often in a [[w:Coronal loops|loop]] shape. Prominences are anchored to [a star's] surface in the [[w:photosphere|photosphere]], and extend outwards into the [star's] [[Coronal cloud|corona]]. While the corona consists of extremely hot ionized gases, known as [[w:Plasma (physics)|plasma]], which [does] not emit much visible light, prominences contain much cooler plasma, similar in composition to that of the [[w:chromosphere|chromosphere]]. A prominence forms over timescales of about a day, and stable prominences may persist in the corona for several months. Some prominences break apart and give rise to [[w:coronal mass ejection|coronal mass ejection]]s. A typical prominence extends over many thousands of kilometers; the largest on record was estimated at over 800,000 kilometres (500,000 mi) long<ref name="univtoday">{{ cite book |url=http://www.universetoday.com/96649/huge-solar-filament-stretches-across-the-sun/ |title=Huge Solar Filament Stretches Across the Sun |author=Nancy Atkinson |work=Universe Today |date=August 6, 2012 |accessdate=August 11, 2012 }}</ref> – roughly the radius of the Sun. "When a prominence is viewed from a different perspective so that it is against the [star] instead of against space, it appears darker than the surrounding background. This formation is instead called a [stellar] filament.<ref name="univtoday" /> It is possible for a projection to be both a filament and a prominence. Some prominences are so powerful that they throw out matter from the [star] into space at speeds ranging from 600&nbsp;km/s to more than 1000&nbsp;km/s. Other prominences form huge loops or arching columns of glowing gases over [starspots] that can reach heights of hundreds of thousands of kilometres. Prominences may last for a few days or even for a few months.<ref>{{ cite book | url=http://solar.physics.montana.edu/ypop/Program/hfilament.html | title=About Filaments and Prominences | accessdate=2010-01-02 }}</ref> Flocculi (plural of flocculus) is another term for these filaments, and dark flocculi typically describes the appearance of [stellar] prominences when viewed against the [stellar] disk in certain wavelengths. {{clear}} ==Regions== {{main|Regions/Astronomy}} [[Image:LASCO C1 coronagraph of solar corona.png‎|right|thumb|250px|A picture of the solar corona is taken with the [[w:LASCO|LASCO]] C1 coronagraph. The image is color coded for the doppler shift of the FeXIV 530.8 nm line. Credit: NASA and NRL.]] The preflare solar material is observed "to be an elevated cloud of prominence-like material which is suddenly lit up by the onslaught of hard electrons accelerated in the flare; the acceleration may be inside or outside the cloud, and brightening is seen in other areas of the solar surface on the same magnetic field lines."<ref name=Zirin78>{{ cite journal |author=Harold Zirin |title=The L-alpha/H-alpha ratio in solar flares, quasars, and the chromosphere |journal=Astrophysical Journal |month=June |year=1978 |volume=222 |issue=6 |pages=L105-7 |url= |bibcode=1978ApJ...222L.105Z |doi= 10.1086/182702 |pmid= |accessdate=2011-08-01 }}</ref> "A hot coronal cloud at ''T'' ~ 10⁷ K is left behind, presumably evaporated from the original material."<ref name=Zirin78/> "[O]nce ionized, the gas is rapidly heated by Coulomb collisions to the coronal cloud temperature, but as this material peels off, a cooler hydrogen-emitting region is left."<ref name=Zirin78/> Regions which are not in [[w:coronal hole|coronal hole]]s are "called 'coronal cloud' regions after their appearance in photographs of the Sun taken in soft X-rays, which most dramatically show up coronal holes."<ref name=McWhirter>{{ cite journal |author=McWhirter R. W. P. |author2=Kopp R. A. |title=The energy balance in the solar atmosphere above coronal holes |journal=Royal Astronomical Society, Monthly Notices |month=September |year=1979 |volume=188 |issue=9 |pages=871-81 |url= |bibcode=1979MNRAS.188..871M |doi= |pmid= |accessdate=2011-08-01 }}</ref> These 'coronal cloud' regions are "in fact the majority of the solar surface."<ref name=McWhirter/> Lying at a level above the 10⁴ K isotherm, "the thermally conducted flux is negligible, and bounded by the magnetic surfaces between open field (coronal hole) and closed field (coronal cloud) regions."<ref name=McWhirter/> "[C]oronal cloud regions produce no solar wind," but "[s]ome of the input energy may pass out of the cloud regions into the region where the wind is accelerated, thereby contributing to this process."<ref name=McWhirter/> In the image at right the iron (Fe XIV) green line is followed by doppler imaging to show associated relative coronal plasma velocity towards (-7 km/s side) and away from (+7 km/s side) the large angle spectrometric coronagraph [[w:LASCO|LASCO]] satellite camera. {{clear}} ==Starquakes== [[Image:MoretonWaveAnimation200612.gif|thumb|right|250px|This is an animation of a Moreton wave which occurred on the Sun at December 6, 2006. Credit: National Solar Observatory (NSO)/AURA/NSF and USAF Research Laboratory.]] [[Image:Solar tsunami.jpg|thumb|250px|right|This image shows a solar tsunami on May 19, 2007. Credit: NASA/STEREO/EUVI consortium.]] "The phenomenon of flare induced sunquakes - waves in the photosphere - discovered by Kosovichev and Zharkova (1998) and now widely studied (e.g. Kosovichev 2006) should also result from the momentum impulse delivered by a cometary impact."<ref name=Brown>{{ cite journal |author=J.C. Brown |author2=H.E. Potts |author3=L.J. Porter |author4=G.le Chat |title=Mass Loss, Destruction and Detection of Sun-grazing & -impacting Cometary Nuclei |journal=Astronomy & Astrophysics |date=November 8, 2011 |volume=535 |issue= |pages=12 |url=http://www.aanda.org/articles/aa/abs/2011/11/aa15660-10/aa15660-10.html |arxiv= |bibcode= |doi=10.1051/0004-6361/201015660 |pmid= |pdf=http://arxiv.org/pdf/1107.1857.pdf |accessdate=2012-11-25 }}</ref> A '''Moreton wave''' is the [[w:chromosphere|chromospheric]] signature of a large-scale solar [[Coronal cloud|coronal]] [[w:shock wave|shock wave]]. Described as a kind of [[Stars/Sun|solar]] '[[w:tsunami|tsunami]]',<ref name="tphill09">{{ cite book |author=Tony Phillips |title=Monster Waves on the Sun are Real |url=http://science.nasa.gov/science-news/science-at-nasa/2009/24nov_solartsunami/ |publisher=NASA |accessdate=16 July 2010 |date=November 24, 2009 }}</ref> they are generated by solar flares<ref name=Moreton>{{ cite journal |author=G. E. Moreton |title=Hα Observations of Flare-Initiated Disturbances with Velocities ~1000 km/sec |journal=Astronomical Journal |volume=65 |issue= |pages=494 |year=1960 |doi=10.1086/108346 |bibcode=1960AJ.....65U.494M }}</ref><ref name=Moreton60>{{ cite journal |author=G. E. Moreton, H. E. Ramsey |title=Recent Observations of Dynamical Phenomena Associated with Solar Flares |journal=Publications of the Astronomical Society of the Pacific |volume=72 |issue=428 |pages=357 |year=1960 |doi=10.1086/127549 |bibcode=1960PASP...72..357M }}</ref><ref name=Athay61>{{ cite journal |author=R. Grant Athay, Gail E. Moreton |title=Impulsive Phenomena of the Solar Atmosphere. I. Some Optical Events Associated with Flares Showing Explosive Phase |journal=The Astrophysical Journal |year=1961 |volume=133 |issue= |pages=935 |doi=10.1086/147098 |bibcode=1961ApJ...133..935A }}</ref>. The 1995 launch of the [[w:Solar and Heliospheric Observatory|Solar and Heliospheric Observatory]] led to observation of coronal waves, which cause Moreton waves. (SOHO's [[w:Extreme ultraviolet Imaging Telescope|EIT]] instrument discovered another, different wave type called 'EIT waves'.)<ref name=Chen>{{ cite journal |url=http://solar.physics.montana.edu/nuggets/2002/020208/020208.html |title=Moreton waves and coronal waves |journal=The Astrophysical Journal |volume=572 |issue= |pages=L99–L102 |year=2002 |bibcode = 2002ApJ...572L..99C |doi = 10.1086/341486 |author=P. F. Chen |author2=S. T. Wu |author3=K. Shibata |author4=C. Fang }}</ref> The reality of Moreton waves (aka fast-mode [[w:Magnetohydrodynamics|MHD]] waves) has also been confirmed by the two [[w:STEREO|STEREO]] spacecraft. They observed a 100,000-km-high wave of hot plasma and magnetism, moving at 250&nbsp;km/second, in conjunction with a big coronal mass ejection in February 2009.<ref name=Atkins>{{ cite book |author=William Atkins |title=STEREO spacecraft finds gigantic tsunami on Sun |url=http://www.itwire.com/science-news/space/29658-stereo-spacecraft-finds-gigantic-tsunami-on-sun |publisher=iTWire |accessdate=16 July 2010 |date=26 November 2009 }}</ref><ref name="pho111909">{{ cite book |title=Mystery of the Solar Tsunami -- Solved |url=http://www.physorg.com/news177872248.html |publisher=PhysOrg.com |accessdate=16 July 2010 |author=JPL/NASA |date=November 19, 2009 }}</ref> Moreton waves propagate at a speed of usually 500–1500&nbsp;km/s. [[w:Yutaka Uchida|Yutaka Uchida]] interpreted Moreton waves as MHD fast mode shock waves propagating in the corona.<ref name=Sakurai2002>{{ cite book |author=Takashi Sakurai |title=SolarNews Newsletter |url=http://spd.aas.org/SolarNews/archive/news.2002/19.sep |publisher=Solar Physics Division, American Astronomical Society |accessdate=15 June 2011 |date=3 September 2002 }}</ref> He links them to [[w:type II radio bursts|type II radio bursts]], which are radio wave discharges created when coronal mass ejections accelerate shocks.<ref name=Layton>{{ cite book |author=Laura Layton |title=STEREO Spies First Major Activity of Solar Cycle 24 |url=http://www.nasa.gov/mission_pages/stereo/news/solarcycle24.html |publisher=NASA |accessdate=15 June 2011 |date=May 15, 2009 }}</ref> Moreton waves can be observed primarily in the [[w:Hα|Hα]] band.<ref name="Narukage, et al.">{{ cite journal |author=N. Narukage |author2=Shigeru |author3=Miwako Kadota |author4=Reizaburo Kitai |author5=Hiroki Kurokawa |author6=Kazunari Shibata |year=2004 |title=Moreton waves observed at Hida Observatory |journal = Proceedings IAU Symposium |issue = 223 |pages = 367–370 |doi=10.1017/S1743921304006143 |url=http://journals.cambridge.org/production/action/cjoGetFulltext?fulltextid=288483 |accessdate = 2006-12-11 |volume = 2004 }}</ref> {{clear}} ==Stellar cycles== [[Image:Sunspot_butterfly_graph.gif|thumb|200px|right|The [[w:Butterfly diagram|butterfly diagam]] shows paired sunspot pattern. The graph is of sunspot [[w:Wolf number|Wolf number]] versus time. Credit: .]] The solar cycle has a great influence on [[w:space weather|space weather]], and a significant influence on the Earth's climate since the Sun's luminosity has a direct relationship with magnetic activity.<ref name=Wilson>{{ cite journal |author=R. C. Willson, H. S. Hudson |year=1991 |title=The Sun's luminosity over a complete solar cycle |journal=Nature |volume=351 |issue=6321 |pages=42–4 |doi=10.1038/351042a0 |bibcode = 1991Natur.351...42W }}</ref> Solar activity minima tend to be correlated with colder temperatures, and longer than average solar cycles tend to be correlated with hotter temperatures. In the 17th century, the solar cycle appeared to have stopped entirely for several decades; few sunspots were observed during this period. During this era, known as the [[w:Maunder minimum|Maunder minimum]] or [[w:Little Ice Age|Little Ice Age]], Europe experienced unusually cold temperatures.<ref name="Lean">{{ cite journal |last=Lean |first=J. |last2=Skumanich |first2=A. |last3=White |first3=O. |year=1992 |title=Estimating the Sun's radiative output during the Maunder Minimum |journal=Geophysical Research Letters |volume=19 |issue=15 |pages=1591–1594 |doi=10.1029/92GL01578 |ref=harv |bibcode=1992GeoRL..19.1591L }}</ref> Earlier extended minima have been discovered through analysis of [[w:tree ring|tree ring]]s and appear to have coincided with lower-than-average global temperatures.<ref name=Mackay>{{ cite book |author=R. M. Mackay, M. A. K. Khalil |title=Greenhouse gases and global warming, In: ''Trace Gas Emissions and Plants'' |url= http://books.google.com/?id=tQBS3bAX8fUC&pg=PA1 |editor=S. N. Singh |year=2000 |pages=1–28 |publisher=Springer |isbn=978-0-7923-6545-7 }}</ref> "MOST current literature on solar activity assumes that the planets do not affect it, and that conditions internal to the Sun are primarily responsible for the solar cycle. Bigg¹, however, has shown that the period of Mercury's orbit appears in the sunspot data, and that the influence of Mercury depends on the phases of Venus, Earth, and Jupiter."<ref name=Wood>{{ cite journal |author=K. D. Wood |title=Physical Sciences: Sunspots and Planets |journal=Nature |month=November 10, |year=1972 |volume=240 |issue=5376 |pages=91-3 |url=http://www.nature.com/nature/journal/v240/n5376/abs/240091a0.html |arxiv= |bibcode=1972Natur.240...91W |doi=10.1038/240091a0 |pmid= |accessdate=2013-07-07 }}</ref> "It is shown that starting with the alignment of Venus with Jupiter at perihelion position, these two planets will perfectly align at Jupiter's perihelion after every 23.7 years".<ref name=Verma>{{ cite book |author=S.D. Verma |title=Influence of Planetary Motion and Radial Alignment of Planets on Sun, In: ''Space Dynamics and Celestial Mechanics'' |publisher=Springer Netherlands |location= |year=1986 |editor=K. B. Bhatnagar |volume=127 |issue= |pages=143-54 |url=http://link.springer.com/chapter/10.1007/978-94-009-4732-0_13 |arxiv= |bibcode= |doi=10.1007/978-94-009-4732-0_13 |pmid= |isbn=978-94-010-8603-5 |accessdate=2013-07-07 }}</ref> "The tidal forces hypothesis for solar cycles has been proposed by Wood (1972) and others. Table 2 below shows the relative tidal forces of the planets on the sun. Jupiter, Venus, Earth and Mercury are called the "tidal planets" because they are the most significant. According to Wood, the especially good alignments of J-V-E with the sun which occur about every 11 years are the cause of the sunspot cycle. He has shown that the sunspot cycle is synchronous with the alignments, and J. Schove's data for 1500 year of sunspot maxima supports the 11.07 year J-V-E period average."<ref name=Tomes/> "Both the 11.86 year Jupiter tropical period (time between perihelion's or closest approaches to the sun and the 9.93 year J-S alignment periods are found in sunspot spectral analysis. Unfortunately direct calculations of the tidal forces of all planets does not support the occurrence of the dominant 11.07 year cycle. Instead, the 11.86 year period of Jupiter's perihelion dominates the results. This has caused problems for several researchers in this field."<ref name=Tomes>{{ cite journal |author=Ray Tomes |title=Towards a Unified Theory of Cycles |publisher=Cycles Research Institute |location= |month=February |year=1990 |editor= |volume= |issue= |pages=21 |url=http://cyclesresearchinstitute.org/cycles-general/tomes_unified_cycles.pdf |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2013-07-07 }}</ref> "[B]y assuming a harmonic variation having a period of 11.13 years ... the phases of such a variation [in polar diameter minus equatorial diameter of the Sun] coincide to within one-fifth of a year with the phases of the sun-spot fluctuations; that, at times corresponding to minimum of sun-spottedness, the polar diameter is relatively larger; that, at times of maximum sun-spottedness, the equatorial diameter is relatively larger. The amplitude of the variation is extremely small, but its reality would seem to be established. [This] at least renders the existence of such periodic fluctuations in the shape of the sun more probable than their non-existence."<ref name=Poor>{{ cite journal |author=Charles Lane Poor |title=An investigation of the figure of the Sun and of possible variations in its size and shape [Reprint of: Annals N.Y. Acad Sci., Vol XVIII, pp.385 - 424] |journal=Contributions from the Rutherford Observatory of Columbia University New York |month=August |year=1908 |volume=26 |issue=08 |pages=385-424 |url= |arxiv= |bibcode=1908CoRut..26..385P |doi= |pmid= |accessdate=2013-05-16 }}</ref> "Solar oblateness, the difference between the equatorial and polar diameters, reflects certain fundamental properties of the Sun. ... the oblateness reflects properties of the Sun's interior, ... [There is] a time varying, excess equatorial brightness [producing] a difference between the equatorial and polar limb darkening functions ... at times when the excess brightness is reduced, the intrinsic visual oblateness can be obtained from the observations without detailed knowledge of the excess brightness. A period of reduced excess brightness occurred in 1973 September."<ref name=Hill>{{ cite journal |author=H. A. Hill |author2=R. T. Stebbins |title=The intrinsic visual oblateness of the sun |journal=The Astrophysical Journal |month=September 1, |year=1975 |volume=200 |issue=09 |pages=471-5 |url= |arxiv= |bibcode=1975ApJ...200..471H |doi=10.1086/153813 |pmid= |accessdate=2013-05-16 }}</ref> The period of reduced excess equatorial brightness occurred between solar cycle maximum around 1970 and minimum around 1975. Considering excess equatorial brightness and seeking to perform measurements at opportunities of reduced excess equatorial brightness has the effect of reducing solar oblateness from some 86.6 ± 6.6 milli-arcsec to 18.4 ± 12.5 milli-arcsec.<ref name=Hill/> The Babcock Model describes a mechanism which can explain magnetic and sunspot patterns observed on the Sun: # The start of the 22-year cycle begins with a well-established dipole field component aligned along the solar rotational axis. The field lines tend to be held by the highly conductive solar plasma of the solar surface. # The solar surface plasma rotation rate is different at different latitudes, and the rotation rate is 20 percent faster at the equator than at the poles (one rotation every 27 days). Consequently, the magnetic field lines are wrapped by 20 percent every 27 days. # After many rotations, the field lines become highly twisted and bundled, increasing their intensity, and the resulting buoyancy lifts the bundle to the solar surface, forming a bipolar field that appears as two spots, being kinks in the field lines. # The sunspots result from the strong local magnetic fields in the solar surface that exclude the light-emitting solar plasma and appear as darkened spots on the solar surface. # The leading spot of the bipolar field has the same polarity as the solar hemisphere, and the trailing spot is of opposite polarity. The leading spot of the bipolar field tends to migrate towards the equator, while the trailing spot of opposite polarity migrates towards the solar pole of the respective hemisphere with a resultant reduction of the solar dipole moment. This process of sunspot formation and migration continues until the solar dipole field reverses (after about 11 years). # The solar dipole field, through similar processes, reverses again at the end of the 22-year cycle. # The magnetic field of the spot at the equator sometimes weakens, allowing an influx of [[Coronal cloud|coronal plasma]] that increases the internal pressure and forms a magnetic bubble which may burst and produce an ejection of coronal mass, leaving a coronal hole with open field lines. Such a coronal mass ejections are a source of the high-speed solar wind. # The fluctuations in the bundled fields convert magnetic field energy into plasma heating, producing emission of electromagnetic radiation as intense ultraviolet (UV) and X-rays. {{clear}} ==Stellar winds== [[Image:SpaceEnvironmentOverview From 19830101.jpg|thumb|right|200px|This image shows an overview of the space weather conditions over several solar cycles including the relationship between sunspot numbers and cosmic rays. Credit: [[commons:User:Daniel Wilkinson|Daniel Wilkinson]].]] "The '''solar wind''' is a stream of [[w:charged particle|charged particle]]s ejected from the [[w:stellar atmosphere|upper atmosphere]] of the [[Sun (star)|Sun]]. It mostly consists of electrons and protons with energies usually between 1.5 and 10 [[w:electronvolt|keV]]. Δ''T''_''A'' may have values from "7-19 min for a small sample of well-connected ... cosmic-ray flares."<ref name="Cliver"/> The transit time anomaly may be explained by a rise time associated with the ground-level events (GLEs). "The average GLE rise time ... for well-connected ... events ... defined to be the time from event onset to maximum as measured by the neutron monitor station showing the largest increase and whose asymptotic cone of acceptance ... includes the nominal direction of the Archimedean spiral path, is 21.3 min."<ref name="Cliver"/> The solar wind originates through the polar coronal holes. "The solar wind is a plasma, composed primarily of electrons and lone protons, and the variations in the index of refraction are caused by variations in the density of the plasma.<ref>Jokipii (1973), pp. 11–12.</ref> Different indices of refraction result in phase changes between waves traveling through different locations, which results in interference. As the waves interfere, both the frequency of the wave and its angular size are broadened, and the intensity varies.<ref>Alurkar (1997), p. 11.</ref>"<ref name=McBride>{{ cite web |author=[[w:User:James McBride|James McBride]] |title=Interplanetary scintillation |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=October 1, 2013 |url=https://en.wikipedia.org/wiki/Interplanetary_scintillation |accessdate=2014-01-23 }}</ref> ==Van Allen radiation belts== The '''Van Allen radiation belt''' is split into two distinct belts, with energetic electrons forming the outer belt and a combination of protons and electrons forming the inner belts. In addition, the radiation belts contain lesser amounts of other nuclei, such as [[w:alpha particle|alpha particle]]s. The trapped particle population of the outer belt is varied, containing electrons and various ions. Most of the ions are in the form of energetic protons, but a certain percentage are [[w:alpha particles|alpha particles]] and O⁺ oxygen ions, similar to those in the [[w:ionosphere|ionosphere]] but much more energetic. While protons form one radiation belt, trapped electrons present two distinct structures, the inner and outer belt. The inner electron Van Allen Belt extends typically from an altitude of 1.2 to 3 Earth radii (L values of 1 to 3).<ref name=Ganushkina>{{ cite journal | author=Ganushkina N.Y. |author2=I. Dandouras |author3=Y. Y. Shprits |author4=J. Cao | title=Locations of boundaries of outer and inner radiation belts as observed by Cluster and Double Star | journal=Journal of Geophysical Research | volume=116 |issue=A09234 |doi=10.1029/2010JA016376 | year=2011 | pages=1–18 |url=http://onlinelibrary.wiley.com/doi/10.1029/2010JA016376/abstract }}</ref> In certain cases when solar activity is stronger or in geographical areas such as the [[w:South Atlantic Anomaly|South Atlantic Anomaly]] (SAA), the inner boundary may go down to roughly 200 kilometers<ref>{{ cite book |title=ECSS Space engineering |date=15 November 2008 |url=https://www.scribd.com/document/122967505/ECSS-space-engineering }}</ref> above the Earth's surface. The inner belt contains high concentrations of electrons in the range of hundreds of keV and energetic protons with energies exceeding 100 MeV, trapped by the strong (relative to the outer belts) magnetic fields in the region.<ref name=Gusev>{{ cite journal | author=Gusev A.A. |author2=G.I. Pugacheva |author3=U.B. Jayanthi |author4=N. Schuch | title=Modeling of Low-altitude Quasi-trapped Proton Fluxes at the Equatorial Inner Magnetosphere | journal=Brazilian Journal of Physics | vol. 33 | no. 4 | year=2003 | pages=775–781 |url=http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-97332003000400029 }}</ref> It is believed that proton energies exceeding 50 MeV in the lower belts at lower altitudes are the result of the [[w:beta decay|beta decay]] of [[w:neutrons|neutrons]] created by cosmic ray collisions with nuclei of the upper atmosphere. The source of lower energy protons is believed to be proton diffusion due to changes in the magnetic field during geomagnetic storms.<ref name=Tascione>{{ cite book | first=Thomas F. | last=Tascione | title=Introduction to the Space Environment, 2nd. Ed. | publisher=Kreiger Publishing CO.| location=Malabar, Florida USA | year=1994 |url=http://astrobooks.com/introductiontothespaceenvironmentsecondeditionsoftbackthomasftascione-1994.aspx | isbn=0-89464-044-5}}</ref> Due to the slight offset of the belts from Earth's geometric center, the inner Van Allen belt makes its closest approach to the surface at the South Atlantic Anomaly.<ref name="Goddard">NASA Goddard Spaceflight Center, |url=http://image.gsfc.nasa.gov/poetry/tour/AAvan.html |title=The Van Allen Belts] (Accessed May 25, 2011)</ref><ref name=Underwood>{{ cite journal | author=Underwood, C. |author2=Brock, D. |author3=Williams, P. |author4=Kim, S. |author5=Dilão, R. |author6=Ribeiro Santos, P. |author7=Brito, M. |author8=Dyer, C. |author9=Sims, A. | title=Radiation Environment Measurements with the Cosmic Ray Experiments On-Board the KITSAT-1 and PoSAT-1 Micro-Satellites | journal=IEEE Transactions on Nuclear Sciences | volume=41 | year=1994 | pages=2353–2360 |url=http://ieeexplore.ieee.org/document/340587/ }}</ref> The proton belts contain [[w:protons|protons]] with kinetic energies ranging from about 100 keV (which can penetrate 0.6&nbsp;microns of lead) to over 400 MeV (which can penetrate 143&nbsp;mm of lead).<ref name=Hess>{{cite book |author=Wilmot N. Hess |title=The Radiation Belt and Magnetosphere |publisher=Blaisdell Pub. Co. |date=1968 |url=http://adsabs.harvard.edu/abs/1968rbm..book.....H }}</ref> The [[w:Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics|PAMELA]] experiment detected orders of magnitude higher levels of [[w:antiproton|antiproton]]s than are expected from normal [[w:particle decay|particle decay]]s while passing through the SAA. This suggests the van Allen belts confine a significant flux of antiprotons produced by the interaction of the Earth's upper atmosphere with [[w:cosmic rays|cosmic rays]].<ref name=Adriani>{{ cite journal | doi = 10.1088/2041-8205/737/2/L29 | title = The Discovery of Geomagnetically Trapped Cosmic-Ray Antiprotons | year = 2011 | last1 = Adriani | first1 = O. | last2 = Barbarino | first2 = G. C. | last3 = Bazilevskaya | first3 = G. A. | last4 = Bellotti | first4 = R. | last5 = Boezio | first5 = M. | last6 = Bogomolov | first6 = E. A. | last7 = Bongi | first7 = M. | last8 = Bonvicini | first8 = V. | last9 = Borisov | first9 = S. | journal = The Astrophysical Journal Letters | volume = 737 | issue = 2 | pages = L29 | bibcode = 2011ApJ...737L..29A | arxiv=1107.4882v1 }}</ref> The energy of the antiprotons has been measured in the range from 60 - 750 [[w:Electron volt|MeV]]. When cosmic-ray protons enter the Earth’s atmosphere they collide with molecules, mainly oxygen and nitrogen, to produce a cascade of billions of lighter particles, a so-called air shower. An air shower is an extensive (many kilometres wide) cascade of ionized particles and electromagnetic radiation produced in the atmosphere when a primary cosmic-ray proton (i.e. one of extraterrestrial origin) enters the atmosphere. During [[w:solar proton event|solar proton event]]s, ionization can reach unusually high levels in the D-region over high and polar latitudes. Such very rare events are known as Polar Cap Absorption (or PCA) events, because the increased ionization significantly enhances the absorption of radio signals passing through the region. In fact, absorption levels can increase by many tens of dB during intense events, which is enough to absorb most (if not all) transpolar HF radio signal transmissions. Such events typically last less than 24 to 48 hours. Associated with solar flares is a release of high-energy protons. These particles can hit the Earth within 15 minutes to 2 hours of the solar flare. The protons spiral around and down the magnetic field lines of the Earth and penetrate into the atmosphere near the magnetic poles increasing the ionization of the D and E layers. PCA's typically last anywhere from about an hour to several days, with an average of around 24 to 36 hours. ==Cosmic rays== {{main|Radiation/Cosmic rays}} "A persistent problem of solar cosmic-ray research has been the lack of observations bearing on the timing and conditions in which protons that escape to the interplanetary medium are first accelerated in the corona."<ref name="Cliver">{{cite journal |author=E. W. Cliver |author2=S. W. Kahler |author3=M. A. Shea |author4=D. F. Smart |title=Injection onsets of ~2 GeV protons, ~1 MeV electrons, and ~100 keV electrons in solar cosmic ray flares |journal=The Astrophysical Journal |month=September 1 |year=1982 |volume=260 |issue=9 |pages=362-70 |url= |arxiv= |bibcode=1982ApJ...260..362C |doi= |pmid= |accessdate=2012-08-21 }}</ref> "For solar cosmic-rays, the apparent lack of proton acceleration in the corona seems justified, in contrast to the electrons, proton bremsstrahlung and gyrosynchrotron emission are negligible. This suggests a transit time anomaly, Δ''T''_''A'', defined as follows: : Δ''T''_''A'' = Δ''T''_onset - 11 min, where Δ''T''_onset is the deduced Sun-Earth transit time for the first arriving relativistic protons and 11 min is the nominal transit time for a ~2 GeV proton traversing a 1.3 AU Archimedes spiral path."<ref name="Cliver">{{cite journal |author=E. W. Cliver |author2=S. W. Kahler |author3=M. A. Shea |author4=D. F. Smart |title=Injection onsets of ~2 GeV protons, ~1 MeV electrons, and ~100 keV electrons in solar cosmic ray flares |journal=The Astrophysical Journal |month=September 1 |year=1982 |volume=260 |issue=9 |pages=362-70 |url= |arxiv= |bibcode=1982ApJ...260..362C |doi= |pmid= |accessdate=2012-08-21 }}</ref> ==Protons== {{main|Radiation astronomy/Protons|Proton astronomy}} [[Image:GOES protons.jpg|thumb|right|250px|This graph displays the flux of high energy protons measured by GOES 11 over four days from November 2, 2004, to November 4, 2003. Credit: NOAA.]] The Sun and the solar wind, at least that portion that originates through the polar coronal holes apparently from the photosphere, may be major sources of protons within the solar system. At right is a temporal distribution of solar proton flux in units of particles cm^-2 s^-1 sr^-1 as measured by GOES 11 over the four days from November 2, 2003, to November 4, 2003, in three windows of energy: ≥ 100 MeV (green), ≥ 50 MeV (blue), and ≥ 10 MeV (red). The percentage originating from the surface of the Sun either directly or through the contribution to the solar wind is not indicated. {{clear}} ==Electrons== {{main|Radiation astronomy/Electrons}} "The density of the coronal cloud deduced in this case is about 2 x 10¹¹ electrons per cubic centimeter."<ref name=Zinn1965>{{ cite book |author=H. Zinn |title=Solar Flares and Concurrent Phenomena in the Solar Atmosphere, In: ''Proceedings of the Plasma Space Science Symposium'' |publisher=Springer |location=Netherlands |year=1965 |editor=C. C. Chang |editor2=S. S. Huang |volume=3 |issue= |pages=38-51 |url=http://link.springer.com/chapter/10.1007/978-94-011-7542-5_5 |arxiv= |bibcode= |doi=10.1007/978-94-011-7542-5_5 |pmid= |isbn=978-94-011-7544-9 |accessdate=2013-07-07 }}</ref> ==Positrons== {{main|Radiation astronomy/Positrons}} [[Image:Rhessi0269 web.jpg|thumb|right|250px|RHESSI observes high-energy phenomena from a solar flare. Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio.]] The solar flare at Active Region 10039 on July 23, 2002, exhibits many exceptional high-energy phenomena including the 2.223 MeV neutron capture line and the 511 keV electron-positron (antimatter) annihilation line. In the image at right, the RHESSI low-energy channels (12-25 keV) are represented in red and appear predominantly in coronal loops. The high-energy flux appears as blue at the footpoints of the coronal loops. Violet is used to indicate the location and relative intensity of the 2.2 MeV emission. During solar flares “[s]everal radioactive nuclei that emit positrons are also produced; [which] slow down and annihilate in flight with the emission of two 511 keV photons or form positronium with the emission of either a three gamma continuum (each photon < 511 keV) or two 511 keV photons."<ref name=Share>{{ cite book |author=Gerald H. Share |author2=Ronald J. Murphy |title=Solar Gamma-Ray Line Spectroscopy – Physics of a Flaring Star, In: ''Stars as Suns: Activity, Evolution and Planets'' |publisher=Astronomical Society of the Pacific |location=San Francisco, CA |date=January 2004 |editor=Andrea K. Dupree, A. O. Benz |pages=133-44 |url=http://heseweb.nrl.navy.mil/gamma/solar/papers/share_iau_04.pdf |arxiv= |bibcode=2004IAUS..219..133S |doi= |pmid= |isbn=158381163X |accessdate=2012-03-15 }}</ref> The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) made the first high-resolution observation of the solar positron-electron annihilation line during the July 23, 2003 solar flare.<ref name=Share/> The observations are somewhat consistent with electron-positron annihilation in a quiet solar atmosphere via positronium as well as during flares.<ref name=Share/> Line-broadening is due to "the velocity of the positronium."<ref name=Share/> "The width of the annihilation line is also consistent ... with thermal broadening (Gaussian width of 8.1 ± 1.1 keV) in a plasma at 4-7 x 10⁵ K. ... The ''RHESSI'' and all but two of the ''SMM'' measurements are consistent with densities ≤ 10¹² H cm^-3 [but] <10% of the p and α interactions producing positrons occur at these low densities. ... positrons produced by ³He interactions form higher in the solar atmosphere ... all observations are consistent with densities > 10¹² H cm^-3. But such densities require formation of a substantial mass of atmosphere at transition region temperatures."<ref name=Share/> {{clear}} ==Neutrinos== {{main|Radiation astronomy/Neutrinos|Neutrino astronomy}} [[Image:Neusun1 superk1.jpg|thumb|right|250px|This "neutrino image" of the Sun is produced by using the Super-Kamiokande to detect the neutrinos from nuclear fusion coming from the Sun. Credit: R. Svoboda and K. Gordan (LSU).]] [[Image:Bahcall Figure 2.jpg|thumb|right|250px|This figure shows a detected 94 % correlation between scaled sunspot numbers and neutrino detections. Credit: John N. Bahcall.]] Neutrinos are hard to detect. The Super-Kamiokande, or "Super-K" is a large-scale experiment constructed in an unused mine in Japan to detect and study neutrinos. The image at right required 500 days worth of data to produce the "neutrino image" of the Sun. The image is centered on the Sun's calculated position. It covers a 90° x 90° octant of the sky (in right ascension and declination). The higher the brightness of the color, the larger is the neutrino flux. The surface of the Sun is not a known source of neutrinos. Those detected may be from nucleosynthesis within the coronal cloud in the near vicinity of the Sun or perhaps from nucleosynthesis occurring interior to the Sun. "[N]eutrino flux increases noted in Homestake results [coincide] with major solar flares [14]."<ref name=Dubin>{{ cite journal |author=Maurice Dubin |author2=Robert K. Soberman |title=Resolution of the Solar Neutrino Anomaly |journal=arXiv |date=April 1996 |volume= |issue= |pages=1-8 |url=http://arxiv.org/abs/astro-ph/9604074 |arxiv=astro-ph/9604074 |bibcode=1996astro.ph..4074D |doi= |pmid= |pdf=http://arxiv.org/pdf/astro-ph/9604074.pdf |accessdate=2012-11-11 }}</ref> This result together with those in the next two paragraphs establishes that neutrinos are being produced by processes above the photosphere and probably within 2-4 solar radii as most solar flares give off energy close to and into the chromosphere. "The correlation between a great solar flare and Homestake neutrino enhancement was tested in 1991. Six major flares occurred from May 25 to June 15 including the great June 4 flare associated with a coronal mass ejection and production of the strongest interplanetary shock wave ever recorded (later detected from spacecraft at 34, 35, 48, and 53 AU) [15]. It also caused the largest and most persistent (several months) signal ever detected by terrestrial cosmic ray neutron monitors in 30 years of operation [16]. The Homestake exposure (June 1–7) measured a mean ³⁷Ar production rate of 3.2 ± 1.5 atoms/day (≈19 ³⁷Ar atoms produced in 6 days) [13]; about 5 times the rate of ≈ 0.65 day ⁻¹ for the preceding and following runs, > 6 times the long term mean of ≈ 0.5 day⁻¹ and > 2 1/2 times the highest rates recorded in ∼ 25 operating years."<ref name=Dubin/> The highest flux of solar neutrinos come directly from the proton-proton interaction, and have a low energy, up to 400 keV. There are also several other significant production mechanisms, with energies up to 18 MeV.<ref name=Bellerive>A. Bellerive, [http://arxiv.org/abs/hep-ex/0312045 Review of solar neutrino experiments]. Int.J.Mod.Phys. A19 (2004) 1167-1179</ref> The parts of the Sun above the photosphere are referred to collectively as the ''solar atmosphere''.<ref name=Abhyankar1977>{{ cite journal |author=K.D. Abhyankar |title=A Survey of the Solar Atmospheric Models 1977 |journal=Bull. Astr. Soc. India |volume=5 |bibcode=1977BASI....5...40A |pages=40–44 |url=http://prints.iiap.res.in/handle/2248/510 }}</ref> "Neutrinos can be produced by energetic protons accelerated in solar magnetic fields. Such protons produce pions, and therefore muons, hence also neutrinos as a decay product, in the solar atmosphere."<ref name=Bahcall1987>{{ cite journal |author=J. N. Bahcall |author2=G. B. Field |author3=W. H. Press |title=Is solar neutrino capture rate correlated with sunspot number? |journal=The Astrophysical Journal |date=September 1, 1987 |volume=320 |issue=9 |pages=L69-73 |url=http://articles.adsabs.harvard.edu//full/1987ApJ...320L..69B/L000069.000.html |arxiv= |bibcode=1987ApJ...320L..69B |doi=10.1086/184978 |pmid= |accessdate=2013-07-07 }}</ref> "Energetic protons in the solar corona could explain Figure 2 [at right] only if (1) they tap a substantial fraction of the entire energy generated in the corona, (2) the energy generated in the corona is at least 3 times what has been deduced from the observations, (3) the vast majority of energetic protons do not escape the Sun, (4) the proton energy spectrum is unusually hard (''p''₀ = 300 MeV c^-1, and (5) the sign of the variation is opposite to what one would predict. As the likelihood of all of these conditions being fulfilled seems extremely small, we do not believe that neutrinos produced by energetic protons in the solar atmosphere contribute significantly to the neutrino capture in the ³⁷Cl experiment."<ref name=Bahcall1987/> "The total number of neutrinos of all types agrees with the number predicted by the computer model of the Sun. Electron neutrinos constitute about a third of the total number of neutrinos. [...] The missing neutrinos were actually present, but in the form of the more difficult to detect muon and tau neutrinos."<ref name=Bahcall2004>{{ cite book |author=John N. Bahcall |title=Solving the Mystery of the Missing Neutrinos |publisher=Nobel Media AB |location= |date=April 28, 2004 |url=http://www.nobelprize.org/nobel_prizes/themes/physics/bahcall/ |accessdate=2014-03-08 }}</ref> The reactions that produce the higher energy neutrinos: ν_µ and ν_τ are. For antiproton-proton annihilation at rest, a meson result is, for example, :<math>p^+ + \bar{p}^- \rightarrow \pi^+ + \pi^-,</math><ref name=Klempt>{{ cite journal |author=Eberhard Klempt |author2=Chris Batty |author3=Jean-Marc Richard |title=The antinucleon-nucleon interaction at low energy: annihilation dynamics |journal=Physics Reports |date=July 2005 |volume=413 |issue=4-5 |pages=197-317 |url=http://adsabs.harvard.edu/abs/2005PhR...413..197K |arxiv=hep-ex/0501020 |bibcode=2005PhR...413..197K |doi=10.1016/j.physrep.2005.03.002 |pmid= |accessdate=2014-03-09 }}</ref> :<math>{\pi}^+ \rightarrow {\mu}^+ + {\nu}_{\mu} \rightarrow e^+ + {\nu}_e + {\bar{\nu}}_{\mu} + {\nu}_{\mu},</math><ref name=Waxman>{{ cite journal |author=Eli Waxman |author2=John Bahcall |title=High energy neutrinos from astrophysical sources: An upper bound |journal=Physical Review D |date=December 14, 1998 |volume=59 |issue=2 |pages=e023002 |url=http://prd.aps.org/abstract/PRD/v59/i2/e023002 |arxiv=hep--ph/9807282 |bibcode= |doi=10.1103/PhysRevD.59.023002 |pmid= |accessdate=2014-03-09 }}</ref> and :<math>D_S \rightarrow \tau + \bar{\nu}_{\tau} \rightarrow \nu_{\tau} + \bar{\nu}_{\tau}.</math><ref name=Kodama>{{ cite journal |author=K. Kodama |author2=N. Ushida1 |author3=C. Andreopoulos |author4=N. Saoulidou |author5=G. Tzanakos |author6=P. Yager |author7=B. Baller |author8=D. Boehnlein |author9=W. Freeman |author10=B. Lundberg |author11=J. Morfin |author12=R. Rameika |author13=J.C. Yun |author14=J.S. Song |author15=C.S. Yoon |author16=S.H.Chung |author17=P. Berghaus |author18=M. Kubanstev |author19=N.W. Reay |author20=R. Sidwell |author21=N. Stanton |author22=S. Yoshida |author23=S. Aoki |author24=T. Hara |author25=J.T. Rhee |author26=D. Ciampa |author27=C. Erickson |author28=M. Graham |author29=K. Heller |author30=R. Rusack |author31=R. Schwienhorst |author32=J. Sielaff |author33=J. Trammell |author34=J. Wilcox |author35=K. Hoshino |author36=H. Jiko |author37=M. Miyanishi |author38=M. Komatsu |author39=M. Nakamura |author40=T. Nakano |author41=K. Niwa |author42=N. Nonaka |author43=K. Okada |author44=O. Sato |author45=T. Akdogan |author46=V. Paolone |author47=C. Rosenfeld |author48=A. Kulik |author49=T. Kafka |author50=W. Oliver |author51=T. Patzak |author52=J. Schneps |title=Observation of tau neutrino interactions |journal=Physics Letters B |date=April 12, 2001 |volume=504 |issue=3 |pages=218-24 |url=http://www.sciencedirect.com/science/article/pii/S0370269301003070 |arxiv= |bibcode= |doi= |pmid= |accessdate=2014-03-10 }}</ref> "All other sources of ν_τ are estimated to have contributed an additional 15%."<ref name=Kodama/> :<math>\tau \rightarrow e + \nu_{\tau} + \nu_e,</math><ref name=Kodama/> for two neutrinos.<ref name=Kodama/> :<math>\tau \rightarrow h + \nu_{\tau} + X,</math><ref name=Kodama/> where <math>h</math> is a hadron, for two neutrinos.<ref name=Kodama/> {{clear}} ==Gamma rays== {{main|Radiation astronomy/Gamma rays|Gamma-ray astronomy}} [[Image:Gamma sun1.jpg|thumb|right|250px|The Sun is seen in gamma rays by COMPTEL during a June 15, 1991, solar flare. Credit: COMPTEL team, University of New Hampshire.]] The surface of the Sun has yet to be detected as a gamma ray source, reflector, or in fluorescence. RHESSI was the first satellite to image solar gamma rays from a solar flare.<ref>[http://adsabs.harvard.edu/abs/2003ApJ...595L..77H] First Gamma-Ray Images of a Solar Flare (Hurford et al. 2003)</ref> {{clear}} ==X-rays== {{main|Radiation astronomy/X-rays|X-ray astronomy}} [[Image:X-ray image of the Pleiades.gif|thumb|right|250px|The image shows the Pleiades in X-rays, taken by ROSAT, where the brightest optical stars are inside the green squares. Credit: [[w:User:Worldtraveller|Worldtraveller]].]] "The Pleiades star cluster is one of the jewels of the northern sky. To the unaided eye it appears as an alluring group of stars in the constellation Taurus, while telescopic views reveal cluster stars surrounded by delicate blue wisps of dust-reflected starlight. To the X-ray telescopes on board the orbiting ROSAT observatory, the cluster also presents an impressive, but slightly altered, appearance. This false color image [at right] was produced from ROSAT observations by translating different X-ray energy bands to visual colors - the lowest energies are shown in red, medium in green, and highest energies in blue. (The green boxes mark the position of the seven brightest visual stars.) The Pleiades stars seen in X-rays have extremely hot, tenuous outer atmospheres called coronas and the range of colors corresponds to different coronal temperatures."<ref name=Nemiroff1999>{{ cite book |author=Robert Nemiroff |author2=Jerry Bonnell |title=X-Ray Pleiades |publisher=NASA/GSFC |location=Greenbelt, Maryland USA |date=August 28, 1999 |url=http://apod.nasa.gov/apod/ap990828.html |accessdate=2013-07-07 }}</ref> {{clear}} ==Ultraviolets== {{main|Radiation astronomy/Ultraviolets|Ultraviolet astronomy}} [[Image:August 2010 CME SDO.jpg|thumb|right|200px|A coronal mass ejection is shown in the ultraviolet. Credit: NASA/SDO.]] [[Image:STEREO B EUVI 171.jpg|thumb|left|250px|The chromosphere of the Sun shows in ultraviolets. Credit: STEREO (NASA).]] "One of the fastest CMEs in years was captured by the STEREO COR1 telescopes on August 1, 2010. ... This CME is seen to be heading towards Earth at speeds well over 1000 kilometers per second."<ref name=Zell/> "On August 1st, almost the entire Earth-facing side of the sun erupted in a tumult of activity. There was a C3-class solar flare, a solar tsunami, multiple filaments of magnetism lifting off the stellar surface, large-scale shaking of the solar corona, radio bursts, a coronal mass ejection and more. This extreme ultraviolet snapshot [at right] from the Solar Dynamics Observatory (SDO) shows the sun's northern hemisphere in mid-eruption. Different colors in the image represent different gas temperatures ranging from ~1 to 2 million degrees K."<ref name=Zell>{{ cite book |author=Holly Zell |title=Spacecraft Observes Coronal Mass Ejection |publisher=NASA |location=Washington, DC USA |date=August 4, 2010 |url=http://www.nasa.gov/topics/solarsystem/sunearthsystem/main/News080210-cme.html |accessdate=2013-07-07 }}</ref> {{clear}} ==Non-polar solar coronal holes== [[Image:Coronalhole.jpg|right|thumb|250px|Solar Disk with Coronal Hole - May 25, 2007 - by NASA STEREO (Solar TErrestrial RElations Observatory). Credit: NASA STEREO (Solar TErrestrial RElations Observatory).{{tlx|free media}}]] [[Image:417176main SDO Guide CMR Page 26 Image 0002.jpg|right|thumb|250px|A coronal hole is shown in extreme UV light. Credit: NASA.{{tlx|free media}}]] [[Image:Cor hole May-thumb-570x570-123594.jpg|thumb|right|250px|Coronal holes are areas on the Sun's corona that are darker, lower-density, and (relatively) colder than the rest of the plasma above the surface of our nearest star. Credit: NASA.{{tlx|fairuse}}]] [[Image:Two Coronal Holes on the Sun Viewed by SDO (16658479920).jpg|right|thumb|250px|NASA’s Solar Dynamics Observatory, or SDO, captured this solar image on March 16, 2015, which clearly shows two dark patches, known as coronal holes. Credit: NASA/Goddard/SDO.{{tlx|free media}}]] [[Image:Coronal Hole Front and Center.jpg|right|thumb|300px|The high-speed solar wind originating from this coronal hole, imaged hereon Oct. 10, 2015, by NASA's Solar Dynamics Observatory, created a geomagnetic storm near Earth that resulted in several nights of auroras. Credit: NASA/SDO.{{tlx|free media}}]] [[Image:PIA22197-SunFormsQuestionMark-20171222.jpg|right|thumb|250px|NASA's Solar Dynamics Observatory observed an elongated coronal hole (the darker area near the center) seeming to shape itself into a single, recognizable question mark over the period of one day (Dec. 21-22, 2017). Credit: .{{tlx|free media}}]] "The striking absence of green emission above both polar regions at activity minimum led Waldmeier (1957) to use the German term 'Koronalöcher', ie, coronal holes."<ref name=Schwenn>{{ cite journal |author=R. Schwenn |author2=B. Inhester |author3=S. P. Plunkett |author4=A. Epple |author5=B. Podlipnik |author6=D. K. Bedford |author7=C. J. Eyles |author8=G. M. Simnett |author9=S. J. Tappin |author10=M. V. Bout |author11=et al. |title=First View of the Extended Green-Line Emission Corona At Solar Activity Minimum Using the Lasco-C1 Coronagraph on Soho |journal=Solar Physics |month=October |year=1997 |volume=175 |issue=2 |pages=667-84 |url=http://www.springerlink.com/index/R10HN0R60R081237.pdf |arxiv= |bibcode= |doi=10.1023/A:1004948913883 |pmid= |accessdate=2012-02-17 }}</ref> "Here we restrict ourselves to a qualitative study of large scale structures of the green emission line corona."<ref name=Schwenn/> The image descriptions that follow emphasize various non-polar holes. For the coronal hole from 25 May 2007: the image of the solar coronal cloud at top right shows both of the polar coronal holes and one apparently isolated, non-polar coronal hole. Third image down on the right: "Coronal holes are areas on the sun's corona that are darker, lower-density, and (relatively) colder than the rest of the plasma on the surface of our nearest star. They're the source of the kind of solar wind gusts that carry solar particles out to our magnetosphere and beyond, causing auroras (and, less awesomely, geomagnetic storms) here on Earth."<ref name=Garber>{{ cite book |author=Megan Garber |title=No Big Deal, Just a Giant Hole in the Sun |publisher=The Atlantic |location= |date=5 June 2013 |url=http://www.theatlantic.com/technology/archive/2013/06/no-big-deal-just-a-giant-hole-in-the-sun/276564/ |accessdate=2015-05-18 }}</ref> "When coronal holes are captured in extreme ultraviolet light images, they reveal themselves as dark spots that appear, to human eyes, to be plasma voids."<ref name=Garber/> "Well, last week -- between May 28 and 31 -- one of those coronal holes rotated toward Earth. It was a big one: "one of the largest," NASA says, "we have seen in a year or more." And the Solar Dynamics Observatory's Atmospheric Imaging Assembly, fortunately, got a shot of the thing. Above, via a combination of three wavelengths of UV light, is an image of the hole. It's pretty gorgeous, as holes go."<ref name=Garber/> "And while coronal holes are more likely to affect Earth after they've rotated more than halfway around the visible hemisphere of the sun -- which was the case with this guy -- the most this one would have done, astronomers say, was to generate some aurora."<ref name=Garber/> The image third down on the right shows one of the largest non-polar coronal holes ever observed in May, apparently in 2013. For the fourth image down on the right: "NASA’s Solar Dynamics Observatory, or SDO, captured this solar image on March 16, 2015, which clearly shows two dark patches, known as coronal holes. The larger coronal hole of the two, near the southern pole, covers an estimated 6- to 8-percent of the total solar surface. While that may not sound significant, it is one of the largest polar holes scientists have observed in decades. The smaller coronal hole, towards the opposite pole, is long and narrow. It covers about 3.8 billion square miles on the sun - only about 0.16-percent of the solar surface."<ref name=Goddard2015>{{ cite book |author=NASA/Goddard/SDO |title=Two Coronal Holes on the Sun Viewed by SDO |publisher=Goddard Space Flight Center |location=Greenbelt, Maryland USA |date=17 March 2015 |editor= |pages=1 |url=https://www.flickr.com/people/24662369@N07 |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2018-02-07 }}</ref> Per the fifth image down on the right: "The dark area across the top of the sun in this image is a coronal hole, a region on the sun where the magnetic field is open to inter planetary space, sending coronal material speeding out in what is called a high-speed solar wind stream. The high-speed solar wind originating from this coronal hole, imaged hereon Oct. 10, 2015, by NASA's Solar Dynamics Observatory, created a geomagnetic storm near Earth that resulted in several nights of auroras. This image was taken in wavelengths of 193 Angstroms, which is invisible to our eyes and is typically colorized in bronze."<ref name=NASA>{{ cite book |author=NASA/SDO |title=Coronal Hole Front and Center |publisher=GSFC |location=Greenbelt, Maryland USA |date=15 October 2015 |editor= |pages=1 |url=https://www.nasa.gov/image-feature/goddard/coronal-hole-front-and-center |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2018-02-07 }}</ref> Relative to the sixth image down on the right: "Oddly enough, an elongated coronal hole (the darker area near the center) seems to shape itself into a single, recognizable question mark over the period of one day (Dec. 21-22, 2017). Coronal holes are areas of open magnetic field that appear darker in extreme ultraviolet light, as is seen here. These holes are the source of streaming plasma that we call solar wind."<ref name=Dynamics>{{ cite web |author=NASA/GSFC/Solar Dynamics Observatory |title=PIA22197: The Sun Forms a Question |publisher=GSFC |location=Greenbelt, Maryland USA |date=29 December 2017 |editor= |pages=1 |url=https://photojournal.jpl.nasa.gov/jpeg/PIA22197.jpg |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2018-02-07 }}</ref> While the hole is connected to the polar coronal hole it does extend to mid-latitudes. {{clear}} ==Saturn== "Saturn's corona plays a major role in supplying hydrogen to the circumplanetary volume."<ref name=Smyth>{{ cite web |author=W.H. Smyth, M.R. Combi |title=Extended atmospheres of outer planet satellites and comets. Interim report, 15 June-14 September 1987 |publisher= |location= |date=November 1, 1987 |pages=122 |url=http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=5275119 |accessdate=2013-07-10 }}</ref> "This cloud probably connects to the extended hydrogen corona of Saturn (Broadfoot et al., 1981; Shemansky and Hall, 1992) and to hydrogen-rich icy surfaces in the inner magnetosphere."<ref name=Young>{{ cite journal |author=D. T. Young |author2=J. J. Berthelier |author3=M. Blanc |author4=J. L. Burch |author5=A. J. Coates |author6=R. Goldstein |author7=M. Grande |author8=T. W. Hill |author9=R. E. Johnson |author10=V. Kelha |author11=D. J. Mccomas |author12=E. C. Sittler |author13=K. R. Svenes |author14=K. Szegö |author15=P. Tanskanen |author16=K. Ahola |author17=D. Anderson |author18=S. Bakshi |author19=R. A. Baragiola |author20=B. L. Barraclough |author21=R. K. Black |author22=S. Bolton |author23=T. Booker |author24=R. Bowman |author25=P. Casey |author26=F. J. Crary |author27=D. Delapp |author28=G. Dirks |author29=N. Eaker |author30=H. Funsten |author31=J. D. Furman |author32=J. T. Gosling |author33=H. Hannula |author34=C. Holmlund |author35=H. Huomo |author36=J. M. Illiano |author37=P. Jensen |author38=M. A. Johnson |author39=D. R. Linder |author40=T. Luntama |author41=S. Maurice |author42=K. P. Mccabe |author43=K. Mursula |author44=B. T. Narheim |author45=J. E. Nordholt |author46=A. Preece |author47=J. Rudzki |author48=A. Ruitberg |author49=K. Smith |author50=S. Szalai |author51=M. F. Thomsen |author52=K. Viherkanto |author53=J. Vilppola |author54=T. Vollmer |author55=T. E. Wahl |author56=M. Wüest |author57=T. Ylikorpi |author58=C. Zinsmeyer |title=Cassini plasma spectrometer investigation |journal=Space Science Reviews |month=September |year=2004 |volume=114 |issue=1-4 |pages=1-112 |url=http://link.springer.com/article/10.1007/s11214-004-1406-4 |arxiv= |bibcode= |doi=10.1007/s11214-004-1406-4 |pmid= |accessdate=2013-07-10 }}</ref> ==Brown dwarfs== [[Image:Lp94420 duo m.jpg|thumb|250px|[[w:Chandra X-ray Observatory|Chandra]] image of LP 944-20 before flare and during flare. Credit: .]] Some brown dwarfs emit X-rays. Here are some X-ray milestones from the same article: * 1998: First X-ray-emitting brown dwarf found. Cha Halpha 1, an M8 object in the [[w:Chamaeleon I|Chamaeleon I]] dark cloud, is determined to be an X-ray source, similar to convective late-type stars. * December 15, 1999: First X-ray flare detected from a brown dwarf. A team at the University of California monitoring LP 944-20 (60 Jupiter masses, 16 ly away) via the [[w:Chandra X-ray Observatory|Chandra X-ray Observatory]], catches a 2-hour flare. X-ray flares detected from brown dwarfs since late 1999 suggest changing [[w:magnetic field of celestial bodies|magnetic fields]] similar to those in very low-mass stars. When combined with the rapid rotation that most brown dwarfs exhibit, conditions [may exist] for the development of a strong, tangled [[w:magnetic field|magnetic field]] near the surface. The flare observed by [[w:Chandra X-ray Observatory|Chandra]] from LP 944-20 could have its origin in the turbulent magnetized hot material that may conduct heat to the atmosphere, allowing electric currents to flow and produce an X-ray flare, like a stroke of [[w:lightning|lightning]]. The absence of X-rays from LP 944-20 during the non flaring period is also a significant result. It sets the lowest observational limit on steady X-ray power produced by a brown dwarf star, and shows that coronas cease to exist as the surface temperature of a brown dwarf cools below about 2500°C and becomes electrically neutral. Using NASA's [[w:Chandra X-ray Observatory|Chandra X-ray Observatory]], scientists have detected X-rays from a low-mass brown dwarf in a multiple star system.<ref name=Williams2003>{{ cite book |date=14 April 2003 |title=X-rays from a Brown Dwarf's Corona |url=http://www.williams.edu/Astronomy/jay/chapter18_etu6.html }}</ref> This is the first time that a brown dwarf this close to its parent star(s) (Sun-like stars TWA 5A) has been resolved in X-rays.<ref name=Williams2003/> "Our Chandra data show that the X-rays originate from the brown dwarf's coronal plasma which is some 3 million degrees Celsius", said Yohko Tsuboi of [[w:Chuo University|Chuo University]] in Tokyo.<ref name=Williams2003/> "This brown dwarf is as bright as the Sun today in X-ray light, while it is fifty times less massive than the Sun", said Tsuboi.<ref name=Williams2003/> "This observation, thus, raises the possibility that even massive planets might emit X-rays by themselves during their youth!"<ref name=Williams2003/> {{clear}} ==Heliophysics== {{main|Stars/Sun/Heliophysics|Heliophysics}} "Heliophysics is concerned with laws that give rise to structures and processes that occur in magnetized plasmas and in neutral environments in the local cosmos, both temporal (weather-like) and persistent (climate-like). These laws systematize the results of half a century of exploring space that followed centuries of ground-based observations. During this time spacecraft have imaged the Sun over many wavelengths and resolutions. They have visited every planet, all major satellites and many minor ones, and a selection of comets and asteroids. Beyond this they have traversed the expanse of the [[heliosphere]] itself. Out of the vast store of data so accumulated, the laws and principles of heliophysics are emerging to describe structures that are natural to magnetized plasmas and neutrals in cosmic settings and to specify principles that make the heliosphere a realm of numerous, original dynamical modes."<ref name=Siscoe>{{ cite book |author=George L. Siscoe |author2=Carolus J. Schrijver |title=Perspective on heliophysics, In: ''Heliophysics: Space Storms and Radiation: Causes and Effects'' |publisher=Cambridge University Press |location=Cambridge, UK |date=May 2010 |editor=Carolus J. Schrijver |editor2=George L. Siscoe |pages=1-10 |url=http://www.langtoninfo.com/web_content/9780521760515_excerpt.pdf |arxiv= |bibcode= |doi= |pmid= |isbn=978-0-521-76051-5 |accessdate=2014-08-02 }}</ref> "In the case of heliophysics, probably most of its laws have yet to be discovered, since the project of finding them is young. Moreover, heliophysics is a unique hybrid between meteorology and astrophysics with substantial components of physics and chemistry. Thus, many of the laws of heliophysics that we can list at this time might be subjects for research in meteorology (e.g. the field of aeronomy), astrophysics (e.g. shock waves and cosmic rays), physics (e.g. magnetic reconnection and particle energization), or chemistry (e.g. reaction rates in planetary ionospheres and thermospheres)."<ref name=Siscoe/> ==Magnetohydrodynamics== "When magnetic fields "reconnect" in a turbulent magnetohydrodynamic (MHD) plasma, electric fields are generated in which particles can be accelerated (Matthaeus ''et al.'', 1984; Sorrell, 1984)."<ref name="Gaisser">{{cite book |author=Thomas K. Gaisser |title=Cosmic Rays and Particle Physics |publisher=Cambridge University Press |location= |year=1990 |editor= |pages=279 |url=http://books.google.com/books?hl=en&lr=&id=qJ7Z6oIMqeUC&oi=fnd&pg=PR15&ots=IxjwLxBwXu&sig=voHKIYstBlBYla4jcbur_b-Zwxs |arxiv= |bibcode= |doi= |pmid= |isbn=0521339316 |accessdate=2014-01-11 }}</ref> ==Stellar sciences== {{main|Stars/Sciences}} [[Image:November 3 2009 GOES14 Image.png|thumb|right|250px|The GOES 14 spacecraft took this image of the '''Sun'''. Credit: NOAA/Space Weather Prediction Center and the NWS Internet Services Team.]] The GOES 14 spacecraft carries a Solar X-ray Imager that took this image [at right] of the '''Sun''' during the most recent quiet period. The Sun appears dark because of the wavelength band of observation and the lack of X-rays. Except for X-ray emission that suggests a circular disc with some isolated X-ray sources at specific locations, the Sun is almost invisible. X-rays are primarily emitted from plasmas near 10⁶ K. {{clear}} ==See also== {{div col|colwidth=20em}} * [[Plasmas/Plasma objects/Coronal clouds|Coronal clouds]] * [[Radiation/Cosmic rays|Cosmic-ray astronomy]] * [[Radiation astronomy/Electrons|Electron astronomy]] * [[Radiation astronomy/Fieries|Fiery meteor astronomy]] * [[Stars/Flares|Flare stars]] * [[Stars/Sun/Heliophysics|Heliophysics]] * [[Radiation astronomy/Lightnings|Lightning astronomy]] * [[Radiation astronomy/Nebulas|Nebula astronomy]] * [[Stars/Nova-likes|Nova-like stars]] * [[Stars/Novas|Novas]] * [[Stars/Os|O-type stars]] * [[Radiation astronomy/Protons|Proton astronomy]] * [[Stars/Quasars|Quasars]] * [[Stars/Star fissions|Star fissions]] * [[Stars/Active regions|Stellar active regions]] * [[Stars/Surface fusion|Surface fusions]] * [[Stars/Supernovas|Supernovas]] * [[Stars/Variables|Variable stars]] * [[Stars/Wolf-Rayets|Wolf-Rayet stars]] * [[Stars/X-rays|X-ray stars]] {{Div col end}} ==References== {{reflist|2}} ==External links== * [http://www.adsabs.harvard.edu/ The SAO/NASA Astrophysics Data System] * [http://simbad.u-strasbg.fr/simbad/ SIMBAD Astronomical Database] <!-- footer templates --> {{Radiation astronomy resources}}{{Sisterlinks|Plasma radiation astronomy}} <!-- footer categories --> [[Category:Radiation astronomy/Lectures]] pmaz5givmk04a2b6c197d0z1gp2yn2x 2414027 2413996 2022-08-13T05:53:14Z Marshallsumter 311529 wikitext text/x-wiki [[Image:Media 1.ogv|thumb|right|250px|On July 19, 2012, an eruption occurred on the sun that produced a moderately powerful solar flare and a dazzling magnetic display known as coronal rain. Credit: NASA Goddard Space Flight Center, Music: 'Thunderbolt' by Lars Leonhard, courtesy of artist.{{tlx|free media}}]] A [[coronal cloud]] is a cloud, or cloud-like, natural astronomical entity, composed of plasma and usually associated with a star or other astronomical object where the temperature is such that X-rays are emitted. While small coronal clouds are above the photosphere of many different visual spectral type stars, others occupy parts of the [[interstellar medium]] (ISM), extending sometimes millions of kilometers into space, or thousands of light-years, depending on the size of the associated object such as a galaxy. {{clear}} ==Auroras== {{main|Plasmas/Plasma objects/Auroras}} [[Image:Aurora Iceland 2015 Carlos Gauna 625.jpg|thumb|right|300px|This dramatic panorama shows a colourful, shimmering auroral curtain reflected in a placid Icelandic lake. Credit: Carlos Gauna. {{tlx|fairuse}}]] '''Auroras''' can be caused by electrons being absorbed into an atmosphere. The "dramatic panorama [on the right shows a colorful], shimmering auroral curtain reflected in a placid Icelandic lake. The image was taken on 18 March 2015 by Carlos Gauna, near Jökulsárlón Glacier Lagoon in southern Iceland."<ref name=ESAGauna>{{ cite book |author=European Space Agency |title=Aurora over Icelandic Lake |publisher=ESA |location= |date=9 April 2015 |url=http://sci.esa.int/cluster/55767-aurora-over-icelandic-lake/ |accessdate=2015-04-12 }}</ref> "The celestial display was generated by a coronal mass ejection, or CME, on 15 March. Sweeping across the inner Solar System at some 3 million km per hour, the eruption reached Earth, 150 million kilometres away, in only two days. The gaseous cloud collided with Earth’s magnetic field at around 04:30 GMT on 17 March."<ref name=ESAGauna/> "When the charged particles from the Sun penetrate Earth's magnetic shield, they are channelled downwards along the magnetic field lines until they strike atoms of gas high in the atmosphere. Like a giant fluorescent neon lamp, the interaction with excited oxygen atoms generates a green or, more rarely, red glow in the night sky, while excited nitrogen atoms yield blue and purple colours."<ref name=ESAGauna/> "Auroral displays are not just decorative distractions. They are most frequent when the Sun's activity nears its peak roughly every 11 years. At such times, the inflow of high-energy particles and the buffeting of Earth’s magnetic field may sometimes cause power blackouts, disruption of radio communications, damage to satellites and even threaten astronaut safety."<ref name=ESAGauna/> {{clear}} ==Coronas== [[Image:PSM V60 D316 The solar corona.png|thumb|right|250px|The solar corona is photographed between 1901-2. Credit: [http://www.archive.org/details/popularsciencemo60newy Popular Science Monthly Volume 60].{{tlx|free media}}]] [[Image:Cp19halphajune29.png|thumb|left|250px|This is a coronagraph/polarimeter image of the solar corona on June 29, 1980, in H alpha light. Credit: NASA.{{tlx|free media}}]] '''Def.''' "[t]he luminous plasma atmosphere of the Sun or other star, extending millions of kilometres into space, most easily seen during a total solar eclipse"<ref name=CoronaWikt>{{ cite web |title=corona |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=6 September 2015 |url=https://en.wiktionary.org/wiki/corona |accessdate=2015-09-10 }}</ref> is called a '''corona''', or '''stellar corona'''. "Beginning with the daguerreotype of the corona of 1851, the Reverend Lecturer had thrown on the screen pictures illustrating the form of the corona in different years. The drawings of those of 1867, 1878, and 1900 all showed long equatorial extensions with openings at the solar poles filled with beautiful rays."<ref name=Cortie>{{ cite journal |author=A. L. Cortie |title=Synopsis of Lecture on "The Solar Corona" by the Rev. A.L. Cortie to the Members of the North-Western Branch (Manchester) on 7th November 1900 |journal=Journal of the British Astronomical Association |month=December |year=1900 |volume=11 |issue=12 |pages=77-8 |url=http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1900JBAA...11...77C&link_type=ARTICLE&db_key=AST&high= |arxiv= |bibcode=1900JBAA...11...77C |doi= |pmid= |accessdate=2011-11-09 }}</ref> "The intermediate years, as, for example, 1883, 1886, and 1896 showed the four groups of synclinals which mainly constitute the corona gradually descending towards the equator of the sun, with a corresponding opening of the polar regions."<ref name=Cortie/> "Some of the theories of the solar corona were then illustrated and discussed."<ref name=Cortie/> # "The corona is not of the nature of an atmosphere round the sun, for the pressure at the sun's limb would be enormous, while the thinness of the chromospheric lines show that it is not."<ref name=Cortie/> # "comets, such as that of 1843, have approached the sun with enormous velocities within the region of the prominences without suffering disruption or retardation."<ref name=Cortie/> # "If not an atmosphere of particles of gas, still less is it an atmosphere of solid stones or meteorites."<ref name=Cortie/> # "Meteor streams do circle round the sun, but there is no reason why the positions of the orbits, or the intrinsic brightness of such streams should vary with the sun-spot period."<ref name=Cortie/> # "the appearance of the corona does not seem to be such as the projection of meteor streams upon the celestial vault would give."<ref name=Cortie/> # "Prof. Schaeberle has proposed a mechanical origin of the solar corona, due to the forces of ejection of particles from the solar limb, as evidenced by the prominences, and the force of gravity under the particular conditions of the solar rotation and the inclination of its axis to the earth's orbit."<ref name=Cortie/> # "The electrical theory of the corona does not negative the mechanical theory, but supplements it. In addition to the forces of gravity and ejection, it takes account of the repulsive force which the sun exerts on matter which has the same electrical sign as itself, and which has been ejected from it."<ref name=Cortie/> # "it would seem that the solar corona is of the nature of an electrical aurora round the sun."<ref name=Cortie/> # "the coronoidal discharges in poor vacua obtained by Prof. Pupin about an insulated metal ball are exceedingly like the rays and streamers of the solar corona."<ref name=Cortie/> The Sun's hot corona continuously expands in space creating the solar wind, a stream of charged particles that extends to the heliopause at roughly 100 astronomical units. The bubble in the [[interstellar medium]] formed by the solar wind, the heliosphere, is the largest continuous structure in the Solar System.<ref>{{ cite web |date=22 April 2003 |title=A Star with two North Poles |url=http://science.nasa.gov/headlines/y2003/22apr_currentsheet.htm |work=Science @ NASA |publisher=NASA }}</ref><ref name=Riley>{{ cite journal |last=Riley |first=P. |last2=Linker |first2=J. A. |last3=Mikić |first3=Z. |year=2002 |title=Modeling the heliospheric current sheet: Solar cycle variations |url=http://ulysses.jpl.nasa.gov/science/monthly_highlights/2002-July-2001JA000299.pdf |journal=Journal of Geophysical Research |volume=107 |issue=A7 |pages=SSH 8–1 |bibcode=2002JGRA.107g.SSH8R |doi=10.1029/2001JA000299 |id=CiteID 1136 }}</ref> The sun's corona is constantly being lost to space, creating what is essentially a very thin atmosphere throughout the [[Solar System]]. The movement of mass ejected from the Sun is known as the solar wind. Inconsistencies in this wind and larger events on the surface of the star, such as coronal mass ejections, form a system that has features analogous to conventional weather systems (such as pressure and wind) and is generally known as space weather. Coronal mass ejections have been tracked as far out in the [[solar system]] as Saturn.<ref name=Christensen>Bill Christensen. [http://www.space.com/businesstechnology/technology/technovel_shock_041105.html Shock to the (Solar) System: Coronal Mass Ejection Tracked to Saturn.] Retrieved on 28 June 2008.</ref> The activity of this system can affect planetary atmospheres and occasionally surfaces. The interaction of the solar wind with the terrestrial atmosphere can produce spectacular aurorae,<ref name=AlaskaReport>AlaskaReport. [http://alaskareport.com/science10043.htm What Causes the Aurora Borealis?] Retrieved on 28 June 2008.</ref> and can play havoc with electrically sensitive systems such as electricity grids and radio signals. {{clear}} ==Coronal arcades== [[Image:Coronal_arcade.png|thumb|right|250px|This is a TRACE image of the coronal arcade structure in the flare on Bastille Day, 1998. Credit: NASA.{{tlx|free media}}]] '''Def.''' a close collection of loops in a cylindrical structure is called an '''arcade'''. The TRACE image at right "is from near flare maximum (11:00 UT) and has a width of 230,000 km [...] how in the world can the footpoints of the arcade have such a clearly-organized pattern whose scale greatly exceeds the known scales of the largest convective scales known in the photosphere?"<ref name=Handy>{{ cite book |author=Brian Handy, Hugh Hudson |title=Super Regions |publisher=University of Montana |location=Helena, Montana, USA |date=July 14, 2000 |url=http://solar.physics.montana.edu/nuggets/2000/000714/000714.html |accessdate=2012-11-09 }}</ref> "The most obvious coronal signatures of CMEs in the low corona are the arcades of bright loops that develop after the CME material has erupted [...] nearly all (92%) EIT post-eruptive arcades from 1997 – 2002 were associated with LASCO CMEs [...] The activity associated with halo CMEs includes the formation of dimming regions, long-lived loop arcades, flaring active regions, large-scale coronal waves and filament eruptions".<ref name=Webb>{{ cite journal |author=David F. Webb, Timothy A. Howard |title=Coronal Mass Ejections: Observations |journal=Living Reviews in Solar Physics |year=2012 |volume=9 |issue= |pages=3 |url=http://www.boulder.swri.edu/~howard/Papers/2012_lrsp.pdf |arxiv= |bibcode= |doi= |pmid= |accessdate=2012-11-11 }}</ref> {{clear}} ==Coronal clouds== [[Image:2011 03 sun030311.jpg|thumb|right|200px|This image is taken in Hα of the Sun and above showing a cloud above a sunspot. Credit: Alan Friedman.{{tlx|fairuse}}]] "Coronal clouds, type IIIg, form in space above a spot area and rain streamers upon it."<ref name=Pettit43>{{ cite journal |author=Edison Pettit |title=The Properties of Solar Prominences as Related to Type |journal=Astrophysical Journal |month=July |year=1943 |volume=98 |issue=7 |pages=6-19 |url= |bibcode=1943ApJ....98....6P |doi=10.1086/144539 |pmid= |accessdate=2011-08-01 }}</ref> "[C]oronal magnetic bottles, produced by flares, [may] serve as temporary traps for solar cosmic rays ... It is the expansion of these bottles at velocities of 300–500 km/s which allows fast azimuthal propagation of solar cosmic rays independent of energy. A coronagraph on [[w:OSO 7|Os 7]] observed a coronal cloud which was associated with bifurcation of the underlying coronal structure."<ref name="Schatten">{{cite journal |author=K. H. Schatten, D. J. Mullan |title=Fast azimuthal transport of solar cosmic rays via a coronal magnetic bottle |journal=Journal of Geophysical Research |month=December 1, |year=1977 |volume=82 |issue=35 |pages=5609-20 |url=http://www.agu.org/pubs/crossref/1977/JA082i035p05609.shtml |arxiv= |bibcode= |doi=10.1029/JA082i035p05609 |pmid= |accessdate=2013-07-07 }}</ref> In a coronal cloud are [[Magnetohydrodynamics|magnetohydrodynamic]] plasma flux tubes along magnetic field lines.<ref name=Aschwanden/> {{clear}} ==Coronal heating== "The photosphere of the Sun has an effective temperature of 5,570 K<ref name=Massey>{{ cite journal |author=Massey P |author2=Silva DR |author3=Levesque EM |author4=Plez B |author5=Olsen KAG |author6=Clayton GC |author7=Meynet G |author8=Maeder A |title=Red Supergiants in the Andromeda Galaxy (M31) |journal=The Astrophysical Journal |volume=703 |year=2009 |issue=1 |page=420 |doi=10.1088/0004-637X/703/1/420 |bibcode=2009ApJ...703..420M }}</ref> yet its corona has an average temperature of 1–2 x 10⁶ K.<ref name=Erdelyi>{{ cite journal |author=Erdèlyi R |author2=Ballai I |title=Heating of the solar and stellar coronae: a review |year=2007 |journal=Astron Nachr |volume=328 |issue=8 |page=726 |doi=10.1002/asna.200710803 |bibcode=2007AN....328..726E }}</ref> However, the hottest regions are 8–20 x 10⁶ K.<ref name=Erdelyi/> The high temperature of the corona shows that it is heated by something other than direct [[w:Heat conduction|heat conduction]] from the photosphere.<ref name=Russell2001>{{ cite book |author=Russell CT |title=Space Weather (Geophysical Monograph) |year=2001 |publisher=American Geophysical Union |chapter=Solar wind and interplanetary magnetic field: A tutorial |editor=Song, Paul |editor2=Singer, Howard J. |editor3=Siscoe, George L. |isbn=9780875909844 |pages=73–88 |url=http://www-ssc.igpp.ucla.edu/personnel/russell/papers/SolWindTutorial.pdf }}</ref> It is thought that the energy necessary to heat the corona is provided by turbulent motion in the convection zone below the photosphere, and two main mechanisms have been proposed to explain coronal heating.<ref name=Erdelyi/> The first is [[w:wave|wave]] heating, in which sound, gravitational or magnetohydrodynamic waves are produced by turbulence in the convection zone.<ref name=Erdelyi/> These waves travel upward and dissipate in the corona, depositing their energy in the ambient gas in the form of heat.<ref name=Alfven>{{ cite journal |author=Alfvén H |title=Magneto-hydrodynamic waves, and the heating of the solar corona |bibcode=1947MNRAS.107..211A |journal=Monthly Notices of the Royal Astronomical Society |volume=107 |page=211 |year=1947 }}</ref> The other is [[w:magnetic field|magnetic]] heating, in which magnetic energy is continuously built up by photospheric motion and released through [[w:magnetic reconnection|magnetic reconnection]] in the form of large [[w:solar flare|solar flare]]s and myriad similar but smaller events—[[w:nanoflares|nanoflares]].<ref name=Parker2>{{ cite journal |author=Parker EN |title=Nanoflares and the solar X-ray corona |journal=The Astrophysical Journal |volume=330 |page=474 |year=1988 |doi=10.1086/166485 |bibcode=1988ApJ...330..474P }}</ref> Currently, it is unclear whether waves are an efficient heating mechanism. All waves except [[w:Alfvén wave|Alfvén wave]]s have been found to dissipate or refract before reaching the corona.<ref name=Sturrock>{{ cite journal |author=Sturrock PA, Uchida Y |title=Coronal heating by stochastic magnetic pumping |journal=The Astrophysical Journal |volume=246 |page=331 |year=1981 |doi=10.1086/158926 |bibcode=1981ApJ...246..331S }}</ref> In addition, Alfvén waves do not easily dissipate in the corona. Current research focus has therefore shifted towards flare heating mechanisms.<ref name=Erdelyi/>"<ref name=XrayAstronomy>{{ cite web |title=X-ray astronomy, In: ''Wikipedia'' |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=June 11, 2012 |url=http://en.wikipedia.org/wiki/X-ray_astronomy |accessdate=2012-06-29 }}</ref> ==Coronal loops== [[Image:AR1520 and Shimmering Coronal Loops.ogv|thumb|250px|right|This movie shows the evolution of active region 1520, including coronal loops. Credit: NASA/Goddard Space Flight Center.{{tlx|free media}}]] [[Image:Traceimage.jpg|thumb|right|250px|This image of coronal loops observed by the Transition Region And Coronal Explorer ([[w:TRACE|TRACE]]) shows that not all rays travel in straight lines. Credit: NASA.{{tlx|free media}}]] Coronal loops have become very important when trying to understand the current ''coronal heating problem''. Coronal loops are highly radiating sources of plasma and therefore easy to observe by instruments such as ''TRACE''; they are highly observable ''laboratories'' to study phenomena such as solar oscillations, wave activity and [[w:Nanoflares|nanoflares]]. However, it remains difficult to find a solution to the coronal heating problem as these structures are being observed remotely, where many ambiguities are present (i.e. radiation contributions along the [line-of-sight propagation] LOS). ''In-situ'' measurements are required before a definitive answer can be arrived at, but due to the high plasma temperatures in the corona, in-situ measurements are impossible (at least for the time being). The next mission of the Nasa [[w:Solar Probe Plus|Solar Probe Plus]] will approach the Sun very closely allowing more direct observations. "The peak continuum intensity was always at the loop tops."<ref name=Zirin1981>{{ cite journal |author=H. Zirin |author2=U. Feldman |author3=G. A. Doschek |author4=S. Kane |title=On the relationship between soft X-rays and Hα-emitting structures during a solar flare |journal=The Astrophysical Journal |month=May 15, |year=1981 |volume=246 |issue=05 |pages=321-30 |url=http://adsabs.harvard.edu/full/1981ApJ...246..321Z |arxiv= |bibcode=1981ApJ...246..321Z |doi=10.1086/158925 |pmid= |accessdate=2013-07-10 }}</ref> The population of coronal loops can be directly linked with the [[w:solar cycle|solar cycle]]; it is for this reason coronal loops are often found with sunspots at their footpoints. Coronal loops project through the [[w:chromosphere|chromosphere]] and [[w:transition region|transition region]], extending high into the [[Coronal cloud|corona]]. Coronal loops have a wide variety of temperatures along their lengths. Loops existing at temperatures below 1&nbsp;MK are generally known as cool loops, those existing at around 1&nbsp;MK are known as warm loops, and those beyond 1&nbsp;MK are known as hot loops. Naturally, these different categories radiate at different wavelengths.<ref name=Vourlidas>{{cite journal | author = A. Vourlidas |author2=J. A. Klimchuk |author3=C. M. Korendyke |author4=T. D. Tarbell |author5=B. N. Handy | title = On the correlation between coronal and lower transition region structures at arcsecond scales | journal = The Astrophysical Journal | volume = 563 | issue = 1 | pages = 374–80 | year = 2001 | doi = 10.1086/323835 | bibcode=2001ApJ...563..374V }}</ref> Coronal loops populate both active and quiet regions of the solar surface. Active regions on the solar surface take up small areas but produce the majority of activity and 82% of the total coronal heating energy.<ref name=Aschwanden>{{ cite journal | author = M. J. Aschwanden | title = An evaluation of coronal heating models for Active Regions based on Yohkoh, SOHO, and TRACE observations | journal = The Astrophysical Journal | volume = 560 | issue = 2 | pages = 1035–44 | year = 2001 | doi = 10.1086/323064 | bibcode=2001ApJ...560.1035A }}</ref> The quiet Sun, although less active than active regions, is awash with [[w:dynamics (mechanics)|dynamic]] processes and [[w:transient astronomical event|transient]] events (bright points, nanoflares and jets).<ref name=Aschwanden04>{{ cite book | author = M. J. Aschwanden | title = Physics of the Solar Corona. An Introduction | publisher = Praxis Publishing Ltd. | date = 2004 | isbn = 3-540-22321-5 }}</ref> As a general rule, the quiet Sun exists in regions of closed magnetic structures, and active regions are highly dynamic sources of explosive events. It is important to note that observations suggest the whole corona is massively populated by open and closed magnetic fieldlines. A closed fieldline does not constitute a coronal loop; however, closed flux must be ''filled with plasma'' before it can be called a coronal loop. The image at right shows particle rays leaving the surface of the Sun (darker ends of the loops), traveling in a loop controlled by a local magnetic field similar to how particle accelerators accelerate, steer, and aim a stream of particles at a target (the much brighter regions in the chromosphere). The loops have a temperature of approximately 10⁶ K and are emitting X-rays (synchrotron and cyclotron radiation). Coronal loops form the basic structure of the lower corona andtransition region of the Sun. These highly structured and elegant loops are a direct consequence of the twisted solar magnetic flux within the solar body. The population of coronal loops can be directly linked with the solar cycle; it is for this reason coronal loops are often found with sunspots at their footpoints. The upwelling magnetic flux pushes through the photosphere, exposing the cooler plasma below. Loops of magnetic flux (closed flux tubes) well up from the solar body and fill with hot solar plasma.<ref name=Katsukawa>{{ cite journal |author=Yukio Katsukawa |author2=Saku Tsuneta |title=Magnetic Properties at Footpoints of Hot and Cool Loops |journal=The Astrophysical Journal |month=March |year=2005 |volume=621 |issue=1 |pages=498-511 |url=http://iopscience.iop.org/0004-637X/621/1/498/pdf/0004-637X_621_1_498.pdf |arxiv= |bibcode=2005ApJ...621..498K |doi=10.1086/427488 |pmid= |accessdate=2011-12-09 }}</ref> Due to the heightened magnetic activity in these coronal loop regions, coronal loops can often be the precursor to solar flares and coronal mass ejections (CMEs). {{clear}} ==Coronal mass ejections== {{main|Radiation/Meteors}} [[Image:Coronal Mass Ejection.gif|thumb|right|250px|Arcs rise above an active region on the surface of the Sun in this series of images taken by the STEREO (Behind) spacecraft. Credit: Images courtesy of the NASA STEREO Science Center.{{tlx|free media}}]] '''Def.''' a "massive burst of solar wind, other light isotope plasma, and magnetic fields rising above the solar corona or being released into space"<ref name=CoronalMassEjectionWikt>{{ cite book |title=coronal mass ejection |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=June 21, 2013 |url=http://en.wiktionary.org/wiki/coronal_mass_ejection |accessdate=2013-07-07 }}</ref> is called a '''coronal mass ejection''' (CME). An explosive limb flare occurred above 30,000 km in the corona of the [[Sun (star)|Sun]].<ref name=Zirin/> "So the aftermath of the flare explosion, usually visible in disk pictures as extensive Hα brightening, but hidden from us in this case, was seen by the ionosphere as an intense flux of ionizing radiation from the coronal cloud created by the explosion."<ref name=Zirin>{{ cite journal |author=Harold Zirin |title=The Limb Flare of November 20, 1960: a Coronal Phenomenon |journal=Astrophysical Journal |month=October |year=1964 |volume=140 |issue=10 |pages=1216-35 |url= |bibcode=1964ApJ...140.1216Z |doi=10.1086/148019 |pmid= |accessdate=2011-08-01 }}</ref> "The November 20, 1960, event is very similar to that of February 10, 1956, which was observed at Sacramento Peak. A bright ball appears above the surface, grows in size and Hα brightness, and explodes upward and outward."<ref name=Zirin/> "The great breadth and intensity of the Hα emission from the suspended ball at 2013 U.T. testify to the large amount of energy stored there, as no corresponding macroscopic motion was observed until the explosion at 2023 U.T."<ref name=Zirin/> "[T]he great energy of the preflare cloud was released into the corona by the explosion of 2023 U.T., and Hα radiation disappeared by 2035 U.T."<ref name=Zirin/> "On 16 June 1972, the [[w:Naval Research Laboratory|Naval Research Laboratory]]'s coronagraph aboard [[w:OSO-7|OSO-7]] tracked a huge coronal cloud moving outward from the [[Sun (star)|Sun]]."<ref name=Koomen>{{ cite journal |author=Martin Koomen |author2=Russell Howard |author3=Richard Hansen |author4=Shirley Hansen |title=The coronal transient of 16 June 1972 |journal=Solar Physics |month=February |year=1974 |volume=34 |issue=2 |pages=447-52 |url=http://link.springer.com/article/10.1007/BF00153680 |arxiv= |bibcode= |doi=10.1007/BF00153680 |pmid= |accessdate=2013-07-10 }}</ref> A [[w:coronal mass ejection|coronal mass ejection]] (CME) is an ejected plasma consisting primarily of electrons and [[w:proton|proton]]s (in addition to small quantities of heavier elements such as helium, oxygen, and iron), plus the entraining coronal closed magnetic field regions. Evolution of these closed magnetic structures in response to various photospheric motions over different time scales (convection, differential rotation, meridional circulation) somehow leads to the CME.<ref name=Gopalswamy>{{ cite journal |author=Gopalswamy N |author2=Mikic Z |author3=Maia D |author4=Alexander D |author5=Cremades H |author6=Kaufmann P |author7=Tripathi D |author8=Wang YM |title=The pre-CME Sun |journal=Space Sci Rev |year=2006 |volume=123 |issue=1–3 |page=303 |doi=10.1007/s11214-006-9020-2 |bibcode = 2006SSRv..123..303G }}</ref> Small-scale energetic signatures such as plasma heating (observed as compact soft X-ray brightening) may be indicative of impending CMEs. The soft X-ray sigmoid (an S-shaped intensity of soft X-rays) is an observational manifestation of the connection between coronal structure and CME production.<ref name=Gopalswamy/> "Relating the sigmoids at X-ray (and other) wavelengths to magnetic structures and current systems in the solar atmosphere is the key to understanding their relationship to CMEs."<ref name=Gopalswamy/> {{clear}} ==Coronal streamers== [[Image:Parker Solar Probe coronal stream wispr-big 1-st flyby.jpg|thumb|right|250px|This image from Parker Solar Probe's WISPR (Wide-field Imager for Solar Probe) instrument shows a coronal streamer, seen over the east limb of the Sun on Nov. 8, 2018, at 1:12 a.m. EST. Credit: NASA/NRL/Parker Solar Probe.{{tlx|free media}}]] The '''interconnections of active regions''' are arcs connecting zones of opposite magnetic field, in different active regions. Significant variations of these structures are often seen after a flare. Some other features of this kind are [[w:helmet streamer|helmet streamer]]s—large cap-like coronal structures with long pointed peaks that usually overlie sunspots and active regions. Coronal streamers are considered as sources of the slow [[w:solar wind|solar wind]].<ref name=Ofman>{{ cite journal | doi= 10.1029/2000GL000097 | last= Ofman | first= Leon | title= Source regions of the slow solar wind in coronal streamers | journal= Geophysical Research Letters | volume = 27 | issue= 18 | pages= 2885–8 |year=2000 | bibcode=2000GeoRL..27.2885O }}</ref> Coronal streamers are structures of solar material within the Sun's atmosphere, the corona, that usually overlie regions of increased solar activity. The fine structure of the streamer in the image on the right is very clear, with at least two rays visible. Parker Solar Probe was about 16.9 million miles from the Sun's surface when this image was taken. The bright object near the center of the image is Mercury, and the dark spots are a result of background correction. {{clear}} ==Dynamos== [[Image:SolarCycle25 Prediction Bhowmik Nandy 2018.jpg|thumb|right|250px|This figure is the outcome of the first ever century-scale, data driven, coupled solar surface flux transport model and solar internal dynamo model simulation which was utilized to predict the amplitude and timing of sunspot cycle 25. Credit: [[c:user:Idnan007|Idnan007]].{{tlx|free media}}]] "A plasma with local magnetohydrodynamic instabilities creates mechanical turbulence, motion, or shear (a dynamo) which in turn generates or sustains the local magnetic field."<ref name=RadiativeDynamo>{{ cite web |title=Radiative dynamo |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=June 30, 2012 |url=http://en.wikiversity.org/wiki/Radiative_dynamo |accessdate=2012-07-06 }}</ref> This prediction in the image on the right<ref name=Bhowmik>“Prediction of the strength and timing of sunspot cycle 25 reveal decadal-scale space environmental conditions”, Bhowmik, P., and Nandy, D. 2018, Nature Communications, 9, 5209 (https://www.nature.com/articles/s41467-018-07690-0)</ref> indicates that solar cycle 25 would be a weak, but not insignificant cycle. The ensemble prediction ranges from a cycle slightly weaker to slightly stronger compared to solar cycle 24. {{clear}} ==Electromagnetics== {{main|Radiation astronomy/Electromagnetics}} [[Image:Latest xrt soft x-ray.gif|thumb|right|250px|The Sun in the soft X-rays is seen by the Hinode X-ray Telescope (XRT) on October 15, 2009. Credit: Joseph B. Gurman, Facility Scientist, Solar Data Analysis Center, ISAS/JAXA and NASA.{{tlx|free media}}]] "The first systematic attempt to base a theory of the origin of the solar system on electromagnetic or hydromagnetic effects was made in Alfvén (1942). The reason for doing so was that a basic difficulty with the old Laplacian hypothesis: how can a central body (Sun or planet) transfer angular momentum to the secondary bodies (planets or satellites) orbiting around it? It was demonstrated that this could be done by electromagnetic effects. No other acceptable mechanism has yet been worked out. [...] the electromagnetic transfer mechanism has been confirmed by observations, as described in the monograph ''Cosmic Plasma'' (Alfvén, 1981, pp. 28, 52, 53 0."<ref name=Alfven1981>{{ cite journal |author=Hannes Alfvén |title=The Voyager 1/Saturn Encounter and the Cosmogonic Shadow Effect |journal=Astrophysics and Space Science |month=October |year=1981 |volume=79 |issue=2 |pages=491-505 |url=http://adsabs.harvard.edu/abs/1981Ap&SS..79..491A |arxiv= |bibcode=1981Ap&SS..79..491A |doi=10.1007/BF00649444 |pmid= |accessdate=2013-12-19 }}</ref> "If charged particles (electrons, ions or charged grains) move in a magnetic dipole field - strong enough to dominate their motion - under the action of gravitation and the centrifugal force, they will find an equilibrium in a circular orbit if their centrifugal force is 2/3 of the gravitational force [...] The consequence of this is that if they become neutralized, so that electromagnetic forces disappear, the centrifugal force is too small to balance the gravitation. Their circular orbit changes to an elliptical orbit with the semi-major axis ''a'' = 3/4''a''₀ and ''e'' = 1/3 (where ''a''₀ is the central distance where the neutralization takes place [...] Collisional (viscous) interaction between the condensed particles will eventually change the orbit into a new circular orbit with ''a'' = 2/3''a''₀ and ''e'' = 0."<ref name=Alfven1981/> "If [...] there is plasma in the region [collisional interaction results in] matter in the 2/3-[region]. [...] matter in the region [...] will produce a [cosmogonic] ''shadow'' in the region".<ref name=Alfven1981/> On the right is a soft X-ray image in the titanium-polyimide ("Ti_poly") filter from the Hinode X-Ray Telescope (XRT) obtained at: 2009/10/15 18:03 UTC. "The primary filter for the sigmoid observations was the “thin-aluminum/polyimide” (or “Al/poly”) filter, imaging plasmas with temperature of roughly 2–5 MK in the active region."<ref name=McKenzie>{{ cite journal |author=D. E. McKenzie and R. C. Canfield |title=Hinode XRT observations of a long-lasting coronal sigmoid |journal=Astronomy & Astrophysics |month= |year=2008 |volume=481 |issue= |pages=L65–L68 |url=http://www.aanda.org/articles/aa/pdf/2008/13/aa9035-07.pdf |arxiv= |bibcode= |doi=10.1051/0004-6361:20079035 |pmid= |accessdate=2016-11-03 }}</ref> {{clear}} ==Electron winds== As of December 5, 2011, "Voyager 1 is about ... 18 billion kilometers ... from the [S]un [but] the direction of the magnetic field lines has not changed, indicating Voyager is still within the heliosphere ... the outward speed of the solar wind had diminished to zero in April 2010 ... inward pressure from interstellar space is compacting [the magnetic field] ... Voyager has detected a 100-fold increase in the intensity of high-energy electrons from elsewhere in the galaxy diffusing into our solar system from outside ... [while] the [solar] wind even blows back at us."<ref name=Cole>{{ cite web |author=Steve Cole |author2=Jia-Rui C. Cook |author3=Alan Buis |title=NASA's Voyager Hits New Region at Solar System Edge |publisher=NASA |location=Washington, DC |date=December 2011 |url=http://www.nasa.gov/home/hqnews/2011/dec/HQ_11-402_AGU_Voyager.html |accessdate=2012-02-09 }}</ref> ==Flares== [[Image:06 Major Solar Flare (2820012601).jpg|thumb|right|250px|The solar flare shown in this image was captured on December 13, 2006. Credit: [https://www.flickr.com/people/11304375@N07 Image Editor].{{tlx|free media}}]] "[A] medium-strength flare erupted from the sun on July 19, 2012. The blast also generated the enormous, shimmering plasma loops, which are an example of a phenomenon known as "coronal rain," agency officials said."<ref name=WallRain>{{ cite book |author=Mike Wall |title=Super-Hot Plasma 'Rain' Falls on Sun in Amazing Video |publisher=Yahoo! News |location= |date=February 21, 2013 |url=http://news.yahoo.com/super-hot-plasma-rain-falls-sun-amazing-video-190147271.html |accessdate=2013-02-23 }}</ref> "The ... solar proton flare on 20 April 1998 at W 90° and S 43° (9:38 UT) was measured by the GOES-9-satellite (Solar Geophysical Data 1998), as well as by other experiments on WIND ... and GEOTAIL. Protons were accelerated up to energies > 110 MeV and are therefore able to hit the surface of Mercury."<ref name="Kirsch">{{cite book |author=E. Kirsch |author2=U.A. Mall |author3=B. Wilken |author4=G. Gloeckler |author5=A.B. Galvin |author6=K. Cierpka |title=Detection of Pickup- and Sputter Ions by Experiment SMS on the WIND-S/C After a Mercury Conjunction, In: ''Proceedings of the 26th International Cosmic Ray Conference'' |publisher=International Union of Pure and Applied Physics (IUPAP) |location=Salt Lake City, Utah, USA |date=August 17, 1999 |editor=D. Kieda |editor2=M. Salamon |editor3=B. Dingus |pages=212-5 |url= |arxiv= |bibcode=1999ICRC....6..212K |doi= |pmid= |isbn= }}</ref> Hinode's Solar Optical Telescope (SOT) provides crystal-clear images of features on the sun's surface. This image on the right shows a whirl of a new developing sunspot colliding with an existing spot that explodes into a major solar flare. The solar flare shown was captured on December 13, 2006. The flare produced high-energy protons that reached the Earth at the time of STS-116 Space Shuttle flight. The flare is shown in 3 different wavelengths. {{clear}} ==Flare stars== [[Image:ADLeoLightCurve.png|thumb|right|250px|U, B, V and R band light curves are for a flare on AD Leonis, adapted from Hawley and Pettersen, The Astrophysical Journal, vol 378, pp 725-741, 1991. Credit: [[c:user:PopePompus|PopePompus]].{{tlx|free media}}]] "Flare stars are intrinsically faint, but have been found to distances of 1,000 [[w:light year|light year]]s from Earth.<ref name=Kulkarni>{{ cite journal |author=Kulkarni SR, Rau A |year=2006 |bibcode=2006ApJ...644L..63K |title=The Nature of the Deep Lens Survey Fast Transients |journal=The Astrophysical Journal |doi=10.1086/505423 |volume=644 |issue=1 |pages=L63 |arxiv = astro-ph/0604343 }}</ref> {{clear}} ==Galactic coronas== Although a galactic corona is usually "filled with high-temperature plasma at temperatures of T ≈ 1–2 (MK), ... [h]ot active regions and postflare loops have plasma temperatures of T ≈ 2–40 MK."<ref name=Aschwanden2007>{{ cite journal |author=Markus J. Aschwanden |title=Fundamental Physical Processes in Coronae: Waves, Turbulence, Reconnection, and Particle Acceleration In: ''Waves & Oscillations in the Solar Atmosphere: Heating and Magneto-Seismology'' |journal=Proceedings IAU Symposium |year=2007 |editor=Erdelyi R |volume=3 |issue= S247 |pages=257–68 |arxiv=0711.0007 |url=http://journals.cambridge.org/download.php?file=%2FIAU%2FIAU3_S247%2FS1743921308014956a.pdf&code=7c95b408db74ccbe9f1f376d4cb1ef35 |doi=10.1017/S1743921308014956 }}</ref> "Discussion of the alternative hypothesis of cloud ejection from the equatorial layer of the Galaxy leads to the conclusion that the gaseous halo must be highly turbulent and that the coronal clouds are probably [[w:H I region|H I region]]s".<ref name=Grzedzielski>{{ cite journal |author=Grzędzielski, S. |author2=Stępień, K. |title=On the Cloudy Structure of the Galactic Gaseous Corona |journal=Acta Astronomica |year=1963 |volume=13 |issue= |pages=143-56 |url= |bibcode=1963AcA....13..143G |doi= |pmid= |accessdate=2011-08-01 }}</ref> "One question posed by these previous observations is where the absorption originates. If a coronal cloud, the cloud is more than 15 kpc from the plane of NGC 3067. This distance is greater than the optical radius of the galaxy, 9.6 kpc (''H'' = 50 km s^-1 Mpc^-1. Furthermore, the narrow line requires that the cloud be cool, in contrast to the wide range of ionization stages detected for the corona of our Galaxy (Savage and deBoer 1981)."<ref name=Rubin>{{ cite journal |author=Rubin V. C. |author2=Thonnard N. T. |author3=Ford W. K. Jr. |title=NGC 3067 - Additional evidence for nonluminous matter |journal=Astronomical Journal |month=March |year=1982 |volume=87 |issue=3 |pages=477-85 |url= |bibcode=1982AJ.....87..477R |doi=10.1086/113120 |pmid= |accessdate=2011-08-01 }}</ref> "But if the cloud originates instead in the disk, and is moving in a circular orbit viewed at an inclination of 68 deg (the inclination of the optical galaxy), then some gas extends at least to 40 kpc, which is over four times the optical radius."<ref name=Rubin/> ==Helmet streamers== [[Image:Helmet streamers at max.gif|thumb|right|250px|An abundance of helmet streamers is shown at solar maximum. Credit: NASA.{{tlx|free media}}]] [[Image:Helmet streamers at min.jpg|thumb|left|250px|Helmet streamers are shown at solar minimum restricted to mid latitudes. Credit: NASA.{{tlx|free media}}]] '''Helmet streamers''' are bright loop-like structures which develop over active regions on the [[Stars/Sun|sun]]. They are closed magnetic loops which connect regions of opposite magnetic polarity. Electrons are captured in these loops, and cause them to glow very brightly. The solar wind elongates these loops to pointy tips. They far extend above most prominences into the [[Coronal cloud|corona]], and can be readily observed during a solar eclipse. Helmet streamers are usually confined to the "streamer belt" in the mid latitudes, and their distribution follows the movement of active regions during the [[w:solar cycle|solar cycle]]. Small blobs of plasma, or "plasmoids" are sometimes released from the tips of helmet streamers, and this is one source of the slow component of the [[w:solar wind|solar wind]]. In contrast, formations with open magnetic field lines are called [[w:coronal holes|coronal holes]], and these are darker and are a source of the fast solar wind. Helmet streamers can also create coronal mass ejections if a large volume of plasma becomes disconnected near the tip of the streamer. {{clear}} ==Ionospheres== [[Image:Ionosphere-Thermosphere Processes.jpg|thumb|right|250px|In this diagram, the prominent features in the ionosphere-thermosphere system and their coupling to the different energy inputs show the complex temporal and spatial phenomena that are generated. Credit: NASA.{{tlx|free media}}]] Upon reaching the top of the [[w:Mesosphere|mesosphere]], the temperature starts to rise, but air pressure continues to fall. This is the beginning of the [[w:ionosphere|ionosphere]], a region dominated by chemical ions. Many of them are the same chemicals such as [[w:nitrogen|nitrogen]] and [[w:oxygen|oxygen]] in the atmosphere below, but an ever increasing number are hydrogen ions ([[w:proton|proton]]s) and helium ions. These can be detected by an ion spectrometer. The process of [[w:ionization|ionization]] removes one or more [[w:electron|electron]]s from a neutral atom to yield a variety of ions depending on the chemical element species and incidence of sufficient energy to remove the electrons. '''Def.''' the "part of the Earth's atmosphere beginning at an altitude of about 50 kilometers [31 miles] and extending outward 500 kilometers [310 miles] or more"<ref name=IonosphereWikt>{{ cite web |author=[[wikt:User:CORNELIUSSEON|CORNELIUSSEON]] |title=ionosphere |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=11 June 2006 |url=https://en.wiktionary.org/wiki/ionosphere |accessdate=2012-09-20 }}</ref> or the "similar region of the atmosphere of another planet"<ref name=IonosphereWikt1>{{ cite web |author=[[wikt:User:RJFJR|RJFJR]] |title=ionosphere |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=15 November 2008 |url=https://en.wiktionary.org/wiki/ionosphere |accessdate=2012-09-20 }}</ref> is called an '''ionosphere'''. "As a spacecraft travels through the solar system, a targeted radio signal sent back to Earth can be aimed through the ionosphere of a nearby planet. Plasma in the ionosphere causes small but detectable changes in the signal that allow scientists to learn about the upper atmosphere."<ref name=Redd>{{ cite web |author=Nola Taylor Redd |title=Meteoroids Change Atmospheres of Earth, Mars, Venus |publisher=Space.com |location= |date=September 4, 2012 |url=http://www.space.com/17440-meteoroids-mars-venus-atmospheres.html |accessdate=2012-09-05 }}</ref> {{clear}} ==Io plasma torus== {{main|Plasmas/Plasma objects/Io}} [[Image:Jupiter magnetosphere schematic.jpg|thumb|right|250px|This is a schematic of Jupiter's magnetosphere and the components influenced by Io (near the center of the image). Credit: John Spencer.{{tlx|free media}}]] The image at right represents "[t]he Jovian magnetosphere [magnetic field lines in blue], including the Io flux tube [in green], Jovian aurorae, the sodium cloud [in yellow], and sulfur torus [in red]."<ref name=Spencer>{{ cite book |author=John Spencer |title=John Spencer's Astronomical Visualizations |publisher=University of Colorado |location=Boulder, Colorado USA |date=November 2000 |url=http://www.boulder.swri.edu/~spencer/digipics.html |accessdate=2013-04-05 }}</ref> "Io may be considered to be a unipolar generator which develops an emf [electromotive force] of 7 x 10⁵ volts across its radial diameter (as seen from a coordinate frame fixed to Jupiter)."<ref name=Goldreich>{{ cite journal |author=Peter Goldreich |author2=Donald Lynden-Bell |title=Io, a jovian unipolar inductor |journal=The Astrophysical Journal |month=April |year=1969 |volume=156 |issue=04 |pages=59-78 |url= |arxiv= |bibcode=1969ApJ...156...59G |doi=10.1086/149947 |pmid= |accessdate=2013-04-05 }}</ref> "This voltage difference is transmitted along the magnetic flux tube which passes through Io. ... The current [in the flux tube] must be carried by keV electrons which are electrostatically accelerated at Io and at the top of Jupiter's ionosphere."<ref name=Goldreich/> "Io's high density (4.1 g cm^-3) suggests a silicate composition. A reasonable guess for its electrical conductivity might be the conductivity of the Earth's upper mantle, 5 x 10^-5 ohm^-1 cm^-1 (Bullard 1967)."<ref name=Goldreich/> As "a conducting body [transverses] a magnetic field [it] produces an induced electric field. ... The Jupiter-Io system ... operates as a unipolar inductor" ... Such unipolar inductors may be driven by electrical power, develop hotspots, and the "source of heating [may be] sufficient to account for the observed X-ray luminosity".<ref name=Wu>{{ cite journal |author=Kinwah Wu |author2=Mark Cropper |author3=Gavin Ramsay |author4=Kazuhiro Sekiguchi |title=An electrically powered binary star? |journal=Monthly Notices of the Royal Astronomical Society |month=March |year=2002 |volume=321 |issue=1 |pages=221-7 |url= |arxiv=astro-ph/0111358 |bibcode=2002MNRAS.331..221W |doi=10.1046/j.1365-8711.2002.05190.x |pmid= |accessdate=2013-04-05 }}</ref> "The electrical surroundings of Io provide another energy source which has been estimated to be comparable with that of the [gravitational] tides (7). A current of 5 x 10⁶ A is ... shunted across flux tubes of the Jovian field by the presence of Io (7-9)."<ref name=Gold>{{ cite journal |author=Thomas Gold |title=Electrical Origin of the Outbursts on Io |journal=Science |month=November |year=1979 |volume=206 |issue=4422 |pages=1071-3 |url= |arxiv= |bibcode=1979Sci...206.1071G |doi=10.1126/science.206.4422.1071 |pmid= |accessdate=2013-04-05 }}</ref> "[W]hen the currents [through Io] are large enough to cause ohmic heating ... currents ... contract down to narrow paths which can be kept hot, and along which the conductivity is high. Tidal heating [ensures] that the interior of Io has a very low eletrical resistance, causing a negligible extra amount of heat to be deposited by this current. ... [T]he outermost layers, kept cool by radiation into space [present] a large resistance and [result in] a concentration of the current into hotspots ... rock resistivity [and] contact resistance ... contribute to generate high temperatures on the surface. [These are the] conditions of electric arcs [that can produce] temperatures up to ionization levels ... several thousand kelvins".<ref name=Gold/> "[T]he outbursts ... seen [on the surface may also be] the result of the large current ... flowing in and out of the domain of Io ... Most current spots are likely to be volcanic calderas, either provided by tectonic events within Io or generated by the current heating itself. ... [A]s in any electric arc, very high temperatures are generated, and the locally evaporated materials ... are ... turned into gas hot enough to expand at a speed of 1 km/s."<ref name=Gold/> {{clear}} ==Local hot bubbles== [[Image:Local_bubble.jpg|thumb|right|250px|The Local Hot Bubble is hot X-ray emitting gas within the Local Bubble pictured as an artist's impression. Credit: NASA.{{tlx|free media}}]] The 'local hot bubble' is a "hot X-ray emitting plasma within the local environment of the Sun."<ref name=Kappes>{{ cite journal |author=M. Kappes |author2=J. Kerp |author3=P. Richter |title=The composition of the interstellar medium towards the Lockman Hole H I, UV and X-ray observations |journal=Astronomy and Astrophysics |month=July |year=2003 |volume=405 |issue=7 |pages=607-16 |url= |arxiv= |bibcode=2003A&A...405..607K |doi=10.1051/0004-6361:20030610 |pmid= |accessdate=2012-01-19 }}</ref> "This coronal gas fills the irregularly shaped local void of matter (McCammon & Sanders 1990) - frequently called the Local Hot Bubble (LHB)."<ref name=Kappes/> "The [X-ray] intensity of the [Local Hot Bubble] LHB varies across the entire sky:"<ref name=Kerp>{{ cite journal |author=J. Kerp |author2=W. B. Burton |author3=R. Egger |author4=M.J. Freyberg |author5=Dap Hartmann |author6=P.M.W. Kalberla |author7=U. Mebold |author8=J. Pietz |title=A search for soft X-ray emission associated with prominent high-velocity-cloud complexes |journal=Astronomy and Astrophysics |month=February |year=1999 |volume=342 |issue=02 |pages=213-32 |url=http://arxiv.org/abs/astro-ph/9810307 |arxiv=astro-ph/9810307 |bibcode=1999A&A...342..213K |doi= |pmid= |accessdate=2013-07-11 }}</ref> : ''I''_LHB = (2.5-8.2) x 10^-4 cts s^-1 arcmin^-2 (Snowden et al. 1998). The galactic X-ray background is produced largely by emission from the Local Hot Bubble which is within 100 parsecs of the Sun. The Local Hot Bubble is within the [[w:Local Bubble|Local Bubble]]. {{clear}} ==Magnetic clouds== A '''magnetic cloud''' is a transient event observed in the [[w:solar wind|solar wind]]. It was defined in 1981 by Burlaga et al. 1981 as a region of enhanced [[w:magnetic field|magnetic field]] strength, smooth rotation of the magnetic field vector and low [[w:proton|proton]] temperature <ref name=Burlaga>Burlaga, L. F., E. Sittler, F. Mariani, and R. Schwenn, "Magnetic loop behind an interplanetary shock: Voyager, Helios and IMP-8 observations" in "Journal of Geophysical Research", 86, 6673, 1981</ref>. Magnetic clouds are a possible manifestation of a [[w:Coronal Mass Ejection|Coronal Mass Ejection]] (CME). The association between CMEs and magnetic clouds was made by Burlaga et al. in 1982 when a magnetic cloud was observed by [[w:Helios probes|Helios-1]] two days after being observed by [[w:Solar Maximum Mission|SMM]]<ref name=Burlaga82>Burlaga, L. F. et al., "A magnetic cloud and a coronal mass ejection" in "Geophysical Research Letter"s, 9, 1317-1320, 1982</ref>. However, because observations near Earth are usually done by a single spacecraft, many CMEs are not seen as being associated with magnetic clouds. The typical structure observed for a fast CME by a satellite such as [[w:Advanced Composition Explorer|ACE]] is a fast-mode [[w:shock wave|shock wave]] followed by a dense (and hot) sheath of plasma (the downstream region of the shock) and a magnetic cloud. Other signatures of magnetic clouds are now used in addition to the one described above: among other, bidirectional superthermal electrons, unusual charge state or abundance of iron, helium, carbon and/or oxygen. The typical time for a magnetic cloud to move past a satellite at the [[w:Lagrange Point|L1]] point is 1 day corresponding to a radius of 0.15 [[w:Astronomical Unit|AU]] with a typical speed of 450&nbsp;km s⁻¹ and magnetic field strength of 20 nT.<ref name=Lepping>Lepping, R. P. et al. "Magnetic field structure of interplanetary magnetic clouds at 1 AU" in "Journal of Geophysical Research", 95, 11957-11965, 1990.</ref> ==Magnetic reconnections== Magnetic reconnection is a physical process in highly conducting plasmas in which the magnetic [[w:topology|topology]] is rearranged and magnetic energy is converted to [[w:kinetic energy|kinetic energy]], [[w:thermal energy|thermal energy]], and [[w:particle acceleration|particle acceleration]]. Magnetic reconnection occurs on timescales intermediate between slow resistive diffusion of the [[w:magnetic field|magnetic field]] and fast [[w:Alfven wave|Alfvénic]] timescales. The qualitative description of the reconnection process is such that magnetic field lines from different [[w:magnetic domain|magnetic domain]]s (defined by the field line connectivity) are spliced to one another, changing their patterns of connectivity with respect to the sources. It is a violation of an approximate conservation law in plasma physics, and can concentrate mechanical or magnetic energy in both space and time. ==Magnetospheres== [[Image:Structure of the magnetosphere LanguageSwitch.svg|thumb|right|250px|Diagram describes the components of the Earth's magnetosphere. Credit: NASA, [[w:User:Akaase|Aaron Kaase]] and [[c:user:Medium69|Medium69]].{{tlx|free media}}]] A '''magnetosphere''' is formed when a stream of charged particles, such as the solar wind, interacts with and is deflected by the magnetic field of a planet or similar body. “Planets which generate magnetic fields in their interiors ... are surrounded by invisible magnetospheres. ... [I]n many respects, the magnetosphere of Venus is a scaled-down version of Earth’s. ... Earth’s magnetosphere is 10 times larger [than that of Venus]”<ref name=Zhang>{{ cite book |author=Tielong Zhang |author2=Håkan Svedhem |title=A magnetic surprise for Venus Express |publisher=European Space Agency |location=The Netherlands |date=April 5, 2012 |url=http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=50246 |accessdate=2012-04-07 }}</ref> {{clear}} ==Microflares== Ultraviolet telescopes such as TRACE and the Solar and Heliospheric Observatory (SOHO)/EIT can observe individual [solar] micro-flares as small brightenings in extreme ultraviolet light.<ref name=Patsourakos>{{ cite journal | doi = 10.1051/0004-6361:20020151 | author =S. Patsourakos, J.-C. Vial | title = Intermittent behavior in the transition region and the low corona of the quiet Sun | journal = Astronomy and Astrophysics | volume = 385 | pages = 1073–1077 | year = 2002 | bibcode=2002A&A...385.1073P }}</ref> ==Nanoflares== [[Image:378877main Nanoflares lg.jpg|thumb|right|250px|"This false-color temperature map shows solar active region AR10923, observed close to center of the sun's disk. Blue regions indicate plasma near 10 million degrees K." Credit: Reale, et al. (2009), NASA.{{tlx|free media}}]] The image at the right shows the first detection of high temperature nanoflares. The false-color temperature map of solar active region AR10923, observed close to center of the sun's disk, contains nanoflare regions (blue, indicating plasma near 10 million degrees K). "Nanoflares are small, sudden bursts of heat and energy. "They occur within tiny strands that are bundled together to form a magnetic tube called a coronal loop," says Klimchuk. Coronal loops are the fundamental building blocks of the thin, translucent gas known as the sun's [[Coronal cloud|corona]]. ... Observations from the NASA-funded X-Ray Telescope (XRT) and Extreme-ultraviolet Imaging Spectrometer (EIS) instruments aboard Hinode reveal that ultra-hot plasma is widespread in solar active regions. The XRT measured plasma at 10 million degrees K, and the EIS measured plasma at 5 million degrees K. "These temperatures can only be produced by impulsive energy bursts,"says Klimchuk ... "Coronal loops are bundles of unresolved strands that are heated by storms of nanoflares." ... when a nanoflare suddenly releases its energy, the plasma in the low-temperature, low-density strands becomes very hot—around 10 million degrees K—very quickly. The density remains low, however, so the emission, or brightness, remains faint. Heat flows from up in the strand, where it's hot, down to the base of the coronal loop, where it's not as hot. This heats up the dense plasma at the loop’s base. Because it is so dense at the base, the temperature only reaches about 1 million degrees K. This dense plasma expands up into the strand. Thus, a coronal loop is a collection of 5-10 million degree K faint strands and 1 million degree K bright strands. "What we see is 1 million degree K plasma that has received its energy from the heat flowing down from the superhot plasma," says Klimchuk. "For the first time, we have detected this 10 million degree plasma, which can only be produced by the impulsive energy bursts of nanoflares.""<ref name=Layton2009>{{ cite web |author=Laura Layton |title=Tiny Flares Responsible for Outsized Heat of Sun's Atmosphere |publisher=NASA GSFC |location=Greenbelt, Maryland, USA |date=August 14, 2009 |url=http://www.nasa.gov/topics/solarsystem/features/nanoflares.html |accessdate=2012-11-18 }}</ref> The idea that nanoflares might heat the corona was put forward by [[w:Eugene Parker|Eugene Parker]] in the 1980s but is still controversial. In particular, ultraviolet telescopes such as [[w:TRACE|TRACE]] and [[w:Solar and Heliospheric Observatory|SOHO]]/EIT can observe individual micro-flares as small brightenings in extreme ultraviolet light,<ref name=Patsourakos/> but there seem to be too few of these small events to account for the energy released into the corona. The additional energy not accounted for could be made up by wave energy, or by gradual magnetic reconnection that releases energy more smoothly than micro-flares and therefore doesn't appear well in the TRACE data. Variations on the micro-flare hypothesis use other mechanisms to stress the magnetic field or to release the energy, and are a subject of active research in 2005. A nanoflare is a very small [[w:solar flare|solar flare]] which happens in the [[w:corona|corona]], the external [[w:atmosphere|atmosphere]] of the [[Stars/Sun|Sun]]. Observations show that the [[w:solar magnetic field|solar magnetic field]], which is frozen into the motion of the [[w:Plasma (physics)|plasma]] opens into semicirculal structures in the corona. These [[w:coronal loops|coronal loops]], which can be seen in the EUV and X-ray images (see the figure on the left), confine very hot plasma, emitting as it were at a temperature of a few million degrees. Many flux tubes are stable for several days on the solar corona in the X-ray images, emitting at steady rate. However flickerings, brightenings, small explosions, bright points, flares and mass eruptions are observed very frequently, especially in [[w:stellar active region|active regions]]. These macroscopic signs of solar activity are considered by astrophysicists as the phenomenology related to events of relaxation of stressed magnetic fields, during which part of the coronal heating is released by current dissipation or [[w:Joule effect|Joule effect]]. These nanoflares might be very tiny flares, so close one to each other, both in time and in space, to heat the corona and to cause all the phenomena due to solar activity. The distribution of the number of flares observed in the hard X-rays is a function of the energy, following a power law with negative spectral index 1.8.<ref name=Datlowe>{{ cite journal | author = D.W. Datlowe |author2=M.J.Elean |author3=H.S. Hudson | title =OSO-7 observations of solar x-rays in the energy range 10?100 keV | journal = Solar Physics | volume = 39 | pages = 155 | year = 1974 | doi = 10.1007/BF00154978 | bibcode=1974SoPh...39..155D }}</ref><ref name=Lin>{{ cite journal |author=Lin R.P. |author2=Schwartz R.A. |author3=Kane S.R. |author4=Pelling R.M. |author5=Hurley K.C. | journal= The Astrophysical Journal | volume= 283 | pages= 421 |doi=10.1086/162321 |title=Solar hard X-ray microflares | bibcode=1984ApJ...283..421L }}</ref><ref name=Dennis>{{ cite journal |author=Brian R. Dennis | year= 1985 | journal= Solar Physics | volume= 100 | pages= 465 |doi=10.1007/BF00158441 |title=Solar hard X-ray bursts | bibcode=1985SoPh..100..465D }}</ref> <ref name=Porter>{{ cite journal | author=Porter J.G. |author2=Fontenla J.M. |author3=Simnett G.M. |journal= The Astrophysical Journal | volume= 438 |pages= 472 | doi=10.1086/175091 | title=Simultaneous ultraviolet and X-ray observations of solar microflares | bibcode=1995ApJ...438..472P }}</ref> If this distribution would have the same spectral index also at lower energies, flares, micro-flares and nanoflares might provide a considerable part of coronal heating. Actually a negative spectral index of the order of 2 is required in order to maintain the [[w:solar corona|solar corona]]. "[T]he importance of the magnetic field is recognized by all the scientists: there is a strict correspondence between the [[w:stellar active region|active regions]], where the irradiated flux is higher (especially in the X-rays), and the regions of intense magnetic field.<ref name=Poletto>{{ cite journal |author=Poletto G |author2=Vaiana GS |author3=Zombeck MV |author4=Krieger AS |author5=Timothy AF |title=A comparison of coronal X-ray structures of active regions with magnetic fields computed from photospheric observations |journal=Solar Physics |date=September 1975 |volume=44 |issue=9 |pages=83–99 |doi=10.1007/BF00156848 |bibcode=1975SoPh...44...83P }}</ref> More energy is released in turbulent regimes when nanoflares happen at much smaller scale-lengths, where non-linear effects are not negligible.<ref name=Rappazzo>{{ cite journal |author= Rappazzo, A. F. |author2=Velli, M. |author3=Einaudi, G. |author4=Dahlburg, R. B. |title=Nonlinear Dynamics of the Parker Scenario for Coronal Heating |journal=The Astrophysical Journal 2008 |volume=677 |issue= 2 |pages= 1348–1366 |bibcode=2008ApJ...677.1348R |doi= 10.1086/528786 }}</ref> In order to heat a region of very high [[w:X-ray|X-ray]] emission, over an area 1" x 1", a nanoflare of 10¹⁷ J should happen every 20 seconds, and 1000 nanoflares per second should occur in a large active region of 10⁵ x 10⁵ km². Flickerings, brightenings, small explosions, bright points, flares and mass eruptions are observed very frequently, especially in [[stellar active region|active regions]]. {{clear}} ==Nova-like stars== {{main|Stars/Nova-likes}} [[Image:V838 Monocerotis expansion.jpg|thumb|right|250px| Successive photos of V838 Monocerotis show the progress of a light echo. Credit: NASA, ESA, H.E. Bond (STScI) and The Hubble Heritage Team (STScI/AURA).{{tlx|free media}}]] The evolution of non-magnetic dwarf novae and nova-like stars can be different from the magnetic systems (polars and intermediate polars).<ref name=Ak/> Magnetic and non-magnetic systems display different kinematical properties since some flow velocities come from magnetically channeled plasma.<ref name=Ak>{{ cite journal |author=T Ak T |author2=S Bilir |author3=S Ak |author4=KB Coskunoglu |author5=Z Eker |title=The age of cataclysmic variables: a kinematic study |journal=New Astronomy |month=August |year=2010 |volume=15 |issue=6 |pages=491-508 |url=http://adsabs.harvard.edu/abs/2010NewA...15..491A |arxiv=0911.3651 |bibcode=2010NewA...15..491A |doi=10.1016/j.newast.2009.11.007 |pmid= |accessdate=2016-09-30 }}</ref> {{clear}} ==Photospheres== The solar photosphere is a "weakly ionized [''n''_i/(''n''_i + ''n''_a)] ~ 10^-4, relatively cold and dense plasma".<ref name=Khodachenko>{{ cite journal |author=M. L. Khodachenko |author2=V. V. Zaitsev |title=Formation of Intensive Magnetic Flux Tubes in a Converging Flow of Partially Ionized Solar Photospheric Plasma |journal=Astrophysics and Space Science |month=March 01, |year=2002 |volume=279 |issue=4 |pages=389-410 |url=http://link.springer.com/article/10.1023/A:1015162131331 |arxiv= |bibcode= |doi=10.1023/A:1015162131331 |pmid= |accessdate=2013-07-17 }}</ref> ==Plages== [[Image:Plage areas chatzistergos 2020.png|thumb|right|250px|Graph that shows how much area in the surface of the Sun is occupied by bright magnetic features called faculae/plage. Credit: Theodosios Chatzistergos.