Wikipedia:Reference desk/Archives/Science/2014 September 9

Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

September 9

Seeds that need light to germinate

WHY do some seeds (gesneriads for example) need light to germinate? Is it a matter of needing to photosynthesize right from the outset of germination? Or is light needed as a trigger for the germination to begin? Or both?

How much light do they need? Bright, moderate, any detectable amount?

And is there a particular wavelength range that is essential? Thanks, C7nel (talk) 04:20, 9 September 2014 (UTC)

This is a very large topic, and I'm not sure that we can easily make general statements. First, yes, some seeds require light both to break dormancy, see Seed_dormancy#Physiological_dormancy. So, light can both act as a necessary trigger, and also be used for early photosynthesis. The idea is that, from a life history perspective, a plant would 'prefer' to wait until conditions are favorable, rather than germinate and die in a bad situation. E.g. a tree seed of a pioneer species in a dense forest might wait until a light gap forms from windthrow. In contrast, late-successional species like oak usually have larger seeds, and are more shade tolerant, and are not likely to use light cues. Anyway, here's a nice book chapter [1], and here are some research papers on the topic [2] [3] [4]. Here are two that specifically talk about the color of light. In short, yes, the amount and wavelength matter, but different species are likely looking for different features, as indicators of a good environment to establish in [5] [6]. SemanticMantis (talk) 14:07, 9 September 2014 (UTC)

Colour-blind?

How can I tell whether I have a deficient ability to see blue in one eye, or a deficient ability to see red and green in the other eye. How do I know which one is the baseline? For that matter, how do I know that either one is a baseline? What is this condition called, where colour vision differs between the left and right eyes? Plasmic Physics (talk) 08:40, 9 September 2014 (UTC)

Answering the first part of your question would go close to our prohibited area of medical advice, but pointing you at Color blindness can only help. HiLo48 (talk) 08:51, 9 September 2014 (UTC)

Hardly. Whatever answer I may receive is inconsequential with regard to my decision, either for or against seeking medical assistance. For the record, I am not of the persuasion of seeking such assistance. This is merely enquiry for interest's sake. I have also already read Color blindness prior. Plasmic Physics (talk) 09:52, 9 September 2014 (UTC)

I'd suggest doing a standard colorblindess test with one eye closed, writing down the answers, then redo it with the other eye, perhaps a few days later. Only then, check the answers. But if you have any concerns about your eyes, see an optometrist. ---- CS Miller (talk)

Clearly, doing one-eye colorblindness tests will reveal whether you're perceiving things radically differently with each eye - but (as CS Miller points out), you'll remember what the answers are between one test and the next - which could easily skew the results. I wonder if there are alternative sets of those colored-dot number tests out there? I bet there are because the standard tests use numbers and they probably want to use