{{tlx|free media}}]] A '''plage''' is a bright region in the [[w:chromosphere|chromosphere]] of [a star], typically found in regions of the chromosphere near [starspots]. The plage regions map closely to the [[w:faculae|faculae]] in the photosphere below, but the latter have much smaller spatial scales. Accordingly plage occurs most visibly near a starspot region. "Plages are formed in the inner parts of flux loops emerging from below. ... In the early stages of active region growth the appearance of the group is symmetric, while a few days later the ''f'' spot may disappear, leaving an extensive plage."<ref name=Zirin1974>{{ cite book |author=H. Zirin |title=The Magnetic Structure of Plages, In: ''Chromospheric Fine Structure'' |publisher=International Astronomical Union |location=Dordrecht |year=1974 |editor=R. Grant Athay |pages=161-75 |url= |arxiv= |bibcode=1974IAUS...56..161Z |doi= |pmid= |isbn= }}</ref> "[M]ajor changes in active regions only take place in the following ways: # [starspot] formation and break up; # flux outflow from [starspots]; # new flux emergence; and # magnetic reconnection."<ref name=Zirin1974/> "In general there is no proper motion at all in the plage or the surrounding plagettes except for the latter two."<ref name=Zirin1974/> {{clear}} ==Plasma objects== {{main|Plasmas/Plasma objects|Plasma objects}} '''Plasma''' is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms (reduce or increase the number of electrons in them), thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions.<ref name=Luo>{{ cite journal |author=Q-Z Luo |author2=N. D'Angelo |author3=R. L. Merlino | year=1998 |title=Shock formation in a negative ion plasma |journal= |volume=5 |issue=8 |publisher=Department of Physics and Astronomy |url=http://www.physics.uiowa.edu/~rmerlino/nishocks.pdf |accessdate=2011-11-20}}</ref> For plasma to exist, ionization is necessary. The term "plasma density" by itself usually refers to the "electron density", that is, the number of free electrons per unit volume. The degree of ionization of a plasma is the proportion of atoms that have lost or gained electrons, and is controlled mostly by the temperature. Even a partially ionized gas in which as little as 1% of the particles are ionized can have the characteristics of a plasma (i.e., response to magnetic fields and high electrical conductivity). The degree of ionization, ''α'' is defined as ''α'' = ''n''_i/(''n''_i + ''n''_a) where ''n''_i is the number density of ions and ''n''_a is the number density of neutral atoms. The ''electron density'' is related to this by the average charge state <Z> of the ions through ''n''_e = <Z> ''n''_i where ''n''_e is the number density of electrons. "Plasma is the fourth state of matter, consisting of electrons, ions and neutral atoms, usually at temperatures above 10⁴ degrees Kelvin."<ref name=Birdsall>{{ cite book |author=CK Birdsall, A. Bruce Langdon |title=Plasma Physics via Computer Simulation |publisher=CRC Press |location=New York |date=1 October 2004 |editor= |pages=479 |url=http://books.google.com/books?hl=en&lr=&id=S2lqgDTm6a4C&oi=fnd&pg=PR13&ots=nOPXyqtDo8&sig=-kA8YfaX6nlfFnaW3CYkATh-QPg |arxiv= |bibcode= |doi= |pmid= |isbn=9780750310253 |accessdate=2011-12-17 }}</ref> "The sun and stars are plasmas; the earth's ionosphere, Van Allen belts, magnetosphere, etc., are all plasmas. Indeed, plasma makes up much of the known matter in the universe."<ref name=Birdsall/> ==Plasma rains== "Hot plasma in the corona cooled and condensed along strong magnetic fields in the region" slowly falling back to the solar surface as plasma "rain".<ref name=WallRain/> {{clear}} ==Prominences== [[Image:Sunflare skylab4 big.jpg|thumb|right|250px|A major eruptive prominence is imaged by Skylab in 1973. Credit: [http://www.ksc.nasa.gov/history/skylab/skylab.html Skylab], NASA.{{tlx|free media}}]] [[Image:Detached sola prominence.jpg|thumb|right|250px|This shows a detached Solar prominence. Credit: [https://sites.google.com/site/thebrockeninglory/ Brocken Inaglory].{{tlx|free media}}]] A '''prominence''' is a large, bright feature extending outward from [a star's] surface, often in a [[w:Coronal loops|loop]] shape. Prominences are anchored to [a star's] surface in the [[w:photosphere|photosphere]], and extend outwards into the [star's] [[Coronal cloud|corona]]. While the corona consists of extremely hot ionized gases, known as [[w:Plasma (physics)|plasma]], which [does] not emit much visible light, prominences contain much cooler plasma, similar in composition to that of the [[w:chromosphere|chromosphere]]. A prominence forms over timescales of about a day, and stable prominences may persist in the corona for several months. Some prominences break apart and give rise to [[w:coronal mass ejection|coronal mass ejection]]s. A typical prominence extends over many thousands of kilometers; the largest on record was estimated at over 800,000 kilometres (500,000 mi) long<ref name="univtoday">{{ cite book |url=http://www.universetoday.com/96649/huge-solar-filament-stretches-across-the-sun/ |title=Huge Solar Filament Stretches Across the Sun |author=Nancy Atkinson |work=Universe Today |date=August 6, 2012 |accessdate=August 11, 2012 }}</ref> – roughly the radius of the Sun. "When a prominence is viewed from a different perspective so that it is against the [star] instead of against space, it appears darker than the surrounding background. This formation is instead called a [stellar] filament.<ref name="univtoday" /> It is possible for a projection to be both a filament and a prominence. Some prominences are so powerful that they throw out matter from the [star] into space at speeds ranging from 600&nbsp;km/s to more than 1000&nbsp;km/s. Other prominences form huge loops or arching columns of glowing gases over [starspots] that can reach heights of hundreds of thousands of kilometres. Prominences may last for a few days or even for a few months.<ref>{{ cite book | url=http://solar.physics.montana.edu/ypop/Program/hfilament.html | title=About Filaments and Prominences | accessdate=2010-01-02 }}</ref> Flocculi (plural of flocculus) is another term for these filaments, and dark flocculi typically describes the appearance of [stellar] prominences when viewed against the [stellar] disk in certain wavelengths. {{clear}} ==Regions== {{main|Regions/Astronomy}} [[Image:LASCO C1 coronagraph of solar corona.png‎|right|thumb|250px|A picture of the solar corona is taken with the [[w:LASCO|LASCO]] C1 coronagraph. The image is color coded for the doppler shift of the FeXIV 530.8 nm line. Credit: NASA and NRL.{{tlx|fairuse}}]] The preflare solar material is observed "to be an elevated cloud of prominence-like material which is suddenly lit up by the onslaught of hard electrons accelerated in the flare; the acceleration may be inside or outside the cloud, and brightening is seen in other areas of the solar surface on the same magnetic field lines."<ref name=Zirin78>{{ cite journal |author=Harold Zirin |title=The L-alpha/H-alpha ratio in solar flares, quasars, and the chromosphere |journal=Astrophysical Journal |month=June |year=1978 |volume=222 |issue=6 |pages=L105-7 |url= |bibcode=1978ApJ...222L.105Z |doi= 10.1086/182702 |pmid= |accessdate=2011-08-01 }}</ref> "A hot coronal cloud at ''T'' ~ 10⁷ K is left behind, presumably evaporated from the original material."<ref name=Zirin78/> "[O]nce ionized, the gas is rapidly heated by Coulomb collisions to the coronal cloud temperature, but as this material peels off, a cooler hydrogen-emitting region is left."<ref name=Zirin78/> Regions which are not in [[w:coronal hole|coronal hole]]s are "called 'coronal cloud' regions after their appearance in photographs of the Sun taken in soft X-rays, which most dramatically show up coronal holes."<ref name=McWhirter>{{ cite journal |author=McWhirter R. W. P. |author2=Kopp R. A. |title=The energy balance in the solar atmosphere above coronal holes |journal=Royal Astronomical Society, Monthly Notices |month=September |year=1979 |volume=188 |issue=9 |pages=871-81 |url= |bibcode=1979MNRAS.188..871M |doi= |pmid= |accessdate=2011-08-01 }}</ref> These 'coronal cloud' regions are "in fact the majority of the solar surface."<ref name=McWhirter/> Lying at a level above the 10⁴ K isotherm, "the thermally conducted flux is negligible, and bounded by the magnetic surfaces between open field (coronal hole) and closed field (coronal cloud) regions."<ref name=McWhirter/> "[C]oronal cloud regions produce no solar wind," but "[s]ome of the input energy may pass out of the cloud regions into the region where the wind is accelerated, thereby contributing to this process."<ref name=McWhirter/> In the image at right the iron (Fe XIV) green line is followed by doppler imaging to show associated relative coronal plasma velocity towards (-7 km/s side) and away from (+7 km/s side) the large angle spectrometric coronagraph [[w:LASCO|LASCO]] satellite camera. {{clear}} ==Starquakes== [[Image:MoretonWaveAnimation200612.gif|thumb|right|250px|This is an animation of a Moreton wave which occurred on the Sun at December 6, 2006. Credit: National Solar Observatory (NSO)/AURA/NSF and USAF Research Laboratory.{{tlx|fairuse}}]] [[Image:Solar tsunami.jpg|thumb|250px|left|This image shows a solar tsunami on May 19, 2007. Credit: NASA/STEREO/EUVI consortium.{{tlx|fairuse}}]] "The phenomenon of flare induced sunquakes - waves in the photosphere - discovered by Kosovichev and Zharkova (1998) and now widely studied (e.g. Kosovichev 2006) should also result from the momentum impulse delivered by a cometary impact."<ref name=Brown>{{ cite journal |author=J.C. Brown |author2=H.E. Potts |author3=L.J. Porter |author4=G.le Chat |title=Mass Loss, Destruction and Detection of Sun-grazing & -impacting Cometary Nuclei |journal=Astronomy & Astrophysics |date=November 8, 2011 |volume=535 |issue= |pages=12 |url=http://www.aanda.org/articles/aa/abs/2011/11/aa15660-10/aa15660-10.html |arxiv= |bibcode= |doi=10.1051/0004-6361/201015660 |pmid= |pdf=http://arxiv.org/pdf/1107.1857.pdf |accessdate=2012-11-25 }}</ref> A '''Moreton wave''' is the [[w:chromosphere|chromospheric]] signature of a large-scale solar [[Coronal cloud|coronal]] [[w:shock wave|shock wave]]. Described as a kind of [[Stars/Sun|solar]] '[[w:tsunami|tsunami]]',<ref name="tphill09">{{ cite book |author=Tony Phillips |title=Monster Waves on the Sun are Real |url=http://science.nasa.gov/science-news/science-at-nasa/2009/24nov_solartsunami/ |publisher=NASA |accessdate=16 July 2010 |date=November 24, 2009 }}</ref> they are generated by solar flares<ref name=Moreton>{{ cite journal |author=G. E. Moreton |title=Hα Observations of Flare-Initiated Disturbances with Velocities ~1000 km/sec |journal=Astronomical Journal |volume=65 |issue= |pages=494 |year=1960 |doi=10.1086/108346 |bibcode=1960AJ.....65U.494M }}</ref><ref name=Moreton60>{{ cite journal |author=G. E. Moreton, H. E. Ramsey |title=Recent Observations of Dynamical Phenomena Associated with Solar Flares |journal=Publications of the Astronomical Society of the Pacific |volume=72 |issue=428 |pages=357 |year=1960 |doi=10.1086/127549 |bibcode=1960PASP...72..357M }}</ref><ref name=Athay61>{{ cite journal |author=R. Grant Athay, Gail E. Moreton |title=Impulsive Phenomena of the Solar Atmosphere. I. Some Optical Events Associated with Flares Showing Explosive Phase |journal=The Astrophysical Journal |year=1961 |volume=133 |issue= |pages=935 |doi=10.1086/147098 |bibcode=1961ApJ...133..935A }}</ref>. The 1995 launch of the [[w:Solar and Heliospheric Observatory|Solar and Heliospheric Observatory]] led to observation of coronal waves, which cause Moreton waves. (SOHO's [[w:Extreme ultraviolet Imaging Telescope|EIT]] instrument discovered another, different wave type called 'EIT waves'.)<ref name=Chen>{{ cite journal |url=http://solar.physics.montana.edu/nuggets/2002/020208/020208.html |title=Moreton waves and coronal waves |journal=The Astrophysical Journal |volume=572 |issue= |pages=L99–L102 |year=2002 |bibcode = 2002ApJ...572L..99C |doi = 10.1086/341486 |author=P. F. Chen |author2=S. T. Wu |author3=K. Shibata |author4=C. Fang }}</ref> The reality of Moreton waves (aka fast-mode [[w:Magnetohydrodynamics|MHD]] waves) has also been confirmed by the two [[w:STEREO|STEREO]] spacecraft. They observed a 100,000-km-high wave of hot plasma and magnetism, moving at 250&nbsp;km/second, in conjunction with a big coronal mass ejection in February 2009.<ref name=Atkins>{{ cite book |author=William Atkins |title=STEREO spacecraft finds gigantic tsunami on Sun |url=http://www.itwire.com/science-news/space/29658-stereo-spacecraft-finds-gigantic-tsunami-on-sun |publisher=iTWire |accessdate=16 July 2010 |date=26 November 2009 }}</ref><ref name="pho111909">{{ cite book |title=Mystery of the Solar Tsunami -- Solved |url=http://www.physorg.com/news177872248.html |publisher=PhysOrg.com |accessdate=16 July 2010 |author=JPL/NASA |date=November 19, 2009 }}</ref> Moreton waves propagate at a speed of usually 500–1500&nbsp;km/s. [[w:Yutaka Uchida|Yutaka Uchida]] interpreted Moreton waves as MHD fast mode shock waves propagating in the corona.<ref name=Sakurai2002>{{ cite book |author=Takashi Sakurai |title=SolarNews Newsletter |url=http://spd.aas.org/SolarNews/archive/news.2002/19.sep |publisher=Solar Physics Division, American Astronomical Society |accessdate=15 June 2011 |date=3 September 2002 }}</ref> He links them to [[w:type II radio bursts|type II radio bursts]], which are radio wave discharges created when coronal mass ejections accelerate shocks.<ref name=Layton>{{ cite book |author=Laura Layton |title=STEREO Spies First Major Activity of Solar Cycle 24 |url=http://www.nasa.gov/mission_pages/stereo/news/solarcycle24.html |publisher=NASA |accessdate=15 June 2011 |date=May 15, 2009 }}</ref> Moreton waves can be observed primarily in the [[w:Hα|Hα]] band.<ref name="Narukage, et al.">{{ cite journal |author=N. Narukage |author2=Shigeru |author3=Miwako Kadota |author4=Reizaburo Kitai |author5=Hiroki Kurokawa |author6=Kazunari Shibata |year=2004 |title=Moreton waves observed at Hida Observatory |journal = Proceedings IAU Symposium |issue = 223 |pages = 367–370 |doi=10.1017/S1743921304006143 |url=http://journals.cambridge.org/production/action/cjoGetFulltext?fulltextid=288483 |accessdate = 2006-12-11 |volume = 2004 }}</ref> {{clear}} ==Stellar cycles== [[Image:Sunspot_butterfly_graph.gif|thumb|200px|right|The butterfly diagram shows paired sunspot pattern. The graph is of sunspot Wolf number versus time. Credit: NASA, Marshal Space Flight Center, Solar Physics.{{tlx|free media}}]] The solar cycle has a great influence on [[w:space weather|space weather]], and a significant influence on the Earth's climate since the Sun's luminosity has a direct relationship with magnetic activity.<ref name=Wilson>{{ cite journal |author=R. C. Willson, H. S. Hudson |year=1991 |title=The Sun's luminosity over a complete solar cycle |journal=Nature |volume=351 |issue=6321 |pages=42–4 |doi=10.1038/351042a0 |bibcode = 1991Natur.351...42W }}</ref> Solar activity minima tend to be correlated with colder temperatures, and longer than average solar cycles tend to be correlated with hotter temperatures. In the 17th century, the solar cycle appeared to have stopped entirely for several decades; few sunspots were observed during this period. During this era, known as the [[w:Maunder minimum|Maunder minimum]] or [[w:Little Ice Age|Little Ice Age]], Europe experienced unusually cold temperatures.<ref name="Lean">{{ cite journal |last=Lean |first=J. |last2=Skumanich |first2=A. |last3=White |first3=O. |year=1992 |title=Estimating the Sun's radiative output during the Maunder Minimum |journal=Geophysical Research Letters |volume=19 |issue=15 |pages=1591–1594 |doi=10.1029/92GL01578 |ref=harv |bibcode=1992GeoRL..19.1591L }}</ref> Earlier extended minima have been discovered through analysis of [[w:tree ring|tree ring]]s and appear to have coincided with lower-than-average global temperatures.<ref name=Mackay>{{ cite book |author=R. M. Mackay, M. A. K. Khalil |title=Greenhouse gases and global warming, In: ''Trace Gas Emissions and Plants'' |url= http://books.google.com/?id=tQBS3bAX8fUC&pg=PA1 |editor=S. N. Singh |year=2000 |pages=1–28 |publisher=Springer |isbn=978-0-7923-6545-7 }}</ref> "MOST current literature on solar activity assumes that the planets do not affect it, and that conditions internal to the Sun are primarily responsible for the solar cycle. Bigg¹, however, has shown that the period of Mercury's orbit appears in the sunspot data, and that the influence of Mercury depends on the phases of Venus, Earth, and Jupiter."<ref name=Wood>{{ cite journal |author=K. D. Wood |title=Physical Sciences: Sunspots and Planets |journal=Nature |month=November 10, |year=1972 |volume=240 |issue=5376 |pages=91-3 |url=http://www.nature.com/nature/journal/v240/n5376/abs/240091a0.html |arxiv= |bibcode=1972Natur.240...91W |doi=10.1038/240091a0 |pmid= |accessdate=2013-07-07 }}</ref> "It is shown that starting with the alignment of Venus with Jupiter at perihelion position, these two planets will perfectly align at Jupiter's perihelion after every 23.7 years".<ref name=Verma>{{ cite book |author=S.D. Verma |title=Influence of Planetary Motion and Radial Alignment of Planets on Sun, In: ''Space Dynamics and Celestial Mechanics'' |publisher=Springer Netherlands |location= |year=1986 |editor=K. B. Bhatnagar |volume=127 |issue= |pages=143-54 |url=http://link.springer.com/chapter/10.1007/978-94-009-4732-0_13 |arxiv= |bibcode= |doi=10.1007/978-94-009-4732-0_13 |pmid= |isbn=978-94-010-8603-5 |accessdate=2013-07-07 }}</ref> "The tidal forces hypothesis for solar cycles has been proposed by Wood (1972) and others. Table 2 below shows the relative tidal forces of the planets on the sun. Jupiter, Venus, Earth and Mercury are called the "tidal planets" because they are the most significant. According to Wood, the especially good alignments of J-V-E with the sun which occur about every 11 years are the cause of the sunspot cycle. He has shown that the sunspot cycle is synchronous with the alignments, and J. Schove's data for 1500 year of sunspot maxima supports the 11.07 year J-V-E period average."<ref name=Tomes/> "Both the 11.86 year Jupiter tropical period (time between perihelion's or closest approaches to the sun and the 9.93 year J-S alignment periods are found in sunspot spectral analysis. Unfortunately direct calculations of the tidal forces of all planets does not support the occurrence of the dominant 11.07 year cycle. Instead, the 11.86 year period of Jupiter's perihelion dominates the results. This has caused problems for several researchers in this field."<ref name=Tomes>{{ cite journal |author=Ray Tomes |title=Towards a Unified Theory of Cycles |publisher=Cycles Research Institute |location= |month=February |year=1990 |editor= |volume= |issue= |pages=21 |url=http://cyclesresearchinstitute.org/cycles-general/tomes_unified_cycles.pdf |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2013-07-07 }}</ref> "[B]y assuming a harmonic variation having a period of 11.13 years ... the phases of such a variation [in polar diameter minus equatorial diameter of the Sun] coincide to within one-fifth of a year with the phases of the sun-spot fluctuations; that, at times corresponding to minimum of sun-spottedness, the polar diameter is relatively larger; that, at times of maximum sun-spottedness, the equatorial diameter is relatively larger. The amplitude of the variation is extremely small, but its reality would seem to be established. [This] at least renders the existence of such periodic fluctuations in the shape of the sun more probable than their non-existence."<ref name=Poor>{{ cite journal |author=Charles Lane Poor |title=An investigation of the figure of the Sun and of possible variations in its size and shape [Reprint of: Annals N.Y. Acad Sci., Vol XVIII, pp.385 - 424] |journal=Contributions from the Rutherford Observatory of Columbia University New York |month=August |year=1908 |volume=26 |issue=08 |pages=385-424 |url= |arxiv= |bibcode=1908CoRut..26..385P |doi= |pmid= |accessdate=2013-05-16 }}</ref> "Solar oblateness, the difference between the equatorial and polar diameters, reflects certain fundamental properties of the Sun. ... the oblateness reflects properties of the Sun's interior, ... [There is] a time varying, excess equatorial brightness [producing] a difference between the equatorial and polar limb darkening functions ... at times when the excess brightness is reduced, the intrinsic visual oblateness can be obtained from the observations without detailed knowledge of the excess brightness. A period of reduced excess brightness occurred in 1973 September."<ref name=Hill>{{ cite journal |author=H. A. Hill |author2=R. T. Stebbins |title=The intrinsic visual oblateness of the sun |journal=The Astrophysical Journal |month=September 1, |year=1975 |volume=200 |issue=09 |pages=471-5 |url= |arxiv= |bibcode=1975ApJ...200..471H |doi=10.1086/153813 |pmid= |accessdate=2013-05-16 }}</ref> The period of reduced excess equatorial brightness occurred between solar cycle maximum around 1970 and minimum around 1975. Considering excess equatorial brightness and seeking to perform measurements at opportunities of reduced excess equatorial brightness has the effect of reducing solar oblateness from some 86.6 ± 6.6 milli-arcsec to 18.4 ± 12.5 milli-arcsec.<ref name=Hill/> The Babcock Model describes a mechanism which can explain magnetic and sunspot patterns observed on the Sun: # The start of the 22-year cycle begins with a well-established dipole field component aligned along the solar rotational axis. The field lines tend to be held by the highly conductive solar plasma of the solar surface. # The solar surface plasma rotation rate is different at different latitudes, and the rotation rate is 20 percent faster at the equator than at the poles (one rotation every 27 days). Consequently, the magnetic field lines are wrapped by 20 percent every 27 days. # After many rotations, the field lines become highly twisted and bundled, increasing their intensity, and the resulting buoyancy lifts the bundle to the solar surface, forming a bipolar field that appears as two spots, being kinks in the field lines. # The sunspots result from the strong local magnetic fields in the solar surface that exclude the light-emitting solar plasma and appear as darkened spots on the solar surface. # The leading spot of the bipolar field has the same polarity as the solar hemisphere, and the trailing spot is of opposite polarity. The leading spot of the bipolar field tends to migrate towards the equator, while the trailing spot of opposite polarity migrates towards the solar pole of the respective hemisphere with a resultant reduction of the solar dipole moment. This process of sunspot formation and migration continues until the solar dipole field reverses (after about 11 years). # The solar dipole field, through similar processes, reverses again at the end of the 22-year cycle. # The magnetic field of the spot at the equator sometimes weakens, allowing an influx of coronal plasma that increases the internal pressure and forms a magnetic bubble which may burst and produce an ejection of coronal mass, leaving a coronal hole with open field lines. Such a coronal mass ejections are a source of the high-speed solar wind. # The fluctuations in the bundled fields convert magnetic field energy into plasma heating, producing emission of electromagnetic radiation as intense ultraviolet (UV) and X-rays. {{clear}} ==Stellar winds== [[Image:SpaceEnvironmentOverview From 19830101.jpg|thumb|right|200px|This image shows an overview of the space weather conditions over several solar cycles including the relationship between sunspot numbers and cosmic rays. Credit: [[c:User:Daniel Wilkinson|Daniel Wilkinson]].{{tlx|free media}}]] "The '''solar wind''' is a stream of charged particles ejected from the upper atmosphere of the [[Sun (star)|Sun]]. It mostly consists of electrons and protons with energies usually between 1.5 and 10 [[w:electronvolt|keV]]. Δ''T''_''A'' may have values from "7-19 min for a small sample of well-connected ... cosmic-ray flares."<ref name="Cliver"/> The transit time anomaly may be explained by a rise time associated with the ground-level events (GLEs). "The average GLE rise time ... for well-connected ... events ... defined to be the time from event onset to maximum as measured by the neutron monitor station showing the largest increase and whose asymptotic cone of acceptance ... includes the nominal direction of the Archimedean spiral path, is 21.3 min."<ref name="Cliver"/> The solar wind originates through the polar coronal holes. "The solar wind is a plasma, composed primarily of electrons and lone protons, and the variations in the index of refraction are caused by variations in the density of the plasma.<ref>Jokipii (1973), pp. 11–12.</ref> Different indices of refraction result in phase changes between waves traveling through different locations, which results in interference. As the waves interfere, both the frequency of the wave and its angular size are broadened, and the intensity varies.<ref>Alurkar (1997), p. 11.</ref>"<ref name=McBride>{{ cite web |author=[[w:User:James McBride|James McBride]] |title=Interplanetary scintillation |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=October 1, 2013 |url=https://en.wikipedia.org/wiki/Interplanetary_scintillation |accessdate=2014-01-23 }}</ref> ==Van Allen radiation belts== The '''Van Allen radiation belt''' is split into two distinct belts, with energetic electrons forming the outer belt and a combination of protons and electrons forming the inner belts. In addition, the radiation belts contain lesser amounts of other nuclei, such as [[w:alpha particle|alpha particle]]s. The trapped particle population of the outer belt is varied, containing electrons and various ions. Most of the ions are in the form of energetic protons, but a certain percentage are [[w:alpha particles|alpha particles]] and O⁺ oxygen ions, similar to those in the [[w:ionosphere|ionosphere]] but much more energetic. While protons form one radiation belt, trapped electrons present two distinct structures, the inner and outer belt. The inner electron Van Allen Belt extends typically from an altitude of 1.2 to 3 Earth radii (L values of 1 to 3).<ref name=Ganushkina>{{ cite journal | author=Ganushkina N.Y. |author2=I. Dandouras |author3=Y. Y. Shprits |author4=J. Cao | title=Locations of boundaries of outer and inner radiation belts as observed by Cluster and Double Star | journal=Journal of Geophysical Research | volume=116 |issue=A09234 |doi=10.1029/2010JA016376 | year=2011 | pages=1–18 |url=http://onlinelibrary.wiley.com/doi/10.1029/2010JA016376/abstract }}</ref> In certain cases when solar activity is stronger or in geographical areas such as the [[w:South Atlantic Anomaly|South Atlantic Anomaly]] (SAA), the inner boundary may go down to roughly 200 kilometers<ref>{{ cite book |title=ECSS Space engineering |date=15 November 2008 |url=https://www.scribd.com/document/122967505/ECSS-space-engineering }}</ref> above the Earth's surface. The inner belt contains high concentrations of electrons in the range of hundreds of keV and energetic protons with energies exceeding 100 MeV, trapped by the strong (relative to the outer belts) magnetic fields in the region.<ref name=Gusev>{{ cite journal | author=Gusev A.A. |author2=G.I. Pugacheva |author3=U.B. Jayanthi |author4=N. Schuch | title=Modeling of Low-altitude Quasi-trapped Proton Fluxes at the Equatorial Inner Magnetosphere | journal=Brazilian Journal of Physics | vol. 33 | no. 4 | year=2003 | pages=775–781 |url=http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-97332003000400029 }}</ref> It is believed that proton energies exceeding 50 MeV in the lower belts at lower altitudes are the result of the [[w:beta decay|beta decay]] of [[w:neutrons|neutrons]] created by cosmic ray collisions with nuclei of the upper atmosphere. The source of lower energy protons is believed to be proton diffusion due to changes in the magnetic field during geomagnetic storms.<ref name=Tascione>{{ cite book | first=Thomas F. | last=Tascione | title=Introduction to the Space Environment, 2nd. Ed. | publisher=Kreiger Publishing CO.| location=Malabar, Florida USA | year=1994 |url=http://astrobooks.com/introductiontothespaceenvironmentsecondeditionsoftbackthomasftascione-1994.aspx | isbn=0-89464-044-5}}</ref> Due to the slight offset of the belts from Earth's geometric center, the inner Van Allen belt makes its closest approach to the surface at the South Atlantic Anomaly.<ref name="Goddard">NASA Goddard Spaceflight Center, |url=http://image.gsfc.nasa.gov/poetry/tour/AAvan.html |title=The Van Allen Belts] (Accessed May 25, 2011)</ref><ref name=Underwood>{{ cite journal | author=Underwood, C. |author2=Brock, D. |author3=Williams, P. |author4=Kim, S. |author5=Dilão, R. |author6=Ribeiro Santos, P. |author7=Brito, M. |author8=Dyer, C. |author9=Sims, A. | title=Radiation Environment Measurements with the Cosmic Ray Experiments On-Board the KITSAT-1 and PoSAT-1 Micro-Satellites | journal=IEEE Transactions on Nuclear Sciences | volume=41 | year=1994 | pages=2353–2360 |url=http://ieeexplore.ieee.org/document/340587/ }}</ref> The proton belts contain [[w:protons|protons]] with kinetic energies ranging from about 100 keV (which can penetrate 0.6&nbsp;microns of lead) to over 400 MeV (which can penetrate 143&nbsp;mm of lead).<ref name=Hess>{{cite book |author=Wilmot N. Hess |title=The Radiation Belt and Magnetosphere |publisher=Blaisdell Pub. Co. |date=1968 |url=http://adsabs.harvard.edu/abs/1968rbm..book.....H }}</ref> The [[w:Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics|PAMELA]] experiment detected orders of magnitude higher levels of [[w:antiproton|antiproton]]s than are expected from normal [[w:particle decay|particle decay]]s while passing through the SAA. This suggests the van Allen belts confine a significant flux of antiprotons produced by the interaction of the Earth's upper atmosphere with [[w:cosmic rays|cosmic rays]].<ref name=Adriani>{{ cite journal | doi = 10.1088/2041-8205/737/2/L29 | title = The Discovery of Geomagnetically Trapped Cosmic-Ray Antiprotons | year = 2011 | last1 = Adriani | first1 = O. | last2 = Barbarino | first2 = G. C. | last3 = Bazilevskaya | first3 = G. A. | last4 = Bellotti | first4 = R. | last5 = Boezio | first5 = M. | last6 = Bogomolov | first6 = E. A. | last7 = Bongi | first7 = M. | last8 = Bonvicini | first8 = V. | last9 = Borisov | first9 = S. | journal = The Astrophysical Journal Letters | volume = 737 | issue = 2 | pages = L29 | bibcode = 2011ApJ...737L..29A | arxiv=1107.4882v1 }}</ref> The energy of the antiprotons has been measured in the range from 60 - 750 MeV. When cosmic-ray protons enter the Earth’s atmosphere they collide with molecules, mainly oxygen and nitrogen, to produce a cascade of billions of lighter particles, a so-called air shower. An air shower is an extensive (many kilometres wide) cascade of ionized particles and electromagnetic radiation produced in the atmosphere when a primary cosmic-ray proton (i.e. one of extraterrestrial origin) enters the atmosphere. During solar proton events, ionization can reach unusually high levels in the D-region over high and polar latitudes. Such very rare events are known as Polar Cap Absorption (or PCA) events, because the increased ionization significantly enhances the absorption of radio signals passing through the region. In fact, absorption levels can increase by many tens of dB during intense events, which is enough to absorb most (if not all) transpolar HF radio signal transmissions. Such events typically last less than 24 to 48 hours. Associated with solar flares is a release of high-energy protons. These particles can hit the Earth within 15 minutes to 2 hours of the solar flare. The protons spiral around and down the magnetic field lines of the Earth and penetrate into the atmosphere near the magnetic poles increasing the ionization of the D and E layers. PCA's typically last anywhere from about an hour to several days, with an average of around 24 to 36 hours. ==Cosmic rays== {{main|Radiation/Cosmic rays}} "A persistent problem of solar cosmic-ray research has been the lack of observations bearing on the timing and conditions in which protons that escape to the interplanetary medium are first accelerated in the corona."<ref name="Cliver">{{cite journal |author=E. W. Cliver |author2=S. W. Kahler |author3=M. A. Shea |author4=D. F. Smart |title=Injection onsets of ~2 GeV protons, ~1 MeV electrons, and ~100 keV electrons in solar cosmic ray flares |journal=The Astrophysical Journal |month=September 1 |year=1982 |volume=260 |issue=9 |pages=362-70 |url= |arxiv= |bibcode=1982ApJ...260..362C |doi= |pmid= |accessdate=2012-08-21 }}</ref> "For solar cosmic-rays, the apparent lack of proton acceleration in the corona seems justified, in contrast to the electrons, proton bremsstrahlung and gyrosynchrotron emission are negligible. This suggests a transit time anomaly, Δ''T''_''A'', defined as follows: : Δ''T''_''A'' = Δ''T''_onset - 11 min, where Δ''T''_onset is the deduced Sun-Earth transit time for the first arriving relativistic protons and 11 min is the nominal transit time for a ~2 GeV proton traversing a 1.3 AU Archimedes spiral path."<ref name="Cliver">{{cite journal |author=E. W. Cliver |author2=S. W. Kahler |author3=M. A. Shea |author4=D. F. Smart |title=Injection onsets of ~2 GeV protons, ~1 MeV electrons, and ~100 keV electrons in solar cosmic ray flares |journal=The Astrophysical Journal |month=September 1 |year=1982 |volume=260 |issue=9 |pages=362-70 |url= |arxiv= |bibcode=1982ApJ...260..362C |doi= |pmid= |accessdate=2012-08-21 }}</ref> ==Protons== {{main|Radiation astronomy/Protons|Proton astronomy}} [[Image:GOES protons.jpg|thumb|right|250px|This graph displays the flux of high energy protons measured by GOES 11 over four days from November 2, 2004, to November 4, 2003. Credit: NOAA.{{tlx|free media}}]] The Sun and the solar wind, at least that portion that originates through the polar coronal holes apparently from the photosphere, may be major sources of protons within the solar system. At right is a temporal distribution of solar proton flux in units of particles cm^-2 s^-1 sr^-1 as measured by GOES 11 over the four days from November 2, 2003, to November 4, 2003, in three windows of energy: ≥ 100 MeV (green), ≥ 50 MeV (blue), and ≥ 10 MeV (red). The percentage originating from the surface of the Sun either directly or through the contribution to the solar wind is not indicated. {{clear}} ==Electrons== {{main|Radiation astronomy/Electrons}} "The density of the coronal cloud deduced in this case is about 2 x 10¹¹ electrons per cubic centimeter."<ref name=Zinn1965>{{ cite book |author=H. Zinn |title=Solar Flares and Concurrent Phenomena in the Solar Atmosphere, In: ''Proceedings of the Plasma Space Science Symposium'' |publisher=Springer |location=Netherlands |year=1965 |editor=C. C. Chang |editor2=S. S. Huang |volume=3 |issue= |pages=38-51 |url=http://link.springer.com/chapter/10.1007/978-94-011-7542-5_5 |arxiv= |bibcode= |doi=10.1007/978-94-011-7542-5_5 |pmid= |isbn=978-94-011-7544-9 |accessdate=2013-07-07 }}</ref> ==Positrons== {{main|Radiation astronomy/Positrons}} [[Image:Rhessi0269 web.jpg|thumb|right|250px|RHESSI observes high-energy phenomena from a solar flare. Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio.{{tlx|free media}}]] The solar flare at Active Region 10039 on July 23, 2002, exhibits many exceptional high-energy phenomena including the 2.223 MeV neutron capture line and the 511 keV electron-positron (antimatter) annihilation line. In the image at right, the RHESSI low-energy channels (12-25 keV) are represented in red and appear predominantly in coronal loops. The high-energy flux appears as blue at the footpoints of the coronal loops. Violet is used to indicate the location and relative intensity of the 2.2 MeV emission. During solar flares “[s]everal radioactive nuclei that emit positrons are also produced; [which] slow down and annihilate in flight with the emission of two 511 keV photons or form positronium with the emission of either a three gamma continuum (each photon < 511 keV) or two 511 keV photons."<ref name=Share>{{ cite book |author=Gerald H. Share |author2=Ronald J. Murphy |title=Solar Gamma-Ray Line Spectroscopy – Physics of a Flaring Star, In: ''Stars as Suns: Activity, Evolution and Planets'' |publisher=Astronomical Society of the Pacific |location=San Francisco, CA |date=January 2004 |editor=Andrea K. Dupree, A. O. Benz |pages=133-44 |url=http://heseweb.nrl.navy.mil/gamma/solar/papers/share_iau_04.pdf |arxiv= |bibcode=2004IAUS..219..133S |doi= |pmid= |isbn=158381163X |accessdate=2012-03-15 }}</ref> The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) made the first high-resolution observation of the solar positron-electron annihilation line during the July 23, 2003 solar flare.<ref name=Share/> The observations are somewhat consistent with electron-positron annihilation in a quiet solar atmosphere via positronium as well as during flares.<ref name=Share/> Line-broadening is due to "the velocity of the positronium."<ref name=Share/> "The width of the annihilation line is also consistent ... with thermal broadening (Gaussian width of 8.1 ± 1.1 keV) in a plasma at 4-7 x 10⁵ K. ... The ''RHESSI'' and all but two of the ''SMM'' measurements are consistent with densities ≤ 10¹² H cm^-3 [but] <10% of the p and α interactions producing positrons occur at these low densities. ... positrons produced by ³He interactions form higher in the solar atmosphere ... all observations are consistent with densities > 10¹² H cm^-3. But such densities require formation of a substantial mass of atmosphere at transition region temperatures."<ref name=Share/> {{clear}} ==Neutrinos== {{main|Radiation astronomy/Neutrinos|Neutrino astronomy}} [[Image:Neusun1 superk1.jpg|thumb|right|250px|This "neutrino image" of the Sun is produced by using the Super-Kamiokande to detect the neutrinos from nuclear fusion coming from the Sun. Credit: R. Svoboda and K. Gordan (LSU).{{tlx|fairuse}}]] [[Image:Bahcall Figure 2.jpg|thumb|right|250px|This figure shows a detected 94 % correlation between scaled sunspot numbers and neutrino detections. Credit: John N. Bahcall.{{tlx|fairuse}}]] Neutrinos are hard to detect. The Super-Kamiokande, or "Super-K" is a large-scale experiment constructed in an unused mine in Japan to detect and study neutrinos. The image at right required 500 days worth of data to produce the "neutrino image" of the Sun. The image is centered on the Sun's calculated position. It covers a 90° x 90° octant of the sky (in right ascension and declination). The higher the brightness of the color, the larger is the neutrino flux. The surface of the Sun is not a known source of neutrinos. Those detected may be from nucleosynthesis within the coronal cloud in the near vicinity of the Sun or perhaps from nucleosynthesis occurring interior to the Sun. "[N]eutrino flux increases noted in Homestake results [coincide] with major solar flares [14]."<ref name=Dubin>{{ cite journal |author=Maurice Dubin |author2=Robert K. Soberman |title=Resolution of the Solar Neutrino Anomaly |journal=arXiv |date=April 1996 |volume= |issue= |pages=1-8 |url=http://arxiv.org/abs/astro-ph/9604074 |arxiv=astro-ph/9604074 |bibcode=1996astro.ph..4074D |doi= |pmid= |pdf=http://arxiv.org/pdf/astro-ph/9604074.pdf |accessdate=2012-11-11 }}</ref> This result together with those in the next two paragraphs establishes that neutrinos are being produced by processes above the photosphere and probably within 2-4 solar radii as most solar flares give off energy close to and into the chromosphere. "The correlation between a great solar flare and Homestake neutrino enhancement was tested in 1991. Six major flares occurred from May 25 to June 15 including the great June 4 flare associated with a coronal mass ejection and production of the strongest interplanetary shock wave ever recorded (later detected from spacecraft at 34, 35, 48, and 53 AU) [15]. It also caused the largest and most persistent (several months) signal ever detected by terrestrial cosmic ray neutron monitors in 30 years of operation [16]. The Homestake exposure (June 1–7) measured a mean ³⁷Ar production rate of 3.2 ± 1.5 atoms/day (≈19 ³⁷Ar atoms produced in 6 days) [13]; about 5 times the rate of ≈ 0.65 day ⁻¹ for the preceding and following runs, > 6 times the long term mean of ≈ 0.5 day⁻¹ and > 2 1/2 times the highest rates recorded in ∼ 25 operating years."<ref name=Dubin/> The highest flux of solar neutrinos come directly from the proton-proton interaction, and have a low energy, up to 400 keV. There are also several other significant production mechanisms, with energies up to 18 MeV.<ref name=Bellerive>A. Bellerive, [http://arxiv.org/abs/hep-ex/0312045 Review of solar neutrino experiments]. Int.J.Mod.Phys. A19 (2004) 1167-1179</ref> The parts of the Sun above the photosphere are referred to collectively as the ''solar atmosphere''.<ref name=Abhyankar1977>{{ cite journal |author=K.D. Abhyankar |title=A Survey of the Solar Atmospheric Models 1977 |journal=Bull. Astr. Soc. India |volume=5 |bibcode=1977BASI....5...40A |pages=40–44 |url=http://prints.iiap.res.in/handle/2248/510 }}</ref> "Neutrinos can be produced by energetic protons accelerated in solar magnetic fields. Such protons produce pions, and therefore muons, hence also neutrinos as a decay product, in the solar atmosphere."<ref name=Bahcall1987>{{ cite journal |author=J. N. Bahcall |author2=G. B. Field |author3=W. H. Press |title=Is solar neutrino capture rate correlated with sunspot number? |journal=The Astrophysical Journal |date=September 1, 1987 |volume=320 |issue=9 |pages=L69-73 |url=http://articles.adsabs.harvard.edu//full/1987ApJ...320L..69B/L000069.000.html |arxiv= |bibcode=1987ApJ...320L..69B |doi=10.1086/184978 |pmid= |accessdate=2013-07-07 }}</ref> "Energetic protons in the solar corona could explain Figure 2 [at right] only if (1) they tap a substantial fraction of the entire energy generated in the corona, (2) the energy generated in the corona is at least 3 times what has been deduced from the observations, (3) the vast majority of energetic protons do not escape the Sun, (4) the proton energy spectrum is unusually hard (''p''₀ = 300 MeV c^-1, and (5) the sign of the variation is opposite to what one would predict. As the likelihood of all of these conditions being fulfilled seems extremely small, we do not believe that neutrinos produced by energetic protons in the solar atmosphere contribute significantly to the neutrino capture in the ³⁷Cl experiment."<ref name=Bahcall1987/> "The total number of neutrinos of all types agrees with the number predicted by the computer model of the Sun. Electron neutrinos constitute about a third of the total number of neutrinos. [...] The missing neutrinos were actually present, but in the form of the more difficult to detect muon and tau neutrinos."<ref name=Bahcall2004>{{ cite book |author=John N. Bahcall |title=Solving the Mystery of the Missing Neutrinos |publisher=Nobel Media AB |location= |date=April 28, 2004 |url=http://www.nobelprize.org/nobel_prizes/themes/physics/bahcall/ |accessdate=2014-03-08 }}</ref> The reactions that produce the higher energy neutrinos: ν_µ and ν_τ are. For antiproton-proton annihilation at rest, a meson result is, for example, :<math>p^+ + \bar{p}^- \rightarrow \pi^+ + \pi^-,</math><ref name=Klempt>{{ cite journal |author=Eberhard Klempt |author2=Chris Batty |author3=Jean-Marc Richard |title=The antinucleon-nucleon interaction at low energy: annihilation dynamics |journal=Physics Reports |date=July 2005 |volume=413 |issue=4-5 |pages=197-317 |url=http://adsabs.harvard.edu/abs/2005PhR...413..197K |arxiv=hep-ex/0501020 |bibcode=2005PhR...413..197K |doi=10.1016/j.physrep.2005.03.002 |pmid= |accessdate=2014-03-09 }}</ref> :<math>{\pi}^+ \rightarrow {\mu}^+ + {\nu}_{\mu} \rightarrow e^+ + {\nu}_e + {\bar{\nu}}_{\mu} + {\nu}_{\mu},</math><ref name=Waxman>{{ cite journal |author=Eli Waxman |author2=John Bahcall |title=High energy neutrinos from astrophysical sources: An upper bound |journal=Physical Review D |date=December 14, 1998 |volume=59 |issue=2 |pages=e023002 |url=http://prd.aps.org/abstract/PRD/v59/i2/e023002 |arxiv=hep--ph/9807282 |bibcode= |doi=10.1103/PhysRevD.59.023002 |pmid= |accessdate=2014-03-09 }}</ref> and :<math>D_S \rightarrow \tau + \bar{\nu}_{\tau} \rightarrow \nu_{\tau} + \bar{\nu}_{\tau}.</math><ref name=Kodama>{{ cite journal |author=K. Kodama |author2=N. Ushida1 |author3=C. Andreopoulos |author4=N. Saoulidou |author5=G. Tzanakos |author6=P. Yager |author7=B. Baller |author8=D. Boehnlein |author9=W. Freeman |author10=B. Lundberg |author11=J. Morfin |author12=R. Rameika |author13=J.C. Yun |author14=J.S. Song |author15=C.S. Yoon |author16=S.H.Chung |author17=P. Berghaus |author18=M. Kubanstev |author19=N.W. Reay |author20=R. Sidwell |author21=N. Stanton |author22=S. Yoshida |author23=S. Aoki |author24=T. Hara |author25=J.T. Rhee |author26=D. Ciampa |author27=C. Erickson |author28=M. Graham |author29=K. Heller |author30=R. Rusack |author31=R. Schwienhorst |author32=J. Sielaff |author33=J. Trammell |author34=J. Wilcox |author35=K. Hoshino |author36=H. Jiko |author37=M. Miyanishi |author38=M. Komatsu |author39=M. Nakamura |author40=T. Nakano |author41=K. Niwa |author42=N. Nonaka |author43=K. Okada |author44=O. Sato |author45=T. Akdogan |author46=V. Paolone |author47=C. Rosenfeld |author48=A. Kulik |author49=T. Kafka |author50=W. Oliver |author51=T. Patzak |author52=J. Schneps |title=Observation of tau neutrino interactions |journal=Physics Letters B |date=April 12, 2001 |volume=504 |issue=3 |pages=218-24 |url=http://www.sciencedirect.com/science/article/pii/S0370269301003070 |arxiv= |bibcode= |doi= |pmid= |accessdate=2014-03-10 }}</ref> "All other sources of ν_τ are estimated to have contributed an additional 15%."<ref name=Kodama/> :<math>\tau \rightarrow e + \nu_{\tau} + \nu_e,</math><ref name=Kodama/> for two neutrinos.<ref name=Kodama/> :<math>\tau \rightarrow h + \nu_{\tau} + X,</math><ref name=Kodama/> where <math>h</math> is a hadron, for two neutrinos.<ref name=Kodama/> {{clear}} ==Gamma rays== {{main|Radiation astronomy/Gamma rays|Gamma-ray astronomy}} [[Image:Gamma sun1.jpg|thumb|right|250px|The Sun is seen in gamma rays by COMPTEL during a June 15, 1991, solar flare. Credit: COMPTEL team, University of New Hampshire.{{tlx|fairuse}}]] The surface of the Sun has yet to be detected as a gamma ray source, reflector, or in fluorescence. RHESSI was the first satellite to image solar gamma rays from a solar flare.<ref>[http://adsabs.harvard.edu/abs/2003ApJ...595L..77H] First Gamma-Ray Images of a Solar Flare (Hurford et al. 2003)</ref> {{clear}} ==X-rays== {{main|Radiation astronomy/X-rays|X-ray astronomy}} [[Image:X-ray image of the Pleiades.gif|thumb|right|250px|The image shows the Pleiades in X-rays, taken by ROSAT, where the brightest optical stars are inside the green squares. Credit: [[w:User:Worldtraveller|Worldtraveller]].{{tlx|free media}}]] "The Pleiades star cluster is one of the jewels of the northern sky. To the unaided eye it appears as an alluring group of stars in the constellation Taurus, while telescopic views reveal cluster stars surrounded by delicate blue wisps of dust-reflected starlight. To the X-ray telescopes on board the orbiting ROSAT observatory, the cluster also presents an impressive, but slightly altered, appearance. This false color image [at right] was produced from ROSAT observations by translating different X-ray energy bands to visual colors - the lowest energies are shown in red, medium in green, and highest energies in blue. (The green boxes mark the position of the seven brightest visual stars.) The Pleiades stars seen in X-rays have extremely hot, tenuous outer atmospheres called coronas and the range of colors corresponds to different coronal temperatures."<ref name=Nemiroff1999>{{ cite book |author=Robert Nemiroff |author2=Jerry Bonnell |title=X-Ray Pleiades |publisher=NASA/GSFC |location=Greenbelt, Maryland USA |date=August 28, 1999 |url=http://apod.nasa.gov/apod/ap990828.html |accessdate=2013-07-07 }}</ref> {{clear}} ==Ultraviolets== {{main|Radiation astronomy/Ultraviolets|Ultraviolet astronomy}} [[Image:August 2010 CME SDO.jpg|thumb|right|200px|A coronal mass ejection is shown in the ultraviolet. Credit: NASA/SDO.{{tlx|free media}}]] [[Image:STEREO B EUVI 171.jpg|thumb|left|250px|The chromosphere of the Sun shows in ultraviolets. Credit: STEREO (NASA).{{tlx|fairuse}}]] "One of the fastest CMEs in years was captured by the STEREO COR1 telescopes on August 1, 2010. ... This CME is seen to be heading towards Earth at speeds well over 1000 kilometers per second."<ref name=Zell/> "On August 1st, almost the entire Earth-facing side of the sun erupted in a tumult of activity. There was a C3-class solar flare, a solar tsunami, multiple filaments of magnetism lifting off the stellar surface, large-scale shaking of the solar corona, radio bursts, a coronal mass ejection and more. This extreme ultraviolet snapshot [at right] from the Solar Dynamics Observatory (SDO) shows the sun's northern hemisphere in mid-eruption. Different colors in the image represent different gas temperatures ranging from ~1 to 2 million degrees K."<ref name=Zell>{{ cite book |author=Holly Zell |title=Spacecraft Observes Coronal Mass Ejection |publisher=NASA |location=Washington, DC USA |date=August 4, 2010 |url=http://www.nasa.gov/topics/solarsystem/sunearthsystem/main/News080210-cme.html |accessdate=2013-07-07 }}</ref> {{clear}} ==Non-polar solar coronal holes== [[Image:Coronalhole.jpg|right|thumb|250px|Solar Disk with Coronal Hole - May 25, 2007 - by NASA STEREO (Solar TErrestrial RElations Observatory). Credit: NASA STEREO (Solar TErrestrial RElations Observatory).{{tlx|free media}}]] [[Image:417176main SDO Guide CMR Page 26 Image 0002.jpg|left|thumb|250px|A coronal hole is shown in extreme UV light. Credit: NASA.{{tlx|free media}}]] [[Image:Cor hole May-thumb-570x570-123594.jpg|thumb|right|250px|Coronal holes are areas on the Sun's corona that are darker, lower-density, and (relatively) colder than the rest of the plasma above the surface of our nearest star. Credit: NASA.{{tlx|fairuse}}]] [[Image:Two Coronal Holes on the Sun Viewed by SDO (16658479920).jpg|left|thumb|250px|NASA’s Solar Dynamics Observatory, or SDO, captured this solar image on March 16, 2015, which clearly shows two dark patches, known as coronal holes. Credit: NASA/Goddard/SDO.{{tlx|free media}}]] [[Image:Coronal Hole Front and Center.jpg|right|thumb|300px|The high-speed solar wind originating from this coronal hole, imaged hereon Oct. 10, 2015, by NASA's Solar Dynamics Observatory, created a geomagnetic storm near Earth that resulted in several nights of auroras. Credit: NASA/SDO.{{tlx|free media}}]] [[Image:PIA22197-SunFormsQuestionMark-20171222.jpg|left|thumb|250px|NASA's Solar Dynamics Observatory observed an elongated coronal hole (the darker area near the center) seeming to shape itself into a single, recognizable question mark over the period of one day (Dec. 21-22, 2017). Credit: NASA/GSFC/Solar Dynamics Observatory.{{tlx|free media}}]] "The striking absence of green emission above both polar regions at activity minimum led Waldmeier (1957) to use the German term 'Koronalöcher', ie, coronal holes."<ref name=Schwenn>{{ cite journal |author=R. Schwenn |author2=B. Inhester |author3=S. P. Plunkett |author4=A. Epple |author5=B. Podlipnik |author6=D. K. Bedford |author7=C. J. Eyles |author8=G. M. Simnett |author9=S. J. Tappin |author10=M. V. Bout |author11=et al. |title=First View of the Extended Green-Line Emission Corona At Solar Activity Minimum Using the Lasco-C1 Coronagraph on Soho |journal=Solar Physics |month=October |year=1997 |volume=175 |issue=2 |pages=667-84 |url=http://www.springerlink.com/index/R10HN0R60R081237.pdf |arxiv= |bibcode= |doi=10.1023/A:1004948913883 |pmid= |accessdate=2012-02-17 }}</ref> "Here we restrict ourselves to a qualitative study of large scale structures of the green emission line corona."<ref name=Schwenn/> The image descriptions that follow emphasize various non-polar holes. For the coronal hole from 25 May 2007: the image of the solar coronal cloud at top right shows both of the polar coronal holes and one apparently isolated, non-polar coronal hole. Second image down on the right: "Coronal holes are areas on the sun's corona that are darker, lower-density, and (relatively) colder than the rest of the plasma on the surface of our nearest star. They're the source of the kind of solar wind gusts that carry solar particles out to our magnetosphere and beyond, causing auroras (and, less awesomely, geomagnetic storms) here on Earth."<ref name=Garber>{{ cite book |author=Megan Garber |title=No Big Deal, Just a Giant Hole in the Sun |publisher=The Atlantic |location= |date=5 June 2013 |url=http://www.theatlantic.com/technology/archive/2013/06/no-big-deal-just-a-giant-hole-in-the-sun/276564/ |accessdate=2015-05-18 }}</ref> "When coronal holes are captured in extreme ultraviolet light images, they reveal themselves as dark spots that appear, to human eyes, to be plasma voids."<ref name=Garber/> "Well, last week -- between May 28 and 31 -- one of those coronal holes rotated toward Earth. It was a big one: "one of the largest," NASA says, "we have seen in a year or more." And the Solar Dynamics Observatory's Atmospheric Imaging Assembly, fortunately, got a shot of the thing. Above, via a combination of three wavelengths of UV light, is an image of the hole. It's pretty gorgeous, as holes go."<ref name=Garber/> "And while coronal holes are more likely to affect Earth after they've rotated more than halfway around the visible hemisphere of the sun -- which was the case with this guy -- the most this one would have done, astronomers say, was to generate some aurora."<ref name=Garber/> The image second down on the right shows one of the largest non-polar coronal holes ever observed in May, apparently in 2013. For the second image down on the left: "NASA’s Solar Dynamics Observatory, or SDO, captured this solar image on March 16, 2015, which clearly shows two dark patches, known as coronal holes. The larger coronal hole of the two, near the southern pole, covers an estimated 6- to 8-percent of the total solar surface. While that may not sound significant, it is one of the largest polar holes scientists have observed in decades. The smaller coronal hole, towards the opposite pole, is long and narrow. It covers about 3.8 billion square miles on the sun - only about 0.16-percent of the solar surface."<ref name=Goddard2015>{{ cite book |author=NASA/Goddard/SDO |title=Two Coronal Holes on the Sun Viewed by SDO |publisher=Goddard Space Flight Center |location=Greenbelt, Maryland USA |date=17 March 2015 |editor= |pages=1 |url=https://www.flickr.com/people/24662369@N07 |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2018-02-07 }}</ref> Per the third image down on the right: "The dark area across the top of the sun in this image is a coronal hole, a region on the sun where the magnetic field is open to inter planetary space, sending coronal material speeding out in what is called a high-speed solar wind stream. The high-speed solar wind originating from this coronal hole, imaged hereon Oct. 10, 2015, by NASA's Solar Dynamics Observatory, created a geomagnetic storm near Earth that resulted in several nights of auroras. This image was taken in wavelengths of 193 Angstroms, which is invisible to our eyes and is typically colorized in bronze."<ref name=NASA>{{ cite book |author=NASA/SDO |title=Coronal Hole Front and Center |publisher=GSFC |location=Greenbelt, Maryland USA |date=15 October 2015 |editor= |pages=1 |url=https://www.nasa.gov/image-feature/goddard/coronal-hole-front-and-center |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2018-02-07 }}</ref> Relative to the third image down on the left: "Oddly enough, an elongated coronal hole (the darker area near the center) seems to shape itself into a single, recognizable question mark over the period of one day (Dec. 21-22, 2017). Coronal holes are areas of open magnetic field that appear darker in extreme ultraviolet light, as is seen here. These holes are the source of streaming plasma that we call solar wind."<ref name=Dynamics>{{ cite web |author=NASA/GSFC/Solar Dynamics Observatory |title=PIA22197: The Sun Forms a Question |publisher=GSFC |location=Greenbelt, Maryland USA |date=29 December 2017 |editor= |pages=1 |url=https://photojournal.jpl.nasa.gov/jpeg/PIA22197.jpg |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2018-02-07 }}</ref> While the hole is connected to the polar coronal hole it does extend to mid-latitudes. {{clear}} ==Saturn== "Saturn's corona plays a major role in supplying hydrogen to the circumplanetary volume."<ref name=Smyth>{{ cite web |author=W.H. Smyth, M.R. Combi |title=Extended atmospheres of outer planet satellites and comets. Interim report, 15 June-14 September 1987 |publisher= |location= |date=November 1, 1987 |pages=122 |url=http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=5275119 |accessdate=2013-07-10 }}</ref> "This cloud probably connects to the extended hydrogen corona of Saturn (Broadfoot et al., 1981; Shemansky and Hall, 1992) and to hydrogen-rich icy surfaces in the inner magnetosphere."<ref name=Young>{{ cite journal |author=D. T. Young |author2=J. J. Berthelier |author3=M. Blanc |author4=J. L. Burch |author5=A. J. Coates |author6=R. Goldstein |author7=M. Grande |author8=T. W. Hill |author9=R. E. Johnson |author10=V. Kelha |author11=D. J. Mccomas |author12=E. C. Sittler |author13=K. R. Svenes |author14=K. Szegö |author15=P. Tanskanen |author16=K. Ahola |author17=D. Anderson |author18=S. Bakshi |author19=R. A. Baragiola |author20=B. L. Barraclough |author21=R. K. Black |author22=S. Bolton |author23=T. Booker |author24=R. Bowman |author25=P. Casey |author26=F. J. Crary |author27=D. Delapp |author28=G. Dirks |author29=N. Eaker |author30=H. Funsten |author31=J. D. Furman |author32=J. T. Gosling |author33=H. Hannula |author34=C. Holmlund |author35=H. Huomo |author36=J. M. Illiano |author37=P. Jensen |author38=M. A. Johnson |author39=D. R. Linder |author40=T. Luntama |author41=S. Maurice |author42=K. P. Mccabe |author43=K. Mursula |author44=B. T. Narheim |author45=J. E. Nordholt |author46=A. Preece |author47=J. Rudzki |author48=A. Ruitberg |author49=K. Smith |author50=S. Szalai |author51=M. F. Thomsen |author52=K. Viherkanto |author53=J. Vilppola |author54=T. Vollmer |author55=T. E. Wahl |author56=M. Wüest |author57=T. Ylikorpi |author58=C. Zinsmeyer |title=Cassini plasma spectrometer investigation |journal=Space Science Reviews |month=September |year=2004 |volume=114 |issue=1-4 |pages=1-112 |url=http://link.springer.com/article/10.1007/s11214-004-1406-4 |arxiv= |bibcode= |doi=10.1007/s11214-004-1406-4 |pmid= |accessdate=2013-07-10 }}</ref> ==Brown dwarfs== [[Image:Lp94420 duo m.jpg|thumb|250px|[[w:Chandra X-ray Observatory|Chandra]] image of LP 944-20 before flare and during flare. Credit: NASA.{{tlx|free media}}]] Some brown dwarfs emit X-rays. Here are some X-ray milestones from the same article: * 1998: First X-ray-emitting brown dwarf found. Cha Halpha 1, an M8 object in the [[w:Chamaeleon I|Chamaeleon I]] dark cloud, is determined to be an X-ray source, similar to convective late-type stars. * December 15, 1999: First X-ray flare detected from a brown dwarf. A team at the University of California monitoring LP 944-20 (60 Jupiter masses, 16 ly away) via the [[w:Chandra X-ray Observatory|Chandra X-ray Observatory]], catches a 2-hour flare. X-ray flares detected from brown dwarfs since late 1999 suggest changing [[w:magnetic field of celestial bodies|magnetic fields]] similar to those in very low-mass stars. When combined with the rapid rotation that most brown dwarfs exhibit, conditions [may exist] for the development of a strong, tangled [[w:magnetic field|magnetic field]] near the surface. The flare observed by [[w:Chandra X-ray Observatory|Chandra]] from LP 944-20 could have its origin in the turbulent magnetized hot material that may conduct heat to the atmosphere, allowing electric currents to flow and produce an X-ray flare, like a stroke of [[w:lightning|lightning]]. The absence of X-rays from LP 944-20 during the non flaring period is also a significant result. It sets the lowest observational limit on steady X-ray power produced by a brown dwarf star, and shows that coronas cease to exist as the surface temperature of a brown dwarf cools below about 2500°C and becomes electrically neutral. Using NASA's [[w:Chandra X-ray Observatory|Chandra X-ray Observatory]], scientists have detected X-rays from a low-mass brown dwarf in a multiple star system.<ref name=Williams2003>{{ cite book |date=14 April 2003 |title=X-rays from a Brown Dwarf's Corona |url=http://www.williams.edu/Astronomy/jay/chapter18_etu6.html }}</ref> This is the first time that a brown dwarf this close to its parent star(s) (Sun-like stars TWA 5A) has been resolved in X-rays.<ref name=Williams2003/> "Our Chandra data show that the X-rays originate from the brown dwarf's coronal plasma which is some 3 million degrees Celsius", said Yohko Tsuboi of [[w:Chuo University|Chuo University]] in Tokyo.<ref name=Williams2003/> "This brown dwarf is as bright as the Sun today in X-ray light, while it is fifty times less massive than the Sun", said Tsuboi.<ref name=Williams2003/> "This observation, thus, raises the possibility that even massive planets might emit X-rays by themselves during their youth!"<ref name=Williams2003/> {{clear}} ==Heliophysics== {{main|Stars/Sun/Heliophysics|Heliophysics}} "Heliophysics is concerned with laws that give rise to structures and processes that occur in magnetized plasmas and in neutral environments in the local cosmos, both temporal (weather-like) and persistent (climate-like). These laws systematize the results of half a century of exploring space that followed centuries of ground-based observations. During this time spacecraft have imaged the Sun over many wavelengths and resolutions. They have visited every planet, all major satellites and many minor ones, and a selection of comets and asteroids. Beyond this they have traversed the expanse of the [[heliosphere]] itself. Out of the vast store of data so accumulated, the laws and principles of heliophysics are emerging to describe structures that are natural to magnetized plasmas and neutrals in cosmic settings and to specify principles that make the heliosphere a realm of numerous, original dynamical modes."<ref name=Siscoe>{{ cite book |author=George L. Siscoe |author2=Carolus J. Schrijver |title=Perspective on heliophysics, In: ''Heliophysics: Space Storms and Radiation: Causes and Effects'' |publisher=Cambridge University Press |location=Cambridge, UK |date=May 2010 |editor=Carolus J. Schrijver |editor2=George L. Siscoe |pages=1-10 |url=http://www.langtoninfo.com/web_content/9780521760515_excerpt.pdf |arxiv= |bibcode= |doi= |pmid= |isbn=978-0-521-76051-5 |accessdate=2014-08-02 }}</ref> "In the case of heliophysics, probably most of its laws have yet to be discovered, since the project of finding them is young. Moreover, heliophysics is a unique hybrid between meteorology and astrophysics with substantial components of physics and chemistry. Thus, many of the laws of heliophysics that we can list at this time might be subjects for research in meteorology (e.g. the field of aeronomy), astrophysics (e.g. shock waves and cosmic rays), physics (e.g. magnetic reconnection and particle energization), or chemistry (e.g. reaction rates in planetary ionospheres and thermospheres)."<ref name=Siscoe/> ==Magnetohydrodynamics== "When magnetic fields "reconnect" in a turbulent magnetohydrodynamic (MHD) plasma, electric fields are generated in which particles can be accelerated (Matthaeus ''et al.'', 1984; Sorrell, 1984)."<ref name="Gaisser">{{cite book |author=Thomas K. Gaisser |title=Cosmic Rays and Particle Physics |publisher=Cambridge University Press |location= |year=1990 |editor= |pages=279 |url=http://books.google.com/books?hl=en&lr=&id=qJ7Z6oIMqeUC&oi=fnd&pg=PR15&ots=IxjwLxBwXu&sig=voHKIYstBlBYla4jcbur_b-Zwxs |arxiv= |bibcode= |doi= |pmid= |isbn=0521339316 |accessdate=2014-01-11 }}</ref> ==Stellar sciences== {{main|Stars/Sciences}} [[Image:November 3 2009 GOES14 Image.png|thumb|left|250px|The GOES 14 spacecraft took this image of the '''Sun'''. Credit: NOAA/Space Weather Prediction Center and the NWS Internet Services Team.{{tlx|free media}}]] The GOES 14 spacecraft carries a Solar X-ray Imager that took this image [at right] of the '''Sun''' during the most recent quiet period. The Sun appears dark because of the wavelength band of observation and the lack of X-rays. Except for X-ray emission that suggests a circular disc with some isolated X-ray sources at specific locations, the Sun is almost invisible. X-rays are primarily emitted from plasmas near 10⁶ K. {{clear}} ==Focusing Optics X-ray Solar Imagers== [[Image:FOXSI-2 sounding rocket.jpg|thumb|left|250px|The photograph shows the FOXSI team in front of the FOXSI-2 sounding rocket on the launch pad. Credit: NASA, Säm Krucker, UC Berkeley.{{tlx|fairuse}}]] [[Image:FOXSI-2 Sounding Rocket Payload.png|thumb|right|250px|A high resolution render shows the FOXSI-2 payload. Credit: [[w:user:Schriste|Schriste]].{{tlx|fairuse}}]] The Focusing Optics X-ray Solar Imager, or FOXSI, is a sounding rocket payload built to observe the Sun, composed of seven identical Wolter-I telescope modules, as well as Silicon and Cadmium Telluride strip detectors originally developed for the HXT telescope on the Japanese Hitomi mission. The FOXSI payload flew two times,<ref> {{cite web | url = https://www.nasa.gov/content/goddard/nasa-funded-foxsi-to-observe-x-rays-from-sun | title = NASA-funded FOXSI to Observe X-Rays From Sun | last = Fox | first = Karen | date =November 1, 2015 | publisher = NASA | accessdate= July 28, 2015 }}</ref><ref>{{cite web | url = http://www.nasa.gov/mission_pages/sounding-rockets/news/xray-scope.html#.VbbtWnh41FI | title = A Next-Generation X-Ray Telescope Launches | last = Fox | first = Karen | date = July 27, 2015 | publisher = NASA | accessdate= July 27, 2015 }}</ref> and previously in 2012. Like most sounding rockets, FOXSI flew for approximately 15 minutes per mission and observed the Sun for about 5 minutes while in space. During its first flight, FOXSI successfully imaged a solar microflare in the hard x-ray band for the first time.<ref name=Krucker>{{cite journal |title=First Images from the Focusing Optics X-Ray Solar Imager |journal= The Astrophysical Journal Letters |volume=793 |issue= 2 |page=L32 |date=2014 |bibcode=2014ApJ...793L..32K |doi = 10.1088/2041-8205/793/2/L32 |last=Krucker | first=S. |last2=Christe | first2=S. |last3=Glesener|first3=L. |last4= Ishikawa|first4=S. |last5=Ramsey|first5=B. |last6=Takahashi|first6=T. |last7=Watanabe|first7=S. |last8=Saito|first8=S. |last9=Gubarev|first9=M. }}</ref> FOXSI's third mission had a successful launch on September 7, 2018 from White Sands, New Mexico, which included a combination of Silicon and improved Cadmium Telluride detectors,<ref name=Ishikawa>{{Cite journal |last=Ishikawa|first=S. |last2=Katsuragawa|first2=M. |last3=Watanabe|first3=S. |last4=Uchida|first4=Y. |last5=Takeda|first5=S. |last6=Takahashi|first6=T. |last7=Saito|first7=S. |last8=Glesener|first8=L. |last9=Buitrago-Casas|first9=J. C. |date=2016 |title=Fine-pitch CdTe detector for hard X-ray imaging and spectroscopy of the Sun with the FOXSI rocket experiment |journal=Journal of Geophysical Research: Space Physics |language=en |volume=121 |issue=7 |pages=6009–6016 |doi=10.1002/2016ja022631|issn=2169-9402|arxiv=1606.03887|bibcode=2016JGRA..121.6009I}}</ref> as well as one CMOS soft x-ray detector. Two of the telescope modules were updated from 7-shell to 10-shell configurations, and the payload also introduced collimator technology to reduce the impact of singly-reflected rays.<ref name=Buitrago>{{Cite book |last=Buitrago-Casas|first=J. C. |last2=Glesener|first2=L. |last3=Christe|first3=S. |last4=Ramsey|first4=B. |last5=Elsner|first5=R. |last6=Courtade|first6=S. |last7=Vievering|first7=J. |last8=Subramania|first8=A. |last9=Krucker|first9=S. |last10=Bale|first10=S. |date=2017 |title=Methods for reducing singly reflected rays on the Wolter-I focusing mirrors of the FOXSI rocket experiment, In: ''Optics for EUV, X-Ray, and Gamma-Ray Astronomy VIII'' |series=Proceedings of SPIE |volume=10399 |page=103990J |bibcode=2017SPD....4830504B |doi=10.1117/12.2274675 |{{isbn|9781510612556}} }}</ref> {{clear}} ==See also== {{div col|colwidth=20em}} * [[Plasmas/Plasma objects/Coronal clouds|Coronal clouds]] * [[Radiation/Cosmic rays|Cosmic-ray astronomy]] * [[Radiation astronomy/Electrons|Electron astronomy]] * [[Radiation astronomy/Fieries|Fiery meteor astronomy]] * [[Stars/Flares|Flare stars]] * [[Stars/Sun/Heliophysics|Heliophysics]] * [[Radiation astronomy/Lightnings|Lightning astronomy]] * [[Radiation astronomy/Nebulas|Nebula astronomy]] * [[Stars/Nova-likes|Nova-like stars]] * [[Stars/Novas|Novas]] * [[Stars/Os|O-type stars]] * [[Radiation astronomy/Protons|Proton astronomy]] * [[Stars/Quasars|Quasars]] * [[Stars/Star fissions|Star fissions]] * [[Stars/Active regions|Stellar active regions]] * [[Stars/Surface fusion|Surface fusions]] * [[Stars/Supernovas|Supernovas]] * [[Stars/Variables|Variable stars]] * [[Stars/Wolf-Rayets|Wolf-Rayet stars]] * [[Stars/X-rays|X-ray stars]] {{Div col end}} ==References== {{reflist|2}} ==External links== * [http://www.adsabs.harvard.edu/ The SAO/NASA Astrophysics Data System] * [http://simbad.u-strasbg.fr/simbad/ SIMBAD Astronomical Database] <!-- footer templates --> {{Radiation astronomy resources}}{{Sisterlinks|Plasma radiation astronomy}} <!-- footer categories --> [[Category:Radiation astronomy/Lectures]] 9umvrju5jzmj7lc72dii33t8y8lb3jm 2414050 2414027 2022-08-13T07:59:53Z Marshallsumter 311529 /* Starquakes */ wikitext text/x-wiki [[Image:Media 1.ogv|thumb|right|250px|On July 19, 2012, an eruption occurred on the sun that produced a moderately powerful solar flare and a dazzling magnetic display known as coronal rain. Credit: NASA Goddard Space Flight Center, Music: 'Thunderbolt' by Lars Leonhard, courtesy of artist.{{tlx|free media}}]] A [[coronal cloud]] is a cloud, or cloud-like, natural astronomical entity, composed of plasma and usually associated with a star or other astronomical object where the temperature is such that X-rays are emitted. While small coronal clouds are above the photosphere of many different visual spectral type stars, others occupy parts of the [[interstellar medium]] (ISM), extending sometimes millions of kilometers into space, or thousands of light-years, depending on the size of the associated object such as a galaxy. {{clear}} ==Auroras== {{main|Plasmas/Plasma objects/Auroras}} [[Image:Aurora Iceland 2015 Carlos Gauna 625.jpg|thumb|right|300px|This dramatic panorama shows a colourful, shimmering auroral curtain reflected in a placid Icelandic lake. Credit: Carlos Gauna. {{tlx|fairuse}}]] '''Auroras''' can be caused by electrons being absorbed into an atmosphere. The "dramatic panorama [on the right shows a colorful], shimmering auroral curtain reflected in a placid Icelandic lake. The image was taken on 18 March 2015 by Carlos Gauna, near Jökulsárlón Glacier Lagoon in southern Iceland."<ref name=ESAGauna>{{ cite book |author=European Space Agency |title=Aurora over Icelandic Lake |publisher=ESA |location= |date=9 April 2015 |url=http://sci.esa.int/cluster/55767-aurora-over-icelandic-lake/ |accessdate=2015-04-12 }}</ref> "The celestial display was generated by a coronal mass ejection, or CME, on 15 March. Sweeping across the inner Solar System at some 3 million km per hour, the eruption reached Earth, 150 million kilometres away, in only two days. The gaseous cloud collided with Earth’s magnetic field at around 04:30 GMT on 17 March."<ref name=ESAGauna/> "When the charged particles from the Sun penetrate Earth's magnetic shield, they are channelled downwards along the magnetic field lines until they strike atoms of gas high in the atmosphere. Like a giant fluorescent neon lamp, the interaction with excited oxygen atoms generates a green or, more rarely, red glow in the night sky, while excited nitrogen atoms yield blue and purple colours."<ref name=ESAGauna/> "Auroral displays are not just decorative distractions. They are most frequent when the Sun's activity nears its peak roughly every 11 years. At such times, the inflow of high-energy particles and the buffeting of Earth’s magnetic field may sometimes cause power blackouts, disruption of radio communications, damage to satellites and even threaten astronaut safety."<ref name=ESAGauna/> {{clear}} ==Coronas== [[Image:PSM V60 D316 The solar corona.png|thumb|right|250px|The solar corona is photographed between 1901-2. Credit: [http://www.archive.org/details/popularsciencemo60newy Popular Science Monthly Volume 60].{{tlx|free media}}]] [[Image:Cp19halphajune29.png|thumb|left|250px|This is a coronagraph/polarimeter image of the solar corona on June 29, 1980, in H alpha light. Credit: NASA.{{tlx|free media}}]] '''Def.''' "[t]he luminous plasma atmosphere of the Sun or other star, extending millions of kilometres into space, most easily seen during a total solar eclipse"<ref name=CoronaWikt>{{ cite web |title=corona |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=6 September 2015 |url=https://en.wiktionary.org/wiki/corona |accessdate=2015-09-10 }}</ref> is called a '''corona''', or '''stellar corona'''. "Beginning with the daguerreotype of the corona of 1851, the Reverend Lecturer had thrown on the screen pictures illustrating the form of the corona in different years. The drawings of those of 1867, 1878, and 1900 all showed long equatorial extensions with openings at the solar poles filled with beautiful rays."<ref name=Cortie>{{ cite journal |author=A. L. Cortie |title=Synopsis of Lecture on "The Solar Corona" by the Rev. A.L. Cortie to the Members of the North-Western Branch (Manchester) on 7th November 1900 |journal=Journal of the British Astronomical Association |month=December |year=1900 |volume=11 |issue=12 |pages=77-8 |url=http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1900JBAA...11...77C&link_type=ARTICLE&db_key=AST&high= |arxiv= |bibcode=1900JBAA...11...77C |doi= |pmid= |accessdate=2011-11-09 }}</ref> "The intermediate years, as, for example, 1883, 1886, and 1896 showed the four groups of synclinals which mainly constitute the corona gradually descending towards the equator of the sun, with a corresponding opening of the polar regions."<ref name=Cortie/> "Some of the theories of the solar corona were then illustrated and discussed."<ref name=Cortie/> # "The corona is not of the nature of an atmosphere round the sun, for the pressure at the sun's limb would be enormous, while the thinness of the chromospheric lines show that it is not."<ref name=Cortie/> # "comets, such as that of 1843, have approached the sun with enormous velocities within the region of the prominences without suffering disruption or retardation."<ref name=Cortie/> # "If not an atmosphere of particles of gas, still less is it an atmosphere of solid stones or meteorites."<ref name=Cortie/> # "Meteor streams do circle round the sun, but there is no reason why the positions of the orbits, or the intrinsic brightness of such streams should vary with the sun-spot period."<ref name=Cortie/> # "the appearance of the corona does not seem to be such as the projection of meteor streams upon the celestial vault would give."<ref name=Cortie/> # "Prof. Schaeberle has proposed a mechanical origin of the solar corona, due to the forces of ejection of particles from the solar limb, as evidenced by the prominences, and the force of gravity under the particular conditions of the solar rotation and the inclination of its axis to the earth's orbit."<ref name=Cortie/> # "The electrical theory of the corona does not negative the mechanical theory, but supplements it. In addition to the forces of gravity and ejection, it takes account of the repulsive force which the sun exerts on matter which has the same electrical sign as itself, and which has been ejected from it."<ref name=Cortie/> # "it would seem that the solar corona is of the nature of an electrical aurora round the sun."<ref name=Cortie/> # "the coronoidal discharges in poor vacua obtained by Prof. Pupin about an insulated metal ball are exceedingly like the rays and streamers of the solar corona."<ref name=Cortie/> The Sun's hot corona continuously expands in space creating the solar wind, a stream of charged particles that extends to the heliopause at roughly 100 astronomical units. The bubble in the [[interstellar medium]] formed by the solar wind, the heliosphere, is the largest continuous structure in the Solar System.<ref>{{ cite web |date=22 April 2003 |title=A Star with two North Poles |url=http://science.nasa.gov/headlines/y2003/22apr_currentsheet.htm |work=Science @ NASA |publisher=NASA }}</ref><ref name=Riley>{{ cite journal |last=Riley |first=P. |last2=Linker |first2=J. A. |last3=Mikić |first3=Z. |year=2002 |title=Modeling the heliospheric current sheet: Solar cycle variations |url=http://ulysses.jpl.nasa.gov/science/monthly_highlights/2002-July-2001JA000299.pdf |journal=Journal of Geophysical Research |volume=107 |issue=A7 |pages=SSH 8–1 |bibcode=2002JGRA.107g.SSH8R |doi=10.1029/2001JA000299 |id=CiteID 1136 }}</ref> The sun's corona is constantly being lost to space, creating what is essentially a very thin atmosphere throughout the [[Solar System]]. The movement of mass ejected from the Sun is known as the solar wind. Inconsistencies in this wind and larger events on the surface of the star, such as coronal mass ejections, form a system that has features analogous to conventional weather systems (such as pressure and wind) and is generally known as space weather. Coronal mass ejections have been tracked as far out in the [[solar system]] as Saturn.<ref name=Christensen>Bill Christensen. [http://www.space.com/businesstechnology/technology/technovel_shock_041105.html Shock to the (Solar) System: Coronal Mass Ejection Tracked to Saturn.] Retrieved on 28 June 2008.</ref> The activity of this system can affect planetary atmospheres and occasionally surfaces. The interaction of the solar wind with the terrestrial atmosphere can produce spectacular aurorae,<ref name=AlaskaReport>AlaskaReport. [http://alaskareport.com/science10043.htm What Causes the Aurora Borealis?] Retrieved on 28 June 2008.</ref> and can play havoc with electrically sensitive systems such as electricity grids and radio signals. {{clear}} ==Coronal arcades== [[Image:Coronal_arcade.png|thumb|right|250px|This is a TRACE image of the coronal arcade structure in the flare on Bastille Day, 1998. Credit: NASA.{{tlx|free media}}]] '''Def.''' a close collection of loops in a cylindrical structure is called an '''arcade'''. The TRACE image at right "is from near flare maximum (11:00 UT) and has a width of 230,000 km [...] how in the world can the footpoints of the arcade have such a clearly-organized pattern whose scale greatly exceeds the known scales of the largest convective scales known in the photosphere?"<ref name=Handy>{{ cite book |author=Brian Handy, Hugh Hudson |title=Super Regions |publisher=University of Montana |location=Helena, Montana, USA |date=July 14, 2000 |url=http://solar.physics.montana.edu/nuggets/2000/000714/000714.html |accessdate=2012-11-09 }}</ref> "The most obvious coronal signatures of CMEs in the low corona are the arcades of bright loops that develop after the CME material has erupted [...] nearly all (92%) EIT post-eruptive arcades from 1997 – 2002 were associated with LASCO CMEs [...] The activity associated with halo CMEs includes the formation of dimming regions, long-lived loop arcades, flaring active regions, large-scale coronal waves and filament eruptions".<ref name=Webb>{{ cite journal |author=David F. Webb, Timothy A. Howard |title=Coronal Mass Ejections: Observations |journal=Living Reviews in Solar Physics |year=2012 |volume=9 |issue= |pages=3 |url=http://www.boulder.swri.edu/~howard/Papers/2012_lrsp.pdf |arxiv= |bibcode= |doi= |pmid= |accessdate=2012-11-11 }}</ref> {{clear}} ==Coronal clouds== [[Image:2011 03 sun030311.jpg|thumb|right|200px|This image is taken in Hα of the Sun and above showing a cloud above a sunspot. Credit: Alan Friedman.{{tlx|fairuse}}]] "Coronal clouds, type IIIg, form in space above a spot area and rain streamers upon it."<ref name=Pettit43>{{ cite journal |author=Edison Pettit |title=The Properties of Solar Prominences as Related to Type |journal=Astrophysical Journal |month=July |year=1943 |volume=98 |issue=7 |pages=6-19 |url= |bibcode=1943ApJ....98....6P |doi=10.1086/144539 |pmid= |accessdate=2011-08-01 }}</ref> "[C]oronal magnetic bottles, produced by flares, [may] serve as temporary traps for solar cosmic rays ... It is the expansion of these bottles at velocities of 300–500 km/s which allows fast azimuthal propagation of solar cosmic rays independent of energy. A coronagraph on [[w:OSO 7|Os 7]] observed a coronal cloud which was associated with bifurcation of the underlying coronal structure."<ref name="Schatten">{{cite journal |author=K. H. Schatten, D. J. Mullan |title=Fast azimuthal transport of solar cosmic rays via a coronal magnetic bottle |journal=Journal of Geophysical Research |month=December 1, |year=1977 |volume=82 |issue=35 |pages=5609-20 |url=http://www.agu.org/pubs/crossref/1977/JA082i035p05609.shtml |arxiv= |bibcode= |doi=10.1029/JA082i035p05609 |pmid= |accessdate=2013-07-07 }}</ref> In a coronal cloud are [[Magnetohydrodynamics|magnetohydrodynamic]] plasma flux tubes along magnetic field lines.<ref name=Aschwanden/> {{clear}} ==Coronal heating== "The photosphere of the Sun has an effective temperature of 5,570 K<ref name=Massey>{{ cite journal |author=Massey P |author2=Silva DR |author3=Levesque EM |author4=Plez B |author5=Olsen KAG |author6=Clayton GC |author7=Meynet G |author8=Maeder A |title=Red Supergiants in the Andromeda Galaxy (M31) |journal=The Astrophysical Journal |volume=703 |year=2009 |issue=1 |page=420 |doi=10.1088/0004-637X/703/1/420 |bibcode=2009ApJ...703..420M }}</ref> yet its corona has an average temperature of 1–2 x 10⁶ K.<ref name=Erdelyi>{{ cite journal |author=Erdèlyi R |author2=Ballai I |title=Heating of the solar and stellar coronae: a review |year=2007 |journal=Astron Nachr |volume=328 |issue=8 |page=726 |doi=10.1002/asna.200710803 |bibcode=2007AN....328..726E }}</ref> However, the hottest regions are 8–20 x 10⁶ K.<ref name=Erdelyi/> The high temperature of the corona shows that it is heated by something other than direct [[w:Heat conduction|heat conduction]] from the photosphere.<ref name=Russell2001>{{ cite book |author=Russell CT |title=Space Weather (Geophysical Monograph) |year=2001 |publisher=American Geophysical Union |chapter=Solar wind and interplanetary magnetic field: A tutorial |editor=Song, Paul |editor2=Singer, Howard J. |editor3=Siscoe, George L. |isbn=9780875909844 |pages=73–88 |url=http://www-ssc.igpp.ucla.edu/personnel/russell/papers/SolWindTutorial.pdf }}</ref> It is thought that the energy necessary to heat the corona is provided by turbulent motion in the convection zone below the photosphere, and two main mechanisms have been proposed to explain coronal heating.<ref name=Erdelyi/> The first is [[w:wave|wave]] heating, in which sound, gravitational or magnetohydrodynamic waves are produced by turbulence in the convection zone.<ref name=Erdelyi/> These waves travel upward and dissipate in the corona, depositing their energy in the ambient gas in the form of heat.<ref name=Alfven>{{ cite journal |author=Alfvén H |title=Magneto-hydrodynamic waves, and the heating of the solar corona |bibcode=1947MNRAS.107..211A |journal=Monthly Notices of the Royal Astronomical Society |volume=107 |page=211 |year=1947 }}</ref> The other is [[w:magnetic field|magnetic]] heating, in which magnetic energy is continuously built up by photospheric motion and released through [[w:magnetic reconnection|magnetic reconnection]] in the form of large [[w:solar flare|solar flare]]s and myriad similar but smaller events—[[w:nanoflares|nanoflares]].<ref name=Parker2>{{ cite journal |author=Parker EN |title=Nanoflares and the solar X-ray corona |journal=The Astrophysical Journal |volume=330 |page=474 |year=1988 |doi=10.1086/166485 |bibcode=1988ApJ...330..474P }}</ref> Currently, it is unclear whether waves are an efficient heating mechanism. All waves except [[w:Alfvén wave|Alfvén wave]]s have been found to dissipate or refract before reaching the corona.<ref name=Sturrock>{{ cite journal |author=Sturrock PA, Uchida Y |title=Coronal heating by stochastic magnetic pumping |journal=The Astrophysical Journal |volume=246 |page=331 |year=1981 |doi=10.1086/158926 |bibcode=1981ApJ...246..331S }}</ref> In addition, Alfvén waves do not easily dissipate in the corona. Current research focus has therefore shifted towards flare heating mechanisms.<ref name=Erdelyi/>"<ref name=XrayAstronomy>{{ cite web |title=X-ray astronomy, In: ''Wikipedia'' |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=June 11, 2012 |url=http://en.wikipedia.org/wiki/X-ray_astronomy |accessdate=2012-06-29 }}</ref> ==Coronal loops== [[Image:AR1520 and Shimmering Coronal Loops.ogv|thumb|250px|right|This movie shows the evolution of active region 1520, including coronal loops. Credit: NASA/Goddard Space Flight Center.{{tlx|free media}}]] [[Image:Traceimage.jpg|thumb|right|250px|This image of coronal loops observed by the Transition Region And Coronal Explorer ([[w:TRACE|TRACE]]) shows that not all rays travel in straight lines. Credit: NASA.{{tlx|free media}}]] Coronal loops have become very important when trying to understand the current ''coronal heating problem''. Coronal loops are highly radiating sources of plasma and therefore easy to observe by instruments such as ''TRACE''; they are highly observable ''laboratories'' to study phenomena such as solar oscillations, wave activity and [[w:Nanoflares|nanoflares]]. However, it remains difficult to find a solution to the coronal heating problem as these structures are being observed remotely, where many ambiguities are present (i.e. radiation contributions along the [line-of-sight propagation] LOS). ''In-situ'' measurements are required before a definitive answer can be arrived at, but due to the high plasma temperatures in the corona, in-situ measurements are impossible (at least for the time being). The next mission of the Nasa [[w:Solar Probe Plus|Solar Probe Plus]] will approach the Sun very closely allowing more direct observations. "The peak continuum intensity was always at the loop tops."<ref name=Zirin1981>{{ cite journal |author=H. Zirin |author2=U. Feldman |author3=G. A. Doschek |author4=S. Kane |title=On the relationship between soft X-rays and Hα-emitting structures during a solar flare |journal=The Astrophysical Journal |month=May 15, |year=1981 |volume=246 |issue=05 |pages=321-30 |url=http://adsabs.harvard.edu/full/1981ApJ...246..321Z |arxiv= |bibcode=1981ApJ...246..321Z |doi=10.1086/158925 |pmid= |accessdate=2013-07-10 }}</ref> The population of coronal loops can be directly linked with the [[w:solar cycle|solar cycle]]; it is for this reason coronal loops are often found with sunspots at their footpoints. Coronal loops project through the [[w:chromosphere|chromosphere]] and [[w:transition region|transition region]], extending high into the [[Coronal cloud|corona]]. Coronal loops have a wide variety of temperatures along their lengths. Loops existing at temperatures below 1&nbsp;MK are generally known as cool loops, those existing at around 1&nbsp;MK are known as warm loops, and those beyond 1&nbsp;MK are known as hot loops. Naturally, these different categories radiate at different wavelengths.<ref name=Vourlidas>{{cite journal | author = A. Vourlidas |author2=J. A. Klimchuk |author3=C. M. Korendyke |author4=T. D. Tarbell |author5=B. N. Handy | title = On the correlation between coronal and lower transition region structures at arcsecond scales | journal = The Astrophysical Journal | volume = 563 | issue = 1 | pages = 374–80 | year = 2001 | doi = 10.1086/323835 | bibcode=2001ApJ...563..374V }}</ref> Coronal loops populate both active and quiet regions of the solar surface. Active regions on the solar surface take up small areas but produce the majority of activity and 82% of the total coronal heating energy.<ref name=Aschwanden>{{ cite journal | author = M. J. Aschwanden | title = An evaluation of coronal heating models for Active Regions based on Yohkoh, SOHO, and TRACE observations | journal = The Astrophysical Journal | volume = 560 | issue = 2 | pages = 1035–44 | year = 2001 | doi = 10.1086/323064 | bibcode=2001ApJ...560.1035A }}</ref> The quiet Sun, although less active than active regions, is awash with [[w:dynamics (mechanics)|dynamic]] processes and [[w:transient astronomical event|transient]] events (bright points, nanoflares and jets).<ref name=Aschwanden04>{{ cite book | author = M. J. Aschwanden | title = Physics of the Solar Corona. An Introduction | publisher = Praxis Publishing Ltd. | date = 2004 | isbn = 3-540-22321-5 }}</ref> As a general rule, the quiet Sun exists in regions of closed magnetic structures, and active regions are highly dynamic sources of explosive events. It is important to note that observations suggest the whole corona is massively populated by open and closed magnetic fieldlines. A closed fieldline does not constitute a coronal loop; however, closed flux must be ''filled with plasma'' before it can be called a coronal loop. The image at right shows particle rays leaving the surface of the Sun (darker ends of the loops), traveling in a loop controlled by a local magnetic field similar to how particle accelerators accelerate, steer, and aim a stream of particles at a target (the much brighter regions in the chromosphere). The loops have a temperature of approximately 10⁶ K and are emitting X-rays (synchrotron and cyclotron radiation). Coronal loops form the basic structure of the lower corona andtransition region of the Sun. These highly structured and elegant loops are a direct consequence of the twisted solar magnetic flux within the solar body. The population of coronal loops can be directly linked with the solar cycle; it is for this reason coronal loops are often found with sunspots at their footpoints. The upwelling magnetic flux pushes through the photosphere, exposing the cooler plasma below. Loops of magnetic flux (closed flux tubes) well up from the solar body and fill with hot solar plasma.<ref name=Katsukawa>{{ cite journal |author=Yukio Katsukawa |author2=Saku Tsuneta |title=Magnetic Properties at Footpoints of Hot and Cool Loops |journal=The Astrophysical Journal |month=March |year=2005 |volume=621 |issue=1 |pages=498-511 |url=http://iopscience.iop.org/0004-637X/621/1/498/pdf/0004-637X_621_1_498.pdf |arxiv= |bibcode=2005ApJ...621..498K |doi=10.1086/427488 |pmid= |accessdate=2011-12-09 }}</ref> Due to the heightened magnetic activity in these coronal loop regions, coronal loops can often be the precursor to solar flares and coronal mass ejections (CMEs). {{clear}} ==Coronal mass ejections== {{main|Radiation/Meteors}} [[Image:Coronal Mass Ejection.gif|thumb|right|250px|Arcs rise above an active region on the surface of the Sun in this series of images taken by the STEREO (Behind) spacecraft. Credit: Images courtesy of the NASA STEREO Science Center.{{tlx|free media}}]] '''Def.''' a "massive burst of solar wind, other light isotope plasma, and magnetic fields rising above the solar corona or being released into space"<ref name=CoronalMassEjectionWikt>{{ cite book |title=coronal mass ejection |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=June 21, 2013 |url=http://en.wiktionary.org/wiki/coronal_mass_ejection |accessdate=2013-07-07 }}</ref> is called a '''coronal mass ejection''' (CME). An explosive limb flare occurred above 30,000 km in the corona of the [[Sun (star)|Sun]].<ref name=Zirin/> "So the aftermath of the flare explosion, usually visible in disk pictures as extensive Hα brightening, but hidden from us in this case, was seen by the ionosphere as an intense flux of ionizing radiation from the coronal cloud created by the explosion."<ref name=Zirin>{{ cite journal |author=Harold Zirin |title=The Limb Flare of November 20, 1960: a Coronal Phenomenon |journal=Astrophysical Journal |month=October |year=1964 |volume=140 |issue=10 |pages=1216-35 |url= |bibcode=1964ApJ...140.1216Z |doi=10.1086/148019 |pmid= |accessdate=2011-08-01 }}</ref> "The November 20, 1960, event is very similar to that of February 10, 1956, which was observed at Sacramento Peak. A bright ball appears above the surface, grows in size and Hα brightness, and explodes upward and outward."<ref name=Zirin/> "The great breadth and intensity of the Hα emission from the suspended ball at 2013 U.T. testify to the large amount of energy stored there, as no corresponding macroscopic motion was observed until the explosion at 2023 U.T."<ref name=Zirin/> "[T]he great energy of the preflare cloud was released into the corona by the explosion of 2023 U.T., and Hα radiation disappeared by 2035 U.T."<ref name=Zirin/> "On 16 June 1972, the [[w:Naval Research Laboratory|Naval Research Laboratory]]'s coronagraph aboard [[w:OSO-7|OSO-7]] tracked a huge coronal cloud moving outward from the [[Sun (star)|Sun]]."<ref name=Koomen>{{ cite journal |author=Martin Koomen |author2=Russell Howard |author3=Richard Hansen |author4=Shirley Hansen |title=The coronal transient of 16 June 1972 |journal=Solar Physics |month=February |year=1974 |volume=34 |issue=2 |pages=447-52 |url=http://link.springer.com/article/10.1007/BF00153680 |arxiv= |bibcode= |doi=10.1007/BF00153680 |pmid= |accessdate=2013-07-10 }}</ref> A [[w:coronal mass ejection|coronal mass ejection]] (CME) is an ejected plasma consisting primarily of electrons and [[w:proton|proton]]s (in addition to small quantities of heavier elements such as helium, oxygen, and iron), plus the entraining coronal closed magnetic field regions. Evolution of these closed magnetic structures in response to various photospheric motions over different time scales (convection, differential rotation, meridional circulation) somehow leads to the CME.<ref name=Gopalswamy>{{ cite journal |author=Gopalswamy N |author2=Mikic Z |author3=Maia D |author4=Alexander D |author5=Cremades H |author6=Kaufmann P |author7=Tripathi D |author8=Wang YM |title=The pre-CME Sun |journal=Space Sci Rev |year=2006 |volume=123 |issue=1–3 |page=303 |doi=10.1007/s11214-006-9020-2 |bibcode = 2006SSRv..123..303G }}</ref> Small-scale energetic signatures such as plasma heating (observed as compact soft X-ray brightening) may be indicative of impending CMEs. The soft X-ray sigmoid (an S-shaped intensity of soft X-rays) is an observational manifestation of the connection between coronal structure and CME production.<ref name=Gopalswamy/> "Relating the sigmoids at X-ray (and other) wavelengths to magnetic structures and current systems in the solar atmosphere is the key to understanding their relationship to CMEs."<ref name=Gopalswamy/> {{clear}} ==Coronal streamers== [[Image:Parker Solar Probe coronal stream wispr-big 1-st flyby.jpg|thumb|right|250px|This image from Parker Solar Probe's WISPR (Wide-field Imager for Solar Probe) instrument shows a coronal streamer, seen over the east limb of the Sun on Nov. 8, 2018, at 1:12 a.m. EST. Credit: NASA/NRL/Parker Solar Probe.{{tlx|free media}}]] The '''interconnections of active regions''' are arcs connecting zones of opposite magnetic field, in different active regions. Significant variations of these structures are often seen after a flare. Some other features of this kind are [[w:helmet streamer|helmet streamer]]s—large cap-like coronal structures with long pointed peaks that usually overlie sunspots and active regions. Coronal streamers are considered as sources of the slow [[w:solar wind|solar wind]].<ref name=Ofman>{{ cite journal | doi= 10.1029/2000GL000097 | last= Ofman | first= Leon | title= Source regions of the slow solar wind in coronal streamers | journal= Geophysical Research Letters | volume = 27 | issue= 18 | pages= 2885–8 |year=2000 | bibcode=2000GeoRL..27.2885O }}</ref> Coronal streamers are structures of solar material within the Sun's atmosphere, the corona, that usually overlie regions of increased solar activity. The fine structure of the streamer in the image on the right is very clear, with at least two rays visible. Parker Solar Probe was about 16.9 million miles from the Sun's surface when this image was taken. The bright object near the center of the image is Mercury, and the dark spots are a result of background correction. {{clear}} ==Dynamos== [[Image:SolarCycle25 Prediction Bhowmik Nandy 2018.jpg|thumb|right|250px|This figure is the outcome of the first ever century-scale, data driven, coupled solar surface flux transport model and solar internal dynamo model simulation which was utilized to predict the amplitude and timing of sunspot cycle 25. Credit: [[c:user:Idnan007|Idnan007]].{{tlx|free media}}]] "A plasma with local magnetohydrodynamic instabilities creates mechanical turbulence, motion, or shear (a dynamo) which in turn generates or sustains the local magnetic field."<ref name=RadiativeDynamo>{{ cite web |title=Radiative dynamo |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=June 30, 2012 |url=http://en.wikiversity.org/wiki/Radiative_dynamo |accessdate=2012-07-06 }}</ref> This prediction in the image on the right<ref name=Bhowmik>“Prediction of the strength and timing of sunspot cycle 25 reveal decadal-scale space environmental conditions”, Bhowmik, P., and Nandy, D. 2018, Nature Communications, 9, 5209 (https://www.nature.com/articles/s41467-018-07690-0)</ref> indicates that solar cycle 25 would be a weak, but not insignificant cycle. The ensemble prediction ranges from a cycle slightly weaker to slightly stronger compared to solar cycle 24. {{clear}} ==Electromagnetics== {{main|Radiation astronomy/Electromagnetics}} [[Image:Latest xrt soft x-ray.gif|thumb|right|250px|The Sun in the soft X-rays is seen by the Hinode X-ray Telescope (XRT) on October 15, 2009. Credit: Joseph B. Gurman, Facility Scientist, Solar Data Analysis Center, ISAS/JAXA and NASA.{{tlx|free media}}]] "The first systematic attempt to base a theory of the origin of the solar system on electromagnetic or hydromagnetic effects was made in Alfvén (1942). The reason for doing so was that a basic difficulty with the old Laplacian hypothesis: how can a central body (Sun or planet) transfer angular momentum to the secondary bodies (planets or satellites) orbiting around it? It was demonstrated that this could be done by electromagnetic effects. No other acceptable mechanism has yet been worked out. [...] the electromagnetic transfer mechanism has been confirmed by observations, as described in the monograph ''Cosmic Plasma'' (Alfvén, 1981, pp. 28, 52, 53 0."<ref name=Alfven1981>{{ cite journal |author=Hannes Alfvén |title=The Voyager 1/Saturn Encounter and the Cosmogonic Shadow Effect |journal=Astrophysics and Space Science |month=October |year=1981 |volume=79 |issue=2 |pages=491-505 |url=http://adsabs.harvard.edu/abs/1981Ap&SS..79..491A |arxiv= |bibcode=1981Ap&SS..79..491A |doi=10.1007/BF00649444 |pmid= |accessdate=2013-12-19 }}</ref> "If charged particles (electrons, ions or charged grains) move in a magnetic dipole field - strong enough to dominate their motion - under the action of gravitation and the centrifugal force, they will find an equilibrium in a circular orbit if their centrifugal force is 2/3 of the gravitational force [...] The consequence of this is that if they become neutralized, so that electromagnetic forces disappear, the centrifugal force is too small to balance the gravitation. Their circular orbit changes to an elliptical orbit with the semi-major axis ''a'' = 3/4''a''₀ and ''e'' = 1/3 (where ''a''₀ is the central distance where the neutralization takes place [...] Collisional (viscous) interaction between the condensed particles will eventually change the orbit into a new circular orbit with ''a'' = 2/3''a''₀ and ''e'' = 0."<ref name=Alfven1981/> "If [...] there is plasma in the region [collisional interaction results in] matter in the 2/3-[region]. [...] matter in the region [...] will produce a [cosmogonic] ''shadow'' in the region".<ref name=Alfven1981/> On the right is a soft X-ray image in the titanium-polyimide ("Ti_poly") filter from the Hinode X-Ray Telescope (XRT) obtained at: 2009/10/15 18:03 UTC. "The primary filter for the sigmoid observations was the “thin-aluminum/polyimide” (or “Al/poly”) filter, imaging plasmas with temperature of roughly 2–5 MK in the active region."<ref name=McKenzie>{{ cite journal |author=D. E. McKenzie and R. C. Canfield |title=Hinode XRT observations of a long-lasting coronal sigmoid |journal=Astronomy & Astrophysics |month= |year=2008 |volume=481 |issue= |pages=L65–L68 |url=http://www.aanda.org/articles/aa/pdf/2008/13/aa9035-07.pdf |arxiv= |bibcode= |doi=10.1051/0004-6361:20079035 |pmid= |accessdate=2016-11-03 }}</ref> {{clear}} ==Electron winds== As of December 5, 2011, "Voyager 1 is about ... 18 billion kilometers ... from the [S]un [but] the direction of the magnetic field lines has not changed, indicating Voyager is still within the heliosphere ... the outward speed of the solar wind had diminished to zero in April 2010 ... inward pressure from interstellar space is compacting [the magnetic field] ... Voyager has detected a 100-fold increase in the intensity of high-energy electrons from elsewhere in the galaxy diffusing into our solar system from outside ... [while] the [solar] wind even blows back at us."<ref name=Cole>{{ cite web |author=Steve Cole |author2=Jia-Rui C. Cook |author3=Alan Buis |title=NASA's Voyager Hits New Region at Solar System Edge |publisher=NASA |location=Washington, DC |date=December 2011 |url=http://www.nasa.gov/home/hqnews/2011/dec/HQ_11-402_AGU_Voyager.html |accessdate=2012-02-09 }}</ref> ==Flares== [[Image:06 Major Solar Flare (2820012601).jpg|thumb|right|250px|The solar flare shown in this image was captured on December 13, 2006. Credit: [https://www.flickr.com/people/11304375@N07 Image Editor].{{tlx|free media}}]] "[A] medium-strength flare erupted from the sun on July 19, 2012. The blast also generated the enormous, shimmering plasma loops, which are an example of a phenomenon known as "coronal rain," agency officials said."<ref name=WallRain>{{ cite book |author=Mike Wall |title=Super-Hot Plasma 'Rain' Falls on Sun in Amazing Video |publisher=Yahoo! News |location= |date=February 21, 2013 |url=http://news.yahoo.com/super-hot-plasma-rain-falls-sun-amazing-video-190147271.html |accessdate=2013-02-23 }}</ref> "The ... solar proton flare on 20 April 1998 at W 90° and S 43° (9:38 UT) was measured by the GOES-9-satellite (Solar Geophysical Data 1998), as well as by other experiments on WIND ... and GEOTAIL. Protons were accelerated up to energies > 110 MeV and are therefore able to hit the surface of Mercury."<ref name="Kirsch">{{cite book |author=E. Kirsch |author2=U.A. Mall |author3=B. Wilken |author4=G. Gloeckler |author5=A.B. Galvin |author6=K. Cierpka |title=Detection of Pickup- and Sputter Ions by Experiment SMS on the WIND-S/C After a Mercury Conjunction, In: ''Proceedings of the 26th International Cosmic Ray Conference'' |publisher=International Union of Pure and Applied Physics (IUPAP) |location=Salt Lake City, Utah, USA |date=August 17, 1999 |editor=D. Kieda |editor2=M. Salamon |editor3=B. Dingus |pages=212-5 |url= |arxiv= |bibcode=1999ICRC....6..212K |doi= |pmid= |isbn= }}</ref> Hinode's Solar Optical Telescope (SOT) provides crystal-clear images of features on the sun's surface. This image on the right shows a whirl of a new developing sunspot colliding with an existing spot that explodes into a major solar flare. The solar flare shown was captured on December 13, 2006. The flare produced high-energy protons that reached the Earth at the time of STS-116 Space Shuttle flight. The flare is shown in 3 different wavelengths. {{clear}} ==Flare stars== [[Image:ADLeoLightCurve.png|thumb|right|250px|U, B, V and R band light curves are for a flare on AD Leonis, adapted from Hawley and Pettersen, The Astrophysical Journal, vol 378, pp 725-741, 1991. Credit: [[c:user:PopePompus|PopePompus]].{{tlx|free media}}]] "Flare stars are intrinsically faint, but have been found to distances of 1,000 [[w:light year|light year]]s from Earth.<ref name=Kulkarni>{{ cite journal |author=Kulkarni SR, Rau A |year=2006 |bibcode=2006ApJ...644L..63K |title=The Nature of the Deep Lens Survey Fast Transients |journal=The Astrophysical Journal |doi=10.1086/505423 |volume=644 |issue=1 |pages=L63 |arxiv = astro-ph/0604343 }}</ref> {{clear}} ==Galactic coronas== Although a galactic corona is usually "filled with high-temperature plasma at temperatures of T ≈ 1–2 (MK), ... [h]ot active regions and postflare loops have plasma temperatures of T ≈ 2–40 MK."<ref name=Aschwanden2007>{{ cite journal |author=Markus J. Aschwanden |title=Fundamental Physical Processes in Coronae: Waves, Turbulence, Reconnection, and Particle Acceleration In: ''Waves & Oscillations in the Solar Atmosphere: Heating and Magneto-Seismology'' |journal=Proceedings IAU Symposium |year=2007 |editor=Erdelyi R |volume=3 |issue= S247 |pages=257–68 |arxiv=0711.0007 |url=http://journals.cambridge.org/download.php?file=%2FIAU%2FIAU3_S247%2FS1743921308014956a.pdf&code=7c95b408db74ccbe9f1f376d4cb1ef35 |doi=10.1017/S1743921308014956 }}</ref> "Discussion of the alternative hypothesis of cloud ejection from the equatorial layer of the Galaxy leads to the conclusion that the gaseous halo must be highly turbulent and that the coronal clouds are probably [[w:H I region|H I region]]s".<ref name=Grzedzielski>{{ cite journal |author=Grzędzielski, S. |author2=Stępień, K. |title=On the Cloudy Structure of the Galactic Gaseous Corona |journal=Acta Astronomica |year=1963 |volume=13 |issue= |pages=143-56 |url= |bibcode=1963AcA....13..143G |doi= |pmid= |accessdate=2011-08-01 }}</ref> "One question posed by these previous observations is where the absorption originates. If a coronal cloud, the cloud is more than 15 kpc from the plane of NGC 3067. This distance is greater than the optical radius of the galaxy, 9.6 kpc (''H'' = 50 km s^-1 Mpc^-1. Furthermore, the narrow line requires that the cloud be cool, in contrast to the wide range of ionization stages detected for the corona of our Galaxy (Savage and deBoer 1981)."<ref name=Rubin>{{ cite journal |author=Rubin V. C. |author2=Thonnard N. T. |author3=Ford W. K. Jr. |title=NGC 3067 - Additional evidence for nonluminous matter |journal=Astronomical Journal |month=March |year=1982 |volume=87 |issue=3 |pages=477-85 |url= |bibcode=1982AJ.....87..477R |doi=10.1086/113120 |pmid= |accessdate=2011-08-01 }}</ref> "But if the cloud originates instead in the disk, and is moving in a circular orbit viewed at an inclination of 68 deg (the inclination of the optical galaxy), then some gas extends at least to 40 kpc, which is over four times the optical radius."<ref name=Rubin/> ==Helmet streamers== [[Image:Helmet streamers at max.gif|thumb|right|250px|An abundance of helmet streamers is shown at solar maximum. Credit: NASA.{{tlx|free media}}]] [[Image:Helmet streamers at min.jpg|thumb|left|250px|Helmet streamers are shown at solar minimum restricted to mid latitudes. Credit: NASA.{{tlx|free media}}]] '''Helmet streamers''' are bright loop-like structures which develop over active regions on the [[Stars/Sun|sun]]. They are closed magnetic loops which connect regions of opposite magnetic polarity. Electrons are captured in these loops, and cause them to glow very brightly. The solar wind elongates these loops to pointy tips. They far extend above most prominences into the [[Coronal cloud|corona]], and can be readily observed during a solar eclipse. Helmet streamers are usually confined to the "streamer belt" in the mid latitudes, and their distribution follows the movement of active regions during the [[w:solar cycle|solar cycle]]. Small blobs of plasma, or "plasmoids" are sometimes released from the tips of helmet streamers, and this is one source of the slow component of the [[w:solar wind|solar wind]]. In contrast, formations with open magnetic field lines are called [[w:coronal holes|coronal holes]], and these are darker and are a source of the fast solar wind. Helmet streamers can also create coronal mass ejections if a large volume of plasma becomes disconnected near the tip of the streamer. {{clear}} ==Ionospheres== [[Image:Ionosphere-Thermosphere Processes.jpg|thumb|right|250px|In this diagram, the prominent features in the ionosphere-thermosphere system and their coupling to the different energy inputs show the complex temporal and spatial phenomena that are generated. Credit: NASA.{{tlx|free media}}]] Upon reaching the top of the [[w:Mesosphere|mesosphere]], the temperature starts to rise, but air pressure continues to fall. This is the beginning of the [[w:ionosphere|ionosphere]], a region dominated by chemical ions. Many of them are the same chemicals such as [[w:nitrogen|nitrogen]] and [[w:oxygen|oxygen]] in the atmosphere below, but an ever increasing number are hydrogen ions ([[w:proton|proton]]s) and helium ions. These can be detected by an ion spectrometer. The process of [[w:ionization|ionization]] removes one or more [[w:electron|electron]]s from a neutral atom to yield a variety of ions depending on the chemical element species and incidence of sufficient energy to remove the electrons. '''Def.''' the "part of the Earth's atmosphere beginning at an altitude of about 50 kilometers [31 miles] and extending outward 500 kilometers [310 miles] or more"<ref name=IonosphereWikt>{{ cite web |author=[[wikt:User:CORNELIUSSEON|CORNELIUSSEON]] |title=ionosphere |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=11 June 2006 |url=https://en.wiktionary.org/wiki/ionosphere |accessdate=2012-09-20 }}</ref> or the "similar region of the atmosphere of another planet"<ref name=IonosphereWikt1>{{ cite web |author=[[wikt:User:RJFJR|RJFJR]] |title=ionosphere |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=15 November 2008 |url=https://en.wiktionary.org/wiki/ionosphere |accessdate=2012-09-20 }}</ref> is called an '''ionosphere'''. "As a spacecraft travels through the solar system, a targeted radio signal sent back to Earth can be aimed through the ionosphere of a nearby planet. Plasma in the ionosphere causes small but detectable changes in the signal that allow scientists to learn about the upper atmosphere."<ref name=Redd>{{ cite web |author=Nola Taylor Redd |title=Meteoroids Change Atmospheres of Earth, Mars, Venus |publisher=Space.com |location= |date=September 4, 2012 |url=http://www.space.com/17440-meteoroids-mars-venus-atmospheres.html |accessdate=2012-09-05 }}</ref> {{clear}} ==Io plasma torus== {{main|Plasmas/Plasma objects/Io}} [[Image:Jupiter magnetosphere schematic.jpg|thumb|right|250px|This is a schematic of Jupiter's magnetosphere and the components influenced by Io (near the center of the image). Credit: John Spencer.{{tlx|free media}}]] The image at right represents "[t]he Jovian magnetosphere [magnetic field lines in blue], including the Io flux tube [in green], Jovian aurorae, the sodium cloud [in yellow], and sulfur torus [in red]."<ref name=Spencer>{{ cite book |author=John Spencer |title=John Spencer's Astronomical Visualizations |publisher=University of Colorado |location=Boulder, Colorado USA |date=November 2000 |url=http://www.boulder.swri.edu/~spencer/digipics.html |accessdate=2013-04-05 }}</ref> "Io may be considered to be a unipolar generator which develops an emf [electromotive force] of 7 x 10⁵ volts across its radial diameter (as seen from a coordinate frame fixed to Jupiter)."<ref name=Goldreich>{{ cite journal |author=Peter Goldreich |author2=Donald Lynden-Bell |title=Io, a jovian unipolar inductor |journal=The Astrophysical Journal |month=April |year=1969 |volume=156 |issue=04 |pages=59-78 |url= |arxiv= |bibcode=1969ApJ...156...59G |doi=10.1086/149947 |pmid= |accessdate=2013-04-05 }}</ref> "This voltage difference is transmitted along the magnetic flux tube which passes through Io. ... The current [in the flux tube] must be carried by keV electrons which are electrostatically accelerated at Io and at the top of Jupiter's ionosphere."<ref name=Goldreich/> "Io's high density (4.1 g cm^-3) suggests a silicate composition. A reasonable guess for its electrical conductivity might be the conductivity of the Earth's upper mantle, 5 x 10^-5 ohm^-1 cm^-1 (Bullard 1967)."<ref name=Goldreich/> As "a conducting body [transverses] a magnetic field [it] produces an induced electric field. ... The Jupiter-Io system ... operates as a unipolar inductor" ... Such unipolar inductors may be driven by electrical power, develop hotspots, and the "source of heating [may be] sufficient to account for the observed X-ray luminosity".<ref name=Wu>{{ cite journal |author=Kinwah Wu |author2=Mark Cropper |author3=Gavin Ramsay |author4=Kazuhiro Sekiguchi |title=An electrically powered binary star? |journal=Monthly Notices of the Royal Astronomical Society |month=March |year=2002 |volume=321 |issue=1 |pages=221-7 |url= |arxiv=astro-ph/0111358 |bibcode=2002MNRAS.331..221W |doi=10.1046/j.1365-8711.2002.05190.x |pmid= |accessdate=2013-04-05 }}</ref> "The electrical surroundings of Io provide another energy source which has been estimated to be comparable with that of the [gravitational] tides (7). A current of 5 x 10⁶ A is ... shunted across flux tubes of the Jovian field by the presence of Io (7-9)."<ref name=Gold>{{ cite journal |author=Thomas Gold |title=Electrical Origin of the Outbursts on Io |journal=Science |month=November |year=1979 |volume=206 |issue=4422 |pages=1071-3 |url= |arxiv= |bibcode=1979Sci...206.1071G |doi=10.1126/science.206.4422.1071 |pmid= |accessdate=2013-04-05 }}</ref> "[W]hen the currents [through Io] are large enough to cause ohmic heating ... currents ... contract down to narrow paths which can be kept hot, and along which the conductivity is high. Tidal heating [ensures] that the interior of Io has a very low eletrical resistance, causing a negligible extra amount of heat to be deposited by this current. ... [T]he outermost layers, kept cool by radiation into space [present] a large resistance and [result in] a concentration of the current into hotspots ... rock resistivity [and] contact resistance ... contribute to generate high temperatures on the surface. [These are the] conditions of electric arcs [that can produce] temperatures up to ionization levels ... several thousand kelvins".<ref name=Gold/> "[T]he outbursts ... seen [on the surface may also be] the result of the large current ... flowing in and out of the domain of Io ... Most current spots are likely to be volcanic calderas, either provided by tectonic events within Io or generated by the current heating itself. ... [A]s in any electric arc, very high temperatures are generated, and the locally evaporated materials ... are ... turned into gas hot enough to expand at a speed of 1 km/s."<ref name=Gold/> {{clear}} ==Local hot bubbles== [[Image:Local_bubble.jpg|thumb|right|250px|The Local Hot Bubble is hot X-ray emitting gas within the Local Bubble pictured as an artist's impression. Credit: NASA.{{tlx|free media}}]] The 'local hot bubble' is a "hot X-ray emitting plasma within the local environment of the Sun."<ref name=Kappes>{{ cite journal |author=M. Kappes |author2=J. Kerp |author3=P. Richter |title=The composition of the interstellar medium towards the Lockman Hole H I, UV and X-ray observations |journal=Astronomy and Astrophysics |month=July |year=2003 |volume=405 |issue=7 |pages=607-16 |url= |arxiv= |bibcode=2003A&A...405..607K |doi=10.1051/0004-6361:20030610 |pmid= |accessdate=2012-01-19 }}</ref> "This coronal gas fills the irregularly shaped local void of matter (McCammon & Sanders 1990) - frequently called the Local Hot Bubble (LHB)."<ref name=Kappes/> "The [X-ray] intensity of the [Local Hot Bubble] LHB varies across the entire sky:"<ref name=Kerp>{{ cite journal |author=J. Kerp |author2=W. B. Burton |author3=R. Egger |author4=M.J. Freyberg |author5=Dap Hartmann |author6=P.M.W. Kalberla |author7=U. Mebold |author8=J. Pietz |title=A search for soft X-ray emission associated with prominent high-velocity-cloud complexes |journal=Astronomy and Astrophysics |month=February |year=1999 |volume=342 |issue=02 |pages=213-32 |url=http://arxiv.org/abs/astro-ph/9810307 |arxiv=astro-ph/9810307 |bibcode=1999A&A...342..213K |doi= |pmid= |accessdate=2013-07-11 }}</ref> : ''I''_LHB = (2.5-8.2) x 10^-4 cts s^-1 arcmin^-2 (Snowden et al. 1998). The galactic X-ray background is produced largely by emission from the Local Hot Bubble which is within 100 parsecs of the Sun. The Local Hot Bubble is within the [[w:Local Bubble|Local Bubble]]. {{clear}} ==Magnetic clouds== A '''magnetic cloud''' is a transient event observed in the [[w:solar wind|solar wind]]. It was defined in 1981 by Burlaga et al. 1981 as a region of enhanced [[w:magnetic field|magnetic field]] strength, smooth rotation of the magnetic field vector and low [[w:proton|proton]] temperature <ref name=Burlaga>Burlaga, L. F., E. Sittler, F. Mariani, and R. Schwenn, "Magnetic loop behind an interplanetary shock: Voyager, Helios and IMP-8 observations" in "Journal of Geophysical Research", 86, 6673, 1981</ref>. Magnetic clouds are a possible manifestation of a [[w:Coronal Mass Ejection|Coronal Mass Ejection]] (CME). The association between CMEs and magnetic clouds was made by Burlaga et al. in 1982 when a magnetic cloud was observed by [[w:Helios probes|Helios-1]] two days after being observed by [[w:Solar Maximum Mission|SMM]]<ref name=Burlaga82>Burlaga, L. F. et al., "A magnetic cloud and a coronal mass ejection" in "Geophysical Research Letter"s, 9, 1317-1320, 1982</ref>. However, because observations near Earth are usually done by a single spacecraft, many CMEs are not seen as being associated with magnetic clouds. The typical structure observed for a fast CME by a satellite such as [[w:Advanced Composition Explorer|ACE]] is a fast-mode [[w:shock wave|shock wave]] followed by a dense (and hot) sheath of plasma (the downstream region of the shock) and a magnetic cloud. Other signatures of magnetic clouds are now used in addition to the one described above: among other, bidirectional superthermal electrons, unusual charge state or abundance of iron, helium, carbon and/or oxygen. The typical time for a magnetic cloud to move past a satellite at the [[w:Lagrange Point|L1]] point is 1 day corresponding to a radius of 0.15 [[w:Astronomical Unit|AU]] with a typical speed of 450&nbsp;km s⁻¹ and magnetic field strength of 20 nT.<ref name=Lepping>Lepping, R. P. et al. "Magnetic field structure of interplanetary magnetic clouds at 1 AU" in "Journal of Geophysical Research", 95, 11957-11965, 1990.</ref> ==Magnetic reconnections== Magnetic reconnection is a physical process in highly conducting plasmas in which the magnetic [[w:topology|topology]] is rearranged and magnetic energy is converted to [[w:kinetic energy|kinetic energy]], [[w:thermal energy|thermal energy]], and [[w:particle acceleration|particle acceleration]]. Magnetic reconnection occurs on timescales intermediate between slow resistive diffusion of the [[w:magnetic field|magnetic field]] and fast [[w:Alfven wave|Alfvénic]] timescales. The qualitative description of the reconnection process is such that magnetic field lines from different [[w:magnetic domain|magnetic domain]]s (defined by the field line connectivity) are spliced to one another, changing their patterns of connectivity with respect to the sources. It is a violation of an approximate conservation law in plasma physics, and can concentrate mechanical or magnetic energy in both space and time. ==Magnetospheres== [[Image:Structure of the magnetosphere LanguageSwitch.svg|thumb|right|250px|Diagram describes the components of the Earth's magnetosphere. Credit: NASA, [[w:User:Akaase|Aaron Kaase]] and [[c:user:Medium69|Medium69]].{{tlx|free media}}]] A '''magnetosphere''' is formed when a stream of charged particles, such as the solar wind, interacts with and is deflected by the magnetic field of a planet or similar body. “Planets which generate magnetic fields in their interiors ... are surrounded by invisible magnetospheres. ... [I]n many respects, the magnetosphere of Venus is a scaled-down version of Earth’s. ... Earth’s magnetosphere is 10 times larger [than that of Venus]”<ref name=Zhang>{{ cite book |author=Tielong Zhang |author2=Håkan Svedhem |title=A magnetic surprise for Venus Express |publisher=European Space Agency |location=The Netherlands |date=April 5, 2012 |url=http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=50246 |accessdate=2012-04-07 }}</ref> {{clear}} ==Microflares== Ultraviolet telescopes such as TRACE and the Solar and Heliospheric Observatory (SOHO)/EIT can observe individual [solar] micro-flares as small brightenings in extreme ultraviolet light.<ref name=Patsourakos>{{ cite journal | doi = 10.1051/0004-6361:20020151 | author =S. Patsourakos, J.-C. Vial | title = Intermittent behavior in the transition region and the low corona of the quiet Sun | journal = Astronomy and Astrophysics | volume = 385 | pages = 1073–1077 | year = 2002 | bibcode=2002A&A...385.1073P }}</ref> ==Nanoflares== [[Image:378877main Nanoflares lg.jpg|thumb|right|250px|"This false-color temperature map shows solar active region AR10923, observed close to center of the sun's disk. Blue regions indicate plasma near 10 million degrees K." Credit: Reale, et al. (2009), NASA.{{tlx|free media}}]] The image at the right shows the first detection of high temperature nanoflares. The false-color temperature map of solar active region AR10923, observed close to center of the sun's disk, contains nanoflare regions (blue, indicating plasma near 10 million degrees K). "Nanoflares are small, sudden bursts of heat and energy. "They occur within tiny strands that are bundled together to form a magnetic tube called a coronal loop," says Klimchuk. Coronal loops are the fundamental building blocks of the thin, translucent gas known as the sun's [[Coronal cloud|corona]]. ... Observations from the NASA-funded X-Ray Telescope (XRT) and Extreme-ultraviolet Imaging Spectrometer (EIS) instruments aboard Hinode reveal that ultra-hot plasma is widespread in solar active regions. The XRT measured plasma at 10 million degrees K, and the EIS measured plasma at 5 million degrees K. "These temperatures can only be produced by impulsive energy bursts,"says Klimchuk ... "Coronal loops are bundles of unresolved strands that are heated by storms of nanoflares." ... when a nanoflare suddenly releases its energy, the plasma in the low-temperature, low-density strands becomes very hot—around 10 million degrees K—very quickly. The density remains low, however, so the emission, or brightness, remains faint. Heat flows from up in the strand, where it's hot, down to the base of the coronal loop, where it's not as hot. This heats up the dense plasma at the loop’s base. Because it is so dense at the base, the temperature only reaches about 1 million degrees K. This dense plasma expands up into the strand. Thus, a coronal loop is a collection of 5-10 million degree K faint strands and 1 million degree K bright strands. "What we see is 1 million degree K plasma that has received its energy from the heat flowing down from the superhot plasma," says Klimchuk. "For the first time, we have detected this 10 million degree plasma, which can only be produced by the impulsive energy bursts of nanoflares.""<ref name=Layton2009>{{ cite web |author=Laura Layton |title=Tiny Flares Responsible for Outsized Heat of Sun's Atmosphere |publisher=NASA GSFC |location=Greenbelt, Maryland, USA |date=August 14, 2009 |url=http://www.nasa.gov/topics/solarsystem/features/nanoflares.html |accessdate=2012-11-18 }}</ref> The idea that nanoflares might heat the corona was put forward by [[w:Eugene Parker|Eugene Parker]] in the 1980s but is still controversial. In particular, ultraviolet telescopes such as [[w:TRACE|TRACE]] and [[w:Solar and Heliospheric Observatory|SOHO]]/EIT can observe individual micro-flares as small brightenings in extreme ultraviolet light,<ref name=Patsourakos/> but there seem to be too few of these small events to account for the energy released into the corona. The additional energy not accounted for could be made up by wave energy, or by gradual magnetic reconnection that releases energy more smoothly than micro-flares and therefore doesn't appear well in the TRACE data. Variations on the micro-flare hypothesis use other mechanisms to stress the magnetic field or to release the energy, and are a subject of active research in 2005. A nanoflare is a very small [[w:solar flare|solar flare]] which happens in the [[w:corona|corona]], the external [[w:atmosphere|atmosphere]] of the [[Stars/Sun|Sun]]. Observations show that the [[w:solar magnetic field|solar magnetic field]], which is frozen into the motion of the [[w:Plasma (physics)|plasma]] opens into semicirculal structures in the corona. These [[w:coronal loops|coronal loops]], which can be seen in the EUV and X-ray images (see the figure on the left), confine very hot plasma, emitting as it were at a temperature of a few million degrees. Many flux tubes are stable for several days on the solar corona in the X-ray images, emitting at steady rate. However flickerings, brightenings, small explosions, bright points, flares and mass eruptions are observed very frequently, especially in [[w:stellar active region|active regions]]. These macroscopic signs of solar activity are considered by astrophysicists as the phenomenology related to events of relaxation of stressed magnetic fields, during which part of the coronal heating is released by current dissipation or [[w:Joule effect|Joule effect]]. These nanoflares might be very tiny flares, so close one to each other, both in time and in space, to heat the corona and to cause all the phenomena due to solar activity. The distribution of the number of flares observed in the hard X-rays is a function of the energy, following a power law with negative spectral index 1.8.<ref name=Datlowe>{{ cite journal | author = D.W. Datlowe |author2=M.J.Elean |author3=H.S. Hudson | title =OSO-7 observations of solar x-rays in the energy range 10?100 keV | journal = Solar Physics | volume = 39 | pages = 155 | year = 1974 | doi = 10.1007/BF00154978 | bibcode=1974SoPh...39..155D }}</ref><ref name=Lin>{{ cite journal |author=Lin R.P. |author2=Schwartz R.A. |author3=Kane S.R. |author4=Pelling R.M. |author5=Hurley K.C. | journal= The Astrophysical Journal | volume= 283 | pages= 421 |doi=10.1086/162321 |title=Solar hard X-ray microflares | bibcode=1984ApJ...283..421L }}</ref><ref name=Dennis>{{ cite journal |author=Brian R. Dennis | year= 1985 | journal= Solar Physics | volume= 100 | pages= 465 |doi=10.1007/BF00158441 |title=Solar hard X-ray bursts | bibcode=1985SoPh..100..465D }}</ref> <ref name=Porter>{{ cite journal | author=Porter J.G. |author2=Fontenla J.M. |author3=Simnett G.M. |journal= The Astrophysical Journal | volume= 438 |pages= 472 | doi=10.1086/175091 | title=Simultaneous ultraviolet and X-ray observations of solar microflares | bibcode=1995ApJ...438..472P }}</ref> If this distribution would have the same spectral index also at lower energies, flares, micro-flares and nanoflares might provide a considerable part of coronal heating. Actually a negative spectral index of the order of 2 is required in order to maintain the [[w:solar corona|solar corona]]. "[T]he importance of the magnetic field is recognized by all the scientists: there is a strict correspondence between the [[w:stellar active region|active regions]], where the irradiated flux is higher (especially in the X-rays), and the regions of intense magnetic field.<ref name=Poletto>{{ cite journal |author=Poletto G |author2=Vaiana GS |author3=Zombeck MV |author4=Krieger AS |author5=Timothy AF |title=A comparison of coronal X-ray structures of active regions with magnetic fields computed from photospheric observations |journal=Solar Physics |date=September 1975 |volume=44 |issue=9 |pages=83–99 |doi=10.1007/BF00156848 |bibcode=1975SoPh...44...83P }}</ref> More energy is released in turbulent regimes when nanoflares happen at much smaller scale-lengths, where non-linear effects are not negligible.<ref name=Rappazzo>{{ cite journal |author= Rappazzo, A. F. |author2=Velli, M. |author3=Einaudi, G. |author4=Dahlburg, R. B. |title=Nonlinear Dynamics of the Parker Scenario for Coronal Heating |journal=The Astrophysical Journal 2008 |volume=677 |issue= 2 |pages= 1348–1366 |bibcode=2008ApJ...677.1348R |doi= 10.1086/528786 }}</ref> In order to heat a region of very high [[w:X-ray|X-ray]] emission, over an area 1" x 1", a nanoflare of 10¹⁷ J should happen every 20 seconds, and 1000 nanoflares per second should occur in a large active region of 10⁵ x 10⁵ km². Flickerings, brightenings, small explosions, bright points, flares and mass eruptions are observed very frequently, especially in [[stellar active region|active regions]]. {{clear}} ==Nova-like stars== {{main|Stars/Nova-likes}} [[Image:V838 Monocerotis expansion.jpg|thumb|right|250px| Successive photos of V838 Monocerotis show the progress of a light echo. Credit: NASA, ESA, H.E. Bond (STScI) and The Hubble Heritage Team (STScI/AURA).{{tlx|free media}}]] The evolution of non-magnetic dwarf novae and nova-like stars can be different from the magnetic systems (polars and intermediate polars).<ref name=Ak/> Magnetic and non-magnetic systems display different kinematical properties since some flow velocities come from magnetically channeled plasma.<ref name=Ak>{{ cite journal |author=T Ak T |author2=S Bilir |author3=S Ak |author4=KB Coskunoglu |author5=Z Eker |title=The age of cataclysmic variables: a kinematic study |journal=New Astronomy |month=August |year=2010 |volume=15 |issue=6 |pages=491-508 |url=http://adsabs.harvard.edu/abs/2010NewA...15..491A |arxiv=0911.3651 |bibcode=2010NewA...15..491A |doi=10.1016/j.newast.2009.11.007 |pmid= |accessdate=2016-09-30 }}</ref> {{clear}} ==Photospheres== The solar photosphere is a "weakly ionized [''n''_i/(''n''_i + ''n''_a)] ~ 10^-4, relatively cold and dense plasma".<ref name=Khodachenko>{{ cite journal |author=M. L. Khodachenko |author2=V. V. Zaitsev |title=Formation of Intensive Magnetic Flux Tubes in a Converging Flow of Partially Ionized Solar Photospheric Plasma |journal=Astrophysics and Space Science |month=March 01, |year=2002 |volume=279 |issue=4 |pages=389-410 |url=http://link.springer.com/article/10.1023/A:1015162131331 |arxiv= |bibcode= |doi=10.1023/A:1015162131331 |pmid= |accessdate=2013-07-17 }}</ref> ==Plages== [[Image:Plage areas chatzistergos 2020.png|thumb|right|250px|Graph that shows how much area in the surface of the Sun is occupied by bright magnetic features called faculae/plage. Credit: Theodosios Chatzistergos.{{tlx|free media}}]] A '''plage''' is a bright region in the [[w:chromosphere|chromosphere]] of [a star], typically found in regions of the chromosphere near [starspots]. The plage regions map closely to the [[w:faculae|faculae]] in the photosphere below, but the latter have much smaller spatial scales. Accordingly plage occurs most visibly near a starspot region. "Plages are formed in the inner parts of flux loops emerging from below. ... In the early stages of active region growth the appearance of the group is symmetric, while a few days later the ''f'' spot may disappear, leaving an extensive plage."<ref name=Zirin1974>{{ cite book |author=H. Zirin |title=The Magnetic Structure of Plages, In: ''Chromospheric Fine Structure'' |publisher=International Astronomical Union |location=Dordrecht |year=1974 |editor=R. Grant Athay |pages=161-75 |url= |arxiv= |bibcode=1974IAUS...56..161Z |doi= |pmid= |isbn= }}</ref> "[M]ajor changes in active regions only take place in the following ways: # [starspot] formation and break up; # flux outflow from [starspots]; # new flux emergence; and # magnetic reconnection."<ref name=Zirin1974/> "In general there is no proper motion at all in the plage or the surrounding plagettes except for the latter two."<ref name=Zirin1974/> {{clear}} ==Plasma objects== {{main|Plasmas/Plasma objects|Plasma objects}} '''Plasma''' is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms (reduce or increase the number of electrons in them), thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions.<ref name=Luo>{{ cite journal |author=Q-Z Luo |author2=N. D'Angelo |author3=R. L. Merlino | year=1998 |title=Shock formation in a negative ion plasma |journal= |volume=5 |issue=8 |publisher=Department of Physics and Astronomy |url=http://www.physics.uiowa.edu/~rmerlino/nishocks.pdf |accessdate=2011-11-20}}</ref> For plasma to exist, ionization is necessary. The term "plasma density" by itself usually refers to the "electron density", that is, the number of free electrons per unit volume. The degree of ionization of a plasma is the proportion of atoms that have lost or gained electrons, and is controlled mostly by the temperature. Even a partially ionized gas in which as little as 1% of the particles are ionized can have the characteristics of a plasma (i.e., response to magnetic fields and high electrical conductivity). The degree of ionization, ''α'' is defined as ''α'' = ''n''_i/(''n''_i + ''n''_a) where ''n''_i is the number density of ions and ''n''_a is the number density of neutral atoms. The ''electron density'' is related to this by the average charge state <Z> of the ions through ''n''_e = <Z> ''n''_i where ''n''_e is the number density of electrons. "Plasma is the fourth state of matter, consisting of electrons, ions and neutral atoms, usually at temperatures above 10⁴ degrees Kelvin."<ref name=Birdsall>{{ cite book |author=CK Birdsall, A. Bruce Langdon |title=Plasma Physics via Computer Simulation |publisher=CRC Press |location=New York |date=1 October 2004 |editor= |pages=479 |url=http://books.google.com/books?hl=en&lr=&id=S2lqgDTm6a4C&oi=fnd&pg=PR13&ots=nOPXyqtDo8&sig=-kA8YfaX6nlfFnaW3CYkATh-QPg |arxiv= |bibcode= |doi= |pmid= |isbn=9780750310253 |accessdate=2011-12-17 }}</ref> "The sun and stars are plasmas; the earth's ionosphere, Van Allen belts, magnetosphere, etc., are all plasmas. Indeed, plasma makes up much of the known matter in the universe."<ref name=Birdsall/> ==Plasma rains== "Hot plasma in the corona cooled and condensed along strong magnetic fields in the region" slowly falling back to the solar surface as plasma "rain".<ref name=WallRain/> {{clear}} ==Prominences== [[Image:Sunflare skylab4 big.jpg|thumb|right|250px|A major eruptive prominence is imaged by Skylab in 1973. Credit: [http://www.ksc.nasa.gov/history/skylab/skylab.html Skylab], NASA.{{tlx|free media}}]] [[Image:Detached sola prominence.jpg|thumb|right|250px|This shows a detached Solar prominence. Credit: [https://sites.google.com/site/thebrockeninglory/ Brocken Inaglory].{{tlx|free media}}]] A '''prominence''' is a large, bright feature extending outward from [a star's] surface, often in a [[w:Coronal loops|loop]] shape. Prominences are anchored to [a star's] surface in the [[w:photosphere|photosphere]], and extend outwards into the [star's] [[Coronal cloud|corona]]. While the corona consists of extremely hot ionized gases, known as [[w:Plasma (physics)|plasma]], which [does] not emit much visible light, prominences contain much cooler plasma, similar in composition to that of the [[w:chromosphere|chromosphere]]. A prominence forms over timescales of about a day, and stable prominences may persist in the corona for several months. Some prominences break apart and give rise to [[w:coronal mass ejection|coronal mass ejection]]s. A typical prominence extends over many thousands of kilometers; the largest on record was estimated at over 800,000 kilometres (500,000 mi) long<ref name="univtoday">{{ cite book |url=http://www.universetoday.com/96649/huge-solar-filament-stretches-across-the-sun/ |title=Huge Solar Filament Stretches Across the Sun |author=Nancy Atkinson |work=Universe Today |date=August 6, 2012 |accessdate=August 11, 2012 }}</ref> – roughly the radius of the Sun. "When a prominence is viewed from a different perspective so that it is against the [star] instead of against space, it appears darker than the surrounding background. This formation is instead called a [stellar] filament.<ref name="univtoday" /> It is possible for a projection to be both a filament and a prominence. Some prominences are so powerful that they throw out matter from the [star] into space at speeds ranging from 600&nbsp;km/s to more than 1000&nbsp;km/s. Other prominences form huge loops or arching columns of glowing gases over [starspots] that can reach heights of hundreds of thousands of kilometres. Prominences may last for a few days or even for a few months.<ref>{{ cite book | url=http://solar.physics.montana.edu/ypop/Program/hfilament.html | title=About Filaments and Prominences | accessdate=2010-01-02 }}</ref> Flocculi (plural of flocculus) is another term for these filaments, and dark flocculi typically describes the appearance of [stellar] prominences when viewed against the [stellar] disk in certain wavelengths. {{clear}} ==Regions== {{main|Regions/Astronomy}} [[Image:LASCO C1 coronagraph of solar corona.png‎|right|thumb|250px|A picture of the solar corona is taken with the [[w:LASCO|LASCO]] C1 coronagraph. The image is color coded for the doppler shift of the FeXIV 530.8 nm line. Credit: NASA and NRL.{{tlx|fairuse}}]] The preflare solar material is observed "to be an elevated cloud of prominence-like material which is suddenly lit up by the onslaught of hard electrons accelerated in the flare; the acceleration may be inside or outside the cloud, and brightening is seen in other areas of the solar surface on the same magnetic field lines."<ref name=Zirin78>{{ cite journal |author=Harold Zirin |title=The L-alpha/H-alpha ratio in solar flares, quasars, and the chromosphere |journal=Astrophysical Journal |month=June |year=1978 |volume=222 |issue=6 |pages=L105-7 |url= |bibcode=1978ApJ...222L.105Z |doi= 10.1086/182702 |pmid= |accessdate=2011-08-01 }}</ref> "A hot coronal cloud at ''T'' ~ 10⁷ K is left behind, presumably evaporated from the original material."<ref name=Zirin78/> "[O]nce ionized, the gas is rapidly heated by Coulomb collisions to the coronal cloud temperature, but as this material peels off, a cooler hydrogen-emitting region is left."<ref name=Zirin78/> Regions which are not in [[w:coronal hole|coronal hole]]s are "called 'coronal cloud' regions after their appearance in photographs of the Sun taken in soft X-rays, which most dramatically show up coronal holes."<ref name=McWhirter>{{ cite journal |author=McWhirter R. W. P. |author2=Kopp R. A. |title=The energy balance in the solar atmosphere above coronal holes |journal=Royal Astronomical Society, Monthly Notices |month=September |year=1979 |volume=188 |issue=9 |pages=871-81 |url= |bibcode=1979MNRAS.188..871M |doi= |pmid= |accessdate=2011-08-01 }}</ref> These 'coronal cloud' regions are "in fact the majority of the solar surface."<ref name=McWhirter/> Lying at a level above the 10⁴ K isotherm, "the thermally conducted flux is negligible, and bounded by the magnetic surfaces between open field (coronal hole) and closed field (coronal cloud) regions."<ref name=McWhirter/> "[C]oronal cloud regions produce no solar wind," but "[s]ome of the input energy may pass out of the cloud regions into the region where the wind is accelerated, thereby contributing to this process."<ref name=McWhirter/> In the image at right the iron (Fe XIV) green line is followed by doppler imaging to show associated relative coronal plasma velocity towards (-7 km/s side) and away from (+7 km/s side) the large angle spectrometric coronagraph [[w:LASCO|LASCO]] satellite camera. {{clear}} ==Starquakes== [[Image:MoretonWaveAnimation200612.gif|thumb|right|250px|This is an animation of a Moreton wave which occurred on the Sun at December 6, 2006. Credit: National Solar Observatory (NSO)/AURA/NSF and USAF Research Laboratory. {{tlx|fairuse}}]] [[Image:Solar tsunami.jpg|thumb|250px|left|This image shows a solar tsunami on May 19, 2007. Credit: NASA/STEREO/EUVI consortium.{{tlx|fairuse}}]] "The phenomenon of flare induced sunquakes - waves in the photosphere - discovered by Kosovichev and Zharkova (1998) and now widely studied (e.g. Kosovichev 2006) should also result from the momentum impulse delivered by a cometary impact."<ref name=Brown>{{ cite journal |author=J.C. Brown |author2=H.E. Potts |author3=L.J. Porter |author4=G.le Chat |title=Mass Loss, Destruction and Detection of Sun-grazing & -impacting Cometary Nuclei |journal=Astronomy & Astrophysics |date=November 8, 2011 |volume=535 |issue= |pages=12 |url=http://www.aanda.org/articles/aa/abs/2011/11/aa15660-10/aa15660-10.html |arxiv= |bibcode= |doi=10.1051/0004-6361/201015660 |pmid= |pdf=http://arxiv.org/pdf/1107.1857.pdf |accessdate=2012-11-25 }}</ref> A '''Moreton wave''' is the [[w:chromosphere|chromospheric]] signature of a large-scale solar [[Coronal cloud|coronal]] [[w:shock wave|shock wave]]. Described as a kind of [[Stars/Sun|solar]] '[[w:tsunami|tsunami]]',<ref name="tphill09">{{ cite book |author=Tony Phillips |title=Monster Waves on the Sun are Real |url=http://science.nasa.gov/science-news/science-at-nasa/2009/24nov_solartsunami/ |publisher=NASA |accessdate=16 July 2010 |date=November 24, 2009 }}</ref> they are generated by solar flares<ref name=Moreton>{{ cite journal |author=G. E. Moreton |title=Hα Observations of Flare-Initiated Disturbances with Velocities ~1000 km/sec |journal=Astronomical Journal |volume=65 |issue= |pages=494 |year=1960 |doi=10.1086/108346 |bibcode=1960AJ.....65U.494M }}</ref><ref name=Moreton60>{{ cite journal |author=G. E. Moreton, H. E. Ramsey |title=Recent Observations of Dynamical Phenomena Associated with Solar Flares |journal=Publications of the Astronomical Society of the Pacific |volume=72 |issue=428 |pages=357 |year=1960 |doi=10.1086/127549 |bibcode=1960PASP...72..357M }}</ref><ref name=Athay61>{{ cite journal |author=R. Grant Athay, Gail E. Moreton |title=Impulsive Phenomena of the Solar Atmosphere. I. Some Optical Events Associated with Flares Showing Explosive Phase |journal=The Astrophysical Journal |year=1961 |volume=133 |issue= |pages=935 |doi=10.1086/147098 |bibcode=1961ApJ...133..935A }}</ref>. The 1995 launch of the [[w:Solar and Heliospheric Observatory|Solar and Heliospheric Observatory]] led to observation of coronal waves, which cause Moreton waves. (SOHO's [[w:Extreme ultraviolet Imaging Telescope|EIT]] instrument discovered another, different wave type called 'EIT waves'.)<ref name=Chen>{{ cite journal |url=http://solar.physics.montana.edu/nuggets/2002/020208/020208.html |title=Moreton waves and coronal waves |journal=The Astrophysical Journal |volume=572 |issue= |pages=L99–L102 |year=2002 |bibcode = 2002ApJ...572L..99C |doi = 10.1086/341486 |author=P. F. Chen |author2=S. T. Wu |author3=K. Shibata |author4=C. Fang }}</ref> The reality of Moreton waves (aka fast-mode [[w:Magnetohydrodynamics|MHD]] waves) has also been confirmed by the two [[w:STEREO|STEREO]] spacecraft. They observed a 100,000-km-high wave of hot plasma and magnetism, moving at 250&nbsp;km/second, in conjunction with a big coronal mass ejection in February 2009.<ref name=Atkins>{{ cite book |author=William Atkins |title=STEREO spacecraft finds gigantic tsunami on Sun |url=http://www.itwire.com/science-news/space/29658-stereo-spacecraft-finds-gigantic-tsunami-on-sun |publisher=iTWire |accessdate=16 July 2010 |date=26 November 2009 }}</ref><ref name="pho111909">{{ cite book |title=Mystery of the Solar Tsunami -- Solved |url=http://www.physorg.com/news177872248.html |publisher=PhysOrg.com |accessdate=16 July 2010 |author=JPL/NASA |date=November 19, 2009 }}</ref> Moreton waves propagate at a speed of usually 500–1500&nbsp;km/s. [[w:Yutaka Uchida|Yutaka Uchida]] interpreted Moreton waves as MHD fast mode shock waves propagating in the corona.<ref name=Sakurai2002>{{ cite book |author=Takashi Sakurai |title=SolarNews Newsletter |url=http://spd.aas.org/SolarNews/archive/news.2002/19.sep |publisher=Solar Physics Division, American Astronomical Society |accessdate=15 June 2011 |date=3 September 2002 }}</ref> He links them to [[w:type II radio bursts|type II radio bursts]], which are radio wave discharges created when coronal mass ejections accelerate shocks.<ref name=Layton>{{ cite book |author=Laura Layton |title=STEREO Spies First Major Activity of Solar Cycle 24 |url=http://www.nasa.gov/mission_pages/stereo/news/solarcycle24.html |publisher=NASA |accessdate=15 June 2011 |date=May 15, 2009 }}</ref> Moreton waves can be observed primarily in the [[w:Hα|Hα]] band.<ref name="Narukage, et al.">{{ cite journal |author=N. Narukage |author2=Shigeru |author3=Miwako Kadota |author4=Reizaburo Kitai |author5=Hiroki Kurokawa |author6=Kazunari Shibata |year=2004 |title=Moreton waves observed at Hida Observatory |journal = Proceedings IAU Symposium |issue = 223 |pages = 367–370 |doi=10.1017/S1743921304006143 |url=http://journals.cambridge.org/production/action/cjoGetFulltext?fulltextid=288483 |accessdate = 2006-12-11 |volume = 2004 }}</ref> {{clear}} ==Stellar cycles== [[Image:Sunspot_butterfly_graph.gif|thumb|200px|right|The butterfly diagram shows paired sunspot pattern. The graph is of sunspot Wolf number versus time. Credit: NASA, Marshal Space Flight Center, Solar Physics.{{tlx|free media}}]] The solar cycle has a great influence on [[w:space weather|space weather]], and a significant influence on the Earth's climate since the Sun's luminosity has a direct relationship with magnetic activity.<ref name=Wilson>{{ cite journal |author=R. C. Willson, H. S. Hudson |year=1991 |title=The Sun's luminosity over a complete solar cycle |journal=Nature |volume=351 |issue=6321 |pages=42–4 |doi=10.1038/351042a0 |bibcode = 1991Natur.351...42W }}</ref> Solar activity minima tend to be correlated with colder temperatures, and longer than average solar cycles tend to be correlated with hotter temperatures. In the 17th century, the solar cycle appeared to have stopped entirely for several decades; few sunspots were observed during this period. During this era, known as the [[w:Maunder minimum|Maunder minimum]] or [[w:Little Ice Age|Little Ice Age]], Europe experienced unusually cold temperatures.<ref name="Lean">{{ cite journal |last=Lean |first=J. |last2=Skumanich |first2=A. |last3=White |first3=O. |year=1992 |title=Estimating the Sun's radiative output during the Maunder Minimum |journal=Geophysical Research Letters |volume=19 |issue=15 |pages=1591–1594 |doi=10.1029/92GL01578 |ref=harv |bibcode=1992GeoRL..19.1591L }}</ref> Earlier extended minima have been discovered through analysis of [[w:tree ring|tree ring]]s and appear to have coincided with lower-than-average global temperatures.<ref name=Mackay>{{ cite book |author=R. M. Mackay, M. A. K. Khalil |title=Greenhouse gases and global warming, In: ''Trace Gas Emissions and Plants'' |url= http://books.google.com/?id=tQBS3bAX8fUC&pg=PA1 |editor=S. N. Singh |year=2000 |pages=1–28 |publisher=Springer |isbn=978-0-7923-6545-7 }}</ref> "MOST current literature on solar activity assumes that the planets do not affect it, and that conditions internal to the Sun are primarily responsible for the solar cycle. Bigg¹, however, has shown that the period of Mercury's orbit appears in the sunspot data, and that the influence of Mercury depends on the phases of Venus, Earth, and Jupiter."<ref name=Wood>{{ cite journal |author=K. D. Wood |title=Physical Sciences: Sunspots and Planets |journal=Nature |month=November 10, |year=1972 |volume=240 |issue=5376 |pages=91-3 |url=http://www.nature.com/nature/journal/v240/n5376/abs/240091a0.html |arxiv= |bibcode=1972Natur.240...91W |doi=10.1038/240091a0 |pmid= |accessdate=2013-07-07 }}</ref> "It is shown that starting with the alignment of Venus with Jupiter at perihelion position, these two planets will perfectly align at Jupiter's perihelion after every 23.7 years".<ref name=Verma>{{ cite book |author=S.D. Verma |title=Influence of Planetary Motion and Radial Alignment of Planets on Sun, In: ''Space Dynamics and Celestial Mechanics'' |publisher=Springer Netherlands |location= |year=1986 |editor=K. B. Bhatnagar |volume=127 |issue= |pages=143-54 |url=http://link.springer.com/chapter/10.1007/978-94-009-4732-0_13 |arxiv= |bibcode= |doi=10.1007/978-94-009-4732-0_13 |pmid= |isbn=978-94-010-8603-5 |accessdate=2013-07-07 }}</ref> "The tidal forces hypothesis for solar cycles has been proposed by Wood (1972) and others. Table 2 below shows the relative tidal forces of the planets on the sun. Jupiter, Venus, Earth and Mercury are called the "tidal planets" because they are the most significant. According to Wood, the especially good alignments of J-V-E with the sun which occur about every 11 years are the cause of the sunspot cycle. He has shown that the sunspot cycle is synchronous with the alignments, and J. Schove's data for 1500 year of sunspot maxima supports the 11.07 year J-V-E period average."<ref name=Tomes/> "Both the 11.86 year Jupiter tropical period (time between perihelion's or closest approaches to the sun and the 9.93 year J-S alignment periods are found in sunspot spectral analysis. Unfortunately direct calculations of the tidal forces of all planets does not support the occurrence of the dominant 11.07 year cycle. Instead, the 11.86 year period of Jupiter's perihelion dominates the results. This has caused problems for several researchers in this field."<ref name=Tomes>{{ cite journal |author=Ray Tomes |title=Towards a Unified Theory of Cycles |publisher=Cycles Research Institute |location= |month=February |year=1990 |editor= |volume= |issue= |pages=21 |url=http://cyclesresearchinstitute.org/cycles-general/tomes_unified_cycles.pdf |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2013-07-07 }}</ref> "[B]y assuming a harmonic variation having a period of 11.13 years ... the phases of such a variation [in polar diameter minus equatorial diameter of the Sun] coincide to within one-fifth of a year with the phases of the sun-spot fluctuations; that, at times corresponding to minimum of sun-spottedness, the polar diameter is relatively larger; that, at times of maximum sun-spottedness, the equatorial diameter is relatively larger. The amplitude of the variation is extremely small, but its reality would seem to be established. [This] at least renders the existence of such periodic fluctuations in the shape of the sun more probable than their non-existence."<ref name=Poor>{{ cite journal |author=Charles Lane Poor |title=An investigation of the figure of the Sun and of possible variations in its size and shape [Reprint of: Annals N.Y. Acad Sci., Vol XVIII, pp.385 - 424] |journal=Contributions from the Rutherford Observatory of Columbia University New York |month=August |year=1908 |volume=26 |issue=08 |pages=385-424 |url= |arxiv= |bibcode=1908CoRut..26..385P |doi= |pmid= |accessdate=2013-05-16 }}</ref> "Solar oblateness, the difference between the equatorial and polar diameters, reflects certain fundamental properties of the Sun. ... the oblateness reflects properties of the Sun's interior, ... [There is] a time varying, excess equatorial brightness [producing] a difference between the equatorial and polar limb darkening functions ... at times when the excess brightness is reduced, the intrinsic visual oblateness can be obtained from the observations without detailed knowledge of the excess brightness. A period of reduced excess brightness occurred in 1973 September."<ref name=Hill>{{ cite journal |author=H. A. Hill |author2=R. T. Stebbins |title=The intrinsic visual oblateness of the sun |journal=The Astrophysical Journal |month=September 1, |year=1975 |volume=200 |issue=09 |pages=471-5 |url= |arxiv= |bibcode=1975ApJ...200..471H |doi=10.1086/153813 |pmid= |accessdate=2013-05-16 }}</ref> The period of reduced excess equatorial brightness occurred between solar cycle maximum around 1970 and minimum around 1975. Considering excess equatorial brightness and seeking to perform measurements at opportunities of reduced excess equatorial brightness has the effect of reducing solar oblateness from some 86.6 ± 6.6 milli-arcsec to 18.4 ± 12.5 milli-arcsec.<ref name=Hill/> The Babcock Model describes a mechanism which can explain magnetic and sunspot patterns observed on the Sun: # The start of the 22-year cycle begins with a well-established dipole field component aligned along the solar rotational axis. The field lines tend to be held by the highly conductive solar plasma of the solar surface. # The solar surface plasma rotation rate is different at different latitudes, and the rotation rate is 20 percent faster at the equator than at the poles (one rotation every 27 days). Consequently, the magnetic field lines are wrapped by 20 percent every 27 days. # After many rotations, the field lines become highly twisted and bundled, increasing their intensity, and the resulting buoyancy lifts the bundle to the solar surface, forming a bipolar field that appears as two spots, being kinks in the field lines. # The sunspots result from the strong local magnetic fields in the solar surface that exclude the light-emitting solar plasma and appear as darkened spots on the solar surface. # The leading spot of the bipolar field has the same polarity as the solar hemisphere, and the trailing spot is of opposite polarity. The leading spot of the bipolar field tends to migrate towards the equator, while the trailing spot of opposite polarity migrates towards the solar pole of the respective hemisphere with a resultant reduction of the solar dipole moment. This process of sunspot formation and migration continues until the solar dipole field reverses (after about 11 years). # The solar dipole field, through similar processes, reverses again at the end of the 22-year cycle. # The magnetic field of the spot at the equator sometimes weakens, allowing an influx of coronal plasma that increases the internal pressure and forms a magnetic bubble which may burst and produce an ejection of coronal mass, leaving a coronal hole with open field lines. Such a coronal mass ejections are a source of the high-speed solar wind. # The fluctuations in the bundled fields convert magnetic field energy into plasma heating, producing emission of electromagnetic radiation as intense ultraviolet (UV) and X-rays. {{clear}} ==Stellar winds== [[Image:SpaceEnvironmentOverview From 19830101.jpg|thumb|right|200px|This image shows an overview of the space weather conditions over several solar cycles including the relationship between sunspot numbers and cosmic rays. Credit: [[c:User:Daniel Wilkinson|Daniel Wilkinson]].{{tlx|free media}}]] "The '''solar wind''' is a stream of charged particles ejected from the upper atmosphere of the [[Sun (star)|Sun]]. It mostly consists of electrons and protons with energies usually between 1.5 and 10 [[w:electronvolt|keV]]. Δ''T''_''A'' may have values from "7-19 min for a small sample of well-connected ... cosmic-ray flares."<ref name="Cliver"/> The transit time anomaly may be explained by a rise time associated with the ground-level events (GLEs). "The average GLE rise time ... for well-connected ... events ... defined to be the time from event onset to maximum as measured by the neutron monitor station showing the largest increase and whose asymptotic cone of acceptance ... includes the nominal direction of the Archimedean spiral path, is 21.3 min."<ref name="Cliver"/> The solar wind originates through the polar coronal holes. "The solar wind is a plasma, composed primarily of electrons and lone protons, and the variations in the index of refraction are caused by variations in the density of the plasma.<ref>Jokipii (1973), pp. 11–12.</ref> Different indices of refraction result in phase changes between waves traveling through different locations, which results in interference. As the waves interfere, both the frequency of the wave and its angular size are broadened, and the intensity varies.<ref>Alurkar (1997), p. 11.</ref>"<ref name=McBride>{{ cite web |author=[[w:User:James McBride|James McBride]] |title=Interplanetary scintillation |publisher=Wikimedia Foundation, Inc |location=San Francisco, California |date=October 1, 2013 |url=https://en.wikipedia.org/wiki/Interplanetary_scintillation |accessdate=2014-01-23 }}</ref> ==Van Allen radiation belts== The '''Van Allen radiation belt''' is split into two distinct belts, with energetic electrons forming the outer belt and a combination of protons and electrons forming the inner belts. In addition, the radiation belts contain lesser amounts of other nuclei, such as [[w:alpha particle|alpha particle]]s. The trapped particle population of the outer belt is varied, containing electrons and various ions. Most of the ions are in the form of energetic protons, but a certain percentage are [[w:alpha particles|alpha particles]] and O⁺ oxygen ions, similar to those in the [[w:ionosphere|ionosphere]] but much more energetic. While protons form one radiation belt, trapped electrons present two distinct structures, the inner and outer belt. The inner electron Van Allen Belt extends typically from an altitude of 1.2 to 3 Earth radii (L values of 1 to 3).<ref name=Ganushkina>{{ cite journal | author=Ganushkina N.Y. |author2=I. Dandouras |author3=Y. Y. Shprits |author4=J. Cao | title=Locations of boundaries of outer and inner radiation belts as observed by Cluster and Double Star | journal=Journal of Geophysical Research | volume=116 |issue=A09234 |doi=10.1029/2010JA016376 | year=2011 | pages=1–18 |url=http://onlinelibrary.wiley.com/doi/10.1029/2010JA016376/abstract }}</ref> In certain cases when solar activity is stronger or in geographical areas such as the [[w:South Atlantic Anomaly|South Atlantic Anomaly]] (SAA), the inner boundary may go down to roughly 200 kilometers<ref>{{ cite book |title=ECSS Space engineering |date=15 November 2008 |url=https://www.scribd.com/document/122967505/ECSS-space-engineering }}</ref> above the Earth's surface. The inner belt contains high concentrations of electrons in the range of hundreds of keV and energetic protons with energies exceeding 100 MeV, trapped by the strong (relative to the outer belts) magnetic fields in the region.<ref name=Gusev>{{ cite journal | author=Gusev A.A. |author2=G.I. Pugacheva |author3=U.B. Jayanthi |author4=N. Schuch | title=Modeling of Low-altitude Quasi-trapped Proton Fluxes at the Equatorial Inner Magnetosphere | journal=Brazilian Journal of Physics | vol. 33 | no. 4 | year=2003 | pages=775–781 |url=http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-97332003000400029 }}</ref> It is believed that proton energies exceeding 50 MeV in the lower belts at lower altitudes are the result of the [[w:beta decay|beta decay]] of [[w:neutrons|neutrons]] created by cosmic ray collisions with nuclei of the upper atmosphere. The source of lower energy protons is believed to be proton diffusion due to changes in the magnetic field during geomagnetic storms.<ref name=Tascione>{{ cite book | first=Thomas F. | last=Tascione | title=Introduction to the Space Environment, 2nd. Ed. | publisher=Kreiger Publishing CO.| location=Malabar, Florida USA | year=1994 |url=http://astrobooks.com/introductiontothespaceenvironmentsecondeditionsoftbackthomasftascione-1994.aspx | isbn=0-89464-044-5}}</ref> Due to the slight offset of the belts from Earth's geometric center, the inner Van Allen belt makes its closest approach to the surface at the South Atlantic Anomaly.<ref name="Goddard">NASA Goddard Spaceflight Center, |url=http://image.gsfc.nasa.gov/poetry/tour/AAvan.html |title=The Van Allen Belts] (Accessed May 25, 2011)</ref><ref name=Underwood>{{ cite journal | author=Underwood, C. |author2=Brock, D. |author3=Williams, P. |author4=Kim, S. |author5=Dilão, R. |author6=Ribeiro Santos, P. |author7=Brito, M. |author8=Dyer, C. |author9=Sims, A. | title=Radiation Environment Measurements with the Cosmic Ray Experiments On-Board the KITSAT-1 and PoSAT-1 Micro-Satellites | journal=IEEE Transactions on Nuclear Sciences | volume=41 | year=1994 | pages=2353–2360 |url=http://ieeexplore.ieee.org/document/340587/ }}</ref> The proton belts contain [[w:protons|protons]] with kinetic energies ranging from about 100 keV (which can penetrate 0.6&nbsp;microns of lead) to over 400 MeV (which can penetrate 143&nbsp;mm of lead).<ref name=Hess>{{cite book |author=Wilmot N. Hess |title=The Radiation Belt and Magnetosphere |publisher=Blaisdell Pub. Co. |date=1968 |url=http://adsabs.harvard.edu/abs/1968rbm..book.....H }}</ref> The [[w:Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics|PAMELA]] experiment detected orders of magnitude higher levels of [[w:antiproton|antiproton]]s than are expected from normal [[w:particle decay|particle decay]]s while passing through the SAA. This suggests the van Allen belts confine a significant flux of antiprotons produced by the interaction of the Earth's upper atmosphere with [[w:cosmic rays|cosmic rays]].<ref name=Adriani>{{ cite journal | doi = 10.1088/2041-8205/737/2/L29 | title = The Discovery of Geomagnetically Trapped Cosmic-Ray Antiprotons | year = 2011 | last1 = Adriani | first1 = O. | last2 = Barbarino | first2 = G. C. | last3 = Bazilevskaya | first3 = G. A. | last4 = Bellotti | first4 = R. | last5 = Boezio | first5 = M. | last6 = Bogomolov | first6 = E. A. | last7 = Bongi | first7 = M. | last8 = Bonvicini | first8 = V. | last9 = Borisov | first9 = S. | journal = The Astrophysical Journal Letters | volume = 737 | issue = 2 | pages = L29 | bibcode = 2011ApJ...737L..29A | arxiv=1107.4882v1 }}</ref> The energy of the antiprotons has been measured in the range from 60 - 750 MeV. When cosmic-ray protons enter the Earth’s atmosphere they collide with molecules, mainly oxygen and nitrogen, to produce a cascade of billions of lighter particles, a so-called air shower. An air shower is an extensive (many kilometres wide) cascade of ionized particles and electromagnetic radiation produced in the atmosphere when a primary cosmic-ray proton (i.e. one of extraterrestrial origin) enters the atmosphere. During solar proton events, ionization can reach unusually high levels in the D-region over high and polar latitudes. Such very rare events are known as Polar Cap Absorption (or PCA) events, because the increased ionization significantly enhances the absorption of radio signals passing through the region. In fact, absorption levels can increase by many tens of dB during intense events, which is enough to absorb most (if not all) transpolar HF radio signal transmissions. Such events typically last less than 24 to 48 hours. Associated with solar flares is a release of high-energy protons. These particles can hit the Earth within 15 minutes to 2 hours of the solar flare. The protons spiral around and down the magnetic field lines of the Earth and penetrate into the atmosphere near the magnetic poles increasing the ionization of the D and E layers. PCA's typically last anywhere from about an hour to several days, with an average of around 24 to 36 hours. ==Cosmic rays== {{main|Radiation/Cosmic rays}} "A persistent problem of solar cosmic-ray research has been the lack of observations bearing on the timing and conditions in which protons that escape to the interplanetary medium are first accelerated in the corona."<ref name="Cliver">{{cite journal |author=E. W. Cliver |author2=S. W. Kahler |author3=M. A. Shea |author4=D. F. Smart |title=Injection onsets of ~2 GeV protons, ~1 MeV electrons, and ~100 keV electrons in solar cosmic ray flares |journal=The Astrophysical Journal |month=September 1 |year=1982 |volume=260 |issue=9 |pages=362-70 |url= |arxiv= |bibcode=1982ApJ...260..362C |doi= |pmid= |accessdate=2012-08-21 }}</ref> "For solar cosmic-rays, the apparent lack of proton acceleration in the corona seems justified, in contrast to the electrons, proton bremsstrahlung and gyrosynchrotron emission are negligible. This suggests a transit time anomaly, Δ''T''_''A'', defined as follows: : Δ''T''_''A'' = Δ''T''_onset - 11 min, where Δ''T''_onset is the deduced Sun-Earth transit time for the first arriving relativistic protons and 11 min is the nominal transit time for a ~2 GeV proton traversing a 1.3 AU Archimedes spiral path."<ref name="Cliver">{{cite journal |author=E. W. Cliver |author2=S. W. Kahler |author3=M. A. Shea |author4=D. F. Smart |title=Injection onsets of ~2 GeV protons, ~1 MeV electrons, and ~100 keV electrons in solar cosmic ray flares |journal=The Astrophysical Journal |month=September 1 |year=1982 |volume=260 |issue=9 |pages=362-70 |url= |arxiv= |bibcode=1982ApJ...260..362C |doi= |pmid= |accessdate=2012-08-21 }}</ref> ==Protons== {{main|Radiation astronomy/Protons|Proton astronomy}} [[Image:GOES protons.jpg|thumb|right|250px|This graph displays the flux of high energy protons measured by GOES 11 over four days from November 2, 2004, to November 4, 2003. Credit: NOAA.{{tlx|free media}}]] The Sun and the solar wind, at least that portion that originates through the polar coronal holes apparently from the photosphere, may be major sources of protons within the solar system. At right is a temporal distribution of solar proton flux in units of particles cm^-2 s^-1 sr^-1 as measured by GOES 11 over the four days from November 2, 2003, to November 4, 2003, in three windows of energy: ≥ 100 MeV (green), ≥ 50 MeV (blue), and ≥ 10 MeV (red). The percentage originating from the surface of the Sun either directly or through the contribution to the solar wind is not indicated. {{clear}} ==Electrons== {{main|Radiation astronomy/Electrons}} "The density of the coronal cloud deduced in this case is about 2 x 10¹¹ electrons per cubic centimeter."<ref name=Zinn1965>{{ cite book |author=H. Zinn |title=Solar Flares and Concurrent Phenomena in the Solar Atmosphere, In: ''Proceedings of the Plasma Space Science Symposium'' |publisher=Springer |location=Netherlands |year=1965 |editor=C. C. Chang |editor2=S. S. Huang |volume=3 |issue= |pages=38-51 |url=http://link.springer.com/chapter/10.1007/978-94-011-7542-5_5 |arxiv= |bibcode= |doi=10.1007/978-94-011-7542-5_5 |pmid= |isbn=978-94-011-7544-9 |accessdate=2013-07-07 }}</ref> ==Positrons== {{main|Radiation astronomy/Positrons}} [[Image:Rhessi0269 web.jpg|thumb|right|250px|RHESSI observes high-energy phenomena from a solar flare. Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio.{{tlx|free media}}]] The solar flare at Active Region 10039 on July 23, 2002, exhibits many exceptional high-energy phenomena including the 2.223 MeV neutron capture line and the 511 keV electron-positron (antimatter) annihilation line. In the image at right, the RHESSI low-energy channels (12-25 keV) are represented in red and appear predominantly in coronal loops. The high-energy flux appears as blue at the footpoints of the coronal loops. Violet is used to indicate the location and relative intensity of the 2.2 MeV emission. During solar flares “[s]everal radioactive nuclei that emit positrons are also produced; [which] slow down and annihilate in flight with the emission of two 511 keV photons or form positronium with the emission of either a three gamma continuum (each photon < 511 keV) or two 511 keV photons."<ref name=Share>{{ cite book |author=Gerald H. Share |author2=Ronald J. Murphy |title=Solar Gamma-Ray Line Spectroscopy – Physics of a Flaring Star, In: ''Stars as Suns: Activity, Evolution and Planets'' |publisher=Astronomical Society of the Pacific |location=San Francisco, CA |date=January 2004 |editor=Andrea K. Dupree, A. O. Benz |pages=133-44 |url=http://heseweb.nrl.navy.mil/gamma/solar/papers/share_iau_04.pdf |arxiv= |bibcode=2004IAUS..219..133S |doi= |pmid= |isbn=158381163X |accessdate=2012-03-15 }}</ref> The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) made the first high-resolution observation of the solar positron-electron annihilation line during the July 23, 2003 solar flare.<ref name=Share/> The observations are somewhat consistent with electron-positron annihilation in a quiet solar atmosphere via positronium as well as during flares.<ref name=Share/> Line-broadening is due to "the velocity of the positronium."<ref name=Share/> "The width of the annihilation line is also consistent ... with thermal broadening (Gaussian width of 8.1 ± 1.1 keV) in a plasma at 4-7 x 10⁵ K. ... The ''RHESSI'' and all but two of the ''SMM'' measurements are consistent with densities ≤ 10¹² H cm^-3 [but] <10% of the p and α interactions producing positrons occur at these low densities. ... positrons produced by ³He interactions form higher in the solar atmosphere ... all observations are consistent with densities > 10¹² H cm^-3. But such densities require formation of a substantial mass of atmosphere at transition region temperatures."<ref name=Share/> {{clear}} ==Neutrinos== {{main|Radiation astronomy/Neutrinos|Neutrino astronomy}} [[Image:Neusun1 superk1.jpg|thumb|right|250px|This "neutrino image" of the Sun is produced by using the Super-Kamiokande to detect the neutrinos from nuclear fusion coming from the Sun. Credit: R. Svoboda and K. Gordan (LSU).{{tlx|fairuse}}]] [[Image:Bahcall Figure 2.jpg|thumb|right|250px|This figure shows a detected 94 % correlation between scaled sunspot numbers and neutrino detections. Credit: John N. Bahcall.{{tlx|fairuse}}]] Neutrinos are hard to detect. The Super-Kamiokande, or "Super-K" is a large-scale experiment constructed in an unused mine in Japan to detect and study neutrinos. The image at right required 500 days worth of data to produce the "neutrino image" of the Sun. The image is centered on the Sun's calculated position. It covers a 90° x 90° octant of the sky (in right ascension and declination). The higher the brightness of the color, the larger is the neutrino flux. The surface of the Sun is not a known source of neutrinos. Those detected may be from nucleosynthesis within the coronal cloud in the near vicinity of the Sun or perhaps from nucleosynthesis occurring interior to the Sun. "[N]eutrino flux increases noted in Homestake results [coincide] with major solar flares [14]."<ref name=Dubin>{{ cite journal |author=Maurice Dubin |author2=Robert K. Soberman |title=Resolution of the Solar Neutrino Anomaly |journal=arXiv |date=April 1996 |volume= |issue= |pages=1-8 |url=http://arxiv.org/abs/astro-ph/9604074 |arxiv=astro-ph/9604074 |bibcode=1996astro.ph..4074D |doi= |pmid= |pdf=http://arxiv.org/pdf/astro-ph/9604074.pdf |accessdate=2012-11-11 }}</ref> This result together with those in the next two paragraphs establishes that neutrinos are being produced by processes above the photosphere and probably within 2-4 solar radii as most solar flares give off energy close to and into the chromosphere. "The correlation between a great solar flare and Homestake neutrino enhancement was tested in 1991. Six major flares occurred from May 25 to June 15 including the great June 4 flare associated with a coronal mass ejection and production of the strongest interplanetary shock wave ever recorded (later detected from spacecraft at 34, 35, 48, and 53 AU) [15]. It also caused the largest and most persistent (several months) signal ever detected by terrestrial cosmic ray neutron monitors in 30 years of operation [16]. The Homestake exposure (June 1–7) measured a mean ³⁷Ar production rate of 3.2 ± 1.5 atoms/day (≈19 ³⁷Ar atoms produced in 6 days) [13]; about 5 times the rate of ≈ 0.65 day ⁻¹ for the preceding and following runs, > 6 times the long term mean of ≈ 0.5 day⁻¹ and > 2 1/2 times the highest rates recorded in ∼ 25 operating years."<ref name=Dubin/> The highest flux of solar neutrinos come directly from the proton-proton interaction, and have a low energy, up to 400 keV. There are also several other significant production mechanisms, with energies up to 18 MeV.<ref name=Bellerive>A. Bellerive, [http://arxiv.org/abs/hep-ex/0312045 Review of solar neutrino experiments]. Int.J.Mod.Phys. A19 (2004) 1167-1179</ref> The parts of the Sun above the photosphere are referred to collectively as the ''solar atmosphere''.<ref name=Abhyankar1977>{{ cite journal |author=K.D. Abhyankar |title=A Survey of the Solar Atmospheric Models 1977 |journal=Bull. Astr. Soc. India |volume=5 |bibcode=1977BASI....5...40A |pages=40–44 |url=http://prints.iiap.res.in/handle/2248/510 }}</ref> "Neutrinos can be produced by energetic protons accelerated in solar magnetic fields. Such protons produce pions, and therefore muons, hence also neutrinos as a decay product, in the solar atmosphere."<ref name=Bahcall1987>{{ cite journal |author=J. N. Bahcall |author2=G. B. Field |author3=W. H. Press |title=Is solar neutrino capture rate correlated with sunspot number? |journal=The Astrophysical Journal |date=September 1, 1987 |volume=320 |issue=9 |pages=L69-73 |url=http://articles.adsabs.harvard.edu//full/1987ApJ...320L..69B/L000069.000.html |arxiv= |bibcode=1987ApJ...320L..69B |doi=10.1086/184978 |pmid= |accessdate=2013-07-07 }}</ref> "Energetic protons in the solar corona could explain Figure 2 [at right] only if (1) they tap a substantial fraction of the entire energy generated in the corona, (2) the energy generated in the corona is at least 3 times what has been deduced from the observations, (3) the vast majority of energetic protons do not escape the Sun, (4) the proton energy spectrum is unusually hard (''p''₀ = 300 MeV c^-1, and (5) the sign of the variation is opposite to what one would predict. As the likelihood of all of these conditions being fulfilled seems extremely small, we do not believe that neutrinos produced by energetic protons in the solar atmosphere contribute significantly to the neutrino capture in the ³⁷Cl experiment."<ref name=Bahcall1987/> "The total number of neutrinos of all types agrees with the number predicted by the computer model of the Sun. Electron neutrinos constitute about a third of the total number of neutrinos. [...] The missing neutrinos were actually present, but in the form of the more difficult to detect muon and tau neutrinos."<ref name=Bahcall2004>{{ cite book |author=John N. Bahcall |title=Solving the Mystery of the Missing Neutrinos |publisher=Nobel Media AB |location= |date=April 28, 2004 |url=http://www.nobelprize.org/nobel_prizes/themes/physics/bahcall/ |accessdate=2014-03-08 }}</ref> The reactions that produce the higher energy neutrinos: ν_µ and ν_τ are. For antiproton-proton annihilation at rest, a meson result is, for example, :<math>p^+ + \bar{p}^- \rightarrow \pi^+ + \pi^-,</math><ref name=Klempt>{{ cite journal |author=Eberhard Klempt |author2=Chris Batty |author3=Jean-Marc Richard |title=The antinucleon-nucleon interaction at low energy: annihilation dynamics |journal=Physics Reports |date=July 2005 |volume=413 |issue=4-5 |pages=197-317 |url=http://adsabs.harvard.edu/abs/2005PhR...413..197K |arxiv=hep-ex/0501020 |bibcode=2005PhR...413..197K |doi=10.1016/j.physrep.2005.03.002 |pmid= |accessdate=2014-03-09 }}</ref> :<math>{\pi}^+ \rightarrow {\mu}^+ + {\nu}_{\mu} \rightarrow e^+ + {\nu}_e + {\bar{\nu}}_{\mu} + {\nu}_{\mu},</math><ref name=Waxman>{{ cite journal |author=Eli Waxman |author2=John Bahcall |title=High energy neutrinos from astrophysical sources: An upper bound |journal=Physical Review D |date=December 14, 1998 |volume=59 |issue=2 |pages=e023002 |url=http://prd.aps.org/abstract/PRD/v59/i2/e023002 |arxiv=hep--ph/9807282 |bibcode= |doi=10.1103/PhysRevD.59.023002 |pmid= |accessdate=2014-03-09 }}</ref> and :<math>D_S \rightarrow \tau + \bar{\nu}_{\tau} \rightarrow \nu_{\tau} + \bar{\nu}_{\tau}.</math><ref name=Kodama>{{ cite journal |author=K. Kodama |author2=N. Ushida1 |author3=C. Andreopoulos |author4=N. Saoulidou |author5=G. Tzanakos |author6=P. Yager |author7=B. Baller |author8=D. Boehnlein |author9=W. Freeman |author10=B. Lundberg |author11=J. Morfin |author12=R. Rameika |author13=J.C. Yun |author14=J.S. Song |author15=C.S. Yoon |author16=S.H.Chung |author17=P. Berghaus |author18=M. Kubanstev |author19=N.W. Reay |author20=R. Sidwell |author21=N. Stanton |author22=S. Yoshida |author23=S. Aoki |author24=T. Hara |author25=J.T. Rhee |author26=D. Ciampa |author27=C. Erickson |author28=M. Graham |author29=K. Heller |author30=R. Rusack |author31=R. Schwienhorst |author32=J. Sielaff |author33=J. Trammell |author34=J. Wilcox |author35=K. Hoshino |author36=H. Jiko |author37=M. Miyanishi |author38=M. Komatsu |author39=M. Nakamura |author40=T. Nakano |author41=K. Niwa |author42=N. Nonaka |author43=K. Okada |author44=O. Sato |author45=T. Akdogan |author46=V. Paolone |author47=C. Rosenfeld |author48=A. Kulik |author49=T. Kafka |author50=W. Oliver |author51=T. Patzak |author52=J. Schneps |title=Observation of tau neutrino interactions |journal=Physics Letters B |date=April 12, 2001 |volume=504 |issue=3 |pages=218-24 |url=http://www.sciencedirect.com/science/article/pii/S0370269301003070 |arxiv= |bibcode= |doi= |pmid= |accessdate=2014-03-10 }}</ref> "All other sources of ν_τ are estimated to have contributed an additional 15%."<ref name=Kodama/> :<math>\tau \rightarrow e + \nu_{\tau} + \nu_e,</math><ref name=Kodama/> for two neutrinos.<ref name=Kodama/> :<math>\tau \rightarrow h + \nu_{\tau} + X,</math><ref name=Kodama/> where <math>h</math> is a hadron, for two neutrinos.<ref name=Kodama/> {{clear}} ==Gamma rays== {{main|Radiation astronomy/Gamma rays|Gamma-ray astronomy}} [[Image:Gamma sun1.jpg|thumb|right|250px|The Sun is seen in gamma rays by COMPTEL during a June 15, 1991, solar flare. Credit: COMPTEL team, University of New Hampshire.{{tlx|fairuse}}]] The surface of the Sun has yet to be detected as a gamma ray source, reflector, or in fluorescence. RHESSI was the first satellite to image solar gamma rays from a solar flare.<ref>[http://adsabs.harvard.edu/abs/2003ApJ...595L..77H] First Gamma-Ray Images of a Solar Flare (Hurford et al. 2003)</ref> {{clear}} ==X-rays== {{main|Radiation astronomy/X-rays|X-ray astronomy}} [[Image:X-ray image of the Pleiades.gif|thumb|right|250px|The image shows the Pleiades in X-rays, taken by ROSAT, where the brightest optical stars are inside the green squares. Credit: [[w:User:Worldtraveller|Worldtraveller]].{{tlx|free media}}]] "The Pleiades star cluster is one of the jewels of the northern sky. To the unaided eye it appears as an alluring group of stars in the constellation Taurus, while telescopic views reveal cluster stars surrounded by delicate blue wisps of dust-reflected starlight. To the X-ray telescopes on board the orbiting ROSAT observatory, the cluster also presents an impressive, but slightly altered, appearance. This false color image [at right] was produced from ROSAT observations by translating different X-ray energy bands to visual colors - the lowest energies are shown in red, medium in green, and highest energies in blue. (The green boxes mark the position of the seven brightest visual stars.) The Pleiades stars seen in X-rays have extremely hot, tenuous outer atmospheres called coronas and the range of colors corresponds to different coronal temperatures."<ref name=Nemiroff1999>{{ cite book |author=Robert Nemiroff |author2=Jerry Bonnell |title=X-Ray Pleiades |publisher=NASA/GSFC |location=Greenbelt, Maryland USA |date=August 28, 1999 |url=http://apod.nasa.gov/apod/ap990828.html |accessdate=2013-07-07 }}</ref> {{clear}} ==Ultraviolets== {{main|Radiation astronomy/Ultraviolets|Ultraviolet astronomy}} [[Image:August 2010 CME SDO.jpg|thumb|right|200px|A coronal mass ejection is shown in the ultraviolet. Credit: NASA/SDO.{{tlx|free media}}]] [[Image:STEREO B EUVI 171.jpg|thumb|left|250px|The chromosphere of the Sun shows in ultraviolets. Credit: STEREO (NASA).{{tlx|fairuse}}]] "One of the fastest CMEs in years was captured by the STEREO COR1 telescopes on August 1, 2010. ... This CME is seen to be heading towards Earth at speeds well over 1000 kilometers per second."<ref name=Zell/> "On August 1st, almost the entire Earth-facing side of the sun erupted in a tumult of activity. There was a C3-class solar flare, a solar tsunami, multiple filaments of magnetism lifting off the stellar surface, large-scale shaking of the solar corona, radio bursts, a coronal mass ejection and more. This extreme ultraviolet snapshot [at right] from the Solar Dynamics Observatory (SDO) shows the sun's northern hemisphere in mid-eruption. Different colors in the image represent different gas temperatures ranging from ~1 to 2 million degrees K."<ref name=Zell>{{ cite book |author=Holly Zell |title=Spacecraft Observes Coronal Mass Ejection |publisher=NASA |location=Washington, DC USA |date=August 4, 2010 |url=http://www.nasa.gov/topics/solarsystem/sunearthsystem/main/News080210-cme.html |accessdate=2013-07-07 }}</ref> {{clear}} ==Non-polar solar coronal holes== [[Image:Coronalhole.jpg|right|thumb|250px|Solar Disk with Coronal Hole - May 25, 2007 - by NASA STEREO (Solar TErrestrial RElations Observatory). Credit: NASA STEREO (Solar TErrestrial RElations Observatory).{{tlx|free media}}]] [[Image:417176main SDO Guide CMR Page 26 Image 0002.jpg|left|thumb|250px|A coronal hole is shown in extreme UV light. Credit: NASA.{{tlx|free media}}]] [[Image:Cor hole May-thumb-570x570-123594.jpg|thumb|right|250px|Coronal holes are areas on the Sun's corona that are darker, lower-density, and (relatively) colder than the rest of the plasma above the surface of our nearest star. Credit: NASA.{{tlx|fairuse}}]] [[Image:Two Coronal Holes on the Sun Viewed by SDO (16658479920).jpg|left|thumb|250px|NASA’s Solar Dynamics Observatory, or SDO, captured this solar image on March 16, 2015, which clearly shows two dark patches, known as coronal holes. Credit: NASA/Goddard/SDO.{{tlx|free media}}]] [[Image:Coronal Hole Front and Center.jpg|right|thumb|300px|The high-speed solar wind originating from this coronal hole, imaged hereon Oct. 10, 2015, by NASA's Solar Dynamics Observatory, created a geomagnetic storm near Earth that resulted in several nights of auroras. Credit: NASA/SDO.{{tlx|free media}}]] [[Image:PIA22197-SunFormsQuestionMark-20171222.jpg|left|thumb|250px|NASA's Solar Dynamics Observatory observed an elongated coronal hole (the darker area near the center) seeming to shape itself into a single, recognizable question mark over the period of one day (Dec. 21-22, 2017). Credit: NASA/GSFC/Solar Dynamics Observatory.{{tlx|free media}}]] "The striking absence of green emission above both polar regions at activity minimum led Waldmeier (1957) to use the German term 'Koronalöcher', ie, coronal holes."<ref name=Schwenn>{{ cite journal |author=R. Schwenn |author2=B. Inhester |author3=S. P. Plunkett |author4=A. Epple |author5=B. Podlipnik |author6=D. K. Bedford |author7=C. J. Eyles |author8=G. M. Simnett |author9=S. J. Tappin |author10=M. V. Bout |author11=et al. |title=First View of the Extended Green-Line Emission Corona At Solar Activity Minimum Using the Lasco-C1 Coronagraph on Soho |journal=Solar Physics |month=October |year=1997 |volume=175 |issue=2 |pages=667-84 |url=http://www.springerlink.com/index/R10HN0R60R081237.pdf |arxiv= |bibcode= |doi=10.1023/A:1004948913883 |pmid= |accessdate=2012-02-17 }}</ref> "Here we restrict ourselves to a qualitative study of large scale structures of the green emission line corona."<ref name=Schwenn/> The image descriptions that follow emphasize various non-polar holes. For the coronal hole from 25 May 2007: the image of the solar coronal cloud at top right shows both of the polar coronal holes and one apparently isolated, non-polar coronal hole. Second image down on the right: "Coronal holes are areas on the sun's corona that are darker, lower-density, and (relatively) colder than the rest of the plasma on the surface of our nearest star. They're the source of the kind of solar wind gusts that carry solar particles out to our magnetosphere and beyond, causing auroras (and, less awesomely, geomagnetic storms) here on Earth."<ref name=Garber>{{ cite book |author=Megan Garber |title=No Big Deal, Just a Giant Hole in the Sun |publisher=The Atlantic |location= |date=5 June 2013 |url=http://www.theatlantic.com/technology/archive/2013/06/no-big-deal-just-a-giant-hole-in-the-sun/276564/ |accessdate=2015-05-18 }}</ref> "When coronal holes are captured in extreme ultraviolet light images, they reveal themselves as dark spots that appear, to human eyes, to be plasma voids."<ref name=Garber/> "Well, last week -- between May 28 and 31 -- one of those coronal holes rotated toward Earth. It was a big one: "one of the largest," NASA says, "we have seen in a year or more." And the Solar Dynamics Observatory's Atmospheric Imaging Assembly, fortunately, got a shot of the thing. Above, via a combination of three wavelengths of UV light, is an image of the hole. It's pretty gorgeous, as holes go."<ref name=Garber/> "And while coronal holes are more likely to affect Earth after they've rotated more than halfway around the visible hemisphere of the sun -- which was the case with this guy -- the most this one would have done, astronomers say, was to generate some aurora."<ref name=Garber/> The image second down on the right shows one of the largest non-polar coronal holes ever observed in May, apparently in 2013. For the second image down on the left: "NASA’s Solar Dynamics Observatory, or SDO, captured this solar image on March 16, 2015, which clearly shows two dark patches, known as coronal holes. The larger coronal hole of the two, near the southern pole, covers an estimated 6- to 8-percent of the total solar surface. While that may not sound significant, it is one of the largest polar holes scientists have observed in decades. The smaller coronal hole, towards the opposite pole, is long and narrow. It covers about 3.8 billion square miles on the sun - only about 0.16-percent of the solar surface."<ref name=Goddard2015>{{ cite book |author=NASA/Goddard/SDO |title=Two Coronal Holes on the Sun Viewed by SDO |publisher=Goddard Space Flight Center |location=Greenbelt, Maryland USA |date=17 March 2015 |editor= |pages=1 |url=https://www.flickr.com/people/24662369@N07 |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2018-02-07 }}</ref> Per the third image down on the right: "The dark area across the top of the sun in this image is a coronal hole, a region on the sun where the magnetic field is open to inter planetary space, sending coronal material speeding out in what is called a high-speed solar wind stream. The high-speed solar wind originating from this coronal hole, imaged hereon Oct. 10, 2015, by NASA's Solar Dynamics Observatory, created a geomagnetic storm near Earth that resulted in several nights of auroras. This image was taken in wavelengths of 193 Angstroms, which is invisible to our eyes and is typically colorized in bronze."<ref name=NASA>{{ cite book |author=NASA/SDO |title=Coronal Hole Front and Center |publisher=GSFC |location=Greenbelt, Maryland USA |date=15 October 2015 |editor= |pages=1 |url=https://www.nasa.gov/image-feature/goddard/coronal-hole-front-and-center |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2018-02-07 }}</ref> Relative to the third image down on the left: "Oddly enough, an elongated coronal hole (the darker area near the center) seems to shape itself into a single, recognizable question mark over the period of one day (Dec. 21-22, 2017). Coronal holes are areas of open magnetic field that appear darker in extreme ultraviolet light, as is seen here. These holes are the source of streaming plasma that we call solar wind."<ref name=Dynamics>{{ cite web |author=NASA/GSFC/Solar Dynamics Observatory |title=PIA22197: The Sun Forms a Question |publisher=GSFC |location=Greenbelt, Maryland USA |date=29 December 2017 |editor= |pages=1 |url=https://photojournal.jpl.nasa.gov/jpeg/PIA22197.jpg |arxiv= |bibcode= |doi= |pmid= |isbn= |accessdate=2018-02-07 }}</ref> While the hole is connected to the polar coronal hole it does extend to mid-latitudes. {{clear}} ==Saturn== "Saturn's corona plays a major role in supplying hydrogen to the circumplanetary volume."<ref name=Smyth>{{ cite web |author=W.H. Smyth, M.R. Combi |title=Extended atmospheres of outer planet satellites and comets. Interim report, 15 June-14 September 1987 |publisher= |location= |date=November 1, 1987 |pages=122 |url=http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=5275119 |accessdate=2013-07-10 }}</ref> "This cloud probably connects to the extended hydrogen corona of Saturn (Broadfoot et al., 1981; Shemansky and Hall, 1992) and to hydrogen-rich icy surfaces in the inner magnetosphere."<ref name=Young>{{ cite journal |author=D. T. Young |author2=J. J. Berthelier |author3=M. Blanc |author4=J. L. Burch |author5=A. J. Coates |author6=R. Goldstein |author7=M. Grande |author8=T. W. Hill |author9=R. E. Johnson |author10=V. Kelha |author11=D. J. Mccomas |author12=E. C. Sittler |author13=K. R. Svenes |author14=K. Szegö |author15=P. Tanskanen |author16=K. Ahola |author17=D. Anderson |author18=S. Bakshi |author19=R. A. Baragiola |author20=B. L. Barraclough |author21=R. K. Black |author22=S. Bolton |author23=T. Booker |author24=R. Bowman |author25=P. Casey |author26=F. J. Crary |author27=D. Delapp |author28=G. Dirks |author29=N. Eaker |author30=H. Funsten |author31=J. D. Furman |author32=J. T. Gosling |author33=H. Hannula |author34=C. Holmlund |author35=H. Huomo |author36=J. M. Illiano |author37=P. Jensen |author38=M. A. Johnson |author39=D. R. Linder |author40=T. Luntama |author41=S. Maurice |author42=K. P. Mccabe |author43=K. Mursula |author44=B. T. Narheim |author45=J. E. Nordholt |author46=A. Preece |author47=J. Rudzki |author48=A. Ruitberg |author49=K. Smith |author50=S. Szalai |author51=M. F. Thomsen |author52=K. Viherkanto |author53=J. Vilppola |author54=T. Vollmer |author55=T. E. Wahl |author56=M. Wüest |author57=T. Ylikorpi |author58=C. Zinsmeyer |title=Cassini plasma spectrometer investigation |journal=Space Science Reviews |month=September |year=2004 |volume=114 |issue=1-4 |pages=1-112 |url=http://link.springer.com/article/10.1007/s11214-004-1406-4 |arxiv= |bibcode= |doi=10.1007/s11214-004-1406-4 |pmid= |accessdate=2013-07-10 }}</ref> ==Brown dwarfs== [[Image:Lp94420 duo m.jpg|thumb|250px|[[w:Chandra X-ray Observatory|Chandra]] image of LP 944-20 before flare and during flare. Credit: NASA.{{tlx|free media}}]] Some brown dwarfs emit X-rays. Here are some X-ray milestones from the same article: * 1998: First X-ray-emitting brown dwarf found. Cha Halpha 1, an M8 object in the [[w:Chamaeleon I|Chamaeleon I]] dark cloud, is determined to be an X-ray source, similar to convective late-type stars. * December 15, 1999: First X-ray flare detected from a brown dwarf. A team at the University of California monitoring LP 944-20 (60 Jupiter masses, 16 ly away) via the [[w:Chandra X-ray Observatory|Chandra X-ray Observatory]], catches a 2-hour flare. X-ray flares detected from brown dwarfs since late 1999 suggest changing [[w:magnetic field of celestial bodies|magnetic fields]] similar to those in very low-mass stars. When combined with the rapid rotation that most brown dwarfs exhibit, conditions [may exist] for the development of a strong, tangled [[w:magnetic field|magnetic field]] near the surface. The flare observed by [[w:Chandra X-ray Observatory|Chandra]] from LP 944-20 could have its origin in the turbulent magnetized hot material that may conduct heat to the atmosphere, allowing electric currents to flow and produce an X-ray flare, like a stroke of [[w:lightning|lightning]]. The absence of X-rays from LP 944-20 during the non flaring period is also a significant result. It sets the lowest observational limit on steady X-ray power produced by a brown dwarf star, and shows that coronas cease to exist as the surface temperature of a brown dwarf cools below about 2500°C and becomes electrically neutral. Using NASA's [[w:Chandra X-ray Observatory|Chandra X-ray Observatory]], scientists have detected X-rays from a low-mass brown dwarf in a multiple star system.<ref name=Williams2003>{{ cite book |date=14 April 2003 |title=X-rays from a Brown Dwarf's Corona |url=http://www.williams.edu/Astronomy/jay/chapter18_etu6.html }}</ref> This is the first time that a brown dwarf this close to its parent star(s) (Sun-like stars TWA 5A) has been resolved in X-rays.<ref name=Williams2003/> "Our Chandra data show that the X-rays originate from the brown dwarf's coronal plasma which is some 3 million degrees Celsius", said Yohko Tsuboi of [[w:Chuo University|Chuo University]] in Tokyo.<ref name=Williams2003/> "This brown dwarf is as bright as the Sun today in X-ray light, while it is fifty times less massive than the Sun", said Tsuboi.<ref name=Williams2003/> "This observation, thus, raises the possibility that even massive planets might emit X-rays by themselves during their youth!"<ref name=Williams2003/> {{clear}} ==Heliophysics== {{main|Stars/Sun/Heliophysics|Heliophysics}} "Heliophysics is concerned with laws that give rise to structures and processes that occur in magnetized plasmas and in neutral environments in the local cosmos, both temporal (weather-like) and persistent (climate-like). These laws systematize the results of half a century of exploring space that followed centuries of ground-based observations. During this time spacecraft have imaged the Sun over many wavelengths and resolutions. They have visited every planet, all major satellites and many minor ones, and a selection of comets and asteroids. Beyond this they have traversed the expanse of the [[heliosphere]] itself. Out of the vast store of data so accumulated, the laws and principles of heliophysics are emerging to describe structures that are natural to magnetized plasmas and neutrals in cosmic settings and to specify principles that make the heliosphere a realm of numerous, original dynamical modes."<ref name=Siscoe>{{ cite book |author=George L. Siscoe |author2=Carolus J. Schrijver |title=Perspective on heliophysics, In: ''Heliophysics: Space Storms and Radiation: Causes and Effects'' |publisher=Cambridge University Press |location=Cambridge, UK |date=May 2010 |editor=Carolus J. Schrijver |editor2=George L. Siscoe |pages=1-10 |url=http://www.langtoninfo.com/web_content/9780521760515_excerpt.pdf |arxiv= |bibcode= |doi= |pmid= |isbn=978-0-521-76051-5 |accessdate=2014-08-02 }}</ref> "In the case of heliophysics, probably most of its laws have yet to be discovered, since the project of finding them is young. Moreover, heliophysics is a unique hybrid between meteorology and astrophysics with substantial components of physics and chemistry. Thus, many of the laws of heliophysics that we can list at this time might be subjects for research in meteorology (e.g. the field of aeronomy), astrophysics (e.g. shock waves and cosmic rays), physics (e.g. magnetic reconnection and particle energization), or chemistry (e.g. reaction rates in planetary ionospheres and thermospheres)."<ref name=Siscoe/> ==Magnetohydrodynamics== "When magnetic fields "reconnect" in a turbulent magnetohydrodynamic (MHD) plasma, electric fields are generated in which particles can be accelerated (Matthaeus ''et al.'', 1984; Sorrell, 1984)."<ref name="Gaisser">{{cite book |author=Thomas K. Gaisser |title=Cosmic Rays and Particle Physics |publisher=Cambridge University Press |location= |year=1990 |editor= |pages=279 |url=http://books.google.com/books?hl=en&lr=&id=qJ7Z6oIMqeUC&oi=fnd&pg=PR15&ots=IxjwLxBwXu&sig=voHKIYstBlBYla4jcbur_b-Zwxs |arxiv= |bibcode= |doi= |pmid= |isbn=0521339316 |accessdate=2014-01-11 }}</ref> ==Stellar sciences== {{main|Stars/Sciences}} [[Image:November 3 2009 GOES14 Image.png|thumb|left|250px|The GOES 14 spacecraft took this image of the '''Sun'''. Credit: NOAA/Space Weather Prediction Center and the NWS Internet Services Team.{{tlx|free media}}]] The GOES 14 spacecraft carries a Solar X-ray Imager that took this image [at right] of the '''Sun''' during the most recent quiet period. The Sun appears dark because of the wavelength band of observation and the lack of X-rays. Except for X-ray emission that suggests a circular disc with some isolated X-ray sources at specific locations, the Sun is almost invisible. X-rays are primarily emitted from plasmas near 10⁶ K. {{clear}} ==Focusing Optics X-ray Solar Imagers== [[Image:FOXSI-2 sounding rocket.jpg|thumb|left|250px|The photograph shows the FOXSI team in front of the FOXSI-2 sounding rocket on the launch pad. Credit: NASA, Säm Krucker, UC Berkeley.{{tlx|fairuse}}]] [[Image:FOXSI-2 Sounding Rocket Payload.png|thumb|right|250px|A high resolution render shows the FOXSI-2 payload. Credit: [[w:user:Schriste|Schriste]].{{tlx|fairuse}}]] The Focusing Optics X-ray Solar Imager, or FOXSI, is a sounding rocket payload built to observe the Sun, composed of seven identical Wolter-I telescope modules, as well as Silicon and Cadmium Telluride strip detectors originally developed for the HXT telescope on the Japanese Hitomi mission. The FOXSI payload flew two times,<ref> {{cite web | url = https://www.nasa.gov/content/goddard/nasa-funded-foxsi-to-observe-x-rays-from-sun | title = NASA-funded FOXSI to Observe X-Rays From Sun | last = Fox | first = Karen | date =November 1, 2015 | publisher = NASA | accessdate= July 28, 2015 }}</ref><ref>{{cite web | url = http://www.nasa.gov/mission_pages/sounding-rockets/news/xray-scope.html#.VbbtWnh41FI | title = A Next-Generation X-Ray Telescope Launches | last = Fox | first = Karen | date = July 27, 2015 | publisher = NASA | accessdate= July 27, 2015 }}</ref> and previously in 2012. Like most sounding rockets, FOXSI flew for approximately 15 minutes per mission and observed the Sun for about 5 minutes while in space. During its first flight, FOXSI successfully imaged a solar microflare in the hard x-ray band for the first time.<ref name=Krucker>{{cite journal |title=First Images from the Focusing Optics X-Ray Solar Imager |journal= The Astrophysical Journal Letters |volume=793 |issue= 2 |page=L32 |date=2014 |bibcode=2014ApJ...793L..32K |doi = 10.1088/2041-8205/793/2/L32 |last=Krucker | first=S. |last2=Christe | first2=S. |last3=Glesener|first3=L. |last4= Ishikawa|first4=S. |last5=Ramsey|first5=B. |last6=Takahashi|first6=T. |last7=Watanabe|first7=S. |last8=Saito|first8=S. |last9=Gubarev|first9=M. }}</ref> FOXSI's third mission had a successful launch on September 7, 2018 from White Sands, New Mexico, which included a combination of Silicon and improved Cadmium Telluride detectors,<ref name=Ishikawa>{{Cite journal |last=Ishikawa|first=S. |last2=Katsuragawa|first2=M. |last3=Watanabe|first3=S. |last4=Uchida|first4=Y. |last5=Takeda|first5=S. |last6=Takahashi|first6=T. |last7=Saito|first7=S. |last8=Glesener|first8=L. |last9=Buitrago-Casas|first9=J. C. |date=2016 |title=Fine-pitch CdTe detector for hard X-ray imaging and spectroscopy of the Sun with the FOXSI rocket experiment |journal=Journal of Geophysical Research: Space Physics |language=en |volume=121 |issue=7 |pages=6009–6016 |doi=10.1002/2016ja022631|issn=2169-9402|arxiv=1606.03887|bibcode=2016JGRA..121.6009I}}</ref> as well as one CMOS soft x-ray detector. Two of the telescope modules were updated from 7-shell to 10-shell configurations, and the payload also introduced collimator technology to reduce the impact of singly-reflected rays.<ref name=Buitrago>{{Cite book |last=Buitrago-Casas|first=J. C. |last2=Glesener|first2=L. |last3=Christe|first3=S. |last4=Ramsey|first4=B. |last5=Elsner|first5=R. |last6=Courtade|first6=S. |last7=Vievering|first7=J. |last8=Subramania|first8=A. |last9=Krucker|first9=S. |last10=Bale|first10=S. |date=2017 |title=Methods for reducing singly reflected rays on the Wolter-I focusing mirrors of the FOXSI rocket experiment, In: ''Optics for EUV, X-Ray, and Gamma-Ray Astronomy VIII'' |series=Proceedings of SPIE |volume=10399 |page=103990J |bibcode=2017SPD....4830504B |doi=10.1117/12.2274675 |{{isbn|9781510612556}} }}</ref> {{clear}} ==See also== {{div col|colwidth=20em}} * [[Plasmas/Plasma objects/Coronal clouds|Coronal clouds]] * [[Radiation/Cosmic rays|Cosmic-ray astronomy]] * [[Radiation astronomy/Electrons|Electron astronomy]] * [[Radiation astronomy/Fieries|Fiery meteor astronomy]] * [[Stars/Flares|Flare stars]] * [[Stars/Sun/Heliophysics|Heliophysics]] * [[Radiation astronomy/Lightnings|Lightning astronomy]] * [[Radiation astronomy/Nebulas|Nebula astronomy]] * [[Stars/Nova-likes|Nova-like stars]] * [[Stars/Novas|Novas]] * [[Stars/Os|O-type stars]] * [[Radiation astronomy/Protons|Proton astronomy]] * [[Stars/Quasars|Quasars]] * [[Stars/Star fissions|Star fissions]] * [[Stars/Active regions|Stellar active regions]] * [[Stars/Surface fusion|Surface fusions]] * [[Stars/Supernovas|Supernovas]] * [[Stars/Variables|Variable stars]] * [[Stars/Wolf-Rayets|Wolf-Rayet stars]] * [[Stars/X-rays|X-ray stars]] {{Div col end}} ==References== {{reflist|2}} ==External links== * [http://www.adsabs.harvard.edu/ The SAO/NASA Astrophysics Data System] * [http://simbad.u-strasbg.fr/simbad/ SIMBAD Astronomical Database] <!-- footer templates --> {{Radiation astronomy resources}}{{Sisterlinks|Plasma radiation astronomy}} <!-- footer categories --> [[Category:Radiation astronomy/Lectures]] h96g1u31q44bz11l3ojokd90nba0jl7 0 266624 2413992 2394105 2022-08-12T17:15:42Z Ncharamut 2824970 /* Preparing a Manuscript */ edited SOP and added some information wikitext text/x-wiki <noinclude>{{Helping Give Away Psychological Science Banner}}</noinclude> = Submitting to the Wiki Journal of Medicine Tips = == Preparing a Manuscript == Note: How to write a scientific paper is beyond the scope of these instructions, but here I provide tips for picking subject areas and logistics for getting ready to submit. Please see this [https://docs.google.com/document/d/1G5QgJ1EYvSPRPldZZ3IBpMLRlv7cjbEteicozxItrGM/edit document] for steps to writing an academic paper. # Decide what to write about: ## Use the link below to check if your topic fits one of the WikiJournals. As of now, HGAPS has mainly sent review articles rather than original research, but this could change. ### [[WikiJournal of Medicine/Publishing|WikiJournal of Medicine]] ### [[WikiJournal of Science/Submission|WikiJournal of Science]] ### [[WikiJournal of Humanities/Submission|WikiJournal of Humanities]] # Preparing the draft ## We recommend using a Google document or some other sort of collaborative document if you intend to have more than one person editing at the same time ### Caution- formatting from a document to a Wiki page will be a fair amount of work, so if you can start it on Wiki, you may want to do that (you can also do this in someone's sandbox) ## If not, or at the next step, you can either create a page in the HGAPS suite on Wikiversity or go ahead and create a preprint (which will have to be done eventually either way) ## To create a preprint, navigate to this [[WikiJournal of Medicine/Submission letter for multiple authors|link]] and type in what you would like your article name to be where the box is ## Now you have a preprint! This document can be revised up to and even after you submit the authorship declaration forum (the submission document) ### Note- the default format only allows for 10 authors, but an editor can add space for more if needed ##Make sure that the faculty advisor for this paper reads over the draft before submitting == Submitting Your Article == # Now that your article is prepared, you’re ready to submit. Congrats! # Make your article into a preprint ## If your article is not already a WikiJournal preprint, you will need to make it one ## Use [[WikiJournal Preprints|this link]] to title and create the preprint page # The main step to submitting the article is completing the authorship declaration form on the right side at the top of the preprint ## You can see the form [https://docs.google.com/forms/d/e/1FAIpQLSf-Nu7hjiTeJ5uQ5ozMOIivWZjeyJCPLwAUOuNDP1MVKUbCSQ/viewform here] ## Consider (with advice) if there are any individuals you would like to commend or exclude as reviewers. You will be able to put those people's names on the submission form ## Also consider whether you want to request that your article be integrated into Wikipedia. If there is no page on your topic (or it is low quality) and your paper reads like a Wikipedia article, you can let them know that you would like it considered to replace all or part of an article   ## Once you fill out all sections of the submission form, you can submit # Congrats! Your article is submitted! == Moving Through the Publication Process == * Publication steps are as follows: ** Manuscript is received and authorship declaration form has been submitted ** Editorial board determines article suitability and determines if they will review your paper ** A peer review coordinator is determined *** This is who you can contact with questions and who will find your peer reviewers ** Peer reviewers write their reviews and they are posted on the talk page of your submission ** Once you receive peer review comments, you will respond to the comments *** you can use [[WikiJournal User Group/Editorial guidelines#Article%20amendments%20and%20publication%20decision|this template]] for responding to peer review ** After you submit your revision, peer reviewers will review the changes ** The editorial board makes a publication decision ** If accepted, the article will get a stable PDF and DOI *** Any information meant for Wikipedia will be transferred there = Disseminating Your Article = * Preprints ** PsyArXiv is a useful tool that will allow your preprint to be indexed in search engines * Listservs ** You (or someone else on your behalf) can disseminate your article via listservs to the appropriate audience * Social media ** HGAPS social media is also a great way to get your article out there! ** Academic twitter is a great way to share your publication cu0nf6z8pypren0w8ucvzerkwgxaejm 2414011 2413992 2022-08-12T23:03:13Z JBondareva3x7 2927239 /* Preparing a Manuscript */ did some grammatical edits to the preparing a manuscript section wikitext text/x-wiki <noinclude>{{Helping Give Away Psychological Science Banner}}</noinclude> = Submitting to the Wiki Journal of Medicine Tips = == Preparing a Manuscript == Note: How to write a scientific paper is beyond the scope of these instructions, but here are tips for picking subject areas and logistics for getting ready to submit. Please see this [https://docs.google.com/document/d/1G5QgJ1EYvSPRPldZZ3IBpMLRlv7cjbEteicozxItrGM/edit document] for steps to write an academic paper. # Decide what to write about: ## Use the link below to check if your topic fits one of the WikiJournals. As of now, HGAPS has mainly sent review articles rather than original research, but this could change. ### [[WikiJournal of Medicine/Publishing|WikiJournal of Medicine]] ### [[WikiJournal of Science/Submission|WikiJournal of Science]] ### [[WikiJournal of Humanities/Submission|WikiJournal of Humanities]] # Preparing the draft: ## We recommend using a Google document or some other sort of collaborative document if you intend to have more than one person editing at the same time. ### Caution- formatting from a document to a Wiki page will be a fair amount of work, so if you can start it on Wiki, you may want to do that (you can also do this in someone's sandbox). ## If not, or at the next step, you can either create a page in the HGAPS suite on Wikiversity or go ahead and create a preprint (which will have to be done eventually either way). ## To create a preprint, navigate to this [[WikiJournal of Medicine/Submission letter for multiple authors|link]] and type into the box what you would like your article name to be. ## Now you have a preprint! This document can be revised up to and even after you submit the authorship declaration forum (the submission document). ### Note- the default format only allows for 10 authors, but an editor can add space for more if needed. ##Make sure that the faculty advisor for this paper reads over the draft before submitting. == Submitting Your Article == # Now that your article is prepared, you’re ready to submit. Congrats! # Make your article into a preprint ## If your article is not already a WikiJournal preprint, you will need to make it one ## Use [[WikiJournal Preprints|this link]] to title and create the preprint page # The main step to submitting the article is completing the authorship declaration form on the right side at the top of the preprint ## You can see the form [https://docs.google.com/forms/d/e/1FAIpQLSf-Nu7hjiTeJ5uQ5ozMOIivWZjeyJCPLwAUOuNDP1MVKUbCSQ/viewform here] ## Consider (with advice) if there are any individuals you would like to commend or exclude as reviewers. You will be able to put those people's names on the submission form ## Also consider whether you want to request that your article be integrated into Wikipedia. If there is no page on your topic (or it is low quality) and your paper reads like a Wikipedia article, you can let them know that you would like it considered to replace all or part of an article   ## Once you fill out all sections of the submission form, you can submit # Congrats! Your article is submitted! == Moving Through the Publication Process == * Publication steps are as follows: ** Manuscript is received and authorship declaration form has been submitted ** Editorial board determines article suitability and determines if they will review your paper ** A peer review coordinator is determined *** This is who you can contact with questions and who will find your peer reviewers ** Peer reviewers write their reviews and they are posted on the talk page of your submission ** Once you receive peer review comments, you will respond to the comments *** you can use [[WikiJournal User Group/Editorial guidelines#Article%20amendments%20and%20publication%20decision|this template]] for responding to peer review ** After you submit your revision, peer reviewers will review the changes ** The editorial board makes a publication decision ** If accepted, the article will get a stable PDF and DOI *** Any information meant for Wikipedia will be transferred there = Disseminating Your Article = * Preprints ** PsyArXiv is a useful tool that will allow your preprint to be indexed in search engines * Listservs ** You (or someone else on your behalf) can disseminate your article via listservs to the appropriate audience * Social media ** HGAPS social media is also a great way to get your article out there! ** Academic twitter is a great way to share your publication 1bh0oaosds63t5pqnaop67ytwkt2vvz 2414012 2414011 2022-08-12T23:04:08Z JBondareva3x7 2927239 /* Submitting Your Article */ added periods wikitext text/x-wiki <noinclude>{{Helping Give Away Psychological Science Banner}}</noinclude> = Submitting to the Wiki Journal of Medicine Tips = == Preparing a Manuscript == Note: How to write a scientific paper is beyond the scope of these instructions, but here are tips for picking subject areas and logistics for getting ready to submit. Please see this [https://docs.google.com/document/d/1G5QgJ1EYvSPRPldZZ3IBpMLRlv7cjbEteicozxItrGM/edit document] for steps to write an academic paper. # Decide what to write about: ## Use the link below to check if your topic fits one of the WikiJournals. As of now, HGAPS has mainly sent review articles rather than original research, but this could change. ### [[WikiJournal of Medicine/Publishing|WikiJournal of Medicine]] ### [[WikiJournal of Science/Submission|WikiJournal of Science]] ### [[WikiJournal of Humanities/Submission|WikiJournal of Humanities]] # Preparing the draft: ## We recommend using a Google document or some other sort of collaborative document if you intend to have more than one person editing at the same time. ### Caution- formatting from a document to a Wiki page will be a fair amount of work, so if you can start it on Wiki, you may want to do that (you can also do this in someone's sandbox). ## If not, or at the next step, you can either create a page in the HGAPS suite on Wikiversity or go ahead and create a preprint (which will have to be done eventually either way). ## To create a preprint, navigate to this [[WikiJournal of Medicine/Submission letter for multiple authors|link]] and type into the box what you would like your article name to be. ## Now you have a preprint! This document can be revised up to and even after you submit the authorship declaration forum (the submission document). ### Note- the default format only allows for 10 authors, but an editor can add space for more if needed. ##Make sure that the faculty advisor for this paper reads over the draft before submitting. == Submitting Your Article == # Now that your article is prepared, you’re ready to submit. Congrats! # Make your article into a preprint. ## If your article is not already a WikiJournal preprint, you will need to make it one. ## Use [[WikiJournal Preprints|this link]] to title and create the preprint page. # The main step to submitting the article is completing the authorship declaration form on the right side at the top of the preprint. ## You can see the form [https://docs.google.com/forms/d/e/1FAIpQLSf-Nu7hjiTeJ5uQ5ozMOIivWZjeyJCPLwAUOuNDP1MVKUbCSQ/viewform here] . ## Consider (with advice) if there are any individuals you would like to commend or exclude as reviewers. You will be able to put those people's names on the submission form. ## Also consider whether you want to request that your article be integrated into Wikipedia. If there is no page on your topic (or it is low quality) and your paper reads like a Wikipedia article, you can let them know that you would like it considered to replace all or part of an article. ## Once you fill out all sections of the submission form, you can submit. # Congrats! Your article is submitted! == Moving Through the Publication Process == * Publication steps are as follows: ** Manuscript is received and authorship declaration form has been submitted ** Editorial board determines article suitability and determines if they will review your paper ** A peer review coordinator is determined *** This is who you can contact with questions and who will find your peer reviewers ** Peer reviewers write their reviews and they are posted on the talk page of your submission ** Once you receive peer review comments, you will respond to the comments *** you can use [[WikiJournal User Group/Editorial guidelines#Article%20amendments%20and%20publication%20decision|this template]] for responding to peer review ** After you submit your revision, peer reviewers will review the changes ** The editorial board makes a publication decision ** If accepted, the article will get a stable PDF and DOI *** Any information meant for Wikipedia will be transferred there = Disseminating Your Article = * Preprints ** PsyArXiv is a useful tool that will allow your preprint to be indexed in search engines * Listservs ** You (or someone else on your behalf) can disseminate your article via listservs to the appropriate audience * Social media ** HGAPS social media is also a great way to get your article out there! ** Academic twitter is a great way to share your publication 88sytw5yikbtbjhmylpx1jnzdfi9atj 0 267591 2414074 2413104 2022-08-13T10:57:24Z D.H 52339 /* Lorentz transformation via hyperbolic functions */ wikitext text/x-wiki {{../Lorentz transformation (header)}} ==Lorentz transformation via hyperbolic functions== ===Translation in the hyperbolic plane=== The case of a Lorentz transformation without spatial rotation is called a [[w:Lorentz boost]]. The simplest case can be given, for instance, by setting ''n=1'' in the [[../Lorentz transformation (general)#math_1a|E:most general Lorentz transformation '''(1a)''']]: {{NumBlk|:|<math>\begin{matrix}-x_{0}^{2}+x_{1}^{2}=-x_{0}^{\prime2}+x_{1}^{\prime2}\\ \hline \begin{align}x_{0}^{\prime} & =x_{0}g_{00}+x_{1}g_{01}\\ x_{1}^{\prime} & =x_{0}g_{10}+x_{1}g_{11}\\ \\ x_{0} & =x_{0}^{\prime}g_{00}-x_{1}^{\prime}g_{10}\\ x_{1} & =-x_{0}^{\prime}g_{01}+x_{1}^{\prime}g_{11} \end{align} \left|\begin{align}g_{01}^{2}-g_{00}^{2} & =-1\\ g_{11}^{2}-g_{10}^{2} & =1\\ g_{01}g_{11}-g_{00}g_{10} & =0\\ g_{10}^{2}-g_{00}^{2} & =-1\\ g_{11}^{2}-g_{01}^{2} & =1\\ g_{10}g_{11}-g_{00}g_{01} & =0 \end{align} \rightarrow\begin{align}g_{00}^{2} & =g_{11}^{2}\\ g_{01}^{2} & =g_{10}^{2} \end{align} \right. \end{matrix}</math> or in matrix notation <math>\left.\begin{align}\mathbf{x}' & =\begin{bmatrix}g_{00} & g_{01}\\ g_{10} & g_{11} \end{bmatrix}\cdot\mathbf{x}\\ \mathbf{x} & =\begin{bmatrix}g_{00} & -g_{10}\\ -g_{01} & g_{11} \end{bmatrix}\cdot\mathbf{x}' \end{align} \quad\right|\quad\det\begin{bmatrix}g_{00} & g_{01}\\ g_{10} & g_{11} \end{bmatrix}=1</math>|{{equationRef|3a}}}} which resembles precisely the relations of [[w:hyperbolic function]]s in terms of [[w:hyperbolic angle]] <math>\eta</math>. Thus a Lorentz boost or [[w:hyperbolic rotation]] (being the same as a rotation around an imaginary angle <math>i\eta=\phi</math> in [[../Lorentz transformation (imaginary)#math_2b|E:'''(2b)''']] or a [[w:Translation (geometry)|translation]] in the hyperbolic plane in terms of the hyperboloid model) is given by {{NumBlk|:|<math>\begin{matrix}-x_{0}^{2}+x_{1}^{2}=-x_{0}^{\prime2}+x_{1}^{\prime2}\\ \hline g_{00}=g_{11}=\cosh\eta,\ g_{01}=g_{10}=-\sinh\eta\\ \hline \left.\begin{align} & \quad\quad(A) & & \quad\quad(B) & & \quad\quad(C)\\ x_{0}^{\prime} & =x_{0}\cosh\eta-x_{1}\sinh\eta & & =\frac{x_{0}-x_{1}\tanh\eta}{\sqrt{1-\tanh^{2}\eta}} & & =\frac{x_{0}-x_{1}v}{\sqrt{1-v^{2}}}\\ x_{1}^{\prime} & =-x_{0}\sinh\eta+x_{1}\cosh\eta & & =\frac{x_{1}-x_{0}\tanh\eta}{\sqrt{1-\tanh^{2}\eta}} & & =\frac{x_{1}-x_{0}v}{\sqrt{1-v^{2}}}\\ \\ x_{0} & =x_{0}^{\prime}\cosh\eta+x_{1}^{\prime}\sinh\eta & & =\frac{x_{0}^{\prime}+x_{1}^{\prime}\tanh\eta}{\sqrt{1-\tanh^{2}\eta}} & & =\frac{x_{0}^{\prime}+x_{1}^{\prime}v}{\sqrt{1-v^{2}}}\\ x_{1} & =x_{0}^{\prime}\sinh\eta+x_{1}^{\prime}\cosh\eta & & =\frac{x_{1}^{\prime}+x_{0}^{\prime}\tanh\eta}{\sqrt{1-\tanh^{2}\eta}} & & =\frac{x_{1}^{\prime}+x_{0}^{\prime}v}{\sqrt{1-v^{2}}} \end{align} \right|{\scriptstyle \begin{align}\sinh^{2}\eta-\cosh^{2}\eta & =-1 & (a)\\ \cosh^{2}\eta-\sinh^{2}\eta & =1 & (b)\\ \frac{\sinh\eta}{\cosh\eta} & =\tanh\eta=v & (c)\\ \frac{1}{\sqrt{1-\tanh^{2}\eta}} & =\cosh\eta & (d)\\ \frac{\tanh\eta}{\sqrt{1-\tanh^{2}\eta}} & =\sinh\eta & (e)\\ \frac{\tanh q\pm\tanh\eta}{1\pm\tanh q\tanh\eta} & =\tanh\left(q\pm\eta\right) & (f) \end{align} } \end{matrix}</math> or in matrix notation <math>\left.\begin{align}\mathbf{x}' & =\begin{bmatrix}\cosh\eta & -\sinh\eta\\ -\sinh\eta & \cosh\eta \end{bmatrix}\cdot\mathbf{x}\\ \mathbf{x} & =\begin{bmatrix}\cosh\eta & \sinh\eta\\ \sinh\eta & \cosh\eta \end{bmatrix}\cdot\mathbf{x}' \end{align} \quad\right|\quad\det\begin{bmatrix}\cosh\eta & -\sinh\eta\\ -\sinh\eta & \cosh\eta \end{bmatrix}=1</math>|{{equationRef|3b}}}} Hyperbolic identities (a,b) on the right of ({{equationNote|3b}}) were given by [[#Riccati|Riccati (1757)]], all identities (a,b,c,d,e,f) by [[#Lambert|Lambert (1768–1770)]]. Lorentz transformations ({{equationNote|3b}}-A) were given by [[#Laisant|Laisant (1874)]], [[#Cox|Cox (1882)]], [[#Lindemann|Lindemann (1890/91)]], [[#Gerard|Gérard (1892)]], [[#Killing2|Killing (1893, 1897/98)]], [[#Whitehead|Whitehead (1897/98)]], [[#Woods2|Woods (1903/05)]], [[#Elliott|Elliott (1903)]] and [[#Liebmann|Liebmann (1904/05)]] in terms of Weierstrass coordinates of the [[w:hyperboloid model]], while transformations similar to ({{equationNote|3b}}-C) have been used by [[#Lipschitz1|Lipschitz (1885/86)]]. In special relativity, hyperbolic functions were used by [[#Frank|Frank (1909)]] and [[#Varicak|Varićak (1910)]]. Rapidity can be composed of arbitrary many rapidities <math>\eta_{1},\eta_{2}\dots</math> as per the [[w:Hyperbolic functions#Sums of arguments|w:angle sum laws of hyperbolic sines and cosines]], so that one hyperbolic rotation can represent the sum of many other hyperbolic rotations, analogous to the relation between [[w:List of trigonometric identities#Angle sum and difference identities|w:angle sum laws of circular trigonometry]] and spatial rotations. Alternatively, the hyperbolic angle sum laws ''themselves'' can be interpreted as Lorentz boosts, as demonstrated by using the parameterization of the [[w:unit hyperbola]]: {{NumBlk|:|<math>\begin{matrix}-x_{0}^{2}+x_{1}^{2}=-x_{0}^{\prime2}+x_{1}^{\prime2}=1\\ \hline \left[\eta=\eta_{2}-\eta_{1}\right]\\ \begin{align}x_{0}^{\prime} & =\sinh\eta_{1}=\sinh\left(\eta_{2}-\eta\right)=\sinh\eta_{2}\cosh\eta-\cosh\eta_{2}\sinh\eta & & =x_{0}\cosh\eta-x_{1}\sinh\eta\\ x_{1}^{\prime} & =\cosh\eta_{1}=\cosh\left(\eta_{2}-\eta\right)=-\sinh\eta_{2}\sinh\eta+\cosh\eta_{2}\cosh\eta & & =-x_{0}\sinh\eta+x_{1}\cosh\eta\\ \\ x_{0} & =\sinh\eta_{2}=\sinh\left(\eta_{1}+\eta\right)=\sinh\eta_{1}\cosh\eta+\cosh\eta_{1}\sinh\eta & & =x_{0}^{\prime}\cosh\eta+x_{1}^{\prime}\sinh\eta\\ x_{1} & =\cosh\eta_{2}=\cosh\left(\eta_{1}+\eta\right)=\sinh\eta_{1}\sinh\eta+\cosh\eta_{1}\cosh\eta & & =x_{0}^{\prime}\sinh\eta+x_{1}^{\prime}\cosh\eta \end{align} \end{matrix}</math> or in matrix notation <math>{\scriptstyle \begin{align}\begin{bmatrix}x_{1}^{\prime} & x_{0}^{\prime}\\ x_{0}^{\prime} & x_{1}^{\prime} \end{bmatrix} & =\begin{bmatrix}\cosh\eta_{1} & \sinh\eta_{1}\\ \sinh\eta_{1} & \cosh\eta_{1} \end{bmatrix}=\begin{bmatrix}\cosh\left(\eta_{2}-\eta\right) & \sinh\left(\eta_{2}-\eta\right)\\ \sinh\left(\eta_{2}-\eta\right) & \cosh\left(\eta_{2}-\eta\right) \end{bmatrix}=\begin{bmatrix}\cosh\eta_{2} & \sinh\eta_{2}\\ \sinh\eta_{2} & \cosh\eta_{2} \end{bmatrix}\cdot\begin{bmatrix}\cosh\eta & -\sinh\eta\\ -\sinh\eta & \cosh\eta \end{bmatrix} & & =\begin{bmatrix}x_{1} & x_{0}\\ x_{0} & x_{1} \end{bmatrix}\cdot\begin{bmatrix}\cosh\eta & -\sinh\eta\\ -\sinh\eta & \cosh\eta \end{bmatrix}\\ \begin{bmatrix}x_{1} & x_{0}\\ x_{0} & x_{1} \end{bmatrix} & =\begin{bmatrix}\cosh\eta_{2} & \sinh\eta_{2}\\ \sinh\eta_{2} & \cosh\eta_{2} \end{bmatrix}=\begin{bmatrix}\cosh\left(\eta_{1}+\eta\right) & \sinh\left(\eta_{1}+\eta\right)\\ \sinh\left(\eta_{1}+\eta\right) & \cosh\left(\eta_{1}+\eta\right) \end{bmatrix}=\begin{bmatrix}\cosh\eta_{1} & \sinh\eta_{1}\\ \sinh\eta_{1} & \cosh\eta_{1} \end{bmatrix}\cdot\begin{bmatrix}\cosh\eta & \sinh\eta\\ \sinh\eta & \cosh\eta \end{bmatrix} & & =\begin{bmatrix}x_{1}^{\prime} & x_{0}^{\prime}\\ x_{0}^{\prime} & x_{1}^{\prime} \end{bmatrix}\cdot\begin{bmatrix}\cosh\eta & \sinh\eta\\ \sinh\eta & \cosh\eta \end{bmatrix} \end{align} }</math>|{{equationRef|3c}}}} Hyperbolic angle sum laws were given by [[#Riccati|Riccati (1757)]] and [[#Lambert|Lambert (1768–1770)]] and many others, while matrix representations were given by [[#Glaisher|Glaisher (1878)]] and [[#Gunther1|Günther (1880/81)]]. Using the idendity <math>\cosh\eta+\sinh\eta=e^{\eta}</math>, Lorentz boost ({{equationNote|3b}}) assumes a simple form by using [[w:squeeze mapping]]s in analogy to Euler's formula in [[../Lorentz transformation (imaginary)#math_2c|E:'''(2c)''']]:<ref name=rind>Rindler (1969), p. 45</ref> {{NumBlk|:|<math>\begin{matrix}-x_{0}^{2}+x_{1}^{2}=-x_{0}^{\prime2}+x_{1}^{\prime2}\\ \hline \begin{matrix}\begin{aligned}x_{1}^{\prime}-x_{0}^{\prime} & =k\left(x_{1}-x_{0}\right)\\ x_{1}^{\prime}+x_{0}^{\prime} & =\frac{1}{k}\left(x_{1}+x_{0}\right) \end{aligned} & \Rightarrow & \begin{aligned}x_{1}^{\prime}-x_{0}^{\prime} & =e^{\eta}\left(x_{1}-x_{0}\right)\\ x_{1}^{\prime}+x_{0}^{\prime} & =e^{-\eta}\left(x_{1}+x_{0}\right) \end{aligned} \end{matrix}\\ \hline k=e^{\eta}=\cosh\eta+\sinh\eta=\sqrt{\frac{1+\tanh\eta}{1-\tanh\eta}}=\sqrt{\frac{1+v}{1-v}} \end{matrix}</math>|{{equationRef|3d}}}} Lorentz transformations ({{equationNote|3d}}) for arbitrary ''k'' were given by many authors (see [[../Lorentz transformation (squeeze)|E:Lorentz transformations via squeeze mappings]]), while a form similar to <math>k=\sqrt{\tfrac{1+v}{1-v}}</math> was given by [[#Lipschitz1|Lipschitz (1885/86)]], and the exponential form was used by [[#Lindemann|Lindemann (1890/91)]], [[#Elliott|Elliott (1903)]], [[#Herglotz1|Herglotz (1909)]]. ===Hyperbolic law of cosines=== In line with equation [[../Lorentz transformation (general)#math_1b|E:'''(1b)''']] one can use coordinates <math>[u_{1},\ u_{2}]=\left[\tfrac{x_{1}}{x_{0}},\ \tfrac{x_{2}}{x_{0}}\right]</math> inside the [[w:unit circle]] <math>u_{1}^{2}+u_{2}^{2}=1</math>, thus the corresponding Lorentz transformations ({{equationNote|3b}}) obtain the form: {{NumBlk|:|<math>\begin{align} & \quad\quad(A) & & \quad\quad(B) & & \quad\quad(C)\\ u_{1}^{\prime} & =\frac{-\sinh\eta+u_{1}\cosh\eta}{\cosh\eta-u_{1}\sinh\eta} & & =\frac{u_{1}-\tanh\eta}{1-u_{1}\tanh\eta} & & =\frac{u_{1}-v}{1-u_{1}v}\\ u_{2}^{\prime} & =\frac{u_{2}}{\cosh\eta-u_{1}\sinh\eta} & & =\frac{u_{2}\sqrt{1-\tanh^{2}\eta}}{1-u_{1}\tanh\eta} & & =\frac{u_{2}\sqrt{1-v^{2}}}{1-u_{1}v}\\ \\ u_{1} & =\frac{\sinh\eta+u_{1}^{\prime}\cosh\eta}{\cosh\eta+u_{1}^{\prime}\sinh\eta} & & =\frac{u_{1}^{\prime}+\tanh\eta}{1+u_{1}^{\prime}\tanh\eta} & & =\frac{u_{1}^{\prime}+v}{1+u_{1}^{\prime}v}\\ u_{2} & =\frac{u_{2}^{\prime}}{\cosh\eta+u_{1}^{\prime}\sinh\eta} & & =\frac{u_{2}^{\prime}\sqrt{1-\tanh^{2}\eta}}{1+u_{1}^{\prime}\tanh\eta} & & =\frac{u_{2}^{\prime}\sqrt{1-v^{2}}}{1+u_{1}^{\prime}v} \end{align} </math>|{{equationRef|3e}}}} Transformations (A) were given by [[#Escherich|Escherich (1874)]] and [[#Killing2|Killing (1898)]], and transformations (C) by [[#Beltrami|Beltrami (1868)]] and [[#Schur|Schur (1885/86, 1900/02)]] in terms of [[w:Beltrami–Klein model|Beltrami coordinates]]<ref>Rosenfeld (1988), p. 231</ref> of hyperbolic geometry. By using the scalar product of <math>\left[u_{1},u_{2}\right]</math>, the resulting Lorentz transformation can be seen as equivalent to the [[w:hyperbolic law of cosines]]:<ref name=pau>Pauli (1921), p. 561</ref><ref group=R name=var>Varićak (1912), p. 108</ref><ref name=barr>Barrett (2006), chapter 4, section 2</ref> {{NumBlk|:|<math>\begin{matrix} & \begin{matrix}u^{2}=u_{1}^{2}+u_{2}^{2}\\ u'^{2}=u_{1}^{\prime2}+u_{2}^{\prime2} \end{matrix}\left|\begin{matrix}u_{1}=u\cos\alpha\\ u_{2}=u\sin\alpha\\ \\ u_{1}^{\prime}=u'\cos\alpha'\\ u_{2}^{\prime}=u'\sin\alpha' \end{matrix}\right|\begin{align}u\cos\alpha & =\frac{u'\cos\alpha'+v}{1+vu'\cos\alpha'}, & u'\cos\alpha' & =\frac{u\cos\alpha-v}{1-vu\cos\alpha}\\ u\sin\alpha & =\frac{u'\sin\alpha'\sqrt{1-v^{2}}}{1+vu'\cos\alpha'}, & u'\sin\alpha' & =\frac{u\sin\alpha\sqrt{1-v^{2}}}{1-vu\cos\alpha}\\ \tan\alpha & =\frac{u'\sin\alpha'\sqrt{1-v^{2}}}{u'\cos\alpha'+v}, & \tan\alpha' & =\frac{u\sin\alpha\sqrt{1-v^{2}}}{u\cos\alpha-v} \end{align} \\ \Rightarrow & u=\frac{\sqrt{v^{2}+u^{\prime2}+2vu'\cos\alpha'-\left(vu'\sin\alpha'\right){}^{2}}}{1+vu'\cos\alpha'},\quad u'=\frac{\sqrt{-v^{2}-u^{2}+2vu\cos\alpha+\left(vu\sin\alpha\right){}^{2}}}{1-vu\cos\alpha}\\ \Rightarrow & \frac{1}{\sqrt{1-u^{\prime2}}}=\frac{1}{\sqrt{1-v^{2}}}\frac{1}{\sqrt{1-u^{2}}}-\frac{v}{\sqrt{1-v^{2}}}\frac{u}{\sqrt{1-u^{2}}}\cos\alpha & (b)\\ \Rightarrow & \frac{1}{\sqrt{1-\tanh^{2}\xi}}=\frac{1}{\sqrt{1-\tanh^{2}\eta}}\frac{1}{\sqrt{1-\tanh^{2}\zeta}}-\frac{\tanh\eta}{\sqrt{1-\tanh^{2}\eta}}\frac{\tanh\zeta}{\sqrt{1-\tanh^{2}\zeta}}\cos\alpha\\ \Rightarrow & \cosh\xi=\cosh\eta\cosh\zeta-\sinh\eta\sinh\zeta\cos\alpha & (a) \end{matrix}</math>|{{equationRef|3f}}}} The hyperbolic law of cosines (a) was given by [[#Taurinus|Taurinus (1826) and Lobachevsky (1829/30)]] and others, while variant (b) was given by [[#Schur|Schur (1900/02)]]. By further setting ''u=u′'' it follows: {{NumBlk|:|<math>\begin{matrix}\cos\alpha=\frac{\cos\alpha'+v}{1+v\cos\alpha'},\ \sin\alpha=\frac{\sin\alpha'\sqrt{1-v^{2}}}{1+v\cos\alpha'},\ \tan\alpha=\frac{\sin\alpha'\sqrt{1-v^{2}}}{\cos\alpha'+v},\ \tan\frac{\alpha}{2}=\sqrt{\frac{1-v}{1+v}}\tan\frac{\alpha'}{2}\\ \cos\alpha'=\frac{\cos\alpha-v}{1-v\cos\alpha},\ \sin\alpha'=\frac{\sin\alpha\sqrt{1-v^{2}}}{1-v\cos\alpha},\ \tan\alpha'=\frac{\sin\alpha\sqrt{1-v^{2}}}{\cos\alpha-v},\ \tan\frac{\alpha'}{2}=\sqrt{\frac{1+v}{1-v}}\tan\frac{\alpha}{2} \end{matrix}</math>|{{equationRef|3g}}}} Formulas (3g) resemble the equations of an [[w:ellipse]] of [[w:Orbital eccentricity|eccentricity]] ''v/c'', [[w:eccentric anomaly]] α' and [[w:true anomaly]] α, first geometrically formulated by [[#Euler|Kepler (1609)]] and explicitly written down by [[#Euler|Euler (1735, 1748), Lagrange (1770)]] and many others in relation to planetary motions. They were also used by [[../Lorentz transformation (conformal)#Darboux|E:Darboux (1873)]] as a sphere transformation. In special relativity, these formulas describes the aberration of light, see [[../Lorentz transformation (velocity)#Velocity addition and aberration|E:velocity addition and aberration]]. ==Historical notation== ==={{anchor|Euler}} Euler (1735) – True and eccentric anomaly=== [[w:Johannes Kepler]] (1609) geometrically formulated [[w:Kepler's equation]] and the relations between the [[w:mean anomaly]], [[w:true anomaly]], and [[w:eccentric anomaly]].<ref group=M>Kepler (1609), chapter 60. The editors of Kepler's collected papers remark (p. 482), that Kepler's relations correspond to <math>{\scriptstyle \alpha=\beta+e\sin\beta}</math> and <math>{\scriptstyle \cos\nu=\frac{e+\cos\beta}{1+e\cos\beta}}</math> and <math>{\scriptstyle \cos\beta=\frac{\cos\nu-e}{1-e\cos\nu}}</math></ref><ref>Volk (1976), p. 366</ref> The relation between the true anomaly ''z'' and the eccentric anomaly ''P'' was algebraically expressed by [[w:Leonhard Euler]] (1735/40) as follows:<ref group=M>Euler (1735/40), § 19</ref> :<math>\cos z=\frac{\cos P+v}{1+v\cos P},\ \cos P=\frac{\cos z-v}{1-v\cos z},\ \int P=\frac{\int z\sqrt{1-v^{2}}}{1-v\cos z}</math> and in 1748:<ref group=M>Euler (1748a), section VIII</ref> :<math>\cos z=\frac{n+\cos y}{1+n\cos y},\ \sin z=\frac{\sin y\sqrt{1-n^{2}}}{1+n\cos y},\ \tan z=\frac{\sin y\sqrt{1-n^{2}}}{n+\cos y}</math> while [[w:Joseph-Louis Lagrange]] (1770/71) expressed them as follows<ref group=M>Lagrange (1770/71), section I</ref> :<math>\sin u=\frac{m\sin x}{1+n\cos x},\ \cos u=\frac{n+\cos x}{1+n\cos x},\ \operatorname{tang}\frac{1}{2}u=\frac{m}{1+n}\operatorname{tang}\frac{1}{2}x,\ \left(m^{2}=1-n^{2}\right)</math> <p style="background-color:Beige;border:1px solid black"> These relations resemble formulas ({{equationNote|3g}}), while ({{equationNote|3f}}) follows by setting <math>[\cos z,\sin z]=\left[u_{x},u_{y}\right]</math> in Euler's formulas or <math>[\cos u,\sin u]=\left[u_{x},u_{y}\right]</math> in Lagrange's formulas.</p> ==={{anchor|Riccati}} Riccati (1757) – hyperbolic addition=== [[w:Vincenzo Riccati]] introduced hyperbolic functions in 1757,<ref group=M>Riccati (1757), p. 71</ref><ref group=M>Günther (1880/81), pp. 7–13</ref> in particular he formulated the angle sum laws for hyperbolic sine and cosine: :<math>\begin{matrix}\mathrm{Ch}(\varphi+\pi)=\frac{\mathrm{Ch}\varphi\mathrm{Ch}\pi+\mathrm{Sh}\varphi\mathrm{Sh}\pi}{r}\\ \mathrm{Sh}(\varphi+\pi)=\frac{\mathrm{Ch}\varphi\mathrm{Sh}\pi+\mathrm{Ch}\pi\mathrm{Sh}\varphi}{r}\\ \left[\mathrm{Ch}^{2}-\mathrm{Sh}^{2}=rr\right] \end{matrix}</math> He furthermore showed that <math>\mathrm{Ch}(\varphi-\pi)</math> and <math>\mathrm{Sh}(\varphi-\pi)</math> follow by setting <math>\mathrm{Ch}(\pi)\Rightarrow\mathrm{Ch}(-\pi)</math> and <math>\mathrm{Sh}(\pi)\Rightarrow\mathrm{Sh}(-\pi)</math> in the above formulas. <p style="background-color:Beige;border:1px solid black">The angle sum laws for hyperbolic sine and cosine can be interpreted as hyperbolic rotations of points on a hyperbola, as in Lorentz boost ({{equationNote|3c}}). (In modern publications, Riccati's additional factor ''r'' is set to unity.)</p> ==={{anchor|Lambert}} Lambert (1768–1770) – hyperbolic addition=== While [[#Riccati|Riccati (1757)]] discussed the hyperbolic sine and cosine, [[w:Johann Heinrich Lambert]] (read 1767, published 1768) introduced the expression ''tang φ'' or abbreviated ''tφ'' as the [[w:tangens hyperbolicus]] <math>{\scriptstyle \frac{e^{u}-e^{-u}}{e^{u}+e^{-u}}}</math> of a variable ''u'', or in modern notation ''tφ=tanh(u)'':<ref group=M>Lambert (1761/68), pp. 309–318</ref><ref>Barnett (2004), pp. 22–23</ref> :<math>\left.\begin{align}\xi\xi-1 & =\eta\eta & (a)\\ 1+\eta\eta & =\xi\xi & (b)\\ \frac{\eta}{\xi} & =tang\ \phi=t\phi & (c)\\ \xi & =\frac{1}{\sqrt{1-t\phi^{2}}} & (d)\\ \eta & =\frac{t\phi}{\sqrt{1-t\phi^{2}}} & (e)\\ t\phi'' & =\frac{t\phi+t\phi'}{1+t\phi\cdot t\phi'} & (f)\\ t\phi' & =\frac{t\phi''-t\phi}{1-t\phi\cdot t\phi''} & (g) \end{align} \right|\begin{align}2u & =\log\frac{1+t\phi}{1-t\phi}\\ \xi & =\frac{e^{u}+e^{-u}}{2}\\ \eta & =\frac{e^{u}-e^{-u}}{2}\\ t\phi & =\frac{e^{u}-e^{-u}}{e^{u}+e^{-u}}\\ e^{u} & =\xi+\eta\\ e^{-u} & =\xi-\eta \end{align}</math> In (1770) he rewrote the addition law for the hyperbolic tangens (f) or (g) as:<ref group=M>Lambert (1770), p. 335</ref> :<math>\begin{align}t(y+z) & =(ty+tz):(1+ty\cdot tz) & (f)\\ t(y-z) & =(ty-tz):(1-ty\cdot tz) & (g) \end{align} </math> <p style="background-color:Beige;border:1px solid black">The hyperbolic relations (a,b,c,d,e,f) are equivalent to the hyperbolic relations on the right of ({{equationNote|3b}}). Relations (f,g) can also be found in ({{equationNote|3e}}). By setting ''tφ=v/c'', formula (c) becomes the relative velocity between two frames, (d) the [[w:Lorentz factor]], (e) the [[w:proper velocity]], (f) or (g) becomes the Lorentz transformation of velocity (or relativistic [[w:velocity addition formula]]) for collinear velocities in [[../Lorentz transformation (velocity)#math_4a|E:'''(4a)''']] and [[../Lorentz transformation (velocity)#math_4d|E:'''(4d)''']].</p> Lambert also formulated the addition laws for the hyperbolic cosine and sine (Lambert's "cos" and "sin" actually mean "cosh" and "sinh"): :<math>\begin{align}\sin(y+z) & =\sin y\cos z+\cos y\sin z\\ \sin(y-z) & =\sin y\cos z-\cos y\sin z\\ \cos(y+z) & =\cos y\cos z+\sin y\sin z\\ \cos(y-z) & =\cos y\cos z-\sin y\sin z \end{align} </math> <p style="background-color:Beige;border:1px solid black">The angle sum laws for hyperbolic sine and cosine can be interpreted as hyperbolic rotations of points on a hyperbola, as in Lorentz boost ({{equationNote|3c}}).</p> ==={{Anchor|Taurinus}} Taurinus (1826) – Hyperbolic law of cosines=== After the addition theorem for the tangens hyperbolicus was given by [[#Lambert|Lambert (1768)]], [[w:hyperbolic geometry]] was used by [[w:Franz Taurinus]] (1826), and later by [[w:Nikolai Lobachevsky]] (1829/30) and others, to formulate the [[w:hyperbolic law of cosines]]:<ref group=M>Taurinus (1826), p. 66; see also p. 272 in the translation by Engel and Stäckel (1899)</ref><ref>Bonola (1912), p. 79</ref><ref>Gray (1979), p. 242</ref> :<math>A=\operatorname{arccos}\frac{\cos\left(\alpha\sqrt{-1}\right)-\cos\left(\beta\sqrt{-1}\right)\cos\left(\gamma\sqrt{-1}\right)}{\sin\left(\beta\sqrt{-1}\right)\sin\left(\gamma\sqrt{-1}\right)}</math> <p style="background-color:Beige;border:1px solid black">When solved for <math>\cos\left(\alpha\sqrt{-1}\right)</math> it corresponds to the Lorentz transformation in Beltrami coordinates ({{equationNote|3f}}), and by defining the rapidities <math>{\scriptstyle \left(\left[\frac{U}{c},\ \frac{v}{c},\ \frac{u}{c}\right]=\left[\tanh\alpha,\ \tanh\beta,\ \tanh\gamma\right]\right)}</math> it corresponds to the relativistic velocity addition formula [[../Lorentz transformation (velocity)#math_4e|E:'''(4e)''']].</p> ==={{anchor|Beltrami}} Beltrami (1868) – Beltrami coordinates=== [[w:Eugenio Beltrami]] (1868a) introduced coordinates of the [[w:Beltrami–Klein model]] of hyperbolic geometry, and formulated the corresponding transformations in terms of homographies:<ref group=M>Beltrami (1868a), pp. 287-288; Note I; Note II</ref> :<math>\begin{matrix}ds^{2}=R^{2}\frac{\left(a^{2}+v^{2}\right)du^{2}-2uv\,du\,dv+\left(a^{2}+v^{2}\right)dv^{2}}{\left(a^{2}+u^{2}+v^{2}\right)^{2}}\\ u^{2}+v^{2}=a^{2}\\ \hline u''=\frac{aa_{0}\left(u'-r_{0}\right)}{a^{2}-r_{0}u'},\ v''=\frac{a_{0}w_{0}v'}{a^{2}-r_{0}u'},\\ \left(r_{0}=\sqrt{u_{0}^{2}+v_{0}^{2}},\ w_{0}=\sqrt{a^{2}-r_{0}^{2}}\right)\\ \hline ds^{2}=R^{2}\frac{\left(a^{2}-v^{2}\right)du^{2}+2uv\,du\,dv+\left(a^{2}-v^{2}\right)dv^{2}}{\left(a^{2}-u^{2}-v^{2}\right)^{2}}\\ (R=R\sqrt{-1},\ a=a\sqrt{-1}) \end{matrix}</math> (where the disk radius ''a'' and the [[w:radius of curvature]] ''R'' are real in spherical geometry, in hyperbolic geometry they are imaginary), and for arbitrary dimensions in (1868b)<ref group=M>Beltrami (1868b), pp. 232, 240–241, 253–254</ref> :<math>\begin{matrix}ds=R\frac{\sqrt{dx^{2}+dx_{1}^{2}+dx_{2}^{2}+\cdots+dx_{n}^{2}}}{x}\\ x^{2}+x_{1}^{2}+x_{2}^{2}+\cdots+x_{n}^{2}=a^{2}\\ \hline y_{1}=\frac{ab\left(x_{1}-a_{1}\right)}{a^{2}-a_{1}x_{1}}\ \text{or}\ x_{1}=\frac{a\left(ay_{1}+a_{1}b\right)}{ab+a_{1}y_{1}},\ x_{r}=\pm\frac{ay_{r}\sqrt{a^{2}-a_{1}^{2}}}{ab+a_{1}y_{1}}\ (r=2,3,\dots,n)\\ \hline ds=R\frac{\sqrt{dx_{1}^{2}+dx_{2}^{2}+\cdots+dx_{n}^{2}-dx^{2}}}{x}\\ x^{2}=a^{2}+x_{1}^{2}+x_{2}^{2}+\cdots+x_{n}^{2}\\ \left(R=R\sqrt{-1},\ x=x\sqrt{-1},\ a=a\sqrt{-1}\right) \end{matrix}</math> <p style="background-color:Beige;border:1px solid black">Setting ''a=a₀'' Beltrami's (1868a) formulas become formulas ({{equationNote|3e}}), or in his (1868b) formulas one sets ''a=b'' for arbitrary dimensions.</p> === {{anchor|Laisant2}} Laisant (1874) – Equipollences=== In his French translation of [[w:Giusto Bellavitis]]' principal work on [[w:Equipollence (geometry)|w:equipollences]], [[w:Charles-Ange Laisant]] (1874) added a chapter related to hyperbolas. The equipollence OM and its tangent MT of a hyperbola is defined by Laisant as<ref group=M>Laisant (1874b), pp. 134–135</ref> :(1) <math>\begin{matrix} & \mathrm{OM}\bumpeq x\mathrm{OA}+y\mathrm{OB}\\ & \mathrm{MT}\bumpeq y\mathrm{OA}+x\mathrm{OB}\\ & \left[x^{2}-y^{2}=1;\ x=\cosh t,\ y=\sinh t\right]\\ \Rightarrow & \mathrm{OM}\bumpeq\cosh t\cdot\mathrm{OA}+\sinh t\cdot\mathrm{OB} \end{matrix}</math> Here, OA and OB are [[w:Conjugate diameters|conjugate semi-diameters]] of a hyperbola with OB being imaginary, both of which he related to two other conjugated semi-diameters OC and OD by the following transformation: :<math>\begin{matrix}\begin{align}\mathrm{OC} & \bumpeq c\mathrm{OA}+d\mathrm{OB} & \qquad & & \mathrm{OA} & \bumpeq c\mathrm{OC}-d\mathrm{OD}\\ \mathrm{OD} & \bumpeq d\mathrm{OA}+c\mathrm{OB} & & & \mathrm{OB} & \bumpeq-d\mathrm{OC}+c\mathrm{OD} \end{align} \\ \left[c^{2}-d^{2}=1\right] \end{matrix}</math> producing the invariant relation :<math>(\mathrm{OC})^{2}-(\mathrm{OD})^{2}\bumpeq(\mathrm{OA})^{2}-(\mathrm{OB})^{2}</math>. Substituting into (1), he showed that OM retains its form :<math>\begin{matrix}\mathrm{OM}\bumpeq(cx-dy)\mathrm{OC}+(cy-dx)\mathrm{OD}\\ \left[(cx-dy)^{2}-(cy-dx)^{2}=1\right] \end{matrix}</math> He also defined velocity and acceleration by differentiation of (1). <p style="background-color:Beige;border:1px solid black">These relations are equivalent to several Lorentz boosts or hyperbolic rotations producing the invariant Lorentz interval in line with ({{equationNote|3b}}).</p> ==={{anchor|Escherich}} Escherich (1874) – Beltrami coordinates=== [[w:Gustav von Escherich]] (1874) discussed the plane of constant negative curvature<ref>Sommerville (1911), p. 297</ref> based on the [[w:Beltrami–Klein model]] of hyperbolic geometry by [[#Beltrami|Beltrami (1868)]]. Similar to [[w:Christoph Gudermann]] (1830)<ref name=guder group=M>Gudermann (1830), §1–3, §18–19</ref> who introduced axial coordinates ''x''=tan(a) and ''y''=tan(b) in sphere geometry in order to perform coordinate transformations in the case of rotation and translation, Escherich used hyperbolic functions ''x''=tanh(a/k) and ''y''=tanh(b/k)<ref group=M>Escherich (1874), p. 508</ref> in order to give the corresponding coordinate transformations for the hyperbolic plane, which for the case of translation have the form:<ref group=M name=escher>Escherich (1874), p. 510</ref> :<math>x=\frac{\sinh\frac{a}{k}+x'\cosh\frac{a}{k}}{\cosh\frac{a}{k}+x'\sinh\frac{a}{k}}</math> and <math>y=\frac{y'}{\cosh\frac{a}{k}+x'\sinh\frac{a}{k}}</math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Lorentz transformation ({{equationNote|3e}}), also equivalent to the relativistic velocity addition [[../Lorentz transformation (velocity)#math_4d|E:'''(4d)''']] by setting <math>\tfrac{a}{k}=\operatorname{atanh}\tfrac{v}{c}</math> and multiplying ''[x,y,x′,y′]'' by 1/''c'', and equivalent to Lorentz boost ({{equationNote|3b}}) by setting <math>\scriptstyle (x,\ y,\ x',\ y')=\left(\frac{x_{1}}{x_{0}},\ \frac{x_{2}}{x_{0}},\ \frac{x_{1}^{\prime}}{x_{0}^{\prime}},\ \frac{x_{2}^{\prime}}{x_{0}^{\prime}}\right)</math>. This is the relation between the [[w:Beltrami–Klein model|Beltrami coordinates]] in terms of Gudermann-Escherich coordinates, and the Weierstrass coordinates of the [[w:hyperboloid model]] introduced by [[../Lorentz transformation (general)#Killing1|E:Killing (1878–1893)]], [[../Lorentz transformation (general)#Poincare|E:Poincaré (1881)]], and [[../Lorentz transformation (general)#Cox|E:Cox (1881)]]. Both coordinate systems were compared by Cox (1881).<ref group=M>Cox (1881), p. 186</ref></p> ==={{anchor|Glaisher}} Glaisher (1878) – hyperbolic addition=== It was shown by [[w:James Whitbread Lee Glaisher]] (1878) that the hyperbolic addition laws can be expressed by matrix multiplication:<ref group=M>Glaisher (1878), p. 30</ref> :<math>\begin{matrix}\begin{vmatrix}\cosh x, & \sinh x\\ \sinh x, & \cosh x \end{vmatrix}=1,\ \begin{vmatrix}\cosh y, & \sinh y\\ \sinh y, & \cosh y \end{vmatrix}=1\\ \text{by multiplication:}\\ \Rightarrow\begin{vmatrix}c_{1}c_{2}+s_{1}s_{2}, & s_{1}c_{2}+c_{1}s_{2}\\ c_{1}s_{2}+s_{1}c_{2}, & s_{1}s_{2}+c_{1}c_{2} \end{vmatrix}=1\\ \text{where}\ \left[c_{1},c_{2},c_{3},c_{4}\right]=\left[\cosh x,\cosh y,\sinh x,\sinh y\right] \\ \Rightarrow\begin{vmatrix}\cosh(x+y), & \sinh(x+y)\\ \sinh(x+y), & \cosh(x+y) \end{vmatrix}=1 \end{matrix}</math> <p style="background-color:Beige;border:1px solid black">In this matrix representation, the analogy between the hyperbolic angle sum laws and the Lorentz boost becomes obvious: In particular, the matrix <math>\scriptstyle\begin{vmatrix}\cosh y, & \sinh y\\ \sinh y, & \cosh y\end{vmatrix}</math> producing the hyperbolic addition is analogous to matrix <math>\scriptstyle\begin{bmatrix}\cosh\eta & \sinh\eta\\ \sinh\eta & \cosh\eta\end{bmatrix}</math> producing Lorentz boost ({{equationNote|3b}}) and ({{equationNote|3c}}).</p> ==={{anchor|Gunther1}} Günther (1880/81) – hyperbolic addition === Following [[#Glaisher|Glaisher (1878)]], [[w:Siegmund Günther]] (1880/81) expressed the hyperbolic addition laws by matrix multiplication:<ref group=M>Günther (1880/81), p. 405</ref> :<math>\begin{matrix}\begin{vmatrix}\mathfrak{Cos}\,x, & \mathfrak{Sin}\,x\\ \mathfrak{Sin}\,x, & \mathfrak{Cos}\,x \end{vmatrix}\cdot\begin{vmatrix}\mathfrak{Cos}\,y, & \mathfrak{Sin}\,y\\ \mathfrak{Sin}\,y, & \mathfrak{Cos}\,y \end{vmatrix}\\ =\begin{vmatrix}\mathfrak{Cos}\,x\,\mathfrak{Cos}\,y+\mathfrak{Sin}\,x\,\mathfrak{Sin}\,y, & \mathfrak{Cos}\,x\,\mathfrak{Sin}\,y+\mathfrak{Sin}\,x\,\mathfrak{Cos}\,y\\ \mathfrak{Sin}\,x\,\mathfrak{Cos}\,y+\mathfrak{Cos}\,x\,\mathfrak{Sin}\,y, & \mathfrak{Sin}\,x\,\mathfrak{Sin}\,y+\mathfrak{Cos}\,x\,\mathfrak{Cos}\,y \end{vmatrix}\\ =\begin{vmatrix}\mathfrak{Cos}\,(x+y), & \mathfrak{Sin}\,(x+y)\\ \mathfrak{Sin}\,(x+y), & \mathfrak{Cos}\,(x+y) \end{vmatrix}=1 \end{matrix}</math> <p style="background-color:Beige;border:1px solid black">In this matrix representation, the analogy between the hyperbolic angle sum laws and the Lorentz boost becomes obvious: In particular, the matrix <math>\scriptstyle\begin{vmatrix}\mathfrak{Cos}\,y, & \mathfrak{Sin}\,y\\ \mathfrak{Sin}\,y, & \mathfrak{Cos}\,y \end{vmatrix}</math> producing the hyperbolic addition is analogous to matrix <math>\scriptstyle\begin{bmatrix}\cosh\eta & \sinh\eta\\ \sinh\eta & \cosh\eta\end{bmatrix}</math> producing Lorentz boost ({{equationNote|3b}}) and ({{equationNote|3c}}).</p> === {{anchor|Cox}} Cox (1881/82) – Weierstrass coordinates === [[w:Homersham Cox (mathematician)|w:Homersham Cox]] (1881/82) defined the case of translation in the hyperbolic plane with the ''y''-axis remaining unchanged:<ref group=M name=cox>Cox (1881/82), p. 194</ref> :<math>\begin{align}X & =x\cosh p-z\sinh p\\ Z & =-x\sinh p+z\cosh p \\ \\ x & =X\cosh p+Z\sinh p\\ z & =X\sinh p+Z\cosh p \end{align} </math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Lorentz boost ({{equationNote|3b}}).</p> ==={{anchor|Lipschitz1}} Lipschitz (1885/86) === [[w:Rudolf Lipschitz]] (1885/86) formulated transformations leaving invariant the sum of squares <math>x_{1}^{2}+x_{2}^{2}\dots+x_{n}^{2}=y_{1}^{2}+y_{2}^{2}+\dots+y_{n}^{2}</math>, which he rewrote as <math>x_{1}^{2}-y_{1}^{2}+x_{2}^{2}-y_{2}^{2}+\dots+x_{n}^{2}-y_{n}^{2}=0</math>. This led to the problem of finding transformations leaving invariant the pairs <math>x_{a}^{2}-y_{a}^{2}</math> (''a''=1...n) for which he gave the following solution:<ref group=M>Lipschitz (1886), pp. 90–92</ref> :<math>\begin{matrix}x_{a}^{2}-y_{a}^{2}=\mathfrak{x}_{a}^{2}-\mathfrak{y}_{a}^{2}\\ \hline \begin{align}x_{a}-y_{a} & =\left(\mathfrak{x}_{a}-\mathfrak{y}_{a}\right)r_{a}\\ x_{a}+y_{a} & =\left(\mathfrak{x}_{a}+\mathfrak{y}_{a}\right)\frac{1}{r_{a}} \end{align} \quad(a)\\ \hline \begin{matrix}\begin{align}2\mathfrak{x}_{a} & =\left(r_{a}+\frac{1}{r_{a}}\right)x_{a}+\left(r_{a}-\frac{1}{r_{a}}\right)y_{a}\\ 2\mathfrak{y}_{a} & =\left(r_{a}-\frac{1}{r_{a}}\right)x_{a}+\left(r_{a}+\frac{1}{r_{a}}\right)y_{a} \end{align} \quad(b)\end{matrix}\\ \hline \left\{ \begin{matrix}r_{a}=\frac{\sqrt{s_{a}+1}}{\sqrt{s_{a}-1}}\\ s_{a}>1 \end{matrix}\right\}\Rightarrow\begin{align}\mathfrak{x}_{a} & =\frac{s_{a}x_{a}+y_{a}}{\sqrt{s_{a}-1}\sqrt{s_{a}+1}}\\ \mathfrak{y}_{a} & =\frac{x_{a}+s_{a}y_{a}}{\sqrt{s_{a}-1}\sqrt{s_{a}+1}} \end{align} \quad(c) \end{matrix}</math> <p style="background-color:Beige;border:1px solid black">Equation (a) is identical to Lorentz boost ({{equationNote|3d}}), while (c) is similar, though not identical, to Lorentz boost ({{equationNote|3b}}-C). The difference stems from his definition<br><math>\qquad\left\{ \begin{matrix}r_{a}=\frac{\sqrt{s_{a}+1}}{\sqrt{s_{a}-1}}\\ s_{a}>1 \end{matrix}\right\}</math><br>whereas in accordance to expression <math>\sqrt{\tfrac{1+v}{1-v}}</math> with <math>v<1</math> in ({{equationNote|3d}}) he should have stated <br><math>\qquad\left\{ \begin{matrix}r_{a}=\frac{\sqrt{1+s_{a}}}{\sqrt{1-s_{a}}}\\ s_{a}<1 \end{matrix}\right\}</math>.<br>Using the latter choice, equations (c) would assume a form equivalent to ({{equationNote|3b}}):<br><math>\qquad\begin{align}\mathfrak{x}_{a} & =\frac{x_{a}+s_{a}y_{a}}{\sqrt{1-s_{a}}\sqrt{1+s_{a}}}\\ \mathfrak{y}_{a} & =\frac{s_{a}x_{a}+y_{a}}{\sqrt{1-s_{a}}\sqrt{1+s_{a}}}\end{align}</math></p> ==={{Anchor|Schur}} Schur (1885/86, 1900/02) – Beltrami coordinates=== [[w:Friedrich Schur]] (1885/86) discussed spaces of constant Riemann curvature, and by following [[#Beltrami|Beltrami (1868)]] he used the transformation<ref group=M>Schur (1885/86), p. 167</ref> :<math>x_{1}=R^{2}\frac{y_{1}+a_{1}}{R^{2}+a_{1}y_{1}},\ x_{2}=R\sqrt{R^{2}-a_{1}^{2}}\frac{y_{2}}{R^{2}+a_{1}y_{1}},\dots,\ x_{n}=R\sqrt{R^{2}-a_{1}^{2}}\frac{y_{n}}{R^{2}+a_{1}y_{1}}</math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Lorentz transformation ({{equationNote|3e}}) and therefore also equivalent to the relativistic velocity addition [[../Lorentz transformation (velocity)#math_4d|E:'''(4d)''']] in arbitrary dimensions by setting ''R=c'' as the speed of light and ''a₁=v'' as relative velocity.</p> In (1900/02) he derived basic formulas of non-Eucliden geometry, including the case of translation for which he obtained the transformation similar to his previous one:<ref group=M>Schur (1900/02), p. 290; (1909), p. 83</ref> :<math>x'=\frac{x-a}{1-\mathfrak{k}ax},\quad y'=\frac{y\sqrt{1-\mathfrak{k}a^{2}}}{1-\mathfrak{k}ax}</math> where <math>\mathfrak{k}</math> can have values >0, <0 or ∞. <p style="background-color:Beige;border:1px solid black">This is equivalent to Lorentz transformation ({{equationNote|3e}}) and therefore also equivalent to the relativistic velocity addition [[../Lorentz transformation (velocity)#math_4d|E:'''(4d)''']] by setting ''a=v'' and <math>\mathfrak{k}=\tfrac{1}{c^{2}}</math>.</p> He also defined the triangle<ref group=M>Schur (1900/02), p. 291; (1909), p. 83</ref> :<math>\frac{1}{\sqrt{1-\mathfrak{k}c^{2}}}=\frac{1}{\sqrt{1-\mathfrak{k}a^{2}}}\cdot\frac{1}{\sqrt{1-\mathfrak{k}b^{2}}}-\frac{a}{\sqrt{1-\mathfrak{k}a^{2}}}\cdot\frac{b}{\sqrt{1-\mathfrak{k}b^{2}}}\cos\gamma</math> <p style="background-color:Beige;border:1px solid black">This is equivalent to the hyperbolic law of cosines and the relativistic velocity addition ({{equationNote|3f}}, b) or [[../Lorentz transformation (velocity)#math_4e|E:'''(4e)''']] by setting <math>[\mathfrak{k},\ c,\ a,\ b]=\left[\tfrac{1}{c^{2}},\ \sqrt{u_{x}^{\prime2}+u_{y}^{\prime2}},\ v,\ \sqrt{u_{x}^{2}+u_{y}^{2}}\right]</math>.</p> ==={{anchor|Lindemann}} Lindemann (1890–91) – Weierstrass coordinates and Cayley absolute=== [[w:Ferdinand von Lindemann]] discussed hyperbolic geometry in terms of the [[w:Cayley–Klein metric]] in his (1890/91) edition of the lectures on geometry of [[w:Alfred Clebsch]]. Citing [[../Lorentz transformation (general)#Killing|E:Killing (1885)]] and [[../Lorentz transformation (general)#Poincare|Poincaré (1887)]] in relation to the hyperboloid model in terms of Weierstrass coordinates for the hyperbolic plane and space, he set<ref group=M>Lindemann & Clebsch (1890/91), pp. 477–478, 524</ref> :<math>\begin{matrix}\Omega_{xx}=x_{1}^{2}+x_{2}^{2}-4k^{2}x_{3}^{2}=-4k^{2}\ \text{and}\ ds^{2}=dx_{1}^{2}+dx_{2}^{2}-4k^{2}dx_{3}^{2}\\ \Omega_{xx}=x_{1}^{2}+x_{2}^{2}+x_{3}^{2}-4k^{2}x_{4}^{2}=-4k^{2}\ \text{and}\ ds^{2}=dx_{1}^{2}+dx_{2}^{2}+dx_{3}^{2}-4k^{2}dx_{4}^{2} \end{matrix}</math> and used the following transformation<ref group=M>Lindemann & Clebsch (1890/91), pp. 361–362</ref> :<math>\begin{matrix}X_{1}X_{4}+X_{2}X_{3}=0\\ X_{1}X_{4}+X_{2}X_{3}=\Xi_{1}\Xi_{4}+\Xi_{2}\Xi_{3}\\ \hline \begin{align}X_{1} & =\left(\lambda+\lambda_{1}\right)U_{4} & \Xi_{1} & =\left(\lambda-\lambda_{1}\right)U_{4} & X_{1} & =\frac{\lambda+\lambda_{1}}{\lambda-\lambda_{1}}\Xi_{1}\\ X_{2} & =\left(\lambda+\lambda_{3}\right)U_{4} & \Xi_{2} & =\left(\lambda-\lambda_{3}\right)U_{4} & X_{2} & =\frac{\lambda+\lambda_{3}}{\lambda-\lambda_{3}}\Xi_{2}\\ X_{3} & =\left(\lambda-\lambda_{3}\right)U_{2} & \Xi_{3} & =\left(\lambda+\lambda_{3}\right)U_{2} & X_{3} & =\frac{\lambda-\lambda_{3}}{\lambda+\lambda_{3}}\Xi_{3}\\ X_{4} & =\left(\lambda-\lambda_{1}\right)U_{1} & \Xi_{4} & =\left(\lambda+\lambda_{1}\right)U_{1} & X_{4} & =\frac{\lambda-\lambda_{1}}{\lambda+\lambda_{1}}\Xi_{4} \end{align} \end{matrix}</math> into which he put<ref group=M name=linde>Lindemann & Clebsch (1890/91), p. 496</ref> :<math>\begin{align}X_{1} & =x_{1}+2kx_{4}, & X_{2} & =x_{2}+ix_{3}, & \lambda+\lambda_{1} & =\left(\lambda-\lambda_{1}\right)e^{a},\\ X_{4} & =x_{1}-2kx_{4}, & X_{3} & =x_{2}-ix_{3}, & \lambda+\lambda_{3} & =\left(\lambda-\lambda_{3}\right)e^{\alpha i}, \end{align} </math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Lorentz boost ({{equationNote|3d}}) with <math>e^{\alpha i}=1</math> and ''2k=1'' .</p> From that, he obtained the following Cayley absolute and the corresponding most general motion in hyperbolic space comprising ordinary rotations (''a''=0) or translations (α=0):<ref group=M name=linde /> :<math>\begin{matrix}x_{1}^{2}+x_{2}^{2}+x_{3}^{2}-4k^{2}x_{4}^{2}=0\\ \hline \begin{align}x_{2} & =\xi_{2}\cos\alpha+\xi_{3}\sin\alpha, & x_{1} & =\xi_{1}\cos\frac{a}{i}+2ki\xi_{4}\sin\frac{a}{i},\\ x_{3} & =-\xi_{2}\sin\alpha+\xi_{3}\cos\alpha, & 2kx_{4} & =i\xi_{1}\sin\frac{a}{i}+2k\xi_{4}\cos\frac{a}{i}. \end{align} \end{matrix}</math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Lorentz boost ({{equationNote|3b}}) with α=0 and ''2k=1''.</p> ==={{anchor|Gerard}} Gérard (1892) – Weierstrass coordinates=== [[w:Louis Gérard]] (1892) – in a thesis examined by Poincaré – discussed Weierstrass coordinates (without using that name) in the plane and gave the case of translation as follows:<ref group=M name=gerard>Gérard (1892), pp. 40–41</ref> :<math>\begin{align}X & =Z_{0}X'+X_{0}Z'\\ Y & =Y'\\ Z & =X_{0}X'+Z_{0}Z' \end{align} \ \text{with}\ \begin{align}X_{0} & =\operatorname{sh}OO'\\ Z_{0} & =\operatorname{ch}OO' \end{align} </math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Lorentz boost ({{equationNote|3b}}).</p> ==={{anchor|Killing2}} Killing (1893,97) – Weierstrass coordinates=== [[w:Wilhelm Killing]] (1878–1880) gave case of translation in the form<ref group=M name=killtra>Killing (1893), p. 331</ref> :<math>y_{0}=x_{0}\operatorname{Ch}a+x_{1}\operatorname{Sh}a,\quad y_{1}=x_{0}\operatorname{Sh}a+x_{1}\operatorname{Ch}a,\quad y_{2}=x_{2}</math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Lorentz boost ({{equationNote|3b}}).</p> In 1898, Killing wrote that relation in a form similar to [[#Escherich|Escherich (1874)]], and derived the corresponding Lorentz transformation for the two cases were ''v'' is unchanged or ''u'' is unchanged:<ref group=M name=kill98>Killing (1898), p. 133</ref> :<math>\begin{matrix}\xi'=\frac{\xi\operatorname{Ch}\frac{\mu}{l}+l\operatorname{Sh}\frac{\mu}{l}}{\frac{\xi}{l}\operatorname{Sh}\frac{\mu}{l}+\operatorname{Ch}\frac{\mu}{l}},\ \eta'=\frac{\eta}{\frac{\xi}{l}\operatorname{Sh}\frac{\mu}{l}+\operatorname{Ch}\frac{\mu}{l}}\\ \hline \frac{u}{p}=\xi,\ \frac{v}{p}=\eta\\ \hline p'=p\operatorname{Ch}\frac{\mu}{l}+\frac{u}{l}\operatorname{Sh}\frac{\mu}{l},\quad u'=pl\operatorname{Sh}\frac{\mu}{l}+u\operatorname{Ch}\frac{\mu}{l},\quad v'=v\\ \text{or}\\ p'=p\operatorname{Ch}\frac{\nu}{l}+\frac{v}{l}\operatorname{Sh}\frac{\nu}{l},\quad u'=u,\quad v'=pl\operatorname{Sh}\frac{\nu}{l}+v\operatorname{Ch}\frac{\nu}{l} \end{matrix}</math> <p style="background-color:Beige;border:1px solid black">The upper transformation system is equivalent to Lorentz transformation ({{equationNote|3e}}) and the velocity addition [[../Lorentz transformation (velocity)#math_4d|E:'''(4d)''']] with ''l=c'' and <math>\mu=c\operatorname{atanh}\tfrac{v}{c}</math>, the system below is equivalent to Lorentz boost ({{equationNote|3b}}).</p> ==={{anchor|Whitehead}} Whitehead (1897/98) – Universal algebra=== [[w:Alfred North Whitehead]] (1898) discussed the kinematics of hyperbolic space as part of his study of [[w:universal algebra]], and obtained the following transformation:<ref group=M name=white>Whitehead (1898), pp. 459–460</ref> :<math>\begin{align}x' & =\left(\eta\cosh\frac{\delta}{\gamma}+\eta_{1}\sinh\frac{\delta}{\gamma}\right)e+\left(\eta\sinh\frac{\delta}{\gamma}+\eta_{1}\cosh\frac{\delta}{\gamma}\right)e_{1}\\ & \qquad+\left(\eta_{2}\cos\alpha+\eta_{3}\sin\alpha\right)e_{2}+\left(\eta_{3}\cos\alpha-\eta_{2}\sin\alpha\right)e_{3} \end{align} </math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Lorentz boost ({{equationNote|3b}}) with α=0.</p> ==={{anchor|Elliott}} Elliott (1903) – Invariant theory === [[w:Edwin Bailey Elliott]] (1903) discussed a special cyclical subgroup of ternary linear transformations for which the (unit) determinant of transformation is resoluble into three ordinary algebraical factors, which he pointed out is in direct analogy to a subgroup formed by the following transformations:<ref group=M>Elliott (1903), p. 109</ref> :<math>\begin{matrix}x=X\cosh\phi+Y\sinh\phi,\quad y=X\sinh\phi+Y\cosh\phi\\ \hline X+Y=e^{-\phi}(x+y),\quad X-Y=e^{\phi}(x-y) \end{matrix}</math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Lorentz boost ({{equationNote|3b}}) and ({{equationNote|3d}}). The mentioned subgroup corresponds to the one-parameter subgroup generated by Lorentz boosts.</p> ==={{anchor|Woods2}} Woods (1903) – Weierstrass coordinates === [[w:Frederick S. Woods]] (1903, published 1905) gave the case of translation in hyperbolic space:<ref group=M>Woods (1903/05), p. 55</ref> :<math>x_{1}^{\prime}=x_{1}\cos kl+x_{0}\frac{\sin kl}{k},\quad x_{2}^{\prime}=x_{2},\quad x_{2}^{\prime}=x_{3},\quad x_{0}^{\prime}=-x_{1}k\sin kl+x_{0}\cos kl</math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Lorentz boost ({{equationNote|3b}}) with ''k''²=-1.</p> and the loxodromic substitution for hyperbolic space:<ref group=M>Woods (1903/05), p. 72</ref> :<math>\begin{matrix}\begin{align}x_{1}^{\prime} & =x_{1}\cosh\alpha-x_{0}\sinh\alpha\\ x_{2}^{\prime} & =x_{2}\cos\beta-x_{3}\sin\beta\\ x_{3}^{\prime} & =x_{2}\sin\beta+x_{3}\cos\beta\\ x_{0}^{\prime} & =-x_{1}\sinh\alpha+x_{0}\cosh\alpha \end{align} \end{matrix}</math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Lorentz boost ({{equationNote|3b}}) with β=0.</p> ==={{anchor|Liebmann}} Liebmann (1904–05) – Weierstrass coordinates=== [[w:Heinrich Liebmann]] (1904/05) – citing Killing (1885), Gérard (1892), Hausdorff (1899) – gave the case of translation in the hyperbolic plane:<ref group=M name=lieb>Liebmann (1904/05), p. 174</ref> :<math>x_{1}^{\prime}=x'\operatorname{ch}a+p'\operatorname{sh}a,\quad y_{1}^{\prime}=y',\quad p_{1}^{\prime}=x'\operatorname{sh}a+p'\operatorname{ch}a</math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Lorentz boost ({{equationNote|3b}}).</p> ==={{anchor|Frank}} Frank (1909) – Special relativity=== In special relativity, hyperbolic functions were used by [[w:Philipp Frank]] (1909), who derived the Lorentz transformation using ''ψ'' as rapidity:<ref group=R>Frank (1909), pp. 423-425</ref> :<math>\begin{matrix}x'=x\varphi(a)\,{\rm ch}\,\psi+t\varphi(a)\,{\rm sh}\,\psi\\ t'=-x\varphi(a)\,{\rm sh}\,\psi+t\varphi(a)\,{\rm ch}\,\psi\\ \hline {\rm th}\,\psi=-a,\ {\rm sh}\,\psi=\frac{a}{\sqrt{1-a^{2}}},\ {\rm ch}\,\psi=\frac{1}{\sqrt{1-a^{2}}},\ \varphi(a)=1\\ \hline x'=\frac{x-at}{\sqrt{1-a^{2}}},\ y'=y,\ z'=z,\ t'=\frac{-ax+t}{\sqrt{1-a^{2}}} \end{matrix}</math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Lorentz boost ({{equationNote|3b}}).</p> === {{anchor|Herglotz1}} Herglotz (1909/10) – Special relativity=== In special relativity, [[w:Gustav Herglotz]] (1909/10) classified the one-parameter Lorentz transformations as loxodromic, hyperbolic, parabolic and elliptic, with the hyperbolic case being:<ref group=R>Herglotz (1909/10), pp. 404-408</ref> :<math>\begin{matrix}Z=Z'e^{\vartheta}\\ \begin{aligned}x & =x', & t-z & =(t'-z')e^{\vartheta}\\ y & =y', & t+z & =(t'+z')e^{-\vartheta} \end{aligned} \end{matrix}</math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Lorentz boost ({{equationNote|3d}}).</p> ==={{anchor|Varicak}} Varićak (1910) – Special relativity=== In special relativity, hyperbolic functions were used by [[w:Vladimir Varićak]] in several papers starting from 1910, who represented the equations of special relativity on the basis of [[w:hyperbolic geometry]] in terms of Weierstrass coordinates. For instance, by setting ''l=ct'' and ''v/c=tanh(u)'' with ''u'' as rapidity he wrote the Lorentz transformation in agreement with ({{equationNote|4b}}):<ref group=R name=var1>Varićak (1910), p. 93</ref> :<math>\begin{align}l' & =-x\operatorname{sh}u+l\operatorname{ch}u,\\ x' & =x\operatorname{ch}u-l\operatorname{sh}u,\\ y' & =y,\quad z'=z,\\ \operatorname{ch}u & =\frac{1}{\sqrt{1-\left(\frac{v}{c}\right)^{2}}} \end{align} </math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Lorentz boost ({{equationNote|3b}}).</p> He showed the relation of rapidity to the [[w:Gudermannian function]] and the [[w:angle of parallelism]]:<ref group=R name=var1 /> :<math>\frac{v}{c}=\operatorname{th}u=\operatorname{tg}\psi=\sin\operatorname{gd}(u)=\cos\Pi(u)</math> He also related the velocity addition to the [[w:hyperbolic law of cosines]]:<ref group=R>Varićak (1910), p. 94</ref> :<math>\begin{matrix}\operatorname{ch}{u}=\operatorname{ch}{u_{1}}\operatorname ch{u_{2}}+\operatorname{sh}{u_{1}}\operatorname{sh}{u_{2}}\cos\alpha\\ \operatorname{ch}{u_{i}}=\frac{1}{\sqrt{1-\left(\frac{v_{i}}{c}\right)^{2}}},\ \operatorname{sh}{u_{i}}=\frac{v_{i}}{\sqrt{1-\left(\frac{v_{i}}{c}\right)^{2}}}\\ v=\sqrt{v_{1}^{2}+v_{2}^{2}-\left(\frac{v_{1}v_{2}}{c}\right)^{2}}\ \left(a=\frac{\pi}{2}\right) \end{matrix}</math> ==References== ===Historical mathematical sources=== {{reflist|3|group=M}} *{{#section:History of Topics in Special Relativity/mathsource|bel68sag}} *{{#section:History of Topics in Special Relativity/mathsource|bel68fond}} *{{#section:History of Topics in Special Relativity/mathsource|cox81hom}} *{{#section:History of Topics in Special Relativity/mathsource|cox82hom}} *{{#section:History of Topics in Special Relativity/mathsource|eli03}} *{{#section:History of Topics in Special Relativity/mathsource|esch74}} *{{#section:History of Topics in Special Relativity/mathsource|eul35}} *{{#section:History of Topics in Special Relativity/mathsource|eul48a}} *{{#section:History of Topics in Special Relativity/mathsource|ger92}} *{{#section:History of Topics in Special Relativity/mathsource|glai78}} *{{#section:History of Topics in Special Relativity/mathsource|gud30}} *{{#section:History of Topics in Special Relativity/mathsource|guen80}} *{{#section:History of Topics in Special Relativity/mathsource|kep09}} *{{#section:History of Topics in Special Relativity/mathsource|kil93}} *{{#section:History of Topics in Special Relativity/mathsource|kil97}} *{{#section:History of Topics in Special Relativity/mathsource|lag70}} *{{#section:History of Topics in Special Relativity/mathsource|lais74b}} *{{#section:History of Topics in Special Relativity/mathsource|lam67}} *{{#section:History of Topics in Special Relativity/mathsource|lam70}} *{{#section:History of Topics in Special Relativity/mathsource|lieb04}} *{{#section:History of Topics in Special Relativity/mathsource|lind90}} *{{#section:History of Topics in Special Relativity/mathsource|lip86}} *{{#section:History of Topics in Special Relativity/mathsource|ric57}} *{{#section:History of Topics in Special Relativity/mathsource|schu85}} *{{#section:History of Topics in Special Relativity/mathsource|schu00}} *{{#section:History of Topics in Special Relativity/mathsource|schu09}} *{{#section:History of Topics in Special Relativity/mathsource|tau26}} *{{#section:History of Topics in Special Relativity/mathsource|whit98}} *{{#section:History of Topics in Special Relativity/mathsource|woo01}} *{{#section:History of Topics in Special Relativity/mathsource|woo03}} ===Historical relativity sources=== {{reflist|3|group=R}} *{{#section:History of Topics in Special Relativity/relsource|frank09a}} *{{#section:History of Topics in Special Relativity/relsource|herg10}} *{{#section:History of Topics in Special Relativity/relsource|var10}} *{{#section:History of Topics in Special Relativity/relsource|var12}} ===Secondary sources=== {{reflist|3}} {{#section:History of Topics in Special Relativity/secsource|L3}} [[Category:Special Relativity]] [[Category:History of Physics]] 0xt5lyjem9s1peup2x7wvzivuoecbm8 0 267598 2414075 2413928 2022-08-13T11:24:28Z D.H 52339 /* Lorentz transformation via sphere transformation */ wikitext text/x-wiki {{../Lorentz transformation (header)}} ==Lorentz transformation via sphere transformation== If one only requires the invariance of the light cone represented by the differential equation <math>-dx_{0}^{2}+\dots+dx_{n}^{2}=0</math>, which is the same as asking for the most general transformation that changes spheres into spheres, the Lorentz group can be extended by adding dilations represented by the factor λ. The result is the group Con(1,p) of spacetime [[w:conformal transformation]]s in terms of [[w:special conformal transformation]]s and inversions producing the relation :<math>-dx_{0}^{2}+\dots+dx_{n}^{2}=\lambda\left(-dx_{0}^{\prime2}+\dots+dx_{n}^{\prime2}\right)</math>. One can switch between two representations of this group by using an imaginary sphere radius coordinate ''x₀=iR'' with the interval <math>dx_{0}^{2}+\dots+dx_{n}^{2}</math> related to conformal transformations, or by using a real radius coordinate ''x₀=R'' with the interval <math>-dx_{0}^{2}+\dots+dx_{n}^{2}</math> related to [[#Lie|Lie's (1871)]] sphere transformation (or [[w:spherical wave transformation]]s) in terms of [[w:contact transformation]]s preserving circles and spheres. It was shown by [[#Bateman|Bateman & Cunningham (1909–1910)]], that the group Con(1,3) is the most general one leaving invariant the equations of Maxwell's electrodynamics. It turns out that Con(1,3) is isomorphic to the [[w:special orthogonal group]] SO(2,4), and contains the Lorentz group SO(1,3) as a subgroup by setting λ=1. More generally, Con(q,p) is isomorphic to SO(q+1,p+1) and contains SO(q,p) as subgroup.<ref>Schottenloher (2008), section 2.2</ref> This implies that Con(0,p) is isomorphic to the Lorentz group of arbitrary dimensions SO(1,p+1). Consequently, the conformal group in the plane Con(0,2) – known as the group of [[w:Möbius transformation]]s – is isomorphic to the Lorentz group SO(1,3).<ref>Kastrup (2008), section 2.4.1</ref><ref>Schottenloher (2008), section 2.3</ref> This can be seen using tetracyclical coordinates satisfying the form <math>-x_{0}^{2}+x_{1}^{2}+x_{2}^{2}+x_{3}^{2}=0</math>, which were discussed by [[#Klein3|Pockels (1891), Klein (1893), Bôcher (1894)]]. The relation between Con(1,3) and the Lorentz group was noted by [[#Bateman|Bateman & Cunningham (1909–1910)]] and others. (For a different take on the Möbius group, see also [[../Lorentz transformation (Möbius)|E:Lorentz transformation via Cayley–Klein parameters, Möbius and spin transformations]]). A subgroup of Lie's group of sphere transformations is the [[w:Spherical wave transformation#Transformation by reciprocal directions|Laguerre group]] (or ''group of transformations by reciprocal directions'') dealing with oriented spheres, planes and lines, which was already implicit in the work of [[#Ribaucour|Ribaucour (1870)]], [[#Lie|Lie (1871)]], [[#Darboux|Darboux (1873)]]. It's generated by the Laguerre inversion introduced by [[#Laguerre|Laguerre (1882)]] and discussed by [[#Darboux|Darboux (1887)]] and [[#Smith|Smith (1900)]] leaving invariant <math>X^{2}+Y^{2}+Z^{2}-R^{2}</math> with ''R'' as radius, thus the Laguerre group is isomorphic to the Lorentz group. A similar concept was studied by [[#Scheffers|Scheffers (1899)]] in terms of contact transformations. [[#Stephanos|Stephanos (1883)]] argued that Lie's geometry of oriented spheres in terms of contact transformations, as well as the special case of the transformations of oriented planes into each other (such as by Laguerre), provides a geometrical interpretation of Hamilton's [[w:biquaternion]]s. The [[w:group isomorphism]] between the Laguerre group and Lorentz group was pointed out by [[#Bateman|Bateman (1910), Cartan (1912, 1915/55), Poincaré (1912/21)]] and others.<ref>Coolidge (1916), p. 370</ref><ref name="ReferenceA">Cartan & Fano (1915/55), sections 14–15</ref> The Laguerre inversion was written in the following ways: {{NumBlk|:|<math>\begin{matrix}-R^{2}+X^{2}=-R^{\prime2}+X^{\prime2}\\ \hline \begin{align}R' & =-R\frac{1+a^{2}}{1-a^{2}}+X\frac{2a}{1-a^{2}}\\ X' & =-R\frac{2a}{1-a^{2}}+X\frac{1+a^{2}}{1-a^{2}} \end{align} \end{matrix}</math>|{{equationRef|1}}}} or {{NumBlk|:|<math>\begin{matrix}-R^{2}+X^{2}=-R^{\prime2}+X^{\prime2}\\ \hline \begin{align}R' & =-\frac{1}{2}\left(k+\frac{1}{k}\right)R+\frac{1}{2}\left(k-\frac{1}{k}\right)X\\ X' & =-\frac{1}{2}\left(k-\frac{1}{k}\right)R+\frac{1}{2}\left(k+\frac{1}{k}\right)X \end{align} \end{matrix}</math>|{{equationRef|2}}}} A special case of Laguerre inversions (1, 2) with <math>a=k=\sqrt{-1}</math> was already given by [[#Bonnet|Bonnet (1856)]]. Formula (1) was given by [[#Laguerre|Laguerre (1882)]] and [[#Darboux|Darboux (1887)]], formula (2) by [[#Smith|Smith (1900)]]. Laguerre transformations in trigonometric form were given by [[#Scheffers|Scheffers (1899)]]. Formulas (1, 2) are antichronous Lorentz transformations, which become orthochronous by changing the sign of <math>R'</math>. Furthermore, setting <math>v=\tfrac{2a}{1+a^{2}}=\tfrac{k^{2}-1}{k^{2}+1}</math> together with <math>\cos\alpha'=\tfrac{X'}{-R'}</math> and <math>\cos\alpha=\tfrac{X}{R}</math> gives: {{NumBlk|:|<math>\cos\alpha'=\frac{\cos\alpha-v}{1-v\cos\alpha}\quad\text{or}\quad\tan\frac{\alpha'}{2}=\sqrt{\frac{1+v}{1-v}}\tan\frac{\alpha}{2}</math>|{{equationRef|3}}}} Formula (3) was already used by [[#Darboux|Darboux (1873)]] as a sphere transformation, and in 1881 he showed that it can also be used to perform Laguerre transformations of planes. In special relativity, it turns out that formula (3) describes the aberration of light, see [[../Lorentz transformation (velocity)#Velocity addition and aberration|E:velocity addition and aberration]]. ==Historical notation== ==={{anchor|Bonnet}} Bonnet (1856) === [[w:Pierre Ossian Bonnet]] (1856) defined a reciprocal transformation preserving lines of curvatures. He noted that his transformation implies the following relation between curvature radii <math>\rho,\rho_{1}</math> and ordinates <math>\zeta,\zeta_{1}</math> of the respective curvature centers:<ref group=M>Bonnet (1856), p. 487</ref> :<math>\rho_{1}=i\zeta,\quad\rho=-i\zeta_{1}</math> where <math>i=\sqrt{-1}</math> <p style="background-color:Beige;border:1px solid black">Bonnet's transformation produces <math>\rho^{2}-\zeta^{2}=\rho_{1}^{2}-\zeta_{1}^{2}</math> and represents a special case of Laguerre inversion (or Lorentz transformation) ({{equationNote|1}}, {{equationNote|2}}) with <math>a=k=\sqrt{-1}</math>. [[#Lie|Lie (1871)]], [[#Darboux|Darboux (1887)]] and [[#Smith|Smith (1900)]] all noticed that Bonnet's transformation is a special case of Lie's and Laguerre's transformations.</p> ==={{anchor|Ribaucour}} Ribaucour (1870) === [[w:Albert Ribaucour]] (1870),<ref group=M>Ribaucour (1870). pp. 330-333</ref> defined what was later called “Ribaucour transformations” preserving lines of curvature: :p. 330: If circles are normal to three surfaces, they are normal to a family of surfaces belonging to a triply orthogonal system. This results in a class of orthogonal triple systems which I will propose to call cyclic systems, intimately linked to the deformation of surfaces. Given a surface (A), we can propose to seek all the cyclic systems which derive from it; the <math>ds^{2}</math> of this surface being put in the form <math>ds^{2}=\lambda^{2}.dx\ dy</math> [...] :p. 332: If spheres have their contact chords normal to surfaces, the circles passing through the centers of these spheres and their points of contact with their enveloping surfaces are normal to an infinity of surfaces forming part of a cyclic system. [...] If surfaces are part of an orthogonal system, the osculating circles of their orthogonal trajectories corresponding to all the points of one of these surfaces are normal to a family of surfaces belonging to a cyclic system. [...] I will point out the simple case where (A) is a plane, a case which leads to a general transformation of the surfaces with correspondence of the lines of curvature [...]. <p style="background-color:Beige;border:1px solid black">Referring to p. 332 of Ribaucour's paper, [[#Darboux|Darboux (1887)]] and [[#Bateman|Bateman (1910)]] argued that Ribaucour anticipated both [[#Lie|Lie (1871)]] and [[#Laguerre|Laguerre (1880)]] in formulating the “transformation by reciprocal directions”, which in Darboux's representation led to algebraic expressions identical to Laguerre inversion (or Lorentz transformation) ({{equationNote|1}}) and ({{equationNote|3}}).</p> ==={{anchor|Lie}} Lie (1871)=== In several papers between 1847 and 1850 it was shown by [[w:Joseph Liouville]]<ref group=M>Liouville (1847)</ref> that the relation ''λ(δx²+δy²+δz²)'' is invariant under the group of [[w:conformal transformation]]s generated by [[w:Spherical wave transformation#Transformation by reciprocal radii|w:inversions]] transforming spheres into spheres, which can be related [[w:special conformal transformation]]s or [[w:Möbius transformation]]s. (The conformal nature of the linear fractional transformation <math>\tfrac{a+bz}{c+dz}</math> of a complex variable <math>z</math> was already discussed by Euler (1777)).<ref group=M>Euler (1777), p. 140</ref><ref name=kastrup>Kastrup (2008), section 2.1</ref> Liouville's theorem was extended to all dimensions by [[w:Sophus Lie]] (1871a).<ref group=M name=lie1>Lie (1871), pp. 199–209</ref><ref>Kastrup (2008), section 2.3</ref> In addition, Lie described a manifold whose elements can be represented by spheres, where the last coordinate ''y_n+1'' can be related to an imaginary radius by ''iy_n+1'':<ref group=M name=lie1 /> :<math>\begin{matrix}\sum_{i=1}^{i=n} (x_i-y_i)^2+y_{n+1}^2=0 \\ \downarrow\\ \sum_{i=1}^{i=n+1} (y_i^{\prime}-y_i^{\prime\prime})^2=0 \end{matrix}</math> If the second equation is satisfied, two spheres ''y′'' and ''y″'' are in contact. Lie then defined the correspondence between [[w:Contact geometry|w:contact transformations]] in ''R_n'' and conformal point transformations in ''R_n+1'': The sphere of space ''R_n'' consists of ''n+1'' parameter (coordinates plus imaginary radius), so if this sphere is taken as the element of space ''R_n'', it follows that ''R_n'' now corresponds to ''R_n+1''. Therefore, any transformation (to which he counted [[../Lorentz transformation (imaginary)#Lorentz transformation via orthogonal transformation|E:orthogonal transformations]] and inversions) leaving invariant the condition of contact between spheres in ''R_n'', corresponds to the conformal transformation of points in ''R_n+1''. He pointed out that conformal point transformations consist of motions (such as [[w:rigid transformation]]s and orthogonal transformations), similarity transformations, and inversions.<ref group=M>Lie (1871/72), first footnote on p. 186</ref> <p style="background-color:Beige;border:1px solid black">As shown by [[#Bateman|Bateman and Cunningham (1909)]], the spacetime conformal group Con(1,3) of "[[w:spherical wave transformation]]s" corresponds to the transformations of Lie's sphere geometry in which the radius indicates the fourth coordinate, while the Lorentz group SO(1,3) is a subgroup of Con(1,3). It's also known that the Möbius group and Laguerre group, which are both isomorphic to the Lorentz group, are subgroups of Lie's sphere transformations group.</p> In the same paper, Lie also mentioned the “well known fact” that “parallel transformations” (dilatations having the property of transforming planes to parallel planes) preserve lines of curvature, and he alluded to [[#Bonnet|Bonnet's (1856)]] transformation as an example.<ref group=M>Lie (1871/72), p. 184</ref> Generally, all of the discussed transformations that preserve lines of curvature are either inversions or parallel transformations.<ref group=M>Lie (1871/72), p. 186</ref> In a footnote he specifically remarked that line transformations under which "(const=0)" remains unchanged, give all transformations of ''R'' by which surfaces of common spherical image pass into other such surfaces, and that the new spherical image emerges from the former by a conformal point transformation of the image-sphere, and that [[#Bonnet|Bonnet's (1856)]] transformation belongs here.<ref group=M>Lie (1871/72), second footnote on p. 186</ref> <p style="background-color:Beige;border:1px solid black">Lie himself (1884)<ref group=M>Lie (1884), footnote on p. 541</ref> pointed out that his remarks indicate the same transformation group treated in more recent works of [[#Laguerre|Laguerre (1880-82)]] and [[#Stephanos|Stephanos (1882)]]. Consequently, [[#Smith|Smith (1900)]] credits Lie as being the first one to allude to the existence of the (extended) Laguerre group, transforming spheres into spheres and planes into planes. On the other hand, [[#Darboux|Darboux (1887)]] pointed out that the transformation by reciprocal directions was already anticipated by [[#Ribaucour|Ribaucour (1870)]] even before Lie.</p> ==={{anchor|Klein3}} Klein, Pockels, Bôcher (1871-91)=== In relation to line geometry, [[w:Felix Klein]] (1871/72)<ref group=M>Klein (1871/72), p. 268</ref> used coordinates satisfying the condition <math>s_{1}^{2}+s_{2}^{2}+s_{2}^{2}+s_{2}^{2}+s_{5}^{2}=0</math>. They were introduced in 1868 (belatedly published in 1873) by [[w:Gaston Darboux]]<ref group=M>Darboux (1873), p. 137</ref> as a system of five coordinates in ''R₃'' (later called "pentaspherical" coordinates) in which the last coordinate is imaginary. [[w:Sophus Lie]] (1871)<ref group=M>Lie (1871), p. 208</ref> more generally used ''n+2'' coordinates in ''R_n'' (later called "polyspherical" coordinates) satisfying <math>\scriptstyle \sum_{i=1}^{i=n+2}x_{i}^{2}=0</math> in which the last coordinate is imaginary, as a means to discuss conformal transformations generated by inversions. These simultaneous publications can be explained by the fact that Darboux, Lie, and Klein corresponded with each other by letter. When the last coordinate is defined as real, the corresponding polyspherical coordinates satisfy the form of a sphere. Initiated by lectures of Klein between 1889–1890, his student [[w:Friedrich Carl Alwin Pockels]] (1891) used such real coordinates, emphasizing that all of these coordinate systems remain invariant under conformal transformations generated by inversions:<ref group=M>Pockels (1891), pp. 197–206</ref> :<math>x_1^2+x_2^2+\cdots+x_{n+1}^2-x_{n+2}^2=0 \text{ or } \sum_1^{n+1} x_h^2-x_{n+2}^2=0</math> Special cases were described by Klein (1893):<ref group=M>Klein (1893c), pp. 200ff (pentaspherical), pp. 373ff (tetracyclical)</ref> :<math>y_1^2+y_2^2+y_3^2+y_4^2-y_5^2=0</math> (pentaspherical). :<math>x_1^2+x_2^2+x_3^2-x_4^2=0</math> (tetracyclical). Both systems were also described by [[w:Maxime Bôcher]] (1894) in an expanded version of a thesis supervised by Klein.<ref group=M>Bôcher (1894), pp. 30–34, 40–43</ref> <p style="background-color:Beige;border:1px solid black">Polyspherical coordinates indicate that the conformal group {{nowrap|Con(0,p)}} is isomorphic to the Lorentz group SO(1,p+1).<ref>Kastrup (2008), p. 22</ref> For instance, Con(0,2) – known as Möbius group – is related to tetracyclical coordinates satisfying <math>x_{1}^{2}+x_{2}^{2}+x_{3}^{2}-x_{4}^{2}=0</math>, which is nothing other than the Lorentz interval invariant under the Lorentz group SO(1,3).</p> ==={{anchor|Darboux}} Darboux (1873-87)=== In 1873, [[w:Gaston Darboux]] stated the following proposition:<ref group=M>Darboux (1873), pp. 254-255.</ref> :Given a surface <math>\left(\Sigma\right)</math>, we add a fixed sphere <math>\left({\rm S}\right)</math> to it, and we construct all spheres tangent to the surface and intersecting <math>\left({\rm S}\right)</math> at a constant angle <math>\alpha</math>. Through the intersection of each of these spheres and <math>\left({\rm S}\right)</math> new spheres pass intersecting <math>\left({\rm S}\right)</math> at a constant angle <math>\beta</math>. These new spheres envelop a surface <math>\left(\Sigma_{1}\right)</math>, corresponding point by point to <math>\left(\Sigma\right)</math> with conservation of lines of curvature. The corresponding points on the two surfaces are on circles normal both to the two surfaces and to the sphere <math>\left({\rm S}\right)</math>. which he generalized by making a second proposition:<ref group=M>Darboux (1873), footnote on p. 255.</ref> :Consider a surface <math>\left(\Sigma\right)</math>, envelope of a series of variable spheres <math>\left(\rm U\right)</math> intersecting under any angles the sphere <math>\left(\rm S\right)</math>. At each of the spheres <math>\left(\rm U\right)</math> intersecting <math>\left(\rm S\right)</math> at an angle I call <math>\varphi</math> we match a sphere <math>\left(\rm U_1\right)</math> passing through the intersection of <math>\left(\rm S\right)</math> and from <math>\left(\rm U \right)</math>, and intersecting <math>\left(\rm S\right)</math> at an angle <math>\varphi_1</math> determined by equation ::<math>\frac{\cos\varphi-\cos\varphi_{1}}{1-\cos\varphi\cos\varphi_{1}}=h</math> :Then the new spheres <math>\left(\rm U_1\right)</math> envelop a surface <math>\left(\Sigma_1\right)</math> which corresponds point by point at <math>\left(\Sigma\right)</math> with curvature lines preserved. If we subject the spheres <math>\left(\rm U\right)</math> tangent to <math>\left(\Sigma \right)</math> to cut <math>\left(\rm S\right)</math> under a constant angle, <math>\varphi</math> will be constant; it will be the same for <math>\varphi_1</math>, by virtue of the previous equation, and we find the theorem given above. » <p style="background-color:Beige;border:1px solid black">This is equivalent to Laguerre transformation (or Lorentz transformation) ({{equationNote|3}}) with <math>h=\beta</math>.</p> In 1881 he quoted his above propositions, gave priority to the first one to [[#Ribaucour|Ribaucour (1870)]], and then showed that Laguerre's transformation of reciprocal directions is included as well:<ref group=M>Darboux (1881), p. 286f.</ref> :This proposal gave a new means of realizing a mode of transformation of surfaces with preservation of the lines of curvature, to which [[#Ribaucour|Ribaucour]] had devoted a few lines in a Communication made to the Academy in 1870 ''sur la deformation des surfaces''. :[..] Suppose, in particular, that the sphere <math>\left(\rm S\right)</math> reduces to a plane <math>\left(\pi\right)</math>. Then to any plane <math>\left(\rm P\right)</math> will correspond a plane <math>\left(\rm P'\right)</math> passing through the intersection of <math>\left(\pi\right)</math> and <math>\left(\rm P\right)</math>, and the angles <math>\varphi,\varphi'</math> that the planes <math>\left(\rm P\right)</math>, <math>\left(\rm P'\right)</math> make with <math>\left(\pi\right)</math> will be linked by relation (1). It is not difficult to recognize, in this transformation from one plane to another, that which has recently been studied by [[#Laguerre|Laguerre]] under the name of ''transformation by reciprocal directions''. We see that it is included in the transformation of spheres which is defined by our second proposition. I have recalled these results only to arrive at the proposition which is the main object of this Communication. I will show, in accordance with a general theorem of [[#Lie|Lie]], that the transformation first proposed by [[#Ribaucour|Ribaucour]] boils down to dilatations (transition from a surface to the parallel surface) and to transformations by reciprocal vector rays. He went on to rewrite his 1873 equation as:<ref group=M>Darboux (1881), footnote on p. 287</ref> :<math>\mathrm{tang}\frac{\varphi}{2}=\mathrm{tang}\frac{\varphi_{1}}{2}\sqrt{\frac{1-h}{1 +h}}</math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Laguerre transformation (or Lorentz transformation) ({{equationNote|3}}) with <math>h=\beta</math>.</p> In 1887, Darboux gave a much more detailed account. For instance, he re-derived and extended the transformation of oriented half-lines given by [[#Laguerre|Laguerre (1882)]] using coordinates ''x,y,z,R'':<ref group=M>Darboux (1887), p. 254</ref> :<math>\begin{matrix}x^{\prime2}+y^{\prime2}+z^{\prime2}-R^{\prime2}=x^{2}+y^{2}+z^{2}-R^{2}\\ \hline \begin{align}x' & =x, & z' & =\frac{1+k^{2}}{1-k^{2}}z-\frac{2kR}{1-k^{2}},\\ y' & =y, & R' & =\frac{2kz}{1-k^{2}}-\frac{1+k^{2}}{1-k^{2}}R, \end{align} \end{matrix}</math> or <math>\begin{align}z'+R' & =\frac{1+k}{1-k}(z-R)\\ z'-R' & =\frac{1-k}{1+k}(z+R) \end{align}</math> He went on to derive expressions and theorems similar to those given by him in 1873, and added that [[#Bonnet|Bonnet's (1856)]] transformation is a special case.<ref group=M>Darboux (1887), p. 256</ref> <p style="background-color:Beige;border:1px solid black">This is equivalent to Laguerre inversion (or Lorentz transformation) ({{equationNote|1}}).</p> Regarding the history of such transformations (before Laguerre's research) he wrote:<ref group=M>Darboux (1887), footnote on p. 259</ref> :In the memoir already quoted, inserted in volume V of ''Mathematische Annalen'', [[#Lie|Lie]] has made known all the contact transformations which preserve the lines of curvature; he even pointed out (p. 186) the particular case of transformation by reciprocal directions; but this transformation had already been given in different works by [[#Ribaucour|Ribaucour]]. See, in particular, Ribaucour's note ''sur la deformation des surfaces (Comptes rendus, t. LXX, p. 332, 1870)''. In a different form, it was the subject of the author's studies published in Notes V and IX of ''Mémoire sur une classe remarquable de courbes et de surfaces algébriques'', 1873. ==={{anchor|Laguerre}} Laguerre (1880-82) === A systematic formulation of a geometry of orientation was given by [[w:Edmond Laguerre]] (1880), including geometric transformations of oriented planes into oriented planes and oriented spheres into oriented spheres, which he called "[[w:Spherical wave transformation#Transformation by reciprocal directions|w:transformation by reciprocal directions]]".<ref group=M>Laguerre (1880)</ref> Besides the focus on the transformation of planes, a distinguishing feature to previous authors was the employment of the concept of orientation (i.e. attributing a certain sign to lines and radii) which became an indispensable tool in Lie sphere geometry and Laguerre geometry. <p style="background-color:Beige;border:1px solid black">Laguerre's transformations form a group (Laguerre group) which is isomorphic to the Lorentz group, and forms a subgroup of [[#Lie|Lie's (1871)]] contact transformations of spheres.</p> In 1882 he developed the “transformation of oriented half-lines” which was later called "Laguerre inversion", using the following algebraic formulation (''R'' being the radius and ''D'' the distance of its center to the axis):<ref group=M>Laguerre (1882), pp. 550–551.</ref> :<math>\left.\begin{align}D' & =\frac{D\left(1+\alpha^{2}\right)-2\alpha R}{1-\alpha^{2}}\\ R' & =\frac{2\alpha D-R\left(1+\alpha^{2}\right)}{1-\alpha^{2}} \end{align} \right|\begin{align}D^{2}-D^{\prime2} & =R^{2}-R^{\prime2}\\ D-D' & =\alpha(R-R')\\ D+D' & =\frac{1}{\alpha}(R+R') \end{align} </math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Laguerre inversion (or Lorentz transformation) ({{equationNote|1}}). The Laguerre inversions are generators of the Laguerre group.</p> ==={{anchor|Stephanos}} Stephanos (1883)=== [[w:Cyparissos Stephanos]] (1883)<ref group=M>Stephanos (1883), p. 590ff</ref> showed that Hamilton's biquaternion ''a₀+a₁ι₁+a₂ι₂+a₃ι₃'' can be interpreted as an oriented sphere in terms of [[#Lie|Lie's sphere geometry (1871)]], having the vector ''a₁ι₁+a₂ι₂+a₃ι₃'' as its center and the scalar <math>a_{0}\sqrt{-1}</math> as its radius. Its norm <math>a_{1}^{2}+a_{2}^{2}+a_{3}^{2}+a_{4}^{2}</math> is thus equal to the power of a point of the corresponding sphere. In particular, the norm of two quaternions ''N(Q₁-Q₂)'' (the corresponding spheres are in contact with ''N(Q₁-Q₂)=0'') is equal to the tangential distance between two spheres. The general contact transformation between two spheres then can be given by a [[w:homography]] using 4 arbitrary quaternions ''A,B,C,D'' and two variable quaternions ''X,Y'':<ref group=M>Stephanos (1883), p. 592</ref><ref>Cartan & Study (1908), p. 460</ref><ref>Rothe (1916), p. 1399</ref> :<math>XAY+XB+CY+D=0</math> (or <math>X=-\frac{CY+D}{AY+B}</math>). Stephanos pointed out that the special case ''A=0'' denotes transformations of oriented planes (see [[#Laguerre|Laguerre (1882)]]). <p style="background-color:Beige;border:1px solid black">The Lorentz group {{nowrap|SO(1,3)}} is a subgroup of the conformal group {{nowrap|Con(1,3)}} in terms of [[#Lie|Lie's (1871)]] transformations of oriented spheres in which the radius indicates the fourth coordinate. The Lorentz group is isomorphic to the group of [[#Laguerre|Laguerre's (1880)]] transformation of oriented planes.</p> ==={{anchor|Scheffers}} Scheffers (1899)=== [[w:Georg Scheffers]] (1899) synthetically determined all ''finite'' [[w:contact transformation]]s preserving circles in the plane, consisting of dilatations, inversions, and the following one preserving circles and lines (compare with Laguerre inversion by [[#Laguerre|Laguerre (1882)]] and [[#Darboux|Darboux (1887)]]):<ref group=M>Scheffers (1899), p. 158</ref> :<math>\begin{matrix}\sigma^{\prime2}-\rho^{\prime2}=\sigma^{2}-\rho^{2}\\ \hline \rho'=\frac{\rho}{\cos\omega}+\sigma\tan\omega,\quad\sigma'=\rho\tan\omega+\frac{\sigma}{\cos\omega} \end{matrix}</math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Laguerre transformation (or Lorentz transformation) ({{equationNote|1}}) by the identity <math>\sin\omega=\beta=\frac{2a}{1+a^{2}}=\frac{k^{2}-1}{k^{2}+1}</math>.</p> ==={{anchor|Smith}} Smith (1900)=== [[w:Percey F. Smith]] (1900) followed [[#Laguerre|Laguerre (1882)]] and [[#Darboux|Darboux (1887)]] and defined the Laguerre inversion as follows:<ref group=M>Smith (1900), p. 159</ref> :<math>\begin{matrix}p^{\prime2}-p^{2}=R^{\prime2}-R^{2}\\ \hline \kappa=\frac{R'-R}{p'-p}\\ p'=\frac{\kappa^{2}+1}{\kappa^{2}-1}p-\frac{2\kappa}{\kappa^{2}-1}R,\quad R'=\frac{2\kappa}{\kappa^{2}-1}p-\frac{\kappa^{2}+1}{\kappa^{2}-1}R \end{matrix}</math> He added that [[#Bonnet|Bonnet's (1856)]] transformation is a special case with <math>\kappa^{2}=-1</math>, and he also gave credit to [[#Lie|Lie (1871)]] for defining the corresponding "group of the geometry of reciprocal directions". <p style="background-color:Beige;border:1px solid black">This is equivalent to Laguerre inversion (or Lorentz transformation) ({{equationNote|2}}).</p> ==={{anchor|Bateman}} Bateman and Cunningham (1909–1910)=== In line with [[#Lie|Lie's (1871)]] research on the relation between sphere transformations with an imaginary radius coordinate and 4D conformal transformations, it was pointed out by [[w:Harry Bateman]] and [[w:Ebenezer Cunningham]] (1909–1910), that by setting ''u=ict'' as the imaginary fourth coordinates one can produce spacetime conformal transformations. Not only the quadratic form <math>\lambda\left(dx^{2}+dy^{2}+dz^{2}+du^{2}\right)</math>, but also [[w:Maxwells equations]] are covariant with respect to these transformations, irrespective of the choice of λ. These variants of conformal or Lie sphere transformations were called [[w:spherical wave transformation]]s by Bateman.<ref group=R>Bateman (1909/10), pp. 223ff</ref><ref group=R>Cunningham (1909/10), pp. 77ff</ref> However, this covariance is restricted to certain areas such as electrodynamics, whereas the totality of natural laws in inertial frames is covariant under the [[w:Lorentz group]].<ref group=R>Klein (1910)</ref> In particular, by setting λ=1 the Lorentz group {{nowrap|SO(1,3)}} can be seen as a 10-parameter subgroup of the 15-parameter spacetime conformal group {{nowrap|Con(1,3)}}. Bateman (1910/12)<ref>Bateman (1910/12), pp. 358–359</ref> also alluded to the identity between the [[#Laguerre|Laguerre inversion]] and the Lorentz transformations. In general, the isomorphism between the Laguerre group and the Lorentz group was pointed out by [[w:Élie Cartan]] (1912, 1915/55),<ref name="ReferenceA"/><ref group=R>Cartan (1912), p. 23</ref> [[w:Henri Poincaré]] (1912/21)<ref group=R>Poincaré (1912/21), p. 145</ref> and others. ==References== ===Historical mathematical sources=== {{reflist|3|group=M}} *{{#section:History of Topics in Special Relativity/mathsource|boch94pot}} *{{#section:History of Topics in Special Relativity/mathsource|bon56}} *{{#section:History of Topics in Special Relativity/mathsource|dar73}} *{{#section:History of Topics in Special Relativity/mathsource|dar81cou}} *{{#section:History of Topics in Special Relativity/mathsource|dar87cou}} *{{#section:History of Topics in Special Relativity/mathsource|eul77}} *{{#section:History of Topics in Special Relativity/mathsource|klei72a}} *{{#section:History of Topics in Special Relativity/mathsource|klei93c}} *{{#section:History of Topics in Special Relativity/mathsource|lagu80}} *{{#section:History of Topics in Special Relativity/mathsource|lagu82}} *{{#section:History of Topics in Special Relativity/mathsource|lie71a}} *{{#section:History of Topics in Special Relativity/mathsource|lie71b}} *{{#section:History of Topics in Special Relativity/mathsource|lie84}} *{{#section:History of Topics in Special Relativity/mathsource|liou50}} *{{#section:History of Topics in Special Relativity/mathsource|poc91}} *{{#section:History of Topics in Special Relativity/mathsource|rib70}} *{{#section:History of Topics in Special Relativity/mathsource|schef99}} *{{#section:History of Topics in Special Relativity/mathsource|smi00}} *{{#section:History of Topics in Special Relativity/mathsource|ste83}} ===Historical relativity sources=== {{reflist|3|group=R}} {{#section:History of Topics in Special Relativity/relsource|bate10elec}} {{#section:History of Topics in Special Relativity/relsource|bate12}} {{#section:History of Topics in Special Relativity/relsource|car12}} {{#section:History of Topics in Special Relativity/relsource|cunn10}} {{#section:History of Topics in Special Relativity/relsource|klein10}} {{#section:History of Topics in Special Relativity/relsource|poi21}} ===Secondary sources=== {{reflist|3}} {{#section:History of Topics in Special Relativity/secsource|L5}} [[Category:Special Relativity]] [[Category:History of Physics]] pjv2ehuaan9h851gu4bpjq7lgx8catj 2414076 2414075 2022-08-13T11:28:48Z D.H 52339 /* Lorentz transformation via sphere transformation */ wikitext text/x-wiki {{../Lorentz transformation (header)}} ==Lorentz transformation via sphere transformation== If one only requires the invariance of the light cone represented by the differential equation <math>-dx_{0}^{2}+\dots+dx_{n}^{2}=0</math>, which is the same as asking for the most general transformation that changes spheres into spheres, the Lorentz group can be extended by adding dilations represented by the factor λ. The result is the group Con(1,p) of spacetime [[w:conformal transformation]]s in terms of [[w:special conformal transformation]]s and inversions producing the relation :<math>-dx_{0}^{2}+\dots+dx_{n}^{2}=\lambda\left(-dx_{0}^{\prime2}+\dots+dx_{n}^{\prime2}\right)</math>. One can switch between two representations of this group by using an imaginary sphere radius coordinate ''x₀=iR'' with the interval <math>dx_{0}^{2}+\dots+dx_{n}^{2}</math> related to conformal transformations, or by using a real radius coordinate ''x₀=R'' with the interval <math>-dx_{0}^{2}+\dots+dx_{n}^{2}</math> related to [[#Lie|Lie's (1871)]] sphere transformation (or [[w:spherical wave transformation]]s) in terms of [[w:contact transformation]]s preserving circles and spheres. It was shown by [[#Bateman|Bateman & Cunningham (1909–1910)]], that the group Con(1,3) is the most general one leaving invariant the equations of Maxwell's electrodynamics. It turns out that Con(1,3) is isomorphic to the [[w:special orthogonal group]] SO(2,4), and contains the Lorentz group SO(1,3) as a subgroup by setting λ=1. More generally, Con(q,p) is isomorphic to SO(q+1,p+1) and contains SO(q,p) as subgroup.<ref>Schottenloher (2008), section 2.2</ref> This implies that Con(0,p) is isomorphic to the Lorentz group of arbitrary dimensions SO(1,p+1). Consequently, the conformal group in the plane Con(0,2) – known as the group of [[w:Möbius transformation]]s – is isomorphic to the Lorentz group SO(1,3).<ref>Kastrup (2008), section 2.4.1</ref><ref>Schottenloher (2008), section 2.3</ref> This can be seen using tetracyclical coordinates satisfying the form <math>-x_{0}^{2}+x_{1}^{2}+x_{2}^{2}+x_{3}^{2}=0</math>, which were discussed by [[#Klein3|Pockels (1891), Klein (1893), Bôcher (1894)]]. The relation between Con(1,3) and the Lorentz group was noted by [[#Bateman|Bateman & Cunningham (1909–1910)]] and others. (For a different take on the Möbius group, see also [[../Lorentz transformation (Möbius)|E:Lorentz transformation via Cayley–Klein parameters, Möbius and spin transformations]]). A subgroup of Lie's group of sphere transformations is the [[w:Spherical wave transformation#Transformation by reciprocal directions|Laguerre group]] (or ''group of transformations by reciprocal directions'') dealing with oriented spheres, planes and lines, which was already implicit in the work of [[#Ribaucour|Ribaucour (1870)]], [[#Lie|Lie (1871)]], [[#Darboux|Darboux (1873)]]. It's generated by the Laguerre inversion introduced by [[#Laguerre|Laguerre (1882)]] and discussed by [[#Darboux|Darboux (1887)]] and [[#Smith|Smith (1900)]] leaving invariant <math>X^{2}+Y^{2}+Z^{2}-R^{2}</math> with ''R'' as radius, thus the Laguerre group is isomorphic to the Lorentz group. A similar concept was studied by [[#Scheffers|Scheffers (1899)]] in terms of contact transformations. [[#Stephanos|Stephanos (1883)]] argued that Lie's geometry of oriented spheres in terms of contact transformations, as well as the special case of the transformations of oriented planes into each other (such as by Laguerre), provides a geometrical interpretation of Hamilton's [[w:biquaternion]]s. The [[w:group isomorphism]] between the Laguerre group and Lorentz group was pointed out by [[#Bateman|Bateman (1910), Cartan (1912, 1915/55), Poincaré (1912/21)]] and others.<ref>Coolidge (1916), p. 370</ref><ref name="ReferenceA">Cartan & Fano (1915/55), sections 14–15</ref> The Laguerre inversion was written in the following ways: {{NumBlk|:|<math>\begin{matrix}-R^{2}+X^{2}=-R^{\prime2}+X^{\prime2}\\ \hline \begin{align}R' & =-R\frac{1+a^{2}}{1-a^{2}}+X\frac{2a}{1-a^{2}}\\ X' & =-R\frac{2a}{1-a^{2}}+X\frac{1+a^{2}}{1-a^{2}} \end{align} \end{matrix}</math>|{{equationRef|1}}}} or {{NumBlk|:|<math>\begin{matrix}-R^{2}+X^{2}=-R^{\prime2}+X^{\prime2}\\ \hline \begin{align}R' & =-\frac{1}{2}\left(k+\frac{1}{k}\right)R+\frac{1}{2}\left(k-\frac{1}{k}\right)X\\ X' & =-\frac{1}{2}\left(k-\frac{1}{k}\right)R+\frac{1}{2}\left(k+\frac{1}{k}\right)X \end{align} \end{matrix}</math>|{{equationRef|2}}}} Laguerre inversions (1, 2) are antichronous Lorentz transformations, which become orthochronous by changing the sign of <math>R'</math>. A special case of formulas (1, 2) with <math>a=k=\sqrt{-1}</math> was already given by [[#Bonnet|Bonnet (1856)]]. Formula (1) was given by [[#Laguerre|Laguerre (1882)]] and [[#Darboux|Darboux (1887)]], formula (2) by [[#Smith|Smith (1900)]]. Laguerre transformations in trigonometric form were given by [[#Scheffers|Scheffers (1899)]]. Furthermore, setting <math>v=\tfrac{2a}{1+a^{2}}=\tfrac{k^{2}-1}{k^{2}+1}</math> together with <math>\cos\alpha'=\tfrac{X'}{-R'}</math> and <math>\cos\alpha=\tfrac{X}{R}</math> gives: {{NumBlk|:|<math>\cos\alpha'=\frac{\cos\alpha-v}{1-v\cos\alpha}\quad\text{or}\quad\tan\frac{\alpha'}{2}=\sqrt{\frac{1+v}{1-v}}\tan\frac{\alpha}{2}</math>|{{equationRef|3}}}} Formula (3) was already used by [[#Darboux|Darboux (1873)]] as a sphere transformation, and in 1881 he showed that it can also be used to perform Laguerre transformations of planes. In special relativity, it turns out that formula (3) describes the aberration of light, see [[../Lorentz transformation (velocity)#Velocity addition and aberration|E:velocity addition and aberration]]. ==Historical notation== ==={{anchor|Bonnet}} Bonnet (1856) === [[w:Pierre Ossian Bonnet]] (1856) defined a reciprocal transformation preserving lines of curvatures. He noted that his transformation implies the following relation between curvature radii <math>\rho,\rho_{1}</math> and ordinates <math>\zeta,\zeta_{1}</math> of the respective curvature centers:<ref group=M>Bonnet (1856), p. 487</ref> :<math>\rho_{1}=i\zeta,\quad\rho=-i\zeta_{1}</math> where <math>i=\sqrt{-1}</math> <p style="background-color:Beige;border:1px solid black">Bonnet's transformation produces <math>\rho^{2}-\zeta^{2}=\rho_{1}^{2}-\zeta_{1}^{2}</math> and represents a special case of Laguerre inversion (or Lorentz transformation) ({{equationNote|1}}, {{equationNote|2}}) with <math>a=k=\sqrt{-1}</math>. [[#Lie|Lie (1871)]], [[#Darboux|Darboux (1887)]] and [[#Smith|Smith (1900)]] all noticed that Bonnet's transformation is a special case of Lie's and Laguerre's transformations.</p> ==={{anchor|Ribaucour}} Ribaucour (1870) === [[w:Albert Ribaucour]] (1870),<ref group=M>Ribaucour (1870). pp. 330-333</ref> defined what was later called “Ribaucour transformations” preserving lines of curvature: :p. 330: If circles are normal to three surfaces, they are normal to a family of surfaces belonging to a triply orthogonal system. This results in a class of orthogonal triple systems which I will propose to call cyclic systems, intimately linked to the deformation of surfaces. Given a surface (A), we can propose to seek all the cyclic systems which derive from it; the <math>ds^{2}</math> of this surface being put in the form <math>ds^{2}=\lambda^{2}.dx\ dy</math> [...] :p. 332: If spheres have their contact chords normal to surfaces, the circles passing through the centers of these spheres and their points of contact with their enveloping surfaces are normal to an infinity of surfaces forming part of a cyclic system. [...] If surfaces are part of an orthogonal system, the osculating circles of their orthogonal trajectories corresponding to all the points of one of these surfaces are normal to a family of surfaces belonging to a cyclic system. [...] I will point out the simple case where (A) is a plane, a case which leads to a general transformation of the surfaces with correspondence of the lines of curvature [...]. <p style="background-color:Beige;border:1px solid black">Referring to p. 332 of Ribaucour's paper, [[#Darboux|Darboux (1887)]] and [[#Bateman|Bateman (1910)]] argued that Ribaucour anticipated both [[#Lie|Lie (1871)]] and [[#Laguerre|Laguerre (1880)]] in formulating the “transformation by reciprocal directions”, which in Darboux's representation led to algebraic expressions identical to Laguerre inversion (or Lorentz transformation) ({{equationNote|1}}) and ({{equationNote|3}}).</p> ==={{anchor|Lie}} Lie (1871)=== In several papers between 1847 and 1850 it was shown by [[w:Joseph Liouville]]<ref group=M>Liouville (1847)</ref> that the relation ''λ(δx²+δy²+δz²)'' is invariant under the group of [[w:conformal transformation]]s generated by [[w:Spherical wave transformation#Transformation by reciprocal radii|w:inversions]] transforming spheres into spheres, which can be related [[w:special conformal transformation]]s or [[w:Möbius transformation]]s. (The conformal nature of the linear fractional transformation <math>\tfrac{a+bz}{c+dz}</math> of a complex variable <math>z</math> was already discussed by Euler (1777)).<ref group=M>Euler (1777), p. 140</ref><ref name=kastrup>Kastrup (2008), section 2.1</ref> Liouville's theorem was extended to all dimensions by [[w:Sophus Lie]] (1871a).<ref group=M name=lie1>Lie (1871), pp. 199–209</ref><ref>Kastrup (2008), section 2.3</ref> In addition, Lie described a manifold whose elements can be represented by spheres, where the last coordinate ''y_n+1'' can be related to an imaginary radius by ''iy_n+1'':<ref group=M name=lie1 /> :<math>\begin{matrix}\sum_{i=1}^{i=n} (x_i-y_i)^2+y_{n+1}^2=0 \\ \downarrow\\ \sum_{i=1}^{i=n+1} (y_i^{\prime}-y_i^{\prime\prime})^2=0 \end{matrix}</math> If the second equation is satisfied, two spheres ''y′'' and ''y″'' are in contact. Lie then defined the correspondence between [[w:Contact geometry|w:contact transformations]] in ''R_n'' and conformal point transformations in ''R_n+1'': The sphere of space ''R_n'' consists of ''n+1'' parameter (coordinates plus imaginary radius), so if this sphere is taken as the element of space ''R_n'', it follows that ''R_n'' now corresponds to ''R_n+1''. Therefore, any transformation (to which he counted [[../Lorentz transformation (imaginary)#Lorentz transformation via orthogonal transformation|E:orthogonal transformations]] and inversions) leaving invariant the condition of contact between spheres in ''R_n'', corresponds to the conformal transformation of points in ''R_n+1''. He pointed out that conformal point transformations consist of motions (such as [[w:rigid transformation]]s and orthogonal transformations), similarity transformations, and inversions.<ref group=M>Lie (1871/72), first footnote on p. 186</ref> <p style="background-color:Beige;border:1px solid black">As shown by [[#Bateman|Bateman and Cunningham (1909)]], the spacetime conformal group Con(1,3) of "[[w:spherical wave transformation]]s" corresponds to the transformations of Lie's sphere geometry in which the radius indicates the fourth coordinate, while the Lorentz group SO(1,3) is a subgroup of Con(1,3). It's also known that the Möbius group and Laguerre group, which are both isomorphic to the Lorentz group, are subgroups of Lie's sphere transformations group.</p> In the same paper, Lie also mentioned the “well known fact” that “parallel transformations” (dilatations having the property of transforming planes to parallel planes) preserve lines of curvature, and he alluded to [[#Bonnet|Bonnet's (1856)]] transformation as an example.<ref group=M>Lie (1871/72), p. 184</ref> Generally, all of the discussed transformations that preserve lines of curvature are either inversions or parallel transformations.<ref group=M>Lie (1871/72), p. 186</ref> In a footnote he specifically remarked that line transformations under which "(const=0)" remains unchanged, give all transformations of ''R'' by which surfaces of common spherical image pass into other such surfaces, and that the new spherical image emerges from the former by a conformal point transformation of the image-sphere, and that [[#Bonnet|Bonnet's (1856)]] transformation belongs here.<ref group=M>Lie (1871/72), second footnote on p. 186</ref> <p style="background-color:Beige;border:1px solid black">Lie himself (1884)<ref group=M>Lie (1884), footnote on p. 541</ref> pointed out that his remarks indicate the same transformation group treated in more recent works of [[#Laguerre|Laguerre (1880-82)]] and [[#Stephanos|Stephanos (1882)]]. Consequently, [[#Smith|Smith (1900)]] credits Lie as being the first one to allude to the existence of the (extended) Laguerre group, transforming spheres into spheres and planes into planes. On the other hand, [[#Darboux|Darboux (1887)]] pointed out that the transformation by reciprocal directions was already anticipated by [[#Ribaucour|Ribaucour (1870)]] even before Lie.</p> ==={{anchor|Klein3}} Klein, Pockels, Bôcher (1871-91)=== In relation to line geometry, [[w:Felix Klein]] (1871/72)<ref group=M>Klein (1871/72), p. 268</ref> used coordinates satisfying the condition <math>s_{1}^{2}+s_{2}^{2}+s_{2}^{2}+s_{2}^{2}+s_{5}^{2}=0</math>. They were introduced in 1868 (belatedly published in 1873) by [[w:Gaston Darboux]]<ref group=M>Darboux (1873), p. 137</ref> as a system of five coordinates in ''R₃'' (later called "pentaspherical" coordinates) in which the last coordinate is imaginary. [[w:Sophus Lie]] (1871)<ref group=M>Lie (1871), p. 208</ref> more generally used ''n+2'' coordinates in ''R_n'' (later called "polyspherical" coordinates) satisfying <math>\scriptstyle \sum_{i=1}^{i=n+2}x_{i}^{2}=0</math> in which the last coordinate is imaginary, as a means to discuss conformal transformations generated by inversions. These simultaneous publications can be explained by the fact that Darboux, Lie, and Klein corresponded with each other by letter. When the last coordinate is defined as real, the corresponding polyspherical coordinates satisfy the form of a sphere. Initiated by lectures of Klein between 1889–1890, his student [[w:Friedrich Carl Alwin Pockels]] (1891) used such real coordinates, emphasizing that all of these coordinate systems remain invariant under conformal transformations generated by inversions:<ref group=M>Pockels (1891), pp. 197–206</ref> :<math>x_1^2+x_2^2+\cdots+x_{n+1}^2-x_{n+2}^2=0 \text{ or } \sum_1^{n+1} x_h^2-x_{n+2}^2=0</math> Special cases were described by Klein (1893):<ref group=M>Klein (1893c), pp. 200ff (pentaspherical), pp. 373ff (tetracyclical)</ref> :<math>y_1^2+y_2^2+y_3^2+y_4^2-y_5^2=0</math> (pentaspherical). :<math>x_1^2+x_2^2+x_3^2-x_4^2=0</math> (tetracyclical). Both systems were also described by [[w:Maxime Bôcher]] (1894) in an expanded version of a thesis supervised by Klein.<ref group=M>Bôcher (1894), pp. 30–34, 40–43</ref> <p style="background-color:Beige;border:1px solid black">Polyspherical coordinates indicate that the conformal group {{nowrap|Con(0,p)}} is isomorphic to the Lorentz group SO(1,p+1).<ref>Kastrup (2008), p. 22</ref> For instance, Con(0,2) – known as Möbius group – is related to tetracyclical coordinates satisfying <math>x_{1}^{2}+x_{2}^{2}+x_{3}^{2}-x_{4}^{2}=0</math>, which is nothing other than the Lorentz interval invariant under the Lorentz group SO(1,3).</p> ==={{anchor|Darboux}} Darboux (1873-87)=== In 1873, [[w:Gaston Darboux]] stated the following proposition:<ref group=M>Darboux (1873), pp. 254-255.</ref> :Given a surface <math>\left(\Sigma\right)</math>, we add a fixed sphere <math>\left({\rm S}\right)</math> to it, and we construct all spheres tangent to the surface and intersecting <math>\left({\rm S}\right)</math> at a constant angle <math>\alpha</math>. Through the intersection of each of these spheres and <math>\left({\rm S}\right)</math> new spheres pass intersecting <math>\left({\rm S}\right)</math> at a constant angle <math>\beta</math>. These new spheres envelop a surface <math>\left(\Sigma_{1}\right)</math>, corresponding point by point to <math>\left(\Sigma\right)</math> with conservation of lines of curvature. The corresponding points on the two surfaces are on circles normal both to the two surfaces and to the sphere <math>\left({\rm S}\right)</math>. which he generalized by making a second proposition:<ref group=M>Darboux (1873), footnote on p. 255.</ref> :Consider a surface <math>\left(\Sigma\right)</math>, envelope of a series of variable spheres <math>\left(\rm U\right)</math> intersecting under any angles the sphere <math>\left(\rm S\right)</math>. At each of the spheres <math>\left(\rm U\right)</math> intersecting <math>\left(\rm S\right)</math> at an angle I call <math>\varphi</math> we match a sphere <math>\left(\rm U_1\right)</math> passing through the intersection of <math>\left(\rm S\right)</math> and from <math>\left(\rm U \right)</math>, and intersecting <math>\left(\rm S\right)</math> at an angle <math>\varphi_1</math> determined by equation ::<math>\frac{\cos\varphi-\cos\varphi_{1}}{1-\cos\varphi\cos\varphi_{1}}=h</math> :Then the new spheres <math>\left(\rm U_1\right)</math> envelop a surface <math>\left(\Sigma_1\right)</math> which corresponds point by point at <math>\left(\Sigma\right)</math> with curvature lines preserved. If we subject the spheres <math>\left(\rm U\right)</math> tangent to <math>\left(\Sigma \right)</math> to cut <math>\left(\rm S\right)</math> under a constant angle, <math>\varphi</math> will be constant; it will be the same for <math>\varphi_1</math>, by virtue of the previous equation, and we find the theorem given above. » <p style="background-color:Beige;border:1px solid black">This is equivalent to Laguerre transformation (or Lorentz transformation) ({{equationNote|3}}) with <math>h=\beta</math>.</p> In 1881 he quoted his above propositions, gave priority to the first one to [[#Ribaucour|Ribaucour (1870)]], and then showed that Laguerre's transformation of reciprocal directions is included as well:<ref group=M>Darboux (1881), p. 286f.</ref> :This proposal gave a new means of realizing a mode of transformation of surfaces with preservation of the lines of curvature, to which [[#Ribaucour|Ribaucour]] had devoted a few lines in a Communication made to the Academy in 1870 ''sur la deformation des surfaces''. :[..] Suppose, in particular, that the sphere <math>\left(\rm S\right)</math> reduces to a plane <math>\left(\pi\right)</math>. Then to any plane <math>\left(\rm P\right)</math> will correspond a plane <math>\left(\rm P'\right)</math> passing through the intersection of <math>\left(\pi\right)</math> and <math>\left(\rm P\right)</math>, and the angles <math>\varphi,\varphi'</math> that the planes <math>\left(\rm P\right)</math>, <math>\left(\rm P'\right)</math> make with <math>\left(\pi\right)</math> will be linked by relation (1). It is not difficult to recognize, in this transformation from one plane to another, that which has recently been studied by [[#Laguerre|Laguerre]] under the name of ''transformation by reciprocal directions''. We see that it is included in the transformation of spheres which is defined by our second proposition. I have recalled these results only to arrive at the proposition which is the main object of this Communication. I will show, in accordance with a general theorem of [[#Lie|Lie]], that the transformation first proposed by [[#Ribaucour|Ribaucour]] boils down to dilatations (transition from a surface to the parallel surface) and to transformations by reciprocal vector rays. He went on to rewrite his 1873 equation as:<ref group=M>Darboux (1881), footnote on p. 287</ref> :<math>\mathrm{tang}\frac{\varphi}{2}=\mathrm{tang}\frac{\varphi_{1}}{2}\sqrt{\frac{1-h}{1 +h}}</math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Laguerre transformation (or Lorentz transformation) ({{equationNote|3}}) with <math>h=\beta</math>.</p> In 1887, Darboux gave a much more detailed account. For instance, he re-derived and extended the transformation of oriented half-lines given by [[#Laguerre|Laguerre (1882)]] using coordinates ''x,y,z,R'':<ref group=M>Darboux (1887), p. 254</ref> :<math>\begin{matrix}x^{\prime2}+y^{\prime2}+z^{\prime2}-R^{\prime2}=x^{2}+y^{2}+z^{2}-R^{2}\\ \hline \begin{align}x' & =x, & z' & =\frac{1+k^{2}}{1-k^{2}}z-\frac{2kR}{1-k^{2}},\\ y' & =y, & R' & =\frac{2kz}{1-k^{2}}-\frac{1+k^{2}}{1-k^{2}}R, \end{align} \end{matrix}</math> or <math>\begin{align}z'+R' & =\frac{1+k}{1-k}(z-R)\\ z'-R' & =\frac{1-k}{1+k}(z+R) \end{align}</math> He went on to derive expressions and theorems similar to those given by him in 1873, and added that [[#Bonnet|Bonnet's (1856)]] transformation is a special case.<ref group=M>Darboux (1887), p. 256</ref> <p style="background-color:Beige;border:1px solid black">This is equivalent to Laguerre inversion (or Lorentz transformation) ({{equationNote|1}}).</p> Regarding the history of such transformations (before Laguerre's research) he wrote:<ref group=M>Darboux (1887), footnote on p. 259</ref> :In the memoir already quoted, inserted in volume V of ''Mathematische Annalen'', [[#Lie|Lie]] has made known all the contact transformations which preserve the lines of curvature; he even pointed out (p. 186) the particular case of transformation by reciprocal directions; but this transformation had already been given in different works by [[#Ribaucour|Ribaucour]]. See, in particular, Ribaucour's note ''sur la deformation des surfaces (Comptes rendus, t. LXX, p. 332, 1870)''. In a different form, it was the subject of the author's studies published in Notes V and IX of ''Mémoire sur une classe remarquable de courbes et de surfaces algébriques'', 1873. ==={{anchor|Laguerre}} Laguerre (1880-82) === A systematic formulation of a geometry of orientation was given by [[w:Edmond Laguerre]] (1880), including geometric transformations of oriented planes into oriented planes and oriented spheres into oriented spheres, which he called "[[w:Spherical wave transformation#Transformation by reciprocal directions|w:transformation by reciprocal directions]]".<ref group=M>Laguerre (1880)</ref> Besides the focus on the transformation of planes, a distinguishing feature to previous authors was the employment of the concept of orientation (i.e. attributing a certain sign to lines and radii) which became an indispensable tool in Lie sphere geometry and Laguerre geometry. <p style="background-color:Beige;border:1px solid black">Laguerre's transformations form a group (Laguerre group) which is isomorphic to the Lorentz group, and forms a subgroup of [[#Lie|Lie's (1871)]] contact transformations of spheres.</p> In 1882 he developed the “transformation of oriented half-lines” which was later called "Laguerre inversion", using the following algebraic formulation (''R'' being the radius and ''D'' the distance of its center to the axis):<ref group=M>Laguerre (1882), pp. 550–551.</ref> :<math>\left.\begin{align}D' & =\frac{D\left(1+\alpha^{2}\right)-2\alpha R}{1-\alpha^{2}}\\ R' & =\frac{2\alpha D-R\left(1+\alpha^{2}\right)}{1-\alpha^{2}} \end{align} \right|\begin{align}D^{2}-D^{\prime2} & =R^{2}-R^{\prime2}\\ D-D' & =\alpha(R-R')\\ D+D' & =\frac{1}{\alpha}(R+R') \end{align} </math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Laguerre inversion (or Lorentz transformation) ({{equationNote|1}}). The Laguerre inversions are generators of the Laguerre group.</p> ==={{anchor|Stephanos}} Stephanos (1883)=== [[w:Cyparissos Stephanos]] (1883)<ref group=M>Stephanos (1883), p. 590ff</ref> showed that Hamilton's biquaternion ''a₀+a₁ι₁+a₂ι₂+a₃ι₃'' can be interpreted as an oriented sphere in terms of [[#Lie|Lie's sphere geometry (1871)]], having the vector ''a₁ι₁+a₂ι₂+a₃ι₃'' as its center and the scalar <math>a_{0}\sqrt{-1}</math> as its radius. Its norm <math>a_{1}^{2}+a_{2}^{2}+a_{3}^{2}+a_{4}^{2}</math> is thus equal to the power of a point of the corresponding sphere. In particular, the norm of two quaternions ''N(Q₁-Q₂)'' (the corresponding spheres are in contact with ''N(Q₁-Q₂)=0'') is equal to the tangential distance between two spheres. The general contact transformation between two spheres then can be given by a [[w:homography]] using 4 arbitrary quaternions ''A,B,C,D'' and two variable quaternions ''X,Y'':<ref group=M>Stephanos (1883), p. 592</ref><ref>Cartan & Study (1908), p. 460</ref><ref>Rothe (1916), p. 1399</ref> :<math>XAY+XB+CY+D=0</math> (or <math>X=-\frac{CY+D}{AY+B}</math>). Stephanos pointed out that the special case ''A=0'' denotes transformations of oriented planes (see [[#Laguerre|Laguerre (1882)]]). <p style="background-color:Beige;border:1px solid black">The Lorentz group {{nowrap|SO(1,3)}} is a subgroup of the conformal group {{nowrap|Con(1,3)}} in terms of [[#Lie|Lie's (1871)]] transformations of oriented spheres in which the radius indicates the fourth coordinate. The Lorentz group is isomorphic to the group of [[#Laguerre|Laguerre's (1880)]] transformation of oriented planes.</p> ==={{anchor|Scheffers}} Scheffers (1899)=== [[w:Georg Scheffers]] (1899) synthetically determined all ''finite'' [[w:contact transformation]]s preserving circles in the plane, consisting of dilatations, inversions, and the following one preserving circles and lines (compare with Laguerre inversion by [[#Laguerre|Laguerre (1882)]] and [[#Darboux|Darboux (1887)]]):<ref group=M>Scheffers (1899), p. 158</ref> :<math>\begin{matrix}\sigma^{\prime2}-\rho^{\prime2}=\sigma^{2}-\rho^{2}\\ \hline \rho'=\frac{\rho}{\cos\omega}+\sigma\tan\omega,\quad\sigma'=\rho\tan\omega+\frac{\sigma}{\cos\omega} \end{matrix}</math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Laguerre transformation (or Lorentz transformation) ({{equationNote|1}}) by the identity <math>\sin\omega=\beta=\frac{2a}{1+a^{2}}=\frac{k^{2}-1}{k^{2}+1}</math>.</p> ==={{anchor|Smith}} Smith (1900)=== [[w:Percey F. Smith]] (1900) followed [[#Laguerre|Laguerre (1882)]] and [[#Darboux|Darboux (1887)]] and defined the Laguerre inversion as follows:<ref group=M>Smith (1900), p. 159</ref> :<math>\begin{matrix}p^{\prime2}-p^{2}=R^{\prime2}-R^{2}\\ \hline \kappa=\frac{R'-R}{p'-p}\\ p'=\frac{\kappa^{2}+1}{\kappa^{2}-1}p-\frac{2\kappa}{\kappa^{2}-1}R,\quad R'=\frac{2\kappa}{\kappa^{2}-1}p-\frac{\kappa^{2}+1}{\kappa^{2}-1}R \end{matrix}</math> He added that [[#Bonnet|Bonnet's (1856)]] transformation is a special case with <math>\kappa^{2}=-1</math>, and he also gave credit to [[#Lie|Lie (1871)]] for defining the corresponding "group of the geometry of reciprocal directions". <p style="background-color:Beige;border:1px solid black">This is equivalent to Laguerre inversion (or Lorentz transformation) ({{equationNote|2}}).</p> ==={{anchor|Bateman}} Bateman and Cunningham (1909–1910)=== In line with [[#Lie|Lie's (1871)]] research on the relation between sphere transformations with an imaginary radius coordinate and 4D conformal transformations, it was pointed out by [[w:Harry Bateman]] and [[w:Ebenezer Cunningham]] (1909–1910), that by setting ''u=ict'' as the imaginary fourth coordinates one can produce spacetime conformal transformations. Not only the quadratic form <math>\lambda\left(dx^{2}+dy^{2}+dz^{2}+du^{2}\right)</math>, but also [[w:Maxwells equations]] are covariant with respect to these transformations, irrespective of the choice of λ. These variants of conformal or Lie sphere transformations were called [[w:spherical wave transformation]]s by Bateman.<ref group=R>Bateman (1909/10), pp. 223ff</ref><ref group=R>Cunningham (1909/10), pp. 77ff</ref> However, this covariance is restricted to certain areas such as electrodynamics, whereas the totality of natural laws in inertial frames is covariant under the [[w:Lorentz group]].<ref group=R>Klein (1910)</ref> In particular, by setting λ=1 the Lorentz group {{nowrap|SO(1,3)}} can be seen as a 10-parameter subgroup of the 15-parameter spacetime conformal group {{nowrap|Con(1,3)}}. Bateman (1910/12)<ref>Bateman (1910/12), pp. 358–359</ref> also alluded to the identity between the [[#Laguerre|Laguerre inversion]] and the Lorentz transformations. In general, the isomorphism between the Laguerre group and the Lorentz group was pointed out by [[w:Élie Cartan]] (1912, 1915/55),<ref name="ReferenceA"/><ref group=R>Cartan (1912), p. 23</ref> [[w:Henri Poincaré]] (1912/21)<ref group=R>Poincaré (1912/21), p. 145</ref> and others. ==References== ===Historical mathematical sources=== {{reflist|3|group=M}} *{{#section:History of Topics in Special Relativity/mathsource|boch94pot}} *{{#section:History of Topics in Special Relativity/mathsource|bon56}} *{{#section:History of Topics in Special Relativity/mathsource|dar73}} *{{#section:History of Topics in Special Relativity/mathsource|dar81cou}} *{{#section:History of Topics in Special Relativity/mathsource|dar87cou}} *{{#section:History of Topics in Special Relativity/mathsource|eul77}} *{{#section:History of Topics in Special Relativity/mathsource|klei72a}} *{{#section:History of Topics in Special Relativity/mathsource|klei93c}} *{{#section:History of Topics in Special Relativity/mathsource|lagu80}} *{{#section:History of Topics in Special Relativity/mathsource|lagu82}} *{{#section:History of Topics in Special Relativity/mathsource|lie71a}} *{{#section:History of Topics in Special Relativity/mathsource|lie71b}} *{{#section:History of Topics in Special Relativity/mathsource|lie84}} *{{#section:History of Topics in Special Relativity/mathsource|liou50}} *{{#section:History of Topics in Special Relativity/mathsource|poc91}} *{{#section:History of Topics in Special Relativity/mathsource|rib70}} *{{#section:History of Topics in Special Relativity/mathsource|schef99}} *{{#section:History of Topics in Special Relativity/mathsource|smi00}} *{{#section:History of Topics in Special Relativity/mathsource|ste83}} ===Historical relativity sources=== {{reflist|3|group=R}} {{#section:History of Topics in Special Relativity/relsource|bate10elec}} {{#section:History of Topics in Special Relativity/relsource|bate12}} {{#section:History of Topics in Special Relativity/relsource|car12}} {{#section:History of Topics in Special Relativity/relsource|cunn10}} {{#section:History of Topics in Special Relativity/relsource|klein10}} {{#section:History of Topics in Special Relativity/relsource|poi21}} ===Secondary sources=== {{reflist|3}} {{#section:History of Topics in Special Relativity/secsource|L5}} [[Category:Special Relativity]] [[Category:History of Physics]] qh1urrn92m47jvgi30jmwue5wwht4so 2414077 2414076 2022-08-13T11:34:08Z D.H 52339 /* Lorentz transformation via sphere transformation */ wikitext text/x-wiki {{../Lorentz transformation (header)}} ==Lorentz transformation via sphere transformation== If one only requires the invariance of the light cone represented by the differential equation <math>-dx_{0}^{2}+\dots+dx_{n}^{2}=0</math>, which is the same as asking for the most general transformation that changes spheres into spheres, the Lorentz group can be extended by adding dilations represented by the factor λ. The result is the group Con(1,p) of spacetime [[w:conformal transformation]]s in terms of [[w:special conformal transformation]]s and inversions producing the relation :<math>-dx_{0}^{2}+\dots+dx_{n}^{2}=\lambda\left(-dx_{0}^{\prime2}+\dots+dx_{n}^{\prime2}\right)</math>. One can switch between two representations of this group by using an imaginary sphere radius coordinate ''x₀=iR'' with the interval <math>dx_{0}^{2}+\dots+dx_{n}^{2}</math> related to conformal transformations, or by using a real radius coordinate ''x₀=R'' with the interval <math>-dx_{0}^{2}+\dots+dx_{n}^{2}</math> related to [[#Lie|Lie's (1871)]] sphere transformation (or [[w:spherical wave transformation]]s) in terms of [[w:contact transformation]]s preserving circles and spheres. It was shown by [[#Bateman|Bateman & Cunningham (1909–1910)]], that the group Con(1,3) is the most general one leaving invariant the equations of Maxwell's electrodynamics. It turns out that Con(1,3) is isomorphic to the [[w:special orthogonal group]] SO(2,4), and contains the Lorentz group SO(1,3) as a subgroup by setting λ=1. More generally, Con(q,p) is isomorphic to SO(q+1,p+1) and contains SO(q,p) as subgroup.<ref>Schottenloher (2008), section 2.2</ref> This implies that Con(0,p) is isomorphic to the Lorentz group of arbitrary dimensions SO(1,p+1). Consequently, the conformal group in the plane Con(0,2) – known as the group of [[w:Möbius transformation]]s – is isomorphic to the Lorentz group SO(1,3).<ref>Kastrup (2008), section 2.4.1</ref><ref>Schottenloher (2008), section 2.3</ref> This can be seen using tetracyclical coordinates satisfying the form <math>-x_{0}^{2}+x_{1}^{2}+x_{2}^{2}+x_{3}^{2}=0</math>, which were discussed by [[#Klein3|Pockels (1891), Klein (1893), Bôcher (1894)]]. The relation between Con(1,3) and the Lorentz group was noted by [[#Bateman|Bateman & Cunningham (1909–1910)]] and others. (For a different take on the Möbius group, see also [[../Lorentz transformation (Möbius)|E:Lorentz transformation via Cayley–Klein parameters, Möbius and spin transformations]]). A subgroup of Lie's group of sphere transformations is the [[w:Spherical wave transformation#Transformation by reciprocal directions|Laguerre group]] (or ''group of transformations by reciprocal directions'') dealing with oriented spheres, planes and lines, which was already implicit in the work of [[#Ribaucour|Ribaucour (1870)]], [[#Lie|Lie (1871)]], [[#Darboux|Darboux (1873)]]. It's generated by the Laguerre inversion introduced by [[#Laguerre|Laguerre (1882)]] and discussed by [[#Darboux|Darboux (1887)]] and [[#Smith|Smith (1900)]] leaving invariant <math>X^{2}+Y^{2}+Z^{2}-R^{2}</math> with ''R'' as radius, thus the Laguerre group is isomorphic to the Lorentz group. A similar concept was studied by [[#Scheffers|Scheffers (1899)]] in terms of contact transformations. [[#Stephanos|Stephanos (1883)]] argued that Lie's geometry of oriented spheres in terms of contact transformations, as well as the special case of the transformations of oriented planes into each other (such as by Laguerre), provides a geometrical interpretation of Hamilton's [[w:biquaternion]]s. The [[w:group isomorphism]] between the Laguerre group and Lorentz group was pointed out by [[#Bateman|Bateman (1910), Cartan (1912, 1915/55), Poincaré (1912/21)]] and others.<ref>Coolidge (1916), p. 370</ref><ref name="ReferenceA">Cartan & Fano (1915/55), sections 14–15</ref> The Laguerre inversions are antichronous Lorentz transformations, which become orthochronous by changing the sign of <math>R'</math>. It was written in the following ways: {{NumBlk|:|<math>\begin{matrix}-R^{2}+X^{2}=-R^{\prime2}+X^{\prime2}\\ \hline \begin{align}R' & =-R\frac{1+a^{2}}{1-a^{2}}+X\frac{2a}{1-a^{2}}\\ X' & =-R\frac{2a}{1-a^{2}}+X\frac{1+a^{2}}{1-a^{2}} \end{align} \end{matrix}</math>|{{equationRef|1}}}} or {{NumBlk|:|<math>\begin{matrix}-R^{2}+X^{2}=-R^{\prime2}+X^{\prime2}\\ \hline \begin{align}R' & =-\frac{1}{2}\left(k+\frac{1}{k}\right)R+\frac{1}{2}\left(k-\frac{1}{k}\right)X\\ X' & =-\frac{1}{2}\left(k-\frac{1}{k}\right)R+\frac{1}{2}\left(k+\frac{1}{k}\right)X \end{align} \end{matrix}</math>|{{equationRef|2}}}} A special case of formulas (1, 2) with <math>a=k=\sqrt{-1}</math> was already given by [[#Bonnet|Bonnet (1856)]]. Formula (1) was given by [[#Laguerre|Laguerre (1882)]] and [[#Darboux|Darboux (1887)]], formula (2) by [[#Smith|Smith (1900)]]. Laguerre transformations in trigonometric form were given by [[#Scheffers|Scheffers (1899)]]. Furthermore, setting <math>v=\tfrac{2a}{1+a^{2}}=\tfrac{k^{2}-1}{k^{2}+1}</math> together with <math>\cos\alpha'=\tfrac{X'}{-R'}</math> and <math>\cos\alpha=\tfrac{X}{R}</math> gives: {{NumBlk|:|<math>\cos\alpha'=\frac{\cos\alpha-v}{1-v\cos\alpha}\quad\text{or}\quad\tan\frac{\alpha'}{2}=\sqrt{\frac{1+v}{1-v}}\tan\frac{\alpha}{2}</math>|{{equationRef|3}}}} Formula (3) was already used by [[#Darboux|Darboux (1873)]] as a sphere transformation, and in 1881 he showed that it can also be used to perform Laguerre transformations of planes. In special relativity, it turns out that formula (3) describes the aberration of light, see [[../Lorentz transformation (velocity)#Velocity addition and aberration|E:velocity addition and aberration]]. ==Historical notation== ==={{anchor|Bonnet}} Bonnet (1856) === [[w:Pierre Ossian Bonnet]] (1856) defined a reciprocal transformation preserving lines of curvatures. He noted that his transformation implies the following relation between curvature radii <math>\rho,\rho_{1}</math> and ordinates <math>\zeta,\zeta_{1}</math> of the respective curvature centers:<ref group=M>Bonnet (1856), p. 487</ref> :<math>\rho_{1}=i\zeta,\quad\rho=-i\zeta_{1}</math> where <math>i=\sqrt{-1}</math> <p style="background-color:Beige;border:1px solid black">Bonnet's transformation produces <math>\rho^{2}-\zeta^{2}=\rho_{1}^{2}-\zeta_{1}^{2}</math> and represents a special case of Laguerre inversion (or Lorentz transformation) ({{equationNote|1}}, {{equationNote|2}}) with <math>a=k=\sqrt{-1}</math>. [[#Lie|Lie (1871)]], [[#Darboux|Darboux (1887)]] and [[#Smith|Smith (1900)]] all noticed that Bonnet's transformation is a special case of Lie's and Laguerre's transformations.</p> ==={{anchor|Ribaucour}} Ribaucour (1870) === [[w:Albert Ribaucour]] (1870),<ref group=M>Ribaucour (1870). pp. 330-333</ref> defined what was later called “Ribaucour transformations” preserving lines of curvature: :p. 330: If circles are normal to three surfaces, they are normal to a family of surfaces belonging to a triply orthogonal system. This results in a class of orthogonal triple systems which I will propose to call cyclic systems, intimately linked to the deformation of surfaces. Given a surface (A), we can propose to seek all the cyclic systems which derive from it; the <math>ds^{2}</math> of this surface being put in the form <math>ds^{2}=\lambda^{2}.dx\ dy</math> [...] :p. 332: If spheres have their contact chords normal to surfaces, the circles passing through the centers of these spheres and their points of contact with their enveloping surfaces are normal to an infinity of surfaces forming part of a cyclic system. [...] If surfaces are part of an orthogonal system, the osculating circles of their orthogonal trajectories corresponding to all the points of one of these surfaces are normal to a family of surfaces belonging to a cyclic system. [...] I will point out the simple case where (A) is a plane, a case which leads to a general transformation of the surfaces with correspondence of the lines of curvature [...]. <p style="background-color:Beige;border:1px solid black">Referring to p. 332 of Ribaucour's paper, [[#Darboux|Darboux (1887)]] and [[#Bateman|Bateman (1910)]] argued that Ribaucour anticipated both [[#Lie|Lie (1871)]] and [[#Laguerre|Laguerre (1880)]] in formulating the “transformation by reciprocal directions”, which in Darboux's representation led to algebraic expressions identical to Laguerre inversion (or Lorentz transformation) ({{equationNote|1}}) and ({{equationNote|3}}).</p> ==={{anchor|Lie}} Lie (1871)=== In several papers between 1847 and 1850 it was shown by [[w:Joseph Liouville]]<ref group=M>Liouville (1847)</ref> that the relation ''λ(δx²+δy²+δz²)'' is invariant under the group of [[w:conformal transformation]]s generated by [[w:Spherical wave transformation#Transformation by reciprocal radii|w:inversions]] transforming spheres into spheres, which can be related [[w:special conformal transformation]]s or [[w:Möbius transformation]]s. (The conformal nature of the linear fractional transformation <math>\tfrac{a+bz}{c+dz}</math> of a complex variable <math>z</math> was already discussed by Euler (1777)).<ref group=M>Euler (1777), p. 140</ref><ref name=kastrup>Kastrup (2008), section 2.1</ref> Liouville's theorem was extended to all dimensions by [[w:Sophus Lie]] (1871a).<ref group=M name=lie1>Lie (1871), pp. 199–209</ref><ref>Kastrup (2008), section 2.3</ref> In addition, Lie described a manifold whose elements can be represented by spheres, where the last coordinate ''y_n+1'' can be related to an imaginary radius by ''iy_n+1'':<ref group=M name=lie1 /> :<math>\begin{matrix}\sum_{i=1}^{i=n} (x_i-y_i)^2+y_{n+1}^2=0 \\ \downarrow\\ \sum_{i=1}^{i=n+1} (y_i^{\prime}-y_i^{\prime\prime})^2=0 \end{matrix}</math> If the second equation is satisfied, two spheres ''y′'' and ''y″'' are in contact. Lie then defined the correspondence between [[w:Contact geometry|w:contact transformations]] in ''R_n'' and conformal point transformations in ''R_n+1'': The sphere of space ''R_n'' consists of ''n+1'' parameter (coordinates plus imaginary radius), so if this sphere is taken as the element of space ''R_n'', it follows that ''R_n'' now corresponds to ''R_n+1''. Therefore, any transformation (to which he counted [[../Lorentz transformation (imaginary)#Lorentz transformation via orthogonal transformation|E:orthogonal transformations]] and inversions) leaving invariant the condition of contact between spheres in ''R_n'', corresponds to the conformal transformation of points in ''R_n+1''. He pointed out that conformal point transformations consist of motions (such as [[w:rigid transformation]]s and orthogonal transformations), similarity transformations, and inversions.<ref group=M>Lie (1871/72), first footnote on p. 186</ref> <p style="background-color:Beige;border:1px solid black">As shown by [[#Bateman|Bateman and Cunningham (1909)]], the spacetime conformal group Con(1,3) of "[[w:spherical wave transformation]]s" corresponds to the transformations of Lie's sphere geometry in which the radius indicates the fourth coordinate, while the Lorentz group SO(1,3) is a subgroup of Con(1,3). It's also known that the Möbius group and Laguerre group, which are both isomorphic to the Lorentz group, are subgroups of Lie's sphere transformations group.</p> In the same paper, Lie also mentioned the “well known fact” that “parallel transformations” (dilatations having the property of transforming planes to parallel planes) preserve lines of curvature, and he alluded to [[#Bonnet|Bonnet's (1856)]] transformation as an example.<ref group=M>Lie (1871/72), p. 184</ref> Generally, all of the discussed transformations that preserve lines of curvature are either inversions or parallel transformations.<ref group=M>Lie (1871/72), p. 186</ref> In a footnote he specifically remarked that line transformations under which "(const=0)" remains unchanged, give all transformations of ''R'' by which surfaces of common spherical image pass into other such surfaces, and that the new spherical image emerges from the former by a conformal point transformation of the image-sphere, and that [[#Bonnet|Bonnet's (1856)]] transformation belongs here.<ref group=M>Lie (1871/72), second footnote on p. 186</ref> <p style="background-color:Beige;border:1px solid black">Lie himself (1884)<ref group=M>Lie (1884), footnote on p. 541</ref> pointed out that his remarks indicate the same transformation group treated in more recent works of [[#Laguerre|Laguerre (1880-82)]] and [[#Stephanos|Stephanos (1882)]]. Consequently, [[#Smith|Smith (1900)]] credits Lie as being the first one to allude to the existence of the (extended) Laguerre group, transforming spheres into spheres and planes into planes. On the other hand, [[#Darboux|Darboux (1887)]] pointed out that the transformation by reciprocal directions was already anticipated by [[#Ribaucour|Ribaucour (1870)]] even before Lie.</p> ==={{anchor|Klein3}} Klein, Pockels, Bôcher (1871-91)=== In relation to line geometry, [[w:Felix Klein]] (1871/72)<ref group=M>Klein (1871/72), p. 268</ref> used coordinates satisfying the condition <math>s_{1}^{2}+s_{2}^{2}+s_{2}^{2}+s_{2}^{2}+s_{5}^{2}=0</math>. They were introduced in 1868 (belatedly published in 1873) by [[w:Gaston Darboux]]<ref group=M>Darboux (1873), p. 137</ref> as a system of five coordinates in ''R₃'' (later called "pentaspherical" coordinates) in which the last coordinate is imaginary. [[w:Sophus Lie]] (1871)<ref group=M>Lie (1871), p. 208</ref> more generally used ''n+2'' coordinates in ''R_n'' (later called "polyspherical" coordinates) satisfying <math>\scriptstyle \sum_{i=1}^{i=n+2}x_{i}^{2}=0</math> in which the last coordinate is imaginary, as a means to discuss conformal transformations generated by inversions. These simultaneous publications can be explained by the fact that Darboux, Lie, and Klein corresponded with each other by letter. When the last coordinate is defined as real, the corresponding polyspherical coordinates satisfy the form of a sphere. Initiated by lectures of Klein between 1889–1890, his student [[w:Friedrich Carl Alwin Pockels]] (1891) used such real coordinates, emphasizing that all of these coordinate systems remain invariant under conformal transformations generated by inversions:<ref group=M>Pockels (1891), pp. 197–206</ref> :<math>x_1^2+x_2^2+\cdots+x_{n+1}^2-x_{n+2}^2=0 \text{ or } \sum_1^{n+1} x_h^2-x_{n+2}^2=0</math> Special cases were described by Klein (1893):<ref group=M>Klein (1893c), pp. 200ff (pentaspherical), pp. 373ff (tetracyclical)</ref> :<math>y_1^2+y_2^2+y_3^2+y_4^2-y_5^2=0</math> (pentaspherical). :<math>x_1^2+x_2^2+x_3^2-x_4^2=0</math> (tetracyclical). Both systems were also described by [[w:Maxime Bôcher]] (1894) in an expanded version of a thesis supervised by Klein.<ref group=M>Bôcher (1894), pp. 30–34, 40–43</ref> <p style="background-color:Beige;border:1px solid black">Polyspherical coordinates indicate that the conformal group {{nowrap|Con(0,p)}} is isomorphic to the Lorentz group SO(1,p+1).<ref>Kastrup (2008), p. 22</ref> For instance, Con(0,2) – known as Möbius group – is related to tetracyclical coordinates satisfying <math>x_{1}^{2}+x_{2}^{2}+x_{3}^{2}-x_{4}^{2}=0</math>, which is nothing other than the Lorentz interval invariant under the Lorentz group SO(1,3).</p> ==={{anchor|Darboux}} Darboux (1873-87)=== In 1873, [[w:Gaston Darboux]] stated the following proposition:<ref group=M>Darboux (1873), pp. 254-255.</ref> :Given a surface <math>\left(\Sigma\right)</math>, we add a fixed sphere <math>\left({\rm S}\right)</math> to it, and we construct all spheres tangent to the surface and intersecting <math>\left({\rm S}\right)</math> at a constant angle <math>\alpha</math>. Through the intersection of each of these spheres and <math>\left({\rm S}\right)</math> new spheres pass intersecting <math>\left({\rm S}\right)</math> at a constant angle <math>\beta</math>. These new spheres envelop a surface <math>\left(\Sigma_{1}\right)</math>, corresponding point by point to <math>\left(\Sigma\right)</math> with conservation of lines of curvature. The corresponding points on the two surfaces are on circles normal both to the two surfaces and to the sphere <math>\left({\rm S}\right)</math>. which he generalized by making a second proposition:<ref group=M>Darboux (1873), footnote on p. 255.</ref> :Consider a surface <math>\left(\Sigma\right)</math>, envelope of a series of variable spheres <math>\left(\rm U\right)</math> intersecting under any angles the sphere <math>\left(\rm S\right)</math>. At each of the spheres <math>\left(\rm U\right)</math> intersecting <math>\left(\rm S\right)</math> at an angle I call <math>\varphi</math> we match a sphere <math>\left(\rm U_1\right)</math> passing through the intersection of <math>\left(\rm S\right)</math> and from <math>\left(\rm U \right)</math>, and intersecting <math>\left(\rm S\right)</math> at an angle <math>\varphi_1</math> determined by equation ::<math>\frac{\cos\varphi-\cos\varphi_{1}}{1-\cos\varphi\cos\varphi_{1}}=h</math> :Then the new spheres <math>\left(\rm U_1\right)</math> envelop a surface <math>\left(\Sigma_1\right)</math> which corresponds point by point at <math>\left(\Sigma\right)</math> with curvature lines preserved. If we subject the spheres <math>\left(\rm U\right)</math> tangent to <math>\left(\Sigma \right)</math> to cut <math>\left(\rm S\right)</math> under a constant angle, <math>\varphi</math> will be constant; it will be the same for <math>\varphi_1</math>, by virtue of the previous equation, and we find the theorem given above. » <p style="background-color:Beige;border:1px solid black">This is equivalent to Laguerre transformation (or Lorentz transformation) ({{equationNote|3}}) with <math>h=\beta</math>.</p> In 1881 he quoted his above propositions, gave priority to the first one to [[#Ribaucour|Ribaucour (1870)]], and then showed that Laguerre's transformation of reciprocal directions is included as well:<ref group=M>Darboux (1881), p. 286f.</ref> :This proposal gave a new means of realizing a mode of transformation of surfaces with preservation of the lines of curvature, to which [[#Ribaucour|Ribaucour]] had devoted a few lines in a Communication made to the Academy in 1870 ''sur la deformation des surfaces''. :[..] Suppose, in particular, that the sphere <math>\left(\rm S\right)</math> reduces to a plane <math>\left(\pi\right)</math>. Then to any plane <math>\left(\rm P\right)</math> will correspond a plane <math>\left(\rm P'\right)</math> passing through the intersection of <math>\left(\pi\right)</math> and <math>\left(\rm P\right)</math>, and the angles <math>\varphi,\varphi'</math> that the planes <math>\left(\rm P\right)</math>, <math>\left(\rm P'\right)</math> make with <math>\left(\pi\right)</math> will be linked by relation (1). It is not difficult to recognize, in this transformation from one plane to another, that which has recently been studied by [[#Laguerre|Laguerre]] under the name of ''transformation by reciprocal directions''. We see that it is included in the transformation of spheres which is defined by our second proposition. I have recalled these results only to arrive at the proposition which is the main object of this Communication. I will show, in accordance with a general theorem of [[#Lie|Lie]], that the transformation first proposed by [[#Ribaucour|Ribaucour]] boils down to dilatations (transition from a surface to the parallel surface) and to transformations by reciprocal vector rays. He went on to rewrite his 1873 equation as:<ref group=M>Darboux (1881), footnote on p. 287</ref> :<math>\mathrm{tang}\frac{\varphi}{2}=\mathrm{tang}\frac{\varphi_{1}}{2}\sqrt{\frac{1-h}{1 +h}}</math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Laguerre transformation (or Lorentz transformation) ({{equationNote|3}}) with <math>h=\beta</math>.</p> In 1887, Darboux gave a much more detailed account. For instance, he re-derived and extended the transformation of oriented half-lines given by [[#Laguerre|Laguerre (1882)]] using coordinates ''x,y,z,R'':<ref group=M>Darboux (1887), p. 254</ref> :<math>\begin{matrix}x^{\prime2}+y^{\prime2}+z^{\prime2}-R^{\prime2}=x^{2}+y^{2}+z^{2}-R^{2}\\ \hline \begin{align}x' & =x, & z' & =\frac{1+k^{2}}{1-k^{2}}z-\frac{2kR}{1-k^{2}},\\ y' & =y, & R' & =\frac{2kz}{1-k^{2}}-\frac{1+k^{2}}{1-k^{2}}R, \end{align} \end{matrix}</math> or <math>\begin{align}z'+R' & =\frac{1+k}{1-k}(z-R)\\ z'-R' & =\frac{1-k}{1+k}(z+R) \end{align}</math> He went on to derive expressions and theorems similar to those given by him in 1873, and added that [[#Bonnet|Bonnet's (1856)]] transformation is a special case.<ref group=M>Darboux (1887), p. 256</ref> <p style="background-color:Beige;border:1px solid black">This is equivalent to Laguerre inversion (or Lorentz transformation) ({{equationNote|1}}).</p> Regarding the history of such transformations (before Laguerre's research) he wrote:<ref group=M>Darboux (1887), footnote on p. 259</ref> :In the memoir already quoted, inserted in volume V of ''Mathematische Annalen'', [[#Lie|Lie]] has made known all the contact transformations which preserve the lines of curvature; he even pointed out (p. 186) the particular case of transformation by reciprocal directions; but this transformation had already been given in different works by [[#Ribaucour|Ribaucour]]. See, in particular, Ribaucour's note ''sur la deformation des surfaces (Comptes rendus, t. LXX, p. 332, 1870)''. In a different form, it was the subject of the author's studies published in Notes V and IX of ''Mémoire sur une classe remarquable de courbes et de surfaces algébriques'', 1873. ==={{anchor|Laguerre}} Laguerre (1880-82) === A systematic formulation of a geometry of orientation was given by [[w:Edmond Laguerre]] (1880), including geometric transformations of oriented planes into oriented planes and oriented spheres into oriented spheres, which he called "[[w:Spherical wave transformation#Transformation by reciprocal directions|w:transformation by reciprocal directions]]".<ref group=M>Laguerre (1880)</ref> Besides the focus on the transformation of planes, a distinguishing feature to previous authors was the employment of the concept of orientation (i.e. attributing a certain sign to lines and radii) which became an indispensable tool in Lie sphere geometry and Laguerre geometry. <p style="background-color:Beige;border:1px solid black">Laguerre's transformations form a group (Laguerre group) which is isomorphic to the Lorentz group, and forms a subgroup of [[#Lie|Lie's (1871)]] contact transformations of spheres.</p> In 1882 he developed the “transformation of oriented half-lines” which was later called "Laguerre inversion", using the following algebraic formulation (''R'' being the radius and ''D'' the distance of its center to the axis):<ref group=M>Laguerre (1882), pp. 550–551.</ref> :<math>\left.\begin{align}D' & =\frac{D\left(1+\alpha^{2}\right)-2\alpha R}{1-\alpha^{2}}\\ R' & =\frac{2\alpha D-R\left(1+\alpha^{2}\right)}{1-\alpha^{2}} \end{align} \right|\begin{align}D^{2}-D^{\prime2} & =R^{2}-R^{\prime2}\\ D-D' & =\alpha(R-R')\\ D+D' & =\frac{1}{\alpha}(R+R') \end{align} </math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Laguerre inversion (or Lorentz transformation) ({{equationNote|1}}). The Laguerre inversions are generators of the Laguerre group.</p> ==={{anchor|Stephanos}} Stephanos (1883)=== [[w:Cyparissos Stephanos]] (1883)<ref group=M>Stephanos (1883), p. 590ff</ref> showed that Hamilton's biquaternion ''a₀+a₁ι₁+a₂ι₂+a₃ι₃'' can be interpreted as an oriented sphere in terms of [[#Lie|Lie's sphere geometry (1871)]], having the vector ''a₁ι₁+a₂ι₂+a₃ι₃'' as its center and the scalar <math>a_{0}\sqrt{-1}</math> as its radius. Its norm <math>a_{1}^{2}+a_{2}^{2}+a_{3}^{2}+a_{4}^{2}</math> is thus equal to the power of a point of the corresponding sphere. In particular, the norm of two quaternions ''N(Q₁-Q₂)'' (the corresponding spheres are in contact with ''N(Q₁-Q₂)=0'') is equal to the tangential distance between two spheres. The general contact transformation between two spheres then can be given by a [[w:homography]] using 4 arbitrary quaternions ''A,B,C,D'' and two variable quaternions ''X,Y'':<ref group=M>Stephanos (1883), p. 592</ref><ref>Cartan & Study (1908), p. 460</ref><ref>Rothe (1916), p. 1399</ref> :<math>XAY+XB+CY+D=0</math> (or <math>X=-\frac{CY+D}{AY+B}</math>). Stephanos pointed out that the special case ''A=0'' denotes transformations of oriented planes (see [[#Laguerre|Laguerre (1882)]]). <p style="background-color:Beige;border:1px solid black">The Lorentz group {{nowrap|SO(1,3)}} is a subgroup of the conformal group {{nowrap|Con(1,3)}} in terms of [[#Lie|Lie's (1871)]] transformations of oriented spheres in which the radius indicates the fourth coordinate. The Lorentz group is isomorphic to the group of [[#Laguerre|Laguerre's (1880)]] transformation of oriented planes.</p> ==={{anchor|Scheffers}} Scheffers (1899)=== [[w:Georg Scheffers]] (1899) synthetically determined all ''finite'' [[w:contact transformation]]s preserving circles in the plane, consisting of dilatations, inversions, and the following one preserving circles and lines (compare with Laguerre inversion by [[#Laguerre|Laguerre (1882)]] and [[#Darboux|Darboux (1887)]]):<ref group=M>Scheffers (1899), p. 158</ref> :<math>\begin{matrix}\sigma^{\prime2}-\rho^{\prime2}=\sigma^{2}-\rho^{2}\\ \hline \rho'=\frac{\rho}{\cos\omega}+\sigma\tan\omega,\quad\sigma'=\rho\tan\omega+\frac{\sigma}{\cos\omega} \end{matrix}</math> <p style="background-color:Beige;border:1px solid black">This is equivalent to Laguerre transformation (or Lorentz transformation) ({{equationNote|1}}) by the identity <math>\sin\omega=\beta=\frac{2a}{1+a^{2}}=\frac{k^{2}-1}{k^{2}+1}</math>.</p> ==={{anchor|Smith}} Smith (1900)=== [[w:Percey F. Smith]] (1900) followed [[#Laguerre|Laguerre (1882)]] and [[#Darboux|Darboux (1887)]] and defined the Laguerre inversion as follows:<ref group=M>Smith (1900), p. 159</ref> :<math>\begin{matrix}p^{\prime2}-p^{2}=R^{\prime2}-R^{2}\\ \hline \kappa=\frac{R'-R}{p'-p}\\ p'=\frac{\kappa^{2}+1}{\kappa^{2}-1}p-\frac{2\kappa}{\kappa^{2}-1}R,\quad R'=\frac{2\kappa}{\kappa^{2}-1}p-\frac{\kappa^{2}+1}{\kappa^{2}-1}R \end{matrix}</math> He added that [[#Bonnet|Bonnet's (1856)]] transformation is a special case with <math>\kappa^{2}=-1</math>, and he also gave credit to [[#Lie|Lie (1871)]] for defining the corresponding "group of the geometry of reciprocal directions". <p style="background-color:Beige;border:1px solid black">This is equivalent to Laguerre inversion (or Lorentz transformation) ({{equationNote|2}}).</p> ==={{anchor|Bateman}} Bateman and Cunningham (1909–1910)=== In line with [[#Lie|Lie's (1871)]] research on the relation between sphere transformations with an imaginary radius coordinate and 4D conformal transformations, it was pointed out by [[w:Harry Bateman]] and [[w:Ebenezer Cunningham]] (1909–1910), that by setting ''u=ict'' as the imaginary fourth coordinates one can produce spacetime conformal transformations. Not only the quadratic form <math>\lambda\left(dx^{2}+dy^{2}+dz^{2}+du^{2}\right)</math>, but also [[w:Maxwells equations]] are covariant with respect to these transformations, irrespective of the choice of λ. These variants of conformal or Lie sphere transformations were called [[w:spherical wave transformation]]s by Bateman.<ref group=R>Bateman (1909/10), pp. 223ff</ref><ref group=R>Cunningham (1909/10), pp. 77ff</ref> However, this covariance is restricted to certain areas such as electrodynamics, whereas the totality of natural laws in inertial frames is covariant under the [[w:Lorentz group]].<ref group=R>Klein (1910)</ref> In particular, by setting λ=1 the Lorentz group {{nowrap|SO(1,3)}} can be seen as a 10-parameter subgroup of the 15-parameter spacetime conformal group {{nowrap|Con(1,3)}}. Bateman (1910/12)<ref>Bateman (1910/12), pp. 358–359</ref> also alluded to the identity between the [[#Laguerre|Laguerre inversion]] and the Lorentz transformations. In general, the isomorphism between the Laguerre group and the Lorentz group was pointed out by [[w:Élie Cartan]] (1912, 1915/55),<ref name="ReferenceA"/><ref group=R>Cartan (1912), p. 23</ref> [[w:Henri Poincaré]] (1912/21)<ref group=R>Poincaré (1912/21), p. 145</ref> and others. ==References== ===Historical mathematical sources=== {{reflist|3|group=M}} *{{#section:History of Topics in Special Relativity/mathsource|boch94pot}} *{{#section:History of Topics in Special Relativity/mathsource|bon56}} *{{#section:History of Topics in Special Relativity/mathsource|dar73}} *{{#section:History of Topics in Special Relativity/mathsource|dar81cou}} *{{#section:History of Topics in Special Relativity/mathsource|dar87cou}} *{{#section:History of Topics in Special Relativity/mathsource|eul77}} *{{#section:History of Topics in Special Relativity/mathsource|klei72a}} *{{#section:History of Topics in Special Relativity/mathsource|klei93c}} *{{#section:History of Topics in Special Relativity/mathsource|lagu80}} *{{#section:History of Topics in Special Relativity/mathsource|lagu82}} *{{#section:History of Topics in Special Relativity/mathsource|lie71a}} *{{#section:History of Topics in Special Relativity/mathsource|lie71b}} *{{#section:History of Topics in Special Relativity/mathsource|lie84}} *{{#section:History of Topics in Special Relativity/mathsource|liou50}} *{{#section:History of Topics in Special Relativity/mathsource|poc91}} *{{#section:History of Topics in Special Relativity/mathsource|rib70}} *{{#section:History of Topics in Special Relativity/mathsource|schef99}} *{{#section:History of Topics in Special Relativity/mathsource|smi00}} *{{#section:History of Topics in Special Relativity/mathsource|ste83}} ===Historical relativity sources=== {{reflist|3|group=R}} {{#section:History of Topics in Special Relativity/relsource|bate10elec}} {{#section:History of Topics in Special Relativity/relsource|bate12}} {{#section:History of Topics in Special Relativity/relsource|car12}} {{#section:History of Topics in Special Relativity/relsource|cunn10}} {{#section:History of Topics in Special Relativity/relsource|klein10}} {{#section:History of Topics in Special Relativity/relsource|poi21}} ===Secondary sources=== {{reflist|3}} {{#section:History of Topics in Special Relativity/secsource|L5}} [[Category:Special Relativity]] [[Category:History of Physics]] eisurr81z7s57bd7j1equwgowhw9zv2 0 269441 2413988 2413895 2022-08-12T16:07:54Z Deryck Chan 319745 Let's say we don't create Q items for Andrew and Ellen now, format properly wikitext text/x-wiki <noinclude>{{WikiJ top menu}} __NOTOC__ '''Technical editors''' help in administrative tasks behind the scenes including processing articles, updating metadata, and formatting accepted manuscripts ([[WikiJournal User Group/Editorial guidelines/Technical editor summary|summary of tasks]]). If you are interested in joining as a technical editor, you can '''[https://en.wikiversity.org/w/index.php?title=Talk:{{PAGENAMEE}}&action=edit&section=new&preload={{ROOTPAGENAMEE}}%2FTechnical_editors%2FApplication&summary=Technical+editor+application apply here]'''. All previous applications can be [[Talk:WikiJournal User Group/Technical editors|viewed here]]. {{wjh_h2|Technical editors}} </noinclude>{{div col|colwidth=35em}} <!--Please keep alphabetical order by last name--> {{editor info | Q = Q112583961}}<!--Peter Agan--> {{editor info | Q = Q112583921}}<!--Crystal Au--> {{editor info | Q = Q112583956}}<!--Natalie Charamut--> {{editor info | Q = Q112583931}}<!--Emma Chiu--> {{editor info | Q = Q112583948}}<!--Michelle Fong--> {{editor info | Q = Q104653325}}<!--Jenna Harmon--> {{editor info | Q = Q103815757}}<!--Joshua Langfus--> {{editor info | Q = Q104653176}}<!--Cody Naccarato--> {{editor info | Q = Q99676847}}<!--Logan Smith--> {{editor info | Q = Q112583969}}<!--Stephnie Watson--> {{editor info | Q = Q112583943}}<!--Iris Yang--> {{editor info | name = Andrew Neil}} {{editor info | name = Ellen Sussman}} {{div col end}}<noinclude> {{wjs_h2|Previous technical editors}} {{editor info | Q = Q99677089}}<!--Emma Grace Choplin--> {{editor info | Q = Q104653784}}<!--Wilson Jacobs--> {{editor info | Q = Q78170633}}<!--Mohammed Sadat Abdulai--> {{wjs_h2|Role details}} ===Main tasks=== The tasks of technical editors are essentially technical and largely repetitive tasks relating to the preparation, peer review and publishing of articles. This allows authors, peer reviewers, board members and other contributors (who are all non-paid volunteers) to focus on their tasks. Such tasks include: *Editing submitted articles to WikiJournal: **Copyediting articles (including image formatting, reference formatting, and checking image attributions) **Managing journal metadata (including articles, authors, reviewers, and editors) **Preparing and uploading the pdf version of articles **Generating DOI codes (Digital Object Identifiers) for accepted articles *Assisting in [[WikiJournal_User_Group/Editorial_guidelines#Arranging_peer_review|arranging peer reviews]] of articles submitted to WikiJournal, by regularly checking the potential upcoming articles, and offer assistance to peer review coordinators at least in articles with delayed progression. Such assistance may be in organizing lists of names, credentials and emails of potential peer reviewers. *Keeping a record of tasks performed and how much time was used for each task, to be presented monthly to the administrative board of WikiJournal. A more detailed description of technical editor tasks is located at: * [[WikiJournal User Group/Editorial guidelines/Technical editor summary|Task process summary]] * [[WikiJournal User Group/Technical editors/tasks|Current open tasks]] ===Additional tasks=== If having deeper technical experience, the technical editor could help out in tasks such as: *Creating a bot for adding metadata items to articles at Wikidata ([[wikidata:Q44275619|Example page]]) *Creating a bot for keeping the [[Template:Article info|''Article info'' template]] synchronized between main pages and subpages and adding accepted articles to the relevant issue page. *Be able to help out in developing items for the [[meta:WikiJournal/Technical_wishlist|technical wishlist of WikiJournal]] The ''techincal editor'' should act in accordance with the policies of WikiJournal, as described in the [[WikiJournal User Group/Bylaws|Bylaws]] and [[WikiJournal User Group/Ethics statement|Ethics statement]] of WikiJournal. In case the ''techincal editor'' suspects [[WikiJournal_User_Group/Ethics_statement#Scientific_misconduct|scientific misconduct]] or undisclosed [[WikiJournal_User_Group/Ethics_statement#Disclosure_and_Conflict_of_Interest|conflicts of interest]], the ''techincal editor'' should inform the ''editor-in-chief'' or an ''editorial board member'' of the affected journal. {{wjs_h2|Admin details}} ===Budget=== The project received funding for hiring technical editors in the [[meta:Grants:Simple/Applications/WikiJournal User Group/2022|2022 grant]], amounting to $50,000. The rate was set to to $20 per hour as of [[meta:WikiJournal User Group/Meetings/2020-10-09|2020-10-09]]. ===Hiring process=== If or when the WikiJournal User Group will have an open position, the hiring process may consist of: *First looking among current board members and associate editors for appropriate candidates. *If this doesn't lead to choosing a technical editor, then it may be advertised externally. *Any candidate will be interviewed, wherein all WikiJournal participants may suggest questions. 2-3 people will volunteer to screen applicants, with summaries sent to all editorial boards. The technical editor will then be hired based on consensus among board members. That person will begin editing with a limited budget, and the result will be evaluated to make a decision of whether to proceed in the same manner. </noinclude> [[Category:WikiJournal User Group]] n477cdurl3ptd9qbl6ryiga1dy8mmr6 0 277657 2414003 2413898 2022-08-12T20:22:05Z JimmyOC1985 2925861 /* Emotion */ wikitext text/x-wiki {{/Banner}} ==Motivation == # [[Academic help-seeking]] - What are the barriers and enablers of AHS and how can AHS be fostered? - [[User:Ibm4444|Ibm4444]] # [[/Academic self-regulation/]] - What is academic self-regulation, why does it matter, and how can it be fostered? - [[U3216563]] # [[/Actively open-minded thinking/]] - How can AOT be used to improve human performance? - [[User:MyUserName|MyUserName]] # [[/Active transport motivation/]] - What motivates use of active transport and how can people be encouraged to use it? - [[User:MyUserName|MyUserName]] # [[/Antidepressants and motivation/]] - What are the effects of popular antidepressants on motivation? - [[User:U3222363|U3222363]] # [[/Approach motivation/]] - What is approach motivation and how does it lead to behaviour? - [[User:U3189370|U3189370]] # [[/Behavioural economics and motivation/]] - What aspects of motivation theory are useful in behavioural economics? - [[User:U3141987|U3141987]] # [[/Behavioural model of health services/]] - What is the BMHS and how can it be used? - SoSilverLibby # [[/Beneficence as a psychological need/]] - What is beneficence and what are its implications as a psychological need? - [[User:MyUserName|CaitlinEmc]] # [[/Brief motivational interviewing as a health intervention/]] - How can brief motivational interviewing be used as a health intervention? - [[User:MyUserName|MyUserName]] # [[/Choice overload/]] - What is choice overload? What is the optimal amount of choice? - [[UserGeorgiaFairweather|GeorgiaFairweather]] # [[/Chunking and goal pursuit/]] - How does chunking affect goal pursuit? - GiovanniBartlett # [[/Cognitive entrenchment/]] - What is cognitive entrenchment and how can it be avoided? - [[User:MyUserName|MyUserName]] # [[/Climate change helplessness/]] - How does learned helpless impact motivation to engage in behaviours to limit climate change? - [[User:U3193000|U3193000]] # [[/Closeness communication bias/]] - What is the CCB, why does it occur, and how can it be overcome? - [[User:U3215103|U3215103]] # [[/Commitment bias/]] - What motivates escalation of commitment even it does not lead to desirably outcomes? - [[User:MyUserName|MyUserName]] # [[/Conspiracy theory motivation/]] - What motivates people to believe in conspiracy theories? - [[User:KingMob221|KingMob221]] # [[/Construal level theory/]] - What is construal level theory and how can it be applied? - [[User:MyUserName|MyUserName]] # [[/Courage motivation/]] - What is courage, what motivates courage, and how can courage be enhanced? -[[User:Hanarose123|Hanarose123]] # [[/Death drive/]] - What is the death drive and how can it be negotiated? - [[User:U3086459|U3086459]] # [[Motivation and emotion/Book/2022/Drugs-violence nexus and motivation|Drugs-violence nexus and motivation]] - What is the role of motivation in the drugs-violence nexus? - [[Atu3202070|Atu3202070]] # [[/Episodic future thinking and delay discounting/]] - What is the relationship between between EFT and DD? - [[User:MyUserName|MyUserName]] # [[/Episodic memory and planning/]] - What role does episodic memory play in planning? - [[User:MyUserName|U3246310]] # [[/Equity theory/]] - What is equity theory and how can it be applied? - [[EKS2001|EKS2001]] # [[/ERG theory/]] - What is Alderfer's ERG theory? - [[User:MyUserName|MyUserName]] # [[/Frame of reference and motivation/]] - How does frame of reference affect motivation? - [[User:MyUserName|MyUserName]] # [[/Freedom and motivation/]] - What is the effect of freedom on motivation? - [[Cedevlin9|Cedevlin9]] # [[/Fully functioning person/]] - What is a FFP and how can full functioning be developed? - [[User:Sebastian Armstrong|Sebastian Armstrong]] # [[/Functional fixedness/]] - What is functional fixedness and how can it be overcome? - [[User:U3214117|U3214117]] # [[/Functional imagery training/]] - What is FIT and how can it be applied? - [[User:Btarmstrong24|Btarmstrong24]] # [[/Gamification and work motivation/]] - How can gamification enhance work motivation? - [[U3211125|U3211125]] # [[/Giving up goals/]] - When should we give up goals and when should we persist? - [[User:MyUserName|U3161584]] # [[/Green prescription motivation/]] - What motivates green prescription compliance? - [[User:Earthxangel|Earthxangel]] # [[/Health belief model/]] - What is the HBM and how can it be used to enhance motivation for health-promoting behaviour? - [[SoSilverLibby]] # [[/Help-seeking among boys/]] - What are the barriers to help-seeking for boys and what motivates them to seek help? - [[User:BradMcGrath|BradMcGrath]] # [[/Hidden costs of reward/]] - What are the hidden costs of motivating by reward? - [[User:SLoCE|u3033296]] # [[/Hijack hypothesis of drug addiction/]] - What is the hijack hypothesis, what is the evidence, and how does it help to understand drug addiction? - [[U3218292|U3218292]] # [[/Honesty motivation/]] - What motivates honesty? - [[User:U3200859|U3200859]] # [[/Humour, leadership, and work/]] - What role does humour play in effective leadership in the workplace? - [[User:U3210264|U3210264]] # [[/IKEA effect/]] - What is the IKEA effect and how can it be applied? - [[U3216963|U]]3216963 # [[/Intertemporal choice/]] - What are intertemporal choices and how can they be effectively negotiated? - [[User:MyUserName|MyUserName]] # [[/Kindness motivation/]] - What motivates kindness? - [[User:U3205429|U3205429]] # [[/Motivational music and exercise/]] - How can music be used to help motivate exercise? - [[User:MyUserName|U3183466]] # [[/Novelty-variety as a psychological need/]] - What is novelty-variety and what are its implications as a psychological need? - [[User:MyUserName|MyUserName]] # [[/Nucleus accumbens and motivation/]] - What role does the nucleus accumbens play in motivation? - [[User:U3213250|U3213250]] # [[/Perfectionism/]] - What motivates perfectionism? Is perfectionism good or bad? How can it be managed? - [[User:AEMOR|AEMOR]] # [[/Physiological needs/]] - How do human's physiological needs affect motivation? - [[U3203655]] # [[/Protection motivation theory and COVID-19/]] - How does PMT apply to managing COVID-19? - [[User:U3200956|U3200956]] # [[/Relative deprivation and motivation/]] - What is the effect of relative deprivation on motivation? - [[User:U3191574 (PHP)|U3191574 (PHP)]] # [[/Retrospective regret/]] - What is the motivational role of retrospective regret? - [[User:Will-U3214082|Will-U3214082]] # [[/Revenge motivation/]] - What motivates revenge and how does it affect us? - [[User:U3216654|U3216654]] # [[/Self-efficacy and academic achievement/]] - What role does self-efficacy play in academic achievement? - [[User:U943292|U943292]]a # [[/Self-efficacy and achievement/]] - What role does self-efficacy play in achievement outcomes? - [[User:U3216513mt|U3216513mt]] # [[/Sexual harassment at work motivation/]] - What motivates sexual harassment at work and what can be done about it? - [[User:U3037979|U3037979]] # [[/Signature strengths/]] - What are signature strengths and how can they be applied? - [[User:MyUserName|MyUserName]] # [[/Social cure/]] - What is the social cure and how can it be applied? - [[User:U3215976|U3215976]] # [[/System justification theory/]] - What is SJT, how does it affect our lives, and what can be done about it? - [[User:MyUserName|MyUserName]] # [[/Stretch goals/]] - What are stretch goals? Do they work? - [[User:MyUserName|MyUserName]] # [[/Sublimation/]] - What is sublimation and how can it be fostered? - [[User:MyUserName|MyUserName]] # [[/Survival needs and motivation/]] - What are survival needs and how do they influence motivation? - [[User:U3148161|U3148161]] # [[/Task initiation/]] - What are the challenges with task initiation and how to get get started? - [[User:MyUserName|U3210006]] # [[/Theoretical domains framework/]] - What is the TDF and how can be used to guide behaviour change? - [[User:MyUserName|MyUserName]] # [[/Time and motivation/]] - What is the effect of time on motivation? - [[User:Lturner2311|Lturner2311]] # [[/Time management/]] - How can one's time be managed effectively? - [[User:CNK.20|CNK.20]] # [[/To-do lists/]] - Are to-do lists a good idea? What are their pros and cons? How can they be used effectively? - [[User:U3207458|U3207458]] # [[/Uncertainty avoidance/]] - What is uncertainty avoidance, why does it occur, and what are its consequences? - [[User:Franklin Brightt|Franklin Brightt]] # [[/Urgency bias and productivity/]] - What is the impact of urgency bias on productivity and what can be done about it? - U3055143 # [[/Vocational identity/]] - What is vocational identity and how does it develop? - [[User:MyUserName|MyUserName]] # [[/Volunteer tourism motivation/]] - What motivates volunteer tourism? - [[User:U962051|U962051]] # [[/Wanting and liking/]] - What are the similarities and differences between wanting and liking, and what are the implications? - [[U3201643]] # [[/Work breaks, well-being, and productivity/]] - How do work breaks affect well-being and productivity? - [[User:MyUserName|U3215603]] # [[/Work and flow/]] - What characteristics of work can produce flow and how can flow at work be fostered? - [[User:U3213441|U3213441]] ==Emotion== # [[/Animal emotion/]] - What is the emotional experience of animals? - [[U3216502]] # [[/Attributions and emotion/]] - How do attributions affect emotion? - [[User:MyUserName|MyUserName]] # [[/Autonomous sensory meridian response and emotion/]] - What emotions are involved in ASMR experiences and why do they occur? - [[User:U3186959|U3186959]] # [[/Benzodiazepines and emotion/]] - What are the effects of benzodiazepines on emotion? - [[User:FulaAjeo22|FulaAjeo22]] # [[/Bewilderment/]] - What is bewilderment and how can it be dealt with? - SunandaUC # [[/Burnout/]] - What is burnout and how can be it be managed and prevented? - [[U3202788]] # [[/Cognitive dissonance reduction/]] - What strategies do people use to reduce cognitive dissonance and how effective are they? - [[User:Tatjurate|Tatjurate]] # [[/Colonisation and emotion in Australia/]] - What are the emotional responses to colonisation in Australia? - [[User:Micabaker1|Micabaker1]] # [[/Compassion/]] - What is compassion, what are its pros and cons, and how can it be fostered? - u3203545 # [[/Connection to country and well-being/]] - What is the relationship between connection to country and well-being? - [[User:MyUserName|MyUserName]] # [[/Contempt/]] - What is contempt, what causes it, and how can it be managed? - [[User:MyUserName|u3219905]] # [[/Core emotions/]] - What are the core emotions and what is their function? U3203140 # [[/Creative arts and trauma/]] - How can creative arts help in dealing with trauma? - [[MyUserName|SashaBrooksby]] # [[/Cultural influences on shame, guilt, and pride/]] - How does culture influence shame, guilt, and pride? - [[User:Tamika Afeaki|Tamika Afeaki]] # [[/Default mode network and the self/]] - What is the relationship between the DMN and the self? - [[User:MyUserName|MyUserName]] # [[/Difficult conversations and emotion/]] - What communication and emotional skills are needed to successfully negotiate difficult conversations? - [[User:u3158968|u3158968]] # [[/Disappointment/]] - What is disappointment, what causes disappointment, and how can disappointment be managed? - [[User:U3216256|U3216256]] # [[/DMT and spirituality/]] - How can DMT facilitate spiritual experiences? - [[DenniseSoleymani]] # [[/Durability bias in affective forecasting/]] - What role does durability bias play in affective forecasting? - [[User:MyUserName|MyUserName]] # [[/Ecological grief/]] - What is ecological grief and what can be done about it? - [[User:Brewerjr|Brewerjr]] # [[/Ecopsychology and stress/]] - How can ecopsychology help to explain and deal with stress? - [[User:MyUserName|MyUserName]] # [[/Embarrassment/]] - What is embarrassment, what causes it, and how can it be managed? - u3190353 # [[/Emotional intelligence training/]] - How can emotional intelligence be trained? - Eimilerous22 # [[/Emotion knowledge/]] - What is emotion knowledge and how can it be developed? - [[User:GabbieUC|GabbieUC]] # [[/Emotion across the lifespan/]] - How does emotion develop across the lifespan? - u3230861 # [[/Endocannabinoid system and emotion/]] - What is the role of the endocannabinoid system in emotion? - [[User:RWilliams12|Rwilliams12]] # [[/Environmental grief/]] - What is eco-grief, its causes and consequences, and what can be done? - [[User:Gabrielle Eagling|Gabrielle Eagling]] # [[/Exercise and endocannabinoids/]] - What is the relationship between exercise and the endocannabinoid system? - [[User:MyUserName|MyUserName]] # [[/Expressive suppression and emotion regulation/]] - What is the role of expressive suppression in emotion regulation? - [[U3131472]] # [[/Fairness and emotion/]] - What is the relation between fairness and emotion? - U3246554 # [[/Fatigue and emotion/]] - What is the effect of fatigue on emotion and what can be done about it? - [[User:Lewis.Kusk|Lewis.Kusk]] # [[/Fear/]] - What is fear, what causes it, and how can it be managed? - [[User:Icantchooseone|Icantchooseone]] # [[/Fear of working out/]] - What is FOWO and how can it be overcome? - [[User:MyUserName|MyUserName]] # [[/Fundamental attribution error and emotion/]] - What is the relationship between the FAE and emotion? - [[User:MyUserName|MyUserName]] # [[/Gratitude and subjective wellbeing/]] - What is the relationship between gratitude and subjective wellbeing? - [[User:MyUserName|MyUserName]] # [[/Gloatrage/]] - What is gloatrage, what causes it, and what are its consequences? - [[User:MyUserName|MyUserName]] # [[/Heart rate variability and emotion regulation/]] - What is the relationship between HRV and emotion regulation? - [[User:MyUserName|MyUserName]] # [[/Hedonic adaptation prevention model/]] - What is the HAP model and how can it be applied? - [[User:Lyndel Lemon|Lyndel Lemon]] # [[/Humility/]] - What is humility, what causes it, and is it desirable? - [[User:MyUserName|MyUserName]] # [[/Hypomania and emotion/]] - What are the emotional characteristics of hypomania? - [[User:Alec.cortez|Alec.cortez]] # [[/Impact bias/]] - What is impact bias, what causes it, what are its consequences, and how can it be avoided? - [[User:MyUserName|MyUserName]] # [[Indigenous Australian emotionality]] - In what ways is emotionality experienced by Indigenous Australian people? - [[User:U3189442 - K.Ryan|U3189442 - K.Ryan]] # [[/Indigenous Australian mindfulness/]] - How has Indigenous Australian culture traditionally conceived of, and practiced, mindfulness? - [[User:MyUserName|MyUserName]] # [[/Inspiration/]] - What is inspiration, what causes it, what are its consequences, and how can it be fostered? - [[User:MyUserName|u3227354]] # [[/Insular cortex and emotion/]] - What role does the insular cortex play in emotion? - [[User:U3190094|U3190094]] # [[/Interoception and emotion/]] - What is the relationship between interoception and emotion? - u3203265 # [[/Kama muta/]] - What is kama muta, what are its effects, and how can it be fostered? - [[User:U3183521|U3183521]] # [[/Linguistic relativism and emotion/]] - What is the role of linguistic relativism in emotion? - [[User:U3119310|U3119310]] # [[/Menstrual cycle mood disorders/]] - What causes menstrual cycle mood disorders and how can they be managed? - [[User:MyUserName|U3217109]] # [[/Mindfulness and creativity/]] - How can mindfulness enhance creativity? - [[CaityDcr1603]] # [[/Mindful self-care/]] - What is mindful self-care, why does it matter, and how can it be developed? - [[User:clairelogan|clairelogan]] # [[/Mixed emotions/]] - What are mixed emotions, what causes them, and how can they be managed? - [[User:MyUserName|u3210490]] # [[/Mudita/]] - What is mudita and how can it be developed? - [[User:MyUserName|MyUserName]] # [[/Natural disasters and emotion/]] - How do people respond emotionally to natural disasters and how can they be supported? -[[User:U3148366_Chris|U3148366_Chris]] # [[/Nature therapy/]] - What is nature therapy and how can it be applied? - Ana028 # [[/Narcissism and emotion/]] - What is the relationship between narcissism and emotion? - [[User:A Super Villain|A Super Villain]] # [[/Narrative therapy and emotion/]] - What is the role of emotion in narrative therapy? - [[User:MyUserName|MyUserName]] # [[/Needle fear/]] - How does needle fear develop, what are its consequences, and what can be done about it? - [[User:U3166273|U3166273]] # [[/Positivity ratio/]] - What is the positivity ratio and what are its implications? - [[User:MyUserName|MyUserName]] # [[/Post-traumatic stress disorder and emotion/]] - What is the effect of PTSD on emotion? - [[User:JorjaFive|JorjaFive]] # [[/Psychological distress/]] - What is PD, what are the main types, and how can they be managed? - [[User:U3190773|U3190773]] # [[/Psychological trauma/]] - What causes psychological trauma, what are the consequences, and how can people recover from psychological trauma? - [[User:U3210431|U3210431]] # [[/Psilocybin assisted psychotherapy/]] - How can psilocybin be used to assist psychotherapy? - [[User:U3083720|U3083720]] # [[/Rational compassion/]] - What is rational compassion and how can it be cultivated? - [[User:MyUserName|MyUserName]] # [[/Reflected glory/]] - What is reflected glory and what are its pros and cons? - [[User:MyUserName|MyUserName]] # [[/Religiosity and coping/]] - What is the relationship between religiosity and coping? - [[U3215326]] # [[/Resentment/]] - What is resentment, what causes it, and what are its consequences? - [[User:U3216389|U3216389]] # [[/Risk-as-feelings/]] - What is the emotional experience of risk and how does it influence decision-making and behaviour? - BenjiD'Ange # [[/Self-esteem and culture/]] - What are the cultural influences on self-esteem? - [[User:Jingru shao 0906|Jingru shao0906]] # [[/Smiling and emotion/]] - What is the relationship between smiling and emotion? - U3200902 # [[/Social media and suicide prevention/]] - How can social media be used to help prevent suicide? - [[JaimeTegan|JaimeTegan]] # [[/Sorry business/]] - What is sorry business and what role does it play in Indigenous communities in Australia? - Isaacem13 # [[/Stress control mindset/]] - What is a SCM, why does it matter, and how can it be cultivated? - [[JimmyOC1985|JimmyOC1985]] # [[/Suffering as emotion/]] - What is the emotional experience of suffering and how can people cope with suffering? - [[User:Brookewin|Brookewin]] # [[/Telemental health/]] - What are the pros and cons of TMH and what are the key ingredients for effective TMH practices? - [[User:MyUserName|MyUserName]] # [[/Topophilia/]] - What is topophilia, how does it develop, and what are the psychological impacts? - [[User:RSPMeredith|RSPMeredith]] # [[/Triumph/]] - What is triumph, what causes it, and how can it be managed? - [[User:Bill.miosge|Bill.miosge]] # [[/Unemployment and mental health/]]: What is the relationship between unemployment and mental health? - [[User:MyUserName|U3216958 - Tiarna.Wilson-Ginn]] # [[/Viewing natural scenes and emotion/]] - What is the effect of viewing natural scenes on emotion and how can this be applied? - [[User:MyUserName|MyUserName]] # [[/Wave metaphor for emotion/]] - In what respects is an ocean wave a helpful metaphor for understanding human emotions? - [[jamieepiper]] # [[/Window of tolerance/]] - What is the window of tolerance and how this concept be used? - [[User:U3223109|U3223109]] # [[/Workplace mental health training/]] - What is WMHT, what techniques are used, and what are the impacts? - [[ArtOfHappiness]] # [[/Zoom fatigue/]] - What is Zoom fatigue, what causes it, what are its consequences, and what can be done about it? - [[User:u3211603|U3211603]] ==Motivation and emotion== # [[/Financial investing, motivation, and emotion/]] - What role does motivation and emotion play in financial investing? - [[U3217287|U3217287]] # [[/Hostage negotiation, motivation, and emotion/]] - What role does motivation and emotion play in hostage negotiation? - [[User:U3213549|U3213549]] # [[/Money priming, motivation, and emotion/]] - What is the effect of money priming on motivation and emotion? - [[User:Molzaroid|Molzaroid]] # [[/Motivational dimensional model of affect/]] - What is the motivational dimensional model of affect and what are its implications? - [[User:MyUserName|MyUserName]] # [[/Napping, motivation, and emotion/]] - What are the motivational and emotional effects of napping? - [[User:MyUserName|MyUserName]] # [[/Overchoice, emotion, and motivation/]] - What are the emotional and motivational effects of overchoice? - [[User:MyUserName|MyUserName]] # [[/Patience and impatience/]] - What are the psychological causes and consequences of patience and impatience? - [[User:u3100193|u3100193]] # [[/Reward system, motivation, and emotion/]] - What role does the reward system play in motivation and emotion? - [[User:U3162201|U3162201]] [[Category:Motivation and emotion/Book/2022]] 297i8fztfemx9f5ioc91ceo98s10ngh 2414004 2414003 2022-08-12T20:49:07Z JimmyOC1985 2925861 /* Emotion */ wikitext text/x-wiki {{/Banner}} ==Motivation == # [[Academic help-seeking]] - What are the barriers and enablers of AHS and how can AHS be fostered? - [[User:Ibm4444|Ibm4444]] # [[/Academic self-regulation/]] - What is academic self-regulation, why does it matter, and how can it be fostered? - [[U3216563]] # [[/Actively open-minded thinking/]] - How can AOT be used to improve human performance? - [[User:MyUserName|MyUserName]] # [[/Active transport motivation/]] - What motivates use of active transport and how can people be encouraged to use it? - [[User:MyUserName|MyUserName]] # [[/Antidepressants and motivation/]] - What are the effects of popular antidepressants on motivation? - [[User:U3222363|U3222363]] # [[/Approach motivation/]] - What is approach motivation and how does it lead to behaviour? - [[User:U3189370|U3189370]] # [[/Behavioural economics and motivation/]] - What aspects of motivation theory are useful in behavioural economics? - [[User:U3141987|U3141987]] # [[/Behavioural model of health services/]] - What is the BMHS and how can it be used? - SoSilverLibby # [[/Beneficence as a psychological need/]] - What is beneficence and what are its implications as a psychological need? - [[User:MyUserName|CaitlinEmc]] # [[/Brief motivational interviewing as a health intervention/]] - How can brief motivational interviewing be used as a health intervention? - [[User:MyUserName|MyUserName]] # [[/Choice overload/]] - What is choice overload? What is the optimal amount of choice? - [[UserGeorgiaFairweather|GeorgiaFairweather]] # [[/Chunking and goal pursuit/]] - How does chunking affect goal pursuit? - GiovanniBartlett # [[/Cognitive entrenchment/]] - What is cognitive entrenchment and how can it be avoided? - [[User:MyUserName|MyUserName]] # [[/Climate change helplessness/]] - How does learned helpless impact motivation to engage in behaviours to limit climate change? - [[User:U3193000|U3193000]] # [[/Closeness communication bias/]] - What is the CCB, why does it occur, and how can it be overcome? - [[User:U3215103|U3215103]] # [[/Commitment bias/]] - What motivates escalation of commitment even it does not lead to desirably outcomes? - [[User:MyUserName|MyUserName]] # [[/Conspiracy theory motivation/]] - What motivates people to believe in conspiracy theories? - [[User:KingMob221|KingMob221]] # [[/Construal level theory/]] - What is construal level theory and how can it be applied? - [[User:MyUserName|MyUserName]] # [[/Courage motivation/]] - What is courage, what motivates courage, and how can courage be enhanced? -[[User:Hanarose123|Hanarose123]] # [[/Death drive/]] - What is the death drive and how can it be negotiated? - [[User:U3086459|U3086459]] # [[Motivation and emotion/Book/2022/Drugs-violence nexus and motivation|Drugs-violence nexus and motivation]] - What is the role of motivation in the drugs-violence nexus? - [[Atu3202070|Atu3202070]] # [[/Episodic future thinking and delay discounting/]] - What is the relationship between between EFT and DD? - [[User:MyUserName|MyUserName]] # [[/Episodic memory and planning/]] - What role does episodic memory play in planning? - [[User:MyUserName|U3246310]] # [[/Equity theory/]] - What is equity theory and how can it be applied? - [[EKS2001|EKS2001]] # [[/ERG theory/]] - What is Alderfer's ERG theory? - [[User:MyUserName|MyUserName]] # [[/Frame of reference and motivation/]] - How does frame of reference affect motivation? - [[User:MyUserName|MyUserName]] # [[/Freedom and motivation/]] - What is the effect of freedom on motivation? - [[Cedevlin9|Cedevlin9]] # [[/Fully functioning person/]] - What is a FFP and how can full functioning be developed? - [[User:Sebastian Armstrong|Sebastian Armstrong]] # [[/Functional fixedness/]] - What is functional fixedness and how can it be overcome? - [[User:U3214117|U3214117]] # [[/Functional imagery training/]] - What is FIT and how can it be applied? - [[User:Btarmstrong24|Btarmstrong24]] # [[/Gamification and work motivation/]] - How can gamification enhance work motivation? - [[U3211125|U3211125]] # [[/Giving up goals/]] - When should we give up goals and when should we persist? - [[User:MyUserName|U3161584]] # [[/Green prescription motivation/]] - What motivates green prescription compliance? - [[User:Earthxangel|Earthxangel]] # [[/Health belief model/]] - What is the HBM and how can it be used to enhance motivation for health-promoting behaviour? - [[SoSilverLibby]] # [[/Help-seeking among boys/]] - What are the barriers to help-seeking for boys and what motivates them to seek help? - [[User:BradMcGrath|BradMcGrath]] # [[/Hidden costs of reward/]] - What are the hidden costs of motivating by reward? - [[User:SLoCE|u3033296]] # [[/Hijack hypothesis of drug addiction/]] - What is the hijack hypothesis, what is the evidence, and how does it help to understand drug addiction? - [[U3218292|U3218292]] # [[/Honesty motivation/]] - What motivates honesty? - [[User:U3200859|U3200859]] # [[/Humour, leadership, and work/]] - What role does humour play in effective leadership in the workplace? - [[User:U3210264|U3210264]] # [[/IKEA effect/]] - What is the IKEA effect and how can it be applied? - [[U3216963|U]]3216963 # [[/Intertemporal choice/]] - What are intertemporal choices and how can they be effectively negotiated? - [[User:MyUserName|MyUserName]] # [[/Kindness motivation/]] - What motivates kindness? - [[User:U3205429|U3205429]] # [[/Motivational music and exercise/]] - How can music be used to help motivate exercise? - [[User:MyUserName|U3183466]] # [[/Novelty-variety as a psychological need/]] - What is novelty-variety and what are its implications as a psychological need? - [[User:MyUserName|MyUserName]] # [[/Nucleus accumbens and motivation/]] - What role does the nucleus accumbens play in motivation? - [[User:U3213250|U3213250]] # [[/Perfectionism/]] - What motivates perfectionism? Is perfectionism good or bad? How can it be managed? - [[User:AEMOR|AEMOR]] # [[/Physiological needs/]] - How do human's physiological needs affect motivation? - [[U3203655]] # [[/Protection motivation theory and COVID-19/]] - How does PMT apply to managing COVID-19? - [[User:U3200956|U3200956]] # [[/Relative deprivation and motivation/]] - What is the effect of relative deprivation on motivation? - [[User:U3191574 (PHP)|U3191574 (PHP)]] # [[/Retrospective regret/]] - What is the motivational role of retrospective regret? - [[User:Will-U3214082|Will-U3214082]] # [[/Revenge motivation/]] - What motivates revenge and how does it affect us? - [[User:U3216654|U3216654]] # [[/Self-efficacy and academic achievement/]] - What role does self-efficacy play in academic achievement? - [[User:U943292|U943292]]a # [[/Self-efficacy and achievement/]] - What role does self-efficacy play in achievement outcomes? - [[User:U3216513mt|U3216513mt]] # [[/Sexual harassment at work motivation/]] - What motivates sexual harassment at work and what can be done about it? - [[User:U3037979|U3037979]] # [[/Signature strengths/]] - What are signature strengths and how can they be applied? - [[User:MyUserName|MyUserName]] # [[/Social cure/]] - What is the social cure and how can it be applied? - [[User:U3215976|U3215976]] # [[/System justification theory/]] - What is SJT, how does it affect our lives, and what can be done about it? - [[User:MyUserName|MyUserName]] # [[/Stretch goals/]] - What are stretch goals? Do they work? - [[User:MyUserName|MyUserName]] # [[/Sublimation/]] - What is sublimation and how can it be fostered? - [[User:MyUserName|MyUserName]] # [[/Survival needs and motivation/]] - What are survival needs and how do they influence motivation? - [[User:U3148161|U3148161]] # [[/Task initiation/]] - What are the challenges with task initiation and how to get get started? - [[User:MyUserName|U3210006]] # [[/Theoretical domains framework/]] - What is the TDF and how can be used to guide behaviour change? - [[User:MyUserName|MyUserName]] # [[/Time and motivation/]] - What is the effect of time on motivation? - [[User:Lturner2311|Lturner2311]] # [[/Time management/]] - How can one's time be managed effectively? - [[User:CNK.20|CNK.20]] # [[/To-do lists/]] - Are to-do lists a good idea? What are their pros and cons? How can they be used effectively? - [[User:U3207458|U3207458]] # [[/Uncertainty avoidance/]] - What is uncertainty avoidance, why does it occur, and what are its consequences? - [[User:Franklin Brightt|Franklin Brightt]] # [[/Urgency bias and productivity/]] - What is the impact of urgency bias on productivity and what can be done about it? - U3055143 # [[/Vocational identity/]] - What is vocational identity and how does it develop? - [[User:MyUserName|MyUserName]] # [[/Volunteer tourism motivation/]] - What motivates volunteer tourism? - [[User:U962051|U962051]] # [[/Wanting and liking/]] - What are the similarities and differences between wanting and liking, and what are the implications? - [[U3201643]] # [[/Work breaks, well-being, and productivity/]] - How do work breaks affect well-being and productivity? - [[User:MyUserName|U3215603]] # [[/Work and flow/]] - What characteristics of work can produce flow and how can flow at work be fostered? - [[User:U3213441|U3213441]] ==Emotion== # [[/Animal emotion/]] - What is the emotional experience of animals? - [[U3216502]] # [[/Attributions and emotion/]] - How do attributions affect emotion? - [[User:MyUserName|MyUserName]] # [[/Autonomous sensory meridian response and emotion/]] - What emotions are involved in ASMR experiences and why do they occur? - [[User:U3186959|U3186959]] # [[/Benzodiazepines and emotion/]] - What are the effects of benzodiazepines on emotion? - [[User:FulaAjeo22|FulaAjeo22]] # [[/Bewilderment/]] - What is bewilderment and how can it be dealt with? - SunandaUC # [[/Burnout/]] - What is burnout and how can be it be managed and prevented? - [[U3202788]] # [[/Cognitive dissonance reduction/]] - What strategies do people use to reduce cognitive dissonance and how effective are they? - [[User:Tatjurate|Tatjurate]] # [[/Colonisation and emotion in Australia/]] - What are the emotional responses to colonisation in Australia? - [[User:Micabaker1|Micabaker1]] # [[/Compassion/]] - What is compassion, what are its pros and cons, and how can it be fostered? - u3203545 # [[/Connection to country and well-being/]] - What is the relationship between connection to country and well-being? - [[User:MyUserName|MyUserName]] # [[/Contempt/]] - What is contempt, what causes it, and how can it be managed? - [[User:MyUserName|u3219905]] # [[/Core emotions/]] - What are the core emotions and what is their function? U3203140 # [[/Creative arts and trauma/]] - How can creative arts help in dealing with trauma? - [[MyUserName|SashaBrooksby]] # [[/Cultural influences on shame, guilt, and pride/]] - How does culture influence shame, guilt, and pride? - [[User:Tamika Afeaki|Tamika Afeaki]] # [[/Default mode network and the self/]] - What is the relationship between the DMN and the self? - [[User:MyUserName|MyUserName]] # [[/Difficult conversations and emotion/]] - What communication and emotional skills are needed to successfully negotiate difficult conversations? - [[User:u3158968|u3158968]] # [[/Disappointment/]] - What is disappointment, what causes disappointment, and how can disappointment be managed? - [[User:U3216256|U3216256]] # [[/DMT and spirituality/]] - How can DMT facilitate spiritual experiences? - [[DenniseSoleymani]] # [[/Durability bias in affective forecasting/]] - What role does durability bias play in affective forecasting? - [[User:MyUserName|MyUserName]] # [[/Ecological grief/]] - What is ecological grief and what can be done about it? - [[User:Brewerjr|Brewerjr]] # [[/Ecopsychology and stress/]] - How can ecopsychology help to explain and deal with stress? - [[User:MyUserName|MyUserName]] # [[/Embarrassment/]] - What is embarrassment, what causes it, and how can it be managed? - u3190353 # [[/Emotional intelligence training/]] - How can emotional intelligence be trained? - Eimilerous22 # [[/Emotion knowledge/]] - What is emotion knowledge and how can it be developed? - [[User:GabbieUC|GabbieUC]] # [[/Emotion across the lifespan/]] - How does emotion develop across the lifespan? - u3230861 # [[/Endocannabinoid system and emotion/]] - What is the role of the endocannabinoid system in emotion? - [[User:RWilliams12|Rwilliams12]] # [[/Environmental grief/]] - What is eco-grief, its causes and consequences, and what can be done? - [[User:Gabrielle Eagling|Gabrielle Eagling]] # [[/Exercise and endocannabinoids/]] - What is the relationship between exercise and the endocannabinoid system? - [[User:MyUserName|MyUserName]] # [[/Expressive suppression and emotion regulation/]] - What is the role of expressive suppression in emotion regulation? - [[U3131472]] # [[/Fairness and emotion/]] - What is the relation between fairness and emotion? - U3246554 # [[/Fatigue and emotion/]] - What is the effect of fatigue on emotion and what can be done about it? - [[User:Lewis.Kusk|Lewis.Kusk]] # [[/Fear/]] - What is fear, what causes it, and how can it be managed? - [[User:Icantchooseone|Icantchooseone]] # [[/Fear of working out/]] - What is FOWO and how can it be overcome? - [[User:MyUserName|MyUserName]] # [[/Fundamental attribution error and emotion/]] - What is the relationship between the FAE and emotion? - [[User:MyUserName|MyUserName]] # [[/Gratitude and subjective wellbeing/]] - What is the relationship between gratitude and subjective wellbeing? - [[User:MyUserName|MyUserName]] # [[/Gloatrage/]] - What is gloatrage, what causes it, and what are its consequences? - [[User:MyUserName|MyUserName]] # [[/Heart rate variability and emotion regulation/]] - What is the relationship between HRV and emotion regulation? - [[User:MyUserName|MyUserName]] # [[/Hedonic adaptation prevention model/]] - What is the HAP model and how can it be applied? - [[User:Lyndel Lemon|Lyndel Lemon]] # [[/Humility/]] - What is humility, what causes it, and is it desirable? - [[User:MyUserName|MyUserName]] # [[/Hypomania and emotion/]] - What are the emotional characteristics of hypomania? - [[User:Alec.cortez|Alec.cortez]] # [[/Impact bias/]] - What is impact bias, what causes it, what are its consequences, and how can it be avoided? - [[User:MyUserName|MyUserName]] # [[Indigenous Australian emotionality]] - In what ways is emotionality experienced by Indigenous Australian people? - [[User:U3189442 - K.Ryan|U3189442 - K.Ryan]] # [[/Indigenous Australian mindfulness/]] - How has Indigenous Australian culture traditionally conceived of, and practiced, mindfulness? - [[User:MyUserName|MyUserName]] # [[/Inspiration/]] - What is inspiration, what causes it, what are its consequences, and how can it be fostered? - [[User:MyUserName|u3227354]] # [[/Insular cortex and emotion/]] - What role does the insular cortex play in emotion? - [[User:U3190094|U3190094]] # [[/Interoception and emotion/]] - What is the relationship between interoception and emotion? - u3203265 # [[/Kama muta/]] - What is kama muta, what are its effects, and how can it be fostered? - [[User:U3183521|U3183521]] # [[/Linguistic relativism and emotion/]] - What is the role of linguistic relativism in emotion? - [[User:U3119310|U3119310]] # [[/Menstrual cycle mood disorders/]] - What causes menstrual cycle mood disorders and how can they be managed? - [[User:MyUserName|U3217109]] # [[/Mindfulness and creativity/]] - How can mindfulness enhance creativity? - [[CaityDcr1603]] # [[/Mindful self-care/]] - What is mindful self-care, why does it matter, and how can it be developed? - [[User:clairelogan|clairelogan]] # [[/Mixed emotions/]] - What are mixed emotions, what causes them, and how can they be managed? - [[User:MyUserName|u3210490]] # [[/Mudita/]] - What is mudita and how can it be developed? - [[User:MyUserName|MyUserName]] # [[/Natural disasters and emotion/]] - How do people respond emotionally to natural disasters and how can they be supported? -[[User:U3148366_Chris|U3148366_Chris]] # [[/Nature therapy/]] - What is nature therapy and how can it be applied? - Ana028 # [[/Narcissism and emotion/]] - What is the relationship between narcissism and emotion? - [[User:A Super Villain|A Super Villain]] # [[/Narrative therapy and emotion/]] - What is the role of emotion in narrative therapy? - [[User:MyUserName|MyUserName]] # [[/Needle fear/]] - How does needle fear develop, what are its consequences, and what can be done about it? - [[User:U3166273|U3166273]] # [[/Positivity ratio/]] - What is the positivity ratio and what are its implications? - [[User:MyUserName|MyUserName]] # [[/Post-traumatic stress disorder and emotion/]] - What is the effect of PTSD on emotion? - [[User:JorjaFive|JorjaFive]] # [[/Psychological distress/]] - What is PD, what are the main types, and how can they be managed? - [[User:U3190773|U3190773]] # [[/Psychological trauma/]] - What causes psychological trauma, what are the consequences, and how can people recover from psychological trauma? - [[User:U3210431|U3210431]] # [[/Psilocybin assisted psychotherapy/]] - How can psilocybin be used to assist psychotherapy? - [[User:U3083720|U3083720]] # [[/Rational compassion/]] - What is rational compassion and how can it be cultivated? - [[User:MyUserName|MyUserName]] # [[/Reflected glory/]] - What is reflected glory and what are its pros and cons? - [[User:MyUserName|MyUserName]] # [[/Religiosity and coping/]] - What is the relationship between religiosity and coping? - [[U3215326]] # [[/Resentment/]] - What is resentment, what causes it, and what are its consequences? - [[User:U3216389|U3216389]] # [[/Risk-as-feelings/]] - What is the emotional experience of risk and how does it influence decision-making and behaviour? - BenjiD'Ange # [[/Self-esteem and culture/]] - What are the cultural influences on self-esteem? - [[User:Jingru shao 0906|Jingru shao0906]] # [[/Smiling and emotion/]] - What is the relationship between smiling and emotion? - U3200902 # [[/Social media and suicide prevention/]] - How can social media be used to help prevent suicide? - [[JaimeTegan|JaimeTegan]] # [[/Sorry business/]] - What is sorry business and what role does it play in Indigenous communities in Australia? - Isaacem13 # [[/Stress control mindset/]] - What is a SCM, why does it matter, and how can it be cultivated? - # [[/Suffering as emotion/]] - What is the emotional experience of suffering and how can people cope with suffering? - [[User:Brookewin|Brookewin]] # [[/Telemental health/]] - What are the pros and cons of TMH and what are the key ingredients for effective TMH practices? - [[User:MyUserName|MyUserName]] # [[/Topophilia/]] - What is topophilia, how does it develop, and what are the psychological impacts? - [[User:RSPMeredith|RSPMeredith]] # [[/Triumph/]] - What is triumph, what causes it, and how can it be managed? - [[User:Bill.miosge|Bill.miosge]] # [[/Unemployment and mental health/]]: What is the relationship between unemployment and mental health? - [[User:MyUserName|U3216958 - Tiarna.Wilson-Ginn]] # [[/Viewing natural scenes and emotion/]] - What is the effect of viewing natural scenes on emotion and how can this be applied? - [[User:MyUserName|MyUserName]] # [[/Wave metaphor for emotion/]] - In what respects is an ocean wave a helpful metaphor for understanding human emotions? - [[jamieepiper]] # [[/Window of tolerance/]] - What is the window of tolerance and how this concept be used? - [[User:U3223109|U3223109]] # [[/Workplace mental health training/]] - What is WMHT, what techniques are used, and what are the impacts? - [[ArtOfHappiness]] # [[/Zoom fatigue/]] - What is Zoom fatigue, what causes it, what are its consequences, and what can be done about it? - [[User:u3211603|U3211603]] ==Motivation and emotion== # [[/Financial investing, motivation, and emotion/]] - What role does motivation and emotion play in financial investing? - [[U3217287|U3217287]] # [[/Hostage negotiation, motivation, and emotion/]] - What role does motivation and emotion play in hostage negotiation? - [[User:U3213549|U3213549]] # [[/Money priming, motivation, and emotion/]] - What is the effect of money priming on motivation and emotion? - [[User:Molzaroid|Molzaroid]] # [[/Motivational dimensional model of affect/]] - What is the motivational dimensional model of affect and what are its implications? - [[User:MyUserName|MyUserName]] # [[/Napping, motivation, and emotion/]] - What are the motivational and emotional effects of napping? - [[User:MyUserName|MyUserName]] # [[/Overchoice, emotion, and motivation/]] - What are the emotional and motivational effects of overchoice? - [[User:MyUserName|MyUserName]] # [[/Patience and impatience/]] - What are the psychological causes and consequences of patience and impatience? - [[User:u3100193|u3100193]] # [[/Reward system, motivation, and emotion/]] - What role does the reward system play in motivation and emotion? - [[User:U3162201|U3162201]] [[Category:Motivation and emotion/Book/2022]] or82hu4wn1cbpofwpyvmymep2sgo3a0 2414005 2414004 2022-08-12T20:49:45Z JimmyOC1985 2925861 /* Motivation */ wikitext text/x-wiki {{/Banner}} ==Motivation == # [[Academic help-seeking]] - What are the barriers and enablers of AHS and how can AHS be fostered? - [[User:Ibm4444|Ibm4444]] # [[/Academic self-regulation/]] - What is academic self-regulation, why does it matter, and how can it be fostered? - [[U3216563]] # [[/Actively open-minded thinking/]] - How can AOT be used to improve human performance? - [[User:MyUserName|MyUserName]] # [[/Active transport motivation/]] - What motivates use of active transport and how can people be encouraged to use it? - [[User:MyUserName|MyUserName]] # [[/Antidepressants and motivation/]] - What are the effects of popular antidepressants on motivation? - [[User:U3222363|U3222363]] # [[/Approach motivation/]] - What is approach motivation and how does it lead to behaviour? - [[User:U3189370|U3189370]] # [[/Behavioural economics and motivation/]] - What aspects of motivation theory are useful in behavioural economics? - [[User:U3141987|U3141987]] # [[/Behavioural model of health services/]] - What is the BMHS and how can it be used? - SoSilverLibby # [[/Beneficence as a psychological need/]] - What is beneficence and what are its implications as a psychological need? - [[User:MyUserName|CaitlinEmc]] # [[/Brief motivational interviewing as a health intervention/]] - How can brief motivational interviewing be used as a health intervention? - [[User:MyUserName|MyUserName]] # [[/Choice overload/]] - What is choice overload? What is the optimal amount of choice? - [[UserGeorgiaFairweather|GeorgiaFairweather]] # [[/Chunking and goal pursuit/]] - How does chunking affect goal pursuit? - GiovanniBartlett # [[/Cognitive entrenchment/]] - What is cognitive entrenchment and how can it be avoided? - [[JimmyOC1985|JimmyOC1985]] # [[/Climate change helplessness/]] - How does learned helpless impact motivation to engage in behaviours to limit climate change? - [[User:U3193000|U3193000]] # [[/Closeness communication bias/]] - What is the CCB, why does it occur, and how can it be overcome? - [[User:U3215103|U3215103]] # [[/Commitment bias/]] - What motivates escalation of commitment even it does not lead to desirably outcomes? - [[User:MyUserName|MyUserName]] # [[/Conspiracy theory motivation/]] - What motivates people to believe in conspiracy theories? - [[User:KingMob221|KingMob221]] # [[/Construal level theory/]] - What is construal level theory and how can it be applied? - [[User:MyUserName|MyUserName]] # [[/Courage motivation/]] - What is courage, what motivates courage, and how can courage be enhanced? -[[User:Hanarose123|Hanarose123]] # [[/Death drive/]] - What is the death drive and how can it be negotiated? - [[User:U3086459|U3086459]] # [[Motivation and emotion/Book/2022/Drugs-violence nexus and motivation|Drugs-violence nexus and motivation]] - What is the role of motivation in the drugs-violence nexus? - [[Atu3202070|Atu3202070]] # [[/Episodic future thinking and delay discounting/]] - What is the relationship between between EFT and DD? - [[User:MyUserName|MyUserName]] # [[/Episodic memory and planning/]] - What role does episodic memory play in planning? - [[User:MyUserName|U3246310]] # [[/Equity theory/]] - What is equity theory and how can it be applied? - [[EKS2001|EKS2001]] # [[/ERG theory/]] - What is Alderfer's ERG theory? - [[User:MyUserName|MyUserName]] # [[/Frame of reference and motivation/]] - How does frame of reference affect motivation? - [[User:MyUserName|MyUserName]] # [[/Freedom and motivation/]] - What is the effect of freedom on motivation? - [[Cedevlin9|Cedevlin9]] # [[/Fully functioning person/]] - What is a FFP and how can full functioning be developed? - [[User:Sebastian Armstrong|Sebastian Armstrong]] # [[/Functional fixedness/]] - What is functional fixedness and how can it be overcome? - [[User:U3214117|U3214117]] # [[/Functional imagery training/]] - What is FIT and how can it be applied? - [[User:Btarmstrong24|Btarmstrong24]] # [[/Gamification and work motivation/]] - How can gamification enhance work motivation? - [[U3211125|U3211125]] # [[/Giving up goals/]] - When should we give up goals and when should we persist? - [[User:MyUserName|U3161584]] # [[/Green prescription motivation/]] - What motivates green prescription compliance? - [[User:Earthxangel|Earthxangel]] # [[/Health belief model/]] - What is the HBM and how can it be used to enhance motivation for health-promoting behaviour? - [[SoSilverLibby]] # [[/Help-seeking among boys/]] - What are the barriers to help-seeking for boys and what motivates them to seek help? - [[User:BradMcGrath|BradMcGrath]] # [[/Hidden costs of reward/]] - What are the hidden costs of motivating by reward? - [[User:SLoCE|u3033296]] # [[/Hijack hypothesis of drug addiction/]] - What is the hijack hypothesis, what is the evidence, and how does it help to understand drug addiction? - [[U3218292|U3218292]] # [[/Honesty motivation/]] - What motivates honesty? - [[User:U3200859|U3200859]] # [[/Humour, leadership, and work/]] - What role does humour play in effective leadership in the workplace? - [[User:U3210264|U3210264]] # [[/IKEA effect/]] - What is the IKEA effect and how can it be applied? - [[U3216963|U]]3216963 # [[/Intertemporal choice/]] - What are intertemporal choices and how can they be effectively negotiated? - [[User:MyUserName|MyUserName]] # [[/Kindness motivation/]] - What motivates kindness? - [[User:U3205429|U3205429]] # [[/Motivational music and exercise/]] - How can music be used to help motivate exercise? - [[User:MyUserName|U3183466]] # [[/Novelty-variety as a psychological need/]] - What is novelty-variety and what are its implications as a psychological need? - [[User:MyUserName|MyUserName]] # [[/Nucleus accumbens and motivation/]] - What role does the nucleus accumbens play in motivation? - [[User:U3213250|U3213250]] # [[/Perfectionism/]] - What motivates perfectionism? Is perfectionism good or bad? How can it be managed? - [[User:AEMOR|AEMOR]] # [[/Physiological needs/]] - How do human's physiological needs affect motivation? - [[U3203655]] # [[/Protection motivation theory and COVID-19/]] - How does PMT apply to managing COVID-19? - [[User:U3200956|U3200956]] # [[/Relative deprivation and motivation/]] - What is the effect of relative deprivation on motivation? - [[User:U3191574 (PHP)|U3191574 (PHP)]] # [[/Retrospective regret/]] - What is the motivational role of retrospective regret? - [[User:Will-U3214082|Will-U3214082]] # [[/Revenge motivation/]] - What motivates revenge and how does it affect us? - [[User:U3216654|U3216654]] # [[/Self-efficacy and academic achievement/]] - What role does self-efficacy play in academic achievement? - [[User:U943292|U943292]]a # [[/Self-efficacy and achievement/]] - What role does self-efficacy play in achievement outcomes? - [[User:U3216513mt|U3216513mt]] # [[/Sexual harassment at work motivation/]] - What motivates sexual harassment at work and what can be done about it? - [[User:U3037979|U3037979]] # [[/Signature strengths/]] - What are signature strengths and how can they be applied? - [[User:MyUserName|MyUserName]] # [[/Social cure/]] - What is the social cure and how can it be applied? - [[User:U3215976|U3215976]] # [[/System justification theory/]] - What is SJT, how does it affect our lives, and what can be done about it? - [[User:MyUserName|MyUserName]] # [[/Stretch goals/]] - What are stretch goals? Do they work? - [[User:MyUserName|MyUserName]] # [[/Sublimation/]] - What is sublimation and how can it be fostered? - [[User:MyUserName|MyUserName]] # [[/Survival needs and motivation/]] - What are survival needs and how do they influence motivation? - [[User:U3148161|U3148161]] # [[/Task initiation/]] - What are the challenges with task initiation and how to get get started? - [[User:MyUserName|U3210006]] # [[/Theoretical domains framework/]] - What is the TDF and how can be used to guide behaviour change? - [[User:MyUserName|MyUserName]] # [[/Time and motivation/]] - What is the effect of time on motivation? - [[User:Lturner2311|Lturner2311]] # [[/Time management/]] - How can one's time be managed effectively? - [[User:CNK.20|CNK.20]] # [[/To-do lists/]] - Are to-do lists a good idea? What are their pros and cons? How can they be used effectively? - [[User:U3207458|U3207458]] # [[/Uncertainty avoidance/]] - What is uncertainty avoidance, why does it occur, and what are its consequences? - [[User:Franklin Brightt|Franklin Brightt]] # [[/Urgency bias and productivity/]] - What is the impact of urgency bias on productivity and what can be done about it? - U3055143 # [[/Vocational identity/]] - What is vocational identity and how does it develop? - [[User:MyUserName|MyUserName]] # [[/Volunteer tourism motivation/]] - What motivates volunteer tourism? - [[User:U962051|U962051]] # [[/Wanting and liking/]] - What are the similarities and differences between wanting and liking, and what are the implications? - [[U3201643]] # [[/Work breaks, well-being, and productivity/]] - How do work breaks affect well-being and productivity? - [[User:MyUserName|U3215603]] # [[/Work and flow/]] - What characteristics of work can produce flow and how can flow at work be fostered? - [[User:U3213441|U3213441]] ==Emotion== # [[/Animal emotion/]] - What is the emotional experience of animals? - [[U3216502]] # [[/Attributions and emotion/]] - How do attributions affect emotion? - [[User:MyUserName|MyUserName]] # [[/Autonomous sensory meridian response and emotion/]] - What emotions are involved in ASMR experiences and why do they occur? - [[User:U3186959|U3186959]] # [[/Benzodiazepines and emotion/]] - What are the effects of benzodiazepines on emotion? - [[User:FulaAjeo22|FulaAjeo22]] # [[/Bewilderment/]] - What is bewilderment and how can it be dealt with? - SunandaUC # [[/Burnout/]] - What is burnout and how can be it be managed and prevented? - [[U3202788]] # [[/Cognitive dissonance reduction/]] - What strategies do people use to reduce cognitive dissonance and how effective are they? - [[User:Tatjurate|Tatjurate]] # [[/Colonisation and emotion in Australia/]] - What are the emotional responses to colonisation in Australia? - [[User:Micabaker1|Micabaker1]] # [[/Compassion/]] - What is compassion, what are its pros and cons, and how can it be fostered? - u3203545 # [[/Connection to country and well-being/]] - What is the relationship between connection to country and well-being? - [[User:MyUserName|MyUserName]] # [[/Contempt/]] - What is contempt, what causes it, and how can it be managed? - [[User:MyUserName|u3219905]] # [[/Core emotions/]] - What are the core emotions and what is their function? U3203140 # [[/Creative arts and trauma/]] - How can creative arts help in dealing with trauma? - [[MyUserName|SashaBrooksby]] # [[/Cultural influences on shame, guilt, and pride/]] - How does culture influence shame, guilt, and pride? - [[User:Tamika Afeaki|Tamika Afeaki]] # [[/Default mode network and the self/]] - What is the relationship between the DMN and the self? - [[User:MyUserName|MyUserName]] # [[/Difficult conversations and emotion/]] - What communication and emotional skills are needed to successfully negotiate difficult conversations? - [[User:u3158968|u3158968]] # [[/Disappointment/]] - What is disappointment, what causes disappointment, and how can disappointment be managed? - [[User:U3216256|U3216256]] # [[/DMT and spirituality/]] - How can DMT facilitate spiritual experiences? - [[DenniseSoleymani]] # [[/Durability bias in affective forecasting/]] - What role does durability bias play in affective forecasting? - [[User:MyUserName|MyUserName]] # [[/Ecological grief/]] - What is ecological grief and what can be done about it? - [[User:Brewerjr|Brewerjr]] # [[/Ecopsychology and stress/]] - How can ecopsychology help to explain and deal with stress? - [[User:MyUserName|MyUserName]] # [[/Embarrassment/]] - What is embarrassment, what causes it, and how can it be managed? - u3190353 # [[/Emotional intelligence training/]] - How can emotional intelligence be trained? - Eimilerous22 # [[/Emotion knowledge/]] - What is emotion knowledge and how can it be developed? - [[User:GabbieUC|GabbieUC]] # [[/Emotion across the lifespan/]] - How does emotion develop across the lifespan? - u3230861 # [[/Endocannabinoid system and emotion/]] - What is the role of the endocannabinoid system in emotion? - [[User:RWilliams12|Rwilliams12]] # [[/Environmental grief/]] - What is eco-grief, its causes and consequences, and what can be done? - [[User:Gabrielle Eagling|Gabrielle Eagling]] # [[/Exercise and endocannabinoids/]] - What is the relationship between exercise and the endocannabinoid system? - [[User:MyUserName|MyUserName]] # [[/Expressive suppression and emotion regulation/]] - What is the role of expressive suppression in emotion regulation? - [[U3131472]] # [[/Fairness and emotion/]] - What is the relation between fairness and emotion? - U3246554 # [[/Fatigue and emotion/]] - What is the effect of fatigue on emotion and what can be done about it? - [[User:Lewis.Kusk|Lewis.Kusk]] # [[/Fear/]] - What is fear, what causes it, and how can it be managed? - [[User:Icantchooseone|Icantchooseone]] # [[/Fear of working out/]] - What is FOWO and how can it be overcome? - [[User:MyUserName|MyUserName]] # [[/Fundamental attribution error and emotion/]] - What is the relationship between the FAE and emotion? - [[User:MyUserName|MyUserName]] # [[/Gratitude and subjective wellbeing/]] - What is the relationship between gratitude and subjective wellbeing? - [[User:MyUserName|MyUserName]] # [[/Gloatrage/]] - What is gloatrage, what causes it, and what are its consequences? - [[User:MyUserName|MyUserName]] # [[/Heart rate variability and emotion regulation/]] - What is the relationship between HRV and emotion regulation? - [[User:MyUserName|MyUserName]] # [[/Hedonic adaptation prevention model/]] - What is the HAP model and how can it be applied? - [[User:Lyndel Lemon|Lyndel Lemon]] # [[/Humility/]] - What is humility, what causes it, and is it desirable? - [[User:MyUserName|MyUserName]] # [[/Hypomania and emotion/]] - What are the emotional characteristics of hypomania? - [[User:Alec.cortez|Alec.cortez]] # [[/Impact bias/]] - What is impact bias, what causes it, what are its consequences, and how can it be avoided? - [[User:MyUserName|MyUserName]] # [[Indigenous Australian emotionality]] - In what ways is emotionality experienced by Indigenous Australian people? - [[User:U3189442 - K.Ryan|U3189442 - K.Ryan]] # [[/Indigenous Australian mindfulness/]] - How has Indigenous Australian culture traditionally conceived of, and practiced, mindfulness? - [[User:MyUserName|MyUserName]] # [[/Inspiration/]] - What is inspiration, what causes it, what are its consequences, and how can it be fostered? - [[User:MyUserName|u3227354]] # [[/Insular cortex and emotion/]] - What role does the insular cortex play in emotion? - [[User:U3190094|U3190094]] # [[/Interoception and emotion/]] - What is the relationship between interoception and emotion? - u3203265 # [[/Kama muta/]] - What is kama muta, what are its effects, and how can it be fostered? - [[User:U3183521|U3183521]] # [[/Linguistic relativism and emotion/]] - What is the role of linguistic relativism in emotion? - [[User:U3119310|U3119310]] # [[/Menstrual cycle mood disorders/]] - What causes menstrual cycle mood disorders and how can they be managed? - [[User:MyUserName|U3217109]] # [[/Mindfulness and creativity/]] - How can mindfulness enhance creativity? - [[CaityDcr1603]] # [[/Mindful self-care/]] - What is mindful self-care, why does it matter, and how can it be developed? - [[User:clairelogan|clairelogan]] # [[/Mixed emotions/]] - What are mixed emotions, what causes them, and how can they be managed? - [[User:MyUserName|u3210490]] # [[/Mudita/]] - What is mudita and how can it be developed? - [[User:MyUserName|MyUserName]] # [[/Natural disasters and emotion/]] - How do people respond emotionally to natural disasters and how can they be supported? -[[User:U3148366_Chris|U3148366_Chris]] # [[/Nature therapy/]] - What is nature therapy and how can it be applied? - Ana028 # [[/Narcissism and emotion/]] - What is the relationship between narcissism and emotion? - [[User:A Super Villain|A Super Villain]] # [[/Narrative therapy and emotion/]] - What is the role of emotion in narrative therapy? - [[User:MyUserName|MyUserName]] # [[/Needle fear/]] - How does needle fear develop, what are its consequences, and what can be done about it? - [[User:U3166273|U3166273]] # [[/Positivity ratio/]] - What is the positivity ratio and what are its implications? - [[User:MyUserName|MyUserName]] # [[/Post-traumatic stress disorder and emotion/]] - What is the effect of PTSD on emotion? - [[User:JorjaFive|JorjaFive]] # [[/Psychological distress/]] - What is PD, what are the main types, and how can they be managed? - [[User:U3190773|U3190773]] # [[/Psychological trauma/]] - What causes psychological trauma, what are the consequences, and how can people recover from psychological trauma? - [[User:U3210431|U3210431]] # [[/Psilocybin assisted psychotherapy/]] - How can psilocybin be used to assist psychotherapy? - [[User:U3083720|U3083720]] # [[/Rational compassion/]] - What is rational compassion and how can it be cultivated? - [[User:MyUserName|MyUserName]] # [[/Reflected glory/]] - What is reflected glory and what are its pros and cons? - [[User:MyUserName|MyUserName]] # [[/Religiosity and coping/]] - What is the relationship between religiosity and coping? - [[U3215326]] # [[/Resentment/]] - What is resentment, what causes it, and what are its consequences? - [[User:U3216389|U3216389]] # [[/Risk-as-feelings/]] - What is the emotional experience of risk and how does it influence decision-making and behaviour? - BenjiD'Ange # [[/Self-esteem and culture/]] - What are the cultural influences on self-esteem? - [[User:Jingru shao 0906|Jingru shao0906]] # [[/Smiling and emotion/]] - What is the relationship between smiling and emotion? - U3200902 # [[/Social media and suicide prevention/]] - How can social media be used to help prevent suicide? - [[JaimeTegan|JaimeTegan]] # [[/Sorry business/]] - What is sorry business and what role does it play in Indigenous communities in Australia? - Isaacem13 # [[/Stress control mindset/]] - What is a SCM, why does it matter, and how can it be cultivated? - # [[/Suffering as emotion/]] - What is the emotional experience of suffering and how can people cope with suffering? - [[User:Brookewin|Brookewin]] # [[/Telemental health/]] - What are the pros and cons of TMH and what are the key ingredients for effective TMH practices? - [[User:MyUserName|MyUserName]] # [[/Topophilia/]] - What is topophilia, how does it develop, and what are the psychological impacts? - [[User:RSPMeredith|RSPMeredith]] # [[/Triumph/]] - What is triumph, what causes it, and how can it be managed? - [[User:Bill.miosge|Bill.miosge]] # [[/Unemployment and mental health/]]: What is the relationship between unemployment and mental health? - [[User:MyUserName|U3216958 - Tiarna.Wilson-Ginn]] # [[/Viewing natural scenes and emotion/]] - What is the effect of viewing natural scenes on emotion and how can this be applied? - [[User:MyUserName|MyUserName]] # [[/Wave metaphor for emotion/]] - In what respects is an ocean wave a helpful metaphor for understanding human emotions? - [[jamieepiper]] # [[/Window of tolerance/]] - What is the window of tolerance and how this concept be used? - [[User:U3223109|U3223109]] # [[/Workplace mental health training/]] - What is WMHT, what techniques are used, and what are the impacts? - [[ArtOfHappiness]] # [[/Zoom fatigue/]] - What is Zoom fatigue, what causes it, what are its consequences, and what can be done about it? - [[User:u3211603|U3211603]] ==Motivation and emotion== # [[/Financial investing, motivation, and emotion/]] - What role does motivation and emotion play in financial investing? - [[U3217287|U3217287]] # [[/Hostage negotiation, motivation, and emotion/]] - What role does motivation and emotion play in hostage negotiation? - [[User:U3213549|U3213549]] # [[/Money priming, motivation, and emotion/]] - What is the effect of money priming on motivation and emotion? - [[User:Molzaroid|Molzaroid]] # [[/Motivational dimensional model of affect/]] - What is the motivational dimensional model of affect and what are its implications? - [[User:MyUserName|MyUserName]] # [[/Napping, motivation, and emotion/]] - What are the motivational and emotional effects of napping? - [[User:MyUserName|MyUserName]] # [[/Overchoice, emotion, and motivation/]] - What are the emotional and motivational effects of overchoice? - [[User:MyUserName|MyUserName]] # [[/Patience and impatience/]] - What are the psychological causes and consequences of patience and impatience? - [[User:u3100193|u3100193]] # [[/Reward system, motivation, and emotion/]] - What role does the reward system play in motivation and emotion? - [[User:U3162201|U3162201]] [[Category:Motivation and emotion/Book/2022]] knnqaap2tynscs98ctvbcpybmltzbw3 2414006 2414005 2022-08-12T20:50:27Z JimmyOC1985 2925861 /* Emotion */ wikitext text/x-wiki {{/Banner}} ==Motivation == # [[Academic help-seeking]] - What are the barriers and enablers of AHS and how can AHS be fostered? - [[User:Ibm4444|Ibm4444]] # [[/Academic self-regulation/]] - What is academic self-regulation, why does it matter, and how can it be fostered? - [[U3216563]] # [[/Actively open-minded thinking/]] - How can AOT be used to improve human performance? - [[User:MyUserName|MyUserName]] # [[/Active transport motivation/]] - What motivates use of active transport and how can people be encouraged to use it? - [[User:MyUserName|MyUserName]] # [[/Antidepressants and motivation/]] - What are the effects of popular antidepressants on motivation? - [[User:U3222363|U3222363]] # [[/Approach motivation/]] - What is approach motivation and how does it lead to behaviour? - [[User:U3189370|U3189370]] # [[/Behavioural economics and motivation/]] - What aspects of motivation theory are useful in behavioural economics? - [[User:U3141987|U3141987]] # [[/Behavioural model of health services/]] - What is the BMHS and how can it be used? - SoSilverLibby # [[/Beneficence as a psychological need/]] - What is beneficence and what are its implications as a psychological need? - [[User:MyUserName|CaitlinEmc]] # [[/Brief motivational interviewing as a health intervention/]] - How can brief motivational interviewing be used as a health intervention? - [[User:MyUserName|MyUserName]] # [[/Choice overload/]] - What is choice overload? What is the optimal amount of choice? - [[UserGeorgiaFairweather|GeorgiaFairweather]] # [[/Chunking and goal pursuit/]] - How does chunking affect goal pursuit? - GiovanniBartlett # [[/Cognitive entrenchment/]] - What is cognitive entrenchment and how can it be avoided? - [[JimmyOC1985|JimmyOC1985]] # [[/Climate change helplessness/]] - How does learned helpless impact motivation to engage in behaviours to limit climate change? - [[User:U3193000|U3193000]] # [[/Closeness communication bias/]] - What is the CCB, why does it occur, and how can it be overcome? - [[User:U3215103|U3215103]] # [[/Commitment bias/]] - What motivates escalation of commitment even it does not lead to desirably outcomes? - [[User:MyUserName|MyUserName]] # [[/Conspiracy theory motivation/]] - What motivates people to believe in conspiracy theories? - [[User:KingMob221|KingMob221]] # [[/Construal level theory/]] - What is construal level theory and how can it be applied? - [[User:MyUserName|MyUserName]] # [[/Courage motivation/]] - What is courage, what motivates courage, and how can courage be enhanced? -[[User:Hanarose123|Hanarose123]] # [[/Death drive/]] - What is the death drive and how can it be negotiated? - [[User:U3086459|U3086459]] # [[Motivation and emotion/Book/2022/Drugs-violence nexus and motivation|Drugs-violence nexus and motivation]] - What is the role of motivation in the drugs-violence nexus? - [[Atu3202070|Atu3202070]] # [[/Episodic future thinking and delay discounting/]] - What is the relationship between between EFT and DD? - [[User:MyUserName|MyUserName]] # [[/Episodic memory and planning/]] - What role does episodic memory play in planning? - [[User:MyUserName|U3246310]] # [[/Equity theory/]] - What is equity theory and how can it be applied? - [[EKS2001|EKS2001]] # [[/ERG theory/]] - What is Alderfer's ERG theory? - [[User:MyUserName|MyUserName]] # [[/Frame of reference and motivation/]] - How does frame of reference affect motivation? - [[User:MyUserName|MyUserName]] # [[/Freedom and motivation/]] - What is the effect of freedom on motivation? - [[Cedevlin9|Cedevlin9]] # [[/Fully functioning person/]] - What is a FFP and how can full functioning be developed? - [[User:Sebastian Armstrong|Sebastian Armstrong]] # [[/Functional fixedness/]] - What is functional fixedness and how can it be overcome? - [[User:U3214117|U3214117]] # [[/Functional imagery training/]] - What is FIT and how can it be applied? - [[User:Btarmstrong24|Btarmstrong24]] # [[/Gamification and work motivation/]] - How can gamification enhance work motivation? - [[U3211125|U3211125]] # [[/Giving up goals/]] - When should we give up goals and when should we persist? - [[User:MyUserName|U3161584]] # [[/Green prescription motivation/]] - What motivates green prescription compliance? - [[User:Earthxangel|Earthxangel]] # [[/Health belief model/]] - What is the HBM and how can it be used to enhance motivation for health-promoting behaviour? - [[SoSilverLibby]] # [[/Help-seeking among boys/]] - What are the barriers to help-seeking for boys and what motivates them to seek help? - [[User:BradMcGrath|BradMcGrath]] # [[/Hidden costs of reward/]] - What are the hidden costs of motivating by reward? - [[User:SLoCE|u3033296]] # [[/Hijack hypothesis of drug addiction/]] - What is the hijack hypothesis, what is the evidence, and how does it help to understand drug addiction? - [[U3218292|U3218292]] # [[/Honesty motivation/]] - What motivates honesty? - [[User:U3200859|U3200859]] # [[/Humour, leadership, and work/]] - What role does humour play in effective leadership in the workplace? - [[User:U3210264|U3210264]] # [[/IKEA effect/]] - What is the IKEA effect and how can it be applied? - [[U3216963|U]]3216963 # [[/Intertemporal choice/]] - What are intertemporal choices and how can they be effectively negotiated? - [[User:MyUserName|MyUserName]] # [[/Kindness motivation/]] - What motivates kindness? - [[User:U3205429|U3205429]] # [[/Motivational music and exercise/]] - How can music be used to help motivate exercise? - [[User:MyUserName|U3183466]] # [[/Novelty-variety as a psychological need/]] - What is novelty-variety and what are its implications as a psychological need? - [[User:MyUserName|MyUserName]] # [[/Nucleus accumbens and motivation/]] - What role does the nucleus accumbens play in motivation? - [[User:U3213250|U3213250]] # [[/Perfectionism/]] - What motivates perfectionism? Is perfectionism good or bad? How can it be managed? - [[User:AEMOR|AEMOR]] # [[/Physiological needs/]] - How do human's physiological needs affect motivation? - [[U3203655]] # [[/Protection motivation theory and COVID-19/]] - How does PMT apply to managing COVID-19? - [[User:U3200956|U3200956]] # [[/Relative deprivation and motivation/]] - What is the effect of relative deprivation on motivation? - [[User:U3191574 (PHP)|U3191574 (PHP)]] # [[/Retrospective regret/]] - What is the motivational role of retrospective regret? - [[User:Will-U3214082|Will-U3214082]] # [[/Revenge motivation/]] - What motivates revenge and how does it affect us? - [[User:U3216654|U3216654]] # [[/Self-efficacy and academic achievement/]] - What role does self-efficacy play in academic achievement? - [[User:U943292|U943292]]a # [[/Self-efficacy and achievement/]] - What role does self-efficacy play in achievement outcomes? - [[User:U3216513mt|U3216513mt]] # [[/Sexual harassment at work motivation/]] - What motivates sexual harassment at work and what can be done about it? - [[User:U3037979|U3037979]] # [[/Signature strengths/]] - What are signature strengths and how can they be applied? - [[User:MyUserName|MyUserName]] # [[/Social cure/]] - What is the social cure and how can it be applied? - [[User:U3215976|U3215976]] # [[/System justification theory/]] - What is SJT, how does it affect our lives, and what can be done about it? - [[User:MyUserName|MyUserName]] # [[/Stretch goals/]] - What are stretch goals? Do they work? - [[User:MyUserName|MyUserName]] # [[/Sublimation/]] - What is sublimation and how can it be fostered? - [[User:MyUserName|MyUserName]] # [[/Survival needs and motivation/]] - What are survival needs and how do they influence motivation? - [[User:U3148161|U3148161]] # [[/Task initiation/]] - What are the challenges with task initiation and how to get get started? - [[User:MyUserName|U3210006]] # [[/Theoretical domains framework/]] - What is the TDF and how can be used to guide behaviour change? - [[User:MyUserName|MyUserName]] # [[/Time and motivation/]] - What is the effect of time on motivation? - [[User:Lturner2311|Lturner2311]] # [[/Time management/]] - How can one's time be managed effectively? - [[User:CNK.20|CNK.20]] # [[/To-do lists/]] - Are to-do lists a good idea? What are their pros and cons? How can they be used effectively? - [[User:U3207458|U3207458]] # [[/Uncertainty avoidance/]] - What is uncertainty avoidance, why does it occur, and what are its consequences? - [[User:Franklin Brightt|Franklin Brightt]] # [[/Urgency bias and productivity/]] - What is the impact of urgency bias on productivity and what can be done about it? - U3055143 # [[/Vocational identity/]] - What is vocational identity and how does it develop? - [[User:MyUserName|MyUserName]] # [[/Volunteer tourism motivation/]] - What motivates volunteer tourism? - [[User:U962051|U962051]] # [[/Wanting and liking/]] - What are the similarities and differences between wanting and liking, and what are the implications? - [[U3201643]] # [[/Work breaks, well-being, and productivity/]] - How do work breaks affect well-being and productivity? - [[User:MyUserName|U3215603]] # [[/Work and flow/]] - What characteristics of work can produce flow and how can flow at work be fostered? - [[User:U3213441|U3213441]] ==Emotion== # [[/Animal emotion/]] - What is the emotional experience of animals? - [[U3216502]] # [[/Attributions and emotion/]] - How do attributions affect emotion? - [[User:MyUserName|MyUserName]] # [[/Autonomous sensory meridian response and emotion/]] - What emotions are involved in ASMR experiences and why do they occur? - [[User:U3186959|U3186959]] # [[/Benzodiazepines and emotion/]] - What are the effects of benzodiazepines on emotion? - [[User:FulaAjeo22|FulaAjeo22]] # [[/Bewilderment/]] - What is bewilderment and how can it be dealt with? - SunandaUC # [[/Burnout/]] - What is burnout and how can be it be managed and prevented? - [[U3202788]] # [[/Cognitive dissonance reduction/]] - What strategies do people use to reduce cognitive dissonance and how effective are they? - [[User:Tatjurate|Tatjurate]] # [[/Colonisation and emotion in Australia/]] - What are the emotional responses to colonisation in Australia? - [[User:Micabaker1|Micabaker1]] # [[/Compassion/]] - What is compassion, what are its pros and cons, and how can it be fostered? - u3203545 # [[/Connection to country and well-being/]] - What is the relationship between connection to country and well-being? - [[User:MyUserName|MyUserName]] # [[/Contempt/]] - What is contempt, what causes it, and how can it be managed? - [[User:MyUserName|u3219905]] # [[/Core emotions/]] - What are the core emotions and what is their function? U3203140 # [[/Creative arts and trauma/]] - How can creative arts help in dealing with trauma? - [[MyUserName|SashaBrooksby]] # [[/Cultural influences on shame, guilt, and pride/]] - How does culture influence shame, guilt, and pride? - [[User:Tamika Afeaki|Tamika Afeaki]] # [[/Default mode network and the self/]] - What is the relationship between the DMN and the self? - [[User:MyUserName|MyUserName]] # [[/Difficult conversations and emotion/]] - What communication and emotional skills are needed to successfully negotiate difficult conversations? - [[User:u3158968|u3158968]] # [[/Disappointment/]] - What is disappointment, what causes disappointment, and how can disappointment be managed? - [[User:U3216256|U3216256]] # [[/DMT and spirituality/]] - How can DMT facilitate spiritual experiences? - [[DenniseSoleymani]] # [[/Durability bias in affective forecasting/]] - What role does durability bias play in affective forecasting? - [[User:MyUserName|MyUserName]] # [[/Ecological grief/]] - What is ecological grief and what can be done about it? - [[User:Brewerjr|Brewerjr]] # [[/Ecopsychology and stress/]] - How can ecopsychology help to explain and deal with stress? - [[User:MyUserName|MyUserName]] # [[/Embarrassment/]] - What is embarrassment, what causes it, and how can it be managed? - u3190353 # [[/Emotional intelligence training/]] - How can emotional intelligence be trained? - Eimilerous22 # [[/Emotion knowledge/]] - What is emotion knowledge and how can it be developed? - [[User:GabbieUC|GabbieUC]] # [[/Emotion across the lifespan/]] - How does emotion develop across the lifespan? - u3230861 # [[/Endocannabinoid system and emotion/]] - What is the role of the endocannabinoid system in emotion? - [[User:RWilliams12|Rwilliams12]] # [[/Environmental grief/]] - What is eco-grief, its causes and consequences, and what can be done? - [[User:Gabrielle Eagling|Gabrielle Eagling]] # [[/Exercise and endocannabinoids/]] - What is the relationship between exercise and the endocannabinoid system? - [[User:MyUserName|MyUserName]] # [[/Expressive suppression and emotion regulation/]] - What is the role of expressive suppression in emotion regulation? - [[U3131472]] # [[/Fairness and emotion/]] - What is the relation between fairness and emotion? - U3246554 # [[/Fatigue and emotion/]] - What is the effect of fatigue on emotion and what can be done about it? - [[User:Lewis.Kusk|Lewis.Kusk]] # [[/Fear/]] - What is fear, what causes it, and how can it be managed? - [[User:Icantchooseone|Icantchooseone]] # [[/Fear of working out/]] - What is FOWO and how can it be overcome? - [[User:MyUserName|MyUserName]] # [[/Fundamental attribution error and emotion/]] - What is the relationship between the FAE and emotion? - [[User:MyUserName|MyUserName]] # [[/Gratitude and subjective wellbeing/]] - What is the relationship between gratitude and subjective wellbeing? - [[User:MyUserName|MyUserName]] # [[/Gloatrage/]] - What is gloatrage, what causes it, and what are its consequences? - [[User:MyUserName|MyUserName]] # [[/Heart rate variability and emotion regulation/]] - What is the relationship between HRV and emotion regulation? - [[User:MyUserName|MyUserName]] # [[/Hedonic adaptation prevention model/]] - What is the HAP model and how can it be applied? - [[User:Lyndel Lemon|Lyndel Lemon]] # [[/Humility/]] - What is humility, what causes it, and is it desirable? - [[User:MyUserName|MyUserName]] # [[/Hypomania and emotion/]] - What are the emotional characteristics of hypomania? - [[User:Alec.cortez|Alec.cortez]] # [[/Impact bias/]] - What is impact bias, what causes it, what are its consequences, and how can it be avoided? - [[User:MyUserName|MyUserName]] # [[Indigenous Australian emotionality]] - In what ways is emotionality experienced by Indigenous Australian people? - [[User:U3189442 - K.Ryan|U3189442 - K.Ryan]] # [[/Indigenous Australian mindfulness/]] - How has Indigenous Australian culture traditionally conceived of, and practiced, mindfulness? - [[User:MyUserName|MyUserName]] # [[/Inspiration/]] - What is inspiration, what causes it, what are its consequences, and how can it be fostered? - [[User:MyUserName|u3227354]] # [[/Insular cortex and emotion/]] - What role does the insular cortex play in emotion? - [[User:U3190094|U3190094]] # [[/Interoception and emotion/]] - What is the relationship between interoception and emotion? - u3203265 # [[/Kama muta/]] - What is kama muta, what are its effects, and how can it be fostered? - [[User:U3183521|U3183521]] # [[/Linguistic relativism and emotion/]] - What is the role of linguistic relativism in emotion? - [[User:U3119310|U3119310]] # [[/Menstrual cycle mood disorders/]] - What causes menstrual cycle mood disorders and how can they be managed? - [[User:MyUserName|U3217109]] # [[/Mindfulness and creativity/]] - How can mindfulness enhance creativity? - [[CaityDcr1603]] # [[/Mindful self-care/]] - What is mindful self-care, why does it matter, and how can it be developed? - [[User:clairelogan|clairelogan]] # [[/Mixed emotions/]] - What are mixed emotions, what causes them, and how can they be managed? - [[User:MyUserName|u3210490]] # [[/Mudita/]] - What is mudita and how can it be developed? - [[User:MyUserName|MyUserName]] # [[/Natural disasters and emotion/]] - How do people respond emotionally to natural disasters and how can they be supported? -[[User:U3148366_Chris|U3148366_Chris]] # [[/Nature therapy/]] - What is nature therapy and how can it be applied? - Ana028 # [[/Narcissism and emotion/]] - What is the relationship between narcissism and emotion? - [[User:A Super Villain|A Super Villain]] # [[/Narrative therapy and emotion/]] - What is the role of emotion in narrative therapy? - [[User:MyUserName|MyUserName]] # [[/Needle fear/]] - How does needle fear develop, what are its consequences, and what can be done about it? - [[User:U3166273|U3166273]] # [[/Positivity ratio/]] - What is the positivity ratio and what are its implications? - [[User:MyUserName|MyUserName]] # [[/Post-traumatic stress disorder and emotion/]] - What is the effect of PTSD on emotion? - [[User:JorjaFive|JorjaFive]] # [[/Psychological distress/]] - What is PD, what are the main types, and how can they be managed? - [[User:U3190773|U3190773]] # [[/Psychological trauma/]] - What causes psychological trauma, what are the consequences, and how can people recover from psychological trauma? - [[User:U3210431|U3210431]] # [[/Psilocybin assisted psychotherapy/]] - How can psilocybin be used to assist psychotherapy? - [[User:U3083720|U3083720]] # [[/Rational compassion/]] - What is rational compassion and how can it be cultivated? - [[User:MyUserName|MyUserName]] # [[/Reflected glory/]] - What is reflected glory and what are its pros and cons? - [[User:MyUserName|MyUserName]] # [[/Religiosity and coping/]] - What is the relationship between religiosity and coping? - [[U3215326]] # [[/Resentment/]] - What is resentment, what causes it, and what are its consequences? - [[User:U3216389|U3216389]] # [[/Risk-as-feelings/]] - What is the emotional experience of risk and how does it influence decision-making and behaviour? - BenjiD'Ange # [[/Self-esteem and culture/]] - What are the cultural influences on self-esteem? - [[User:Jingru shao 0906|Jingru shao0906]] # [[/Smiling and emotion/]] - What is the relationship between smiling and emotion? - U3200902 # [[/Social media and suicide prevention/]] - How can social media be used to help prevent suicide? - [[JaimeTegan|JaimeTegan]] # [[/Sorry business/]] - What is sorry business and what role does it play in Indigenous communities in Australia? - Isaacem13 # [[/Stress control mindset/]] - What is a SCM, why does it matter, and how can it be cultivated? - [[User:MyUserName|MyUserName]] # [[/Suffering as emotion/]] - What is the emotional experience of suffering and how can people cope with suffering? - [[User:Brookewin|Brookewin]] # [[/Telemental health/]] - What are the pros and cons of TMH and what are the key ingredients for effective TMH practices? - [[User:MyUserName|MyUserName]] # [[/Topophilia/]] - What is topophilia, how does it develop, and what are the psychological impacts? - [[User:RSPMeredith|RSPMeredith]] # [[/Triumph/]] - What is triumph, what causes it, and how can it be managed? - [[User:Bill.miosge|Bill.miosge]] # [[/Unemployment and mental health/]]: What is the relationship between unemployment and mental health? - [[User:MyUserName|U3216958 - Tiarna.Wilson-Ginn]] # [[/Viewing natural scenes and emotion/]] - What is the effect of viewing natural scenes on emotion and how can this be applied? - [[User:MyUserName|MyUserName]] # [[/Wave metaphor for emotion/]] - In what respects is an ocean wave a helpful metaphor for understanding human emotions? - [[jamieepiper]] # [[/Window of tolerance/]] - What is the window of tolerance and how this concept be used? - [[User:U3223109|U3223109]] # [[/Workplace mental health training/]] - What is WMHT, what techniques are used, and what are the impacts? - [[ArtOfHappiness]] # [[/Zoom fatigue/]] - What is Zoom fatigue, what causes it, what are its consequences, and what can be done about it? - [[User:u3211603|U3211603]] ==Motivation and emotion== # [[/Financial investing, motivation, and emotion/]] - What role does motivation and emotion play in financial investing? - [[U3217287|U3217287]] # [[/Hostage negotiation, motivation, and emotion/]] - What role does motivation and emotion play in hostage negotiation? - [[User:U3213549|U3213549]] # [[/Money priming, motivation, and emotion/]] - What is the effect of money priming on motivation and emotion? - [[User:Molzaroid|Molzaroid]] # [[/Motivational dimensional model of affect/]] - What is the motivational dimensional model of affect and what are its implications? - [[User:MyUserName|MyUserName]] # [[/Napping, motivation, and emotion/]] - What are the motivational and emotional effects of napping? - [[User:MyUserName|MyUserName]] # [[/Overchoice, emotion, and motivation/]] - What are the emotional and motivational effects of overchoice? - [[User:MyUserName|MyUserName]] # [[/Patience and impatience/]] - What are the psychological causes and consequences of patience and impatience? - [[User:u3100193|u3100193]] # [[/Reward system, motivation, and emotion/]] - What role does the reward system play in motivation and emotion? - [[User:U3162201|U3162201]] [[Category:Motivation and emotion/Book/2022]] cifg5l1c8vvccppinrmvmmrdrg2obhj 2414017 2414006 2022-08-13T03:04:05Z Jdebear 2948147 /* Emotion */ wikitext text/x-wiki {{/Banner}} ==Motivation == # [[Academic help-seeking]] - What are the barriers and enablers of AHS and how can AHS be fostered? - [[User:Ibm4444|Ibm4444]] # [[/Academic self-regulation/]] - What is academic self-regulation, why does it matter, and how can it be fostered? - [[U3216563]] # [[/Actively open-minded thinking/]] - How can AOT be used to improve human performance? - [[User:MyUserName|MyUserName]] # [[/Active transport motivation/]] - What motivates use of active transport and how can people be encouraged to use it? - [[User:MyUserName|MyUserName]] # [[/Antidepressants and motivation/]] - What are the effects of popular antidepressants on motivation? - [[User:U3222363|U3222363]] # [[/Approach motivation/]] - What is approach motivation and how does it lead to behaviour? - [[User:U3189370|U3189370]] # [[/Behavioural economics and motivation/]] - What aspects of motivation theory are useful in behavioural economics? - [[User:U3141987|U3141987]] # [[/Behavioural model of health services/]] - What is the BMHS and how can it be used? - SoSilverLibby # [[/Beneficence as a psychological need/]] - What is beneficence and what are its implications as a psychological need? - [[User:MyUserName|CaitlinEmc]] # [[/Brief motivational interviewing as a health intervention/]] - How can brief motivational interviewing be used as a health intervention? - [[User:MyUserName|MyUserName]] # [[/Choice overload/]] - What is choice overload? What is the optimal amount of choice? - [[UserGeorgiaFairweather|GeorgiaFairweather]] # [[/Chunking and goal pursuit/]] - How does chunking affect goal pursuit? - GiovanniBartlett # [[/Cognitive entrenchment/]] - What is cognitive entrenchment and how can it be avoided? - [[JimmyOC1985|JimmyOC1985]] # [[/Climate change helplessness/]] - How does learned helpless impact motivation to engage in behaviours to limit climate change? - [[User:U3193000|U3193000]] # [[/Closeness communication bias/]] - What is the CCB, why does it occur, and how can it be overcome? - [[User:U3215103|U3215103]] # [[/Commitment bias/]] - What motivates escalation of commitment even it does not lead to desirably outcomes? - [[User:MyUserName|MyUserName]] # [[/Conspiracy theory motivation/]] - What motivates people to believe in conspiracy theories? - [[User:KingMob221|KingMob221]] # [[/Construal level theory/]] - What is construal level theory and how can it be applied? - [[User:MyUserName|MyUserName]] # [[/Courage motivation/]] - What is courage, what motivates courage, and how can courage be enhanced? -[[User:Hanarose123|Hanarose123]] # [[/Death drive/]] - What is the death drive and how can it be negotiated? - [[User:U3086459|U3086459]] # [[Motivation and emotion/Book/2022/Drugs-violence nexus and motivation|Drugs-violence nexus and motivation]] - What is the role of motivation in the drugs-violence nexus? - [[Atu3202070|Atu3202070]] # [[/Episodic future thinking and delay discounting/]] - What is the relationship between between EFT and DD? - [[User:MyUserName|MyUserName]] # [[/Episodic memory and planning/]] - What role does episodic memory play in planning? - [[User:MyUserName|U3246310]] # [[/Equity theory/]] - What is equity theory and how can it be applied? - [[EKS2001|EKS2001]] # [[/ERG theory/]] - What is Alderfer's ERG theory? - [[User:MyUserName|MyUserName]] # [[/Frame of reference and motivation/]] - How does frame of reference affect motivation? - [[User:MyUserName|MyUserName]] # [[/Freedom and motivation/]] - What is the effect of freedom on motivation? - [[Cedevlin9|Cedevlin9]] # [[/Fully functioning person/]] - What is a FFP and how can full functioning be developed? - [[User:Sebastian Armstrong|Sebastian Armstrong]] # [[/Functional fixedness/]] - What is functional fixedness and how can it be overcome? - [[User:U3214117|U3214117]] # [[/Functional imagery training/]] - What is FIT and how can it be applied? - [[User:Btarmstrong24|Btarmstrong24]] # [[/Gamification and work motivation/]] - How can gamification enhance work motivation? - [[U3211125|U3211125]] # [[/Giving up goals/]] - When should we give up goals and when should we persist? - [[User:MyUserName|U3161584]] # [[/Green prescription motivation/]] - What motivates green prescription compliance? - [[User:Earthxangel|Earthxangel]] # [[/Health belief model/]] - What is the HBM and how can it be used to enhance motivation for health-promoting behaviour? - [[SoSilverLibby]] # [[/Help-seeking among boys/]] - What are the barriers to help-seeking for boys and what motivates them to seek help? - [[User:BradMcGrath|BradMcGrath]] # [[/Hidden costs of reward/]] - What are the hidden costs of motivating by reward? - [[User:SLoCE|u3033296]] # [[/Hijack hypothesis of drug addiction/]] - What is the hijack hypothesis, what is the evidence, and how does it help to understand drug addiction? - [[U3218292|U3218292]] # [[/Honesty motivation/]] - What motivates honesty? - [[User:U3200859|U3200859]] # [[/Humour, leadership, and work/]] - What role does humour play in effective leadership in the workplace? - [[User:U3210264|U3210264]] # [[/IKEA effect/]] - What is the IKEA effect and how can it be applied? - [[U3216963|U]]3216963 # [[/Intertemporal choice/]] - What are intertemporal choices and how can they be effectively negotiated? - [[User:MyUserName|MyUserName]] # [[/Kindness motivation/]] - What motivates kindness? - [[User:U3205429|U3205429]] # [[/Motivational music and exercise/]] - How can music be used to help motivate exercise? - [[User:MyUserName|U3183466]] # [[/Novelty-variety as a psychological need/]] - What is novelty-variety and what are its implications as a psychological need? - [[User:MyUserName|MyUserName]] # [[/Nucleus accumbens and motivation/]] - What role does the nucleus accumbens play in motivation? - [[User:U3213250|U3213250]] # [[/Perfectionism/]] - What motivates perfectionism? Is perfectionism good or bad? How can it be managed? - [[User:AEMOR|AEMOR]] # [[/Physiological needs/]] - How do human's physiological needs affect motivation? - [[U3203655]] # [[/Protection motivation theory and COVID-19/]] - How does PMT apply to managing COVID-19? - [[User:U3200956|U3200956]] # [[/Relative deprivation and motivation/]] - What is the effect of relative deprivation on motivation? - [[User:U3191574 (PHP)|U3191574 (PHP)]] # [[/Retrospective regret/]] - What is the motivational role of retrospective regret? - [[User:Will-U3214082|Will-U3214082]] # [[/Revenge motivation/]] - What motivates revenge and how does it affect us? - [[User:U3216654|U3216654]] # [[/Self-efficacy and academic achievement/]] - What role does self-efficacy play in academic achievement? - [[User:U943292|U943292]]a # [[/Self-efficacy and achievement/]] - What role does self-efficacy play in achievement outcomes? - [[User:U3216513mt|U3216513mt]] # [[/Sexual harassment at work motivation/]] - What motivates sexual harassment at work and what can be done about it? - [[User:U3037979|U3037979]] # [[/Signature strengths/]] - What are signature strengths and how can they be applied? - [[User:MyUserName|MyUserName]] # [[/Social cure/]] - What is the social cure and how can it be applied? - [[User:U3215976|U3215976]] # [[/System justification theory/]] - What is SJT, how does it affect our lives, and what can be done about it? - [[User:MyUserName|MyUserName]] # [[/Stretch goals/]] - What are stretch goals? Do they work? - [[User:MyUserName|MyUserName]] # [[/Sublimation/]] - What is sublimation and how can it be fostered? - [[User:MyUserName|MyUserName]] # [[/Survival needs and motivation/]] - What are survival needs and how do they influence motivation? - [[User:U3148161|U3148161]] # [[/Task initiation/]] - What are the challenges with task initiation and how to get get started? - [[User:MyUserName|U3210006]] # [[/Theoretical domains framework/]] - What is the TDF and how can be used to guide behaviour change? - [[User:MyUserName|MyUserName]] # [[/Time and motivation/]] - What is the effect of time on motivation? - [[User:Lturner2311|Lturner2311]] # [[/Time management/]] - How can one's time be managed effectively? - [[User:CNK.20|CNK.20]] # [[/To-do lists/]] - Are to-do lists a good idea? What are their pros and cons? How can they be used effectively? - [[User:U3207458|U3207458]] # [[/Uncertainty avoidance/]] - What is uncertainty avoidance, why does it occur, and what are its consequences? - [[User:Franklin Brightt|Franklin Brightt]] # [[/Urgency bias and productivity/]] - What is the impact of urgency bias on productivity and what can be done about it? - U3055143 # [[/Vocational identity/]] - What is vocational identity and how does it develop? - [[User:MyUserName|MyUserName]] # [[/Volunteer tourism motivation/]] - What motivates volunteer tourism? - [[User:U962051|U962051]] # [[/Wanting and liking/]] - What are the similarities and differences between wanting and liking, and what are the implications? - [[U3201643]] # [[/Work breaks, well-being, and productivity/]] - How do work breaks affect well-being and productivity? - [[User:MyUserName|U3215603]] # [[/Work and flow/]] - What characteristics of work can produce flow and how can flow at work be fostered? - [[User:U3213441|U3213441]] ==Emotion== # [[/Animal emotion/]] - What is the emotional experience of animals? - [[U3216502]] # [[/Attributions and emotion/]] - How do attributions affect emotion? - [[User:MyUserName|MyUserName]] # [[/Autonomous sensory meridian response and emotion/]] - What emotions are involved in ASMR experiences and why do they occur? - [[User:U3186959|U3186959]] # [[/Benzodiazepines and emotion/]] - What are the effects of benzodiazepines on emotion? - [[User:FulaAjeo22|FulaAjeo22]] # [[/Bewilderment/]] - What is bewilderment and how can it be dealt with? - SunandaUC # [[/Burnout/]] - What is burnout and how can be it be managed and prevented? - [[U3202788]] # [[/Cognitive dissonance reduction/]] - What strategies do people use to reduce cognitive dissonance and how effective are they? - [[User:Tatjurate|Tatjurate]] # [[/Colonisation and emotion in Australia/]] - What are the emotional responses to colonisation in Australia? - [[User:Micabaker1|Micabaker1]] # [[/Compassion/]] - What is compassion, what are its pros and cons, and how can it be fostered? - u3203545 # [[/Connection to country and well-being/]] - What is the relationship between connection to country and well-being? - [[User:MyUserName|MyUserName]] # [[/Contempt/]] - What is contempt, what causes it, and how can it be managed? - [[User:MyUserName|u3219905]] # [[/Core emotions/]] - What are the core emotions and what is their function? U3203140 # [[/Creative arts and trauma/]] - How can creative arts help in dealing with trauma? - [[MyUserName|SashaBrooksby]] # [[/Cultural influences on shame, guilt, and pride/]] - How does culture influence shame, guilt, and pride? - [[User:Tamika Afeaki|Tamika Afeaki]] # [[/Default mode network and the self/]] - What is the relationship between the DMN and the self? - [[User:MyUserName|MyUserName]] # [[/Difficult conversations and emotion/]] - What communication and emotional skills are needed to successfully negotiate difficult conversations? - [[User:u3158968|u3158968]] # [[/Disappointment/]] - What is disappointment, what causes disappointment, and how can disappointment be managed? - [[User:U3216256|U3216256]] # [[/DMT and spirituality/]] - How can DMT facilitate spiritual experiences? - [[DenniseSoleymani]] # [[/Durability bias in affective forecasting/]] - What role does durability bias play in affective forecasting? - [[User:MyUserName|MyUserName]] # [[/Ecological grief/]] - What is ecological grief and what can be done about it? - [[User:Brewerjr|Brewerjr]] # [[/Ecopsychology and stress/]] - How can ecopsychology help to explain and deal with stress? - [[User:Jdebear|MyUserName]] # [[/Embarrassment/]] - What is embarrassment, what causes it, and how can it be managed? - u3190353 # [[/Emotional intelligence training/]] - How can emotional intelligence be trained? - Eimilerous22 # [[/Emotion knowledge/]] - What is emotion knowledge and how can it be developed? - [[User:GabbieUC|GabbieUC]] # [[/Emotion across the lifespan/]] - How does emotion develop across the lifespan? - u3230861 # [[/Endocannabinoid system and emotion/]] - What is the role of the endocannabinoid system in emotion? - [[User:RWilliams12|Rwilliams12]] # [[/Environmental grief/]] - What is eco-grief, its causes and consequences, and what can be done? - [[User:Gabrielle Eagling|Gabrielle Eagling]] # [[/Exercise and endocannabinoids/]] - What is the relationship between exercise and the endocannabinoid system? - [[User:MyUserName|MyUserName]] # [[/Expressive suppression and emotion regulation/]] - What is the role of expressive suppression in emotion regulation? - [[U3131472]] # [[/Fairness and emotion/]] - What is the relation between fairness and emotion? - U3246554 # [[/Fatigue and emotion/]] - What is the effect of fatigue on emotion and what can be done about it? - [[User:Lewis.Kusk|Lewis.Kusk]] # [[/Fear/]] - What is fear, what causes it, and how can it be managed? - [[User:Icantchooseone|Icantchooseone]] # [[/Fear of working out/]] - What is FOWO and how can it be overcome? - [[User:MyUserName|MyUserName]] # [[/Fundamental attribution error and emotion/]] - What is the relationship between the FAE and emotion? - [[User:MyUserName|MyUserName]] # [[/Gratitude and subjective wellbeing/]] - What is the relationship between gratitude and subjective wellbeing? - [[User:MyUserName|MyUserName]] # [[/Gloatrage/]] - What is gloatrage, what causes it, and what are its consequences? - [[User:MyUserName|MyUserName]] # [[/Heart rate variability and emotion regulation/]] - What is the relationship between HRV and emotion regulation? - [[User:MyUserName|MyUserName]] # [[/Hedonic adaptation prevention model/]] - What is the HAP model and how can it be applied? - [[User:Lyndel Lemon|Lyndel Lemon]] # [[/Humility/]] - What is humility, what causes it, and is it desirable? - [[User:MyUserName|MyUserName]] # [[/Hypomania and emotion/]] - What are the emotional characteristics of hypomania? - [[User:Alec.cortez|Alec.cortez]] # [[/Impact bias/]] - What is impact bias, what causes it, what are its consequences, and how can it be avoided? - [[User:MyUserName|MyUserName]] # [[Indigenous Australian emotionality]] - In what ways is emotionality experienced by Indigenous Australian people? - [[User:U3189442 - K.Ryan|U3189442 - K.Ryan]] # [[/Indigenous Australian mindfulness/]] - How has Indigenous Australian culture traditionally conceived of, and practiced, mindfulness? - [[User:MyUserName|MyUserName]] # [[/Inspiration/]] - What is inspiration, what causes it, what are its consequences, and how can it be fostered? - [[User:MyUserName|u3227354]] # [[/Insular cortex and emotion/]] - What role does the insular cortex play in emotion? - [[User:U3190094|U3190094]] # [[/Interoception and emotion/]] - What is the relationship between interoception and emotion? - u3203265 # [[/Kama muta/]] - What is kama muta, what are its effects, and how can it be fostered? - [[User:U3183521|U3183521]] # [[/Linguistic relativism and emotion/]] - What is the role of linguistic relativism in emotion? - [[User:U3119310|U3119310]] # [[/Menstrual cycle mood disorders/]] - What causes menstrual cycle mood disorders and how can they be managed? - [[User:MyUserName|U3217109]] # [[/Mindfulness and creativity/]] - How can mindfulness enhance creativity? - [[CaityDcr1603]] # [[/Mindful self-care/]] - What is mindful self-care, why does it matter, and how can it be developed? - [[User:clairelogan|clairelogan]] # [[/Mixed emotions/]] - What are mixed emotions, what causes them, and how can they be managed? - [[User:MyUserName|u3210490]] # [[/Mudita/]] - What is mudita and how can it be developed? - [[User:MyUserName|MyUserName]] # [[/Natural disasters and emotion/]] - How do people respond emotionally to natural disasters and how can they be supported? -[[User:U3148366_Chris|U3148366_Chris]] # [[/Nature therapy/]] - What is nature therapy and how can it be applied? - Ana028 # [[/Narcissism and emotion/]] - What is the relationship between narcissism and emotion? - [[User:A Super Villain|A Super Villain]] # [[/Narrative therapy and emotion/]] - What is the role of emotion in narrative therapy? - [[User:MyUserName|MyUserName]] # [[/Needle fear/]] - How does needle fear develop, what are its consequences, and what can be done about it? - [[User:U3166273|U3166273]] # [[/Positivity ratio/]] - What is the positivity ratio and what are its implications? - [[User:MyUserName|MyUserName]] # [[/Post-traumatic stress disorder and emotion/]] - What is the effect of PTSD on emotion? - [[User:JorjaFive|JorjaFive]] # [[/Psychological distress/]] - What is PD, what are the main types, and how can they be managed? - [[User:U3190773|U3190773]] # [[/Psychological trauma/]] - What causes psychological trauma, what are the consequences, and how can people recover from psychological trauma? - [[User:U3210431|U3210431]] # [[/Psilocybin assisted psychotherapy/]] - How can psilocybin be used to assist psychotherapy? - [[User:U3083720|U3083720]] # [[/Rational compassion/]] - What is rational compassion and how can it be cultivated? - [[User:MyUserName|MyUserName]] # [[/Reflected glory/]] - What is reflected glory and what are its pros and cons? - [[User:MyUserName|MyUserName]] # [[/Religiosity and coping/]] - What is the relationship between religiosity and coping? - [[U3215326]] # [[/Resentment/]] - What is resentment, what causes it, and what are its consequences? - [[User:U3216389|U3216389]] # [[/Risk-as-feelings/]] - What is the emotional experience of risk and how does it influence decision-making and behaviour? - BenjiD'Ange # [[/Self-esteem and culture/]] - What are the cultural influences on self-esteem? - [[User:Jingru shao 0906|Jingru shao0906]] # [[/Smiling and emotion/]] - What is the relationship between smiling and emotion? - U3200902 # [[/Social media and suicide prevention/]] - How can social media be used to help prevent suicide? - [[JaimeTegan|JaimeTegan]] # [[/Sorry business/]] - What is sorry business and what role does it play in Indigenous communities in Australia? - Isaacem13 # [[/Stress control mindset/]] - What is a SCM, why does it matter, and how can it be cultivated? - [[User:MyUserName|MyUserName]] # [[/Suffering as emotion/]] - What is the emotional experience of suffering and how can people cope with suffering? - [[User:Brookewin|Brookewin]] # [[/Telemental health/]] - What are the pros and cons of TMH and what are the key ingredients for effective TMH practices? - [[User:MyUserName|MyUserName]] # [[/Topophilia/]] - What is topophilia, how does it develop, and what are the psychological impacts? - [[User:RSPMeredith|RSPMeredith]] # [[/Triumph/]] - What is triumph, what causes it, and how can it be managed? - [[User:Bill.miosge|Bill.miosge]] # [[/Unemployment and mental health/]]: What is the relationship between unemployment and mental health? - [[User:MyUserName|U3216958 - Tiarna.Wilson-Ginn]] # [[/Viewing natural scenes and emotion/]] - What is the effect of viewing natural scenes on emotion and how can this be applied? - [[User:MyUserName|MyUserName]] # [[/Wave metaphor for emotion/]] - In what respects is an ocean wave a helpful metaphor for understanding human emotions? - [[jamieepiper]] # [[/Window of tolerance/]] - What is the window of tolerance and how this concept be used? - [[User:U3223109|U3223109]] # [[/Workplace mental health training/]] - What is WMHT, what techniques are used, and what are the impacts? - [[ArtOfHappiness]] # [[/Zoom fatigue/]] - What is Zoom fatigue, what causes it, what are its consequences, and what can be done about it? - [[User:u3211603|U3211603]] ==Motivation and emotion== # [[/Financial investing, motivation, and emotion/]] - What role does motivation and emotion play in financial investing? - [[U3217287|U3217287]] # [[/Hostage negotiation, motivation, and emotion/]] - What role does motivation and emotion play in hostage negotiation? - [[User:U3213549|U3213549]] # [[/Money priming, motivation, and emotion/]] - What is the effect of money priming on motivation and emotion? - [[User:Molzaroid|Molzaroid]] # [[/Motivational dimensional model of affect/]] - What is the motivational dimensional model of affect and what are its implications? - [[User:MyUserName|MyUserName]] # [[/Napping, motivation, and emotion/]] - What are the motivational and emotional effects of napping? - [[User:MyUserName|MyUserName]] # [[/Overchoice, emotion, and motivation/]] - What are the emotional and motivational effects of overchoice? - [[User:MyUserName|MyUserName]] # [[/Patience and impatience/]] - What are the psychological causes and consequences of patience and impatience? - [[User:u3100193|u3100193]] # [[/Reward system, motivation, and emotion/]] - What role does the reward system play in motivation and emotion? - [[User:U3162201|U3162201]] [[Category:Motivation and emotion/Book/2022]] 03aq9nzpepz68qf9ptm9htxwmeb5h1i 2414019 2414017 2022-08-13T03:10:18Z Jdebear 2948147 /* Emotion */ wikitext text/x-wiki {{/Banner}} ==Motivation == # [[Academic help-seeking]] - What are the barriers and enablers of AHS and how can AHS be fostered? - [[User:Ibm4444|Ibm4444]] # [[/Academic self-regulation/]] - What is academic self-regulation, why does it matter, and how can it be fostered? - [[U3216563]] # [[/Actively open-minded thinking/]] - How can AOT be used to improve human performance? - [[User:MyUserName|MyUserName]] # [[/Active transport motivation/]] - What motivates use of active transport and how can people be encouraged to use it? - [[User:MyUserName|MyUserName]] # [[/Antidepressants and motivation/]] - What are the effects of popular antidepressants on motivation? - [[User:U3222363|U3222363]] # [[/Approach motivation/]] - What is approach motivation and how does it lead to behaviour? - [[User:U3189370|U3189370]] # [[/Behavioural economics and motivation/]] - What aspects of motivation theory are useful in behavioural economics? - [[User:U3141987|U3141987]] # [[/Behavioural model of health services/]] - What is the BMHS and how can it be used? - SoSilverLibby # [[/Beneficence as a psychological need/]] - What is beneficence and what are its implications as a psychological need? - [[User:MyUserName|CaitlinEmc]] # [[/Brief motivational interviewing as a health intervention/]] - How can brief motivational interviewing be used as a health intervention? - [[User:MyUserName|MyUserName]] # [[/Choice overload/]] - What is choice overload? What is the optimal amount of choice? - [[UserGeorgiaFairweather|GeorgiaFairweather]] # [[/Chunking and goal pursuit/]] - How does chunking affect goal pursuit? - GiovanniBartlett # [[/Cognitive entrenchment/]] - What is cognitive entrenchment and how can it be avoided? - [[JimmyOC1985|JimmyOC1985]] # [[/Climate change helplessness/]] - How does learned helpless impact motivation to engage in behaviours to limit climate change? - [[User:U3193000|U3193000]] # [[/Closeness communication bias/]] - What is the CCB, why does it occur, and how can it be overcome? - [[User:U3215103|U3215103]] # [[/Commitment bias/]] - What motivates escalation of commitment even it does not lead to desirably outcomes? - [[User:MyUserName|MyUserName]] # [[/Conspiracy theory motivation/]] - What motivates people to believe in conspiracy theories? - [[User:KingMob221|KingMob221]] # [[/Construal level theory/]] - What is construal level theory and how can it be applied? - [[User:MyUserName|MyUserName]] # [[/Courage motivation/]] - What is courage, what motivates courage, and how can courage be enhanced? -[[User:Hanarose123|Hanarose123]] # [[/Death drive/]] - What is the death drive and how can it be negotiated? - [[User:U3086459|U3086459]] # [[Motivation and emotion/Book/2022/Drugs-violence nexus and motivation|Drugs-violence nexus and motivation]] - What is the role of motivation in the drugs-violence nexus? - [[Atu3202070|Atu3202070]] # [[/Episodic future thinking and delay discounting/]] - What is the relationship between between EFT and DD? - [[User:MyUserName|MyUserName]] # [[/Episodic memory and planning/]] - What role does episodic memory play in planning? - [[User:MyUserName|U3246310]] # [[/Equity theory/]] - What is equity theory and how can it be applied? - [[EKS2001|EKS2001]] # [[/ERG theory/]] - What is Alderfer's ERG theory? - [[User:MyUserName|MyUserName]] # [[/Frame of reference and motivation/]] - How does frame of reference affect motivation? - [[User:MyUserName|MyUserName]] # [[/Freedom and motivation/]] - What is the effect of freedom on motivation? - [[Cedevlin9|Cedevlin9]] # [[/Fully functioning person/]] - What is a FFP and how can full functioning be developed? - [[User:Sebastian Armstrong|Sebastian Armstrong]] # [[/Functional fixedness/]] - What is functional fixedness and how can it be overcome? - [[User:U3214117|U3214117]] # [[/Functional imagery training/]] - What is FIT and how can it be applied? - [[User:Btarmstrong24|Btarmstrong24]] # [[/Gamification and work motivation/]] - How can gamification enhance work motivation? - [[U3211125|U3211125]] # [[/Giving up goals/]] - When should we give up goals and when should we persist? - [[User:MyUserName|U3161584]] # [[/Green prescription motivation/]] - What motivates green prescription compliance? - [[User:Earthxangel|Earthxangel]] # [[/Health belief model/]] - What is the HBM and how can it be used to enhance motivation for health-promoting behaviour? - [[SoSilverLibby]] # [[/Help-seeking among boys/]] - What are the barriers to help-seeking for boys and what motivates them to seek help? - [[User:BradMcGrath|BradMcGrath]] # [[/Hidden costs of reward/]] - What are the hidden costs of motivating by reward? - [[User:SLoCE|u3033296]] # [[/Hijack hypothesis of drug addiction/]] - What is the hijack hypothesis, what is the evidence, and how does it help to understand drug addiction? - [[U3218292|U3218292]] # [[/Honesty motivation/]] - What motivates honesty? - [[User:U3200859|U3200859]] # [[/Humour, leadership, and work/]] - What role does humour play in effective leadership in the workplace? - [[User:U3210264|U3210264]] # [[/IKEA effect/]] - What is the IKEA effect and how can it be applied? - [[U3216963|U]]3216963 # [[/Intertemporal choice/]] - What are intertemporal choices and how can they be effectively negotiated? - [[User:MyUserName|MyUserName]] # [[/Kindness motivation/]] - What motivates kindness? - [[User:U3205429|U3205429]] # [[/Motivational music and exercise/]] - How can music be used to help motivate exercise? - [[User:MyUserName|U3183466]] # [[/Novelty-variety as a psychological need/]] - What is novelty-variety and what are its implications as a psychological need? - [[User:MyUserName|MyUserName]] # [[/Nucleus accumbens and motivation/]] - What role does the nucleus accumbens play in motivation? - [[User:U3213250|U3213250]] # [[/Perfectionism/]] - What motivates perfectionism? Is perfectionism good or bad? How can it be managed? - [[User:AEMOR|AEMOR]] # [[/Physiological needs/]] - How do human's physiological needs affect motivation? - [[U3203655]] # [[/Protection motivation theory and COVID-19/]] - How does PMT apply to managing COVID-19? - [[User:U3200956|U3200956]] # [[/Relative deprivation and motivation/]] - What is the effect of relative deprivation on motivation? - [[User:U3191574 (PHP)|U3191574 (PHP)]] # [[/Retrospective regret/]] - What is the motivational role of retrospective regret? - [[User:Will-U3214082|Will-U3214082]] # [[/Revenge motivation/]] - What motivates revenge and how does it affect us? - [[User:U3216654|U3216654]] # [[/Self-efficacy and academic achievement/]] - What role does self-efficacy play in academic achievement? - [[User:U943292|U943292]]a # [[/Self-efficacy and achievement/]] - What role does self-efficacy play in achievement outcomes? - [[User:U3216513mt|U3216513mt]] # [[/Sexual harassment at work motivation/]] - What motivates sexual harassment at work and what can be done about it? - [[User:U3037979|U3037979]] # [[/Signature strengths/]] - What are signature strengths and how can they be applied? - [[User:MyUserName|MyUserName]] # [[/Social cure/]] - What is the social cure and how can it be applied? - [[User:U3215976|U3215976]] # [[/System justification theory/]] - What is SJT, how does it affect our lives, and what can be done about it? - [[User:MyUserName|MyUserName]] # [[/Stretch goals/]] - What are stretch goals? Do they work? - [[User:MyUserName|MyUserName]] # [[/Sublimation/]] - What is sublimation and how can it be fostered? - [[User:MyUserName|MyUserName]] # [[/Survival needs and motivation/]] - What are survival needs and how do they influence motivation? - [[User:U3148161|U3148161]] # [[/Task initiation/]] - What are the challenges with task initiation and how to get get started? - [[User:MyUserName|U3210006]] # [[/Theoretical domains framework/]] - What is the TDF and how can be used to guide behaviour change? - [[User:MyUserName|MyUserName]] # [[/Time and motivation/]] - What is the effect of time on motivation? - [[User:Lturner2311|Lturner2311]] # [[/Time management/]] - How can one's time be managed effectively? - [[User:CNK.20|CNK.20]] # [[/To-do lists/]] - Are to-do lists a good idea? What are their pros and cons? How can they be used effectively? - [[User:U3207458|U3207458]] # [[/Uncertainty avoidance/]] - What is uncertainty avoidance, why does it occur, and what are its consequences? - [[User:Franklin Brightt|Franklin Brightt]] # [[/Urgency bias and productivity/]] - What is the impact of urgency bias on productivity and what can be done about it? - U3055143 # [[/Vocational identity/]] - What is vocational identity and how does it develop? - [[User:MyUserName|MyUserName]] # [[/Volunteer tourism motivation/]] - What motivates volunteer tourism? - [[User:U962051|U962051]] # [[/Wanting and liking/]] - What are the similarities and differences between wanting and liking, and what are the implications? - [[U3201643]] # [[/Work breaks, well-being, and productivity/]] - How do work breaks affect well-being and productivity? - [[User:MyUserName|U3215603]] # [[/Work and flow/]] - What characteristics of work can produce flow and how can flow at work be fostered? - [[User:U3213441|U3213441]] ==Emotion== # [[/Animal emotion/]] - What is the emotional experience of animals? - [[U3216502]] # [[/Attributions and emotion/]] - How do attributions affect emotion? - [[User:MyUserName|MyUserName]] # [[/Autonomous sensory meridian response and emotion/]] - What emotions are involved in ASMR experiences and why do they occur? - [[User:U3186959|U3186959]] # [[/Benzodiazepines and emotion/]] - What are the effects of benzodiazepines on emotion? - [[User:FulaAjeo22|FulaAjeo22]] # [[/Bewilderment/]] - What is bewilderment and how can it be dealt with? - SunandaUC # [[/Burnout/]] - What is burnout and how can be it be managed and prevented? - [[U3202788]] # [[/Cognitive dissonance reduction/]] - What strategies do people use to reduce cognitive dissonance and how effective are they? - [[User:Tatjurate|Tatjurate]] # [[/Colonisation and emotion in Australia/]] - What are the emotional responses to colonisation in Australia? - [[User:Micabaker1|Micabaker1]] # [[/Compassion/]] - What is compassion, what are its pros and cons, and how can it be fostered? - u3203545 # [[/Connection to country and well-being/]] - What is the relationship between connection to country and well-being? - [[User:MyUserName|MyUserName]] # [[/Contempt/]] - What is contempt, what causes it, and how can it be managed? - [[User:MyUserName|u3219905]] # [[/Core emotions/]] - What are the core emotions and what is their function? U3203140 # [[/Creative arts and trauma/]] - How can creative arts help in dealing with trauma? - [[MyUserName|SashaBrooksby]] # [[/Cultural influences on shame, guilt, and pride/]] - How does culture influence shame, guilt, and pride? - [[User:Tamika Afeaki|Tamika Afeaki]] # [[/Default mode network and the self/]] - What is the relationship between the DMN and the self? - [[User:MyUserName|MyUserName]] # [[/Difficult conversations and emotion/]] - What communication and emotional skills are needed to successfully negotiate difficult conversations? - [[User:u3158968|u3158968]] # [[/Disappointment/]] - What is disappointment, what causes disappointment, and how can disappointment be managed? - [[User:U3216256|U3216256]] # [[/DMT and spirituality/]] - How can DMT facilitate spiritual experiences? - [[DenniseSoleymani]] # [[/Durability bias in affective forecasting/]] - What role does durability bias play in affective forecasting? - [[User:MyUserName|MyUserName]] # [[/Ecological grief/]] - What is ecological grief and what can be done about it? - [[User:Brewerjr|Brewerjr]] # [[/Ecopsychology and stress/]] - How can ecopsychology help to explain and deal with stress? - [[User:Jdebear|Jdebear]] # [[/Embarrassment/]] - What is embarrassment, what causes it, and how can it be managed? - u3190353 # [[/Emotional intelligence training/]] - How can emotional intelligence be trained? - Eimilerous22 # [[/Emotion knowledge/]] - What is emotion knowledge and how can it be developed? - [[User:GabbieUC|GabbieUC]] # [[/Emotion across the lifespan/]] - How does emotion develop across the lifespan? - u3230861 # [[/Endocannabinoid system and emotion/]] - What is the role of the endocannabinoid system in emotion? - [[User:RWilliams12|Rwilliams12]] # [[/Environmental grief/]] - What is eco-grief, its causes and consequences, and what can be done? - [[User:Gabrielle Eagling|Gabrielle Eagling]] # [[/Exercise and endocannabinoids/]] - What is the relationship between exercise and the endocannabinoid system? - [[User:MyUserName|MyUserName]] # [[/Expressive suppression and emotion regulation/]] - What is the role of expressive suppression in emotion regulation? - [[U3131472]] # [[/Fairness and emotion/]] - What is the relation between fairness and emotion? - U3246554 # [[/Fatigue and emotion/]] - What is the effect of fatigue on emotion and what can be done about it? - [[User:Lewis.Kusk|Lewis.Kusk]] # [[/Fear/]] - What is fear, what causes it, and how can it be managed? - [[User:Icantchooseone|Icantchooseone]] # [[/Fear of working out/]] - What is FOWO and how can it be overcome? - [[User:MyUserName|MyUserName]] # [[/Fundamental attribution error and emotion/]] - What is the relationship between the FAE and emotion? - [[User:MyUserName|MyUserName]] # [[/Gratitude and subjective wellbeing/]] - What is the relationship between gratitude and subjective wellbeing? - [[User:MyUserName|MyUserName]] # [[/Gloatrage/]] - What is gloatrage, what causes it, and what are its consequences? - [[User:MyUserName|MyUserName]] # [[/Heart rate variability and emotion regulation/]] - What is the relationship between HRV and emotion regulation? - [[User:MyUserName|MyUserName]] # [[/Hedonic adaptation prevention model/]] - What is the HAP model and how can it be applied? - [[User:Lyndel Lemon|Lyndel Lemon]] # [[/Humility/]] - What is humility, what causes it, and is it desirable? - [[User:MyUserName|MyUserName]] # [[/Hypomania and emotion/]] - What are the emotional characteristics of hypomania? - [[User:Alec.cortez|Alec.cortez]] # [[/Impact bias/]] - What is impact bias, what causes it, what are its consequences, and how can it be avoided? - [[User:MyUserName|MyUserName]] # [[Indigenous Australian emotionality]] - In what ways is emotionality experienced by Indigenous Australian people? - [[User:U3189442 - K.Ryan|U3189442 - K.Ryan]] # [[/Indigenous Australian mindfulness/]] - How has Indigenous Australian culture traditionally conceived of, and practiced, mindfulness? - [[User:MyUserName|MyUserName]] # [[/Inspiration/]] - What is inspiration, what causes it, what are its consequences, and how can it be fostered? - [[User:MyUserName|u3227354]] # [[/Insular cortex and emotion/]] - What role does the insular cortex play in emotion? - [[User:U3190094|U3190094]] # [[/Interoception and emotion/]] - What is the relationship between interoception and emotion? - u3203265 # [[/Kama muta/]] - What is kama muta, what are its effects, and how can it be fostered? - [[User:U3183521|U3183521]] # [[/Linguistic relativism and emotion/]] - What is the role of linguistic relativism in emotion? - [[User:U3119310|U3119310]] # [[/Menstrual cycle mood disorders/]] - What causes menstrual cycle mood disorders and how can they be managed? - [[User:MyUserName|U3217109]] # [[/Mindfulness and creativity/]] - How can mindfulness enhance creativity? - [[CaityDcr1603]] # [[/Mindful self-care/]] - What is mindful self-care, why does it matter, and how can it be developed? - [[User:clairelogan|clairelogan]] # [[/Mixed emotions/]] - What are mixed emotions, what causes them, and how can they be managed? - [[User:MyUserName|u3210490]] # [[/Mudita/]] - What is mudita and how can it be developed? - [[User:MyUserName|MyUserName]] # [[/Natural disasters and emotion/]] - How do people respond emotionally to natural disasters and how can they be supported? -[[User:U3148366_Chris|U3148366_Chris]] # [[/Nature therapy/]] - What is nature therapy and how can it be applied? - Ana028 # [[/Narcissism and emotion/]] - What is the relationship between narcissism and emotion? - [[User:A Super Villain|A Super Villain]] # [[/Narrative therapy and emotion/]] - What is the role of emotion in narrative therapy? - [[User:MyUserName|MyUserName]] # [[/Needle fear/]] - How does needle fear develop, what are its consequences, and what can be done about it? - [[User:U3166273|U3166273]] # [[/Positivity ratio/]] - What is the positivity ratio and what are its implications? - [[User:MyUserName|MyUserName]] # [[/Post-traumatic stress disorder and emotion/]] - What is the effect of PTSD on emotion? - [[User:JorjaFive|JorjaFive]] # [[/Psychological distress/]] - What is PD, what are the main types, and how can they be managed? - [[User:U3190773|U3190773]] # [[/Psychological trauma/]] - What causes psychological trauma, what are the consequences, and how can people recover from psychological trauma? - [[User:U3210431|U3210431]] # [[/Psilocybin assisted psychotherapy/]] - How can psilocybin be used to assist psychotherapy? - [[User:U3083720|U3083720]] # [[/Rational compassion/]] - What is rational compassion and how can it be cultivated? - [[User:MyUserName|MyUserName]] # [[/Reflected glory/]] - What is reflected glory and what are its pros and cons? - [[User:MyUserName|MyUserName]] # [[/Religiosity and coping/]] - What is the relationship between religiosity and coping? - [[U3215326]] # [[/Resentment/]] - What is resentment, what causes it, and what are its consequences? - [[User:U3216389|U3216389]] # [[/Risk-as-feelings/]] - What is the emotional experience of risk and how does it influence decision-making and behaviour? - BenjiD'Ange # [[/Self-esteem and culture/]] - What are the cultural influences on self-esteem? - [[User:Jingru shao 0906|Jingru shao0906]] # [[/Smiling and emotion/]] - What is the relationship between smiling and emotion? - U3200902 # [[/Social media and suicide prevention/]] - How can social media be used to help prevent suicide? - [[JaimeTegan|JaimeTegan]] # [[/Sorry business/]] - What is sorry business and what role does it play in Indigenous communities in Australia? - Isaacem13 # [[/Stress control mindset/]] - What is a SCM, why does it matter, and how can it be cultivated? - [[User:MyUserName|MyUserName]] # [[/Suffering as emotion/]] - What is the emotional experience of suffering and how can people cope with suffering? - [[User:Brookewin|Brookewin]] # [[/Telemental health/]] - What are the pros and cons of TMH and what are the key ingredients for effective TMH practices? - [[User:MyUserName|MyUserName]] # [[/Topophilia/]] - What is topophilia, how does it develop, and what are the psychological impacts? - [[User:RSPMeredith|RSPMeredith]] # [[/Triumph/]] - What is triumph, what causes it, and how can it be managed? - [[User:Bill.miosge|Bill.miosge]] # [[/Unemployment and mental health/]]: What is the relationship between unemployment and mental health? - [[User:MyUserName|U3216958 - Tiarna.Wilson-Ginn]] # [[/Viewing natural scenes and emotion/]] - What is the effect of viewing natural scenes on emotion and how can this be applied? - [[User:MyUserName|MyUserName]] # [[/Wave metaphor for emotion/]] - In what respects is an ocean wave a helpful metaphor for understanding human emotions? - [[jamieepiper]] # [[/Window of tolerance/]] - What is the window of tolerance and how this concept be used? - [[User:U3223109|U3223109]] # [[/Workplace mental health training/]] - What is WMHT, what techniques are used, and what are the impacts? - [[ArtOfHappiness]] # [[/Zoom fatigue/]] - What is Zoom fatigue, what causes it, what are its consequences, and what can be done about it? - [[User:u3211603|U3211603]] ==Motivation and emotion== # [[/Financial investing, motivation, and emotion/]] - What role does motivation and emotion play in financial investing? - [[U3217287|U3217287]] # [[/Hostage negotiation, motivation, and emotion/]] - What role does motivation and emotion play in hostage negotiation? - [[User:U3213549|U3213549]] # [[/Money priming, motivation, and emotion/]] - What is the effect of money priming on motivation and emotion? - [[User:Molzaroid|Molzaroid]] # [[/Motivational dimensional model of affect/]] - What is the motivational dimensional model of affect and what are its implications? - [[User:MyUserName|MyUserName]] # [[/Napping, motivation, and emotion/]] - What are the motivational and emotional effects of napping? - [[User:MyUserName|MyUserName]] # [[/Overchoice, emotion, and motivation/]] - What are the emotional and motivational effects of overchoice? - [[User:MyUserName|MyUserName]] # [[/Patience and impatience/]] - What are the psychological causes and consequences of patience and impatience? - [[User:u3100193|u3100193]] # [[/Reward system, motivation, and emotion/]] - What role does the reward system play in motivation and emotion? - [[User:U3162201|U3162201]] [[Category:Motivation and emotion/Book/2022]] bpvmcuel8wsgl2mpvb89rkv7qad0ccv 3 281823 2414016 2412314 2022-08-13T01:42:08Z Atcovi 276019 /* Practice day #2 Notes (8/5/2022) */ wikitext text/x-wiki == Notes/Flashcards == <strike>https://quizlet.com/403334255/german-verbs-flash-cards/ —[[User:Atcovi|Atcovi]] [[User talk:Atcovi|(Talk]] - [[Special:Contributions/Atcovi|Contribs)]] 02:33, 17 February 2022 (UTC)</strike> ===German Verbs Flashcards=== :https://quizlet.com/148741719/german-verbs-flash-cards/ - a lot better! EDIT: This set of flashcards is aimed at learning general German verbs.—[[User:Atcovi|Atcovi]] [[User talk:Atcovi|(Talk]] - [[Special:Contributions/Atcovi|Contribs)]] 00:41, 18 February 2022 (UTC) == Practice == * ''(d/a)'' '''hängen''' (where is this thing hanging?/where are you hanging this?) - to hang * ''(a)'' '''legen''' (where are you hanging this?) - to place * ''(d)'' '''liegen''' (where is this thing hanging?) - to lie (near) * ''(a)'' '''setzen''' (where is this thing hanging?) - to set * ''(d)'' '''sitzen''' (where are you hanging this?) - to sit * ''(d)'' '''stehen''' (where is this thing hanging?) - to stand * ''(a)'' '''stellen''' (where are you hanging this?) - to place ------------------------------------------------------------------------------------------------------------------------------------------- * Ich '''weiss''' nicht, wo er wohnt (in relation to someone's address: an undisputed fact) * '''Wissen''' Sie, wie spät es ist? (in relation to the time of someone's lateness: an undisputed fact) * '''Kennst''' er mich denn nicht? (familiar with someone) * Woher '''weisst''' du das denn? (in relation to someone's previous location/no specific place or person specified: an undisputed fact) * Dein Vater '''kennt''' die Stadt bestimmt gut (in relation to a place or someone: you're not 100% familiar with it) * Leider '''weiss''' ich die Telefonnummer nicht auswendig (in relation to someone's telephone number: an undisputed fact) ------------------------------------------------------------------------------------------------------------------------------------------- * Das Restaurant is neben '''einer''' Kirche. * Mein Bruder fährt sein Auto in '''die''' Garage. * Das Buch liegt auf '''dem''' Bett. * Was trägst du unter '''deinem''' Pullover? * Bitte stell die Blumen auf '''den''' Tisch. * Ich setzte mich lieber neben '''meinen''' Sohn. —[[User:Atcovi|Atcovi]] [[User talk:Atcovi|(Talk]] - [[Special:Contributions/Atcovi|Contribs)]] 22:21, 25 February 2022 (UTC) == Practice day #1 Notes (8/3/2022) == https://german.net/exercises/cases/accusative-dative/ * ihre vs ihren - "Der" Freunden, so "ihren". ;sentences * Der Maler malte mir '''ein''' tolles Bild. * Meine Schwester kauft unserem Bruder ein neue'''s''' Telefon. From what I've observed, the dative pronoun/object comes first while the accusative follows - the opposite flow as to when they are both pronouns (accusacative > dative). —[[User:Atcovi|Atcovi]] [[User talk:Atcovi|(Talk]] - [[Special:Contributions/Atcovi|Contribs)]] 23:47, 3 August 2022 (UTC) == Practice day #2 Notes (8/5/2022) == Same link as above. * Remember genders. * "Unser kleines Haus macht mir vieles (solution: viel) Arbeit." - why "vieles"? *use dative when in a place, accusative when movement is involved. *plural: "den" or "-en" infliction. —[[User:Atcovi|Atcovi]] [[User talk:Atcovi|(Talk]] - [[Special:Contributions/Atcovi|Contribs)]] 02:36, 6 August 2022 (UTC) 7b2ou7grwqqbm3bhgquvl0kfxmq277c 3 283895 2414008 2394462 2022-08-12T22:01:17Z Margob28 2943256 /* Nigerian English Varieties */ new section wikitext text/x-wiki {{Robelbox|theme=9|title=Welcome!|width=100%}} <div style="{{Robelbox/pad}}"> '''Hello and [[Wikiversity:Welcome|Welcome]] to [[Wikiversity:What is Wikiversity|Wikiversity]] Margob28!''' You can [[Wikiversity:Contact|contact us]] with [[Wikiversity:Questions|questions]] at the [[Wikiversity:Colloquium|colloquium]] or [[User talk:Dave Braunschweig|me personally]] when you need [[Help:Contents|help]]. Please remember to [[Wikiversity:Signature|sign and date]] your finished comments when [[Wikiversity:Who are Wikiversity participants?|participating]] in [[Wikiversity:Talk page|discussions]]. The signature icon [[File:OOjs UI icon signature-ltr.svg]] above the edit window makes it simple. All users are expected to abide by our [[Wikiversity:Privacy policy|Privacy]], [[Wikiversity:Civility|Civility]], and the [[Foundation:Terms of Use|Terms of Use]] policies while at Wikiversity. To [[Wikiversity:Introduction|get started]], you may <!-- The Left column --> <div style="width:50.0%; float:left"> * [[Help:guides|Take a guided tour]] and learn [[Help:Editing|to edit]]. * Visit a (kind of) [[Wikiversity:Random|random project]]. * [[Wikiversity:Browse|Browse]] Wikiversity, or visit a portal corresponding to your educational level: [[Portal: Pre-school Education|pre-school]], [[Portal: Primary Education|primary]], [[Portal:Secondary Education|secondary]], [[Portal:Tertiary Education|tertiary]], [[Portal:Non-formal Education|non-formal education]]. * Find out about [[Wikiversity:Research|research]] activities on Wikiversity. * [[Wikiversity:Introduction explore|Explore]] Wikiversity with the links to your left. </div> <!-- The Right column --> <div style="width:50.0%; float:left"> * Enable VisualEditor under [[Special:Preferences#mw-prefsection-betafeatures|Beta]] settings to make article editing easier. * Read an [[Wikiversity:Wikiversity teachers|introduction for teachers]] and find out [[Help:How to write an educational resource|how to write an educational resource]] for Wikiversity. * Give [[Wikiversity:Feedback|feedback]] about your initial observations. * Discuss Wikiversity issues or ask questions at the [[Wikiversity:Colloquium|colloquium]]. * [[Wikiversity:Chat|Chat]] with other Wikiversitans on [[:freenode:wikiversity|<kbd>#wikiversity</kbd>]]. </div> <br clear="both"/> You do not need to be an educator to edit. You only need to [[Wikiversity:Be bold|be bold]] to contribute and to experiment with the [[wikiversity:sandbox|sandbox]] or [[special:mypage|your userpage]]. See you around Wikiversity! --[[User:Dave Braunschweig|Dave Braunschweig]] ([[User talk:Dave Braunschweig|discuss]] • [[Special:Contributions/Dave Braunschweig|contribs]]) 12:44, 19 May 2022 (UTC)</div> <!-- Template:Welcome --> {{Robelbox/close}} == Nigerian English Varieties == As a non-native context, Nigeria has several taxonomy of English Varieties spoken within the Nigerian speech community. [[User:Margob28|Margob28]] ([[User talk:Margob28|discuss]] • [[Special:Contributions/Margob28|contribs]]) 22:01, 12 August 2022 (UTC) tpwdlkybj9ttrjofehip56b3ruamqy0 0 285217 2413978 2413916 2022-08-12T15:05:30Z Ncharamut 2824970 /* Goals */ added some edits up to onboarding steps wikitext text/x-wiki = Onboarding with HGAPS = Welcome new member! So, you're interested in joining your university's chapter of HGAPS? This onboarding guide should help. Onboarding is the process of integrating a member into a group, in this case, the process of getting a new member integrated into HGAPS (particularly HGAPS at the University of North Carolina at Chapel Hill). This document explains how to become onboarded into HGAPS including what training needs to be completed and how to become a member of a project team. This is especially important for new members or current members preparing for new members on their team. '''''Please ensure all onboarding steps are complete!''''' = What is HGAPS? = Although many new members may already know of HGAPS and its goals, if you are a new member and do not, this section describes more about how the organization functions. === Background === Helping Give Away Psychological Science (HGAPS) began as a student-led organization at the University of North Carolina at Chapel Hill (UNC-CH) in 2016. Since then, the organization has grown into an officially recognized nonprofit and has incorporated chapters from across the U.S. including the University of Maryland, Appalachian State University, and the University of California, Los Angeles. ==== Goals ==== Our mission is to bridge the science-practice gap by collecting, distilling, and sharing psychological science to promote well-being in the community. To do this, HGAPS strives to disseminate evidence-based psychological information to those who need it most, creating better access to reliable science. This is done by creating small, project-focused groups within the organization that work together to consolidate and share evidence-based information and resources while collaborating with researchers and clinicians around the globe. We mostly do this through free platforms such as Wikiversity (Wikipedia’s sister site for research and learning materials), YouTube, Open Science Framework (OSF) and Zotero. By granting access to free and reliable resources for assessment, diagnosis, treatment, and prevention purposes, we can help clinics and researchers that lack funding and resources to access evidence-based practices. Overall, the hope is to create tools and trainings to help future generations of practitioners and researchers while educating the general public. === Membership in a University Chapter of HGAPS === ==== Requirements ==== In the university chapter, members are decided by the university's individual bylaws for student organizations and will abide by each university's individual policies for student organizations. For UNC-CH, students must be '''full-time''' '''undergraduate''' '''or graduate''' '''students'''. Members must attend 30% of meetings performed in a given semester after they have joined the club. This means that if you joined mid-semester, you only need to attend 30% of the meetings after you join. If you will be leaving early, arriving late, or are unable to attend a meeting, let your project team know as soon as you discover your attendance will be impacted. Attendance is taken by the HGAPS Secretary on the RSVP sheet. Dues must also be paid according to the amount set in a given semester/year–typically $12 per semester or $20 per year. These dues will be collected through the HGAPS PayPal account. Finally, '''all members must have wiki accounts and perform the necessary trainings before making any edits.''' Members intending on pursuing future leadership positions should try to attend most meetings and refer to this [[Helping Give Away Psychological Science/Standard Operating Procedures/Growth in HGAPS|page]]. ==== Communication Etiquette ==== Within the organization, communication largely occurs over Slack or email in-between meetings; however, we prefer HGAPS related communication occur over Slack when possible. Please respond to all forms of communication within '''24 hours''' (or by Monday morning if a message is sent over the weekend). If you are not able to fully respond to the content of the email, please reply to acknowledge that you have seen the email and give a timeframe for when you expect to be able to respond more thoroughly. If an email is sent to you directly, you are expected to reply unless otherwise noted (e.g., "Just FYI"); if you are in the CC line, a reply is not expected or required. If you will be away or unable to respond to email for an extended time period, an out of office message is useful to let others know not to expect a reply within the 24-hour timeframe. Replying to project leaders, faculty, grad student advisors, or other HGAPS team members is a great time to practice your email etiquette. If you are unsure how to professionally respond to an email, please let an advisor know as we would be happy to help you learn! Some basic rules include ALWAYS including a subject, a greeting, and a closing in your email, and making sure to use proper grammar and punctuation. Other suggestions include bolding, highlighting, or re-listing items requiring follow-up or action from the person you are emailing at the end of the email; taking the initiative on scheduling with others; and being clear about meeting/call times (e.g., "Our call is scheduled for this '''Thursday, 5/21, at 6:00pm EST.''' I look forward to our discussion!"). If you only require a response from one person, please message them directly rather than sending a message to the entire group. Before sending an email to the group, ask yourself if the topic is relevant to everyone, if email is the best medium for communicating that specific item (versus a Slack message or an in-person chat), and if the item can wait till the next meeting to discuss. We all receive a lot of emails and want to ensure we are not abusing the power to contact our team members instantly with a non-urgent question or comment. ==== Project Teams ==== HGAPS splits members into different project teams focusing on different tasks that aid in the dissemination of psychological research and resources. In the case of UNC–CH, projects are also enumerated, so 1022 equates to the team working on updating the Standard Operating Procedures (SOPs). Sometimes, these team goals may overlap, get passed between different teams, or end up involving more than one team at the same time. For instance, at UNC-CH the Translations team translates assessment measures into different languages for the Assessment Center team, and then the Social Media group could post their accomplishments on Twitter! Members may participate in more than one group, but during the school year, focusing on one is advisable (see Meetings below). Each group has a leader position designated as a "Water Carrier (WC)". This is a business term and our version of a team leader–the difference is, a water carrier doesn't indicate prior experience or seniority. Water carriers mainly lead by organizing the group and planning meetings, but they need no experience–in fact, a water carrier's job may entail asking others to help with their expertise. The term water carrier is used for this reason–to decrease feelings of superiority/inferiority while maintaining a structure to the groups. For more information, please refer to this SOP. ==== Meetings ==== ===== During the Academic Year ===== UNC-CH HGAPS holds general "working" meetings on Thursday evenings from 6–8pm ET in a hybrid format utilizing the President's zoom and a designated meeting room on campus during the academic year. In the instance that the health of HGAPS members is put at risk by having in-person meetings, all meetings will occur via Zoom with no in person option available. The zoom links are sent in advance and you can sign up for weekly reminders through our Luma calendar. These meetings are working meetings, so during these two hours, members split into breakout rooms (in groups in person) to work with their teams. Attendance is taken via the RSVP sheet, an excel sheet sent out by the President each meeting. Each member is responsible for noting their attendance and whether they left early- for this reason, we recommend bookmarking the RSVP sheet. These meetings are typically outlined as follows: * Introduction: 6:00–6:15pm ** Members share how they are doing and any personal updates. Then, the Professor (Dr. Youngstrom in our case) or the President may give overall updates, such as different grant updates. This gives a chance for the President to organize breakout rooms. * Breakout rooms: 6:15–7:45pm ** Members work in their groups. At the end, the water carrier (see Project Teams above) notes the teams accomplishments on a Google Doc used by the President and Faculty Advisor to keep track of the team's accomplishments. * Report out: 7:45–8:00pm ** This is when each water carrier reports to the group what was accomplished and the Faculty Advisor gives final updates and/or announcements before concluding the meeting. Aside from the general working meetings, specific teams may choose to meet outside of the general meeting time, so there may be instances where teams meet at a different time. You may also see that these working meetings continue through school breaks–don't worry, those are optional for UNC students. ===== During the Summer ===== The HGAPS executive committee and other members who are highly involved throughout the course of the academic year may be given the opportunity to work as a paid, independent contractor over the summer, depending on the availability of funds and resources. If you are offered and accept this opportunity, you will be required to sign an Independent Contractor Agreement and fill out a W-9. Your scope of work will be determined before the summer and included in the Agreement. Summer workers can work on predetermined, funded projects for pay (other projects may be completed as volunteer work), though this is subject to change depending on the availability of funds. Payment will be administered on a monthly basis and should be received during the first week of the month for all paid work completed during the previous month (e.g., you will be paid for the work you completed from June 1st to June 30th during the first week of July). Contractors are responsible for tracking their hours worked on funded projects on the appropriate tab on the tracking sheet, include detailed descriptions of what project you worked on, what work was completed, and how many hours you worked (every 15 minutes counts, so you can track in 0.25 increments). Please be honest about how many hours you worked on a given projects and which projects you worked on (i.e., do not say that you worked on a funded project when you worked on an unfunded project); the research coordinator will check hours at the end of every month before sending payment. '''SUMMER 2022 (to be updated each year):''' HGAPS general meetings/editing sessions are held Thursday evenings from 6:00-8:00pm EST via Zoom. A member of the executive team will often send the RSVP sheet during the meetings via Zoom Chat so that attendance can be recorded. Within these meetings, the President will create breakout rooms based on specific projects that members can enter once prompted by the President. It is expected that each team creates an agenda and takes notes each meeting based on a predetermined [https://docs.google.com/document/d/1OXnGfmjrAqf5pVV_SSxRiK4399mdFvPoBoRaTeYrsJc/edit template]. The currently funded projects for Summer 2022 are Conferences, APS, SOPs, OToPS, Translations, Assessment Portfolios, Squid Game, Updating EBAs, Social Media, Speaker Series, Operations Manual, and Redcap; all other projects are done on a volunteer basis or may be funded in the future depending on acquisition of additional funds. ===== Editing Meetings (Edit-a-thons) ===== Edit-a-thons are specific HGAPS meetings in which clinicians, researchers, and other stakeholders are recruited to help edit HGAPS content and direct the club toward objectives that are pertinent to current issues in the field. We have had local clinicians, researchers, and organizations (e.g., [https://www.nami.org/Home NAMI]) attend in-person meetings and held teleconferences with other leaders in the field in the past. Edit-a-thons occur throughout the year and are organized by the executive team or an outreach coordinator designated specifically for edit-a-thon planning. They are typically held in larger spaces (e.g., the library) to accommodate extra guests and sometimes provide “special” food outside of the usual pizza. Visitors work alongside HGAPS members to view and edit content and make suggestions for other topics, projects, and edits. Edit-a-thons are a great opportunity to network with leaders in the field and show off your Wiki skills! To learn more, please refer to the [https://docs.google.com/document/d/1GzKFhpO694e4ai8FNtMLC2JGt7ffqqWdJ_-rL84gQ60/edit#heading=h.klvg718pd1zd Edit-a-thon SOP]. ==== Additional Opportunities for Members ==== ===== Wiki Authorship ===== HGAPS has recently begun turning Wiki pages into WikiJournal articles for publication. This is a great opportunity to add to your CV/resume and contribute to science in a meaningful way. We have learned that the best way to avoid hurt feelings is to be fully transparent about authorship. Dr. Youngstrom devised a system that fairly (or as fairly as possible, as these situations can be complicated) awards points toward authorship for different publication-related tasks. Please be sure to fill out an [https://docs.google.com/spreadsheets/d/12gh8mQHBxBzJUQSvu6wPmq1zSCOnhWcxceI61Z9G7Vw/edit#gid=1170307374 AARF] with your team if you are involved in a project that hopes to result in publication BEFORE you begin writing, or as early as possible in the process. You can reach out to Dr. Youngstrom or the graduate advisors if you are unsure about how to use the AARF. More details about submitting an article to a WikiJournal via HGAPS can be found in our [[Helping Give Away Psychological Science/Standard Operating Procedures/ Wiki Journal|WikiJournal Guide]]. ===== Conferences ===== HGAPS members have the opportunity to submit abstracts to and attend various conferences throughout the year. HGAPS tries to create opportunities to attend conferences by taking notes and helping students submit [[Helping Give Away Psychological Science/Standard Operating Procedures/Making a Poster|poster abstracts]]. Take a look at our tips for [[Helping Give Away Psychological Science/Standard Operating Procedures/Tips for Conference Attendance|attending conferences]] if you are considering submitting your own work or taking notes for HGAPS at an upcoming conference. Conferences occur throughout the year, and locations and dates vary by conference. Most conferences occur around the same time every year, though actual dates vary. Conference locations tend to shift each year. National conferences can take place anywhere in the United States, and international conferences may be anywhere across the globe. Conferences should have their own individual websites. Some of the conferences we frequent are [https://jccapfuturedirectionsforum.weebly.com/ Future Directions Forum], [https://ccf.fiu.edu/miami-international-child-adolescent-mental-health-conference/ Miami International Child & Adolescent Mental Health], [https://convention.apa.org/ American Psychological Association], and [https://www.abct.org/ Association Behavioral Cognitive Therapy]. == Onboarding Steps == Now that you know what you're joining, here are the steps you should follow in order to involve yourself in HGAPS as quickly and easily as possible. '''Step 1: Create a Wikipedia account and join the main means of communication.''' Before your first meeting, it’s helpful to at least have a Wikipedia account created. That way, if you’re interested in becoming a member, you can follow along with the page changes being made by the rest of your team members during the meetings. Read '''<u>Getting Step Up</u>''' on [[Helping_Give_Away_Psychological_Science/Standard_Operating_Procedures/_Getting_Started|this page]] to learn how create a Wikipedia account. Luckily, this will create a Wikiversity account too! '''Slack''' As for communication, for UNC-CH, we primarily use [https://slack.com/ Slack]. Slack is a business platform where people can easily message, @ each other and communicate with people through multiple channels and even an app. We recommend you download the app as to not miss important notifications. Although email reminders will still be sent, most meeting reminders and general information will be sent on Slack. In our Slack, the #general and #newmembers-[term] channels will be used for any meeting updates and important news. Project channels on the other hand will be used for project teams to communicate with each other, share resources with one another, and plan separate team meetings if necessary. To join, simply ask an executive member to add you to the general channel (it'll send you a time-limited invite) or ask your water carrier (WC) to add you into the necessary project channel. With all that in mind, go ahead and join to get connected with our team! '''Step 2: Attend your first meeting.''' As a new member, simply ask the President to stay behind or create a breakout room for new members–they’ll introduce you to the current projects, and you’ll have the opportunity to sit in and see if that project interests you! At that point, the water carrier will introduce you to the specifics and see what they can do about getting you up to speed as soon as possible. However, it's important to note that editing cannot be performed before completing the necessary trainings, so this introduction is just to help you understand the project's layout. * Tip: if you and your water carrier are unsure of where to start, ask them to share their screen and walk you through their slack channel and project! At this point, if you would like to stay and are from UNC, please visit the [https://heellife.unc.edu/organization/hgaps heellife] page and request HGAPS membership. Once that is finished, if you are currently unable to help and are given permission by your group's water carrier to do so during the meeting, you may move on to steps 3-4. '''Step 3: Create your accounts.''' HGAPS uses a variety of free platforms for different purposes as seen on the RSVP sheet. Two prominent examples are OSF and Zotero. used for uploading documents and creating citations, respectfully. Although not all projects require these accounts, it's good to have them in case a future project needs them. So make sure you: * Follow [https://osf.io/register?campaign=&next=&view_only= this link] to create an OSF and add it to your RSVP sheet. It's recommended to use a personal email to ensure access to the account after graduation. For more information on OSF, should you need it, follow this [[Helping Give Away Psychological Science/Standard Operating Procedures/ OSF Basics|link]]. * Follow [https://www.zotero.org/user/register this link] to create a Zotero and add it to your RSVP sheet. It's recommended to use a personal email to ensure access to the account after graduation. For more information on Zotero, should you need it, follow this [https://drive.google.com/file/d/1pfWLXd9cNVOLlCG0yydM_O8XWjUI4Osv/view?usp=sharing link]. * Ask your project if any other platforms are being used! For instance, Social Media frequently uses [https://www.canva.com/ Canva], an online graphic design platform. There, the leader must add the new user to a workgroup to work on the same project. So just ask and make sure you have everything you need! '''Step 4: Complete your trainings and report back.''' There are two trainings that must be complete in order to edit. These ensure your edits don't get removed by wiki. First training: Begin by completing the Wiki Training Modules here: https://dashboard.wikiedu.org/   * Sign in with your Wiki account. * Go to the "Training" tab. * Complete the "Student Training" Modules. * Make sure to finish the "Basics" and "Special Topics" sections! This should take about an hour or less. Ensure you're signed in so that your progress remains saved on your account. Second training: Complete the Wikipedia Adventure linked below. * Wikipedia:The Wikipedia Adventure * Ensure you have all 15 badges at the end! [[File:Userpageparroda.png|thumb|A standard Wiki User page where the user writes their major, mentor, and involvement in HGAPS.]] This training will take a bit longer, approximately an hour or a bit more. It includes music and details the layout of Wikipedia from within Wikipedia, guiding you on your first edits. At that point, go ahead and add some more information onto your user page- for example, go ahead and add HGAPS to your wiki profile (right). After this, you're all set with your trainings! Report back to your water carrier and to any HGAPS Exec member. An HGAPS Exec will then add you to HGAPS-relevant Wiki groups (including the HGAPS User Group and the HGAPS WikiEdu dashboard) while your water carrier will help you get more involved on their specific project. = Further information = === What if I have more questions? === Please reach out, we are here to help! HGAPS has a lot of exciting projects and components, and we know that getting started can seem overwhelming. Phoebe Rodda (UNC Chapter President) and Julia Bondareva (UNC Chapter Treasurer) are available through Slack for any questions. Dr. Youngstrom is as well, but as he is very busy we encourage you to direct questions that are not Eric-specific elsewhere first, if possible. === Who are the main HGAPS Exec that I will interact with? === * Eric Youngstrom, PhD (he/him) - HGAPS CEO, Founder and Faculty Advisor * Natalie Charamut (she/her) - HGAPS Assistant Executive Director '''(currently working on PhD, may not be very available but is very knowledgeable!)''' * Phoebe Rodda (she/her) - HGAPS UNC Chapter President * Julia Bondareva (they/them) - HGAPS UNC Chapter Treasurer * Maddie Gray (she/her) - HGAPS UNC Chapter Secretary * Thamasi Sagi (she/her) - HGAPS UNC Chapter Social Media Chair * Maggie Wong (she/her) - HGAPS UNC Chapter Past-President === Where can I find out more? === If you'd like more information about the history of HGAPS and different events you can be involved in through HGAPS, feel free to check out the HGAPS site linked [https://www.hgaps.org/ here], or this page of other [[Helping Give Away Psychological Science/Standard Operating Procedures|Standard Operating Procedures (SOPs)]]. Happy editing, we're glad to have you! b8evbk8waoiens1cr51snp12rsi0vfk 2413979 2413978 2022-08-12T15:15:18Z Ncharamut 2824970 /* Onboarding Steps */ made edits up to further information wikitext text/x-wiki = Onboarding with HGAPS = Welcome new member! So, you're interested in joining your university's chapter of HGAPS? This onboarding guide should help. Onboarding is the process of integrating a member into a group, in this case, the process of getting a new member integrated into HGAPS (particularly HGAPS at the University of North Carolina at Chapel Hill). This document explains how to become onboarded into HGAPS including what training needs to be completed and how to become a member of a project team. This is especially important for new members or current members preparing for new members on their team. '''''Please ensure all onboarding steps are complete!''''' = What is HGAPS? = Although many new members may already know of HGAPS and its goals, if you are a new member and do not, this section describes more about how the organization functions. === Background === Helping Give Away Psychological Science (HGAPS) began as a student-led organization at the University of North Carolina at Chapel Hill (UNC-CH) in 2016. Since then, the organization has grown into an officially recognized nonprofit and has incorporated chapters from across the U.S. including the University of Maryland, Appalachian State University, and the University of California, Los Angeles. ==== Goals ==== Our mission is to bridge the science-practice gap by collecting, distilling, and sharing psychological science to promote well-being in the community. To do this, HGAPS strives to disseminate evidence-based psychological information to those who need it most, creating better access to reliable science. This is done by creating small, project-focused groups within the organization that work together to consolidate and share evidence-based information and resources while collaborating with researchers and clinicians around the globe. We mostly do this through free platforms such as Wikiversity (Wikipedia’s sister site for research and learning materials), YouTube, Open Science Framework (OSF) and Zotero. By granting access to free and reliable resources for assessment, diagnosis, treatment, and prevention purposes, we can help clinics and researchers that lack funding and resources to access evidence-based practices. Overall, the hope is to create tools and trainings to help future generations of practitioners and researchers while educating the general public. === Membership in a University Chapter of HGAPS === ==== Requirements ==== In the university chapter, members are decided by the university's individual bylaws for student organizations and will abide by each university's individual policies for student organizations. For UNC-CH, students must be '''full-time''' '''undergraduate''' '''or graduate''' '''students'''. Members must attend 30% of meetings performed in a given semester after they have joined the club. This means that if you joined mid-semester, you only need to attend 30% of the meetings after you join. If you will be leaving early, arriving late, or are unable to attend a meeting, let your project team know as soon as you discover your attendance will be impacted. Attendance is taken by the HGAPS Secretary on the RSVP sheet. Dues must also be paid according to the amount set in a given semester/year–typically $12 per semester or $20 per year. These dues will be collected through the HGAPS PayPal account. Finally, '''all members must have wiki accounts and perform the necessary trainings before making any edits.''' Members intending on pursuing future leadership positions should try to attend most meetings and refer to this [[Helping Give Away Psychological Science/Standard Operating Procedures/Growth in HGAPS|page]]. ==== Communication Etiquette ==== Within the organization, communication largely occurs over Slack or email in-between meetings; however, we prefer HGAPS related communication occur over Slack when possible. Please respond to all forms of communication within '''24 hours''' (or by Monday morning if a message is sent over the weekend). If you are not able to fully respond to the content of the email, please reply to acknowledge that you have seen the email and give a timeframe for when you expect to be able to respond more thoroughly. If an email is sent to you directly, you are expected to reply unless otherwise noted (e.g., "Just FYI"); if you are in the CC line, a reply is not expected or required. If you will be away or unable to respond to email for an extended time period, an out of office message is useful to let others know not to expect a reply within the 24-hour timeframe. Replying to project leaders, faculty, grad student advisors, or other HGAPS team members is a great time to practice your email etiquette. If you are unsure how to professionally respond to an email, please let an advisor know as we would be happy to help you learn! Some basic rules include ALWAYS including a subject, a greeting, and a closing in your email, and making sure to use proper grammar and punctuation. Other suggestions include bolding, highlighting, or re-listing items requiring follow-up or action from the person you are emailing at the end of the email; taking the initiative on scheduling with others; and being clear about meeting/call times (e.g., "Our call is scheduled for this '''Thursday, 5/21, at 6:00pm EST.''' I look forward to our discussion!"). If you only require a response from one person, please message them directly rather than sending a message to the entire group. Before sending an email to the group, ask yourself if the topic is relevant to everyone, if email is the best medium for communicating that specific item (versus a Slack message or an in-person chat), and if the item can wait till the next meeting to discuss. We all receive a lot of emails and want to ensure we are not abusing the power to contact our team members instantly with a non-urgent question or comment. ==== Project Teams ==== HGAPS splits members into different project teams focusing on different tasks that aid in the dissemination of psychological research and resources. In the case of UNC–CH, projects are also enumerated, so 1022 equates to the team working on updating the Standard Operating Procedures (SOPs). Sometimes, these team goals may overlap, get passed between different teams, or end up involving more than one team at the same time. For instance, at UNC-CH the Translations team translates assessment measures into different languages for the Assessment Center team, and then the Social Media group could post their accomplishments on Twitter! Members may participate in more than one group, but during the school year, focusing on one is advisable (see Meetings below). Each group has a leader position designated as a "Water Carrier (WC)". This is a business term and our version of a team leader–the difference is, a water carrier doesn't indicate prior experience or seniority. Water carriers mainly lead by organizing the group and planning meetings, but they need no experience–in fact, a water carrier's job may entail asking others to help with their expertise. The term water carrier is used for this reason–to decrease feelings of superiority/inferiority while maintaining a structure to the groups. For more information, please refer to this SOP. ==== Meetings ==== ===== During the Academic Year ===== UNC-CH HGAPS holds general "working" meetings on Thursday evenings from 6–8pm ET in a hybrid format utilizing the President's zoom and a designated meeting room on campus during the academic year. In the instance that the health of HGAPS members is put at risk by having in-person meetings, all meetings will occur via Zoom with no in person option available. The zoom links are sent in advance and you can sign up for weekly reminders through our Luma calendar. These meetings are working meetings, so during these two hours, members split into breakout rooms (in groups in person) to work with their teams. Attendance is taken via the RSVP sheet, an excel sheet sent out by the President each meeting. Each member is responsible for noting their attendance and whether they left early- for this reason, we recommend bookmarking the RSVP sheet. These meetings are typically outlined as follows: * Introduction: 6:00–6:15pm ** Members share how they are doing and any personal updates. Then, the Professor (Dr. Youngstrom in our case) or the President may give overall updates, such as different grant updates. This gives a chance for the President to organize breakout rooms. * Breakout rooms: 6:15–7:45pm ** Members work in their groups. At the end, the water carrier (see Project Teams above) notes the teams accomplishments on a Google Doc used by the President and Faculty Advisor to keep track of the team's accomplishments. * Report out: 7:45–8:00pm ** This is when each water carrier reports to the group what was accomplished and the Faculty Advisor gives final updates and/or announcements before concluding the meeting. Aside from the general working meetings, specific teams may choose to meet outside of the general meeting time, so there may be instances where teams meet at a different time. You may also see that these working meetings continue through school breaks–don't worry, those are optional for UNC students. ===== During the Summer ===== The HGAPS executive committee and other members who are highly involved throughout the course of the academic year may be given the opportunity to work as a paid, independent contractor over the summer, depending on the availability of funds and resources. If you are offered and accept this opportunity, you will be required to sign an Independent Contractor Agreement and fill out a W-9. Your scope of work will be determined before the summer and included in the Agreement. Summer workers can work on predetermined, funded projects for pay (other projects may be completed as volunteer work), though this is subject to change depending on the availability of funds. Payment will be administered on a monthly basis and should be received during the first week of the month for all paid work completed during the previous month (e.g., you will be paid for the work you completed from June 1st to June 30th during the first week of July). Contractors are responsible for tracking their hours worked on funded projects on the appropriate tab on the tracking sheet, include detailed descriptions of what project you worked on, what work was completed, and how many hours you worked (every 15 minutes counts, so you can track in 0.25 increments). Please be honest about how many hours you worked on a given projects and which projects you worked on (i.e., do not say that you worked on a funded project when you worked on an unfunded project); the research coordinator will check hours at the end of every month before sending payment. '''SUMMER 2022 (to be updated each year):''' HGAPS general meetings/editing sessions are held Thursday evenings from 6:00-8:00pm EST via Zoom. A member of the executive team will often send the RSVP sheet during the meetings via Zoom Chat so that attendance can be recorded. Within these meetings, the President will create breakout rooms based on specific projects that members can enter once prompted by the President. It is expected that each team creates an agenda and takes notes each meeting based on a predetermined [https://docs.google.com/document/d/1OXnGfmjrAqf5pVV_SSxRiK4399mdFvPoBoRaTeYrsJc/edit template]. The currently funded projects for Summer 2022 are Conferences, APS, SOPs, OToPS, Translations, Assessment Portfolios, Squid Game, Updating EBAs, Social Media, Speaker Series, Operations Manual, and Redcap; all other projects are done on a volunteer basis or may be funded in the future depending on acquisition of additional funds. ===== Editing Meetings (Edit-a-thons) ===== Edit-a-thons are specific HGAPS meetings in which clinicians, researchers, and other stakeholders are recruited to help edit HGAPS content and direct the club toward objectives that are pertinent to current issues in the field. We have had local clinicians, researchers, and organizations (e.g., [https://www.nami.org/Home NAMI]) attend in-person meetings and held teleconferences with other leaders in the field in the past. Edit-a-thons occur throughout the year and are organized by the executive team or an outreach coordinator designated specifically for edit-a-thon planning. They are typically held in larger spaces (e.g., the library) to accommodate extra guests and sometimes provide “special” food outside of the usual pizza. Visitors work alongside HGAPS members to view and edit content and make suggestions for other topics, projects, and edits. Edit-a-thons are a great opportunity to network with leaders in the field and show off your Wiki skills! To learn more, please refer to the [https://docs.google.com/document/d/1GzKFhpO694e4ai8FNtMLC2JGt7ffqqWdJ_-rL84gQ60/edit#heading=h.klvg718pd1zd Edit-a-thon SOP]. ==== Additional Opportunities for Members ==== ===== Wiki Authorship ===== HGAPS has recently begun turning Wiki pages into WikiJournal articles for publication. This is a great opportunity to add to your CV/resume and contribute to science in a meaningful way. We have learned that the best way to avoid hurt feelings is to be fully transparent about authorship. Dr. Youngstrom devised a system that fairly (or as fairly as possible, as these situations can be complicated) awards points toward authorship for different publication-related tasks. Please be sure to fill out an [https://docs.google.com/spreadsheets/d/12gh8mQHBxBzJUQSvu6wPmq1zSCOnhWcxceI61Z9G7Vw/edit#gid=1170307374 AARF] with your team if you are involved in a project that hopes to result in publication BEFORE you begin writing, or as early as possible in the process. You can reach out to Dr. Youngstrom or the graduate advisors if you are unsure about how to use the AARF. More details about submitting an article to a WikiJournal via HGAPS can be found in our [[Helping Give Away Psychological Science/Standard Operating Procedures/ Wiki Journal|WikiJournal Guide]]. ===== Conferences ===== HGAPS members have the opportunity to submit abstracts to and attend various conferences throughout the year. HGAPS tries to create opportunities to attend conferences by taking notes and helping students submit [[Helping Give Away Psychological Science/Standard Operating Procedures/Making a Poster|poster abstracts]]. Take a look at our tips for [[Helping Give Away Psychological Science/Standard Operating Procedures/Tips for Conference Attendance|attending conferences]] if you are considering submitting your own work or taking notes for HGAPS at an upcoming conference. Conferences occur throughout the year, and locations and dates vary by conference. Most conferences occur around the same time every year, though actual dates vary. Conference locations tend to shift each year. National conferences can take place anywhere in the United States, and international conferences may be anywhere across the globe. Conferences should have their own individual websites. Some of the conferences we frequent are [https://jccapfuturedirectionsforum.weebly.com/ Future Directions Forum], [https://ccf.fiu.edu/miami-international-child-adolescent-mental-health-conference/ Miami International Child & Adolescent Mental Health], [https://convention.apa.org/ American Psychological Association], and [https://www.abct.org/ Association Behavioral Cognitive Therapy]. == Onboarding Steps == Now that you know what you're joining, here are the steps you should follow in order to involve yourself in HGAPS as quickly and easily as possible. '''Step 1: Create a Wikipedia account and join the main means of communication.''' Before your first meeting, it’s helpful to at least have a Wikipedia account created. That way, if you’re interested in becoming a member, you can follow along with the page changes being made by the rest of your team members during the meetings. Read '''<u>Getting Step Up</u>''' on [[Helping_Give_Away_Psychological_Science/Standard_Operating_Procedures/_Getting_Started|this page]] to learn how create a Wikipedia account. Luckily, this will create a Wikiversity account too! '''Slack''' As for communication, for UNC-CH, we primarily use [https://slack.com/ Slack]. Slack is a business platform where people can easily message, @ each other and communicate with people through multiple channels and even an app. We recommend you download the app as to not miss important notifications. Although email reminders will still be sent for the Thursday working meeting, most meeting reminders, general information, and team specific announcements will be sent over Slack. In our Slack, the #general and #newmembers-[term] channels will be used for any meeting updates and important news. Project channels on the other hand will be used for project teams to communicate with each other, share resources with one another, and plan separate team meetings if necessary. To join, simply ask an executive member to add you to the general channel (it'll send you a time-limited invite) or ask your water carrier (WC) to add you into the necessary project channel. With all that in mind, go ahead and join to get connected with our team! '''Step 2: Attend your first meeting.''' As a new member, simply ask the President to stay behind or create a breakout room for new members–they’ll introduce you to the current projects, and you’ll have the opportunity to sit in and see if that project interests you! At that point, the water carrier will introduce you to the specifics and see what they can do about getting you up to speed as soon as possible. However, it's important to note that editing cannot be performed before completing the necessary trainings, so this introduction is just to help you understand the project's layout. * Tip: if you and your water carrier are unsure of where to start, ask them to share their screen and walk you through their slack channel and the project objectives and key results! At this point, if you would like to stay and are from UNC, please visit the [https://heellife.unc.edu/organization/hgaps heellife] page and request HGAPS membership. Once that is finished, if you are currently unable to help and are given permission by your group's water carrier to do so during the meeting, you may move on to steps 3-4. '''Step 3: Create your accounts.''' HGAPS uses a variety of free platforms for different purposes as seen on the RSVP sheet. Two prominent examples are OSF and Zotero. used for uploading documents and creating citations, respectfully. Although not all projects require these accounts, it's good to have them in case a future project needs them. So make sure you: * Follow [https://osf.io/register?campaign=&next=&view_only= this link] to create an OSF and add it to your RSVP sheet. It's recommended to use a personal email to ensure access to the account after graduation. For more information on OSF, should you need it, follow this [[Helping Give Away Psychological Science/Standard Operating Procedures/ OSF Basics|link]]. * Follow [https://www.zotero.org/user/register this link] to create a Zotero and add it to your RSVP sheet. It's recommended to use a personal email to ensure access to the account after graduation. For more information on Zotero, should you need it, follow this [https://drive.google.com/file/d/1pfWLXd9cNVOLlCG0yydM_O8XWjUI4Osv/view?usp=sharing link]. * Ask your project if any other platforms are being used! For instance, Social Media frequently uses [https://www.canva.com/ Canva], an online graphic design platform. There, the leader must add the new user to a workgroup to work on the same project. So just ask and make sure you have everything you need! '''Step 4: Complete your trainings and report back.''' There are two trainings that must be complete in order to edit. These ensure your edits don't get removed by wiki. First training: Begin by completing the Wiki Training Modules here: https://dashboard.wikiedu.org/   * Sign in with your Wiki account. * Go to the "Training" tab. * Complete the "Student Training" Modules. * Make sure to finish the "Basics" and "Special Topics" sections! This should take about an hour or less. Ensure you're signed in so that your progress remains saved on your account. Second training: Complete the Wikipedia Adventure linked below. * Wikipedia:The Wikipedia Adventure * Ensure you have all 15 badges at the end! [[File:Userpageparroda.png|thumb|A standard Wiki User page where the user writes their major, mentor, and involvement in HGAPS.]] This training will take a bit longer, approximately an hour or a bit more. It includes music and details the layout of Wikipedia from within Wikipedia, guiding you on your first edits. At that point, go ahead and add some more information onto your user page- for example, go ahead and add HGAPS to your wiki profile (right). After this, you're all set with your trainings! Report back to your water carrier and to any HGAPS Exec member. An HGAPS Exec will then add you to HGAPS-relevant Wiki groups (including the HGAPS User Group and the HGAPS WikiEdu dashboard) while your water carrier will help you get more involved on their specific project. = Further information = === What if I have more questions? === Please reach out, we are here to help! HGAPS has a lot of exciting projects and components, and we know that getting started can seem overwhelming. Phoebe Rodda (UNC Chapter President) and Julia Bondareva (UNC Chapter Treasurer) are available through Slack for any questions. Dr. Youngstrom is as well, but as he is very busy we encourage you to direct questions that are not Eric-specific elsewhere first, if possible. === Who are the main HGAPS Exec that I will interact with? === * Eric Youngstrom, PhD (he/him) - HGAPS CEO, Founder and Faculty Advisor * Natalie Charamut (she/her) - HGAPS Assistant Executive Director '''(currently working on PhD, may not be very available but is very knowledgeable!)''' * Phoebe Rodda (she/her) - HGAPS UNC Chapter President * Julia Bondareva (they/them) - HGAPS UNC Chapter Treasurer * Maddie Gray (she/her) - HGAPS UNC Chapter Secretary * Thamasi Sagi (she/her) - HGAPS UNC Chapter Social Media Chair * Maggie Wong (she/her) - HGAPS UNC Chapter Past-President === Where can I find out more? === If you'd like more information about the history of HGAPS and different events you can be involved in through HGAPS, feel free to check out the HGAPS site linked [https://www.hgaps.org/ here], or this page of other [[Helping Give Away Psychological Science/Standard Operating Procedures|Standard Operating Procedures (SOPs)]]. Happy editing, we're glad to have you! jyrg3nue9qvpzwapwo3nh605f3ihpf9 2413980 2413979 2022-08-12T15:18:26Z Ncharamut 2824970 /* Onboarding Steps */ updated step 2 wikitext text/x-wiki = Onboarding with HGAPS = Welcome new member! So, you're interested in joining your university's chapter of HGAPS? This onboarding guide should help. Onboarding is the process of integrating a member into a group, in this case, the process of getting a new member integrated into HGAPS (particularly HGAPS at the University of North Carolina at Chapel Hill). This document explains how to become onboarded into HGAPS including what training needs to be completed and how to become a member of a project team. This is especially important for new members or current members preparing for new members on their team. '''''Please ensure all onboarding steps are complete!''''' = What is HGAPS? = Although many new members may already know of HGAPS and its goals, if you are a new member and do not, this section describes more about how the organization functions. === Background === Helping Give Away Psychological Science (HGAPS) began as a student-led organization at the University of North Carolina at Chapel Hill (UNC-CH) in 2016. Since then, the organization has grown into an officially recognized nonprofit and has incorporated chapters from across the U.S. including the University of Maryland, Appalachian State University, and the University of California, Los Angeles. ==== Goals ==== Our mission is to bridge the science-practice gap by collecting, distilling, and sharing psychological science to promote well-being in the community. To do this, HGAPS strives to disseminate evidence-based psychological information to those who need it most, creating better access to reliable science. This is done by creating small, project-focused groups within the organization that work together to consolidate and share evidence-based information and resources while collaborating with researchers and clinicians around the globe. We mostly do this through free platforms such as Wikiversity (Wikipedia’s sister site for research and learning materials), YouTube, Open Science Framework (OSF) and Zotero. By granting access to free and reliable resources for assessment, diagnosis, treatment, and prevention purposes, we can help clinics and researchers that lack funding and resources to access evidence-based practices. Overall, the hope is to create tools and trainings to help future generations of practitioners and researchers while educating the general public. === Membership in a University Chapter of HGAPS === ==== Requirements ==== In the university chapter, members are decided by the university's individual bylaws for student organizations and will abide by each university's individual policies for student organizations. For UNC-CH, students must be '''full-time''' '''undergraduate''' '''or graduate''' '''students'''. Members must attend 30% of meetings performed in a given semester after they have joined the club. This means that if you joined mid-semester, you only need to attend 30% of the meetings after you join. If you will be leaving early, arriving late, or are unable to attend a meeting, let your project team know as soon as you discover your attendance will be impacted. Attendance is taken by the HGAPS Secretary on the RSVP sheet. Dues must also be paid according to the amount set in a given semester/year–typically $12 per semester or $20 per year. These dues will be collected through the HGAPS PayPal account. Finally, '''all members must have wiki accounts and perform the necessary trainings before making any edits.''' Members intending on pursuing future leadership positions should try to attend most meetings and refer to this [[Helping Give Away Psychological Science/Standard Operating Procedures/Growth in HGAPS|page]]. ==== Communication Etiquette ==== Within the organization, communication largely occurs over Slack or email in-between meetings; however, we prefer HGAPS related communication occur over Slack when possible. Please respond to all forms of communication within '''24 hours''' (or by Monday morning if a message is sent over the weekend). If you are not able to fully respond to the content of the email, please reply to acknowledge that you have seen the email and give a timeframe for when you expect to be able to respond more thoroughly. If an email is sent to you directly, you are expected to reply unless otherwise noted (e.g., "Just FYI"); if you are in the CC line, a reply is not expected or required. If you will be away or unable to respond to email for an extended time period, an out of office message is useful to let others know not to expect a reply within the 24-hour timeframe. Replying to project leaders, faculty, grad student advisors, or other HGAPS team members is a great time to practice your email etiquette. If you are unsure how to professionally respond to an email, please let an advisor know as we would be happy to help you learn! Some basic rules include ALWAYS including a subject, a greeting, and a closing in your email, and making sure to use proper grammar and punctuation. Other suggestions include bolding, highlighting, or re-listing items requiring follow-up or action from the person you are emailing at the end of the email; taking the initiative on scheduling with others; and being clear about meeting/call times (e.g., "Our call is scheduled for this '''Thursday, 5/21, at 6:00pm EST.''' I look forward to our discussion!"). If you only require a response from one person, please message them directly rather than sending a message to the entire group. Before sending an email to the group, ask yourself if the topic is relevant to everyone, if email is the best medium for communicating that specific item (versus a Slack message or an in-person chat), and if the item can wait till the next meeting to discuss. We all receive a lot of emails and want to ensure we are not abusing the power to contact our team members instantly with a non-urgent question or comment. ==== Project Teams ==== HGAPS splits members into different project teams focusing on different tasks that aid in the dissemination of psychological research and resources. In the case of UNC–CH, projects are also enumerated, so 1022 equates to the team working on updating the Standard Operating Procedures (SOPs). Sometimes, these team goals may overlap, get passed between different teams, or end up involving more than one team at the same time. For instance, at UNC-CH the Translations team translates assessment measures into different languages for the Assessment Center team, and then the Social Media group could post their accomplishments on Twitter! Members may participate in more than one group, but during the school year, focusing on one is advisable (see Meetings below). Each group has a leader position designated as a "Water Carrier (WC)". This is a business term and our version of a team leader–the difference is, a water carrier doesn't indicate prior experience or seniority. Water carriers mainly lead by organizing the group and planning meetings, but they need no experience–in fact, a water carrier's job may entail asking others to help with their expertise. The term water carrier is used for this reason–to decrease feelings of superiority/inferiority while maintaining a structure to the groups. For more information, please refer to this SOP. ==== Meetings ==== ===== During the Academic Year ===== UNC-CH HGAPS holds general "working" meetings on Thursday evenings from 6–8pm ET in a hybrid format utilizing the President's zoom and a designated meeting room on campus during the academic year. In the instance that the health of HGAPS members is put at risk by having in-person meetings, all meetings will occur via Zoom with no in person option available. The zoom links are sent in advance and you can sign up for weekly reminders through our Luma calendar. These meetings are working meetings, so during these two hours, members split into breakout rooms (in groups in person) to work with their teams. Attendance is taken via the RSVP sheet, an excel sheet sent out by the President each meeting. Each member is responsible for noting their attendance and whether they left early- for this reason, we recommend bookmarking the RSVP sheet. These meetings are typically outlined as follows: * Introduction: 6:00–6:15pm ** Members share how they are doing and any personal updates. Then, the Professor (Dr. Youngstrom in our case) or the President may give overall updates, such as different grant updates. This gives a chance for the President to organize breakout rooms. * Breakout rooms: 6:15–7:45pm ** Members work in their groups. At the end, the water carrier (see Project Teams above) notes the teams accomplishments on a Google Doc used by the President and Faculty Advisor to keep track of the team's accomplishments. * Report out: 7:45–8:00pm ** This is when each water carrier reports to the group what was accomplished and the Faculty Advisor gives final updates and/or announcements before concluding the meeting. Aside from the general working meetings, specific teams may choose to meet outside of the general meeting time, so there may be instances where teams meet at a different time. You may also see that these working meetings continue through school breaks–don't worry, those are optional for UNC students. ===== During the Summer ===== The HGAPS executive committee and other members who are highly involved throughout the course of the academic year may be given the opportunity to work as a paid, independent contractor over the summer, depending on the availability of funds and resources. If you are offered and accept this opportunity, you will be required to sign an Independent Contractor Agreement and fill out a W-9. Your scope of work will be determined before the summer and included in the Agreement. Summer workers can work on predetermined, funded projects for pay (other projects may be completed as volunteer work), though this is subject to change depending on the availability of funds. Payment will be administered on a monthly basis and should be received during the first week of the month for all paid work completed during the previous month (e.g., you will be paid for the work you completed from June 1st to June 30th during the first week of July). Contractors are responsible for tracking their hours worked on funded projects on the appropriate tab on the tracking sheet, include detailed descriptions of what project you worked on, what work was completed, and how many hours you worked (every 15 minutes counts, so you can track in 0.25 increments). Please be honest about how many hours you worked on a given projects and which projects you worked on (i.e., do not say that you worked on a funded project when you worked on an unfunded project); the research coordinator will check hours at the end of every month before sending payment. '''SUMMER 2022 (to be updated each year):''' HGAPS general meetings/editing sessions are held Thursday evenings from 6:00-8:00pm EST via Zoom. A member of the executive team will often send the RSVP sheet during the meetings via Zoom Chat so that attendance can be recorded. Within these meetings, the President will create breakout rooms based on specific projects that members can enter once prompted by the President. It is expected that each team creates an agenda and takes notes each meeting based on a predetermined [https://docs.google.com/document/d/1OXnGfmjrAqf5pVV_SSxRiK4399mdFvPoBoRaTeYrsJc/edit template]. The currently funded projects for Summer 2022 are Conferences, APS, SOPs, OToPS, Translations, Assessment Portfolios, Squid Game, Updating EBAs, Social Media, Speaker Series, Operations Manual, and Redcap; all other projects are done on a volunteer basis or may be funded in the future depending on acquisition of additional funds. ===== Editing Meetings (Edit-a-thons) ===== Edit-a-thons are specific HGAPS meetings in which clinicians, researchers, and other stakeholders are recruited to help edit HGAPS content and direct the club toward objectives that are pertinent to current issues in the field. We have had local clinicians, researchers, and organizations (e.g., [https://www.nami.org/Home NAMI]) attend in-person meetings and held teleconferences with other leaders in the field in the past. Edit-a-thons occur throughout the year and are organized by the executive team or an outreach coordinator designated specifically for edit-a-thon planning. They are typically held in larger spaces (e.g., the library) to accommodate extra guests and sometimes provide “special” food outside of the usual pizza. Visitors work alongside HGAPS members to view and edit content and make suggestions for other topics, projects, and edits. Edit-a-thons are a great opportunity to network with leaders in the field and show off your Wiki skills! To learn more, please refer to the [https://docs.google.com/document/d/1GzKFhpO694e4ai8FNtMLC2JGt7ffqqWdJ_-rL84gQ60/edit#heading=h.klvg718pd1zd Edit-a-thon SOP]. ==== Additional Opportunities for Members ==== ===== Wiki Authorship ===== HGAPS has recently begun turning Wiki pages into WikiJournal articles for publication. This is a great opportunity to add to your CV/resume and contribute to science in a meaningful way. We have learned that the best way to avoid hurt feelings is to be fully transparent about authorship. Dr. Youngstrom devised a system that fairly (or as fairly as possible, as these situations can be complicated) awards points toward authorship for different publication-related tasks. Please be sure to fill out an [https://docs.google.com/spreadsheets/d/12gh8mQHBxBzJUQSvu6wPmq1zSCOnhWcxceI61Z9G7Vw/edit#gid=1170307374 AARF] with your team if you are involved in a project that hopes to result in publication BEFORE you begin writing, or as early as possible in the process. You can reach out to Dr. Youngstrom or the graduate advisors if you are unsure about how to use the AARF. More details about submitting an article to a WikiJournal via HGAPS can be found in our [[Helping Give Away Psychological Science/Standard Operating Procedures/ Wiki Journal|WikiJournal Guide]]. ===== Conferences ===== HGAPS members have the opportunity to submit abstracts to and attend various conferences throughout the year. HGAPS tries to create opportunities to attend conferences by taking notes and helping students submit [[Helping Give Away Psychological Science/Standard Operating Procedures/Making a Poster|poster abstracts]]. Take a look at our tips for [[Helping Give Away Psychological Science/Standard Operating Procedures/Tips for Conference Attendance|attending conferences]] if you are considering submitting your own work or taking notes for HGAPS at an upcoming conference. Conferences occur throughout the year, and locations and dates vary by conference. Most conferences occur around the same time every year, though actual dates vary. Conference locations tend to shift each year. National conferences can take place anywhere in the United States, and international conferences may be anywhere across the globe. Conferences should have their own individual websites. Some of the conferences we frequent are [https://jccapfuturedirectionsforum.weebly.com/ Future Directions Forum], [https://ccf.fiu.edu/miami-international-child-adolescent-mental-health-conference/ Miami International Child & Adolescent Mental Health], [https://convention.apa.org/ American Psychological Association], and [https://www.abct.org/ Association Behavioral Cognitive Therapy]. == Onboarding Steps == Now that you know what you're joining, here are the steps you should follow in order to involve yourself in HGAPS as quickly and easily as possible. '''Step 1: Create a Wikipedia account and join the main means of communication.''' Before your first meeting, it’s helpful to at least have a Wikipedia account created. That way, if you’re interested in becoming a member, you can follow along with the page changes being made by the rest of your team members during the meetings. Read '''<u>Getting Step Up</u>''' on [[Helping_Give_Away_Psychological_Science/Standard_Operating_Procedures/_Getting_Started|this page]] to learn how create a Wikipedia account. Luckily, this will create a Wikiversity account too! '''Slack''' As for communication, for UNC-CH, we primarily use [https://slack.com/ Slack]. Slack is a business platform where people can easily message, @ each other and communicate with people through multiple channels and even an app. We recommend you download the app as to not miss important notifications. Although email reminders will still be sent for the Thursday working meeting, most meeting reminders, general information, and team specific announcements will be sent over Slack. In our Slack, the #general and #newmembers-[term] channels will be used for any meeting updates and important news. Project channels on the other hand will be used for project teams to communicate with each other, share resources with one another, and plan separate team meetings if necessary. To join, simply ask an executive member to add you to the general channel (it'll send you a time-limited invite) or ask your water carrier (WC) to add you into the necessary project channel. With all that in mind, go ahead and join to get connected with our team! '''Step 2: Attend your first meeting.''' As a new member, simply ask the President to stay behind or create a breakout room for new members–they’ll introduce you to the current projects, and you’ll have the opportunity to sit in and see if that project interests you! At that point, the water carrier will introduce you to the specifics and see what they can do about getting you up to speed as soon as possible. However, it's important to note that editing cannot be performed before completing the necessary trainings, so this introduction is just to help you understand the project's layout. * Tip: if you and your water carrier are unsure of where to start, ask them to share their screen and walk you through their slack channel and the project objectives and key results! At this point, if you would like to stay and are from UNC, please visit the [https://heellife.unc.edu/organization/hgaps heellife] page and request HGAPS membership. Once that is finished, if your project team is working on something you are not able to yet without completing wiki trainings, and you are given permission by your group's water carrier to do so during the meeting, you may move on to steps 3-4. '''Step 3: Create your accounts.''' HGAPS uses a variety of free platforms for different purposes as seen on the RSVP sheet. Two prominent examples are OSF and Zotero. used for uploading documents and creating citations, respectfully. Although not all projects require these accounts, it's good to have them in case a future project needs them. So make sure you: * Follow [https://osf.io/register?campaign=&next=&view_only= this link] to create an OSF and add it to your RSVP sheet. It's recommended to use a personal email to ensure access to the account after graduation. For more information on OSF, should you need it, follow this [[Helping Give Away Psychological Science/Standard Operating Procedures/ OSF Basics|link]]. * Follow [https://www.zotero.org/user/register this link] to create a Zotero and add it to your RSVP sheet. It's recommended to use a personal email to ensure access to the account after graduation. For more information on Zotero, should you need it, follow this [https://drive.google.com/file/d/1pfWLXd9cNVOLlCG0yydM_O8XWjUI4Osv/view?usp=sharing link]. * Ask your project if any other platforms are being used! For instance, Social Media frequently uses [https://www.canva.com/ Canva], an online graphic design platform. There, the leader must add the new user to a workgroup to work on the same project. So just ask and make sure you have everything you need! '''Step 4: Complete your trainings and report back.''' There are two trainings that must be complete in order to edit. These ensure your edits don't get removed by wiki. First training: Begin by completing the Wiki Training Modules here: https://dashboard.wikiedu.org/   * Sign in with your Wiki account. * Go to the "Training" tab. * Complete the "Student Training" Modules. * Make sure to finish the "Basics" and "Special Topics" sections! This should take about an hour or less. Ensure you're signed in so that your progress remains saved on your account. Second training: Complete the Wikipedia Adventure linked below. * Wikipedia:The Wikipedia Adventure * Ensure you have all 15 badges at the end! [[File:Userpageparroda.png|thumb|A standard Wiki User page where the user writes their major, mentor, and involvement in HGAPS.]] This training will take a bit longer, approximately an hour or a bit more. It includes music and details the layout of Wikipedia from within Wikipedia, guiding you on your first edits. At that point, go ahead and add some more information onto your user page- for example, go ahead and add HGAPS to your wiki profile (right). After this, you're all set with your trainings! Report back to your water carrier and to any HGAPS Exec member. An HGAPS Exec will then add you to HGAPS-relevant Wiki groups (including the HGAPS User Group and the HGAPS WikiEdu dashboard) while your water carrier will help you get more involved on their specific project. = Further information = === What if I have more questions? === Please reach out, we are here to help! HGAPS has a lot of exciting projects and components, and we know that getting started can seem overwhelming. Phoebe Rodda (UNC Chapter President) and Julia Bondareva (UNC Chapter Treasurer) are available through Slack for any questions. Dr. Youngstrom is as well, but as he is very busy we encourage you to direct questions that are not Eric-specific elsewhere first, if possible. === Who are the main HGAPS Exec that I will interact with? === * Eric Youngstrom, PhD (he/him) - HGAPS CEO, Founder and Faculty Advisor * Natalie Charamut (she/her) - HGAPS Assistant Executive Director '''(currently working on PhD, may not be very available but is very knowledgeable!)''' * Phoebe Rodda (she/her) - HGAPS UNC Chapter President * Julia Bondareva (they/them) - HGAPS UNC Chapter Treasurer * Maddie Gray (she/her) - HGAPS UNC Chapter Secretary * Thamasi Sagi (she/her) - HGAPS UNC Chapter Social Media Chair * Maggie Wong (she/her) - HGAPS UNC Chapter Past-President === Where can I find out more? === If you'd like more information about the history of HGAPS and different events you can be involved in through HGAPS, feel free to check out the HGAPS site linked [https://www.hgaps.org/ here], or this page of other [[Helping Give Away Psychological Science/Standard Operating Procedures|Standard Operating Procedures (SOPs)]]. Happy editing, we're glad to have you! h67ighabjno0rbtjpmafwbahkd0shj2 2413981 2413980 2022-08-12T15:21:01Z Ncharamut 2824970 /* Further information */ updated further information wikitext text/x-wiki = Onboarding with HGAPS = Welcome new member! So, you're interested in joining your university's chapter of HGAPS? This onboarding guide should help. Onboarding is the process of integrating a member into a group, in this case, the process of getting a new member integrated into HGAPS (particularly HGAPS at the University of North Carolina at Chapel Hill). This document explains how to become onboarded into HGAPS including what training needs to be completed and how to become a member of a project team. This is especially important for new members or current members preparing for new members on their team. '''''Please ensure all onboarding steps are complete!''''' = What is HGAPS? = Although many new members may already know of HGAPS and its goals, if you are a new member and do not, this section describes more about how the organization functions. === Background === Helping Give Away Psychological Science (HGAPS) began as a student-led organization at the University of North Carolina at Chapel Hill (UNC-CH) in 2016. Since then, the organization has grown into an officially recognized nonprofit and has incorporated chapters from across the U.S. including the University of Maryland, Appalachian State University, and the University of California, Los Angeles. ==== Goals ==== Our mission is to bridge the science-practice gap by collecting, distilling, and sharing psychological science to promote well-being in the community. To do this, HGAPS strives to disseminate evidence-based psychological information to those who need it most, creating better access to reliable science. This is done by creating small, project-focused groups within the organization that work together to consolidate and share evidence-based information and resources while collaborating with researchers and clinicians around the globe. We mostly do this through free platforms such as Wikiversity (Wikipedia’s sister site for research and learning materials), YouTube, Open Science Framework (OSF) and Zotero. By granting access to free and reliable resources for assessment, diagnosis, treatment, and prevention purposes, we can help clinics and researchers that lack funding and resources to access evidence-based practices. Overall, the hope is to create tools and trainings to help future generations of practitioners and researchers while educating the general public. === Membership in a University Chapter of HGAPS === ==== Requirements ==== In the university chapter, members are decided by the university's individual bylaws for student organizations and will abide by each university's individual policies for student organizations. For UNC-CH, students must be '''full-time''' '''undergraduate''' '''or graduate''' '''students'''. Members must attend 30% of meetings performed in a given semester after they have joined the club. This means that if you joined mid-semester, you only need to attend 30% of the meetings after you join. If you will be leaving early, arriving late, or are unable to attend a meeting, let your project team know as soon as you discover your attendance will be impacted. Attendance is taken by the HGAPS Secretary on the RSVP sheet. Dues must also be paid according to the amount set in a given semester/year–typically $12 per semester or $20 per year. These dues will be collected through the HGAPS PayPal account. Finally, '''all members must have wiki accounts and perform the necessary trainings before making any edits.''' Members intending on pursuing future leadership positions should try to attend most meetings and refer to this [[Helping Give Away Psychological Science/Standard Operating Procedures/Growth in HGAPS|page]]. ==== Communication Etiquette ==== Within the organization, communication largely occurs over Slack or email in-between meetings; however, we prefer HGAPS related communication occur over Slack when possible. Please respond to all forms of communication within '''24 hours''' (or by Monday morning if a message is sent over the weekend). If you are not able to fully respond to the content of the email, please reply to acknowledge that you have seen the email and give a timeframe for when you expect to be able to respond more thoroughly. If an email is sent to you directly, you are expected to reply unless otherwise noted (e.g., "Just FYI"); if you are in the CC line, a reply is not expected or required. If you will be away or unable to respond to email for an extended time period, an out of office message is useful to let others know not to expect a reply within the 24-hour timeframe. Replying to project leaders, faculty, grad student advisors, or other HGAPS team members is a great time to practice your email etiquette. If you are unsure how to professionally respond to an email, please let an advisor know as we would be happy to help you learn! Some basic rules include ALWAYS including a subject, a greeting, and a closing in your email, and making sure to use proper grammar and punctuation. Other suggestions include bolding, highlighting, or re-listing items requiring follow-up or action from the person you are emailing at the end of the email; taking the initiative on scheduling with others; and being clear about meeting/call times (e.g., "Our call is scheduled for this '''Thursday, 5/21, at 6:00pm EST.''' I look forward to our discussion!"). If you only require a response from one person, please message them directly rather than sending a message to the entire group. Before sending an email to the group, ask yourself if the topic is relevant to everyone, if email is the best medium for communicating that specific item (versus a Slack message or an in-person chat), and if the item can wait till the next meeting to discuss. We all receive a lot of emails and want to ensure we are not abusing the power to contact our team members instantly with a non-urgent question or comment. ==== Project Teams ==== HGAPS splits members into different project teams focusing on different tasks that aid in the dissemination of psychological research and resources. In the case of UNC–CH, projects are also enumerated, so 1022 equates to the team working on updating the Standard Operating Procedures (SOPs). Sometimes, these team goals may overlap, get passed between different teams, or end up involving more than one team at the same time. For instance, at UNC-CH the Translations team translates assessment measures into different languages for the Assessment Center team, and then the Social Media group could post their accomplishments on Twitter! Members may participate in more than one group, but during the school year, focusing on one is advisable (see Meetings below). Each group has a leader position designated as a "Water Carrier (WC)". This is a business term and our version of a team leader–the difference is, a water carrier doesn't indicate prior experience or seniority. Water carriers mainly lead by organizing the group and planning meetings, but they need no experience–in fact, a water carrier's job may entail asking others to help with their expertise. The term water carrier is used for this reason–to decrease feelings of superiority/inferiority while maintaining a structure to the groups. For more information, please refer to this SOP. ==== Meetings ==== ===== During the Academic Year ===== UNC-CH HGAPS holds general "working" meetings on Thursday evenings from 6–8pm ET in a hybrid format utilizing the President's zoom and a designated meeting room on campus during the academic year. In the instance that the health of HGAPS members is put at risk by having in-person meetings, all meetings will occur via Zoom with no in person option available. The zoom links are sent in advance and you can sign up for weekly reminders through our Luma calendar. These meetings are working meetings, so during these two hours, members split into breakout rooms (in groups in person) to work with their teams. Attendance is taken via the RSVP sheet, an excel sheet sent out by the President each meeting. Each member is responsible for noting their attendance and whether they left early- for this reason, we recommend bookmarking the RSVP sheet. These meetings are typically outlined as follows: * Introduction: 6:00–6:15pm ** Members share how they are doing and any personal updates. Then, the Professor (Dr. Youngstrom in our case) or the President may give overall updates, such as different grant updates. This gives a chance for the President to organize breakout rooms. * Breakout rooms: 6:15–7:45pm ** Members work in their groups. At the end, the water carrier (see Project Teams above) notes the teams accomplishments on a Google Doc used by the President and Faculty Advisor to keep track of the team's accomplishments. * Report out: 7:45–8:00pm ** This is when each water carrier reports to the group what was accomplished and the Faculty Advisor gives final updates and/or announcements before concluding the meeting. Aside from the general working meetings, specific teams may choose to meet outside of the general meeting time, so there may be instances where teams meet at a different time. You may also see that these working meetings continue through school breaks–don't worry, those are optional for UNC students. ===== During the Summer ===== The HGAPS executive committee and other members who are highly involved throughout the course of the academic year may be given the opportunity to work as a paid, independent contractor over the summer, depending on the availability of funds and resources. If you are offered and accept this opportunity, you will be required to sign an Independent Contractor Agreement and fill out a W-9. Your scope of work will be determined before the summer and included in the Agreement. Summer workers can work on predetermined, funded projects for pay (other projects may be completed as volunteer work), though this is subject to change depending on the availability of funds. Payment will be administered on a monthly basis and should be received during the first week of the month for all paid work completed during the previous month (e.g., you will be paid for the work you completed from June 1st to June 30th during the first week of July). Contractors are responsible for tracking their hours worked on funded projects on the appropriate tab on the tracking sheet, include detailed descriptions of what project you worked on, what work was completed, and how many hours you worked (every 15 minutes counts, so you can track in 0.25 increments). Please be honest about how many hours you worked on a given projects and which projects you worked on (i.e., do not say that you worked on a funded project when you worked on an unfunded project); the research coordinator will check hours at the end of every month before sending payment. '''SUMMER 2022 (to be updated each year):''' HGAPS general meetings/editing sessions are held Thursday evenings from 6:00-8:00pm EST via Zoom. A member of the executive team will often send the RSVP sheet during the meetings via Zoom Chat so that attendance can be recorded. Within these meetings, the President will create breakout rooms based on specific projects that members can enter once prompted by the President. It is expected that each team creates an agenda and takes notes each meeting based on a predetermined [https://docs.google.com/document/d/1OXnGfmjrAqf5pVV_SSxRiK4399mdFvPoBoRaTeYrsJc/edit template]. The currently funded projects for Summer 2022 are Conferences, APS, SOPs, OToPS, Translations, Assessment Portfolios, Squid Game, Updating EBAs, Social Media, Speaker Series, Operations Manual, and Redcap; all other projects are done on a volunteer basis or may be funded in the future depending on acquisition of additional funds. ===== Editing Meetings (Edit-a-thons) ===== Edit-a-thons are specific HGAPS meetings in which clinicians, researchers, and other stakeholders are recruited to help edit HGAPS content and direct the club toward objectives that are pertinent to current issues in the field. We have had local clinicians, researchers, and organizations (e.g., [https://www.nami.org/Home NAMI]) attend in-person meetings and held teleconferences with other leaders in the field in the past. Edit-a-thons occur throughout the year and are organized by the executive team or an outreach coordinator designated specifically for edit-a-thon planning. They are typically held in larger spaces (e.g., the library) to accommodate extra guests and sometimes provide “special” food outside of the usual pizza. Visitors work alongside HGAPS members to view and edit content and make suggestions for other topics, projects, and edits. Edit-a-thons are a great opportunity to network with leaders in the field and show off your Wiki skills! To learn more, please refer to the [https://docs.google.com/document/d/1GzKFhpO694e4ai8FNtMLC2JGt7ffqqWdJ_-rL84gQ60/edit#heading=h.klvg718pd1zd Edit-a-thon SOP]. ==== Additional Opportunities for Members ==== ===== Wiki Authorship ===== HGAPS has recently begun turning Wiki pages into WikiJournal articles for publication. This is a great opportunity to add to your CV/resume and contribute to science in a meaningful way. We have learned that the best way to avoid hurt feelings is to be fully transparent about authorship. Dr. Youngstrom devised a system that fairly (or as fairly as possible, as these situations can be complicated) awards points toward authorship for different publication-related tasks. Please be sure to fill out an [https://docs.google.com/spreadsheets/d/12gh8mQHBxBzJUQSvu6wPmq1zSCOnhWcxceI61Z9G7Vw/edit#gid=1170307374 AARF] with your team if you are involved in a project that hopes to result in publication BEFORE you begin writing, or as early as possible in the process. You can reach out to Dr. Youngstrom or the graduate advisors if you are unsure about how to use the AARF. More details about submitting an article to a WikiJournal via HGAPS can be found in our [[Helping Give Away Psychological Science/Standard Operating Procedures/ Wiki Journal|WikiJournal Guide]]. ===== Conferences ===== HGAPS members have the opportunity to submit abstracts to and attend various conferences throughout the year. HGAPS tries to create opportunities to attend conferences by taking notes and helping students submit [[Helping Give Away Psychological Science/Standard Operating Procedures/Making a Poster|poster abstracts]]. Take a look at our tips for [[Helping Give Away Psychological Science/Standard Operating Procedures/Tips for Conference Attendance|attending conferences]] if you are considering submitting your own work or taking notes for HGAPS at an upcoming conference. Conferences occur throughout the year, and locations and dates vary by conference. Most conferences occur around the same time every year, though actual dates vary. Conference locations tend to shift each year. National conferences can take place anywhere in the United States, and international conferences may be anywhere across the globe. Conferences should have their own individual websites. Some of the conferences we frequent are [https://jccapfuturedirectionsforum.weebly.com/ Future Directions Forum], [https://ccf.fiu.edu/miami-international-child-adolescent-mental-health-conference/ Miami International Child & Adolescent Mental Health], [https://convention.apa.org/ American Psychological Association], and [https://www.abct.org/ Association Behavioral Cognitive Therapy]. == Onboarding Steps == Now that you know what you're joining, here are the steps you should follow in order to involve yourself in HGAPS as quickly and easily as possible. '''Step 1: Create a Wikipedia account and join the main means of communication.''' Before your first meeting, it’s helpful to at least have a Wikipedia account created. That way, if you’re interested in becoming a member, you can follow along with the page changes being made by the rest of your team members during the meetings. Read '''<u>Getting Step Up</u>''' on [[Helping_Give_Away_Psychological_Science/Standard_Operating_Procedures/_Getting_Started|this page]] to learn how create a Wikipedia account. Luckily, this will create a Wikiversity account too! '''Slack''' As for communication, for UNC-CH, we primarily use [https://slack.com/ Slack]. Slack is a business platform where people can easily message, @ each other and communicate with people through multiple channels and even an app. We recommend you download the app as to not miss important notifications. Although email reminders will still be sent for the Thursday working meeting, most meeting reminders, general information, and team specific announcements will be sent over Slack. In our Slack, the #general and #newmembers-[term] channels will be used for any meeting updates and important news. Project channels on the other hand will be used for project teams to communicate with each other, share resources with one another, and plan separate team meetings if necessary. To join, simply ask an executive member to add you to the general channel (it'll send you a time-limited invite) or ask your water carrier (WC) to add you into the necessary project channel. With all that in mind, go ahead and join to get connected with our team! '''Step 2: Attend your first meeting.''' As a new member, simply ask the President to stay behind or create a breakout room for new members–they’ll introduce you to the current projects, and you’ll have the opportunity to sit in and see if that project interests you! At that point, the water carrier will introduce you to the specifics and see what they can do about getting you up to speed as soon as possible. However, it's important to note that editing cannot be performed before completing the necessary trainings, so this introduction is just to help you understand the project's layout. * Tip: if you and your water carrier are unsure of where to start, ask them to share their screen and walk you through their slack channel and the project objectives and key results! At this point, if you would like to stay and are from UNC, please visit the [https://heellife.unc.edu/organization/hgaps heellife] page and request HGAPS membership. Once that is finished, if your project team is working on something you are not able to yet without completing wiki trainings, and you are given permission by your group's water carrier to do so during the meeting, you may move on to steps 3-4. '''Step 3: Create your accounts.''' HGAPS uses a variety of free platforms for different purposes as seen on the RSVP sheet. Two prominent examples are OSF and Zotero. used for uploading documents and creating citations, respectfully. Although not all projects require these accounts, it's good to have them in case a future project needs them. So make sure you: * Follow [https://osf.io/register?campaign=&next=&view_only= this link] to create an OSF and add it to your RSVP sheet. It's recommended to use a personal email to ensure access to the account after graduation. For more information on OSF, should you need it, follow this [[Helping Give Away Psychological Science/Standard Operating Procedures/ OSF Basics|link]]. * Follow [https://www.zotero.org/user/register this link] to create a Zotero and add it to your RSVP sheet. It's recommended to use a personal email to ensure access to the account after graduation. For more information on Zotero, should you need it, follow this [https://drive.google.com/file/d/1pfWLXd9cNVOLlCG0yydM_O8XWjUI4Osv/view?usp=sharing link]. * Ask your project if any other platforms are being used! For instance, Social Media frequently uses [https://www.canva.com/ Canva], an online graphic design platform. There, the leader must add the new user to a workgroup to work on the same project. So just ask and make sure you have everything you need! '''Step 4: Complete your trainings and report back.''' There are two trainings that must be complete in order to edit. These ensure your edits don't get removed by wiki. First training: Begin by completing the Wiki Training Modules here: https://dashboard.wikiedu.org/   * Sign in with your Wiki account. * Go to the "Training" tab. * Complete the "Student Training" Modules. * Make sure to finish the "Basics" and "Special Topics" sections! This should take about an hour or less. Ensure you're signed in so that your progress remains saved on your account. Second training: Complete the Wikipedia Adventure linked below. * Wikipedia:The Wikipedia Adventure * Ensure you have all 15 badges at the end! [[File:Userpageparroda.png|thumb|A standard Wiki User page where the user writes their major, mentor, and involvement in HGAPS.]] This training will take a bit longer, approximately an hour or a bit more. It includes music and details the layout of Wikipedia from within Wikipedia, guiding you on your first edits. At that point, go ahead and add some more information onto your user page- for example, go ahead and add HGAPS to your wiki profile (right). After this, you're all set with your trainings! Report back to your water carrier and to any HGAPS Exec member. An HGAPS Exec will then add you to HGAPS-relevant Wiki groups (including the HGAPS User Group and the HGAPS WikiEdu dashboard) while your water carrier will help you get more involved on their specific project. = Further information = === What if I have more questions? === Please reach out, we are here to help! HGAPS has a lot of exciting projects and components, and we know that getting started can seem overwhelming. If you have any questions, please reach out to the leadership in your chapter (past president, president, treasurer, secretary, etc.).You may reach out to your faculty advisor; however they are typically very busy, so we encourage you to direct questions that are not specific to the advisor elsewhere first, if possible. === Who are the main HGAPS Exec that I will interact with? === ==== UNC Chapter ==== * Eric Youngstrom, PhD (he/him) - HGAPS CEO, Founder and Faculty Advisor * Natalie Charamut (she/her) - HGAPS Assistant Executive Director '''(currently working on PhD, may not be very available but is very knowledgeable!)''' * Phoebe Rodda (she/her) - HGAPS UNC Chapter President * Julia Bondareva (they/them) - HGAPS UNC Chapter Treasurer * Maddie Gray (she/her) - HGAPS UNC Chapter Secretary * Thamasi Sagi (she/her) - HGAPS UNC Chapter Social Media Chair * Maggie Wong (she/her) - HGAPS UNC Chapter Past-President === Where can I find out more? === If you'd like more information about the history of HGAPS and different events you can be involved in through HGAPS, feel free to check out the HGAPS site linked [https://www.hgaps.org/ here], or this page of other [[Helping Give Away Psychological Science/Standard Operating Procedures|Standard Operating Procedures (SOPs)]]. Happy editing, we're glad to have you! k4z7ua9z15zwrdncnjsmqk5nq38tza2 0 285380 2413959 2413335 2022-08-12T14:05:33Z Young1lim 21186 /* Handling Series of Data */ wikitext text/x-wiki === Introduction === * Overview ([[Media:C01.Intro1.Overview.1.A.20170925.pdf |A.pdf]], [[Media:C01.Intro1.Overview.1.B.20170901.pdf |B.pdf]], [[Media:C01.Intro1.Overview.1.C.20170904.pdf |C.pdf]]) * Number System ([[Media:C01.Intro2.Number.1.A.20171023.pdf |A.pdf]], [[Media:C01.Intro2.Number.1.B.20170909.pdf |B.pdf]], [[Media:C01.Intro2.Number.1.C.20170914.pdf |C.pdf]]) * Memory System ([[Media:C01.Intro2.Memory.1.A.20170907.pdf |A.pdf]], [[Media:C01.Intro3.Memory.1.B.20170909.pdf |B.pdf]], [[Media:C01.Intro3.Memory.1.C.20170914.pdf |C.pdf]]) === Handling Repetition === * Control ([[Media:C02.Repeat1.Control.1.A.20170925.pdf |A.pdf]], [[Media:C02.Repeat1.Control.1.B.20170918.pdf |B.pdf]], [[Media:C02.Repeat1.Control.1.C.20170926.pdf |C.pdf]]) * Loop ([[Media:C02.Repeat2.Loop.1.A.20170925.pdf |A.pdf]], [[Media:C02.Repeat2.Loop.1.B.20170918.pdf |B.pdf]]) === Handling a Big Work === * Function Overview ([[Media:C03.Func1.Overview.1.A.20171030.pdf |A.pdf]], [[Media:C03.Func1.Oerview.1.B.20161022.pdf |B.pdf]]) * Functions & Variables ([[Media:C03.Func2.Variable.1.A.20161222.pdf |A.pdf]], [[Media:C03.Func2.Variable.1.B.20161222.pdf |B.pdf]]) * Functions & Pointers ([[Media:C03.Func3.Pointer.1.A.20161122.pdf |A.pdf]], [[Media:C03.Func3.Pointer.1.B.20161122.pdf |B.pdf]]) * Functions & Recursions ([[Media:C03.Func4.Recursion.1.A.20161214.pdf |A.pdf]], [[Media:C03.Func4.Recursion.1.B.20161214.pdf |B.pdf]]) === Handling Series of Data === ==== Background ==== * Background ([[Media:C04.Series0.Background.1.A.20180727.pdf |A.pdf]]) ==== Basics ==== * Arrays ([[Media:C04.Series1.Array.1.A.20220811.pdf |A.pdf]], [[Media:C04.Series1.Array.1.B.20161115.pdf |B.pdf]]) * Pointers ([[Media:C04.Series2.Pointer.1.A.20180726.pdf |A.pdf]], [[Media:C04.Series2.Pointer.1.B.20161115.pdf |B.pdf]]) * Array Pointers ([[Media:C04.Series3.ArrayPointer.1.A.20220811.pdf |A.pdf]], [[Media:C04.Series3.ArrayPointer.1.B.20181203.pdf |B.pdf]]) * Multi-dimensional Arrays ([[Media:C04.Series4.MultiDim.1.A.20220418.pdf |A.pdf]], [[Media:C04.Series4.MultiDim.1.B.11.pdf |B.pdf]]) * Array Access Methods ([[Media:C04.Series4.ArrayAccess.1.A.20190511.pdf |A.pdf]], [[Media:C04.Series3.ArrayPointer.1.B.20181203.pdf |B.pdf]]) * Structures ([[Media:C04.Series3.Structure.1.A.20171204.pdf |A.pdf]], [[Media:C04.Series2.Structure.1.B.20161130.pdf |B.pdf]]) ==== Applications ==== * Applications of Arrays ([[Media:C04.Series1App.Array.1.A.20220811.pdf |A.pdf]]) * Applications of Pointers ([[Media:C04.Series7.AppPoint.1.A.20200424.pdf |A.pdf]]) * Applications of Array Pointers ([[Media:C04.Series3App.ArrayPointer.1.A.2022024.pdf |A.pdf]]) * Applications of Multi-dimensional Arrays ([[Media:C04.Series4App.MultiDim.1.A.20210719.pdf |A.pdf]]) * Applications of Array Access Methods ([[Media:C04.Series9.AppArrAcess.1.A.20190511.pdf |A.pdf]]) * Applications of Structures ([[Media:C04.Series6.AppStruct.1.A.20190423.pdf |A.pdf]]) ==== Examples ==== * Spreadsheet Example Programs :: Example 1 ([[Media:C04.Series7.Example.1.A.20171213.pdf |A.pdf]], [[Media:C04.Series7.Example.1.C.20171213.pdf |C.pdf]]) :: Example 2 ([[Media:C04.Series7.Example.2.A.20171213.pdf |A.pdf]], [[Media:C04.Series7.Example.2.C.20171213.pdf |C.pdf]]) :: Example 3 ([[Media:C04.Series7.Example.3.A.20171213.pdf |A.pdf]], [[Media:C04.Series7.Example.3.C.20171213.pdf |C.pdf]]) :: Bubble Sort ([[Media:C04.Series7.BubbleSort.1.A.20171211.pdf |A.pdf]]) === Handling Various Kinds of Data === * Types ([[Media:C05.Data1.Type.1.A.20180217.pdf |A.pdf]], [[Media:C05.Data1.Type.1.B.20161212.pdf |B.pdf]]) * Typecasts ([[Media:C05.Data2.TypeCast.1.A.20180217.pdf |A.pdf]], [[Media:C05.Data2.TypeCast.1.B.20161216.pdf |A.pdf]]) * Operators ([[Media:C05.Data3.Operators.1.A.20161219.pdf |A.pdf]], [[Media:C05.Data3.Operators.1.B.20161216.pdf |B.pdf]]) * Files ([[Media:C05.Data4.File.1.A.20161124.pdf |A.pdf]], [[Media:C05.Data4.File.1.B.20161212.pdf |B.pdf]]) === Handling Low Level Operations === * Bitwise Operations ([[Media:BitOp.1.B.20161214.pdf |A.pdf]], [[Media:BitOp.1.B.20161203.pdf |B.pdf]]) * Bit Field ([[Media:BitField.1.A.20161214.pdf |A.pdf]], [[Media:BitField.1.B.20161202.pdf |B.pdf]]) * Union ([[Media:Union.1.A.20161221.pdf |A.pdf]], [[Media:Union.1.B.20161111.pdf |B.pdf]]) * Accessing IO Registers ([[Media:IO.1.A.20141215.pdf |A.pdf]], [[Media:IO.1.B.20161217.pdf |B.pdf]]) === Declarations === * Type Specifiers and Qualifiers ([[Media:C07.Spec1.Type.1.A.20171004.pdf |pdf]]) * Storage Class Specifiers ([[Media:C07.Spec2.Storage.1.A.20171009.pdf |pdf]]) * Scope === Class Notes === * TOC ([[Media:TOC.20171007.pdf |TOC.pdf]]) * Day01 ([[Media:Day01.A.20171007.pdf |A.pdf]], [[Media:Day01.B.20171209.pdf |B.pdf]], [[Media:Day01.C.20171211.pdf |C.pdf]]) ...... Introduction (1) Standard Library * Day02 ([[Media:Day02.A.20171007.pdf |A.pdf]], [[Media:Day02.B.20171209.pdf |B.pdf]], [[Media:Day02.C.20171209.pdf |C.pdf]]) ...... Introduction (2) Basic Elements * Day03 ([[Media:Day03.A.20171007.pdf |A.pdf]], [[Media:Day03.B.20170908.pdf |B.pdf]], [[Media:Day03.C.20171209.pdf |C.pdf]]) ...... Introduction (3) Numbers * Day04 ([[Media:Day04.A.20171007.pdf |A.pdf]], [[Media:Day04.B.20170915.pdf |B.pdf]], [[Media:Day04.C.20171209.pdf |C.pdf]]) ...... Structured Programming (1) Flowcharts * Day05 ([[Media:Day05.A.20171007.pdf |A.pdf]], [[Media:Day05.B.20170915.pdf |B.pdf]], [[Media:Day05.C.20171209.pdf |C.pdf]]) ...... Structured Programming (2) Conditions and Loops * Day06 ([[Media:Day06.A.20171007.pdf |A.pdf]], [[Media:Day06.B.20170923.pdf |B.pdf]], [[Media:Day06.C.20171209.pdf |C.pdf]]) ...... Program Control * Day07 ([[Media:Day07.A.20171007.pdf |A.pdf]], [[Media:Day07.B.20170926.pdf |B.pdf]], [[Media:Day07.C.20171209.pdf |C.pdf]]) ...... Function (1) Definitions * Day08 ([[Media:Day08.A.20171028.pdf |A.pdf]], [[Media:Day08.B.20171016.pdf |B.pdf]], [[Media:Day08.C.20171209.pdf |C.pdf]]) ...... Function (2) Storage Class and Scope * Day09 ([[Media:Day09.A.20171007.pdf |A.pdf]], [[Media:Day09.B.20171017.pdf |B.pdf]], [[Media:Day09.C.20171209.pdf |C.pdf]]) ...... Function (3) Recursion * Day10 ([[Media:Day10.A.20171209.pdf |A.pdf]], [[Media:Day10.B.20171017.pdf |B.pdf]], [[Media:Day10.C.20171209.pdf |C.pdf]]) ...... Arrays (1) Definitions * Day11 ([[Media:Day11.A.20171024.pdf |A.pdf]], [[Media:Day11.B.20171017.pdf |B.pdf]], [[Media:Day11.C.20171212.pdf |C.pdf]]) ...... Arrays (2) Applications * Day12 ([[Media:Day12.A.20171024.pdf |A.pdf]], [[Media:Day12.B.20171020.pdf |B.pdf]], [[Media:Day12.C.20171209.pdf |C.pdf]]) ...... Pointers (1) Definitions * Day13 ([[Media:Day13.A.20171025.pdf |A.pdf]], [[Media:Day13.B.20171024.pdf |B.pdf]], [[Media:Day13.C.20171209.pdf |C.pdf]]) ...... Pointers (2) Applications * Day14 ([[Media:Day14.A.20171226.pdf |A.pdf]], [[Media:Day14.B.20171101.pdf |B.pdf]], [[Media:Day14.C.20171209.pdf |C.pdf]]) ...... C String (1) * Day15 ([[Media:Day15.A.20171209.pdf |A.pdf]], [[Media:Day15.B.20171124.pdf |B.pdf]], [[Media:Day15.C.20171209.pdf |C.pdf]]) ...... C String (2) * Day16 ([[Media:Day16.A.20171208.pdf |A.pdf]], [[Media:Day16.B.20171114.pdf |B.pdf]], [[Media:Day16.C.20171209.pdf |C.pdf]]) ...... C Formatted IO * Day17 ([[Media:Day17.A.20171031.pdf |A.pdf]], [[Media:Day17.B.20171111.pdf |B.pdf]], [[Media:Day17.C.20171209.pdf |C.pdf]]) ...... Structure (1) Definitions * Day18 ([[Media:Day18.A.20171206.pdf |A.pdf]], [[Media:Day18.B.20171128.pdf |B.pdf]], [[Media:Day18.C.20171212.pdf |C.pdf]]) ...... Structure (2) Applications * Day19 ([[Media:Day19.A.20171205.pdf |A.pdf]], [[Media:Day19.B.20171121.pdf |B.pdf]], [[Media:Day19.C.20171209.pdf |C.pdf]]) ...... Union, Bitwise Operators, Enum * Day20 ([[Media:Day20.A.20171205.pdf |A.pdf]], [[Media:Day20.B.20171201.pdf |B.pdf]], [[Media:Day20.C.20171212.pdf |C.pdf]]) ...... Linked List * Day21 ([[Media:Day21.A.20171206.pdf |A.pdf]], [[Media:Day21.B.20171208.pdf |B.pdf]], [[Media:Day21.C.20171212.pdf |C.pdf]]) ...... File Processing * Day22 ([[Media:Day22.A.20171212.pdf |A.pdf]], [[Media:Day22.B.20171213.pdf |B.pdf]], [[Media:Day22.C.20171212.pdf |C.pdf]]) ...... Preprocessing <!----------------------------------------------------------------------> </br> See also https://cprogramex.wordpress.com/ == '''Old Materials '''== until 201201 * Intro.Overview.1.A ([[Media:C.Intro.Overview.1.A.20120107.pdf |pdf]]) * Intro.Memory.1.A ([[Media:C.Intro.Memory.1.A.20120107.pdf |pdf]]) * Intro.Number.1.A ([[Media:C.Intro.Number.1.A.20120107.pdf |pdf]]) * Repeat.Control.1.A ([[Media:C.Repeat.Control.1.A.20120109.pdf |pdf]]) * Repeat.Loop.1.A ([[Media:C.Repeat.Loop.1.A.20120113.pdf |pdf]]) * Work.Function.1.A ([[Media:C.Work.Function.1.A.20120117.pdf |pdf]]) * Work.Scope.1.A ([[Media:C.Work.Scope.1.A.20120117.pdf |pdf]]) * Series.Array.1.A ([[Media:Series.Array.1.A.20110718.pdf |pdf]]) * Series.Pointer.1.A ([[Media:Series.Pointer.1.A.20110719.pdf |pdf]]) * Series.Structure.1.A ([[Media:Series.Structure.1.A.20110805.pdf |pdf]]) * Data.Type.1.A ([[Media:C05.Data2.TypeCast.1.A.20130813.pdf |pdf]]) * Data.TypeCast.1.A ([[Media:Data.TypeCast.1.A.pdf |pdf]]) * Data.Operators.1.A ([[Media:Data.Operators.1.A.20110712.pdf |pdf]]) <br> until 201107 * Intro.1.A ([[Media:Intro.1.A.pdf |pdf]]) * Control.1.A ([[Media:Control.1.A.20110706.pdf |pdf]]) * Iteration.1.A ([[Media:Iteration.1.A.pdf |pdf]]) * Function.1.A ([[Media:Function.1.A.20110705.pdf |pdf]]) * Variable.1.A ([[Media:Variable.1.A.20110708.pdf |pdf]]) * Operators.1.A ([[Media:Operators.1.A.20110712.pdf |pdf]]) * Pointer.1.A ([[Media:Pointer.1.A.pdf |pdf]]) * Pointer.2.A ([[Media:Pointer.2.A.pdf |pdf]]) * Array.1.A ([[Media:Array.1.A.pdf |pdf]]) * Type.1.A ([[Media:Type.1.A.pdf |pdf]]) * Structure.1.A ([[Media:Structure.1.A.pdf |pdf]]) go to [ [[C programming in plain view]] ] [[Category:C programming]] </br> 07j01p6r82onbsw56lgsshzldmw0ehz 0 285384 2414045 2413939 2022-08-13T07:51:40Z Young1lim 21186 /* Workings of the GNU Compiler */ wikitext text/x-wiki === Workings of the GNU Compiler === * Overview ([[Media:Overview.20200211.pdf |pdf]]) * Access ([[Media:Access.20200409.pdf |pdf]]) * Operators ([[Media:Operator.20200427.pdf |pdf]]) * Conditions ([[Media:Condition.20220811.pdf |pdf]]) * Control ([[Media:Control.20220616.pdf |pdf]]) * Procedure ([[Media:Procedure.20220412.pdf |pdf]]) * Recursion ([[Media:Recursion.20210824-2.pdf |pdf]]) * Arrays ([[Media:Array.20211018.pdf |pdf]]) * Structures ([[Media:Structure.20220101.pdf |pdf]]) * Alignment ([[Media:Alignment.20201117.pdf |pdf]]) * Pointers ([[Media:Pointer.20201106.pdf |pdf]]) </br> === Workings of the GNU Linker === ==== Overview ==== * Static Linking Overview ([[Media:Link.1.StaticOverview.20181120.pdf |pdf]]) * Dynamic Linking Overview ([[Media:Link.2.DynamicOverview.20181120.pdf |pdf]]) ==== Linking Process ==== * Object Files ([[Media:Link.3.A.Object.20190121.pdf |A.pdf]], [[Media:Link.3.B.Object.20190405.pdf |B.pdf]]) * Symbols ([[Media:Link.4.A.Symbol.20190312.pdf |A.pdf]], [[Media:Link.4.B.Symbol.20190312.pdf |B.pdf]]) * Relocation ([[Media:Link.5.A.Relocation.20190320.pdf |A.pdf]], [[Media:Link.5.B.Relocation.20190322.pdf |B.pdf]]) * Loading ([[Media:Link.6.A.Loading.20190501.pdf |A.pdf]], [[Media:Link.6.B.Loading.20190126.pdf |B.pdf]]) * Static Linking ([[Media:Link.7.A.StaticLink.20190122.pdf |A.pdf]], [[Media:Link.7.B.StaticLink.20190128.pdf |B.pdf]]) * Dynamic Linking ([[Media:Link.8.A.DynamicLink.20190207.pdf |A.pdf]], [[Media:Link.8.B.DynamicLink.20190209.pdf |B.pdf]]) * Position Independent Code ([[Media:Link.9.A.PIC.20190304.pdf |A.pdf]], [[Media:Link.9.B.PIC.20190309.pdf |B.pdf]]) ==== Example I ==== * Vector addition ([[Media:Eg1.1A.Vector.20190121.pdf |A.pdf]], [[Media:Eg1.1B.Vector.20190121.pdf |B.pdf]]) * Swapping array elements ([[Media:Eg1.2A.Swap.20190302.pdf |A.pdf]], [[Media:Eg1.2B.Swap.20190121.pdf |B.pdf]]) * Nested functions ([[Media:Eg1.3A.Nest.20190121.pdf |A.pdf]], [[Media:Eg1.3B.Nest.20190121.pdf |B.pdf]]) ==== Examples II ==== * analysis of static linking ([[Media:Ex1.A.StaticLinkEx.20190121.pdf |A.pdf]], [[Media:Ex2.B.StaticLinkEx.20190121.pdf |B.pdf]]) * analysis of dynamic linking ([[Media:Ex2.A.DynamicLinkEx.20190121.pdf |A.pdf]]) * analysis of PIC ([[Media:Ex3.A.PICEx.20190121.pdf |A.pdf]]) </br> go to [ [[C programming in plain view]] ] [[Category:C programming]] hd0avl0e1rnum1581ok42vmj2gfi6z9 2414047 2414045 2022-08-13T07:53:20Z Young1lim 21186 /* Workings of the GNU Compiler */ wikitext text/x-wiki === Workings of the GNU Compiler === * Overview ([[Media:Overview.20200211.pdf |pdf]]) * Access ([[Media:Access.20200409.pdf |pdf]]) * Operators ([[Media:Operator.20200427.pdf |pdf]]) * Conditions ([[Media:Condition.20220812.pdf |pdf]]) * Control ([[Media:Control.20220616.pdf |pdf]]) * Procedure ([[Media:Procedure.20220412.pdf |pdf]]) * Recursion ([[Media:Recursion.20210824-2.pdf |pdf]]) * Arrays ([[Media:Array.20211018.pdf |pdf]]) * Structures ([[Media:Structure.20220101.pdf |pdf]]) * Alignment ([[Media:Alignment.20201117.pdf |pdf]]) * Pointers ([[Media:Pointer.20201106.pdf |pdf]]) </br> === Workings of the GNU Linker === ==== Overview ==== * Static Linking Overview ([[Media:Link.1.StaticOverview.20181120.pdf |pdf]]) * Dynamic Linking Overview ([[Media:Link.2.DynamicOverview.20181120.pdf |pdf]]) ==== Linking Process ==== * Object Files ([[Media:Link.3.A.Object.20190121.pdf |A.pdf]], [[Media:Link.3.B.Object.20190405.pdf |B.pdf]]) * Symbols ([[Media:Link.4.A.Symbol.20190312.pdf |A.pdf]], [[Media:Link.4.B.Symbol.20190312.pdf |B.pdf]]) * Relocation ([[Media:Link.5.A.Relocation.20190320.pdf |A.pdf]], [[Media:Link.5.B.Relocation.20190322.pdf |B.pdf]]) * Loading ([[Media:Link.6.A.Loading.20190501.pdf |A.pdf]], [[Media:Link.6.B.Loading.20190126.pdf |B.pdf]]) * Static Linking ([[Media:Link.7.A.StaticLink.20190122.pdf |A.pdf]], [[Media:Link.7.B.StaticLink.20190128.pdf |B.pdf]]) * Dynamic Linking ([[Media:Link.8.A.DynamicLink.20190207.pdf |A.pdf]], [[Media:Link.8.B.DynamicLink.20190209.pdf |B.pdf]]) * Position Independent Code ([[Media:Link.9.A.PIC.20190304.pdf |A.pdf]], [[Media:Link.9.B.PIC.20190309.pdf |B.pdf]]) ==== Example I ==== * Vector addition ([[Media:Eg1.1A.Vector.20190121.pdf |A.pdf]], [[Media:Eg1.1B.Vector.20190121.pdf |B.pdf]]) * Swapping array elements ([[Media:Eg1.2A.Swap.20190302.pdf |A.pdf]], [[Media:Eg1.2B.Swap.20190121.pdf |B.pdf]]) * Nested functions ([[Media:Eg1.3A.Nest.20190121.pdf |A.pdf]], [[Media:Eg1.3B.Nest.20190121.pdf |B.pdf]]) ==== Examples II ==== * analysis of static linking ([[Media:Ex1.A.StaticLinkEx.20190121.pdf |A.pdf]], [[Media:Ex2.B.StaticLinkEx.20190121.pdf |B.pdf]]) * analysis of dynamic linking ([[Media:Ex2.A.DynamicLinkEx.20190121.pdf |A.pdf]]) * analysis of PIC ([[Media:Ex3.A.PICEx.20190121.pdf |A.pdf]]) </br> go to [ [[C programming in plain view]] ] [[Category:C programming]] 4hhfcfdo8228z7rwxi61wlzkqz7stm4 0 285385 2414070 2413317 2022-08-13T10:23:36Z Young1lim 21186 /* Object Files */ wikitext text/x-wiki === Executable and Linkable Format === ==== Object Files ==== * Introduction * ELF Header ([[Media:ELF1.1B.Header.20220211.pdf |pdf]]) * Group section ([[Media:ELF1.1C.Group.20220426.pdf |pdf]]) * String table section ([[Media:ELF1.1D.StringTbl.20220427.pdf |pdf]]) * Weak and common symbols ([[Media:ELF1.1E.WeakComm.20220810.pdf |pdf]]) * Symbol table section ([[Media:ELF1.1F.SymbolTbl.20220722.pdf |pdf]]) * Special Sections ([[Media:ELF1.7B.Section.20200511.pdf |B.pdf]]) * Relocation ([[Media:ELF1.6A.Relocation.20190413.pdf |A.pdf]]) ==== Program Loading and Dynamic Linking ==== * Introduction * Program Header ([[Media:ELF1.2B.ProgHeader.20220110.pdf |pdf]]) * Program Loading * Dynamic Linking ([[Media:ELF2.4A.DynLinking.20191028.pdf |pdf]]) ==== C Library ==== * C Library === ELF Study === ==== ELF Relocations ==== * Linking ([[Media:ELF1.7A.Linking.20200731.pdf |A.pdf]]) * Loading ([[Media:ELF1.7B.Loading.20201103.pdf |B.pdf]]) * Executing ([[Media:ELF1.7C.Executing.20201221.pdf |C.pdf]]) * Virtual Memory ([[Media:ELF2.1D.VMemory.20211227.pdf |D.pdf]]) * PIC Method ([[Media:ELF1.7B.PICMethod.20200417.pdf |C.pdf]]) * Design Cycles ([[Media:ELF1.7C.DesignCycle.20200317.pdf |D.pdf]]) * Relocs in i386 ([[Media:ELF1.7D.Reloc386.20200413.pdf |E.pdf]]) ==== Relocation Examples ==== * Relocs example introduction ([[Media:ELF1.7Ex.1Intro.20200109.pdf |E1.pdf]]) * Relocs in an object for a library ([[Media:ELF1.7Ex.2ObjectRel.20200319.pdf |E2.pdf]]) * Relocs in an object for an executable ([[Media:ELF1.7Ex.3ObjectMain.20200118.pdf |E3.pdf]]) * Relocs in a library ([[Media:ELF1.7Ex.4Library.20200320.pdf |E4.pdf]]) * Relocs in an executable ([[Media:ELF1.7Ex.5Executable.20200228.pdf |E5.pdf]]) * Result Summary ([[Media:ELF1.7Ex.6Result.20200121.pdf |E6.pdf]]) * Symbol Table Listing ([[Media:ELF1.7Ex.7Symbol.20200120.pdf |E7.pdf]]) * Relocs Listing ([[Media:ELF1.7Ex.8Relocs.20200121.pdf |E8.pdf]]) * Assembly Listing ([[Media:ELF1.7Ex.9Assembly.20200128.pdf |E9.pdf]]) * Reloc Experiments ([[Media:ELF1.7F.Experiments.20191206.pdf |F.pdf]]) </br> go to [ [[C programming in plain view]] ] [[Category:C programming]] o4nr8dkfes4anmx32blc3aa7h6prhdg 2414072 2414070 2022-08-13T10:25:04Z Young1lim 21186 /* Object Files */ wikitext text/x-wiki === Executable and Linkable Format === ==== Object Files ==== * Introduction * ELF Header ([[Media:ELF1.1B.Header.20220211.pdf |pdf]]) * Group section ([[Media:ELF1.1C.Group.20220426.pdf |pdf]]) * String table section ([[Media:ELF1.1D.StringTbl.20220427.pdf |pdf]]) * Weak and common symbols ([[Media:ELF1.1E.WeakComm.20220811.pdf |pdf]]) * Symbol table section ([[Media:ELF1.1F.SymbolTbl.20220722.pdf |pdf]]) * Special Sections ([[Media:ELF1.7B.Section.20200511.pdf |B.pdf]]) * Relocation ([[Media:ELF1.6A.Relocation.20190413.pdf |A.pdf]]) ==== Program Loading and Dynamic Linking ==== * Introduction * Program Header ([[Media:ELF1.2B.ProgHeader.20220110.pdf |pdf]]) * Program Loading * Dynamic Linking ([[Media:ELF2.4A.DynLinking.20191028.pdf |pdf]]) ==== C Library ==== * C Library === ELF Study === ==== ELF Relocations ==== * Linking ([[Media:ELF1.7A.Linking.20200731.pdf |A.pdf]]) * Loading ([[Media:ELF1.7B.Loading.20201103.pdf |B.pdf]]) * Executing ([[Media:ELF1.7C.Executing.20201221.pdf |C.pdf]]) * Virtual Memory ([[Media:ELF2.1D.VMemory.20211227.pdf |D.pdf]]) * PIC Method ([[Media:ELF1.7B.PICMethod.20200417.pdf |C.pdf]]) * Design Cycles ([[Media:ELF1.7C.DesignCycle.20200317.pdf |D.pdf]]) * Relocs in i386 ([[Media:ELF1.7D.Reloc386.20200413.pdf |E.pdf]]) ==== Relocation Examples ==== * Relocs example introduction ([[Media:ELF1.7Ex.1Intro.20200109.pdf |E1.pdf]]) * Relocs in an object for a library ([[Media:ELF1.7Ex.2ObjectRel.20200319.pdf |E2.pdf]]) * Relocs in an object for an executable ([[Media:ELF1.7Ex.3ObjectMain.20200118.pdf |E3.pdf]]) * Relocs in a library ([[Media:ELF1.7Ex.4Library.20200320.pdf |E4.pdf]]) * Relocs in an executable ([[Media:ELF1.7Ex.5Executable.20200228.pdf |E5.pdf]]) * Result Summary ([[Media:ELF1.7Ex.6Result.20200121.pdf |E6.pdf]]) * Symbol Table Listing ([[Media:ELF1.7Ex.7Symbol.20200120.pdf |E7.pdf]]) * Relocs Listing ([[Media:ELF1.7Ex.8Relocs.20200121.pdf |E8.pdf]]) * Assembly Listing ([[Media:ELF1.7Ex.9Assembly.20200128.pdf |E9.pdf]]) * Reloc Experiments ([[Media:ELF1.7F.Experiments.20191206.pdf |F.pdf]]) </br> go to [ [[C programming in plain view]] ] [[Category:C programming]] dc0tdwy348ohj5ta4pywy64ek6muhmr 0 285677 2413952 2413809 2022-08-12T13:09:06Z ThaniosAkro 2805358 /* With 3 congruences */ wikitext text/x-wiki =Congruences= The subject of congruences is a field of mathematics that covers the integers, their relationship to each other and also the effect of arithmetic operations on their relationship to each other. Expressed mathematically: :<math>A \equiv B \pmod{N}</math> read as: A is congruent with B modulo N. {{RoundBoxTop|theme=2}} <math>A,B,N</math> are integers and <math>N > 1.</math> {{RoundBoxBottom}} This means that: * A modulo N equals B modulo N, * the difference, A-B, is exactly divisible by N, or * <math>A-B = K\cdot N.</math> where p modulo N or <code>p % N</code> is the remainder when p is divided by N. For example: <math>23 \equiv 8 \pmod{5}</math> because division <math>\frac{23-8}{5}</math> is exact without remainder, or <math>5\mid (23-8).</math> Similarly, <math>39 \not\equiv 29 \,\pmod{7}</math> because division <math>\frac{39-29}{7}</math> is not exact, or <math>7\nmid (39-29).</math> ==Law of addition== ===Adding a constant=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N}, </math> then: <math>A+q \equiv B+q \pmod{N}.</math> Proof: <math>A-B = K\cdot N</math>, therefore <math>A = B + K\cdot N.</math> <math>(A+q) - (B+q) = B + K\cdot N + q - B - q = K\cdot N</math> which is exactly divisible by N. {{RoundBoxBottom}} ===Adding 2 congruences=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N}, </math> and <math>C \equiv D \pmod{N}, </math> then: <math>A+C \equiv B+D \pmod{N}.</math> Proof: <math>A-B = K_1\cdot N</math>, therefore <math>A = B + K_1\cdot N</math> and <math>C = D + K_2\cdot N</math> <math>(A+C) - (B+D)</math> <math>= B + K_1\cdot N + D + K_2\cdot N - B - D</math> <math>= N(K_1 + K_2)</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of Common Congruence== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> and <math>C \equiv B \pmod{N},</math> then: <math>A \equiv C \pmod{N}.</math> Proof: <math>A = B + K_1\cdot N</math> and <math>C = B + K_2\cdot N.</math> <math>A - C = B + K_1\cdot N - B - K_2\cdot N = (K_1 - K_2)N</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of Multiplication== ===by a constant=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> then: <math>A\cdot p \equiv B\cdot p \pmod{N}.</math> Proof: <math>A\cdot p - B\cdot p = p(A-B)</math> which is exactly divisible by N. {{RoundBoxBottom}} ===by another congruence=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> and <math>C \equiv D \pmod{N},</math> then: <math>A\cdot C \equiv B\cdot D \pmod{N}.</math> Proof: <math>A = B + K_1\cdot N</math> and <math>C = D + K_2\cdot N.</math> <math>A\cdot C - B\cdot D</math> <math>= (B + K_1\cdot N)( D + K_2\cdot N) - B\cdot D</math> <math>= B\cdot D + B\cdot K_2\cdot N + K_1\cdot N\cdot D + K_1\cdot N\cdot K_2\cdot N - B\cdot D</math> <math>= N( B\cdot K_2 + K_1\cdot D + K_1\cdot K_2\cdot N )</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of squares== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> then: <math>A^2 \equiv B^2 \pmod{N}.</math> Proof: <math>A^2 - B^2 = (A+B)(A-B)</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of Division?== {{RoundBoxTop|theme=2}} A simple example shows that a "law of division" does not exist. <math>24 \equiv 14 \pmod{10}.</math> However <math>\frac{24}{2} \not\equiv \frac{14}{2} \pmod{10}</math> Because <math>12 - 7 = 5</math> is not exactly divisible by <math>10</math> {{RoundBoxBottom}} =Quadratic Congruences= A quadratic congruence is a congruence that contains at least one exact square, for example: <math>x^2 \equiv y \pmod{N}</math> or <math>x^2 \equiv y^2 \pmod{N}.</math> Initially, let us consider the congruence: <math>x^2 \equiv y \pmod{N}.</math> If <math>y = x^2 - N,</math> then: <math>x^2 \equiv y \pmod{N}.</math> Proof: <math>x^2 - y = x^2 - (x^2 - N) = N</math> which is exactly divisible by <math>N.</math> Consider an example with real numbers. Let <math>N = 257</math> and <math>26 \ge x \ge 6.</math> <syntaxhighlight> N = 257 </syntaxhighlight> {| class="wikitable" |- ! <math>x</math> !! <math>x^2 - N</math> |- | <code></code><code>6</code> || <code>-221</code> |- | <code></code><code>7</code> || <code>-208</code> |- | <code></code><code>8</code> || <code>-193</code> |- | <code></code><code>9</code> || <code>-176</code> |- | <code>10</code> || <code>-157</code> |- | <code>11</code> || <code>-136</code> |- | <code>12</code> || <code>-113</code> |- | <code>13</code> || <code></code><code>-88</code> |- | <code>14</code> || <code></code><code>-61</code> |- | <code>15</code> || <code></code><code>-32</code> |- | <code>16</code> || <code></code><code></code><code>-1</code> |- | <code>17</code> || <code></code><code></code><code>32</code> |- | <code>18</code> || <code></code><code></code><code>67</code> |- | <code>19</code> || <code></code><code>104</code> |- | <code>20</code> || <code></code><code>143</code> |- | <code>21</code> || <code></code><code>184</code> |- | <code>22</code> || <code></code><code>227</code> |- | <code>23</code> || <code></code><code>272</code> |- | <code>24</code> || <code></code><code>319</code> |- | <code>25</code> || <code></code><code>368</code> |- | <code>26</code> || <code></code><code>419</code> |} A cursory glance at the values of <math>x^2 - N</math> indicates that the value <math>x^2 - N</math> is never divisible by <math>5.</math> Proof: <math>N \equiv 2 \pmod{5}</math> therefore <math>N - 2 = k5</math> or <math>N = 5k + 2.</math> The table shows all possible values of <math>x\ %\ 5:</math> <syntaxhighlight> x | x^2 | y = x^2 - N ------ | --------------- | ----------------------------------------------- 5p + 0 | 25pp | 25pp - (5k+2) = 25pp - 5k - 2 5p + 1 | 25pp + 10p + 1 | 25pp + 10p + 1 - (5k+2) = 25pp + 10p - 5k - 1 5p + 2 | 25pp + 20p + 4 | 25pp + 20p + 4 - (5k+2) = 25pp + 20p - 5k + 2 5p + 3 | 25pp + 30p + 9 | 25pp + 30p + 9 - (5k+2) = 25pp + 30p - 5k + 7 5p + 4 | 25pp + 40p + 16 | 25pp + 40p + 16 - (5k+2) = 25pp + 40p - 5k + 14 </syntaxhighlight> As you can see, the value <math>y = x^2 - N</math> is never exactly divisible by <math>5.</math> If you look closely, you will see also that it is never exactly divisible by <math>3.</math> Why is this? An interesting question that leads us to the topic of quadratic residues. ==Quadratic Residues== Consider all the congruences for prime number <math>5:</math> <math>x^2 \equiv y \pmod{5}</math> for <math>5 > x \ge 0.</math> {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>(x^2)\ %\ 5</math> |- | <code>0</code> || <code></code><code>0</code> || <code>0</code> |- | <code>1</code> || <code></code><code>1</code> || <code>1</code> |- | <code>2</code> || <code></code><code>4</code> || <code>4</code> |- | <code>3</code> || <code></code><code>9</code> || <code>4</code> |- | <code>4</code> || <code>16</code> || <code>1</code> |} Quadratic residues of <math>5</math> are <math>0,1,4.</math> Values <math>2,3</math> are not quadratic residues of <math>5.</math> These values are quadratic non-residues. To calculate the quadratic residues of a small prime <math>p:</math> <syntaxhighlight lang=python> # python code: def quadResidues(p) : L1 = [] for v in range (p>>1, -1, -1) : L1 += [(v*v) % p] return L1 print (quadResidues(11)) </syntaxhighlight> <syntaxhighlight> [3, 5, 9, 4, 1, 0] </syntaxhighlight> Quadratic residues of <math>11</math> are <math>0,1,3,4,5,9.</math> The method presented here answers the question, "What are the quadratic residues of p?" If <math>p</math> is a very large prime, the question is often, "Is r a quadratic residue of p?" The answer is found in advanced number theory. Let us return to quadratic residues mod <math>N = 257.</math> <math>N\ %\ 5 = 2,</math> therefore <math>N</math> is not a quadratic residue of <math>5.</math> This is why <math>x^2 - N</math> is never divisible by <math>5</math> exactly. <math>N\ %\ 11 = 4,</math> therefore <math>N</math> is a quadratic residue of <math>11</math> and a value of <math>x</math> that satisfies the congruence <math>x^2 \equiv 4 \pmod{257}</math> has form <math>11p \pm 2.</math> From the table above: <syntaxhighlight> N = 257 </syntaxhighlight> {| class="wikitable" |- ! <math>x</math> !! <math>x^2\ -\ N</math> |- | <code></code><code>9</code> || <code>-176</code> |- | <code>13</code> || <code></code><code>-88</code> |- | <code>20</code> || <code></code><code>143</code> |- | <code>24</code> || <code></code><code>319</code> |} These <math>4</math> values of <math>x^2 - N</math> are exactly divisible by <math>11.</math> <math>x = 9</math> is <math>11\cdot 1 - 2.</math> <math>x = 13</math> is <math>11\cdot 1 + 2.</math> <math>x = 20</math> is <math>11\cdot 2 - 2.</math> <math>x = 24</math> is <math>11\cdot 2 + 2.</math> ===Products=== This section uses prime number <math>41</math> as an example. Using <code>quadResidues(p)</code> quadratic residues of <math>41</math> are: <syntaxhighlight> qr41 = [0, 1, 2, 4, 5, 8, 9, 10, 16, 18, 20, 21, 23, 25, 31, 32, 33, 36, 37, 39, 40] </syntaxhighlight> Quadratic non-residues of <math>41</math> are: <syntaxhighlight> qnr41 = [3, 6, 7, 11, 12, 13, 14, 15, 17, 19, 22, 24, 26, 27, 28, 29, 30, 34, 35, 38] </syntaxhighlight> ====of 2 residues==== A simple test to verify that the product of 2 residues is a residue: <syntaxhighlight lang=python> # Python code. for index1 in range (0, len(qr41)) : v1 = qr41[index1] for index2 in range (index1, len(qr41)) : v2 = qr41[index2] residue = (v1*v2) % 41 if residue not in qr41 : print ('residue',residue,'not quadratic.') </syntaxhighlight> This test shows that, at least for prime number <math>41,</math> the product of 2 residues is a residue. Advanced math proves that this is true for all primes. ====of 2 non-residues==== A simple test to verify that the product of 2 non-residues is a residue: <syntaxhighlight lang=python> # Python code. for index1 in range (0, len(qnr41)) : v1 = qnr41[index1] for index2 in range (index1, len(qnr41)) : v2 = qnr41[index2] residue = (v1*v2) % 41 if residue not in qr41 : print ('residue',residue,'not quadratic.') </syntaxhighlight> This test shows that, at least for prime number <math>41,</math> the product of 2 non-residues is a residue. Advanced math proves that this is true for all primes. ====of residue and non-residue==== A simple test to verify that the product of residue and non-residue is non-residue: <syntaxhighlight lang=python> # Python code. for index1 in range (1, len(qr41)) : v1 = qr41[index1] for index2 in range (0, len(qnr41)) : v2 = qnr41[index2] residue = (v1*v2) % 41 if residue not in qnr41 : print ('residue',residue,'quadratic.') </syntaxhighlight> This test shows that, at least for prime number <math>41,</math> the product of residue and non-residue is non-residue. Advanced math proves that this is true for all primes. {{RoundBoxTop|theme=2}} Some authors may consider <math>0</math> as not a legitimate residue. <math>0</math> is not included as a residue in the test above. {{RoundBoxBottom}} ==Euler's criterion== In number theory, '''Euler's criterion''' is a formula for determining whether or not an integer is a quadratic residue modulo a prime number. Precisely, Let ''p'' be an odd prime and ''a'' be an integer coprime to ''p''. Then :<math> a^{\tfrac{p-1}{2}} \equiv \begin{cases} \;\;\,1\pmod{p}& \text{ if there is an integer }x \text{ such that }a\equiv x^2 \pmod{p},\\ -1\pmod{p}& \text{ if there is no such integer.} \end{cases} </math> Euler's criterion can be concisely reformulated using the Legendre symbol: :<math> \left(\frac{a}{p}\right) \equiv a^{\tfrac{p-1}{2}} \pmod p. </math> :<math>\left(\frac{a}{p}\right) = \begin{cases} 1 & \text{if } a \text{ is a quadratic residue modulo } p \text{ and } a \not\equiv 0\pmod p, \\ -1 & \text{if } a \text{ is a non-quadratic residue modulo } p, \\ 0 & \text{if } a \equiv 0 \pmod p. \end{cases}</math> It is known that <math>3</math> is a quadratic residue modulo <math>11.</math> Therefore <math>(3^5)\ %\ 11</math> should be <math>1.</math> <syntaxhighlight lang=python> # python code: >>> (3**5) % 11 1 </syntaxhighlight> It is known that <math>7</math> is a quadratic non-residue modulo <math>11.</math> Therefore <math>(7^5)\ %\ 11</math> should be <math>-1.</math> <syntaxhighlight lang=python> # python code: >>> (7**5) % 11 10 </syntaxhighlight> :<math>10 \equiv -1 \pmod{11}</math> Python's decimal module provides a method for computing <math>(a^x)\ %\ p</math> very efficiently for both small and very large numbers. <syntaxhighlight lang=python> # python code: >>> import decimal >>> decimal.Context().power(3,5,11) Decimal('1') >>> decimal.Context().power(7,5,11) Decimal('10') >>> >>> a = 3456789 >>> p = 761838257287 >>> decimal.Context().power(a, p>>1, p) Decimal('761838257286') </syntaxhighlight> :<math>761838257286 \equiv -1 \pmod{761838257287}</math> Value <math>a = 3456789</math> is not a quadratic residue modulo <math>p = 761838257287.</math> {{RoundBoxTop|theme=3}} An exact square such as <math>1,4,9,16,25,\dots</math> is always a quadratic residue modulo an odd prime <math>p.</math> {{RoundBoxBottom}} ===Product of 2 residues=== Let <math>a,b</math> be quadratic residues modulo odd prime <math>p.</math> Let <math>q = \frac{p-1}{2}.</math> Then: <math>a^q \equiv 1 \pmod p</math> <math>b^q \equiv 1 \pmod p</math> By law of multiplication: <math>(a^q)(b^q) \equiv (1)(1) \pmod p</math> or <math>(a\cdot b)^q \equiv 1 \pmod p</math> Product <math>(a\cdot b)</math> of 2 quadratic residues <math>a, b</math> is quadratic residue. Similarly, product of 2 non-residues is residue, and product of residue and non-residue is non-residue. ==Factors of integer N== Several modern methods for determining the factors of a given integer attempt to create two congruent squares modulo integer <math>N.</math> <math>x^2 \equiv y^2 \pmod{N}</math> This means that the difference between the two squares is exactly divisible by <math>N</math>: <math>N\mid (x^2 - y^2).</math> Integer <math>N</math> always contains the factors <math>N,1,</math> called trivial factors. If <math>N</math> contains two non-trivial factors <math>p,q,</math> then: <math>\frac{(x+y)(x-y)}{p \cdot q}.</math> With a little luck <math>p\mid (x+y)</math> and <math>q\mid (x-y)</math> in which case: <math>p = \text{igcd}(x+y, N)</math> and <math>q = \text{igcd}(x-y, N)</math> where "<math>\text{igcd}</math>" is function "<math>\text{integer greatest common divisor.}</math>" ===A simple example:=== We will use quadratic congruences to calculate factors of <math>N = 4171</math> for <math>164 \ge x \ge 1.</math> ====Right hand side exact square==== One congruence produced an exact square for y: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 70 | 4900 | 729 |} :<math>4900 \equiv 729 \pmod{N}</math> :<math>70^2 \equiv 27^2 \pmod{N}</math> <math>p = \text{igcd}(70-27, 4171)</math> <math>= \text{igcd}(43, 4171)</math> <math>= 43.</math> <math>q = \text{igcd}(70+27, 4171)</math> <math>= \text{igcd}(97, 4171)</math> <math>= 97.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> ====Right hand side negative==== Table below contains a sample of values of <math>x</math> that produce negative <math>y:</math> {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 7 | 49 | -4122 |- | 8 | 64 | -4107 ** |- | 9 | 81 | -4090 |- | 10 | 100 | -4071 |- | 11 | 121 | -4050 !! |- | 12 | 144 | -4027 |- | 60 | 3600 | -571 |- | 61 | 3721 | -450 <math>\ \ </math>!! |- | 62 | 3844 | -327 |- | 63 | 3969 | -202 |- | 64 | 4096 | -75 <math>\ \ \ \ </math>** |} =====Non-trivial result 1===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 8 | 64 | -4107 ** |- | 64 | 4096 | -75 <math>\ \ \ \ </math>** |} :<math>64 \equiv -4107 \pmod{N}</math> :<math>4096 \equiv -75 \pmod{N}</math> :<math>64\cdot 4096 \equiv -4107\cdot (-75) \pmod{N}</math> :<math>262144 \equiv 308025 \pmod{N}</math> :<math>512^2 \equiv 555^2 \pmod{4171}</math> <math>p = \text{igcd}(555-512, 4171)</math> <math>= \text{igcd}(43, 4171)</math> <math>= 43.</math> <math>q = \text{igcd}(555+512, 4171)</math> <math>= \text{igcd}(1067, 4171)</math> <math>= 97.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> =====Non-trivial result 2===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <code>11</code> || <code></code><code>121</code> || <code>-4050</code><code>!!</code> |- | <code>61</code> || <code>3721</code> || <code></code><code>-450</code><code>!!</code> |} :<math>121 \equiv -4050 \pmod{N}</math> :<math>3721 \equiv -450 \pmod{N}</math> :<math>121\cdot 3721 \equiv -4050 \cdot (-450) \pmod{N}</math> :<math>450241 \equiv 1822500 \pmod{N}</math> :<math>671^2 \equiv 1350^2 \pmod{4171}</math> <math>p = \text{igcd}(1350-671, 4171)</math> <math>= \text{igcd}(679, 4171)</math> <math>= 97.</math> <math>q = \text{igcd}(1350+671, 4171)</math> <math>= \text{igcd}(2021, 4171)</math> <math>= 43.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> ====Right hand side positive==== Table below contains a sample of values of <math>x</math> that produce positive <math>y:</math> {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 65 | 4225 | 54 <math>\ \ \ </math>** |- | 66 | 4356 | 185 |- | 88 | 7744 | 3573 |- | 89 | 7921 | 3750 **!! |- | 90 | 8100 | 3929 |- | 144 | 20736 | 16565 |- | 145 | 21025 | 16854 <math>\ </math>!! |- | 146 | 21316 | 17145 |} =====Non-trivial result===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 65 | 4225 | 54 <math>\ \ \ </math>** |- | 89 | 7921 | 3750 **!! |} :<math>4225 \equiv 54 \pmod{N}</math> :<math>7921 \equiv 3750 \pmod{N}</math> :<math>4225\cdot 7921 \equiv 54 \cdot 3750 \pmod{N}</math> :<math>33466225 \equiv 202500 \pmod{N}</math> :<math>5785^2 \equiv 450^2 \pmod{4171}</math> <math>p = \text{igcd}(5785-450, 4171)</math> <math>= \text{igcd}(5335, 4171)</math> <math>= 97.</math> <math>q = \text{igcd}(5785+450, 4171)</math> <math>= \text{igcd}(6235, 4171)</math> <math>= 43.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> =====Trivial result===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 89 | 7921 | 3750 **!! |- | 145 | 21025 | 16854 <math>\ </math>!! |} :<math>7921 \equiv 3750 \pmod{N}</math> :<math>21025 \equiv 16854 \pmod{N}</math> :<math>7921\cdot 21025 \equiv 3750 \cdot 16854 \pmod{N}</math> :<math>166539025 \equiv 63202500 \pmod{N}</math> :<math>12905^2 \equiv 7950^2 \pmod{4171}</math> <math>p = \text{igcd}(12905-7950, 4171)</math> <math>= \text{igcd}(4955, 4171)</math> <math>= 1.</math> <math>q = \text{igcd}(12905+7950, 4171)</math> <math>= \text{igcd}(20855, 4171)</math> <math>= 4171.</math> This congruence produced the trivial factors of <math>4171.</math> ====With 3 congruences==== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <math>\ \ </math><code>56</code>||<math>\ \ </math><code>3136</code>||<code>-1035</code> |- | <math>\ \ </math><code>59</code>||<math>\ \ </math><code>3481</code>||<math>\ \ </math><code>-690</code> |- | <code>145</code>||<code>21025</code>||<code>16854</code> |} :<math>3136 \equiv -1035 \pmod{N}</math> :<math>3481 \equiv -690 \pmod{N}</math> :<math>21025 \equiv 16854 \pmod{N}</math> :<math>3136\cdot 3481 \cdot 21025 \equiv -1035 \cdot -690 \cdot 16854 \pmod{N}</math> :<math>229517646400 \equiv 12036284100 \pmod{N}</math> :<math>479080^2 \equiv 109710^2 \pmod{4171}</math> <math>p=\text{igcd}(479080-109710,4171)</math> <math>= 43.</math> <math>q = \text{igcd}(479080+109710, 4171)</math> <math>= 97.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> =Links to related topics= [https://en.wikipedia.org/wiki/Quadratic_residue Quadratic Residue] [https://en.wikipedia.org/wiki/Modular_arithmetic Modular Arithmetic] [https://en.wikipedia.org/wiki/Leonhard_Euler Leonhard Euler,] [https://en.wikipedia.org/wiki/Euler%27s_criterion Euler's Criterion] [https://en.wikipedia.org/wiki/Adrien-Marie_Legendre Adrien-Marie Legendre,] [https://en.wikipedia.org/wiki/Legendre_symbol Legendre Symbol] [https://en.wikipedia.org/wiki/Carl_Pomerance Carl Pomerance,] [https://en.wikipedia.org/wiki/Quadratic_sieve Quadratic sieve] [https://en.wikipedia.org/wiki/Greatest_common_divisor Greatest common divisor,] [https://en.wikipedia.org/wiki/Recursion_(computer_science)#Greatest_common_divisor Greatest common divisor (Example of Recursion)] [https://docs.python.org/3.4/library/decimal.html?highlight=decimal#decimal.Context.power Python's decimal Module] 2zywj6bn8eyqxcoi0yq57pl37zvo5q2 2413953 2413952 2022-08-12T13:14:01Z ThaniosAkro 2805358 /* Trivial result */ wikitext text/x-wiki =Congruences= The subject of congruences is a field of mathematics that covers the integers, their relationship to each other and also the effect of arithmetic operations on their relationship to each other. Expressed mathematically: :<math>A \equiv B \pmod{N}</math> read as: A is congruent with B modulo N. {{RoundBoxTop|theme=2}} <math>A,B,N</math> are integers and <math>N > 1.</math> {{RoundBoxBottom}} This means that: * A modulo N equals B modulo N, * the difference, A-B, is exactly divisible by N, or * <math>A-B = K\cdot N.</math> where p modulo N or <code>p % N</code> is the remainder when p is divided by N. For example: <math>23 \equiv 8 \pmod{5}</math> because division <math>\frac{23-8}{5}</math> is exact without remainder, or <math>5\mid (23-8).</math> Similarly, <math>39 \not\equiv 29 \,\pmod{7}</math> because division <math>\frac{39-29}{7}</math> is not exact, or <math>7\nmid (39-29).</math> ==Law of addition== ===Adding a constant=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N}, </math> then: <math>A+q \equiv B+q \pmod{N}.</math> Proof: <math>A-B = K\cdot N</math>, therefore <math>A = B + K\cdot N.</math> <math>(A+q) - (B+q) = B + K\cdot N + q - B - q = K\cdot N</math> which is exactly divisible by N. {{RoundBoxBottom}} ===Adding 2 congruences=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N}, </math> and <math>C \equiv D \pmod{N}, </math> then: <math>A+C \equiv B+D \pmod{N}.</math> Proof: <math>A-B = K_1\cdot N</math>, therefore <math>A = B + K_1\cdot N</math> and <math>C = D + K_2\cdot N</math> <math>(A+C) - (B+D)</math> <math>= B + K_1\cdot N + D + K_2\cdot N - B - D</math> <math>= N(K_1 + K_2)</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of Common Congruence== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> and <math>C \equiv B \pmod{N},</math> then: <math>A \equiv C \pmod{N}.</math> Proof: <math>A = B + K_1\cdot N</math> and <math>C = B + K_2\cdot N.</math> <math>A - C = B + K_1\cdot N - B - K_2\cdot N = (K_1 - K_2)N</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of Multiplication== ===by a constant=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> then: <math>A\cdot p \equiv B\cdot p \pmod{N}.</math> Proof: <math>A\cdot p - B\cdot p = p(A-B)</math> which is exactly divisible by N. {{RoundBoxBottom}} ===by another congruence=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> and <math>C \equiv D \pmod{N},</math> then: <math>A\cdot C \equiv B\cdot D \pmod{N}.</math> Proof: <math>A = B + K_1\cdot N</math> and <math>C = D + K_2\cdot N.</math> <math>A\cdot C - B\cdot D</math> <math>= (B + K_1\cdot N)( D + K_2\cdot N) - B\cdot D</math> <math>= B\cdot D + B\cdot K_2\cdot N + K_1\cdot N\cdot D + K_1\cdot N\cdot K_2\cdot N - B\cdot D</math> <math>= N( B\cdot K_2 + K_1\cdot D + K_1\cdot K_2\cdot N )</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of squares== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> then: <math>A^2 \equiv B^2 \pmod{N}.</math> Proof: <math>A^2 - B^2 = (A+B)(A-B)</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of Division?== {{RoundBoxTop|theme=2}} A simple example shows that a "law of division" does not exist. <math>24 \equiv 14 \pmod{10}.</math> However <math>\frac{24}{2} \not\equiv \frac{14}{2} \pmod{10}</math> Because <math>12 - 7 = 5</math> is not exactly divisible by <math>10</math> {{RoundBoxBottom}} =Quadratic Congruences= A quadratic congruence is a congruence that contains at least one exact square, for example: <math>x^2 \equiv y \pmod{N}</math> or <math>x^2 \equiv y^2 \pmod{N}.</math> Initially, let us consider the congruence: <math>x^2 \equiv y \pmod{N}.</math> If <math>y = x^2 - N,</math> then: <math>x^2 \equiv y \pmod{N}.</math> Proof: <math>x^2 - y = x^2 - (x^2 - N) = N</math> which is exactly divisible by <math>N.</math> Consider an example with real numbers. Let <math>N = 257</math> and <math>26 \ge x \ge 6.</math> <syntaxhighlight> N = 257 </syntaxhighlight> {| class="wikitable" |- ! <math>x</math> !! <math>x^2 - N</math> |- | <code></code><code>6</code> || <code>-221</code> |- | <code></code><code>7</code> || <code>-208</code> |- | <code></code><code>8</code> || <code>-193</code> |- | <code></code><code>9</code> || <code>-176</code> |- | <code>10</code> || <code>-157</code> |- | <code>11</code> || <code>-136</code> |- | <code>12</code> || <code>-113</code> |- | <code>13</code> || <code></code><code>-88</code> |- | <code>14</code> || <code></code><code>-61</code> |- | <code>15</code> || <code></code><code>-32</code> |- | <code>16</code> || <code></code><code></code><code>-1</code> |- | <code>17</code> || <code></code><code></code><code>32</code> |- | <code>18</code> || <code></code><code></code><code>67</code> |- | <code>19</code> || <code></code><code>104</code> |- | <code>20</code> || <code></code><code>143</code> |- | <code>21</code> || <code></code><code>184</code> |- | <code>22</code> || <code></code><code>227</code> |- | <code>23</code> || <code></code><code>272</code> |- | <code>24</code> || <code></code><code>319</code> |- | <code>25</code> || <code></code><code>368</code> |- | <code>26</code> || <code></code><code>419</code> |} A cursory glance at the values of <math>x^2 - N</math> indicates that the value <math>x^2 - N</math> is never divisible by <math>5.</math> Proof: <math>N \equiv 2 \pmod{5}</math> therefore <math>N - 2 = k5</math> or <math>N = 5k + 2.</math> The table shows all possible values of <math>x\ %\ 5:</math> <syntaxhighlight> x | x^2 | y = x^2 - N ------ | --------------- | ----------------------------------------------- 5p + 0 | 25pp | 25pp - (5k+2) = 25pp - 5k - 2 5p + 1 | 25pp + 10p + 1 | 25pp + 10p + 1 - (5k+2) = 25pp + 10p - 5k - 1 5p + 2 | 25pp + 20p + 4 | 25pp + 20p + 4 - (5k+2) = 25pp + 20p - 5k + 2 5p + 3 | 25pp + 30p + 9 | 25pp + 30p + 9 - (5k+2) = 25pp + 30p - 5k + 7 5p + 4 | 25pp + 40p + 16 | 25pp + 40p + 16 - (5k+2) = 25pp + 40p - 5k + 14 </syntaxhighlight> As you can see, the value <math>y = x^2 - N</math> is never exactly divisible by <math>5.</math> If you look closely, you will see also that it is never exactly divisible by <math>3.</math> Why is this? An interesting question that leads us to the topic of quadratic residues. ==Quadratic Residues== Consider all the congruences for prime number <math>5:</math> <math>x^2 \equiv y \pmod{5}</math> for <math>5 > x \ge 0.</math> {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>(x^2)\ %\ 5</math> |- | <code>0</code> || <code></code><code>0</code> || <code>0</code> |- | <code>1</code> || <code></code><code>1</code> || <code>1</code> |- | <code>2</code> || <code></code><code>4</code> || <code>4</code> |- | <code>3</code> || <code></code><code>9</code> || <code>4</code> |- | <code>4</code> || <code>16</code> || <code>1</code> |} Quadratic residues of <math>5</math> are <math>0,1,4.</math> Values <math>2,3</math> are not quadratic residues of <math>5.</math> These values are quadratic non-residues. To calculate the quadratic residues of a small prime <math>p:</math> <syntaxhighlight lang=python> # python code: def quadResidues(p) : L1 = [] for v in range (p>>1, -1, -1) : L1 += [(v*v) % p] return L1 print (quadResidues(11)) </syntaxhighlight> <syntaxhighlight> [3, 5, 9, 4, 1, 0] </syntaxhighlight> Quadratic residues of <math>11</math> are <math>0,1,3,4,5,9.</math> The method presented here answers the question, "What are the quadratic residues of p?" If <math>p</math> is a very large prime, the question is often, "Is r a quadratic residue of p?" The answer is found in advanced number theory. Let us return to quadratic residues mod <math>N = 257.</math> <math>N\ %\ 5 = 2,</math> therefore <math>N</math> is not a quadratic residue of <math>5.</math> This is why <math>x^2 - N</math> is never divisible by <math>5</math> exactly. <math>N\ %\ 11 = 4,</math> therefore <math>N</math> is a quadratic residue of <math>11</math> and a value of <math>x</math> that satisfies the congruence <math>x^2 \equiv 4 \pmod{257}</math> has form <math>11p \pm 2.</math> From the table above: <syntaxhighlight> N = 257 </syntaxhighlight> {| class="wikitable" |- ! <math>x</math> !! <math>x^2\ -\ N</math> |- | <code></code><code>9</code> || <code>-176</code> |- | <code>13</code> || <code></code><code>-88</code> |- | <code>20</code> || <code></code><code>143</code> |- | <code>24</code> || <code></code><code>319</code> |} These <math>4</math> values of <math>x^2 - N</math> are exactly divisible by <math>11.</math> <math>x = 9</math> is <math>11\cdot 1 - 2.</math> <math>x = 13</math> is <math>11\cdot 1 + 2.</math> <math>x = 20</math> is <math>11\cdot 2 - 2.</math> <math>x = 24</math> is <math>11\cdot 2 + 2.</math> ===Products=== This section uses prime number <math>41</math> as an example. Using <code>quadResidues(p)</code> quadratic residues of <math>41</math> are: <syntaxhighlight> qr41 = [0, 1, 2, 4, 5, 8, 9, 10, 16, 18, 20, 21, 23, 25, 31, 32, 33, 36, 37, 39, 40] </syntaxhighlight> Quadratic non-residues of <math>41</math> are: <syntaxhighlight> qnr41 = [3, 6, 7, 11, 12, 13, 14, 15, 17, 19, 22, 24, 26, 27, 28, 29, 30, 34, 35, 38] </syntaxhighlight> ====of 2 residues==== A simple test to verify that the product of 2 residues is a residue: <syntaxhighlight lang=python> # Python code. for index1 in range (0, len(qr41)) : v1 = qr41[index1] for index2 in range (index1, len(qr41)) : v2 = qr41[index2] residue = (v1*v2) % 41 if residue not in qr41 : print ('residue',residue,'not quadratic.') </syntaxhighlight> This test shows that, at least for prime number <math>41,</math> the product of 2 residues is a residue. Advanced math proves that this is true for all primes. ====of 2 non-residues==== A simple test to verify that the product of 2 non-residues is a residue: <syntaxhighlight lang=python> # Python code. for index1 in range (0, len(qnr41)) : v1 = qnr41[index1] for index2 in range (index1, len(qnr41)) : v2 = qnr41[index2] residue = (v1*v2) % 41 if residue not in qr41 : print ('residue',residue,'not quadratic.') </syntaxhighlight> This test shows that, at least for prime number <math>41,</math> the product of 2 non-residues is a residue. Advanced math proves that this is true for all primes. ====of residue and non-residue==== A simple test to verify that the product of residue and non-residue is non-residue: <syntaxhighlight lang=python> # Python code. for index1 in range (1, len(qr41)) : v1 = qr41[index1] for index2 in range (0, len(qnr41)) : v2 = qnr41[index2] residue = (v1*v2) % 41 if residue not in qnr41 : print ('residue',residue,'quadratic.') </syntaxhighlight> This test shows that, at least for prime number <math>41,</math> the product of residue and non-residue is non-residue. Advanced math proves that this is true for all primes. {{RoundBoxTop|theme=2}} Some authors may consider <math>0</math> as not a legitimate residue. <math>0</math> is not included as a residue in the test above. {{RoundBoxBottom}} ==Euler's criterion== In number theory, '''Euler's criterion''' is a formula for determining whether or not an integer is a quadratic residue modulo a prime number. Precisely, Let ''p'' be an odd prime and ''a'' be an integer coprime to ''p''. Then :<math> a^{\tfrac{p-1}{2}} \equiv \begin{cases} \;\;\,1\pmod{p}& \text{ if there is an integer }x \text{ such that }a\equiv x^2 \pmod{p},\\ -1\pmod{p}& \text{ if there is no such integer.} \end{cases} </math> Euler's criterion can be concisely reformulated using the Legendre symbol: :<math> \left(\frac{a}{p}\right) \equiv a^{\tfrac{p-1}{2}} \pmod p. </math> :<math>\left(\frac{a}{p}\right) = \begin{cases} 1 & \text{if } a \text{ is a quadratic residue modulo } p \text{ and } a \not\equiv 0\pmod p, \\ -1 & \text{if } a \text{ is a non-quadratic residue modulo } p, \\ 0 & \text{if } a \equiv 0 \pmod p. \end{cases}</math> It is known that <math>3</math> is a quadratic residue modulo <math>11.</math> Therefore <math>(3^5)\ %\ 11</math> should be <math>1.</math> <syntaxhighlight lang=python> # python code: >>> (3**5) % 11 1 </syntaxhighlight> It is known that <math>7</math> is a quadratic non-residue modulo <math>11.</math> Therefore <math>(7^5)\ %\ 11</math> should be <math>-1.</math> <syntaxhighlight lang=python> # python code: >>> (7**5) % 11 10 </syntaxhighlight> :<math>10 \equiv -1 \pmod{11}</math> Python's decimal module provides a method for computing <math>(a^x)\ %\ p</math> very efficiently for both small and very large numbers. <syntaxhighlight lang=python> # python code: >>> import decimal >>> decimal.Context().power(3,5,11) Decimal('1') >>> decimal.Context().power(7,5,11) Decimal('10') >>> >>> a = 3456789 >>> p = 761838257287 >>> decimal.Context().power(a, p>>1, p) Decimal('761838257286') </syntaxhighlight> :<math>761838257286 \equiv -1 \pmod{761838257287}</math> Value <math>a = 3456789</math> is not a quadratic residue modulo <math>p = 761838257287.</math> {{RoundBoxTop|theme=3}} An exact square such as <math>1,4,9,16,25,\dots</math> is always a quadratic residue modulo an odd prime <math>p.</math> {{RoundBoxBottom}} ===Product of 2 residues=== Let <math>a,b</math> be quadratic residues modulo odd prime <math>p.</math> Let <math>q = \frac{p-1}{2}.</math> Then: <math>a^q \equiv 1 \pmod p</math> <math>b^q \equiv 1 \pmod p</math> By law of multiplication: <math>(a^q)(b^q) \equiv (1)(1) \pmod p</math> or <math>(a\cdot b)^q \equiv 1 \pmod p</math> Product <math>(a\cdot b)</math> of 2 quadratic residues <math>a, b</math> is quadratic residue. Similarly, product of 2 non-residues is residue, and product of residue and non-residue is non-residue. ==Factors of integer N== Several modern methods for determining the factors of a given integer attempt to create two congruent squares modulo integer <math>N.</math> <math>x^2 \equiv y^2 \pmod{N}</math> This means that the difference between the two squares is exactly divisible by <math>N</math>: <math>N\mid (x^2 - y^2).</math> Integer <math>N</math> always contains the factors <math>N,1,</math> called trivial factors. If <math>N</math> contains two non-trivial factors <math>p,q,</math> then: <math>\frac{(x+y)(x-y)}{p \cdot q}.</math> With a little luck <math>p\mid (x+y)</math> and <math>q\mid (x-y)</math> in which case: <math>p = \text{igcd}(x+y, N)</math> and <math>q = \text{igcd}(x-y, N)</math> where "<math>\text{igcd}</math>" is function "<math>\text{integer greatest common divisor.}</math>" ===A simple example:=== We will use quadratic congruences to calculate factors of <math>N = 4171</math> for <math>164 \ge x \ge 1.</math> ====Right hand side exact square==== One congruence produced an exact square for y: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 70 | 4900 | 729 |} :<math>4900 \equiv 729 \pmod{N}</math> :<math>70^2 \equiv 27^2 \pmod{N}</math> <math>p = \text{igcd}(70-27, 4171)</math> <math>= \text{igcd}(43, 4171)</math> <math>= 43.</math> <math>q = \text{igcd}(70+27, 4171)</math> <math>= \text{igcd}(97, 4171)</math> <math>= 97.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> ====Right hand side negative==== Table below contains a sample of values of <math>x</math> that produce negative <math>y:</math> {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 7 | 49 | -4122 |- | 8 | 64 | -4107 ** |- | 9 | 81 | -4090 |- | 10 | 100 | -4071 |- | 11 | 121 | -4050 !! |- | 12 | 144 | -4027 |- | 60 | 3600 | -571 |- | 61 | 3721 | -450 <math>\ \ </math>!! |- | 62 | 3844 | -327 |- | 63 | 3969 | -202 |- | 64 | 4096 | -75 <math>\ \ \ \ </math>** |} =====Non-trivial result 1===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 8 | 64 | -4107 ** |- | 64 | 4096 | -75 <math>\ \ \ \ </math>** |} :<math>64 \equiv -4107 \pmod{N}</math> :<math>4096 \equiv -75 \pmod{N}</math> :<math>64\cdot 4096 \equiv -4107\cdot (-75) \pmod{N}</math> :<math>262144 \equiv 308025 \pmod{N}</math> :<math>512^2 \equiv 555^2 \pmod{4171}</math> <math>p = \text{igcd}(555-512, 4171)</math> <math>= \text{igcd}(43, 4171)</math> <math>= 43.</math> <math>q = \text{igcd}(555+512, 4171)</math> <math>= \text{igcd}(1067, 4171)</math> <math>= 97.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> =====Non-trivial result 2===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <code>11</code> || <code></code><code>121</code> || <code>-4050</code><code>!!</code> |- | <code>61</code> || <code>3721</code> || <code></code><code>-450</code><code>!!</code> |} :<math>121 \equiv -4050 \pmod{N}</math> :<math>3721 \equiv -450 \pmod{N}</math> :<math>121\cdot 3721 \equiv -4050 \cdot (-450) \pmod{N}</math> :<math>450241 \equiv 1822500 \pmod{N}</math> :<math>671^2 \equiv 1350^2 \pmod{4171}</math> <math>p = \text{igcd}(1350-671, 4171)</math> <math>= \text{igcd}(679, 4171)</math> <math>= 97.</math> <math>q = \text{igcd}(1350+671, 4171)</math> <math>= \text{igcd}(2021, 4171)</math> <math>= 43.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> ====Right hand side positive==== Table below contains a sample of values of <math>x</math> that produce positive <math>y:</math> {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 65 | 4225 | 54 <math>\ \ \ </math>** |- | 66 | 4356 | 185 |- | 88 | 7744 | 3573 |- | 89 | 7921 | 3750 **!! |- | 90 | 8100 | 3929 |- | 144 | 20736 | 16565 |- | 145 | 21025 | 16854 <math>\ </math>!! |- | 146 | 21316 | 17145 |} =====Non-trivial result===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 65 | 4225 | 54 <math>\ \ \ </math>** |- | 89 | 7921 | 3750 **!! |} :<math>4225 \equiv 54 \pmod{N}</math> :<math>7921 \equiv 3750 \pmod{N}</math> :<math>4225\cdot 7921 \equiv 54 \cdot 3750 \pmod{N}</math> :<math>33466225 \equiv 202500 \pmod{N}</math> :<math>5785^2 \equiv 450^2 \pmod{4171}</math> <math>p = \text{igcd}(5785-450, 4171)</math> <math>= \text{igcd}(5335, 4171)</math> <math>= 97.</math> <math>q = \text{igcd}(5785+450, 4171)</math> <math>= \text{igcd}(6235, 4171)</math> <math>= 43.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> =====Trivial result===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <math>\ \ </math><code>89</code>||<math>\ \ </math><code>7921</code>||<math>\ \ </math><code>3750</code><math>\ \ </math><code>**!!</code> |- | <code>145</code>||<code>21025</code>||<code>16854</code><math>\ \ \ \ \ \ </math><code>!!</code> |} :<math>7921 \equiv 3750 \pmod{N}</math> :<math>21025 \equiv 16854 \pmod{N}</math> :<math>7921\cdot 21025 \equiv 3750 \cdot 16854 \pmod{N}</math> :<math>166539025 \equiv 63202500 \pmod{N}</math> :<math>12905^2 \equiv 7950^2 \pmod{4171}</math> <math>p = \text{igcd}(12905-7950, 4171)</math> <math>= \text{igcd}(4955, 4171)</math> <math>= 1.</math> <math>q = \text{igcd}(12905+7950, 4171)</math> <math>= \text{igcd}(20855, 4171)</math> <math>= 4171.</math> This congruence produced the trivial factors of <math>4171.</math> ====With 3 congruences==== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <math>\ \ </math><code>56</code>||<math>\ \ </math><code>3136</code>||<code>-1035</code> |- | <math>\ \ </math><code>59</code>||<math>\ \ </math><code>3481</code>||<math>\ \ </math><code>-690</code> |- | <code>145</code>||<code>21025</code>||<code>16854</code> |} :<math>3136 \equiv -1035 \pmod{N}</math> :<math>3481 \equiv -690 \pmod{N}</math> :<math>21025 \equiv 16854 \pmod{N}</math> :<math>3136\cdot 3481 \cdot 21025 \equiv -1035 \cdot -690 \cdot 16854 \pmod{N}</math> :<math>229517646400 \equiv 12036284100 \pmod{N}</math> :<math>479080^2 \equiv 109710^2 \pmod{4171}</math> <math>p=\text{igcd}(479080-109710,4171)</math> <math>= 43.</math> <math>q = \text{igcd}(479080+109710, 4171)</math> <math>= 97.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> =Links to related topics= [https://en.wikipedia.org/wiki/Quadratic_residue Quadratic Residue] [https://en.wikipedia.org/wiki/Modular_arithmetic Modular Arithmetic] [https://en.wikipedia.org/wiki/Leonhard_Euler Leonhard Euler,] [https://en.wikipedia.org/wiki/Euler%27s_criterion Euler's Criterion] [https://en.wikipedia.org/wiki/Adrien-Marie_Legendre Adrien-Marie Legendre,] [https://en.wikipedia.org/wiki/Legendre_symbol Legendre Symbol] [https://en.wikipedia.org/wiki/Carl_Pomerance Carl Pomerance,] [https://en.wikipedia.org/wiki/Quadratic_sieve Quadratic sieve] [https://en.wikipedia.org/wiki/Greatest_common_divisor Greatest common divisor,] [https://en.wikipedia.org/wiki/Recursion_(computer_science)#Greatest_common_divisor Greatest common divisor (Example of Recursion)] [https://docs.python.org/3.4/library/decimal.html?highlight=decimal#decimal.Context.power Python's decimal Module] ry12nyb697sy6ddzly1eg67kg271v80 2413954 2413953 2022-08-12T13:18:29Z ThaniosAkro 2805358 /* Non-trivial result */ wikitext text/x-wiki =Congruences= The subject of congruences is a field of mathematics that covers the integers, their relationship to each other and also the effect of arithmetic operations on their relationship to each other. Expressed mathematically: :<math>A \equiv B \pmod{N}</math> read as: A is congruent with B modulo N. {{RoundBoxTop|theme=2}} <math>A,B,N</math> are integers and <math>N > 1.</math> {{RoundBoxBottom}} This means that: * A modulo N equals B modulo N, * the difference, A-B, is exactly divisible by N, or * <math>A-B = K\cdot N.</math> where p modulo N or <code>p % N</code> is the remainder when p is divided by N. For example: <math>23 \equiv 8 \pmod{5}</math> because division <math>\frac{23-8}{5}</math> is exact without remainder, or <math>5\mid (23-8).</math> Similarly, <math>39 \not\equiv 29 \,\pmod{7}</math> because division <math>\frac{39-29}{7}</math> is not exact, or <math>7\nmid (39-29).</math> ==Law of addition== ===Adding a constant=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N}, </math> then: <math>A+q \equiv B+q \pmod{N}.</math> Proof: <math>A-B = K\cdot N</math>, therefore <math>A = B + K\cdot N.</math> <math>(A+q) - (B+q) = B + K\cdot N + q - B - q = K\cdot N</math> which is exactly divisible by N. {{RoundBoxBottom}} ===Adding 2 congruences=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N}, </math> and <math>C \equiv D \pmod{N}, </math> then: <math>A+C \equiv B+D \pmod{N}.</math> Proof: <math>A-B = K_1\cdot N</math>, therefore <math>A = B + K_1\cdot N</math> and <math>C = D + K_2\cdot N</math> <math>(A+C) - (B+D)</math> <math>= B + K_1\cdot N + D + K_2\cdot N - B - D</math> <math>= N(K_1 + K_2)</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of Common Congruence== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> and <math>C \equiv B \pmod{N},</math> then: <math>A \equiv C \pmod{N}.</math> Proof: <math>A = B + K_1\cdot N</math> and <math>C = B + K_2\cdot N.</math> <math>A - C = B + K_1\cdot N - B - K_2\cdot N = (K_1 - K_2)N</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of Multiplication== ===by a constant=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> then: <math>A\cdot p \equiv B\cdot p \pmod{N}.</math> Proof: <math>A\cdot p - B\cdot p = p(A-B)</math> which is exactly divisible by N. {{RoundBoxBottom}} ===by another congruence=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> and <math>C \equiv D \pmod{N},</math> then: <math>A\cdot C \equiv B\cdot D \pmod{N}.</math> Proof: <math>A = B + K_1\cdot N</math> and <math>C = D + K_2\cdot N.</math> <math>A\cdot C - B\cdot D</math> <math>= (B + K_1\cdot N)( D + K_2\cdot N) - B\cdot D</math> <math>= B\cdot D + B\cdot K_2\cdot N + K_1\cdot N\cdot D + K_1\cdot N\cdot K_2\cdot N - B\cdot D</math> <math>= N( B\cdot K_2 + K_1\cdot D + K_1\cdot K_2\cdot N )</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of squares== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> then: <math>A^2 \equiv B^2 \pmod{N}.</math> Proof: <math>A^2 - B^2 = (A+B)(A-B)</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of Division?== {{RoundBoxTop|theme=2}} A simple example shows that a "law of division" does not exist. <math>24 \equiv 14 \pmod{10}.</math> However <math>\frac{24}{2} \not\equiv \frac{14}{2} \pmod{10}</math> Because <math>12 - 7 = 5</math> is not exactly divisible by <math>10</math> {{RoundBoxBottom}} =Quadratic Congruences= A quadratic congruence is a congruence that contains at least one exact square, for example: <math>x^2 \equiv y \pmod{N}</math> or <math>x^2 \equiv y^2 \pmod{N}.</math> Initially, let us consider the congruence: <math>x^2 \equiv y \pmod{N}.</math> If <math>y = x^2 - N,</math> then: <math>x^2 \equiv y \pmod{N}.</math> Proof: <math>x^2 - y = x^2 - (x^2 - N) = N</math> which is exactly divisible by <math>N.</math> Consider an example with real numbers. Let <math>N = 257</math> and <math>26 \ge x \ge 6.</math> <syntaxhighlight> N = 257 </syntaxhighlight> {| class="wikitable" |- ! <math>x</math> !! <math>x^2 - N</math> |- | <code></code><code>6</code> || <code>-221</code> |- | <code></code><code>7</code> || <code>-208</code> |- | <code></code><code>8</code> || <code>-193</code> |- | <code></code><code>9</code> || <code>-176</code> |- | <code>10</code> || <code>-157</code> |- | <code>11</code> || <code>-136</code> |- | <code>12</code> || <code>-113</code> |- | <code>13</code> || <code></code><code>-88</code> |- | <code>14</code> || <code></code><code>-61</code> |- | <code>15</code> || <code></code><code>-32</code> |- | <code>16</code> || <code></code><code></code><code>-1</code> |- | <code>17</code> || <code></code><code></code><code>32</code> |- | <code>18</code> || <code></code><code></code><code>67</code> |- | <code>19</code> || <code></code><code>104</code> |- | <code>20</code> || <code></code><code>143</code> |- | <code>21</code> || <code></code><code>184</code> |- | <code>22</code> || <code></code><code>227</code> |- | <code>23</code> || <code></code><code>272</code> |- | <code>24</code> || <code></code><code>319</code> |- | <code>25</code> || <code></code><code>368</code> |- | <code>26</code> || <code></code><code>419</code> |} A cursory glance at the values of <math>x^2 - N</math> indicates that the value <math>x^2 - N</math> is never divisible by <math>5.</math> Proof: <math>N \equiv 2 \pmod{5}</math> therefore <math>N - 2 = k5</math> or <math>N = 5k + 2.</math> The table shows all possible values of <math>x\ %\ 5:</math> <syntaxhighlight> x | x^2 | y = x^2 - N ------ | --------------- | ----------------------------------------------- 5p + 0 | 25pp | 25pp - (5k+2) = 25pp - 5k - 2 5p + 1 | 25pp + 10p + 1 | 25pp + 10p + 1 - (5k+2) = 25pp + 10p - 5k - 1 5p + 2 | 25pp + 20p + 4 | 25pp + 20p + 4 - (5k+2) = 25pp + 20p - 5k + 2 5p + 3 | 25pp + 30p + 9 | 25pp + 30p + 9 - (5k+2) = 25pp + 30p - 5k + 7 5p + 4 | 25pp + 40p + 16 | 25pp + 40p + 16 - (5k+2) = 25pp + 40p - 5k + 14 </syntaxhighlight> As you can see, the value <math>y = x^2 - N</math> is never exactly divisible by <math>5.</math> If you look closely, you will see also that it is never exactly divisible by <math>3.</math> Why is this? An interesting question that leads us to the topic of quadratic residues. ==Quadratic Residues== Consider all the congruences for prime number <math>5:</math> <math>x^2 \equiv y \pmod{5}</math> for <math>5 > x \ge 0.</math> {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>(x^2)\ %\ 5</math> |- | <code>0</code> || <code></code><code>0</code> || <code>0</code> |- | <code>1</code> || <code></code><code>1</code> || <code>1</code> |- | <code>2</code> || <code></code><code>4</code> || <code>4</code> |- | <code>3</code> || <code></code><code>9</code> || <code>4</code> |- | <code>4</code> || <code>16</code> || <code>1</code> |} Quadratic residues of <math>5</math> are <math>0,1,4.</math> Values <math>2,3</math> are not quadratic residues of <math>5.</math> These values are quadratic non-residues. To calculate the quadratic residues of a small prime <math>p:</math> <syntaxhighlight lang=python> # python code: def quadResidues(p) : L1 = [] for v in range (p>>1, -1, -1) : L1 += [(v*v) % p] return L1 print (quadResidues(11)) </syntaxhighlight> <syntaxhighlight> [3, 5, 9, 4, 1, 0] </syntaxhighlight> Quadratic residues of <math>11</math> are <math>0,1,3,4,5,9.</math> The method presented here answers the question, "What are the quadratic residues of p?" If <math>p</math> is a very large prime, the question is often, "Is r a quadratic residue of p?" The answer is found in advanced number theory. Let us return to quadratic residues mod <math>N = 257.</math> <math>N\ %\ 5 = 2,</math> therefore <math>N</math> is not a quadratic residue of <math>5.</math> This is why <math>x^2 - N</math> is never divisible by <math>5</math> exactly. <math>N\ %\ 11 = 4,</math> therefore <math>N</math> is a quadratic residue of <math>11</math> and a value of <math>x</math> that satisfies the congruence <math>x^2 \equiv 4 \pmod{257}</math> has form <math>11p \pm 2.</math> From the table above: <syntaxhighlight> N = 257 </syntaxhighlight> {| class="wikitable" |- ! <math>x</math> !! <math>x^2\ -\ N</math> |- | <code></code><code>9</code> || <code>-176</code> |- | <code>13</code> || <code></code><code>-88</code> |- | <code>20</code> || <code></code><code>143</code> |- | <code>24</code> || <code></code><code>319</code> |} These <math>4</math> values of <math>x^2 - N</math> are exactly divisible by <math>11.</math> <math>x = 9</math> is <math>11\cdot 1 - 2.</math> <math>x = 13</math> is <math>11\cdot 1 + 2.</math> <math>x = 20</math> is <math>11\cdot 2 - 2.</math> <math>x = 24</math> is <math>11\cdot 2 + 2.</math> ===Products=== This section uses prime number <math>41</math> as an example. Using <code>quadResidues(p)</code> quadratic residues of <math>41</math> are: <syntaxhighlight> qr41 = [0, 1, 2, 4, 5, 8, 9, 10, 16, 18, 20, 21, 23, 25, 31, 32, 33, 36, 37, 39, 40] </syntaxhighlight> Quadratic non-residues of <math>41</math> are: <syntaxhighlight> qnr41 = [3, 6, 7, 11, 12, 13, 14, 15, 17, 19, 22, 24, 26, 27, 28, 29, 30, 34, 35, 38] </syntaxhighlight> ====of 2 residues==== A simple test to verify that the product of 2 residues is a residue: <syntaxhighlight lang=python> # Python code. for index1 in range (0, len(qr41)) : v1 = qr41[index1] for index2 in range (index1, len(qr41)) : v2 = qr41[index2] residue = (v1*v2) % 41 if residue not in qr41 : print ('residue',residue,'not quadratic.') </syntaxhighlight> This test shows that, at least for prime number <math>41,</math> the product of 2 residues is a residue. Advanced math proves that this is true for all primes. ====of 2 non-residues==== A simple test to verify that the product of 2 non-residues is a residue: <syntaxhighlight lang=python> # Python code. for index1 in range (0, len(qnr41)) : v1 = qnr41[index1] for index2 in range (index1, len(qnr41)) : v2 = qnr41[index2] residue = (v1*v2) % 41 if residue not in qr41 : print ('residue',residue,'not quadratic.') </syntaxhighlight> This test shows that, at least for prime number <math>41,</math> the product of 2 non-residues is a residue. Advanced math proves that this is true for all primes. ====of residue and non-residue==== A simple test to verify that the product of residue and non-residue is non-residue: <syntaxhighlight lang=python> # Python code. for index1 in range (1, len(qr41)) : v1 = qr41[index1] for index2 in range (0, len(qnr41)) : v2 = qnr41[index2] residue = (v1*v2) % 41 if residue not in qnr41 : print ('residue',residue,'quadratic.') </syntaxhighlight> This test shows that, at least for prime number <math>41,</math> the product of residue and non-residue is non-residue. Advanced math proves that this is true for all primes. {{RoundBoxTop|theme=2}} Some authors may consider <math>0</math> as not a legitimate residue. <math>0</math> is not included as a residue in the test above. {{RoundBoxBottom}} ==Euler's criterion== In number theory, '''Euler's criterion''' is a formula for determining whether or not an integer is a quadratic residue modulo a prime number. Precisely, Let ''p'' be an odd prime and ''a'' be an integer coprime to ''p''. Then :<math> a^{\tfrac{p-1}{2}} \equiv \begin{cases} \;\;\,1\pmod{p}& \text{ if there is an integer }x \text{ such that }a\equiv x^2 \pmod{p},\\ -1\pmod{p}& \text{ if there is no such integer.} \end{cases} </math> Euler's criterion can be concisely reformulated using the Legendre symbol: :<math> \left(\frac{a}{p}\right) \equiv a^{\tfrac{p-1}{2}} \pmod p. </math> :<math>\left(\frac{a}{p}\right) = \begin{cases} 1 & \text{if } a \text{ is a quadratic residue modulo } p \text{ and } a \not\equiv 0\pmod p, \\ -1 & \text{if } a \text{ is a non-quadratic residue modulo } p, \\ 0 & \text{if } a \equiv 0 \pmod p. \end{cases}</math> It is known that <math>3</math> is a quadratic residue modulo <math>11.</math> Therefore <math>(3^5)\ %\ 11</math> should be <math>1.</math> <syntaxhighlight lang=python> # python code: >>> (3**5) % 11 1 </syntaxhighlight> It is known that <math>7</math> is a quadratic non-residue modulo <math>11.</math> Therefore <math>(7^5)\ %\ 11</math> should be <math>-1.</math> <syntaxhighlight lang=python> # python code: >>> (7**5) % 11 10 </syntaxhighlight> :<math>10 \equiv -1 \pmod{11}</math> Python's decimal module provides a method for computing <math>(a^x)\ %\ p</math> very efficiently for both small and very large numbers. <syntaxhighlight lang=python> # python code: >>> import decimal >>> decimal.Context().power(3,5,11) Decimal('1') >>> decimal.Context().power(7,5,11) Decimal('10') >>> >>> a = 3456789 >>> p = 761838257287 >>> decimal.Context().power(a, p>>1, p) Decimal('761838257286') </syntaxhighlight> :<math>761838257286 \equiv -1 \pmod{761838257287}</math> Value <math>a = 3456789</math> is not a quadratic residue modulo <math>p = 761838257287.</math> {{RoundBoxTop|theme=3}} An exact square such as <math>1,4,9,16,25,\dots</math> is always a quadratic residue modulo an odd prime <math>p.</math> {{RoundBoxBottom}} ===Product of 2 residues=== Let <math>a,b</math> be quadratic residues modulo odd prime <math>p.</math> Let <math>q = \frac{p-1}{2}.</math> Then: <math>a^q \equiv 1 \pmod p</math> <math>b^q \equiv 1 \pmod p</math> By law of multiplication: <math>(a^q)(b^q) \equiv (1)(1) \pmod p</math> or <math>(a\cdot b)^q \equiv 1 \pmod p</math> Product <math>(a\cdot b)</math> of 2 quadratic residues <math>a, b</math> is quadratic residue. Similarly, product of 2 non-residues is residue, and product of residue and non-residue is non-residue. ==Factors of integer N== Several modern methods for determining the factors of a given integer attempt to create two congruent squares modulo integer <math>N.</math> <math>x^2 \equiv y^2 \pmod{N}</math> This means that the difference between the two squares is exactly divisible by <math>N</math>: <math>N\mid (x^2 - y^2).</math> Integer <math>N</math> always contains the factors <math>N,1,</math> called trivial factors. If <math>N</math> contains two non-trivial factors <math>p,q,</math> then: <math>\frac{(x+y)(x-y)}{p \cdot q}.</math> With a little luck <math>p\mid (x+y)</math> and <math>q\mid (x-y)</math> in which case: <math>p = \text{igcd}(x+y, N)</math> and <math>q = \text{igcd}(x-y, N)</math> where "<math>\text{igcd}</math>" is function "<math>\text{integer greatest common divisor.}</math>" ===A simple example:=== We will use quadratic congruences to calculate factors of <math>N = 4171</math> for <math>164 \ge x \ge 1.</math> ====Right hand side exact square==== One congruence produced an exact square for y: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 70 | 4900 | 729 |} :<math>4900 \equiv 729 \pmod{N}</math> :<math>70^2 \equiv 27^2 \pmod{N}</math> <math>p = \text{igcd}(70-27, 4171)</math> <math>= \text{igcd}(43, 4171)</math> <math>= 43.</math> <math>q = \text{igcd}(70+27, 4171)</math> <math>= \text{igcd}(97, 4171)</math> <math>= 97.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> ====Right hand side negative==== Table below contains a sample of values of <math>x</math> that produce negative <math>y:</math> {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 7 | 49 | -4122 |- | 8 | 64 | -4107 ** |- | 9 | 81 | -4090 |- | 10 | 100 | -4071 |- | 11 | 121 | -4050 !! |- | 12 | 144 | -4027 |- | 60 | 3600 | -571 |- | 61 | 3721 | -450 <math>\ \ </math>!! |- | 62 | 3844 | -327 |- | 63 | 3969 | -202 |- | 64 | 4096 | -75 <math>\ \ \ \ </math>** |} =====Non-trivial result 1===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 8 | 64 | -4107 ** |- | 64 | 4096 | -75 <math>\ \ \ \ </math>** |} :<math>64 \equiv -4107 \pmod{N}</math> :<math>4096 \equiv -75 \pmod{N}</math> :<math>64\cdot 4096 \equiv -4107\cdot (-75) \pmod{N}</math> :<math>262144 \equiv 308025 \pmod{N}</math> :<math>512^2 \equiv 555^2 \pmod{4171}</math> <math>p = \text{igcd}(555-512, 4171)</math> <math>= \text{igcd}(43, 4171)</math> <math>= 43.</math> <math>q = \text{igcd}(555+512, 4171)</math> <math>= \text{igcd}(1067, 4171)</math> <math>= 97.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> =====Non-trivial result 2===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <code>11</code> || <code></code><code>121</code> || <code>-4050</code><code>!!</code> |- | <code>61</code> || <code>3721</code> || <code></code><code>-450</code><code>!!</code> |} :<math>121 \equiv -4050 \pmod{N}</math> :<math>3721 \equiv -450 \pmod{N}</math> :<math>121\cdot 3721 \equiv -4050 \cdot (-450) \pmod{N}</math> :<math>450241 \equiv 1822500 \pmod{N}</math> :<math>671^2 \equiv 1350^2 \pmod{4171}</math> <math>p = \text{igcd}(1350-671, 4171)</math> <math>= \text{igcd}(679, 4171)</math> <math>= 97.</math> <math>q = \text{igcd}(1350+671, 4171)</math> <math>= \text{igcd}(2021, 4171)</math> <math>= 43.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> ====Right hand side positive==== Table below contains a sample of values of <math>x</math> that produce positive <math>y:</math> {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 65 | 4225 | 54 <math>\ \ \ </math>** |- | 66 | 4356 | 185 |- | 88 | 7744 | 3573 |- | 89 | 7921 | 3750 **!! |- | 90 | 8100 | 3929 |- | 144 | 20736 | 16565 |- | 145 | 21025 | 16854 <math>\ </math>!! |- | 146 | 21316 | 17145 |} =====Non-trivial result===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <code>65</code>||<code>4225</code>||<math>\ \ \ \ </math><code>54</code><math>\ \ </math><code>**</code><math>\ \ \ \ </math> |- | <code>89</code>||<code>7921</code>||<code>3750</code><math>\ \ </math><code>**!!</code> |} :<math>4225 \equiv 54 \pmod{N}</math> :<math>7921 \equiv 3750 \pmod{N}</math> :<math>4225\cdot 7921 \equiv 54 \cdot 3750 \pmod{N}</math> :<math>33466225 \equiv 202500 \pmod{N}</math> :<math>5785^2 \equiv 450^2 \pmod{4171}</math> <math>p = \text{igcd}(5785-450, 4171)</math> <math>= \text{igcd}(5335, 4171)</math> <math>= 97.</math> <math>q = \text{igcd}(5785+450, 4171)</math> <math>= \text{igcd}(6235, 4171)</math> <math>= 43.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> =====Trivial result===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <math>\ \ </math><code>89</code>||<math>\ \ </math><code>7921</code>||<math>\ \ </math><code>3750</code><math>\ \ </math><code>**!!</code> |- | <code>145</code>||<code>21025</code>||<code>16854</code><math>\ \ \ \ \ \ </math><code>!!</code> |} :<math>7921 \equiv 3750 \pmod{N}</math> :<math>21025 \equiv 16854 \pmod{N}</math> :<math>7921\cdot 21025 \equiv 3750 \cdot 16854 \pmod{N}</math> :<math>166539025 \equiv 63202500 \pmod{N}</math> :<math>12905^2 \equiv 7950^2 \pmod{4171}</math> <math>p = \text{igcd}(12905-7950, 4171)</math> <math>= \text{igcd}(4955, 4171)</math> <math>= 1.</math> <math>q = \text{igcd}(12905+7950, 4171)</math> <math>= \text{igcd}(20855, 4171)</math> <math>= 4171.</math> This congruence produced the trivial factors of <math>4171.</math> ====With 3 congruences==== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <math>\ \ </math><code>56</code>||<math>\ \ </math><code>3136</code>||<code>-1035</code> |- | <math>\ \ </math><code>59</code>||<math>\ \ </math><code>3481</code>||<math>\ \ </math><code>-690</code> |- | <code>145</code>||<code>21025</code>||<code>16854</code> |} :<math>3136 \equiv -1035 \pmod{N}</math> :<math>3481 \equiv -690 \pmod{N}</math> :<math>21025 \equiv 16854 \pmod{N}</math> :<math>3136\cdot 3481 \cdot 21025 \equiv -1035 \cdot -690 \cdot 16854 \pmod{N}</math> :<math>229517646400 \equiv 12036284100 \pmod{N}</math> :<math>479080^2 \equiv 109710^2 \pmod{4171}</math> <math>p=\text{igcd}(479080-109710,4171)</math> <math>= 43.</math> <math>q = \text{igcd}(479080+109710, 4171)</math> <math>= 97.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> =Links to related topics= [https://en.wikipedia.org/wiki/Quadratic_residue Quadratic Residue] [https://en.wikipedia.org/wiki/Modular_arithmetic Modular Arithmetic] [https://en.wikipedia.org/wiki/Leonhard_Euler Leonhard Euler,] [https://en.wikipedia.org/wiki/Euler%27s_criterion Euler's Criterion] [https://en.wikipedia.org/wiki/Adrien-Marie_Legendre Adrien-Marie Legendre,] [https://en.wikipedia.org/wiki/Legendre_symbol Legendre Symbol] [https://en.wikipedia.org/wiki/Carl_Pomerance Carl Pomerance,] [https://en.wikipedia.org/wiki/Quadratic_sieve Quadratic sieve] [https://en.wikipedia.org/wiki/Greatest_common_divisor Greatest common divisor,] [https://en.wikipedia.org/wiki/Recursion_(computer_science)#Greatest_common_divisor Greatest common divisor (Example of Recursion)] [https://docs.python.org/3.4/library/decimal.html?highlight=decimal#decimal.Context.power Python's decimal Module] jfbxnbez4qf1r952kfy0fs5pwa0wgjr 2413955 2413954 2022-08-12T13:24:09Z ThaniosAkro 2805358 /* Right hand side positive */ wikitext text/x-wiki =Congruences= The subject of congruences is a field of mathematics that covers the integers, their relationship to each other and also the effect of arithmetic operations on their relationship to each other. Expressed mathematically: :<math>A \equiv B \pmod{N}</math> read as: A is congruent with B modulo N. {{RoundBoxTop|theme=2}} <math>A,B,N</math> are integers and <math>N > 1.</math> {{RoundBoxBottom}} This means that: * A modulo N equals B modulo N, * the difference, A-B, is exactly divisible by N, or * <math>A-B = K\cdot N.</math> where p modulo N or <code>p % N</code> is the remainder when p is divided by N. For example: <math>23 \equiv 8 \pmod{5}</math> because division <math>\frac{23-8}{5}</math> is exact without remainder, or <math>5\mid (23-8).</math> Similarly, <math>39 \not\equiv 29 \,\pmod{7}</math> because division <math>\frac{39-29}{7}</math> is not exact, or <math>7\nmid (39-29).</math> ==Law of addition== ===Adding a constant=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N}, </math> then: <math>A+q \equiv B+q \pmod{N}.</math> Proof: <math>A-B = K\cdot N</math>, therefore <math>A = B + K\cdot N.</math> <math>(A+q) - (B+q) = B + K\cdot N + q - B - q = K\cdot N</math> which is exactly divisible by N. {{RoundBoxBottom}} ===Adding 2 congruences=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N}, </math> and <math>C \equiv D \pmod{N}, </math> then: <math>A+C \equiv B+D \pmod{N}.</math> Proof: <math>A-B = K_1\cdot N</math>, therefore <math>A = B + K_1\cdot N</math> and <math>C = D + K_2\cdot N</math> <math>(A+C) - (B+D)</math> <math>= B + K_1\cdot N + D + K_2\cdot N - B - D</math> <math>= N(K_1 + K_2)</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of Common Congruence== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> and <math>C \equiv B \pmod{N},</math> then: <math>A \equiv C \pmod{N}.</math> Proof: <math>A = B + K_1\cdot N</math> and <math>C = B + K_2\cdot N.</math> <math>A - C = B + K_1\cdot N - B - K_2\cdot N = (K_1 - K_2)N</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of Multiplication== ===by a constant=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> then: <math>A\cdot p \equiv B\cdot p \pmod{N}.</math> Proof: <math>A\cdot p - B\cdot p = p(A-B)</math> which is exactly divisible by N. {{RoundBoxBottom}} ===by another congruence=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> and <math>C \equiv D \pmod{N},</math> then: <math>A\cdot C \equiv B\cdot D \pmod{N}.</math> Proof: <math>A = B + K_1\cdot N</math> and <math>C = D + K_2\cdot N.</math> <math>A\cdot C - B\cdot D</math> <math>= (B + K_1\cdot N)( D + K_2\cdot N) - B\cdot D</math> <math>= B\cdot D + B\cdot K_2\cdot N + K_1\cdot N\cdot D + K_1\cdot N\cdot K_2\cdot N - B\cdot D</math> <math>= N( B\cdot K_2 + K_1\cdot D + K_1\cdot K_2\cdot N )</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of squares== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> then: <math>A^2 \equiv B^2 \pmod{N}.</math> Proof: <math>A^2 - B^2 = (A+B)(A-B)</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of Division?== {{RoundBoxTop|theme=2}} A simple example shows that a "law of division" does not exist. <math>24 \equiv 14 \pmod{10}.</math> However <math>\frac{24}{2} \not\equiv \frac{14}{2} \pmod{10}</math> Because <math>12 - 7 = 5</math> is not exactly divisible by <math>10</math> {{RoundBoxBottom}} =Quadratic Congruences= A quadratic congruence is a congruence that contains at least one exact square, for example: <math>x^2 \equiv y \pmod{N}</math> or <math>x^2 \equiv y^2 \pmod{N}.</math> Initially, let us consider the congruence: <math>x^2 \equiv y \pmod{N}.</math> If <math>y = x^2 - N,</math> then: <math>x^2 \equiv y \pmod{N}.</math> Proof: <math>x^2 - y = x^2 - (x^2 - N) = N</math> which is exactly divisible by <math>N.</math> Consider an example with real numbers. Let <math>N = 257</math> and <math>26 \ge x \ge 6.</math> <syntaxhighlight> N = 257 </syntaxhighlight> {| class="wikitable" |- ! <math>x</math> !! <math>x^2 - N</math> |- | <code></code><code>6</code> || <code>-221</code> |- | <code></code><code>7</code> || <code>-208</code> |- | <code></code><code>8</code> || <code>-193</code> |- | <code></code><code>9</code> || <code>-176</code> |- | <code>10</code> || <code>-157</code> |- | <code>11</code> || <code>-136</code> |- | <code>12</code> || <code>-113</code> |- | <code>13</code> || <code></code><code>-88</code> |- | <code>14</code> || <code></code><code>-61</code> |- | <code>15</code> || <code></code><code>-32</code> |- | <code>16</code> || <code></code><code></code><code>-1</code> |- | <code>17</code> || <code></code><code></code><code>32</code> |- | <code>18</code> || <code></code><code></code><code>67</code> |- | <code>19</code> || <code></code><code>104</code> |- | <code>20</code> || <code></code><code>143</code> |- | <code>21</code> || <code></code><code>184</code> |- | <code>22</code> || <code></code><code>227</code> |- | <code>23</code> || <code></code><code>272</code> |- | <code>24</code> || <code></code><code>319</code> |- | <code>25</code> || <code></code><code>368</code> |- | <code>26</code> || <code></code><code>419</code> |} A cursory glance at the values of <math>x^2 - N</math> indicates that the value <math>x^2 - N</math> is never divisible by <math>5.</math> Proof: <math>N \equiv 2 \pmod{5}</math> therefore <math>N - 2 = k5</math> or <math>N = 5k + 2.</math> The table shows all possible values of <math>x\ %\ 5:</math> <syntaxhighlight> x | x^2 | y = x^2 - N ------ | --------------- | ----------------------------------------------- 5p + 0 | 25pp | 25pp - (5k+2) = 25pp - 5k - 2 5p + 1 | 25pp + 10p + 1 | 25pp + 10p + 1 - (5k+2) = 25pp + 10p - 5k - 1 5p + 2 | 25pp + 20p + 4 | 25pp + 20p + 4 - (5k+2) = 25pp + 20p - 5k + 2 5p + 3 | 25pp + 30p + 9 | 25pp + 30p + 9 - (5k+2) = 25pp + 30p - 5k + 7 5p + 4 | 25pp + 40p + 16 | 25pp + 40p + 16 - (5k+2) = 25pp + 40p - 5k + 14 </syntaxhighlight> As you can see, the value <math>y = x^2 - N</math> is never exactly divisible by <math>5.</math> If you look closely, you will see also that it is never exactly divisible by <math>3.</math> Why is this? An interesting question that leads us to the topic of quadratic residues. ==Quadratic Residues== Consider all the congruences for prime number <math>5:</math> <math>x^2 \equiv y \pmod{5}</math> for <math>5 > x \ge 0.</math> {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>(x^2)\ %\ 5</math> |- | <code>0</code> || <code></code><code>0</code> || <code>0</code> |- | <code>1</code> || <code></code><code>1</code> || <code>1</code> |- | <code>2</code> || <code></code><code>4</code> || <code>4</code> |- | <code>3</code> || <code></code><code>9</code> || <code>4</code> |- | <code>4</code> || <code>16</code> || <code>1</code> |} Quadratic residues of <math>5</math> are <math>0,1,4.</math> Values <math>2,3</math> are not quadratic residues of <math>5.</math> These values are quadratic non-residues. To calculate the quadratic residues of a small prime <math>p:</math> <syntaxhighlight lang=python> # python code: def quadResidues(p) : L1 = [] for v in range (p>>1, -1, -1) : L1 += [(v*v) % p] return L1 print (quadResidues(11)) </syntaxhighlight> <syntaxhighlight> [3, 5, 9, 4, 1, 0] </syntaxhighlight> Quadratic residues of <math>11</math> are <math>0,1,3,4,5,9.</math> The method presented here answers the question, "What are the quadratic residues of p?" If <math>p</math> is a very large prime, the question is often, "Is r a quadratic residue of p?" The answer is found in advanced number theory. Let us return to quadratic residues mod <math>N = 257.</math> <math>N\ %\ 5 = 2,</math> therefore <math>N</math> is not a quadratic residue of <math>5.</math> This is why <math>x^2 - N</math> is never divisible by <math>5</math> exactly. <math>N\ %\ 11 = 4,</math> therefore <math>N</math> is a quadratic residue of <math>11</math> and a value of <math>x</math> that satisfies the congruence <math>x^2 \equiv 4 \pmod{257}</math> has form <math>11p \pm 2.</math> From the table above: <syntaxhighlight> N = 257 </syntaxhighlight> {| class="wikitable" |- ! <math>x</math> !! <math>x^2\ -\ N</math> |- | <code></code><code>9</code> || <code>-176</code> |- | <code>13</code> || <code></code><code>-88</code> |- | <code>20</code> || <code></code><code>143</code> |- | <code>24</code> || <code></code><code>319</code> |} These <math>4</math> values of <math>x^2 - N</math> are exactly divisible by <math>11.</math> <math>x = 9</math> is <math>11\cdot 1 - 2.</math> <math>x = 13</math> is <math>11\cdot 1 + 2.</math> <math>x = 20</math> is <math>11\cdot 2 - 2.</math> <math>x = 24</math> is <math>11\cdot 2 + 2.</math> ===Products=== This section uses prime number <math>41</math> as an example. Using <code>quadResidues(p)</code> quadratic residues of <math>41</math> are: <syntaxhighlight> qr41 = [0, 1, 2, 4, 5, 8, 9, 10, 16, 18, 20, 21, 23, 25, 31, 32, 33, 36, 37, 39, 40] </syntaxhighlight> Quadratic non-residues of <math>41</math> are: <syntaxhighlight> qnr41 = [3, 6, 7, 11, 12, 13, 14, 15, 17, 19, 22, 24, 26, 27, 28, 29, 30, 34, 35, 38] </syntaxhighlight> ====of 2 residues==== A simple test to verify that the product of 2 residues is a residue: <syntaxhighlight lang=python> # Python code. for index1 in range (0, len(qr41)) : v1 = qr41[index1] for index2 in range (index1, len(qr41)) : v2 = qr41[index2] residue = (v1*v2) % 41 if residue not in qr41 : print ('residue',residue,'not quadratic.') </syntaxhighlight> This test shows that, at least for prime number <math>41,</math> the product of 2 residues is a residue. Advanced math proves that this is true for all primes. ====of 2 non-residues==== A simple test to verify that the product of 2 non-residues is a residue: <syntaxhighlight lang=python> # Python code. for index1 in range (0, len(qnr41)) : v1 = qnr41[index1] for index2 in range (index1, len(qnr41)) : v2 = qnr41[index2] residue = (v1*v2) % 41 if residue not in qr41 : print ('residue',residue,'not quadratic.') </syntaxhighlight> This test shows that, at least for prime number <math>41,</math> the product of 2 non-residues is a residue. Advanced math proves that this is true for all primes. ====of residue and non-residue==== A simple test to verify that the product of residue and non-residue is non-residue: <syntaxhighlight lang=python> # Python code. for index1 in range (1, len(qr41)) : v1 = qr41[index1] for index2 in range (0, len(qnr41)) : v2 = qnr41[index2] residue = (v1*v2) % 41 if residue not in qnr41 : print ('residue',residue,'quadratic.') </syntaxhighlight> This test shows that, at least for prime number <math>41,</math> the product of residue and non-residue is non-residue. Advanced math proves that this is true for all primes. {{RoundBoxTop|theme=2}} Some authors may consider <math>0</math> as not a legitimate residue. <math>0</math> is not included as a residue in the test above. {{RoundBoxBottom}} ==Euler's criterion== In number theory, '''Euler's criterion''' is a formula for determining whether or not an integer is a quadratic residue modulo a prime number. Precisely, Let ''p'' be an odd prime and ''a'' be an integer coprime to ''p''. Then :<math> a^{\tfrac{p-1}{2}} \equiv \begin{cases} \;\;\,1\pmod{p}& \text{ if there is an integer }x \text{ such that }a\equiv x^2 \pmod{p},\\ -1\pmod{p}& \text{ if there is no such integer.} \end{cases} </math> Euler's criterion can be concisely reformulated using the Legendre symbol: :<math> \left(\frac{a}{p}\right) \equiv a^{\tfrac{p-1}{2}} \pmod p. </math> :<math>\left(\frac{a}{p}\right) = \begin{cases} 1 & \text{if } a \text{ is a quadratic residue modulo } p \text{ and } a \not\equiv 0\pmod p, \\ -1 & \text{if } a \text{ is a non-quadratic residue modulo } p, \\ 0 & \text{if } a \equiv 0 \pmod p. \end{cases}</math> It is known that <math>3</math> is a quadratic residue modulo <math>11.</math> Therefore <math>(3^5)\ %\ 11</math> should be <math>1.</math> <syntaxhighlight lang=python> # python code: >>> (3**5) % 11 1 </syntaxhighlight> It is known that <math>7</math> is a quadratic non-residue modulo <math>11.</math> Therefore <math>(7^5)\ %\ 11</math> should be <math>-1.</math> <syntaxhighlight lang=python> # python code: >>> (7**5) % 11 10 </syntaxhighlight> :<math>10 \equiv -1 \pmod{11}</math> Python's decimal module provides a method for computing <math>(a^x)\ %\ p</math> very efficiently for both small and very large numbers. <syntaxhighlight lang=python> # python code: >>> import decimal >>> decimal.Context().power(3,5,11) Decimal('1') >>> decimal.Context().power(7,5,11) Decimal('10') >>> >>> a = 3456789 >>> p = 761838257287 >>> decimal.Context().power(a, p>>1, p) Decimal('761838257286') </syntaxhighlight> :<math>761838257286 \equiv -1 \pmod{761838257287}</math> Value <math>a = 3456789</math> is not a quadratic residue modulo <math>p = 761838257287.</math> {{RoundBoxTop|theme=3}} An exact square such as <math>1,4,9,16,25,\dots</math> is always a quadratic residue modulo an odd prime <math>p.</math> {{RoundBoxBottom}} ===Product of 2 residues=== Let <math>a,b</math> be quadratic residues modulo odd prime <math>p.</math> Let <math>q = \frac{p-1}{2}.</math> Then: <math>a^q \equiv 1 \pmod p</math> <math>b^q \equiv 1 \pmod p</math> By law of multiplication: <math>(a^q)(b^q) \equiv (1)(1) \pmod p</math> or <math>(a\cdot b)^q \equiv 1 \pmod p</math> Product <math>(a\cdot b)</math> of 2 quadratic residues <math>a, b</math> is quadratic residue. Similarly, product of 2 non-residues is residue, and product of residue and non-residue is non-residue. ==Factors of integer N== Several modern methods for determining the factors of a given integer attempt to create two congruent squares modulo integer <math>N.</math> <math>x^2 \equiv y^2 \pmod{N}</math> This means that the difference between the two squares is exactly divisible by <math>N</math>: <math>N\mid (x^2 - y^2).</math> Integer <math>N</math> always contains the factors <math>N,1,</math> called trivial factors. If <math>N</math> contains two non-trivial factors <math>p,q,</math> then: <math>\frac{(x+y)(x-y)}{p \cdot q}.</math> With a little luck <math>p\mid (x+y)</math> and <math>q\mid (x-y)</math> in which case: <math>p = \text{igcd}(x+y, N)</math> and <math>q = \text{igcd}(x-y, N)</math> where "<math>\text{igcd}</math>" is function "<math>\text{integer greatest common divisor.}</math>" ===A simple example:=== We will use quadratic congruences to calculate factors of <math>N = 4171</math> for <math>164 \ge x \ge 1.</math> ====Right hand side exact square==== One congruence produced an exact square for y: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 70 | 4900 | 729 |} :<math>4900 \equiv 729 \pmod{N}</math> :<math>70^2 \equiv 27^2 \pmod{N}</math> <math>p = \text{igcd}(70-27, 4171)</math> <math>= \text{igcd}(43, 4171)</math> <math>= 43.</math> <math>q = \text{igcd}(70+27, 4171)</math> <math>= \text{igcd}(97, 4171)</math> <math>= 97.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> ====Right hand side negative==== Table below contains a sample of values of <math>x</math> that produce negative <math>y:</math> {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 7 | 49 | -4122 |- | 8 | 64 | -4107 ** |- | 9 | 81 | -4090 |- | 10 | 100 | -4071 |- | 11 | 121 | -4050 !! |- | 12 | 144 | -4027 |- | 60 | 3600 | -571 |- | 61 | 3721 | -450 <math>\ \ </math>!! |- | 62 | 3844 | -327 |- | 63 | 3969 | -202 |- | 64 | 4096 | -75 <math>\ \ \ \ </math>** |} =====Non-trivial result 1===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 8 | 64 | -4107 ** |- | 64 | 4096 | -75 <math>\ \ \ \ </math>** |} :<math>64 \equiv -4107 \pmod{N}</math> :<math>4096 \equiv -75 \pmod{N}</math> :<math>64\cdot 4096 \equiv -4107\cdot (-75) \pmod{N}</math> :<math>262144 \equiv 308025 \pmod{N}</math> :<math>512^2 \equiv 555^2 \pmod{4171}</math> <math>p = \text{igcd}(555-512, 4171)</math> <math>= \text{igcd}(43, 4171)</math> <math>= 43.</math> <math>q = \text{igcd}(555+512, 4171)</math> <math>= \text{igcd}(1067, 4171)</math> <math>= 97.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> =====Non-trivial result 2===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <code>11</code> || <code></code><code>121</code> || <code>-4050</code><code>!!</code> |- | <code>61</code> || <code>3721</code> || <code></code><code>-450</code><code>!!</code> |} :<math>121 \equiv -4050 \pmod{N}</math> :<math>3721 \equiv -450 \pmod{N}</math> :<math>121\cdot 3721 \equiv -4050 \cdot (-450) \pmod{N}</math> :<math>450241 \equiv 1822500 \pmod{N}</math> :<math>671^2 \equiv 1350^2 \pmod{4171}</math> <math>p = \text{igcd}(1350-671, 4171)</math> <math>= \text{igcd}(679, 4171)</math> <math>= 97.</math> <math>q = \text{igcd}(1350+671, 4171)</math> <math>= \text{igcd}(2021, 4171)</math> <math>= 43.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> ====Right hand side positive==== Table below contains a sample of values of <math>x</math> that produce positive <math>y:</math> {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <math>\ \ </math><code>65</code>||<math>\ \ </math><code>4225</code>||<math>\ \ \ \ \ \ </math><code>54</code><math>\ \ </math><code>**</code><math>\ \ \ \ </math> |- | <math>\ \ </math><code>66</code>||<math>\ \ </math><code>4356</code>||<math>\ \ \ \ </math><code>185</code><math>\ \ \ \ \ \ \ \ \ \ </math> |- | <math>\ \ </math><code>88</code>||<math>\ \ </math><code>7744</code>||<math>\ \ </math><code>3573</code><math>\ \ \ \ \ \ \ \ \ \ </math> |- | <math>\ \ </math><code>89</code>||<math>\ \ </math><code>7921</code>||<math>\ \ </math><code>3750</code><math>\ \ </math><code>**!!</code> |- | <math>\ \ </math><code>90</code>||<math>\ \ </math><code>8100</code>||<math>\ \ </math><code>3929</code><math>\ \ \ \ \ \ \ \ \ \ </math> |- | <code>144</code>||<code>20736</code>||<code>16565</code><math>\ \ \ \ \ \ \ \ \ \ </math> |- | <code>145</code>||<code>21025</code>||<code>16854</code><math>\ \ \ \ \ \ </math><code>!!</code> |- | <code>146</code>||<code>21316</code>||<code>17145</code><math>\ \ \ \ \ \ \ \ \ \ </math> |} =====Non-trivial result===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <code>65</code>||<code>4225</code>||<math>\ \ \ \ </math><code>54</code><math>\ \ </math><code>**</code><math>\ \ \ \ </math> |- | <code>89</code>||<code>7921</code>||<code>3750</code><math>\ \ </math><code>**!!</code> |} :<math>4225 \equiv 54 \pmod{N}</math> :<math>7921 \equiv 3750 \pmod{N}</math> :<math>4225\cdot 7921 \equiv 54 \cdot 3750 \pmod{N}</math> :<math>33466225 \equiv 202500 \pmod{N}</math> :<math>5785^2 \equiv 450^2 \pmod{4171}</math> <math>p = \text{igcd}(5785-450, 4171)</math> <math>= \text{igcd}(5335, 4171)</math> <math>= 97.</math> <math>q = \text{igcd}(5785+450, 4171)</math> <math>= \text{igcd}(6235, 4171)</math> <math>= 43.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> =====Trivial result===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <math>\ \ </math><code>89</code>||<math>\ \ </math><code>7921</code>||<math>\ \ </math><code>3750</code><math>\ \ </math><code>**!!</code> |- | <code>145</code>||<code>21025</code>||<code>16854</code><math>\ \ \ \ \ \ </math><code>!!</code> |} :<math>7921 \equiv 3750 \pmod{N}</math> :<math>21025 \equiv 16854 \pmod{N}</math> :<math>7921\cdot 21025 \equiv 3750 \cdot 16854 \pmod{N}</math> :<math>166539025 \equiv 63202500 \pmod{N}</math> :<math>12905^2 \equiv 7950^2 \pmod{4171}</math> <math>p = \text{igcd}(12905-7950, 4171)</math> <math>= \text{igcd}(4955, 4171)</math> <math>= 1.</math> <math>q = \text{igcd}(12905+7950, 4171)</math> <math>= \text{igcd}(20855, 4171)</math> <math>= 4171.</math> This congruence produced the trivial factors of <math>4171.</math> ====With 3 congruences==== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <math>\ \ </math><code>56</code>||<math>\ \ </math><code>3136</code>||<code>-1035</code> |- | <math>\ \ </math><code>59</code>||<math>\ \ </math><code>3481</code>||<math>\ \ </math><code>-690</code> |- | <code>145</code>||<code>21025</code>||<code>16854</code> |} :<math>3136 \equiv -1035 \pmod{N}</math> :<math>3481 \equiv -690 \pmod{N}</math> :<math>21025 \equiv 16854 \pmod{N}</math> :<math>3136\cdot 3481 \cdot 21025 \equiv -1035 \cdot -690 \cdot 16854 \pmod{N}</math> :<math>229517646400 \equiv 12036284100 \pmod{N}</math> :<math>479080^2 \equiv 109710^2 \pmod{4171}</math> <math>p=\text{igcd}(479080-109710,4171)</math> <math>= 43.</math> <math>q = \text{igcd}(479080+109710, 4171)</math> <math>= 97.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> =Links to related topics= [https://en.wikipedia.org/wiki/Quadratic_residue Quadratic Residue] [https://en.wikipedia.org/wiki/Modular_arithmetic Modular Arithmetic] [https://en.wikipedia.org/wiki/Leonhard_Euler Leonhard Euler,] [https://en.wikipedia.org/wiki/Euler%27s_criterion Euler's Criterion] [https://en.wikipedia.org/wiki/Adrien-Marie_Legendre Adrien-Marie Legendre,] [https://en.wikipedia.org/wiki/Legendre_symbol Legendre Symbol] [https://en.wikipedia.org/wiki/Carl_Pomerance Carl Pomerance,] [https://en.wikipedia.org/wiki/Quadratic_sieve Quadratic sieve] [https://en.wikipedia.org/wiki/Greatest_common_divisor Greatest common divisor,] [https://en.wikipedia.org/wiki/Recursion_(computer_science)#Greatest_common_divisor Greatest common divisor (Example of Recursion)] [https://docs.python.org/3.4/library/decimal.html?highlight=decimal#decimal.Context.power Python's decimal Module] j91rf6vspzbhi4s5v86b9j9etdgf018 2413956 2413955 2022-08-12T13:54:35Z ThaniosAkro 2805358 /* Right hand side negative */ wikitext text/x-wiki =Congruences= The subject of congruences is a field of mathematics that covers the integers, their relationship to each other and also the effect of arithmetic operations on their relationship to each other. Expressed mathematically: :<math>A \equiv B \pmod{N}</math> read as: A is congruent with B modulo N. {{RoundBoxTop|theme=2}} <math>A,B,N</math> are integers and <math>N > 1.</math> {{RoundBoxBottom}} This means that: * A modulo N equals B modulo N, * the difference, A-B, is exactly divisible by N, or * <math>A-B = K\cdot N.</math> where p modulo N or <code>p % N</code> is the remainder when p is divided by N. For example: <math>23 \equiv 8 \pmod{5}</math> because division <math>\frac{23-8}{5}</math> is exact without remainder, or <math>5\mid (23-8).</math> Similarly, <math>39 \not\equiv 29 \,\pmod{7}</math> because division <math>\frac{39-29}{7}</math> is not exact, or <math>7\nmid (39-29).</math> ==Law of addition== ===Adding a constant=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N}, </math> then: <math>A+q \equiv B+q \pmod{N}.</math> Proof: <math>A-B = K\cdot N</math>, therefore <math>A = B + K\cdot N.</math> <math>(A+q) - (B+q) = B + K\cdot N + q - B - q = K\cdot N</math> which is exactly divisible by N. {{RoundBoxBottom}} ===Adding 2 congruences=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N}, </math> and <math>C \equiv D \pmod{N}, </math> then: <math>A+C \equiv B+D \pmod{N}.</math> Proof: <math>A-B = K_1\cdot N</math>, therefore <math>A = B + K_1\cdot N</math> and <math>C = D + K_2\cdot N</math> <math>(A+C) - (B+D)</math> <math>= B + K_1\cdot N + D + K_2\cdot N - B - D</math> <math>= N(K_1 + K_2)</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of Common Congruence== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> and <math>C \equiv B \pmod{N},</math> then: <math>A \equiv C \pmod{N}.</math> Proof: <math>A = B + K_1\cdot N</math> and <math>C = B + K_2\cdot N.</math> <math>A - C = B + K_1\cdot N - B - K_2\cdot N = (K_1 - K_2)N</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of Multiplication== ===by a constant=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> then: <math>A\cdot p \equiv B\cdot p \pmod{N}.</math> Proof: <math>A\cdot p - B\cdot p = p(A-B)</math> which is exactly divisible by N. {{RoundBoxBottom}} ===by another congruence=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> and <math>C \equiv D \pmod{N},</math> then: <math>A\cdot C \equiv B\cdot D \pmod{N}.</math> Proof: <math>A = B + K_1\cdot N</math> and <math>C = D + K_2\cdot N.</math> <math>A\cdot C - B\cdot D</math> <math>= (B + K_1\cdot N)( D + K_2\cdot N) - B\cdot D</math> <math>= B\cdot D + B\cdot K_2\cdot N + K_1\cdot N\cdot D + K_1\cdot N\cdot K_2\cdot N - B\cdot D</math> <math>= N( B\cdot K_2 + K_1\cdot D + K_1\cdot K_2\cdot N )</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of squares== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> then: <math>A^2 \equiv B^2 \pmod{N}.</math> Proof: <math>A^2 - B^2 = (A+B)(A-B)</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of Division?== {{RoundBoxTop|theme=2}} A simple example shows that a "law of division" does not exist. <math>24 \equiv 14 \pmod{10}.</math> However <math>\frac{24}{2} \not\equiv \frac{14}{2} \pmod{10}</math> Because <math>12 - 7 = 5</math> is not exactly divisible by <math>10</math> {{RoundBoxBottom}} =Quadratic Congruences= A quadratic congruence is a congruence that contains at least one exact square, for example: <math>x^2 \equiv y \pmod{N}</math> or <math>x^2 \equiv y^2 \pmod{N}.</math> Initially, let us consider the congruence: <math>x^2 \equiv y \pmod{N}.</math> If <math>y = x^2 - N,</math> then: <math>x^2 \equiv y \pmod{N}.</math> Proof: <math>x^2 - y = x^2 - (x^2 - N) = N</math> which is exactly divisible by <math>N.</math> Consider an example with real numbers. Let <math>N = 257</math> and <math>26 \ge x \ge 6.</math> <syntaxhighlight> N = 257 </syntaxhighlight> {| class="wikitable" |- ! <math>x</math> !! <math>x^2 - N</math> |- | <code></code><code>6</code> || <code>-221</code> |- | <code></code><code>7</code> || <code>-208</code> |- | <code></code><code>8</code> || <code>-193</code> |- | <code></code><code>9</code> || <code>-176</code> |- | <code>10</code> || <code>-157</code> |- | <code>11</code> || <code>-136</code> |- | <code>12</code> || <code>-113</code> |- | <code>13</code> || <code></code><code>-88</code> |- | <code>14</code> || <code></code><code>-61</code> |- | <code>15</code> || <code></code><code>-32</code> |- | <code>16</code> || <code></code><code></code><code>-1</code> |- | <code>17</code> || <code></code><code></code><code>32</code> |- | <code>18</code> || <code></code><code></code><code>67</code> |- | <code>19</code> || <code></code><code>104</code> |- | <code>20</code> || <code></code><code>143</code> |- | <code>21</code> || <code></code><code>184</code> |- | <code>22</code> || <code></code><code>227</code> |- | <code>23</code> || <code></code><code>272</code> |- | <code>24</code> || <code></code><code>319</code> |- | <code>25</code> || <code></code><code>368</code> |- | <code>26</code> || <code></code><code>419</code> |} A cursory glance at the values of <math>x^2 - N</math> indicates that the value <math>x^2 - N</math> is never divisible by <math>5.</math> Proof: <math>N \equiv 2 \pmod{5}</math> therefore <math>N - 2 = k5</math> or <math>N = 5k + 2.</math> The table shows all possible values of <math>x\ %\ 5:</math> <syntaxhighlight> x | x^2 | y = x^2 - N ------ | --------------- | ----------------------------------------------- 5p + 0 | 25pp | 25pp - (5k+2) = 25pp - 5k - 2 5p + 1 | 25pp + 10p + 1 | 25pp + 10p + 1 - (5k+2) = 25pp + 10p - 5k - 1 5p + 2 | 25pp + 20p + 4 | 25pp + 20p + 4 - (5k+2) = 25pp + 20p - 5k + 2 5p + 3 | 25pp + 30p + 9 | 25pp + 30p + 9 - (5k+2) = 25pp + 30p - 5k + 7 5p + 4 | 25pp + 40p + 16 | 25pp + 40p + 16 - (5k+2) = 25pp + 40p - 5k + 14 </syntaxhighlight> As you can see, the value <math>y = x^2 - N</math> is never exactly divisible by <math>5.</math> If you look closely, you will see also that it is never exactly divisible by <math>3.</math> Why is this? An interesting question that leads us to the topic of quadratic residues. ==Quadratic Residues== Consider all the congruences for prime number <math>5:</math> <math>x^2 \equiv y \pmod{5}</math> for <math>5 > x \ge 0.</math> {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>(x^2)\ %\ 5</math> |- | <code>0</code> || <code></code><code>0</code> || <code>0</code> |- | <code>1</code> || <code></code><code>1</code> || <code>1</code> |- | <code>2</code> || <code></code><code>4</code> || <code>4</code> |- | <code>3</code> || <code></code><code>9</code> || <code>4</code> |- | <code>4</code> || <code>16</code> || <code>1</code> |} Quadratic residues of <math>5</math> are <math>0,1,4.</math> Values <math>2,3</math> are not quadratic residues of <math>5.</math> These values are quadratic non-residues. To calculate the quadratic residues of a small prime <math>p:</math> <syntaxhighlight lang=python> # python code: def quadResidues(p) : L1 = [] for v in range (p>>1, -1, -1) : L1 += [(v*v) % p] return L1 print (quadResidues(11)) </syntaxhighlight> <syntaxhighlight> [3, 5, 9, 4, 1, 0] </syntaxhighlight> Quadratic residues of <math>11</math> are <math>0,1,3,4,5,9.</math> The method presented here answers the question, "What are the quadratic residues of p?" If <math>p</math> is a very large prime, the question is often, "Is r a quadratic residue of p?" The answer is found in advanced number theory. Let us return to quadratic residues mod <math>N = 257.</math> <math>N\ %\ 5 = 2,</math> therefore <math>N</math> is not a quadratic residue of <math>5.</math> This is why <math>x^2 - N</math> is never divisible by <math>5</math> exactly. <math>N\ %\ 11 = 4,</math> therefore <math>N</math> is a quadratic residue of <math>11</math> and a value of <math>x</math> that satisfies the congruence <math>x^2 \equiv 4 \pmod{257}</math> has form <math>11p \pm 2.</math> From the table above: <syntaxhighlight> N = 257 </syntaxhighlight> {| class="wikitable" |- ! <math>x</math> !! <math>x^2\ -\ N</math> |- | <code></code><code>9</code> || <code>-176</code> |- | <code>13</code> || <code></code><code>-88</code> |- | <code>20</code> || <code></code><code>143</code> |- | <code>24</code> || <code></code><code>319</code> |} These <math>4</math> values of <math>x^2 - N</math> are exactly divisible by <math>11.</math> <math>x = 9</math> is <math>11\cdot 1 - 2.</math> <math>x = 13</math> is <math>11\cdot 1 + 2.</math> <math>x = 20</math> is <math>11\cdot 2 - 2.</math> <math>x = 24</math> is <math>11\cdot 2 + 2.</math> ===Products=== This section uses prime number <math>41</math> as an example. Using <code>quadResidues(p)</code> quadratic residues of <math>41</math> are: <syntaxhighlight> qr41 = [0, 1, 2, 4, 5, 8, 9, 10, 16, 18, 20, 21, 23, 25, 31, 32, 33, 36, 37, 39, 40] </syntaxhighlight> Quadratic non-residues of <math>41</math> are: <syntaxhighlight> qnr41 = [3, 6, 7, 11, 12, 13, 14, 15, 17, 19, 22, 24, 26, 27, 28, 29, 30, 34, 35, 38] </syntaxhighlight> ====of 2 residues==== A simple test to verify that the product of 2 residues is a residue: <syntaxhighlight lang=python> # Python code. for index1 in range (0, len(qr41)) : v1 = qr41[index1] for index2 in range (index1, len(qr41)) : v2 = qr41[index2] residue = (v1*v2) % 41 if residue not in qr41 : print ('residue',residue,'not quadratic.') </syntaxhighlight> This test shows that, at least for prime number <math>41,</math> the product of 2 residues is a residue. Advanced math proves that this is true for all primes. ====of 2 non-residues==== A simple test to verify that the product of 2 non-residues is a residue: <syntaxhighlight lang=python> # Python code. for index1 in range (0, len(qnr41)) : v1 = qnr41[index1] for index2 in range (index1, len(qnr41)) : v2 = qnr41[index2] residue = (v1*v2) % 41 if residue not in qr41 : print ('residue',residue,'not quadratic.') </syntaxhighlight> This test shows that, at least for prime number <math>41,</math> the product of 2 non-residues is a residue. Advanced math proves that this is true for all primes. ====of residue and non-residue==== A simple test to verify that the product of residue and non-residue is non-residue: <syntaxhighlight lang=python> # Python code. for index1 in range (1, len(qr41)) : v1 = qr41[index1] for index2 in range (0, len(qnr41)) : v2 = qnr41[index2] residue = (v1*v2) % 41 if residue not in qnr41 : print ('residue',residue,'quadratic.') </syntaxhighlight> This test shows that, at least for prime number <math>41,</math> the product of residue and non-residue is non-residue. Advanced math proves that this is true for all primes. {{RoundBoxTop|theme=2}} Some authors may consider <math>0</math> as not a legitimate residue. <math>0</math> is not included as a residue in the test above. {{RoundBoxBottom}} ==Euler's criterion== In number theory, '''Euler's criterion''' is a formula for determining whether or not an integer is a quadratic residue modulo a prime number. Precisely, Let ''p'' be an odd prime and ''a'' be an integer coprime to ''p''. Then :<math> a^{\tfrac{p-1}{2}} \equiv \begin{cases} \;\;\,1\pmod{p}& \text{ if there is an integer }x \text{ such that }a\equiv x^2 \pmod{p},\\ -1\pmod{p}& \text{ if there is no such integer.} \end{cases} </math> Euler's criterion can be concisely reformulated using the Legendre symbol: :<math> \left(\frac{a}{p}\right) \equiv a^{\tfrac{p-1}{2}} \pmod p. </math> :<math>\left(\frac{a}{p}\right) = \begin{cases} 1 & \text{if } a \text{ is a quadratic residue modulo } p \text{ and } a \not\equiv 0\pmod p, \\ -1 & \text{if } a \text{ is a non-quadratic residue modulo } p, \\ 0 & \text{if } a \equiv 0 \pmod p. \end{cases}</math> It is known that <math>3</math> is a quadratic residue modulo <math>11.</math> Therefore <math>(3^5)\ %\ 11</math> should be <math>1.</math> <syntaxhighlight lang=python> # python code: >>> (3**5) % 11 1 </syntaxhighlight> It is known that <math>7</math> is a quadratic non-residue modulo <math>11.</math> Therefore <math>(7^5)\ %\ 11</math> should be <math>-1.</math> <syntaxhighlight lang=python> # python code: >>> (7**5) % 11 10 </syntaxhighlight> :<math>10 \equiv -1 \pmod{11}</math> Python's decimal module provides a method for computing <math>(a^x)\ %\ p</math> very efficiently for both small and very large numbers. <syntaxhighlight lang=python> # python code: >>> import decimal >>> decimal.Context().power(3,5,11) Decimal('1') >>> decimal.Context().power(7,5,11) Decimal('10') >>> >>> a = 3456789 >>> p = 761838257287 >>> decimal.Context().power(a, p>>1, p) Decimal('761838257286') </syntaxhighlight> :<math>761838257286 \equiv -1 \pmod{761838257287}</math> Value <math>a = 3456789</math> is not a quadratic residue modulo <math>p = 761838257287.</math> {{RoundBoxTop|theme=3}} An exact square such as <math>1,4,9,16,25,\dots</math> is always a quadratic residue modulo an odd prime <math>p.</math> {{RoundBoxBottom}} ===Product of 2 residues=== Let <math>a,b</math> be quadratic residues modulo odd prime <math>p.</math> Let <math>q = \frac{p-1}{2}.</math> Then: <math>a^q \equiv 1 \pmod p</math> <math>b^q \equiv 1 \pmod p</math> By law of multiplication: <math>(a^q)(b^q) \equiv (1)(1) \pmod p</math> or <math>(a\cdot b)^q \equiv 1 \pmod p</math> Product <math>(a\cdot b)</math> of 2 quadratic residues <math>a, b</math> is quadratic residue. Similarly, product of 2 non-residues is residue, and product of residue and non-residue is non-residue. ==Factors of integer N== Several modern methods for determining the factors of a given integer attempt to create two congruent squares modulo integer <math>N.</math> <math>x^2 \equiv y^2 \pmod{N}</math> This means that the difference between the two squares is exactly divisible by <math>N</math>: <math>N\mid (x^2 - y^2).</math> Integer <math>N</math> always contains the factors <math>N,1,</math> called trivial factors. If <math>N</math> contains two non-trivial factors <math>p,q,</math> then: <math>\frac{(x+y)(x-y)}{p \cdot q}.</math> With a little luck <math>p\mid (x+y)</math> and <math>q\mid (x-y)</math> in which case: <math>p = \text{igcd}(x+y, N)</math> and <math>q = \text{igcd}(x-y, N)</math> where "<math>\text{igcd}</math>" is function "<math>\text{integer greatest common divisor.}</math>" ===A simple example:=== We will use quadratic congruences to calculate factors of <math>N = 4171</math> for <math>164 \ge x \ge 1.</math> ====Right hand side exact square==== One congruence produced an exact square for y: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 70 | 4900 | 729 |} :<math>4900 \equiv 729 \pmod{N}</math> :<math>70^2 \equiv 27^2 \pmod{N}</math> <math>p = \text{igcd}(70-27, 4171)</math> <math>= \text{igcd}(43, 4171)</math> <math>= 43.</math> <math>q = \text{igcd}(70+27, 4171)</math> <math>= \text{igcd}(97, 4171)</math> <math>= 97.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> ====Right hand side negative==== Table below contains a sample of values of <math>x</math> that produce negative <math>y:</math> {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <math>\ \ </math><code>7</code>||<math>\ \ \ \ </math><code>49</code>||<code>-4122</code><math>\ \ \ \ \ \ </math> |- | <math>\ \ </math><code>8</code>||<math>\ \ \ \ </math><code>64</code>||<code>-4107</code><math>\ \ </math><code>**</code> |- | <math>\ \ </math><code>9</code>||<math>\ \ \ \ </math><code>81</code>||<code>-4090</code><math>\ \ \ \ \ \ </math> |- | <code>10</code>||<math>\ \ </math><code>100</code>||<code>-4071</code><math>\ \ \ \ \ \ </math> |- | <code>11</code>||<math>\ \ </math><code>121</code>||<code>-4050</code><math>\ \ </math><code>!!</code> |- | <code>12</code>||<math>\ \ </math><code>144</code>||<code>-4027</code><math>\ \ \ \ \ \ </math> |- | <code>60</code>||<code>3600</code>||<math>\ \ </math><code>-571</code><math>\ \ \ \ \ \ </math> |- | <code>61</code>||<code>3721</code>||<math>\ \ </math><code>-450</code><math>\ \ </math><code>!!</code> |- | <code>62</code>||<code>3844</code>||<math>\ \ </math><code>-327</code><math>\ \ \ \ \ \ </math> |- | <code>63</code>||<code>3969</code>||<math>\ \ </math><code>-220</code><math>\ \ \ \ \ \ </math> |- | <code>64</code>||<code>4096</code>||<math>\ \ \ \ </math><code>-75</code><math>\ \ </math><code>**</code> |} =====Non-trivial result 1===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 8 | 64 | -4107 ** |- | 64 | 4096 | -75 <math>\ \ \ \ </math>** |} :<math>64 \equiv -4107 \pmod{N}</math> :<math>4096 \equiv -75 \pmod{N}</math> :<math>64\cdot 4096 \equiv -4107\cdot (-75) \pmod{N}</math> :<math>262144 \equiv 308025 \pmod{N}</math> :<math>512^2 \equiv 555^2 \pmod{4171}</math> <math>p = \text{igcd}(555-512, 4171)</math> <math>= \text{igcd}(43, 4171)</math> <math>= 43.</math> <math>q = \text{igcd}(555+512, 4171)</math> <math>= \text{igcd}(1067, 4171)</math> <math>= 97.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> =====Non-trivial result 2===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <code>11</code> || <code></code><code>121</code> || <code>-4050</code><code>!!</code> |- | <code>61</code> || <code>3721</code> || <code></code><code>-450</code><code>!!</code> |} :<math>121 \equiv -4050 \pmod{N}</math> :<math>3721 \equiv -450 \pmod{N}</math> :<math>121\cdot 3721 \equiv -4050 \cdot (-450) \pmod{N}</math> :<math>450241 \equiv 1822500 \pmod{N}</math> :<math>671^2 \equiv 1350^2 \pmod{4171}</math> <math>p = \text{igcd}(1350-671, 4171)</math> <math>= \text{igcd}(679, 4171)</math> <math>= 97.</math> <math>q = \text{igcd}(1350+671, 4171)</math> <math>= \text{igcd}(2021, 4171)</math> <math>= 43.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> ====Right hand side positive==== Table below contains a sample of values of <math>x</math> that produce positive <math>y:</math> {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <math>\ \ </math><code>65</code>||<math>\ \ </math><code>4225</code>||<math>\ \ \ \ \ \ </math><code>54</code><math>\ \ </math><code>**</code><math>\ \ \ \ </math> |- | <math>\ \ </math><code>66</code>||<math>\ \ </math><code>4356</code>||<math>\ \ \ \ </math><code>185</code><math>\ \ \ \ \ \ \ \ \ \ </math> |- | <math>\ \ </math><code>88</code>||<math>\ \ </math><code>7744</code>||<math>\ \ </math><code>3573</code><math>\ \ \ \ \ \ \ \ \ \ </math> |- | <math>\ \ </math><code>89</code>||<math>\ \ </math><code>7921</code>||<math>\ \ </math><code>3750</code><math>\ \ </math><code>**!!</code> |- | <math>\ \ </math><code>90</code>||<math>\ \ </math><code>8100</code>||<math>\ \ </math><code>3929</code><math>\ \ \ \ \ \ \ \ \ \ </math> |- | <code>144</code>||<code>20736</code>||<code>16565</code><math>\ \ \ \ \ \ \ \ \ \ </math> |- | <code>145</code>||<code>21025</code>||<code>16854</code><math>\ \ \ \ \ \ </math><code>!!</code> |- | <code>146</code>||<code>21316</code>||<code>17145</code><math>\ \ \ \ \ \ \ \ \ \ </math> |} =====Non-trivial result===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <code>65</code>||<code>4225</code>||<math>\ \ \ \ </math><code>54</code><math>\ \ </math><code>**</code><math>\ \ \ \ </math> |- | <code>89</code>||<code>7921</code>||<code>3750</code><math>\ \ </math><code>**!!</code> |} :<math>4225 \equiv 54 \pmod{N}</math> :<math>7921 \equiv 3750 \pmod{N}</math> :<math>4225\cdot 7921 \equiv 54 \cdot 3750 \pmod{N}</math> :<math>33466225 \equiv 202500 \pmod{N}</math> :<math>5785^2 \equiv 450^2 \pmod{4171}</math> <math>p = \text{igcd}(5785-450, 4171)</math> <math>= \text{igcd}(5335, 4171)</math> <math>= 97.</math> <math>q = \text{igcd}(5785+450, 4171)</math> <math>= \text{igcd}(6235, 4171)</math> <math>= 43.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> =====Trivial result===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <math>\ \ </math><code>89</code>||<math>\ \ </math><code>7921</code>||<math>\ \ </math><code>3750</code><math>\ \ </math><code>**!!</code> |- | <code>145</code>||<code>21025</code>||<code>16854</code><math>\ \ \ \ \ \ </math><code>!!</code> |} :<math>7921 \equiv 3750 \pmod{N}</math> :<math>21025 \equiv 16854 \pmod{N}</math> :<math>7921\cdot 21025 \equiv 3750 \cdot 16854 \pmod{N}</math> :<math>166539025 \equiv 63202500 \pmod{N}</math> :<math>12905^2 \equiv 7950^2 \pmod{4171}</math> <math>p = \text{igcd}(12905-7950, 4171)</math> <math>= \text{igcd}(4955, 4171)</math> <math>= 1.</math> <math>q = \text{igcd}(12905+7950, 4171)</math> <math>= \text{igcd}(20855, 4171)</math> <math>= 4171.</math> This congruence produced the trivial factors of <math>4171.</math> ====With 3 congruences==== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <math>\ \ </math><code>56</code>||<math>\ \ </math><code>3136</code>||<code>-1035</code> |- | <math>\ \ </math><code>59</code>||<math>\ \ </math><code>3481</code>||<math>\ \ </math><code>-690</code> |- | <code>145</code>||<code>21025</code>||<code>16854</code> |} :<math>3136 \equiv -1035 \pmod{N}</math> :<math>3481 \equiv -690 \pmod{N}</math> :<math>21025 \equiv 16854 \pmod{N}</math> :<math>3136\cdot 3481 \cdot 21025 \equiv -1035 \cdot -690 \cdot 16854 \pmod{N}</math> :<math>229517646400 \equiv 12036284100 \pmod{N}</math> :<math>479080^2 \equiv 109710^2 \pmod{4171}</math> <math>p=\text{igcd}(479080-109710,4171)</math> <math>= 43.</math> <math>q = \text{igcd}(479080+109710, 4171)</math> <math>= 97.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> =Links to related topics= [https://en.wikipedia.org/wiki/Quadratic_residue Quadratic Residue] [https://en.wikipedia.org/wiki/Modular_arithmetic Modular Arithmetic] [https://en.wikipedia.org/wiki/Leonhard_Euler Leonhard Euler,] [https://en.wikipedia.org/wiki/Euler%27s_criterion Euler's Criterion] [https://en.wikipedia.org/wiki/Adrien-Marie_Legendre Adrien-Marie Legendre,] [https://en.wikipedia.org/wiki/Legendre_symbol Legendre Symbol] [https://en.wikipedia.org/wiki/Carl_Pomerance Carl Pomerance,] [https://en.wikipedia.org/wiki/Quadratic_sieve Quadratic sieve] [https://en.wikipedia.org/wiki/Greatest_common_divisor Greatest common divisor,] [https://en.wikipedia.org/wiki/Recursion_(computer_science)#Greatest_common_divisor Greatest common divisor (Example of Recursion)] [https://docs.python.org/3.4/library/decimal.html?highlight=decimal#decimal.Context.power Python's decimal Module] phemqm3vqgiqy0qzpqdw8om6tvoscex 2413957 2413956 2022-08-12T14:02:27Z ThaniosAkro 2805358 /* Non-trivial result 1 */ wikitext text/x-wiki =Congruences= The subject of congruences is a field of mathematics that covers the integers, their relationship to each other and also the effect of arithmetic operations on their relationship to each other. Expressed mathematically: :<math>A \equiv B \pmod{N}</math> read as: A is congruent with B modulo N. {{RoundBoxTop|theme=2}} <math>A,B,N</math> are integers and <math>N > 1.</math> {{RoundBoxBottom}} This means that: * A modulo N equals B modulo N, * the difference, A-B, is exactly divisible by N, or * <math>A-B = K\cdot N.</math> where p modulo N or <code>p % N</code> is the remainder when p is divided by N. For example: <math>23 \equiv 8 \pmod{5}</math> because division <math>\frac{23-8}{5}</math> is exact without remainder, or <math>5\mid (23-8).</math> Similarly, <math>39 \not\equiv 29 \,\pmod{7}</math> because division <math>\frac{39-29}{7}</math> is not exact, or <math>7\nmid (39-29).</math> ==Law of addition== ===Adding a constant=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N}, </math> then: <math>A+q \equiv B+q \pmod{N}.</math> Proof: <math>A-B = K\cdot N</math>, therefore <math>A = B + K\cdot N.</math> <math>(A+q) - (B+q) = B + K\cdot N + q - B - q = K\cdot N</math> which is exactly divisible by N. {{RoundBoxBottom}} ===Adding 2 congruences=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N}, </math> and <math>C \equiv D \pmod{N}, </math> then: <math>A+C \equiv B+D \pmod{N}.</math> Proof: <math>A-B = K_1\cdot N</math>, therefore <math>A = B + K_1\cdot N</math> and <math>C = D + K_2\cdot N</math> <math>(A+C) - (B+D)</math> <math>= B + K_1\cdot N + D + K_2\cdot N - B - D</math> <math>= N(K_1 + K_2)</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of Common Congruence== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> and <math>C \equiv B \pmod{N},</math> then: <math>A \equiv C \pmod{N}.</math> Proof: <math>A = B + K_1\cdot N</math> and <math>C = B + K_2\cdot N.</math> <math>A - C = B + K_1\cdot N - B - K_2\cdot N = (K_1 - K_2)N</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of Multiplication== ===by a constant=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> then: <math>A\cdot p \equiv B\cdot p \pmod{N}.</math> Proof: <math>A\cdot p - B\cdot p = p(A-B)</math> which is exactly divisible by N. {{RoundBoxBottom}} ===by another congruence=== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> and <math>C \equiv D \pmod{N},</math> then: <math>A\cdot C \equiv B\cdot D \pmod{N}.</math> Proof: <math>A = B + K_1\cdot N</math> and <math>C = D + K_2\cdot N.</math> <math>A\cdot C - B\cdot D</math> <math>= (B + K_1\cdot N)( D + K_2\cdot N) - B\cdot D</math> <math>= B\cdot D + B\cdot K_2\cdot N + K_1\cdot N\cdot D + K_1\cdot N\cdot K_2\cdot N - B\cdot D</math> <math>= N( B\cdot K_2 + K_1\cdot D + K_1\cdot K_2\cdot N )</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of squares== {{RoundBoxTop|theme=2}} If <math>A \equiv B \pmod{N} </math> then: <math>A^2 \equiv B^2 \pmod{N}.</math> Proof: <math>A^2 - B^2 = (A+B)(A-B)</math> which is exactly divisible by N. {{RoundBoxBottom}} ==Law of Division?== {{RoundBoxTop|theme=2}} A simple example shows that a "law of division" does not exist. <math>24 \equiv 14 \pmod{10}.</math> However <math>\frac{24}{2} \not\equiv \frac{14}{2} \pmod{10}</math> Because <math>12 - 7 = 5</math> is not exactly divisible by <math>10</math> {{RoundBoxBottom}} =Quadratic Congruences= A quadratic congruence is a congruence that contains at least one exact square, for example: <math>x^2 \equiv y \pmod{N}</math> or <math>x^2 \equiv y^2 \pmod{N}.</math> Initially, let us consider the congruence: <math>x^2 \equiv y \pmod{N}.</math> If <math>y = x^2 - N,</math> then: <math>x^2 \equiv y \pmod{N}.</math> Proof: <math>x^2 - y = x^2 - (x^2 - N) = N</math> which is exactly divisible by <math>N.</math> Consider an example with real numbers. Let <math>N = 257</math> and <math>26 \ge x \ge 6.</math> <syntaxhighlight> N = 257 </syntaxhighlight> {| class="wikitable" |- ! <math>x</math> !! <math>x^2 - N</math> |- | <code></code><code>6</code> || <code>-221</code> |- | <code></code><code>7</code> || <code>-208</code> |- | <code></code><code>8</code> || <code>-193</code> |- | <code></code><code>9</code> || <code>-176</code> |- | <code>10</code> || <code>-157</code> |- | <code>11</code> || <code>-136</code> |- | <code>12</code> || <code>-113</code> |- | <code>13</code> || <code></code><code>-88</code> |- | <code>14</code> || <code></code><code>-61</code> |- | <code>15</code> || <code></code><code>-32</code> |- | <code>16</code> || <code></code><code></code><code>-1</code> |- | <code>17</code> || <code></code><code></code><code>32</code> |- | <code>18</code> || <code></code><code></code><code>67</code> |- | <code>19</code> || <code></code><code>104</code> |- | <code>20</code> || <code></code><code>143</code> |- | <code>21</code> || <code></code><code>184</code> |- | <code>22</code> || <code></code><code>227</code> |- | <code>23</code> || <code></code><code>272</code> |- | <code>24</code> || <code></code><code>319</code> |- | <code>25</code> || <code></code><code>368</code> |- | <code>26</code> || <code></code><code>419</code> |} A cursory glance at the values of <math>x^2 - N</math> indicates that the value <math>x^2 - N</math> is never divisible by <math>5.</math> Proof: <math>N \equiv 2 \pmod{5}</math> therefore <math>N - 2 = k5</math> or <math>N = 5k + 2.</math> The table shows all possible values of <math>x\ %\ 5:</math> <syntaxhighlight> x | x^2 | y = x^2 - N ------ | --------------- | ----------------------------------------------- 5p + 0 | 25pp | 25pp - (5k+2) = 25pp - 5k - 2 5p + 1 | 25pp + 10p + 1 | 25pp + 10p + 1 - (5k+2) = 25pp + 10p - 5k - 1 5p + 2 | 25pp + 20p + 4 | 25pp + 20p + 4 - (5k+2) = 25pp + 20p - 5k + 2 5p + 3 | 25pp + 30p + 9 | 25pp + 30p + 9 - (5k+2) = 25pp + 30p - 5k + 7 5p + 4 | 25pp + 40p + 16 | 25pp + 40p + 16 - (5k+2) = 25pp + 40p - 5k + 14 </syntaxhighlight> As you can see, the value <math>y = x^2 - N</math> is never exactly divisible by <math>5.</math> If you look closely, you will see also that it is never exactly divisible by <math>3.</math> Why is this? An interesting question that leads us to the topic of quadratic residues. ==Quadratic Residues== Consider all the congruences for prime number <math>5:</math> <math>x^2 \equiv y \pmod{5}</math> for <math>5 > x \ge 0.</math> {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>(x^2)\ %\ 5</math> |- | <code>0</code> || <code></code><code>0</code> || <code>0</code> |- | <code>1</code> || <code></code><code>1</code> || <code>1</code> |- | <code>2</code> || <code></code><code>4</code> || <code>4</code> |- | <code>3</code> || <code></code><code>9</code> || <code>4</code> |- | <code>4</code> || <code>16</code> || <code>1</code> |} Quadratic residues of <math>5</math> are <math>0,1,4.</math> Values <math>2,3</math> are not quadratic residues of <math>5.</math> These values are quadratic non-residues. To calculate the quadratic residues of a small prime <math>p:</math> <syntaxhighlight lang=python> # python code: def quadResidues(p) : L1 = [] for v in range (p>>1, -1, -1) : L1 += [(v*v) % p] return L1 print (quadResidues(11)) </syntaxhighlight> <syntaxhighlight> [3, 5, 9, 4, 1, 0] </syntaxhighlight> Quadratic residues of <math>11</math> are <math>0,1,3,4,5,9.</math> The method presented here answers the question, "What are the quadratic residues of p?" If <math>p</math> is a very large prime, the question is often, "Is r a quadratic residue of p?" The answer is found in advanced number theory. Let us return to quadratic residues mod <math>N = 257.</math> <math>N\ %\ 5 = 2,</math> therefore <math>N</math> is not a quadratic residue of <math>5.</math> This is why <math>x^2 - N</math> is never divisible by <math>5</math> exactly. <math>N\ %\ 11 = 4,</math> therefore <math>N</math> is a quadratic residue of <math>11</math> and a value of <math>x</math> that satisfies the congruence <math>x^2 \equiv 4 \pmod{257}</math> has form <math>11p \pm 2.</math> From the table above: <syntaxhighlight> N = 257 </syntaxhighlight> {| class="wikitable" |- ! <math>x</math> !! <math>x^2\ -\ N</math> |- | <code></code><code>9</code> || <code>-176</code> |- | <code>13</code> || <code></code><code>-88</code> |- | <code>20</code> || <code></code><code>143</code> |- | <code>24</code> || <code></code><code>319</code> |} These <math>4</math> values of <math>x^2 - N</math> are exactly divisible by <math>11.</math> <math>x = 9</math> is <math>11\cdot 1 - 2.</math> <math>x = 13</math> is <math>11\cdot 1 + 2.</math> <math>x = 20</math> is <math>11\cdot 2 - 2.</math> <math>x = 24</math> is <math>11\cdot 2 + 2.</math> ===Products=== This section uses prime number <math>41</math> as an example. Using <code>quadResidues(p)</code> quadratic residues of <math>41</math> are: <syntaxhighlight> qr41 = [0, 1, 2, 4, 5, 8, 9, 10, 16, 18, 20, 21, 23, 25, 31, 32, 33, 36, 37, 39, 40] </syntaxhighlight> Quadratic non-residues of <math>41</math> are: <syntaxhighlight> qnr41 = [3, 6, 7, 11, 12, 13, 14, 15, 17, 19, 22, 24, 26, 27, 28, 29, 30, 34, 35, 38] </syntaxhighlight> ====of 2 residues==== A simple test to verify that the product of 2 residues is a residue: <syntaxhighlight lang=python> # Python code. for index1 in range (0, len(qr41)) : v1 = qr41[index1] for index2 in range (index1, len(qr41)) : v2 = qr41[index2] residue = (v1*v2) % 41 if residue not in qr41 : print ('residue',residue,'not quadratic.') </syntaxhighlight> This test shows that, at least for prime number <math>41,</math> the product of 2 residues is a residue. Advanced math proves that this is true for all primes. ====of 2 non-residues==== A simple test to verify that the product of 2 non-residues is a residue: <syntaxhighlight lang=python> # Python code. for index1 in range (0, len(qnr41)) : v1 = qnr41[index1] for index2 in range (index1, len(qnr41)) : v2 = qnr41[index2] residue = (v1*v2) % 41 if residue not in qr41 : print ('residue',residue,'not quadratic.') </syntaxhighlight> This test shows that, at least for prime number <math>41,</math> the product of 2 non-residues is a residue. Advanced math proves that this is true for all primes. ====of residue and non-residue==== A simple test to verify that the product of residue and non-residue is non-residue: <syntaxhighlight lang=python> # Python code. for index1 in range (1, len(qr41)) : v1 = qr41[index1] for index2 in range (0, len(qnr41)) : v2 = qnr41[index2] residue = (v1*v2) % 41 if residue not in qnr41 : print ('residue',residue,'quadratic.') </syntaxhighlight> This test shows that, at least for prime number <math>41,</math> the product of residue and non-residue is non-residue. Advanced math proves that this is true for all primes. {{RoundBoxTop|theme=2}} Some authors may consider <math>0</math> as not a legitimate residue. <math>0</math> is not included as a residue in the test above. {{RoundBoxBottom}} ==Euler's criterion== In number theory, '''Euler's criterion''' is a formula for determining whether or not an integer is a quadratic residue modulo a prime number. Precisely, Let ''p'' be an odd prime and ''a'' be an integer coprime to ''p''. Then :<math> a^{\tfrac{p-1}{2}} \equiv \begin{cases} \;\;\,1\pmod{p}& \text{ if there is an integer }x \text{ such that }a\equiv x^2 \pmod{p},\\ -1\pmod{p}& \text{ if there is no such integer.} \end{cases} </math> Euler's criterion can be concisely reformulated using the Legendre symbol: :<math> \left(\frac{a}{p}\right) \equiv a^{\tfrac{p-1}{2}} \pmod p. </math> :<math>\left(\frac{a}{p}\right) = \begin{cases} 1 & \text{if } a \text{ is a quadratic residue modulo } p \text{ and } a \not\equiv 0\pmod p, \\ -1 & \text{if } a \text{ is a non-quadratic residue modulo } p, \\ 0 & \text{if } a \equiv 0 \pmod p. \end{cases}</math> It is known that <math>3</math> is a quadratic residue modulo <math>11.</math> Therefore <math>(3^5)\ %\ 11</math> should be <math>1.</math> <syntaxhighlight lang=python> # python code: >>> (3**5) % 11 1 </syntaxhighlight> It is known that <math>7</math> is a quadratic non-residue modulo <math>11.</math> Therefore <math>(7^5)\ %\ 11</math> should be <math>-1.</math> <syntaxhighlight lang=python> # python code: >>> (7**5) % 11 10 </syntaxhighlight> :<math>10 \equiv -1 \pmod{11}</math> Python's decimal module provides a method for computing <math>(a^x)\ %\ p</math> very efficiently for both small and very large numbers. <syntaxhighlight lang=python> # python code: >>> import decimal >>> decimal.Context().power(3,5,11) Decimal('1') >>> decimal.Context().power(7,5,11) Decimal('10') >>> >>> a = 3456789 >>> p = 761838257287 >>> decimal.Context().power(a, p>>1, p) Decimal('761838257286') </syntaxhighlight> :<math>761838257286 \equiv -1 \pmod{761838257287}</math> Value <math>a = 3456789</math> is not a quadratic residue modulo <math>p = 761838257287.</math> {{RoundBoxTop|theme=3}} An exact square such as <math>1,4,9,16,25,\dots</math> is always a quadratic residue modulo an odd prime <math>p.</math> {{RoundBoxBottom}} ===Product of 2 residues=== Let <math>a,b</math> be quadratic residues modulo odd prime <math>p.</math> Let <math>q = \frac{p-1}{2}.</math> Then: <math>a^q \equiv 1 \pmod p</math> <math>b^q \equiv 1 \pmod p</math> By law of multiplication: <math>(a^q)(b^q) \equiv (1)(1) \pmod p</math> or <math>(a\cdot b)^q \equiv 1 \pmod p</math> Product <math>(a\cdot b)</math> of 2 quadratic residues <math>a, b</math> is quadratic residue. Similarly, product of 2 non-residues is residue, and product of residue and non-residue is non-residue. ==Factors of integer N== Several modern methods for determining the factors of a given integer attempt to create two congruent squares modulo integer <math>N.</math> <math>x^2 \equiv y^2 \pmod{N}</math> This means that the difference between the two squares is exactly divisible by <math>N</math>: <math>N\mid (x^2 - y^2).</math> Integer <math>N</math> always contains the factors <math>N,1,</math> called trivial factors. If <math>N</math> contains two non-trivial factors <math>p,q,</math> then: <math>\frac{(x+y)(x-y)}{p \cdot q}.</math> With a little luck <math>p\mid (x+y)</math> and <math>q\mid (x-y)</math> in which case: <math>p = \text{igcd}(x+y, N)</math> and <math>q = \text{igcd}(x-y, N)</math> where "<math>\text{igcd}</math>" is function "<math>\text{integer greatest common divisor.}</math>" ===A simple example:=== We will use quadratic congruences to calculate factors of <math>N = 4171</math> for <math>164 \ge x \ge 1.</math> ====Right hand side exact square==== One congruence produced an exact square for y: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | 70 | 4900 | 729 |} :<math>4900 \equiv 729 \pmod{N}</math> :<math>70^2 \equiv 27^2 \pmod{N}</math> <math>p = \text{igcd}(70-27, 4171)</math> <math>= \text{igcd}(43, 4171)</math> <math>= 43.</math> <math>q = \text{igcd}(70+27, 4171)</math> <math>= \text{igcd}(97, 4171)</math> <math>= 97.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> ====Right hand side negative==== Table below contains a sample of values of <math>x</math> that produce negative <math>y:</math> {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <math>\ \ </math><code>7</code>||<math>\ \ \ \ </math><code>49</code>||<code>-4122</code><math>\ \ \ \ \ \ </math> |- | <math>\ \ </math><code>8</code>||<math>\ \ \ \ </math><code>64</code>||<code>-4107</code><math>\ \ </math><code>**</code> |- | <math>\ \ </math><code>9</code>||<math>\ \ \ \ </math><code>81</code>||<code>-4090</code><math>\ \ \ \ \ \ </math> |- | <code>10</code>||<math>\ \ </math><code>100</code>||<code>-4071</code><math>\ \ \ \ \ \ </math> |- | <code>11</code>||<math>\ \ </math><code>121</code>||<code>-4050</code><math>\ \ </math><code>!!</code> |- | <code>12</code>||<math>\ \ </math><code>144</code>||<code>-4027</code><math>\ \ \ \ \ \ </math> |- | <code>60</code>||<code>3600</code>||<math>\ \ </math><code>-571</code><math>\ \ \ \ \ \ </math> |- | <code>61</code>||<code>3721</code>||<math>\ \ </math><code>-450</code><math>\ \ </math><code>!!</code> |- | <code>62</code>||<code>3844</code>||<math>\ \ </math><code>-327</code><math>\ \ \ \ \ \ </math> |- | <code>63</code>||<code>3969</code>||<math>\ \ </math><code>-220</code><math>\ \ \ \ \ \ </math> |- | <code>64</code>||<code>4096</code>||<math>\ \ \ \ </math><code>-75</code><math>\ \ </math><code>**</code> |} =====Non-trivial result 1===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <math>\ \ </math><code>8</code>||<math>\ \ \ \ </math><code>64</code>||<code>-4107</code><math>\ \ </math><code>**</code> |- | <code>64</code>||<code>4096</code>||<math>\ \ \ \ </math><code>-75</code><math>\ \ </math><code>**</code> |} :<math>64 \equiv -4107 \pmod{N}</math> :<math>4096 \equiv -75 \pmod{N}</math> :<math>64\cdot 4096 \equiv -4107\cdot (-75) \pmod{N}</math> :<math>262144 \equiv 308025 \pmod{N}</math> :<math>512^2 \equiv 555^2 \pmod{4171}</math> <math>p = \text{igcd}(555-512, 4171)</math> <math>= \text{igcd}(43, 4171)</math> <math>= 43.</math> <math>q = \text{igcd}(555+512, 4171)</math> <math>= \text{igcd}(1067, 4171)</math> <math>= 97.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> =====Non-trivial result 2===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <code>11</code> || <code></code><code>121</code> || <code>-4050</code><code>!!</code> |- | <code>61</code> || <code>3721</code> || <code></code><code>-450</code><code>!!</code> |} :<math>121 \equiv -4050 \pmod{N}</math> :<math>3721 \equiv -450 \pmod{N}</math> :<math>121\cdot 3721 \equiv -4050 \cdot (-450) \pmod{N}</math> :<math>450241 \equiv 1822500 \pmod{N}</math> :<math>671^2 \equiv 1350^2 \pmod{4171}</math> <math>p = \text{igcd}(1350-671, 4171)</math> <math>= \text{igcd}(679, 4171)</math> <math>= 97.</math> <math>q = \text{igcd}(1350+671, 4171)</math> <math>= \text{igcd}(2021, 4171)</math> <math>= 43.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> ====Right hand side positive==== Table below contains a sample of values of <math>x</math> that produce positive <math>y:</math> {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <math>\ \ </math><code>65</code>||<math>\ \ </math><code>4225</code>||<math>\ \ \ \ \ \ </math><code>54</code><math>\ \ </math><code>**</code><math>\ \ \ \ </math> |- | <math>\ \ </math><code>66</code>||<math>\ \ </math><code>4356</code>||<math>\ \ \ \ </math><code>185</code><math>\ \ \ \ \ \ \ \ \ \ </math> |- | <math>\ \ </math><code>88</code>||<math>\ \ </math><code>7744</code>||<math>\ \ </math><code>3573</code><math>\ \ \ \ \ \ \ \ \ \ </math> |- | <math>\ \ </math><code>89</code>||<math>\ \ </math><code>7921</code>||<math>\ \ </math><code>3750</code><math>\ \ </math><code>**!!</code> |- | <math>\ \ </math><code>90</code>||<math>\ \ </math><code>8100</code>||<math>\ \ </math><code>3929</code><math>\ \ \ \ \ \ \ \ \ \ </math> |- | <code>144</code>||<code>20736</code>||<code>16565</code><math>\ \ \ \ \ \ \ \ \ \ </math> |- | <code>145</code>||<code>21025</code>||<code>16854</code><math>\ \ \ \ \ \ </math><code>!!</code> |- | <code>146</code>||<code>21316</code>||<code>17145</code><math>\ \ \ \ \ \ \ \ \ \ </math> |} =====Non-trivial result===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <code>65</code>||<code>4225</code>||<math>\ \ \ \ </math><code>54</code><math>\ \ </math><code>**</code><math>\ \ \ \ </math> |- | <code>89</code>||<code>7921</code>||<code>3750</code><math>\ \ </math><code>**!!</code> |} :<math>4225 \equiv 54 \pmod{N}</math> :<math>7921 \equiv 3750 \pmod{N}</math> :<math>4225\cdot 7921 \equiv 54 \cdot 3750 \pmod{N}</math> :<math>33466225 \equiv 202500 \pmod{N}</math> :<math>5785^2 \equiv 450^2 \pmod{4171}</math> <math>p = \text{igcd}(5785-450, 4171)</math> <math>= \text{igcd}(5335, 4171)</math> <math>= 97.</math> <math>q = \text{igcd}(5785+450, 4171)</math> <math>= \text{igcd}(6235, 4171)</math> <math>= 43.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> =====Trivial result===== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <math>\ \ </math><code>89</code>||<math>\ \ </math><code>7921</code>||<math>\ \ </math><code>3750</code><math>\ \ </math><code>**!!</code> |- | <code>145</code>||<code>21025</code>||<code>16854</code><math>\ \ \ \ \ \ </math><code>!!</code> |} :<math>7921 \equiv 3750 \pmod{N}</math> :<math>21025 \equiv 16854 \pmod{N}</math> :<math>7921\cdot 21025 \equiv 3750 \cdot 16854 \pmod{N}</math> :<math>166539025 \equiv 63202500 \pmod{N}</math> :<math>12905^2 \equiv 7950^2 \pmod{4171}</math> <math>p = \text{igcd}(12905-7950, 4171)</math> <math>= \text{igcd}(4955, 4171)</math> <math>= 1.</math> <math>q = \text{igcd}(12905+7950, 4171)</math> <math>= \text{igcd}(20855, 4171)</math> <math>= 4171.</math> This congruence produced the trivial factors of <math>4171.</math> ====With 3 congruences==== The congruences: {| class="wikitable" |- ! <math>x</math> !! <math>x^2</math> !! <math>y = x^2 - N</math> |- | <math>\ \ </math><code>56</code>||<math>\ \ </math><code>3136</code>||<code>-1035</code> |- | <math>\ \ </math><code>59</code>||<math>\ \ </math><code>3481</code>||<math>\ \ </math><code>-690</code> |- | <code>145</code>||<code>21025</code>||<code>16854</code> |} :<math>3136 \equiv -1035 \pmod{N}</math> :<math>3481 \equiv -690 \pmod{N}</math> :<math>21025 \equiv 16854 \pmod{N}</math> :<math>3136\cdot 3481 \cdot 21025 \equiv -1035 \cdot -690 \cdot 16854 \pmod{N}</math> :<math>229517646400 \equiv 12036284100 \pmod{N}</math> :<math>479080^2 \equiv 109710^2 \pmod{4171}</math> <math>p=\text{igcd}(479080-109710,4171)</math> <math>= 43.</math> <math>q = \text{igcd}(479080+109710, 4171)</math> <math>= 97.</math> Non-trivial factors of <math>4171</math> are <math>43,97.</math> =Links to related topics= [https://en.wikipedia.org/wiki/Quadratic_residue Quadratic Residue] [https://en.wikipedia.org/wiki/Modular_arithmetic Modular Arithmetic] [https://en.wikipedia.org/wiki/Leonhard_Euler Leonhard Euler,] [https://en.wikipedia.org/wiki/Euler%27s_criterion Euler's Criterion] [https://en.wikipedia.org/wiki/Adrien-Marie_Legendre Adrien-Marie Legendre,] [https://en.wikipedia.org/wiki/Legendre_symbol Legendre Symbol] [https://en.wikipedia.org/wiki/Carl_Pomerance Carl Pomerance,] [https://en.wikipedia.org/wiki/Quadratic_sieve Quadratic sieve] [https://en.wikipedia.org/wiki/Greatest_common_divisor Greatest common divisor,] [https://en.wikipedia.org/wiki/Recursion_(computer_science)#Greatest_common_divisor Greatest common divisor (Example of Recursion)] [https://docs.python.org/3.4/library/decimal.html?highlight=decimal#decimal.Context.power Python's decimal Module] oj5iwuptzvv22t7q433ais3jb4rf7bp 0 285927 2414061 2413330 2022-08-13T09:03:57Z Icantchooseone 2947542 overview detail wikitext text/x-wiki {{title|Fear<br>What is fear, what causes it, and how can it be managed?}} {{MECR3|1=https://yourlinkgoeshere.com}} __TOC__ ==Overview== * definition of fear (fundamental life task: threat or danger present) ** expression of fear (facial expression, heart rate, sweat level) ** types of fear ** coping function (protect, avoid) * outline the similarities and differences between fear and anxiety * outline the cause of fear (psychologically, biologically and socially * strategies to manage fear (in and out of clinical setting) {{RoundBoxTop|theme=3}} '''Focus questions:''' * What is the first focus question? * What is the second focus question? * What is the third focus question? {{RoundBoxBottom}} {{tip| Suggestions for this section: * What is the problem? Why is it important? * How can specific motivation and/or emotion theories and research help? * Provide an example or case study. * Conclude with Focus questions to guide the chapter. }} == What is fear? == How you are going to structure the chapter? Aim for three to six main headings between the [[#Overview|Overview]] and [[#Conclusion|Conclusion]]. {{tip|Suggestions for this section: * For the [[Motivation and emotion/Assessment/Topic|topic development]], provide at least 3 bullet-points about key content per section. Include key citations. * For the [[Motivation and emotion/Assessment/Chapter|book chapter]], expand the bullet points into paragraphs. * If a section has a lot of content, arrange it into two to five sub-headings such as in the [[#Interactive learning features|interactive learning features section]]. Avoid having sections with only one sub-heading. }} == The difference between fear and anxiety == What brings an online book chapter to life are its interactive learning features. Case studies, feature boxes, figures, links, tables, and quiz questions can be used throughout the chapter. == What causes fear? == Case studies describe real-world examples of concepts in action. Case studies can be real or fictional. A case could be used multiple times during a chapter to illustrate different theories or stages. It is often helpful to present case studies using [[#Feature boxes|feature boxes]]. === Psychological perspective === Boxes can be used to highlight content, but don't overuse them. There are many different ways of creating boxes (e.g., see [[Help:Pretty boxes|Pretty boxes]]). Possible uses include: * Focus questions * Case studies or examples * Quiz questions * Take-home messages {{RoundBoxTop|theme=3}} ;Feature box example * Shaded background * Coloured border {{RoundBoxBottom}} === Biological perspective === [[File:Monkey-typing.jpg|right|205px|thumb|''Figure 1''. Example image with descriptive caption.]] Use figures to illustrate concepts, add interest, and provide examples. Figures can be used to show photographs, drawings, diagrams, graphs, etcetera. Figures can be embedded throughout the chapter, starting with the Overview section. Figures should be captioned (using a number and a description) in order to explain their relevance to the text. Possible images can be found at [[commons:|Wikimedia Commons]]. Images can also be uploaded if they are licensed for re-use or if you created the image. Each figure should be referred to at least once in the main text (e.g., see Figure 1). ===Social perspective=== Where key words are first used, make them into [[Help:Links|interwiki links]] such as Wikipedia links to articles about famous people (e.g., [[w:Sigmund Freud|Sigmund Freud]] and key concepts (e.g., [[w:Dreams|dreams]]) and links to book chapters about related topics (e.g., would you like to learn about how to overcome [[Motivation and emotion/Book/2020/Writer's block|writer's block]]?). == When does fear become a phobia? == Tables can be an effective way to organise and summarise information. Tables should be captioned (using APA style) to explain their relevance to the text. Plus each table should be referred to at least once in the main text (e.g., see Table 1 and Table 2). Here are some [[Motivation and emotion/Wikiversity/Tables|example 3 x 3 tables]] which could be adapted. == How can fear be managed? == Quizzes are a direct way to engage readers. But don't make quizzes too hard or long. It is better to have one or two review questions per major section than a long quiz at the end. Try to quiz conceptual understanding, rather than trivia. Here are some simple quiz questions which could be adapted. Choose the correct answers and click "Submit": === Within everyday life === ==== Mindfulness ==== ==== Self-control instruction ==== === Within clinical settings === ==== Cognitive behavioural therapy ==== ==== Exposure therapy ==== To learn about different types of quiz questions, see [[Help:Quiz|Quiz]]. ==Conclusion== == Recap quizzes == <quiz display="simple"> {Fear induce risk taking behaviour |type="()"} + True - False {Long quizzes are a good idea: |type="()"} - True + False </quiz>The Conclusion is arguably the most important section. It should be possible for someone to read the [[#Overview|Overview]] and the Conclusion and still get a good idea of the topic. {{tip|Suggestions for this section: * What is the answer to the question in the sub-title (based on psychological theory and research)? * What are the answers to the focus questions? * What are the practical, take-home messages? }} ==See also== Provide up to half-a-dozen [[Help:Contents/Links#Interwiki_links|internal (wiki) links]] to relevant Wikiversity pages (esp. related [[Motivation and emotion/Book|motivation and emotion book chapters]]) and [[w:|Wikipedia articles]]. For example: * [[Motivation and emotion/Book/2016/Anorexia nervosa and extrinsic motivation|Anorexia nervosa and extrinsic motivation]] (Book chapter, 2016) * [[w:David McClelland|David McClelland]] (Wikipedia) * [[Motivation and emotion/Book/2018/Loss aversion|Loss aversion]] (Book chapter, 2018) * [[w:Maslow's hierarchy of needs|Maslow's hierarchy of needs]] (Wikipedia) {{tip|Suggestions for this section: * Present in alphabetical order. * Include the source in parentheses. }} ==References== List the cited references in [[w:APA style|APA style]] (7th ed.) or [[w:Wikipedia:Citing sources|wiki style]]. APA style example: {{Hanging indent|1= Blair, R. J. R. (2004). The roles of orbital frontal cortex in the modulation of antisocial behavior. ''Brain and Cognition'', ''55''(1), 198–208. https://doi.org/10.1016/S0278-2626(03)00276-8 Buckholtz, J. W., & Meyer-Lindenberg, A. (2008). MAOA and the neurogenetic architecture of human aggression. ''Trends in Neurosciences'', ''31''(3), 120–129. https://doi.org/10.1016/j.tins.2007.12.006 Eckardt, M., File, S., Gessa, G., Grant, K., Guerri, C., Hoffman, P., & Tabakoff, B. (1998). Effects of moderate alcohol consumption on the central nervous system. ''Alcoholism, Clinical and Experimental Research'', ''22''(5), 998–1040. https://doi.org/10.1111/j.1530-0277.1998.tb03695.x }} {{tip|Suggestions for this section: * Important aspects for APA style include: ** Wrap the set of references in the hanging indent template. Using "Edit source": <nowiki>{{Hanging indent|1= the full list of references}}</nowiki> ** Author surname, followed by a comma, then author initials separated by full stops and spaces ** Year of publication in parentheses ** Title of work in lower case except first letter and proper names, ending in a full-stop. ** Journal title in italics, volume number in italics, issue number in parentheses, first and last page numbers separated by an en-dash(–), followed by a full-stop. ** Provide the full doi as a URL and working hyperlink * Common mistakes include: ** incorrect capitalisation ** incorrect italicisation ** providing a "retrieved from" date (not part of APA 7th ed. style). ** citing sources that weren't actually read or consulted }} ==External links== Provide up to half-a-dozen [[Help:Contents/Links#External_links|external links]] to relevant resources such as presentations, news articles, and professional sites. For example: * [https://students.unimelb.edu.au/academic-skills/explore-our-resources/essay-writing/six-top-tips-for-writing-a-great-essay Six top tips for writing a great essay] (University of Melbourne) * [http://www.skillsyouneed.com/write/structure.html The importance of structure] (skillsyouneed.com) {{tip|Suggestions for this section: * Only select links to major external resources about the topic * Present in alphabetical order * Include the source in parentheses after the link }} [[Category:{{#titleparts:{{PAGENAME}}|3}}]] [[Category:Motivation and emotion/Book/Fear]] n2w77wvv553jmf3aesggj623xdajwdu 0 286028 2414030 2413778 2022-08-13T06:16:48Z Guy vandegrift 813252 /* Making one beat: N a large number */ wikitext text/x-wiki [[Image:Beating Frequency.svg|thumb|300px|Diagram of beat frequency]] A '''beat''' is an [[w:Interference (wave propagation)|interference]] pattern between two [[w:sound|sounds]] of slightly different [[w:frequency|frequencies]], ''perceived'' as a periodic variation in [[w:amplitude (music)|volume]] whose rate is the [[w:Difference (mathematics)|difference]] of the two frequencies. The fundamentals of this topic are taught at some level in virtually every introductory high school or college course. [[w:Beat (acoustics)|Wikipedia]] features the figure shown and equations like, :<math> f_\text{beat} = f_2 - f_1 = \frac{1}{\tau_b} = \frac{\left|\omega_2-\omega_1\right|}{2\pi}</math> But topics beyond these fundamentals are rarely pursued, and for good reason. Much about how humans perceive beats in musical intervals is poorly understood. This Wikiversity resource is not so much aimed at answering difficult questions, but to offer students the the opportunity to [https://www.pinterest.com/pin/164662930098107644/ "mess around"] in a way that enhances one's understanding of mathematics and computer programming. ===beats-angular frequency: Algebra=== Simple case (unison):<math>T_\text{simple}^{-1}=(2\pi)^{-1}(\omega_2-\omega_1) \implies</math> <math>2\pi / T_b = \left|\omega_2-\omega_1\right|</math> Define interval ratio, <math>1<p/q<2</math>, where: <math>\omega_p=p\omega_0</math> and <math>\omega_q=q\omega_0</math> The the lowest common harmonic of <math>\omega_p</math> and <math>\omega_q</math> is <math>\omega_h=pq\omega_0</math> Replace <math>p\to p+\Delta p </math> and <math>q\to q+\Delta q </math> <math>2\pi / T_b = \left| (p+\Delta p)q\omega_0 - p(q+\Delta q)\omega_0 \right| = \left|p\Delta\omega_q - q\Delta\omega_p\right|</math> <math>f_b=\left|\frac{p\Delta\omega_q - q\Delta\omega_p}{2\pi}\right|= \left| p\Delta f_q - q\Delta f_p\right|</math> Use <math>q\omega_p=p\omega_q \equiv qf_p=pf_q \equiv pT_p = qT_q</math> where <math>T=1/f</math> denotes period. Note that <math>\frac{\Delta f}{f}=-\frac{\Delta T}{T}\implies \Delta f = -\frac{\Delta T}{T^2}</math> <math>\frac{1}{T_b}=\left| \frac{q\Delta T_p}{T_p^2} - \frac{p\Delta T_q}{T_q^2} \right|= \left| \frac{p\Delta T_p-q\Delta T_q}{T_pT_q}\right|</math> ====Making one beat: N a large number==== Recalling that <math>p>q</math>, we now select a large number <math>N</math> and define a new period <math>\widetilde T_p</math> <math>NpT_p=NqT_q=(N-1)p\widetilde T_p \equiv T_c</math>. We will show that <math>T_c=T_b</math> <math>\Delta T_p = \widetilde T_p-T_p = \frac 1 N T_p</math> implies <math>N=\frac{T_p}{\Delta T_p}</math> where <math>\widetilde T_p=T_p+\Delta T_p</math>. What we have done: We slightly increased the period of the p wave in order to remove one cycle. Thus causes the new p wave to cycle through all phase differences. Define <math>T_c</math> to be the cycle time. Now find a formula: <math>NpT_p= T_c = \frac{T_p}{\Delta T_p}pT_p</math> implies <math>\frac 1 T_c =\frac{\Delta T_p}{T_p^2}\frac 1 p</math> f_c= \frac{-f_p}{p} \frac{\Delta f_p}{f_p} ==Fourier analysis== ''See also'' [[w:Kramers–Kronig relations]], [[w:Cauchy principal value]], [https://wiki.seg.org/wiki/Dictionary:Hilbert_transform]and [[w:Sokhotski–Plemelj theorem]] <math> \int_\infty^\infty e^{i\omega t}d\omega=2\pi\delta(t)</math> <math>\frac{1}{X+i\epsilon} = \frac {X}{X^2+ \epsilon^2} - i \pi \delta(X)</math> <math>\frac{1}{X+i\epsilon} = \frac {X}{X^2+ \epsilon^2} - \frac {i\epsilon}{X^2+ \epsilon^2}</math> <math>\frac 1 X = \text{pp} \frac 1 X -i\pi \delta(X)</math> ==Links== '''Basic''' * <u>[[Wikipedia:Beat (acoustics)]]</u>: The fact that Wikipedia only covers the basic ideas supports my contention that material beyond these well known topics will always be murky.<ref>{{cite journal |last= Weinberger |first= Norman |date= September 2006 |title= Music And The Brain |url= https://www.scientificamerican.com/article/music-and-the-brain-2006-09/ |journal= Scientific American |volume= 16 |issue= 3 |pages= 36-43 |doi= 10.1038/scientificamerican0906-36sp |accessdate=2022-08-04 }}</ref><ref>Note the inserted footnote templates regarding "verification" and "original research?" at [[w:special:permalink/1102305761]]. </ref> * <u>[http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/beat.html Hyperphysics: Sound/beat:]</u> parallels the Wikipedia article. * [https://www.omnicalculator.com/physics/beat-frequency <u>Omnicalculator's beat frequency demonstration</u>] effectively how the 3:2 rhythm pattern is just an ultra slow version of the consonant perfect fifth in music. '''Advanced (or otherwise different)''' * <u>[https://www.violinist.com/discussion/archive/18551/ Violinist.com]</u> discussion on using beats to tune a violin ==Footnotes== 5tt6dg2leek08e5pcqii22mg5k88574 2414031 2414030 2022-08-13T06:17:19Z Guy vandegrift 813252 /* Making one beat: N a large number */ wikitext text/x-wiki [[Image:Beating Frequency.svg|thumb|300px|Diagram of beat frequency]] A '''beat''' is an [[w:Interference (wave propagation)|interference]] pattern between two [[w:sound|sounds]] of slightly different [[w:frequency|frequencies]], ''perceived'' as a periodic variation in [[w:amplitude (music)|volume]] whose rate is the [[w:Difference (mathematics)|difference]] of the two frequencies. The fundamentals of this topic are taught at some level in virtually every introductory high school or college course. [[w:Beat (acoustics)|Wikipedia]] features the figure shown and equations like, :<math> f_\text{beat} = f_2 - f_1 = \frac{1}{\tau_b} = \frac{\left|\omega_2-\omega_1\right|}{2\pi}</math> But topics beyond these fundamentals are rarely pursued, and for good reason. Much about how humans perceive beats in musical intervals is poorly understood. This Wikiversity resource is not so much aimed at answering difficult questions, but to offer students the the opportunity to [https://www.pinterest.com/pin/164662930098107644/ "mess around"] in a way that enhances one's understanding of mathematics and computer programming. ===beats-angular frequency: Algebra=== Simple case (unison):<math>T_\text{simple}^{-1}=(2\pi)^{-1}(\omega_2-\omega_1) \implies</math> <math>2\pi / T_b = \left|\omega_2-\omega_1\right|</math> Define interval ratio, <math>1<p/q<2</math>, where: <math>\omega_p=p\omega_0</math> and <math>\omega_q=q\omega_0</math> The the lowest common harmonic of <math>\omega_p</math> and <math>\omega_q</math> is <math>\omega_h=pq\omega_0</math> Replace <math>p\to p+\Delta p </math> and <math>q\to q+\Delta q </math> <math>2\pi / T_b = \left| (p+\Delta p)q\omega_0 - p(q+\Delta q)\omega_0 \right| = \left|p\Delta\omega_q - q\Delta\omega_p\right|</math> <math>f_b=\left|\frac{p\Delta\omega_q - q\Delta\omega_p}{2\pi}\right|= \left| p\Delta f_q - q\Delta f_p\right|</math> Use <math>q\omega_p=p\omega_q \equiv qf_p=pf_q \equiv pT_p = qT_q</math> where <math>T=1/f</math> denotes period. Note that <math>\frac{\Delta f}{f}=-\frac{\Delta T}{T}\implies \Delta f = -\frac{\Delta T}{T^2}</math> <math>\frac{1}{T_b}=\left| \frac{q\Delta T_p}{T_p^2} - \frac{p\Delta T_q}{T_q^2} \right|= \left| \frac{p\Delta T_p-q\Delta T_q}{T_pT_q}\right|</math> ====Making one beat: N a large number==== Recalling that <math>p>q</math>, we now select a large number <math>N</math> and define a new period <math>\widetilde T_p</math> <math>NpT_p=NqT_q=(N-1)p\widetilde T_p \equiv T_c</math>. We will show that <math>T_c=T_b</math> <math>\Delta T_p = \widetilde T_p-T_p = \frac 1 N T_p</math> implies <math>N=\frac{T_p}{\Delta T_p}</math> where <math>\widetilde T_p=T_p+\Delta T_p</math>. What we have done: We slightly increased the period of the p wave in order to remove one cycle. Thus causes the new p wave to cycle through all phase differences. Define <math>T_c</math> to be the cycle time. Now find a formula: <math>NpT_p= T_c = \frac{T_p}{\Delta T_p}pT_p</math> implies <math>\frac 1 T_c =\frac{\Delta T_p}{T_p^2}\frac 1 p</math> <math>f_c= \frac{-f_p}{p} \frac{\Delta f_p}{f_p}</math> ==Fourier analysis== ''See also'' [[w:Kramers–Kronig relations]], [[w:Cauchy principal value]], [https://wiki.seg.org/wiki/Dictionary:Hilbert_transform]and [[w:Sokhotski–Plemelj theorem]] <math> \int_\infty^\infty e^{i\omega t}d\omega=2\pi\delta(t)</math> <math>\frac{1}{X+i\epsilon} = \frac {X}{X^2+ \epsilon^2} - i \pi \delta(X)</math> <math>\frac{1}{X+i\epsilon} = \frac {X}{X^2+ \epsilon^2} - \frac {i\epsilon}{X^2+ \epsilon^2}</math> <math>\frac 1 X = \text{pp} \frac 1 X -i\pi \delta(X)</math> ==Links== '''Basic''' * <u>[[Wikipedia:Beat (acoustics)]]</u>: The fact that Wikipedia only covers the basic ideas supports my contention that material beyond these well known topics will always be murky.<ref>{{cite journal |last= Weinberger |first= Norman |date= September 2006 |title= Music And The Brain |url= https://www.scientificamerican.com/article/music-and-the-brain-2006-09/ |journal= Scientific American |volume= 16 |issue= 3 |pages= 36-43 |doi= 10.1038/scientificamerican0906-36sp |accessdate=2022-08-04 }}</ref><ref>Note the inserted footnote templates regarding "verification" and "original research?" at [[w:special:permalink/1102305761]]. </ref> * <u>[http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/beat.html Hyperphysics: Sound/beat:]</u> parallels the Wikipedia article. * [https://www.omnicalculator.com/physics/beat-frequency <u>Omnicalculator's beat frequency demonstration</u>] effectively how the 3:2 rhythm pattern is just an ultra slow version of the consonant perfect fifth in music. '''Advanced (or otherwise different)''' * <u>[https://www.violinist.com/discussion/archive/18551/ Violinist.com]</u> discussion on using beats to tune a violin ==Footnotes== 0v5oufcyx6uzmkhrydaypwilexhhq0p 2414033 2414031 2022-08-13T06:22:02Z Guy vandegrift 813252 /* Making one beat: N a large number */ wikitext text/x-wiki [[Image:Beating Frequency.svg|thumb|300px|Diagram of beat frequency]] A '''beat''' is an [[w:Interference (wave propagation)|interference]] pattern between two [[w:sound|sounds]] of slightly different [[w:frequency|frequencies]], ''perceived'' as a periodic variation in [[w:amplitude (music)|volume]] whose rate is the [[w:Difference (mathematics)|difference]] of the two frequencies. The fundamentals of this topic are taught at some level in virtually every introductory high school or college course. [[w:Beat (acoustics)|Wikipedia]] features the figure shown and equations like, :<math> f_\text{beat} = f_2 - f_1 = \frac{1}{\tau_b} = \frac{\left|\omega_2-\omega_1\right|}{2\pi}</math> But topics beyond these fundamentals are rarely pursued, and for good reason. Much about how humans perceive beats in musical intervals is poorly understood. This Wikiversity resource is not so much aimed at answering difficult questions, but to offer students the the opportunity to [https://www.pinterest.com/pin/164662930098107644/ "mess around"] in a way that enhances one's understanding of mathematics and computer programming. ===beats-angular frequency: Algebra=== Simple case (unison):<math>T_\text{simple}^{-1}=(2\pi)^{-1}(\omega_2-\omega_1) \implies</math> <math>2\pi / T_b = \left|\omega_2-\omega_1\right|</math> Define interval ratio, <math>1<p/q<2</math>, where: <math>\omega_p=p\omega_0</math> and <math>\omega_q=q\omega_0</math> The the lowest common harmonic of <math>\omega_p</math> and <math>\omega_q</math> is <math>\omega_h=pq\omega_0</math> Replace <math>p\to p+\Delta p </math> and <math>q\to q+\Delta q </math> <math>2\pi / T_b = \left| (p+\Delta p)q\omega_0 - p(q+\Delta q)\omega_0 \right| = \left|p\Delta\omega_q - q\Delta\omega_p\right|</math> <math>f_b=\left|\frac{p\Delta\omega_q - q\Delta\omega_p}{2\pi}\right|= \left| p\Delta f_q - q\Delta f_p\right|</math> Use <math>q\omega_p=p\omega_q \equiv qf_p=pf_q \equiv pT_p = qT_q</math> where <math>T=1/f</math> denotes period. Note that <math>\frac{\Delta f}{f}=-\frac{\Delta T}{T}\implies \Delta f = -\frac{\Delta T}{T^2}</math> <math>\frac{1}{T_b}=\left| \frac{q\Delta T_p}{T_p^2} - \frac{p\Delta T_q}{T_q^2} \right|= \left| \frac{p\Delta T_p-q\Delta T_q}{T_pT_q}\right|</math> ====Making one beat: N a large number==== Recalling that <math>p>q</math>, we now select a large number <math>N</math> and define a new period <math>\widetilde T_p</math> <math>NpT_p=NqT_q=(N-1)p\widetilde T_p \equiv T_c</math>. We will show that <math>T_c=T_b</math> <math>\Delta T_p = \widetilde T_p-T_p = \frac 1 N T_p</math> implies <math>N=\frac{T_p}{\Delta T_p}</math> where <math>\widetilde T_p=T_p+\Delta T_p</math>. What we have done: We slightly increased the period of the p wave in order to remove one cycle. Thus causes the new p wave to cycle through all phase differences. Define <math>T_c</math> to be the cycle time. Now find a formula: <math>NpT_p= T_c = \frac{T_p}{\Delta T_p}pT_p</math> implies <math>\frac 1 T_c =\frac{\Delta T_p}{T_p^2}\frac 1 p</math> <math>f_c= \frac{-f_p}{p} \frac{\Delta f_p}{f_p}</math> I am almost certain this leads to: <math>f_c= -\frac{f_q}{q} \frac{\Delta f_q}{f_q} - \frac{f_p}{p} \frac{\Delta f_p}{f_p} </math> ==Fourier analysis== ''See also'' [[w:Kramers–Kronig relations]], [[w:Cauchy principal value]], [https://wiki.seg.org/wiki/Dictionary:Hilbert_transform]and [[w:Sokhotski–Plemelj theorem]] <math> \int_\infty^\infty e^{i\omega t}d\omega=2\pi\delta(t)</math> <math>\frac{1}{X+i\epsilon} = \frac {X}{X^2+ \epsilon^2} - i \pi \delta(X)</math> <math>\frac{1}{X+i\epsilon} = \frac {X}{X^2+ \epsilon^2} - \frac {i\epsilon}{X^2+ \epsilon^2}</math> <math>\frac 1 X = \text{pp} \frac 1 X -i\pi \delta(X)</math> ==Links== '''Basic''' * <u>[[Wikipedia:Beat (acoustics)]]</u>: The fact that Wikipedia only covers the basic ideas supports my contention that material beyond these well known topics will always be murky.<ref>{{cite journal |last= Weinberger |first= Norman |date= September 2006 |title= Music And The Brain |url= https://www.scientificamerican.com/article/music-and-the-brain-2006-09/ |journal= Scientific American |volume= 16 |issue= 3 |pages= 36-43 |doi= 10.1038/scientificamerican0906-36sp |accessdate=2022-08-04 }}</ref><ref>Note the inserted footnote templates regarding "verification" and "original research?" at [[w:special:permalink/1102305761]]. </ref> * <u>[http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/beat.html Hyperphysics: Sound/beat:]</u> parallels the Wikipedia article. * [https://www.omnicalculator.com/physics/beat-frequency <u>Omnicalculator's beat frequency demonstration</u>] effectively how the 3:2 rhythm pattern is just an ultra slow version of the consonant perfect fifth in music. '''Advanced (or otherwise different)''' * <u>[https://www.violinist.com/discussion/archive/18551/ Violinist.com]</u> discussion on using beats to tune a violin ==Footnotes== 4syt8ggq1roeqle9v16nsfvgzwbrbni 2414034 2414033 2022-08-13T06:22:47Z Guy vandegrift 813252 /* Making one beat: N a large number */ wikitext text/x-wiki [[Image:Beating Frequency.svg|thumb|300px|Diagram of beat frequency]] A '''beat''' is an [[w:Interference (wave propagation)|interference]] pattern between two [[w:sound|sounds]] of slightly different [[w:frequency|frequencies]], ''perceived'' as a periodic variation in [[w:amplitude (music)|volume]] whose rate is the [[w:Difference (mathematics)|difference]] of the two frequencies. The fundamentals of this topic are taught at some level in virtually every introductory high school or college course. [[w:Beat (acoustics)|Wikipedia]] features the figure shown and equations like, :<math> f_\text{beat} = f_2 - f_1 = \frac{1}{\tau_b} = \frac{\left|\omega_2-\omega_1\right|}{2\pi}</math> But topics beyond these fundamentals are rarely pursued, and for good reason. Much about how humans perceive beats in musical intervals is poorly understood. This Wikiversity resource is not so much aimed at answering difficult questions, but to offer students the the opportunity to [https://www.pinterest.com/pin/164662930098107644/ "mess around"] in a way that enhances one's understanding of mathematics and computer programming. ===beats-angular frequency: Algebra=== Simple case (unison):<math>T_\text{simple}^{-1}=(2\pi)^{-1}(\omega_2-\omega_1) \implies</math> <math>2\pi / T_b = \left|\omega_2-\omega_1\right|</math> Define interval ratio, <math>1<p/q<2</math>, where: <math>\omega_p=p\omega_0</math> and <math>\omega_q=q\omega_0</math> The the lowest common harmonic of <math>\omega_p</math> and <math>\omega_q</math> is <math>\omega_h=pq\omega_0</math> Replace <math>p\to p+\Delta p </math> and <math>q\to q+\Delta q </math> <math>2\pi / T_b = \left| (p+\Delta p)q\omega_0 - p(q+\Delta q)\omega_0 \right| = \left|p\Delta\omega_q - q\Delta\omega_p\right|</math> <math>f_b=\left|\frac{p\Delta\omega_q - q\Delta\omega_p}{2\pi}\right|= \left| p\Delta f_q - q\Delta f_p\right|</math> Use <math>q\omega_p=p\omega_q \equiv qf_p=pf_q \equiv pT_p = qT_q</math> where <math>T=1/f</math> denotes period. Note that <math>\frac{\Delta f}{f}=-\frac{\Delta T}{T}\implies \Delta f = -\frac{\Delta T}{T^2}</math> <math>\frac{1}{T_b}=\left| \frac{q\Delta T_p}{T_p^2} - \frac{p\Delta T_q}{T_q^2} \right|= \left| \frac{p\Delta T_p-q\Delta T_q}{T_pT_q}\right|</math> ====Making one beat: N a large number==== Recalling that <math>p>q</math>, we now select a large number <math>N</math> and define a new period <math>\widetilde T_p</math> <math>NpT_p=NqT_q=(N-1)p\widetilde T_p \equiv T_c</math>. We will show that <math>T_c=T_b</math> <math>\Delta T_p = \widetilde T_p-T_p = \frac 1 N T_p</math> implies <math>N=\frac{T_p}{\Delta T_p}</math> where <math>\widetilde T_p=T_p+\Delta T_p</math>. What we have done: We slightly increased the period of the p wave in order to remove one cycle. Thus causes the new p wave to cycle through all phase differences. Define <math>T_c</math> to be the cycle time. Now find a formula: <math>NpT_p= T_c = \frac{T_p}{\Delta T_p}pT_p</math> implies <math>\frac 1 T_c =\frac{\Delta T_p}{T_p^2}\frac 1 p</math> <math>f_c= \frac{-f_p}{p} \frac{\Delta f_p}{f_p} = </math> I am almost certain this leads to: <math>f_c= -\frac{f_q}{q} \frac{\Delta f_q}{f_q} - \frac{f_p}{p} \frac{\Delta f_p}{f_p} </math> ==Fourier analysis== ''See also'' [[w:Kramers–Kronig relations]], [[w:Cauchy principal value]], [https://wiki.seg.org/wiki/Dictionary:Hilbert_transform]and [[w:Sokhotski–Plemelj theorem]] <math> \int_\infty^\infty e^{i\omega t}d\omega=2\pi\delta(t)</math> <math>\frac{1}{X+i\epsilon} = \frac {X}{X^2+ \epsilon^2} - i \pi \delta(X)</math> <math>\frac{1}{X+i\epsilon} = \frac {X}{X^2+ \epsilon^2} - \frac {i\epsilon}{X^2+ \epsilon^2}</math> <math>\frac 1 X = \text{pp} \frac 1 X -i\pi \delta(X)</math> ==Links== '''Basic''' * <u>[[Wikipedia:Beat (acoustics)]]</u>: The fact that Wikipedia only covers the basic ideas supports my contention that material beyond these well known topics will always be murky.<ref>{{cite journal |last= Weinberger |first= Norman |date= September 2006 |title= Music And The Brain |url= https://www.scientificamerican.com/article/music-and-the-brain-2006-09/ |journal= Scientific American |volume= 16 |issue= 3 |pages= 36-43 |doi= 10.1038/scientificamerican0906-36sp |accessdate=2022-08-04 }}</ref><ref>Note the inserted footnote templates regarding "verification" and "original research?" at [[w:special:permalink/1102305761]]. </ref> * <u>[http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/beat.html Hyperphysics: Sound/beat:]</u> parallels the Wikipedia article. * [https://www.omnicalculator.com/physics/beat-frequency <u>Omnicalculator's beat frequency demonstration</u>] effectively how the 3:2 rhythm pattern is just an ultra slow version of the consonant perfect fifth in music. '''Advanced (or otherwise different)''' * <u>[https://www.violinist.com/discussion/archive/18551/ Violinist.com]</u> discussion on using beats to tune a violin ==Footnotes== nwmpjh8n4u7mkaqly8dzxnjidd02zlp 2414035 2414034 2022-08-13T06:24:36Z Guy vandegrift 813252 /* Making one beat: N a large number */ wikitext text/x-wiki [[Image:Beating Frequency.svg|thumb|300px|Diagram of beat frequency]] A '''beat''' is an [[w:Interference (wave propagation)|interference]] pattern between two [[w:sound|sounds]] of slightly different [[w:frequency|frequencies]], ''perceived'' as a periodic variation in [[w:amplitude (music)|volume]] whose rate is the [[w:Difference (mathematics)|difference]] of the two frequencies. The fundamentals of this topic are taught at some level in virtually every introductory high school or college course. [[w:Beat (acoustics)|Wikipedia]] features the figure shown and equations like, :<math> f_\text{beat} = f_2 - f_1 = \frac{1}{\tau_b} = \frac{\left|\omega_2-\omega_1\right|}{2\pi}</math> But topics beyond these fundamentals are rarely pursued, and for good reason. Much about how humans perceive beats in musical intervals is poorly understood. This Wikiversity resource is not so much aimed at answering difficult questions, but to offer students the the opportunity to [https://www.pinterest.com/pin/164662930098107644/ "mess around"] in a way that enhances one's understanding of mathematics and computer programming. ===beats-angular frequency: Algebra=== Simple case (unison):<math>T_\text{simple}^{-1}=(2\pi)^{-1}(\omega_2-\omega_1) \implies</math> <math>2\pi / T_b = \left|\omega_2-\omega_1\right|</math> Define interval ratio, <math>1<p/q<2</math>, where: <math>\omega_p=p\omega_0</math> and <math>\omega_q=q\omega_0</math> The the lowest common harmonic of <math>\omega_p</math> and <math>\omega_q</math> is <math>\omega_h=pq\omega_0</math> Replace <math>p\to p+\Delta p </math> and <math>q\to q+\Delta q </math> <math>2\pi / T_b = \left| (p+\Delta p)q\omega_0 - p(q+\Delta q)\omega_0 \right| = \left|p\Delta\omega_q - q\Delta\omega_p\right|</math> <math>f_b=\left|\frac{p\Delta\omega_q - q\Delta\omega_p}{2\pi}\right|= \left| p\Delta f_q - q\Delta f_p\right|</math> Use <math>q\omega_p=p\omega_q \equiv qf_p=pf_q \equiv pT_p = qT_q</math> where <math>T=1/f</math> denotes period. Note that <math>\frac{\Delta f}{f}=-\frac{\Delta T}{T}\implies \Delta f = -\frac{\Delta T}{T^2}</math> <math>\frac{1}{T_b}=\left| \frac{q\Delta T_p}{T_p^2} - \frac{p\Delta T_q}{T_q^2} \right|= \left| \frac{p\Delta T_p-q\Delta T_q}{T_pT_q}\right|</math> ====Making one beat: N a large number==== Recalling that <math>p>q</math>, we now select a large number <math>N</math> and define a new period <math>\widetilde T_p</math> <math>NpT_p=NqT_q=(N-1)p\widetilde T_p \equiv T_c</math>. We will show that <math>T_c=T_b</math> <math>\Delta T_p = \widetilde T_p-T_p = \frac 1 N T_p</math> implies <math>N=\frac{T_p}{\Delta T_p}</math> where <math>\widetilde T_p=T_p+\Delta T_p</math>. What we have done: We slightly increased the period of the p wave in order to remove one cycle. Thus causes the new p wave to cycle through all phase differences. Define <math>T_c</math> to be the cycle time. Now find a formula: <math>NpT_p= T_c = \frac{T_p}{\Delta T_p}pT_p</math> implies <math>\frac 1 T_c =\frac{\Delta T_p}{T_p^2}\frac 1 p</math> <math>f_c= \frac{-f_p}{p} \frac{\Delta f_p}{f_p} = -\frac{\Delta f_p}{q}</math> I am almost certain this leads to: <math>f_c= -\frac{\Delta f_q}{p} +\frac{\Delta f_p}{q} </math> ==Fourier analysis== ''See also'' [[w:Kramers–Kronig relations]], [[w:Cauchy principal value]], [https://wiki.seg.org/wiki/Dictionary:Hilbert_transform]and [[w:Sokhotski–Plemelj theorem]] <math> \int_\infty^\infty e^{i\omega t}d\omega=2\pi\delta(t)</math> <math>\frac{1}{X+i\epsilon} = \frac {X}{X^2+ \epsilon^2} - i \pi \delta(X)</math> <math>\frac{1}{X+i\epsilon} = \frac {X}{X^2+ \epsilon^2} - \frac {i\epsilon}{X^2+ \epsilon^2}</math> <math>\frac 1 X = \text{pp} \frac 1 X -i\pi \delta(X)</math> ==Links== '''Basic''' * <u>[[Wikipedia:Beat (acoustics)]]</u>: The fact that Wikipedia only covers the basic ideas supports my contention that material beyond these well known topics will always be murky.<ref>{{cite journal |last= Weinberger |first= Norman |date= September 2006 |title= Music And The Brain |url= https://www.scientificamerican.com/article/music-and-the-brain-2006-09/ |journal= Scientific American |volume= 16 |issue= 3 |pages= 36-43 |doi= 10.1038/scientificamerican0906-36sp |accessdate=2022-08-04 }}</ref><ref>Note the inserted footnote templates regarding "verification" and "original research?" at [[w:special:permalink/1102305761]]. </ref> * <u>[http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/beat.html Hyperphysics: Sound/beat:]</u> parallels the Wikipedia article. * [https://www.omnicalculator.com/physics/beat-frequency <u>Omnicalculator's beat frequency demonstration</u>] effectively how the 3:2 rhythm pattern is just an ultra slow version of the consonant perfect fifth in music. '''Advanced (or otherwise different)''' * <u>[https://www.violinist.com/discussion/archive/18551/ Violinist.com]</u> discussion on using beats to tune a violin ==Footnotes== hxirdphvbfm5zjphcka9mu6idbxmhch 2414036 2414035 2022-08-13T06:28:09Z Guy vandegrift 813252 /* Making one beat: N a large number */ wikitext text/x-wiki [[Image:Beating Frequency.svg|thumb|300px|Diagram of beat frequency]] A '''beat''' is an [[w:Interference (wave propagation)|interference]] pattern between two [[w:sound|sounds]] of slightly different [[w:frequency|frequencies]], ''perceived'' as a periodic variation in [[w:amplitude (music)|volume]] whose rate is the [[w:Difference (mathematics)|difference]] of the two frequencies. The fundamentals of this topic are taught at some level in virtually every introductory high school or college course. [[w:Beat (acoustics)|Wikipedia]] features the figure shown and equations like, :<math> f_\text{beat} = f_2 - f_1 = \frac{1}{\tau_b} = \frac{\left|\omega_2-\omega_1\right|}{2\pi}</math> But topics beyond these fundamentals are rarely pursued, and for good reason. Much about how humans perceive beats in musical intervals is poorly understood. This Wikiversity resource is not so much aimed at answering difficult questions, but to offer students the the opportunity to [https://www.pinterest.com/pin/164662930098107644/ "mess around"] in a way that enhances one's understanding of mathematics and computer programming. ===beats-angular frequency: Algebra=== Simple case (unison):<math>T_\text{simple}^{-1}=(2\pi)^{-1}(\omega_2-\omega_1) \implies</math> <math>2\pi / T_b = \left|\omega_2-\omega_1\right|</math> Define interval ratio, <math>1<p/q<2</math>, where: <math>\omega_p=p\omega_0</math> and <math>\omega_q=q\omega_0</math> The the lowest common harmonic of <math>\omega_p</math> and <math>\omega_q</math> is <math>\omega_h=pq\omega_0</math> Replace <math>p\to p+\Delta p </math> and <math>q\to q+\Delta q </math> <math>2\pi / T_b = \left| (p+\Delta p)q\omega_0 - p(q+\Delta q)\omega_0 \right| = \left|p\Delta\omega_q - q\Delta\omega_p\right|</math> <math>f_b=\left|\frac{p\Delta\omega_q - q\Delta\omega_p}{2\pi}\right|= \left| p\Delta f_q - q\Delta f_p\right|</math> Use <math>q\omega_p=p\omega_q \equiv qf_p=pf_q \equiv pT_p = qT_q</math> where <math>T=1/f</math> denotes period. Note that <math>\frac{\Delta f}{f}=-\frac{\Delta T}{T}\implies \Delta f = -\frac{\Delta T}{T^2}</math> <math>\frac{1}{T_b}=\left| \frac{q\Delta T_p}{T_p^2} - \frac{p\Delta T_q}{T_q^2} \right|= \left| \frac{p\Delta T_p-q\Delta T_q}{T_pT_q}\right|</math> ====Making one beat: N a large number==== Recalling that <math>p>q</math>, we now select a large number <math>N</math> and define a new period <math>\widetilde T_p</math> <math>NpT_p=NqT_q=(N-1)p\widetilde T_p \equiv T_c</math>. We will show that <math>T_c=T_b</math> <math>\Delta T_p = \widetilde T_p-T_p = \frac 1 N T_p</math> implies <math>N=\frac{T_p}{\Delta T_p}</math> where <math>\widetilde T_p=T_p+\Delta T_p</math>. What we have done: We slightly increased the period of the p wave in order to remove one cycle. Thus causes the new p wave to cycle through all phase differences. Define <math>T_c</math> to be the cycle time. Now find a formula: <math>NpT_p= T_c = \frac{T_p}{\Delta T_p}pT_p</math> implies <math>\frac 1 T_c =\frac{\Delta T_p}{T_p^2}\frac 1 p</math> <math>f_c= \frac{-f_p}{p} \frac{\Delta f_p}{f_p} = -\frac{\Delta f_p}{q}</math> I am almost certain this leads to: <math>f_c= \left|-\frac{\Delta f_q}{p} +\frac{\Delta f_p}{q} \right|= </math> ==Fourier analysis== ''See also'' [[w:Kramers–Kronig relations]], [[w:Cauchy principal value]], [https://wiki.seg.org/wiki/Dictionary:Hilbert_transform]and [[w:Sokhotski–Plemelj theorem]] <math> \int_\infty^\infty e^{i\omega t}d\omega=2\pi\delta(t)</math> <math>\frac{1}{X+i\epsilon} = \frac {X}{X^2+ \epsilon^2} - i \pi \delta(X)</math> <math>\frac{1}{X+i\epsilon} = \frac {X}{X^2+ \epsilon^2} - \frac {i\epsilon}{X^2+ \epsilon^2}</math> <math>\frac 1 X = \text{pp} \frac 1 X -i\pi \delta(X)</math> ==Links== '''Basic''' * <u>[[Wikipedia:Beat (acoustics)]]</u>: The fact that Wikipedia only covers the basic ideas supports my contention that material beyond these well known topics will always be murky.<ref>{{cite journal |last= Weinberger |first= Norman |date= September 2006 |title= Music And The Brain |url= https://www.scientificamerican.com/article/music-and-the-brain-2006-09/ |journal= Scientific American |volume= 16 |issue= 3 |pages= 36-43 |doi= 10.1038/scientificamerican0906-36sp |accessdate=2022-08-04 }}</ref><ref>Note the inserted footnote templates regarding "verification" and "original research?" at [[w:special:permalink/1102305761]]. </ref> * <u>[http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/beat.html Hyperphysics: Sound/beat:]</u> parallels the Wikipedia article. * [https://www.omnicalculator.com/physics/beat-frequency <u>Omnicalculator's beat frequency demonstration</u>] effectively how the 3:2 rhythm pattern is just an ultra slow version of the consonant perfect fifth in music. '''Advanced (or otherwise different)''' * <u>[https://www.violinist.com/discussion/archive/18551/ Violinist.com]</u> discussion on using beats to tune a violin ==Footnotes== 1efj0fbg7ie6lsfl50pt6t7muzhz1j1 2414037 2414036 2022-08-13T06:29:36Z Guy vandegrift 813252 /* Making one beat: N a large number */ wikitext text/x-wiki [[Image:Beating Frequency.svg|thumb|300px|Diagram of beat frequency]] A '''beat''' is an [[w:Interference (wave propagation)|interference]] pattern between two [[w:sound|sounds]] of slightly different [[w:frequency|frequencies]], ''perceived'' as a periodic variation in [[w:amplitude (music)|volume]] whose rate is the [[w:Difference (mathematics)|difference]] of the two frequencies. The fundamentals of this topic are taught at some level in virtually every introductory high school or college course. [[w:Beat (acoustics)|Wikipedia]] features the figure shown and equations like, :<math> f_\text{beat} = f_2 - f_1 = \frac{1}{\tau_b} = \frac{\left|\omega_2-\omega_1\right|}{2\pi}</math> But topics beyond these fundamentals are rarely pursued, and for good reason. Much about how humans perceive beats in musical intervals is poorly understood. This Wikiversity resource is not so much aimed at answering difficult questions, but to offer students the the opportunity to [https://www.pinterest.com/pin/164662930098107644/ "mess around"] in a way that enhances one's understanding of mathematics and computer programming. ===beats-angular frequency: Algebra=== Simple case (unison):<math>T_\text{simple}^{-1}=(2\pi)^{-1}(\omega_2-\omega_1) \implies</math> <math>2\pi / T_b = \left|\omega_2-\omega_1\right|</math> Define interval ratio, <math>1<p/q<2</math>, where: <math>\omega_p=p\omega_0</math> and <math>\omega_q=q\omega_0</math> The the lowest common harmonic of <math>\omega_p</math> and <math>\omega_q</math> is <math>\omega_h=pq\omega_0</math> Replace <math>p\to p+\Delta p </math> and <math>q\to q+\Delta q </math> <math>2\pi / T_b = \left| (p+\Delta p)q\omega_0 - p(q+\Delta q)\omega_0 \right| = \left|p\Delta\omega_q - q\Delta\omega_p\right|</math> <math>f_b=\left|\frac{p\Delta\omega_q - q\Delta\omega_p}{2\pi}\right|= \left| p\Delta f_q - q\Delta f_p\right|</math> Use <math>q\omega_p=p\omega_q \equiv qf_p=pf_q \equiv pT_p = qT_q</math> where <math>T=1/f</math> denotes period. Note that <math>\frac{\Delta f}{f}=-\frac{\Delta T}{T}\implies \Delta f = -\frac{\Delta T}{T^2}</math> <math>\frac{1}{T_b}=\left| \frac{q\Delta T_p}{T_p^2} - \frac{p\Delta T_q}{T_q^2} \right|= \left| \frac{p\Delta T_p-q\Delta T_q}{T_pT_q}\right|</math> ====Making one beat: N a large number==== Recalling that <math>p>q</math>, we now select a large number <math>N</math> and define a new period <math>\widetilde T_p</math> <math>NpT_p=NqT_q=(N-1)p\widetilde T_p \equiv T_c</math>. We will show that <math>T_c=T_b</math> <math>\Delta T_p = \widetilde T_p-T_p = \frac 1 N T_p</math> implies <math>N=\frac{T_p}{\Delta T_p}</math> where <math>\widetilde T_p=T_p+\Delta T_p</math>. What we have done: We slightly increased the period of the p wave in order to remove one cycle. Thus causes the new p wave to cycle through all phase differences. Define <math>T_c</math> to be the cycle time. Now find a formula: <math>NpT_p= T_c = \frac{T_p}{\Delta T_p}pT_p</math> implies <math>\frac 1 T_c =\frac{\Delta T_p}{T_p^2}\frac 1 p</math> <math>f_c= \frac{-f_p}{p} \frac{\Delta f_p}{f_p} = -\frac{\Delta f_p}{q}</math> I am almost certain this leads to: <math>f_c= \left|-\frac{\Delta f_q}{p} +\frac{\Delta f_p}{q} \right|= \frac{f_b}{pq} </math> ==Fourier analysis== ''See also'' [[w:Kramers–Kronig relations]], [[w:Cauchy principal value]], [https://wiki.seg.org/wiki/Dictionary:Hilbert_transform]and [[w:Sokhotski–Plemelj theorem]] <math> \int_\infty^\infty e^{i\omega t}d\omega=2\pi\delta(t)</math> <math>\frac{1}{X+i\epsilon} = \frac {X}{X^2+ \epsilon^2} - i \pi \delta(X)</math> <math>\frac{1}{X+i\epsilon} = \frac {X}{X^2+ \epsilon^2} - \frac {i\epsilon}{X^2+ \epsilon^2}</math> <math>\frac 1 X = \text{pp} \frac 1 X -i\pi \delta(X)</math> ==Links== '''Basic''' * <u>[[Wikipedia:Beat (acoustics)]]</u>: The fact that Wikipedia only covers the basic ideas supports my contention that material beyond these well known topics will always be murky.<ref>{{cite journal |last= Weinberger |first= Norman |date= September 2006 |title= Music And The Brain |url= https://www.scientificamerican.com/article/music-and-the-brain-2006-09/ |journal= Scientific American |volume= 16 |issue= 3 |pages= 36-43 |doi= 10.1038/scientificamerican0906-36sp |accessdate=2022-08-04 }}</ref><ref>Note the inserted footnote templates regarding "verification" and "original research?" at [[w:special:permalink/1102305761]]. </ref> * <u>[http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/beat.html Hyperphysics: Sound/beat:]</u> parallels the Wikipedia article. * [https://www.omnicalculator.com/physics/beat-frequency <u>Omnicalculator's beat frequency demonstration</u>] effectively how the 3:2 rhythm pattern is just an ultra slow version of the consonant perfect fifth in music. '''Advanced (or otherwise different)''' * <u>[https://www.violinist.com/discussion/archive/18551/ Violinist.com]</u> discussion on using beats to tune a violin ==Footnotes== tq1oagc27lsql223in46uh35khb8br9 2414039 2414037 2022-08-13T06:35:30Z Guy vandegrift 813252 /* Making one beat: N a large number */ wikitext text/x-wiki [[Image:Beating Frequency.svg|thumb|300px|Diagram of beat frequency]] A '''beat''' is an [[w:Interference (wave propagation)|interference]] pattern between two [[w:sound|sounds]] of slightly different [[w:frequency|frequencies]], ''perceived'' as a periodic variation in [[w:amplitude (music)|volume]] whose rate is the [[w:Difference (mathematics)|difference]] of the two frequencies. The fundamentals of this topic are taught at some level in virtually every introductory high school or college course. [[w:Beat (acoustics)|Wikipedia]] features the figure shown and equations like, :<math> f_\text{beat} = f_2 - f_1 = \frac{1}{\tau_b} = \frac{\left|\omega_2-\omega_1\right|}{2\pi}</math> But topics beyond these fundamentals are rarely pursued, and for good reason. Much about how humans perceive beats in musical intervals is poorly understood. This Wikiversity resource is not so much aimed at answering difficult questions, but to offer students the the opportunity to [https://www.pinterest.com/pin/164662930098107644/ "mess around"] in a way that enhances one's understanding of mathematics and computer programming. ===beats-angular frequency: Algebra=== Simple case (unison):<math>T_\text{simple}^{-1}=(2\pi)^{-1}(\omega_2-\omega_1) \implies</math> <math>2\pi / T_b = \left|\omega_2-\omega_1\right|</math> Define interval ratio, <math>1<p/q<2</math>, where: <math>\omega_p=p\omega_0</math> and <math>\omega_q=q\omega_0</math> The the lowest common harmonic of <math>\omega_p</math> and <math>\omega_q</math> is <math>\omega_h=pq\omega_0</math> Replace <math>p\to p+\Delta p </math> and <math>q\to q+\Delta q </math> <math>2\pi / T_b = \left| (p+\Delta p)q\omega_0 - p(q+\Delta q)\omega_0 \right| = \left|p\Delta\omega_q - q\Delta\omega_p\right|</math> <math>f_b=\left|\frac{p\Delta\omega_q - q\Delta\omega_p}{2\pi}\right|= \left| p\Delta f_q - q\Delta f_p\right|</math> Use <math>q\omega_p=p\omega_q \equiv qf_p=pf_q \equiv pT_p = qT_q</math> where <math>T=1/f</math> denotes period. Note that <math>\frac{\Delta f}{f}=-\frac{\Delta T}{T}\implies \Delta f = -\frac{\Delta T}{T^2}</math> <math>\frac{1}{T_b}=\left| \frac{q\Delta T_p}{T_p^2} - \frac{p\Delta T_q}{T_q^2} \right|= \left| \frac{p\Delta T_p-q\Delta T_q}{T_pT_q}\right|</math> ====Making one beat: N a large number==== Recalling that <math>p>q</math>, we now select a large number <math>N</math> and define a new period <math>\widetilde T_p</math> <math>NpT_p=NqT_q=(N-1)p\widetilde T_p \equiv T_c</math>. We will show that <math>T_c=T_b</math> <math>\Delta T_p = \widetilde T_p-T_p = \frac 1 N T_p</math> implies <math>N=\frac{T_p}{\Delta T_p}</math> where <math>\widetilde T_p=T_p+\Delta T_p</math>. What we have done: We slightly increased the period of the p wave in order to remove one cycle. Thus causes the new p wave to cycle through all phase differences. Define <math>T_c</math> to be the cycle time. Now find a formula: <math>NpT_p= T_c = \frac{T_p}{\Delta T_p}pT_p</math> implies <math>\frac 1 T_c =\frac{\Delta T_p}{T_p^2}\frac 1 p</math> <math>f_c= \frac{-f_p}{p} \frac{\Delta f_p}{f_p} = -\frac{\Delta f_p}{q}</math> I am almost certain this leads to: <math>f_c= \left|-\frac{\Delta f_q}{p} +\frac{\Delta f_p}{q} \right|= \frac{f_b}{pq} </math> <nowiki>****</nowiki> RE CASE WHERE P=3 AND Q=2 AND Fc=.5Fp IF P WAS CHANGED*** NOW WE ARE OFF BY A FACTOR OF 3 (SINCE P=2 WAS CHANGED <nowiki>******</nowiki> ==Fourier analysis== ''See also'' [[w:Kramers–Kronig relations]], [[w:Cauchy principal value]], [https://wiki.seg.org/wiki/Dictionary:Hilbert_transform]and [[w:Sokhotski–Plemelj theorem]] <math> \int_\infty^\infty e^{i\omega t}d\omega=2\pi\delta(t)</math> <math>\frac{1}{X+i\epsilon} = \frac {X}{X^2+ \epsilon^2} - i \pi \delta(X)</math> <math>\frac{1}{X+i\epsilon} = \frac {X}{X^2+ \epsilon^2} - \frac {i\epsilon}{X^2+ \epsilon^2}</math> <math>\frac 1 X = \text{pp} \frac 1 X -i\pi \delta(X)</math> ==Links== '''Basic''' * <u>[[Wikipedia:Beat (acoustics)]]</u>: The fact that Wikipedia only covers the basic ideas supports my contention that material beyond these well known topics will always be murky.<ref>{{cite journal |last= Weinberger |first= Norman |date= September 2006 |title= Music And The Brain |url= https://www.scientificamerican.com/article/music-and-the-brain-2006-09/ |journal= Scientific American |volume= 16 |issue= 3 |pages= 36-43 |doi= 10.1038/scientificamerican0906-36sp |accessdate=2022-08-04 }}</ref><ref>Note the inserted footnote templates regarding "verification" and "original research?" at [[w:special:permalink/1102305761]]. </ref> * <u>[http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/beat.html Hyperphysics: Sound/beat:]</u> parallels the Wikipedia article. * [https://www.omnicalculator.com/physics/beat-frequency <u>Omnicalculator's beat frequency demonstration</u>] effectively how the 3:2 rhythm pattern is just an ultra slow version of the consonant perfect fifth in music. '''Advanced (or otherwise different)''' * <u>[https://www.violinist.com/discussion/archive/18551/ Violinist.com]</u> discussion on using beats to tune a violin ==Footnotes== phvqhh5kd1g2yltbhs5r7f1ubc6p7og 2414040 2414039 2022-08-13T06:40:42Z Guy vandegrift 813252 /* Making one beat: N a large number */ wikitext text/x-wiki [[Image:Beating Frequency.svg|thumb|300px|Diagram of beat frequency]] A '''beat''' is an [[w:Interference (wave propagation)|interference]] pattern between two [[w:sound|sounds]] of slightly different [[w:frequency|frequencies]], ''perceived'' as a periodic variation in [[w:amplitude (music)|volume]] whose rate is the [[w:Difference (mathematics)|difference]] of the two frequencies. The fundamentals of this topic are taught at some level in virtually every introductory high school or college course. [[w:Beat (acoustics)|Wikipedia]] features the figure shown and equations like, :<math> f_\text{beat} = f_2 - f_1 = \frac{1}{\tau_b} = \frac{\left|\omega_2-\omega_1\right|}{2\pi}</math> But topics beyond these fundamentals are rarely pursued, and for good reason. Much about how humans perceive beats in musical intervals is poorly understood. This Wikiversity resource is not so much aimed at answering difficult questions, but to offer students the the opportunity to [https://www.pinterest.com/pin/164662930098107644/ "mess around"] in a way that enhances one's understanding of mathematics and computer programming. ===beats-angular frequency: Algebra=== Simple case (unison):<math>T_\text{simple}^{-1}=(2\pi)^{-1}(\omega_2-\omega_1) \implies</math> <math>2\pi / T_b = \left|\omega_2-\omega_1\right|</math> Define interval ratio, <math>1<p/q<2</math>, where: <math>\omega_p=p\omega_0</math> and <math>\omega_q=q\omega_0</math> The the lowest common harmonic of <math>\omega_p</math> and <math>\omega_q</math> is <math>\omega_h=pq\omega_0</math> Replace <math>p\to p+\Delta p </math> and <math>q\to q+\Delta q </math> <math>2\pi / T_b = \left| (p+\Delta p)q\omega_0 - p(q+\Delta q)\omega_0 \right| = \left|p\Delta\omega_q - q\Delta\omega_p\right|</math> <math>f_b=\left|\frac{p\Delta\omega_q - q\Delta\omega_p}{2\pi}\right|= \left| p\Delta f_q - q\Delta f_p\right|</math> Use <math>q\omega_p=p\omega_q \equiv qf_p=pf_q \equiv pT_p = qT_q</math> where <math>T=1/f</math> denotes period. Note that <math>\frac{\Delta f}{f}=-\frac{\Delta T}{T}\implies \Delta f = -\frac{\Delta T}{T^2}</math> <math>\frac{1}{T_b}=\left| \frac{q\Delta T_p}{T_p^2} - \frac{p\Delta T_q}{T_q^2} \right|= \left| \frac{p\Delta T_p-q\Delta T_q}{T_pT_q}\right|</math> ====Making one beat: N a large number==== Recalling that <math>p>q</math>, we now select a large number <math>N</math> and define a new period <math>\widetilde T_p</math> <math>NpT_p=NqT_q=(N-1)p\widetilde T_p \equiv T_c</math>. We will show that <math>T_c=T_b</math> <math>\Delta T_p = \widetilde T_p-T_p = \frac 1 N T_p</math> implies <math>N=\frac{T_p}{\Delta T_p}</math> where <math>\widetilde T_p=T_p+\Delta T_p</math>. What we have done: We slightly increased the period of the p wave in order to remove one cycle. Thus causes the new p wave to cycle through all phase differences. Define <math>T_c</math> to be the cycle time. Now find a formula: <math>NpT_p= T_c = \frac{T_p}{\Delta T_p}pT_p</math> implies <math>\frac 1 T_c =\frac{\Delta T_p}{T_p^2}\frac 1 p</math> <math>f_c= \frac{-f_p}{p} \frac{\Delta f_p}{f_p} = -\frac{\Delta f_p}{q}</math> I am almost certain this leads to: <math>f_c= \left|-\frac{\Delta f_q}{p} +\frac{\Delta f_p}{q} \right|= \frac{f_b}{pq} </math> <nowiki>****</nowiki> RE CASE WHERE P=3 AND Q=2 AND Fc=.5Fp IF P WAS CHANGED**** p , q = 3, 2 f_0 = 100 f_p, Df_p = p*f_0, 10 f_q, Df_q = q*f_0, 0 ==Fourier analysis== ''See also'' [[w:Kramers–Kronig relations]], [[w:Cauchy principal value]], [https://wiki.seg.org/wiki/Dictionary:Hilbert_transform]and [[w:Sokhotski–Plemelj theorem]] <math> \int_\infty^\infty e^{i\omega t}d\omega=2\pi\delta(t)</math> <math>\frac{1}{X+i\epsilon} = \frac {X}{X^2+ \epsilon^2} - i \pi \delta(X)</math> <math>\frac{1}{X+i\epsilon} = \frac {X}{X^2+ \epsilon^2} - \frac {i\epsilon}{X^2+ \epsilon^2}</math> <math>\frac 1 X = \text{pp} \frac 1 X -i\pi \delta(X)</math> ==Links== '''Basic''' * <u>[[Wikipedia:Beat (acoustics)]]</u>: The fact that Wikipedia only covers the basic ideas supports my contention that material beyond these well known topics will always be murky.<ref>{{cite journal |last= Weinberger |first= Norman |date= September 2006 |title= Music And The Brain |url= https://www.scientificamerican.com/article/music-and-the-brain-2006-09/ |journal= Scientific American |volume= 16 |issue= 3 |pages= 36-43 |doi= 10.1038/scientificamerican0906-36sp |accessdate=2022-08-04 }}</ref><ref>Note the inserted footnote templates regarding "verification" and "original research?" at [[w:special:permalink/1102305761]]. </ref> * <u>[http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/beat.html Hyperphysics: Sound/beat:]</u> parallels the Wikipedia article. * [https://www.omnicalculator.com/physics/beat-frequency <u>Omnicalculator's beat frequency demonstration</u>] effectively how the 3:2 rhythm pattern is just an ultra slow version of the consonant perfect fifth in music. '''Advanced (or otherwise different)''' * <u>[https://www.violinist.com/discussion/archive/18551/ Violinist.com]</u> discussion on using beats to tune a violin ==Footnotes== 6iy7yd3qp4lnresypmfggwm1onkeidn 0 286140 2414007 2413714 2022-08-12T20:52:16Z JimmyOC1985 2925861 wikitext text/x-wiki # [[Motivation and emotion/Book/2022/Cognitive entrenchment|Cognitive entrenchment]] - What is cognitive entrenchment and how can it be avoided? - [[JimmyOC1985]] t7sq4mklozr0dzho1x51q49ea8lhmim 2 286218 2414029 2413182 2022-08-13T06:13:19Z U3203545 2947578 /* About Me */ wikitext text/x-wiki == About Me == Hi, I am a 3rd Year Psychology student studying the unit 'Motivation & Emotion.' My university journey has taught me valuable skills which can be translated into the workplace and has allowed me to expand my knowledge on various topics. == Hobbies == * Reading * Watercolour Painting * Overthinking * Nature Walking == Book Chapter I'm Working On == Compassion - What is compassion, what are its pros and cons, and how can it be fostered? ctma7i3x9m9ywt978vhcdjqv5qa47wp 2414032 2414029 2022-08-13T06:21:43Z U3203545 2947578 wikitext text/x-wiki == About Me == Hi, I am a 3rd Year Psychology student studying the unit 'Motivation & Emotion.' My university journey has taught me valuable skills which can be translated into the workplace and has allowed me to expand my knowledge on various topics. == Hobbies == * Reading * Watercolour Painting * Overthinking * Nature Walking == Book Chapter I'm Working On == Compassion - What is compassion, what are its pros and cons, and how can it be fostered? 940r9ffovct4c3rlot7wdy98vxoska7 6 286302 2413961 2022-08-12T14:06:54Z Young1lim 21186 {{Information |Description=Laurent.5: Applications 6A (20220811 - 20220810) |Source={{own|Young1lim}} |Date=2022-08-12 |Author=Young W. Lim |Permission={{cc-by-sa-3.0,2.5,2.0,1.0}} }} wikitext text/x-wiki == Summary == {{Information |Description=Laurent.5: Applications 6A (20220811 - 20220810) |Source={{own|Young1lim}} |Date=2022-08-12 |Author=Young W. Lim |Permission={{cc-by-sa-3.0,2.5,2.0,1.0}} }} == Licensing == {{self|GFDL|cc-by-sa-4.0,3.0,2.5,2.0,1.0}} a9lniqhlxn3ozifpp1lhidxhlo8ffd3 6 286303 2413962 2022-08-12T14:08:15Z Young1lim 21186 {{Information |Description=C04.Series.3: Array Pointers 1A (20220811 - 20220810) |Source={{own|Young1lim}} |Date=2022-08-12 |Author=Young W. Lim |Permission={{GFDL}} }} wikitext text/x-wiki == Summary == {{Information |Description=C04.Series.3: Array Pointers 1A (20220811 - 20220810) |Source={{own|Young1lim}} |Date=2022-08-12 |Author=Young W. Lim |Permission={{GFDL}} }} == Licensing == {{self|GFDL|cc-by-sa-4.0,3.0,2.5,2.0,1.0}} 19jk0c76j29uxg0tzp1tz80ab20ezge 6 286304 2413963 2022-08-12T14:08:42Z Young1lim 21186 {{Information |Description=C04.Series.1: Arrays 1A (20220811 - 20220810) |Source={{own|Young1lim}} |Date=2022-08-12 |Author=Young W. Lim |Permission={{GFDL}} }} wikitext text/x-wiki == Summary == {{Information |Description=C04.Series.1: Arrays 1A (20220811 - 20220810) |Source={{own|Young1lim}} |Date=2022-08-12 |Author=Young W. Lim |Permission={{GFDL}} }} == Licensing == {{self|GFDL|cc-by-sa-4.0,3.0,2.5,2.0,1.0}} npf28937zme11vhm2sktwnqc0ureoxb 6 286305 2413964 2022-08-12T14:09:57Z Young1lim 21186 {{Information |Description=C04.Series.1App: Applications of Arrays 1A (20220811- 20220810) |Source={{own|Young1lim}} |Date=2022-08-12 |Author=Young W. Lim |Permission={{GFDL}} }} wikitext text/x-wiki == Summary == {{Information |Description=C04.Series.1App: Applications of Arrays 1A (20220811- 20220810) |Source={{own|Young1lim}} |Date=2022-08-12 |Author=Young W. Lim |Permission={{GFDL}} }} == Licensing == {{self|GFDL|cc-by-sa-4.0,3.0,2.5,2.0,1.0}} mqiz61zrtm54jyejx8ub7sbox7wf8xw 6 286306 2413965 2022-08-12T14:11:10Z Young1lim 21186 {{Information |Description=VLSI.Arith.1.A: Variable Block Adders (20220811 - 20220810) |Source={{own|Young1lim}} |Date=2022-08-12 |Author=Young W. Lim |Permission={{GFDL}} }} wikitext text/x-wiki == Summary == {{Information |Description=VLSI.Arith.1.A: Variable Block Adders (20220811 - 20220810) |Source={{own|Young1lim}} |Date=2022-08-12 |Author=Young W. Lim |Permission={{GFDL}} }} == Licensing == {{self|GFDL|cc-by-sa-4.0,3.0,2.5,2.0,1.0}} 06xo31dn95bh9xsbkryvebsde8su7w7 3 286307 2413967 2022-08-12T14:39:03Z Dave Braunschweig 426084 Welcome wikitext text/x-wiki {{Robelbox|theme=9|title=Welcome!|width=100%}} <div style="{{Robelbox/pad}}"> '''Hello and [[Wikiversity:Welcome|Welcome]] to [[Wikiversity:What is Wikiversity|Wikiversity]] AEMOR!''' You can [[Wikiversity:Contact|contact us]] with [[Wikiversity:Questions|questions]] at the [[Wikiversity:Colloquium|colloquium]] or [[User talk:Dave Braunschweig|me personally]] when you need [[Help:Contents|help]]. Please remember to [[Wikiversity:Signature|sign and date]] your finished comments when [[Wikiversity:Who are Wikiversity participants?|participating]] in [[Wikiversity:Talk page|discussions]]. The signature icon [[File:OOjs UI icon signature-ltr.svg]] above the edit window makes it simple. All users are expected to abide by our [[Wikiversity:Privacy policy|Privacy]], [[Wikiversity:Civility|Civility]], and the [[Foundation:Terms of Use|Terms of Use]] policies while at Wikiversity. To [[Wikiversity:Introduction|get started]], you may <!-- The Left column --> <div style="width:50.0%; float:left"> * [[Help:guides|Take a guided tour]] and learn [[Help:Editing|to edit]]. * Visit a (kind of) [[Wikiversity:Random|random project]]. * [[Wikiversity:Browse|Browse]] Wikiversity, or visit a portal corresponding to your educational level: [[Portal: Pre-school Education|pre-school]], [[Portal: Primary Education|primary]], [[Portal:Secondary Education|secondary]], [[Portal:Tertiary Education|tertiary]], [[Portal:Non-formal Education|non-formal education]]. * Find out about [[Wikiversity:Research|research]] activities on Wikiversity. * [[Wikiversity:Introduction explore|Explore]] Wikiversity with the links to your left. </div> <!-- The Right column --> <div style="width:50.0%; float:left"> * Enable VisualEditor under [[Special:Preferences#mw-prefsection-betafeatures|Beta]] settings to make article editing easier. * Read an [[Wikiversity:Wikiversity teachers|introduction for teachers]] and find out [[Help:How to write an educational resource|how to write an educational resource]] for Wikiversity. * Give [[Wikiversity:Feedback|feedback]] about your initial observations. * Discuss Wikiversity issues or ask questions at the [[Wikiversity:Colloquium|colloquium]]. * [[Wikiversity:Chat|Chat]] with other Wikiversitans on [[:freenode:wikiversity|<kbd>#wikiversity</kbd>]]. </div> <br clear="both"/> You do not need to be an educator to edit. You only need to [[Wikiversity:Be bold|be bold]] to contribute and to experiment with the [[wikiversity:sandbox|sandbox]] or [[special:mypage|your userpage]]. See you around Wikiversity! --[[User:Dave Braunschweig|Dave Braunschweig]] ([[User talk:Dave Braunschweig|discuss]] • [[Special:Contributions/Dave Braunschweig|contribs]]) 14:39, 12 August 2022 (UTC)</div> <!-- Template:Welcome --> {{Robelbox/close}} j86c0fzhkvvim2qf20x9cvdsavrkf8c 3 286308 2413968 2022-08-12T14:41:11Z Dave Braunschweig 426084 Welcome wikitext text/x-wiki {{Robelbox|theme=9|title=Welcome!|width=100%}} <div style="{{Robelbox/pad}}"> '''Hello and [[Wikiversity:Welcome|Welcome]] to [[Wikiversity:What is Wikiversity|Wikiversity]] Faggetmutilator!''' You can [[Wikiversity:Contact|contact us]] with [[Wikiversity:Questions|questions]] at the [[Wikiversity:Colloquium|colloquium]] or [[User talk:Dave Braunschweig|me personally]] when you need [[Help:Contents|help]]. Please remember to [[Wikiversity:Signature|sign and date]] your finished comments when [[Wikiversity:Who are Wikiversity participants?|participating]] in [[Wikiversity:Talk page|discussions]]. The signature icon [[File:OOjs UI icon signature-ltr.svg]] above the edit window makes it simple. All users are expected to abide by our [[Wikiversity:Privacy policy|Privacy]], [[Wikiversity:Civility|Civility]], and the [[Foundation:Terms of Use|Terms of Use]] policies while at Wikiversity. To [[Wikiversity:Introduction|get started]], you may <!-- The Left column --> <div style="width:50.0%; float:left"> * [[Help:guides|Take a guided tour]] and learn [[Help:Editing|to edit]]. * Visit a (kind of) [[Wikiversity:Random|random project]]. * [[Wikiversity:Browse|Browse]] Wikiversity, or visit a portal corresponding to your educational level: [[Portal: Pre-school Education|pre-school]], [[Portal: Primary Education|primary]], [[Portal:Secondary Education|secondary]], [[Portal:Tertiary Education|tertiary]], [[Portal:Non-formal Education|non-formal education]]. * Find out about [[Wikiversity:Research|research]] activities on Wikiversity. * [[Wikiversity:Introduction explore|Explore]] Wikiversity with the links to your left. </div> <!-- The Right column --> <div style="width:50.0%; float:left"> * Enable VisualEditor under [[Special:Preferences#mw-prefsection-betafeatures|Beta]] settings to make article editing easier. * Read an [[Wikiversity:Wikiversity teachers|introduction for teachers]] and find out [[Help:How to write an educational resource|how to write an educational resource]] for Wikiversity. * Give [[Wikiversity:Feedback|feedback]] about your initial observations. * Discuss Wikiversity issues or ask questions at the [[Wikiversity:Colloquium|colloquium]]. * [[Wikiversity:Chat|Chat]] with other Wikiversitans on [[:freenode:wikiversity|<kbd>#wikiversity</kbd>]]. </div> <br clear="both"/> You do not need to be an educator to edit. You only need to [[Wikiversity:Be bold|be bold]] to contribute and to experiment with the [[wikiversity:sandbox|sandbox]] or [[special:mypage|your userpage]]. See you around Wikiversity! --[[User:Dave Braunschweig|Dave Braunschweig]] ([[User talk:Dave Braunschweig|discuss]] • [[Special:Contributions/Dave Braunschweig|contribs]]) 14:41, 12 August 2022 (UTC)</div> <!-- Template:Welcome --> {{Robelbox/close}} 54snhzrishajfjblx09rhfm32il9dgh 2413971 2413968 2022-08-12T14:51:43Z Dave Braunschweig 426084 Blocked User wikitext text/x-wiki == Blocked User == Your account is blocked for two reasons. First, your selected username is offensive. Second, your contribution at [https://en.wikiversity.org/w/index.php?title=Talk:Evidence-based_assessment/Autism_spectrum_disorder_(assessment_portfolio)&diff=prev&oldid=2413917] is offensive and trolling. Your user page indicates that you are studying wiki engagement. Please note that this type of engagement is not welcome at Wikiversity. If you are actually studying wiki engagement, please create a legitimate user account and contribute positively to Wikiversity. If your interest is in studying wiki disruption, please have your professor contact me to discuss. There are plenty of examples that may be used without creating new disruptions. -- [[User:Dave Braunschweig|Dave Braunschweig]] ([[User talk:Dave Braunschweig|discuss]] • [[Special:Contributions/Dave Braunschweig|contribs]]) 14:51, 12 August 2022 (UTC) qehpyju98gbjpup7203ybywyyo6w9kt 3 286309 2413969 2022-08-12T14:42:59Z Dave Braunschweig 426084 Welcome wikitext text/x-wiki {{Robelbox|theme=9|title=Welcome!|width=100%}} <div style="{{Robelbox/pad}}"> '''Hello and [[Wikiversity:Welcome|Welcome]] to [[Wikiversity:What is Wikiversity|Wikiversity]] Giovannihbartlett!''' You can [[Wikiversity:Contact|contact us]] with [[Wikiversity:Questions|questions]] at the [[Wikiversity:Colloquium|colloquium]] or [[User talk:Dave Braunschweig|me personally]] when you need [[Help:Contents|help]]. Please remember to [[Wikiversity:Signature|sign and date]] your finished comments when [[Wikiversity:Who are Wikiversity participants?|participating]] in [[Wikiversity:Talk page|discussions]]. The signature icon [[File:OOjs UI icon signature-ltr.svg]] above the edit window makes it simple. All users are expected to abide by our [[Wikiversity:Privacy policy|Privacy]], [[Wikiversity:Civility|Civility]], and the [[Foundation:Terms of Use|Terms of Use]] policies while at Wikiversity. To [[Wikiversity:Introduction|get started]], you may <!-- The Left column --> <div style="width:50.0%; float:left"> * [[Help:guides|Take a guided tour]] and learn [[Help:Editing|to edit]]. * Visit a (kind of) [[Wikiversity:Random|random project]]. * [[Wikiversity:Browse|Browse]] Wikiversity, or visit a portal corresponding to your educational level: [[Portal: Pre-school Education|pre-school]], [[Portal: Primary Education|primary]], [[Portal:Secondary Education|secondary]], [[Portal:Tertiary Education|tertiary]], [[Portal:Non-formal Education|non-formal education]]. * Find out about [[Wikiversity:Research|research]] activities on Wikiversity. * [[Wikiversity:Introduction explore|Explore]] Wikiversity with the links to your left. </div> <!-- The Right column --> <div style="width:50.0%; float:left"> * Enable VisualEditor under [[Special:Preferences#mw-prefsection-betafeatures|Beta]] settings to make article editing easier. * Read an [[Wikiversity:Wikiversity teachers|introduction for teachers]] and find out [[Help:How to write an educational resource|how to write an educational resource]] for Wikiversity. * Give [[Wikiversity:Feedback|feedback]] about your initial observations. * Discuss Wikiversity issues or ask questions at the [[Wikiversity:Colloquium|colloquium]]. * [[Wikiversity:Chat|Chat]] with other Wikiversitans on [[:freenode:wikiversity|<kbd>#wikiversity</kbd>]]. </div> <br clear="both"/> You do not need to be an educator to edit. You only need to [[Wikiversity:Be bold|be bold]] to contribute and to experiment with the [[wikiversity:sandbox|sandbox]] or [[special:mypage|your userpage]]. See you around Wikiversity! --[[User:Dave Braunschweig|Dave Braunschweig]] ([[User talk:Dave Braunschweig|discuss]] • [[Special:Contributions/Dave Braunschweig|contribs]]) 14:42, 12 August 2022 (UTC)</div> <!-- Template:Welcome --> {{Robelbox/close}} gir2ccqw2jeph58jl16h6sqh3z8pbus 2 286310 2413972 2022-08-12T14:52:26Z AliGhasemi 288579 New resource with "<div align="center"> {| class="wikitable" |+ |- |{{Userbox | border-c = #fff | id = PROG | id-c = #9f0 | id-fc = #000 | id-s = 14 | info = This user is an expert in '''[[Computer programming|Programming]]'''. | info-c = #cf9 | info-fc = #000 | info-s = 8 }} |{{userbox | id = [[Image:Nuvola apps konsole.png|45px]] | info = This user is able to write [[computer program]]s. }} |- |{{userbox | border-c = {{{border-c|black}}} | id = Image:..." wikitext text/x-wiki <div align="center"> {| class="wikitable" |+ |- |{{Userbox | border-c = #fff | id = PROG | id-c = #9f0 | id-fc = #000 | id-s = 14 | info = This user is an expert in '''[[Computer programming|Programming]]'''. | info-c = #cf9 | info-fc = #000 | info-s = 8 }} |{{userbox | id = [[Image:Nuvola apps konsole.png|45px]] | info = This user is able to write [[computer program]]s. }} |- |{{userbox | border-c = {{{border-c|black}}} | id = [[Image:{{{id|The Ankh.jpg}}}|50x50px]] | id-c ={{{id-c|#000000}}} | info = {{{info|This user is interested in [[ancient history|ancient civilizations]].}}} | info-c = {{{info-c|#f6f6f6}}} | usercategory = <includeonly>Wikipedians interested in ancient history</includeonly> }} |{{userbox-level|level=|id=Art|id-s=12|info=This user is an '''[[Art|Artist]]'''. This user creates.}} |- |{{userbox | border-c = slategray | id = [[Image:Ezra Cornell's first book.jpg|45px]] | id-c = slategray | info = This user is interested in '''[[linguistics]]'''. | info-c = #FAFA00 | info-fc = {{{info-fc|black}}} | info-s = {{{info-s|8}}} | usercategory = <includeonly>Wikipedians interested in linguistics</includeonly> | nocat = {{{nocat|}}} }} |{{userbox | id = [[File:Ezra Cornell's first book.jpg|x45px]] | info = This user is interested in '''[[literature]]'''. | usercategory = <includeonly>Wikipedians interested in literature</includeonly> }} |} </div> <div align="center"> {| class="wikitable" style="text-align:center" |+[[File:Wikipedia-logo-fa.png|29x29px]] Wikipedia Statistics ![[File:User.gif]] Number of Users ![[File:Article_green.png|33x33px]] Number of Articles ![[File:Icons-mini-image.gif]] Number of Files ![[File:Admin_Puzzle_Icon.png|27x27px]] Number of Admins |- |{{NUMBEROFUSERS}} |{{NUMBEROFARTICLES}} |{{NUMBEROFFILES}} |{{NUMBEROFADMINS}} |} </div> qibagqjqdn2d9t0pe8pz64a5fk4rttm 3 286311 2413973 2022-08-12T14:53:30Z Dave Braunschweig 426084 Welcome wikitext text/x-wiki {{Robelbox|theme=9|title=Welcome!|width=100%}} <div style="{{Robelbox/pad}}"> '''Hello and [[Wikiversity:Welcome|Welcome]] to [[Wikiversity:What is Wikiversity|Wikiversity]] Btarmstrong24!''' You can [[Wikiversity:Contact|contact us]] with [[Wikiversity:Questions|questions]] at the [[Wikiversity:Colloquium|colloquium]] or [[User talk:Dave Braunschweig|me personally]] when you need [[Help:Contents|help]]. Please remember to [[Wikiversity:Signature|sign and date]] your finished comments when [[Wikiversity:Who are Wikiversity participants?|participating]] in [[Wikiversity:Talk page|discussions]]. The signature icon [[File:OOjs UI icon signature-ltr.svg]] above the edit window makes it simple. All users are expected to abide by our [[Wikiversity:Privacy policy|Privacy]], [[Wikiversity:Civility|Civility]], and the [[Foundation:Terms of Use|Terms of Use]] policies while at Wikiversity. To [[Wikiversity:Introduction|get started]], you may <!-- The Left column --> <div style="width:50.0%; float:left"> * [[Help:guides|Take a guided tour]] and learn [[Help:Editing|to edit]]. * Visit a (kind of) [[Wikiversity:Random|random project]]. * [[Wikiversity:Browse|Browse]] Wikiversity, or visit a portal corresponding to your educational level: [[Portal: Pre-school Education|pre-school]], [[Portal: Primary Education|primary]], [[Portal:Secondary Education|secondary]], [[Portal:Tertiary Education|tertiary]], [[Portal:Non-formal Education|non-formal education]]. * Find out about [[Wikiversity:Research|research]] activities on Wikiversity. * [[Wikiversity:Introduction explore|Explore]] Wikiversity with the links to your left. </div> <!-- The Right column --> <div style="width:50.0%; float:left"> * Enable VisualEditor under [[Special:Preferences#mw-prefsection-betafeatures|Beta]] settings to make article editing easier. * Read an [[Wikiversity:Wikiversity teachers|introduction for teachers]] and find out [[Help:How to write an educational resource|how to write an educational resource]] for Wikiversity. * Give [[Wikiversity:Feedback|feedback]] about your initial observations. * Discuss Wikiversity issues or ask questions at the [[Wikiversity:Colloquium|colloquium]]. * [[Wikiversity:Chat|Chat]] with other Wikiversitans on [[:freenode:wikiversity|<kbd>#wikiversity</kbd>]]. </div> <br clear="both"/> You do not need to be an educator to edit. You only need to [[Wikiversity:Be bold|be bold]] to contribute and to experiment with the [[wikiversity:sandbox|sandbox]] or [[special:mypage|your userpage]]. See you around Wikiversity! --[[User:Dave Braunschweig|Dave Braunschweig]] ([[User talk:Dave Braunschweig|discuss]] • [[Special:Contributions/Dave Braunschweig|contribs]]) 14:53, 12 August 2022 (UTC)</div> <!-- Template:Welcome --> {{Robelbox/close}} paxyt0v7pl7f4wulq8lqya5dj10dexk 3 286312 2413974 2022-08-12T14:53:31Z Dave Braunschweig 426084 Welcome wikitext text/x-wiki {{Robelbox|theme=9|title=Welcome!|width=100%}} <div style="{{Robelbox/pad}}"> '''Hello and [[Wikiversity:Welcome|Welcome]] to [[Wikiversity:What is Wikiversity|Wikiversity]] Ibm4444!''' You can [[Wikiversity:Contact|contact us]] with [[Wikiversity:Questions|questions]] at the [[Wikiversity:Colloquium|colloquium]] or [[User talk:Dave Braunschweig|me personally]] when you need [[Help:Contents|help]]. Please remember to [[Wikiversity:Signature|sign and date]] your finished comments when [[Wikiversity:Who are Wikiversity participants?|participating]] in [[Wikiversity:Talk page|discussions]]. The signature icon [[File:OOjs UI icon signature-ltr.svg]] above the edit window makes it simple. All users are expected to abide by our [[Wikiversity:Privacy policy|Privacy]], [[Wikiversity:Civility|Civility]], and the [[Foundation:Terms of Use|Terms of Use]] policies while at Wikiversity. To [[Wikiversity:Introduction|get started]], you may <!-- The Left column --> <div style="width:50.0%; float:left"> * [[Help:guides|Take a guided tour]] and learn [[Help:Editing|to edit]]. * Visit a (kind of) [[Wikiversity:Random|random project]]. * [[Wikiversity:Browse|Browse]] Wikiversity, or visit a portal corresponding to your educational level: [[Portal: Pre-school Education|pre-school]], [[Portal: Primary Education|primary]], [[Portal:Secondary Education|secondary]], [[Portal:Tertiary Education|tertiary]], [[Portal:Non-formal Education|non-formal education]]. * Find out about [[Wikiversity:Research|research]] activities on Wikiversity. * [[Wikiversity:Introduction explore|Explore]] Wikiversity with the links to your left. </div> <!-- The Right column --> <div style="width:50.0%; float:left"> * Enable VisualEditor under [[Special:Preferences#mw-prefsection-betafeatures|Beta]] settings to make article editing easier. * Read an [[Wikiversity:Wikiversity teachers|introduction for teachers]] and find out [[Help:How to write an educational resource|how to write an educational resource]] for Wikiversity. * Give [[Wikiversity:Feedback|feedback]] about your initial observations. * Discuss Wikiversity issues or ask questions at the [[Wikiversity:Colloquium|colloquium]]. * [[Wikiversity:Chat|Chat]] with other Wikiversitans on [[:freenode:wikiversity|<kbd>#wikiversity</kbd>]]. </div> <br clear="both"/> You do not need to be an educator to edit. You only need to [[Wikiversity:Be bold|be bold]] to contribute and to experiment with the [[wikiversity:sandbox|sandbox]] or [[special:mypage|your userpage]]. See you around Wikiversity! --[[User:Dave Braunschweig|Dave Braunschweig]] ([[User talk:Dave Braunschweig|discuss]] • [[Special:Contributions/Dave Braunschweig|contribs]]) 14:53, 12 August 2022 (UTC)</div> <!-- Template:Welcome --> {{Robelbox/close}} 0zn44dxrcvldpdxtgyxv6ajakzu82hr 3 286313 2413975 2022-08-12T14:53:31Z Dave Braunschweig 426084 Welcome wikitext text/x-wiki {{Robelbox|theme=9|title=Welcome!|width=100%}} <div style="{{Robelbox/pad}}"> '''Hello and [[Wikiversity:Welcome|Welcome]] to [[Wikiversity:What is Wikiversity|Wikiversity]] BenjiD&#39;Ange!''' You can [[Wikiversity:Contact|contact us]] with [[Wikiversity:Questions|questions]] at the [[Wikiversity:Colloquium|colloquium]] or [[User talk:Dave Braunschweig|me personally]] when you need [[Help:Contents|help]]. Please remember to [[Wikiversity:Signature|sign and date]] your finished comments when [[Wikiversity:Who are Wikiversity participants?|participating]] in [[Wikiversity:Talk page|discussions]]. The signature icon [[File:OOjs UI icon signature-ltr.svg]] above the edit window makes it simple. All users are expected to abide by our [[Wikiversity:Privacy policy|Privacy]], [[Wikiversity:Civility|Civility]], and the [[Foundation:Terms of Use|Terms of Use]] policies while at Wikiversity. To [[Wikiversity:Introduction|get started]], you may <!-- The Left column --> <div style="width:50.0%; float:left"> * [[Help:guides|Take a guided tour]] and learn [[Help:Editing|to edit]]. * Visit a (kind of) [[Wikiversity:Random|random project]]. * [[Wikiversity:Browse|Browse]] Wikiversity, or visit a portal corresponding to your educational level: [[Portal: Pre-school Education|pre-school]], [[Portal: Primary Education|primary]], [[Portal:Secondary Education|secondary]], [[Portal:Tertiary Education|tertiary]], [[Portal:Non-formal Education|non-formal education]]. * Find out about [[Wikiversity:Research|research]] activities on Wikiversity. * [[Wikiversity:Introduction explore|Explore]] Wikiversity with the links to your left. </div> <!-- The Right column --> <div style="width:50.0%; float:left"> * Enable VisualEditor under [[Special:Preferences#mw-prefsection-betafeatures|Beta]] settings to make article editing easier. * Read an [[Wikiversity:Wikiversity teachers|introduction for teachers]] and find out [[Help:How to write an educational resource|how to write an educational resource]] for Wikiversity. * Give [[Wikiversity:Feedback|feedback]] about your initial observations. * Discuss Wikiversity issues or ask questions at the [[Wikiversity:Colloquium|colloquium]]. * [[Wikiversity:Chat|Chat]] with other Wikiversitans on [[:freenode:wikiversity|<kbd>#wikiversity</kbd>]]. </div> <br clear="both"/> You do not need to be an educator to edit. You only need to [[Wikiversity:Be bold|be bold]] to contribute and to experiment with the [[wikiversity:sandbox|sandbox]] or [[special:mypage|your userpage]]. See you around Wikiversity! --[[User:Dave Braunschweig|Dave Braunschweig]] ([[User talk:Dave Braunschweig|discuss]] • [[Special:Contributions/Dave Braunschweig|contribs]]) 14:53, 12 August 2022 (UTC)</div> <!-- Template:Welcome --> {{Robelbox/close}} dcxq5kl414nkn3fk7ojv9arqiwcwn0k 3 286314 2413976 2022-08-12T14:53:31Z Dave Braunschweig 426084 Welcome wikitext text/x-wiki {{Robelbox|theme=9|title=Welcome!|width=100%}} <div style="{{Robelbox/pad}}"> '''Hello and [[Wikiversity:Welcome|Welcome]] to [[Wikiversity:What is Wikiversity|Wikiversity]] U3246554!''' You can [[Wikiversity:Contact|contact us]] with [[Wikiversity:Questions|questions]] at the [[Wikiversity:Colloquium|colloquium]] or [[User talk:Dave Braunschweig|me personally]] when you need [[Help:Contents|help]]. Please remember to [[Wikiversity:Signature|sign and date]] your finished comments when [[Wikiversity:Who are Wikiversity participants?|participating]] in [[Wikiversity:Talk page|discussions]]. The signature icon [[File:OOjs UI icon signature-ltr.svg]] above the edit window makes it simple. All users are expected to abide by our [[Wikiversity:Privacy policy|Privacy]], [[Wikiversity:Civility|Civility]], and the [[Foundation:Terms of Use|Terms of Use]] policies while at Wikiversity. To [[Wikiversity:Introduction|get started]], you may <!-- The Left column --> <div style="width:50.0%; float:left"> * [[Help:guides|Take a guided tour]] and learn [[Help:Editing|to edit]]. * Visit a (kind of) [[Wikiversity:Random|random project]]. * [[Wikiversity:Browse|Browse]] Wikiversity, or visit a portal corresponding to your educational level: [[Portal: Pre-school Education|pre-school]], [[Portal: Primary Education|primary]], [[Portal:Secondary Education|secondary]], [[Portal:Tertiary Education|tertiary]], [[Portal:Non-formal Education|non-formal education]]. * Find out about [[Wikiversity:Research|research]] activities on Wikiversity. * [[Wikiversity:Introduction explore|Explore]] Wikiversity with the links to your left. </div> <!-- The Right column --> <div style="width:50.0%; float:left"> * Enable VisualEditor under [[Special:Preferences#mw-prefsection-betafeatures|Beta]] settings to make article editing easier. * Read an [[Wikiversity:Wikiversity teachers|introduction for teachers]] and find out [[Help:How to write an educational resource|how to write an educational resource]] for Wikiversity. * Give [[Wikiversity:Feedback|feedback]] about your initial observations. * Discuss Wikiversity issues or ask questions at the [[Wikiversity:Colloquium|colloquium]]. * [[Wikiversity:Chat|Chat]] with other Wikiversitans on [[:freenode:wikiversity|<kbd>#wikiversity</kbd>]]. </div> <br clear="both"/> You do not need to be an educator to edit. You only need to [[Wikiversity:Be bold|be bold]] to contribute and to experiment with the [[wikiversity:sandbox|sandbox]] or [[special:mypage|your userpage]]. See you around Wikiversity! --[[User:Dave Braunschweig|Dave Braunschweig]] ([[User talk:Dave Braunschweig|discuss]] • [[Special:Contributions/Dave Braunschweig|contribs]]) 14:53, 12 August 2022 (UTC)</div> <!-- Template:Welcome --> {{Robelbox/close}} f64x0r2jxqkub0efh62r35kqhyh1e9s 3 286315 2413977 2022-08-12T14:55:02Z Dave Braunschweig 426084 Welcome wikitext text/x-wiki {{Robelbox|theme=9|title=Welcome!|width=100%}} <div style="{{Robelbox/pad}}"> '''Hello and [[Wikiversity:Welcome|Welcome]] to [[Wikiversity:What is Wikiversity|Wikiversity]] Rhythmicblueberry!''' You can [[Wikiversity:Contact|contact us]] with [[Wikiversity:Questions|questions]] at the [[Wikiversity:Colloquium|colloquium]] or [[User talk:Dave Braunschweig|me personally]] when you need [[Help:Contents|help]]. Please remember to [[Wikiversity:Signature|sign and date]] your finished comments when [[Wikiversity:Who are Wikiversity participants?|participating]] in [[Wikiversity:Talk page|discussions]]. The signature icon [[File:OOjs UI icon signature-ltr.svg]] above the edit window makes it simple. All users are expected to abide by our [[Wikiversity:Privacy policy|Privacy]], [[Wikiversity:Civility|Civility]], and the [[Foundation:Terms of Use|Terms of Use]] policies while at Wikiversity. To [[Wikiversity:Introduction|get started]], you may <!-- The Left column --> <div style="width:50.0%; float:left"> * [[Help:guides|Take a guided tour]] and learn [[Help:Editing|to edit]]. * Visit a (kind of) [[Wikiversity:Random|random project]]. * [[Wikiversity:Browse|Browse]] Wikiversity, or visit a portal corresponding to your educational level: [[Portal: Pre-school Education|pre-school]], [[Portal: Primary Education|primary]], [[Portal:Secondary Education|secondary]], [[Portal:Tertiary Education|tertiary]], [[Portal:Non-formal Education|non-formal education]]. * Find out about [[Wikiversity:Research|research]] activities on Wikiversity. * [[Wikiversity:Introduction explore|Explore]] Wikiversity with the links to your left. </div> <!-- The Right column --> <div style="width:50.0%; float:left"> * Enable VisualEditor under [[Special:Preferences#mw-prefsection-betafeatures|Beta]] settings to make article editing easier. * Read an [[Wikiversity:Wikiversity teachers|introduction for teachers]] and find out [[Help:How to write an educational resource|how to write an educational resource]] for Wikiversity. * Give [[Wikiversity:Feedback|feedback]] about your initial observations. * Discuss Wikiversity issues or ask questions at the [[Wikiversity:Colloquium|colloquium]]. * [[Wikiversity:Chat|Chat]] with other Wikiversitans on [[:freenode:wikiversity|<kbd>#wikiversity</kbd>]]. </div> <br clear="both"/> You do not need to be an educator to edit. You only need to [[Wikiversity:Be bold|be bold]] to contribute and to experiment with the [[wikiversity:sandbox|sandbox]] or [[special:mypage|your userpage]]. See you around Wikiversity! --[[User:Dave Braunschweig|Dave Braunschweig]] ([[User talk:Dave Braunschweig|discuss]] • [[Special:Contributions/Dave Braunschweig|contribs]]) 14:55, 12 August 2022 (UTC)</div> <!-- Template:Welcome --> {{Robelbox/close}} es0z9og30l2gzvd2mzbwwaw7ty8d7dq 3 286316 2413998 2022-08-12T18:59:30Z Dave Braunschweig 426084 Welcome wikitext text/x-wiki {{Robelbox|theme=9|title=Welcome!|width=100%}} <div style="{{Robelbox/pad}}"> '''Hello and [[Wikiversity:Welcome|Welcome]] to [[Wikiversity:What is Wikiversity|Wikiversity]] AliGhasemi!''' You can [[Wikiversity:Contact|contact us]] with [[Wikiversity:Questions|questions]] at the [[Wikiversity:Colloquium|colloquium]] or [[User talk:Dave Braunschweig|me personally]] when you need [[Help:Contents|help]]. Please remember to [[Wikiversity:Signature|sign and date]] your finished comments when [[Wikiversity:Who are Wikiversity participants?|participating]] in [[Wikiversity:Talk page|discussions]]. The signature icon [[File:OOjs UI icon signature-ltr.svg]] above the edit window makes it simple. All users are expected to abide by our [[Wikiversity:Privacy policy|Privacy]], [[Wikiversity:Civility|Civility]], and the [[Foundation:Terms of Use|Terms of Use]] policies while at Wikiversity. To [[Wikiversity:Introduction|get started]], you may <!-- The Left column --> <div style="width:50.0%; float:left"> * [[Help:guides|Take a guided tour]] and learn [[Help:Editing|to edit]]. * Visit a (kind of) [[Wikiversity:Random|random project]]. * [[Wikiversity:Browse|Browse]] Wikiversity, or visit a portal corresponding to your educational level: [[Portal: Pre-school Education|pre-school]], [[Portal: Primary Education|primary]], [[Portal:Secondary Education|secondary]], [[Portal:Tertiary Education|tertiary]], [[Portal:Non-formal Education|non-formal education]]. * Find out about [[Wikiversity:Research|research]] activities on Wikiversity. * [[Wikiversity:Introduction explore|Explore]] Wikiversity with the links to your left. </div> <!-- The Right column --> <div style="width:50.0%; float:left"> * Enable VisualEditor under [[Special:Preferences#mw-prefsection-betafeatures|Beta]] settings to make article editing easier. * Read an [[Wikiversity:Wikiversity teachers|introduction for teachers]] and find out [[Help:How to write an educational resource|how to write an educational resource]] for Wikiversity. * Give [[Wikiversity:Feedback|feedback]] about your initial observations. * Discuss Wikiversity issues or ask questions at the [[Wikiversity:Colloquium|colloquium]]. * [[Wikiversity:Chat|Chat]] with other Wikiversitans on [[:freenode:wikiversity|<kbd>#wikiversity</kbd>]]. </div> <br clear="both"/> You do not need to be an educator to edit. You only need to [[Wikiversity:Be bold|be bold]] to contribute and to experiment with the [[wikiversity:sandbox|sandbox]] or [[special:mypage|your userpage]]. See you around Wikiversity! --[[User:Dave Braunschweig|Dave Braunschweig]] ([[User talk:Dave Braunschweig|discuss]] • [[Special:Contributions/Dave Braunschweig|contribs]]) 18:59, 12 August 2022 (UTC)</div> <!-- Template:Welcome --> {{Robelbox/close}} hd48cfgy49uxktydov3lth1msk8vfro 0 286317 2414018 2022-08-13T03:08:58Z Jdebear 2948147 New resource with "=== Placeholder Title === === Placeholder Title === === Placeholder Title === === Placeholder Title ===" wikitext text/x-wiki === Placeholder Title === === Placeholder Title === === Placeholder Title === === Placeholder Title === 9bnt2233v1ix06yvumsh9451ccmwpep 2 286318 2414020 2022-08-13T03:10:36Z Jdebear 2948147 New resource with "=== Placeholder ===" wikitext text/x-wiki === Placeholder === b3euywtngunyzs4s4so09gfgnv5ts86 6 286319 2414021 2022-08-13T04:06:44Z Marshallsumter 311529 {{Information1 |Description = The FOXSI-2 sounding rocket is shown on the launch pad. |Source = The image appears on a website entitled, "File:FOXSI-2 sounding rocket.jpg" at https://en.wikipedia.org/wiki/File:FOXSI-2_sounding_rocket.jpg. |Date = 25 April 2015 |Author = NASA, Säm Krucker, UC Berkeley |Rationale = No free licensed or public domain alternatives known to exist to show a photograph of the FOXSI team in front of the FOXSI-2 sounding rocket on the launch pad. |Permission = Fair Use... wikitext text/x-wiki == Summary == {{Information1 |Description = The FOXSI-2 sounding rocket is shown on the launch pad. |Source = The image appears on a website entitled, "File:FOXSI-2 sounding rocket.jpg" at https://en.wikipedia.org/wiki/File:FOXSI-2_sounding_rocket.jpg. |Date = 25 April 2015 |Author = NASA, Säm Krucker, UC Berkeley |Rationale = No free licensed or public domain alternatives known to exist to show a photograph of the FOXSI team in front of the FOXSI-2 sounding rocket on the launch pad. |Permission = Fair Use, NASA images are usually Public Domain but Säm Krucker, UC Berkeley, may not have agreed to this. The image has not been transferred to Commons perhaps because of the above. }} {{Fairuse}} [[Category:Sounding rocket images]] e7x8cos2a915uu94v4b6n2289dfdha4 6 286320 2414022 2022-08-13T04:13:57Z Marshallsumter 311529 {{Information1 |Description = A high resolution render shows the FOXSI-2 payload. |Source = The image appears on a website entitled, "File:FOXSI-2 Sounding Rocket Payload.png" at https://en.wikipedia.org/wiki/File:FOXSI-2_Sounding_Rocket_Payload.png. |Date = 1 January 2015 |Author = [[c:User:Schriste|Schriste]] |Rationale = No free licensed or public domain alternatives known to exist to show a high resolution render of the FOXSI-2 payload. |Permission = Fair Use }} {{Fairuse}} [[Category:X-... wikitext text/x-wiki == Summary == {{Information1 |Description = A high resolution render shows the FOXSI-2 payload. |Source = The image appears on a website entitled, "File:FOXSI-2 Sounding Rocket Payload.png" at https://en.wikipedia.org/wiki/File:FOXSI-2_Sounding_Rocket_Payload.png. |Date = 1 January 2015 |Author = [[c:User:Schriste|Schriste]] |Rationale = No free licensed or public domain alternatives known to exist to show a high resolution render of the FOXSI-2 payload. |Permission = Fair Use }} {{Fairuse}} [[Category:X-ray astronomy images]] ke26zso70neg6af13nxx2vdajds1ckm 2414023 2414022 2022-08-13T04:14:23Z Marshallsumter 311529 /* Summary */ wikitext text/x-wiki == Summary == {{Information1 |Description = A high resolution render shows the FOXSI-2 payload. |Source = The image appears on a website entitled, "File:FOXSI-2 Sounding Rocket Payload.png" at https://en.wikipedia.org/wiki/File:FOXSI-2_Sounding_Rocket_Payload.png. |Date = 1 January 2015 |Author = [[w:User:Schriste|Schriste]] |Rationale = No free licensed or public domain alternatives known to exist to show a high resolution render of the FOXSI-2 payload. |Permission = Fair Use }} {{Fairuse}} [[Category:X-ray astronomy images]] qovk0rijfonaaqodoj32rc6e70u86kv 0 286321 2414041 2022-08-13T06:57:52Z U3203545 2947578 Template wikitext text/x-wiki {{title|Chapter title:<br>Subtitle?}} {{MECR3|1=https://yourlinkgoeshere.com}} __TOC__ ==Overview== You are underway {{smile}}! This template provides tips for [[Motivation and emotion/Assessment/Topic|topic development]]. Gradually remove these suggestions as you develop the chapter. Also consult the [[Motivation and emotion/Assessment/Chapter|author guidelines]]. At the top of the chapter, the title and sub-title should match the ''exact'' wording and casing as shown in the {{Motivation and emotion/Book}}. The sub-titles all end with a question mark. This Overview section should be concise but consist of several paragraphs which engage the reader, illustrate the problem, and outline how psychological science can help. {{RoundBoxTop|theme=3}} '''Focus questions:''' * What is the first focus question? * What is the second focus question? * What is the third focus question? {{RoundBoxBottom}} {{tip| Suggestions for this section: * What is the problem? Why is it important? * How can specific motivation and/or emotion theories and research help? * Provide an example or case study. * Conclude with Focus questions to guide the chapter. }} ==Main headings== How you are going to structure the chapter? Aim for three to six main headings between the [[#Overview|Overview]] and [[#Conclusion|Conclusion]]. {{tip|Suggestions for this section: * For the [[Motivation and emotion/Assessment/Topic|topic development]], provide at least 3 bullet-points about key content per section. Include key citations. * For the [[Motivation and emotion/Assessment/Chapter|book chapter]], expand the bullet points into paragraphs. * If a section has a lot of content, arrange it into two to five sub-headings such as in the [[#Interactive learning features|interactive learning features section]]. Avoid having sections with only one sub-heading. }} ==Learning features== What brings an online book chapter to life are its interactive learning features. Case studies, feature boxes, figures, links, tables, and quiz questions can be used throughout the chapter. ===Case studies=== Case studies describe real-world examples of concepts in action. Case studies can be real or fictional. A case could be used multiple times during a chapter to illustrate different theories or stages. It is often helpful to present case studies using [[#Feature boxes|feature boxes]]. ===Boxes=== Boxes can be used to highlight content, but don't overuse them. There are many different ways of creating boxes (e.g., see [[Help:Pretty boxes|Pretty boxes]]). Possible uses include: * Focus questions * Case studies or examples * Quiz questions * Take-home messages {{RoundBoxTop|theme=3}} ;Feature box example * Shaded background * Coloured border {{RoundBoxBottom}} ===Figures=== [[File:Monkey-typing.jpg|right|205px|thumb|''Figure 1''. Example image with descriptive caption.]] Use figures to illustrate concepts, add interest, and provide examples. Figures can be used to show photographs, drawings, diagrams, graphs, etcetera. Figures can be embedded throughout the chapter, starting with the Overview section. Figures should be captioned (using a number and a description) in order to explain their relevance to the text. Possible images can be found at [[commons:|Wikimedia Commons]]. Images can also be uploaded if they are licensed for re-use or if you created the image. Each figure should be referred to at least once in the main text (e.g., see Figure 1). ===Links=== Where key words are first used, make them into [[Help:Links|interwiki links]] such as Wikipedia links to articles about famous people (e.g., [[w:Sigmund Freud|Sigmund Freud]] and key concepts (e.g., [[w:Dreams|dreams]]) and links to book chapters about related topics (e.g., would you like to learn about how to overcome [[Motivation and emotion/Book/2020/Writer's block|writer's block]]?). ===Tables=== Tables can be an effective way to organise and summarise information. Tables should be captioned (using APA style) to explain their relevance to the text. Plus each table should be referred to at least once in the main text (e.g., see Table 1 and Table 2). Here are some [[Motivation and emotion/Wikiversity/Tables|example 3 x 3 tables]] which could be adapted. ===Quizzes=== Quizzes are a direct way to engage readers. But don't make quizzes too hard or long. It is better to have one or two review questions per major section than a long quiz at the end. Try to quiz conceptual understanding, rather than trivia. Here are some simple quiz questions which could be adapted. Choose the correct answers and click "Submit": <quiz display=simple> {Quizzes are an interactive learning feature: |type="()"} + True - False {Long quizzes are a good idea: |type="()"} - True + False </quiz> To learn about different types of quiz questions, see [[Help:Quiz|Quiz]]. ==Conclusion== The Conclusion is arguably the most important section. It should be possible for someone to read the [[#Overview|Overview]] and the Conclusion and still get a good idea of the topic. {{tip|Suggestions for this section: * What is the answer to the question in the sub-title (based on psychological theory and research)? * What are the answers to the focus questions? * What are the practical, take-home messages? }} ==See also== Provide up to half-a-dozen [[Help:Contents/Links#Interwiki_links|internal (wiki) links]] to relevant Wikiversity pages (esp. related [[Motivation and emotion/Book|motivation and emotion book chapters]]) and [[w:|Wikipedia articles]]. For example: * [[Motivation and emotion/Book/2016/Anorexia nervosa and extrinsic motivation|Anorexia nervosa and extrinsic motivation]] (Book chapter, 2016) * [[w:David McClelland|David McClelland]] (Wikipedia) * [[Motivation and emotion/Book/2018/Loss aversion|Loss aversion]] (Book chapter, 2018) * [[w:Maslow's hierarchy of needs|Maslow's hierarchy of needs]] (Wikipedia) {{tip|Suggestions for this section: * Present in alphabetical order. * Include the source in parentheses. }} ==References== List the cited references in [[w:APA style|APA style]] (7th ed.) or [[w:Wikipedia:Citing sources|wiki style]]. APA style example: {{Hanging indent|1= Blair, R. J. R. (2004). The roles of orbital frontal cortex in the modulation of antisocial behavior. ''Brain and Cognition'', ''55''(1), 198–208. https://doi.org/10.1016/S0278-2626(03)00276-8 Buckholtz, J. W., & Meyer-Lindenberg, A. (2008). MAOA and the neurogenetic architecture of human aggression. ''Trends in Neurosciences'', ''31''(3), 120–129. https://doi.org/10.1016/j.tins.2007.12.006 Eckardt, M., File, S., Gessa, G., Grant, K., Guerri, C., Hoffman, P., & Tabakoff, B. (1998). Effects of moderate alcohol consumption on the central nervous system. ''Alcoholism, Clinical and Experimental Research'', ''22''(5), 998–1040. https://doi.org/10.1111/j.1530-0277.1998.tb03695.x }} {{tip|Suggestions for this section: * Important aspects for APA style include: ** Wrap the set of references in the hanging indent template. Using "Edit source": <nowiki>{{Hanging indent|1= the full list of references}}</nowiki> ** Author surname, followed by a comma, then author initials separated by full stops and spaces ** Year of publication in parentheses ** Title of work in lower case except first letter and proper names, ending in a full-stop. ** Journal title in italics, volume number in italics, issue number in parentheses, first and last page numbers separated by an en-dash(–), followed by a full-stop. ** Provide the full doi as a URL and working hyperlink * Common mistakes include: ** incorrect capitalisation ** incorrect italicisation ** providing a "retrieved from" date (not part of APA 7th ed. style). ** citing sources that weren't actually read or consulted }} ==External links== Provide up to half-a-dozen [[Help:Contents/Links#External_links|external links]] to relevant resources such as presentations, news articles, and professional sites. For example: * [https://students.unimelb.edu.au/academic-skills/explore-our-resources/essay-writing/six-top-tips-for-writing-a-great-essay Six top tips for writing a great essay] (University of Melbourne) * [http://www.skillsyouneed.com/write/structure.html The importance of structure] (skillsyouneed.com) {{tip|Suggestions for this section: * Only select links to major external resources about the topic * Present in alphabetical order * Include the source in parentheses after the link }} [[Category:{{#titleparts:{{PAGENAME}}|3}}]] thp5r91aziue2l80cis4wxipwwn2uzy 2414042 2414041 2022-08-13T07:02:02Z U3203545 2947578 Template wikitext text/x-wiki {{title|Compassion:<br>What is compassion, what are its pros and cons, and how can it be fostered?}} {{MECR3|1=https://yourlinkgoeshere.com}} __TOC__ ==Overview== You are underway {{smile}}! This template provides tips for [[Motivation and emotion/Assessment/Topic|topic development]]. Gradually remove these suggestions as you develop the chapter. Also consult the [[Motivation and emotion/Assessment/Chapter|author guidelines]]. At the top of the chapter, the title and sub-title should match the ''exact'' wording and casing as shown in the {{Motivation and emotion/Book}}. The sub-titles all end with a question mark. This Overview section should be concise but consist of several paragraphs which engage the reader, illustrate the problem, and outline how psychological science can help. {{RoundBoxTop|theme=3}} '''Focus questions:''' * What is the first focus question? * What is the second focus question? * What is the third focus question? {{RoundBoxBottom}} {{tip| Suggestions for this section: * What is the problem? Why is it important? * How can specific motivation and/or emotion theories and research help? * Provide an example or case study. * Conclude with Focus questions to guide the chapter. }} ==Main headings== How you are going to structure the chapter? Aim for three to six main headings between the [[#Overview|Overview]] and [[#Conclusion|Conclusion]]. {{tip|Suggestions for this section: * For the [[Motivation and emotion/Assessment/Topic|topic development]], provide at least 3 bullet-points about key content per section. Include key citations. * For the [[Motivation and emotion/Assessment/Chapter|book chapter]], expand the bullet points into paragraphs. * If a section has a lot of content, arrange it into two to five sub-headings such as in the [[#Interactive learning features|interactive learning features section]]. Avoid having sections with only one sub-heading. }} ==Learning features== What brings an online book chapter to life are its interactive learning features. Case studies, feature boxes, figures, links, tables, and quiz questions can be used throughout the chapter. ===Case studies=== Case studies describe real-world examples of concepts in action. Case studies can be real or fictional. A case could be used multiple times during a chapter to illustrate different theories or stages. It is often helpful to present case studies using [[#Feature boxes|feature boxes]]. ===Boxes=== Boxes can be used to highlight content, but don't overuse them. There are many different ways of creating boxes (e.g., see [[Help:Pretty boxes|Pretty boxes]]). Possible uses include: * Focus questions * Case studies or examples * Quiz questions * Take-home messages {{RoundBoxTop|theme=3}} ;Feature box example * Shaded background * Coloured border {{RoundBoxBottom}} ===Figures=== [[File:Monkey-typing.jpg|right|205px|thumb|''Figure 1''. Example image with descriptive caption.]] Use figures to illustrate concepts, add interest, and provide examples. Figures can be used to show photographs, drawings, diagrams, graphs, etcetera. Figures can be embedded throughout the chapter, starting with the Overview section. Figures should be captioned (using a number and a description) in order to explain their relevance to the text. Possible images can be found at [[commons:|Wikimedia Commons]]. Images can also be uploaded if they are licensed for re-use or if you created the image. Each figure should be referred to at least once in the main text (e.g., see Figure 1). ===Links=== Where key words are first used, make them into [[Help:Links|interwiki links]] such as Wikipedia links to articles about famous people (e.g., [[w:Sigmund Freud|Sigmund Freud]] and key concepts (e.g., [[w:Dreams|dreams]]) and links to book chapters about related topics (e.g., would you like to learn about how to overcome [[Motivation and emotion/Book/2020/Writer's block|writer's block]]?). ===Tables=== Tables can be an effective way to organise and summarise information. Tables should be captioned (using APA style) to explain their relevance to the text. Plus each table should be referred to at least once in the main text (e.g., see Table 1 and Table 2). Here are some [[Motivation and emotion/Wikiversity/Tables|example 3 x 3 tables]] which could be adapted. ===Quizzes=== Quizzes are a direct way to engage readers. But don't make quizzes too hard or long. It is better to have one or two review questions per major section than a long quiz at the end. Try to quiz conceptual understanding, rather than trivia. Here are some simple quiz questions which could be adapted. Choose the correct answers and click "Submit": <quiz display=simple> {Quizzes are an interactive learning feature: |type="()"} + True - False {Long quizzes are a good idea: |type="()"} - True + False </quiz> To learn about different types of quiz questions, see [[Help:Quiz|Quiz]]. ==Conclusion== The Conclusion is arguably the most important section. It should be possible for someone to read the [[#Overview|Overview]] and the Conclusion and still get a good idea of the topic. {{tip|Suggestions for this section: * What is the answer to the question in the sub-title (based on psychological theory and research)? * What are the answers to the focus questions? * What are the practical, take-home messages? }} ==See also== Provide up to half-a-dozen [[Help:Contents/Links#Interwiki_links|internal (wiki) links]] to relevant Wikiversity pages (esp. related [[Motivation and emotion/Book|motivation and emotion book chapters]]) and [[w:|Wikipedia articles]]. For example: * [[Motivation and emotion/Book/2016/Anorexia nervosa and extrinsic motivation|Anorexia nervosa and extrinsic motivation]] (Book chapter, 2016) * [[w:David McClelland|David McClelland]] (Wikipedia) * [[Motivation and emotion/Book/2018/Loss aversion|Loss aversion]] (Book chapter, 2018) * [[w:Maslow's hierarchy of needs|Maslow's hierarchy of needs]] (Wikipedia) {{tip|Suggestions for this section: * Present in alphabetical order. * Include the source in parentheses. }} ==References== List the cited references in [[w:APA style|APA style]] (7th ed.) or [[w:Wikipedia:Citing sources|wiki style]]. APA style example: {{Hanging indent|1= Blair, R. J. R. (2004). The roles of orbital frontal cortex in the modulation of antisocial behavior. ''Brain and Cognition'', ''55''(1), 198–208. https://doi.org/10.1016/S0278-2626(03)00276-8 Buckholtz, J. W., & Meyer-Lindenberg, A. (2008). MAOA and the neurogenetic architecture of human aggression. ''Trends in Neurosciences'', ''31''(3), 120–129. https://doi.org/10.1016/j.tins.2007.12.006 Eckardt, M., File, S., Gessa, G., Grant, K., Guerri, C., Hoffman, P., & Tabakoff, B. (1998). Effects of moderate alcohol consumption on the central nervous system. ''Alcoholism, Clinical and Experimental Research'', ''22''(5), 998–1040. https://doi.org/10.1111/j.1530-0277.1998.tb03695.x }} {{tip|Suggestions for this section: * Important aspects for APA style include: ** Wrap the set of references in the hanging indent template. Using "Edit source": <nowiki>{{Hanging indent|1= the full list of references}}</nowiki> ** Author surname, followed by a comma, then author initials separated by full stops and spaces ** Year of publication in parentheses ** Title of work in lower case except first letter and proper names, ending in a full-stop. ** Journal title in italics, volume number in italics, issue number in parentheses, first and last page numbers separated by an en-dash(–), followed by a full-stop. ** Provide the full doi as a URL and working hyperlink * Common mistakes include: ** incorrect capitalisation ** incorrect italicisation ** providing a "retrieved from" date (not part of APA 7th ed. style). ** citing sources that weren't actually read or consulted }} ==External links== Provide up to half-a-dozen [[Help:Contents/Links#External_links|external links]] to relevant resources such as presentations, news articles, and professional sites. For example: * [https://students.unimelb.edu.au/academic-skills/explore-our-resources/essay-writing/six-top-tips-for-writing-a-great-essay Six top tips for writing a great essay] (University of Melbourne) * [http://www.skillsyouneed.com/write/structure.html The importance of structure] (skillsyouneed.com) {{tip|Suggestions for this section: * Only select links to major external resources about the topic * Present in alphabetical order * Include the source in parentheses after the link }} [[Category:{{#titleparts:{{PAGENAME}}|3}}]] r3lsr60e336ftjyf6t3aqctdy03j9oe 2414043 2414042 2022-08-13T07:23:19Z U3203545 2947578 /* Main headings */ wikitext text/x-wiki {{title|Compassion:<br>What is compassion, what are its pros and cons, and how can it be fostered?}} {{MECR3|1=https://yourlinkgoeshere.com}} __TOC__ ==Overview== You are underway {{smile}}! This template provides tips for [[Motivation and emotion/Assessment/Topic|topic development]]. Gradually remove these suggestions as you develop the chapter. Also consult the [[Motivation and emotion/Assessment/Chapter|author guidelines]]. At the top of the chapter, the title and sub-title should match the ''exact'' wording and casing as shown in the {{Motivation and emotion/Book}}. The sub-titles all end with a question mark. This Overview section should be concise but consist of several paragraphs which engage the reader, illustrate the problem, and outline how psychological science can help. {{RoundBoxTop|theme=3}} '''Focus questions:''' * What is Compassion? * What are the Advantages of Compassion? * What are the Disadvantages of Compassion? * How can we Foster Compassion? {{RoundBoxBottom}} {{tip| Suggestions for this section: * What is the problem? Why is it important? * How can specific motivation and/or emotion theories and research help? * Provide an example or case study. * Conclude with Focus questions to guide the chapter. }} ==What is Compassion?== == What are the Advantages of Compassion? == == What are the Disadvantages of Compassion? == === Compassion Fatigue === == How can we Foster Compassion? == {{tip|Suggestions for this section: * For the [[Motivation and emotion/Assessment/Topic|topic development]], provide at least 3 bullet-points about key content per section. Include key citations. * For the [[Motivation and emotion/Assessment/Chapter|book chapter]], expand the bullet points into paragraphs. * If a section has a lot of content, arrange it into two to five sub-headings such as in the [[#Interactive learning features|interactive learning features section]]. Avoid having sections with only one sub-heading. }} == Learning features == What brings an online book chapter to life are its interactive learning features. Case studies, feature boxes, figures, links, tables, and quiz questions can be used throughout the chapter. ===Case studies=== Case studies describe real-world examples of concepts in action. Case studies can be real or fictional. A case could be used multiple times during a chapter to illustrate different theories or stages. It is often helpful to present case studies using [[#Feature boxes|feature boxes]]. ===Boxes=== Boxes can be used to highlight content, but don't overuse them. There are many different ways of creating boxes (e.g., see [[Help:Pretty boxes|Pretty boxes]]). Possible uses include: * Focus questions * Case studies or examples * Quiz questions * Take-home messages {{RoundBoxTop|theme=3}} ;Feature box example * Shaded background * Coloured border {{RoundBoxBottom}} ===Figures=== [[File:Monkey-typing.jpg|right|205px|thumb|''Figure 1''. Example image with descriptive caption.]] Use figures to illustrate concepts, add interest, and provide examples. Figures can be used to show photographs, drawings, diagrams, graphs, etcetera. Figures can be embedded throughout the chapter, starting with the Overview section. Figures should be captioned (using a number and a description) in order to explain their relevance to the text. Possible images can be found at [[commons:|Wikimedia Commons]]. Images can also be uploaded if they are licensed for re-use or if you created the image. Each figure should be referred to at least once in the main text (e.g., see Figure 1). ===Links=== Where key words are first used, make them into [[Help:Links|interwiki links]] such as Wikipedia links to articles about famous people (e.g., [[w:Sigmund Freud|Sigmund Freud]] and key concepts (e.g., [[w:Dreams|dreams]]) and links to book chapters about related topics (e.g., would you like to learn about how to overcome [[Motivation and emotion/Book/2020/Writer's block|writer's block]]?). ===Tables=== Tables can be an effective way to organise and summarise information. Tables should be captioned (using APA style) to explain their relevance to the text. Plus each table should be referred to at least once in the main text (e.g., see Table 1 and Table 2). Here are some [[Motivation and emotion/Wikiversity/Tables|example 3 x 3 tables]] which could be adapted. ===Quizzes=== Quizzes are a direct way to engage readers. But don't make quizzes too hard or long. It is better to have one or two review questions per major section than a long quiz at the end. Try to quiz conceptual understanding, rather than trivia. Here are some simple quiz questions which could be adapted. Choose the correct answers and click "Submit": <quiz display=simple> {Quizzes are an interactive learning feature: |type="()"} + True - False {Long quizzes are a good idea: |type="()"} - True + False </quiz> To learn about different types of quiz questions, see [[Help:Quiz|Quiz]]. ==Conclusion== The Conclusion is arguably the most important section. It should be possible for someone to read the [[#Overview|Overview]] and the Conclusion and still get a good idea of the topic. {{tip|Suggestions for this section: * What is the answer to the question in the sub-title (based on psychological theory and research)? * What are the answers to the focus questions? * What are the practical, take-home messages? }} ==See also== Provide up to half-a-dozen [[Help:Contents/Links#Interwiki_links|internal (wiki) links]] to relevant Wikiversity pages (esp. related [[Motivation and emotion/Book|motivation and emotion book chapters]]) and [[w:|Wikipedia articles]]. For example: * [[Motivation and emotion/Book/2016/Anorexia nervosa and extrinsic motivation|Anorexia nervosa and extrinsic motivation]] (Book chapter, 2016) * [[w:David McClelland|David McClelland]] (Wikipedia) * [[Motivation and emotion/Book/2018/Loss aversion|Loss aversion]] (Book chapter, 2018) * [[w:Maslow's hierarchy of needs|Maslow's hierarchy of needs]] (Wikipedia) {{tip|Suggestions for this section: * Present in alphabetical order. * Include the source in parentheses. }} ==References== List the cited references in [[w:APA style|APA style]] (7th ed.) or [[w:Wikipedia:Citing sources|wiki style]]. APA style example: {{Hanging indent|1= Blair, R. J. R. (2004). The roles of orbital frontal cortex in the modulation of antisocial behavior. ''Brain and Cognition'', ''55''(1), 198–208. https://doi.org/10.1016/S0278-2626(03)00276-8 Buckholtz, J. W., & Meyer-Lindenberg, A. (2008). MAOA and the neurogenetic architecture of human aggression. ''Trends in Neurosciences'', ''31''(3), 120–129. https://doi.org/10.1016/j.tins.2007.12.006 Eckardt, M., File, S., Gessa, G., Grant, K., Guerri, C., Hoffman, P., & Tabakoff, B. (1998). Effects of moderate alcohol consumption on the central nervous system. ''Alcoholism, Clinical and Experimental Research'', ''22''(5), 998–1040. https://doi.org/10.1111/j.1530-0277.1998.tb03695.x }} {{tip|Suggestions for this section: * Important aspects for APA style include: ** Wrap the set of references in the hanging indent template. Using "Edit source": <nowiki>{{Hanging indent|1= the full list of references}}</nowiki> ** Author surname, followed by a comma, then author initials separated by full stops and spaces ** Year of publication in parentheses ** Title of work in lower case except first letter and proper names, ending in a full-stop. ** Journal title in italics, volume number in italics, issue number in parentheses, first and last page numbers separated by an en-dash(–), followed by a full-stop. ** Provide the full doi as a URL and working hyperlink * Common mistakes include: ** incorrect capitalisation ** incorrect italicisation ** providing a "retrieved from" date (not part of APA 7th ed. style). ** citing sources that weren't actually read or consulted }} ==External links== Provide up to half-a-dozen [[Help:Contents/Links#External_links|external links]] to relevant resources such as presentations, news articles, and professional sites. For example: * [https://students.unimelb.edu.au/academic-skills/explore-our-resources/essay-writing/six-top-tips-for-writing-a-great-essay Six top tips for writing a great essay] (University of Melbourne) * [http://www.skillsyouneed.com/write/structure.html The importance of structure] (skillsyouneed.com) {{tip|Suggestions for this section: * Only select links to major external resources about the topic * Present in alphabetical order * Include the source in parentheses after the link }} [[Category:{{#titleparts:{{PAGENAME}}|3}}]] a4ra2x49jfycagixrxuirbgwhsa3mqe 2414044 2414043 2022-08-13T07:25:37Z U3203545 2947578 /* What is Compassion? */ wikitext text/x-wiki {{title|Compassion:<br>What is compassion, what are its pros and cons, and how can it be fostered?}} {{MECR3|1=https://yourlinkgoeshere.com}} __TOC__ ==Overview== You are underway {{smile}}! This template provides tips for [[Motivation and emotion/Assessment/Topic|topic development]]. Gradually remove these suggestions as you develop the chapter. Also consult the [[Motivation and emotion/Assessment/Chapter|author guidelines]]. At the top of the chapter, the title and sub-title should match the ''exact'' wording and casing as shown in the {{Motivation and emotion/Book}}. The sub-titles all end with a question mark. This Overview section should be concise but consist of several paragraphs which engage the reader, illustrate the problem, and outline how psychological science can help. {{RoundBoxTop|theme=3}} '''Focus questions:''' * What is Compassion? * What are the Advantages of Compassion? * What are the Disadvantages of Compassion? * How can we Foster Compassion? {{RoundBoxBottom}} {{tip| Suggestions for this section: * What is the problem? Why is it important? * How can specific motivation and/or emotion theories and research help? * Provide an example or case study. * Conclude with Focus questions to guide the chapter. }} ==What is Compassion?== === What is the Difference between Compassion and Empathy? === == What are the Advantages of Compassion? == == What are the Disadvantages of Compassion? == === Compassion Fatigue === == How can we Foster Compassion? == {{tip|Suggestions for this section: * For the [[Motivation and emotion/Assessment/Topic|topic development]], provide at least 3 bullet-points about key content per section. Include key citations. * For the [[Motivation and emotion/Assessment/Chapter|book chapter]], expand the bullet points into paragraphs. * If a section has a lot of content, arrange it into two to five sub-headings such as in the [[#Interactive learning features|interactive learning features section]]. Avoid having sections with only one sub-heading. }} == Learning features == What brings an online book chapter to life are its interactive learning features. Case studies, feature boxes, figures, links, tables, and quiz questions can be used throughout the chapter. ===Case studies=== Case studies describe real-world examples of concepts in action. Case studies can be real or fictional. A case could be used multiple times during a chapter to illustrate different theories or stages. It is often helpful to present case studies using [[#Feature boxes|feature boxes]]. ===Boxes=== Boxes can be used to highlight content, but don't overuse them. There are many different ways of creating boxes (e.g., see [[Help:Pretty boxes|Pretty boxes]]). Possible uses include: * Focus questions * Case studies or examples * Quiz questions * Take-home messages {{RoundBoxTop|theme=3}} ;Feature box example * Shaded background * Coloured border {{RoundBoxBottom}} ===Figures=== [[File:Monkey-typing.jpg|right|205px|thumb|''Figure 1''. Example image with descriptive caption.]] Use figures to illustrate concepts, add interest, and provide examples. Figures can be used to show photographs, drawings, diagrams, graphs, etcetera. Figures can be embedded throughout the chapter, starting with the Overview section. Figures should be captioned (using a number and a description) in order to explain their relevance to the text. Possible images can be found at [[commons:|Wikimedia Commons]]. Images can also be uploaded if they are licensed for re-use or if you created the image. Each figure should be referred to at least once in the main text (e.g., see Figure 1). ===Links=== Where key words are first used, make them into [[Help:Links|interwiki links]] such as Wikipedia links to articles about famous people (e.g., [[w:Sigmund Freud|Sigmund Freud]] and key concepts (e.g., [[w:Dreams|dreams]]) and links to book chapters about related topics (e.g., would you like to learn about how to overcome [[Motivation and emotion/Book/2020/Writer's block|writer's block]]?). ===Tables=== Tables can be an effective way to organise and summarise information. Tables should be captioned (using APA style) to explain their relevance to the text. Plus each table should be referred to at least once in the main text (e.g., see Table 1 and Table 2). Here are some [[Motivation and emotion/Wikiversity/Tables|example 3 x 3 tables]] which could be adapted. ===Quizzes=== Quizzes are a direct way to engage readers. But don't make quizzes too hard or long. It is better to have one or two review questions per major section than a long quiz at the end. Try to quiz conceptual understanding, rather than trivia. Here are some simple quiz questions which could be adapted. Choose the correct answers and click "Submit": <quiz display=simple> {Quizzes are an interactive learning feature: |type="()"} + True - False {Long quizzes are a good idea: |type="()"} - True + False </quiz> To learn about different types of quiz questions, see [[Help:Quiz|Quiz]]. ==Conclusion== The Conclusion is arguably the most important section. It should be possible for someone to read the [[#Overview|Overview]] and the Conclusion and still get a good idea of the topic. {{tip|Suggestions for this section: * What is the answer to the question in the sub-title (based on psychological theory and research)? * What are the answers to the focus questions? * What are the practical, take-home messages? }} ==See also== Provide up to half-a-dozen [[Help:Contents/Links#Interwiki_links|internal (wiki) links]] to relevant Wikiversity pages (esp. related [[Motivation and emotion/Book|motivation and emotion book chapters]]) and [[w:|Wikipedia articles]]. For example: * [[Motivation and emotion/Book/2016/Anorexia nervosa and extrinsic motivation|Anorexia nervosa and extrinsic motivation]] (Book chapter, 2016) * [[w:David McClelland|David McClelland]] (Wikipedia) * [[Motivation and emotion/Book/2018/Loss aversion|Loss aversion]] (Book chapter, 2018) * [[w:Maslow's hierarchy of needs|Maslow's hierarchy of needs]] (Wikipedia) {{tip|Suggestions for this section: * Present in alphabetical order. * Include the source in parentheses. }} ==References== List the cited references in [[w:APA style|APA style]] (7th ed.) or [[w:Wikipedia:Citing sources|wiki style]]. APA style example: {{Hanging indent|1= Blair, R. J. R. (2004). The roles of orbital frontal cortex in the modulation of antisocial behavior. ''Brain and Cognition'', ''55''(1), 198–208. https://doi.org/10.1016/S0278-2626(03)00276-8 Buckholtz, J. W., & Meyer-Lindenberg, A. (2008). MAOA and the neurogenetic architecture of human aggression. ''Trends in Neurosciences'', ''31''(3), 120–129. https://doi.org/10.1016/j.tins.2007.12.006 Eckardt, M., File, S., Gessa, G., Grant, K., Guerri, C., Hoffman, P., & Tabakoff, B. (1998). Effects of moderate alcohol consumption on the central nervous system. ''Alcoholism, Clinical and Experimental Research'', ''22''(5), 998–1040. https://doi.org/10.1111/j.1530-0277.1998.tb03695.x }} {{tip|Suggestions for this section: * Important aspects for APA style include: ** Wrap the set of references in the hanging indent template. Using "Edit source": <nowiki>{{Hanging indent|1= the full list of references}}</nowiki> ** Author surname, followed by a comma, then author initials separated by full stops and spaces ** Year of publication in parentheses ** Title of work in lower case except first letter and proper names, ending in a full-stop. ** Journal title in italics, volume number in italics, issue number in parentheses, first and last page numbers separated by an en-dash(–), followed by a full-stop. ** Provide the full doi as a URL and working hyperlink * Common mistakes include: ** incorrect capitalisation ** incorrect italicisation ** providing a "retrieved from" date (not part of APA 7th ed. style). ** citing sources that weren't actually read or consulted }} ==External links== Provide up to half-a-dozen [[Help:Contents/Links#External_links|external links]] to relevant resources such as presentations, news articles, and professional sites. For example: * [https://students.unimelb.edu.au/academic-skills/explore-our-resources/essay-writing/six-top-tips-for-writing-a-great-essay Six top tips for writing a great essay] (University of Melbourne) * [http://www.skillsyouneed.com/write/structure.html The importance of structure] (skillsyouneed.com) {{tip|Suggestions for this section: * Only select links to major external resources about the topic * Present in alphabetical order * Include the source in parentheses after the link }} [[Category:{{#titleparts:{{PAGENAME}}|3}}]] 2tozbde45fqlfvhh6swoilno6dslql7 6 286322 2414046 2022-08-13T07:52:50Z Young1lim 21186 {{Information |Description=Condition (20220811 - 20220810) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{cc-by-sa-3.0,2.5,2.0,1.0}} }} wikitext text/x-wiki == Summary == {{Information |Description=Condition (20220811 - 20220810) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{cc-by-sa-3.0,2.5,2.0,1.0}} }} == Licensing == {{self|GFDL|cc-by-sa-4.0,3.0,2.5,2.0,1.0}} r8ynt0t16oybzci6tgt6sv8uz20120c 6 286324 2414049 2022-08-13T07:54:01Z Young1lim 21186 {{Information |Description=Condition (20220812 - 20220811) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{cc-by-sa-3.0,2.5,2.0,1.0}} }} wikitext text/x-wiki == Summary == {{Information |Description=Condition (20220812 - 20220811) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{cc-by-sa-3.0,2.5,2.0,1.0}} }} == Licensing == {{self|GFDL|cc-by-sa-4.0,3.0,2.5,2.0,1.0}} ha3aqbeuxyhpe4zq6kpryzn2osq26k5 6 286325 2414052 2022-08-13T08:36:02Z Young1lim 21186 {{Information |Description=5MRV.3B: Stationary Random Process Examples (20220808 - 20220806) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{cc-by-sa-3.0,2.5,2.0,1.0}} }} wikitext text/x-wiki == Summary == {{Information |Description=5MRV.3B: Stationary Random Process Examples (20220808 - 20220806) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{cc-by-sa-3.0,2.5,2.0,1.0}} }} == Licensing == {{self|GFDL|cc-by-sa-4.0,3.0,2.5,2.0,1.0}} j3gte782s0as7fmzlqtv7rlrms7dpmd 6 286326 2414054 2022-08-13T08:36:59Z Young1lim 21186 {{Information |Description=5MRV.3B: Stationary Random Process Examples (20220809 - 20220808) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{cc-by-sa-3.0,2.5,2.0,1.0}} }} wikitext text/x-wiki == Summary == {{Information |Description=5MRV.3B: Stationary Random Process Examples (20220809 - 20220808) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{cc-by-sa-3.0,2.5,2.0,1.0}} }} == Licensing == {{self|GFDL|cc-by-sa-4.0,3.0,2.5,2.0,1.0}} 0clx6b09dlzfl3hyck4uaq58dery7ot 6 286327 2414058 2022-08-13T08:55:23Z Young1lim 21186 {{Information |Description=MP3.1F: Mutability - Lambda Calculus (20220810 - 20220809) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{GFDL}} }} wikitext text/x-wiki == Summary == {{Information |Description=MP3.1F: Mutability - Lambda Calculus (20220810 - 20220809) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{GFDL}} }} == Licensing == {{self|GFDL|cc-by-sa-4.0,3.0,2.5,2.0,1.0}} o7hti3uomsp1henyd9k4zatd1511grj 6 286328 2414060 2022-08-13T08:56:20Z Young1lim 21186 {{Information |Description=MP3.1F: Mutability - Lambda Calculus (20220811 - 20220810) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{GFDL}} }} wikitext text/x-wiki == Summary == {{Information |Description=MP3.1F: Mutability - Lambda Calculus (20220811 - 20220810) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{GFDL}} }} == Licensing == {{self|GFDL|cc-by-sa-4.0,3.0,2.5,2.0,1.0}} ltphz8efg53p60dvx829oyi6q9qn77u 6 286329 2414063 2022-08-13T09:31:06Z Young1lim 21186 {{Information |Description=ARM.2ASM: Vectored Interrupt (20220810 - 20220809) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{GFDL}} }} wikitext text/x-wiki == Summary == {{Information |Description=ARM.2ASM: Vectored Interrupt (20220810 - 20220809) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{GFDL}} }} == Licensing == {{self|GFDL|cc-by-sa-4.0,3.0,2.5,2.0,1.0}} elszncnvcia8v5mj3dlypi5v9hnfyhc 6 286330 2414065 2022-08-13T09:31:56Z Young1lim 21186 {{Information |Description=ARM.2ASM: Vectored Interrupt (20220811 - 20220810) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{GFDL}} }} wikitext text/x-wiki == Summary == {{Information |Description=ARM.2ASM: Vectored Interrupt (20220811 - 20220810) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{GFDL}} }} == Licensing == {{self|GFDL|cc-by-sa-4.0,3.0,2.5,2.0,1.0}} d5fhz7aaezkuj2r351djicnbl7t1e15 6 286331 2414067 2022-08-13T10:03:15Z Young1lim 21186 {{Information |Description=ARM.4ASM: UART Architecture (20220810 - 20220809) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{GFDL}} }} wikitext text/x-wiki == Summary == {{Information |Description=ARM.4ASM: UART Architecture (20220810 - 20220809) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{GFDL}} }} == Licensing == {{self|GFDL|cc-by-sa-4.0,3.0,2.5,2.0,1.0}} t06nbgm736h45dlcb7430ezisx00b71 6 286332 2414069 2022-08-13T10:04:06Z Young1lim 21186 {{Information |Description=ARM.4ASM: UART Architecture (20220811 - 20220810) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{GFDL}} }} wikitext text/x-wiki == Summary == {{Information |Description=ARM.4ASM: UART Architecture (20220811 - 20220810) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{GFDL}} }} == Licensing == {{self|GFDL|cc-by-sa-4.0,3.0,2.5,2.0,1.0}} pd87bendo6wulp7bml5un23w8jiedmi 6 286333 2414071 2022-08-13T10:24:48Z Young1lim 21186 {{Information |Description=ELF1.1E: Weak and Common Symbols (20220810 - 20220809) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{cc-by-sa-3.0,2.5,2.0,1.0}} }} wikitext text/x-wiki == Summary == {{Information |Description=ELF1.1E: Weak and Common Symbols (20220810 - 20220809) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{cc-by-sa-3.0,2.5,2.0,1.0}} }} == Licensing == {{self|GFDL|cc-by-sa-4.0,3.0,2.5,2.0,1.0}} g10p7hmjes8407nurli2w64a35dbhmi 6 286334 2414073 2022-08-13T10:25:33Z Young1lim 21186 {{Information |Description=ELF1.1E: Weak and Common Symbols (20220811 - 20220810) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{cc-by-sa-3.0,2.5,2.0,1.0}} }} wikitext text/x-wiki == Summary == {{Information |Description=ELF1.1E: Weak and Common Symbols (20220811 - 20220810) |Source={{own|Young1lim}} |Date=2022-08-13 |Author=Young W. Lim |Permission={{cc-by-sa-3.0,2.5,2.0,1.0}} }} == Licensing == {{self|GFDL|cc-by-sa-4.0,3.0,2.5,2.0,1.0}} 9p3j4jba3p59et8h6fznq8g4cvz9dl0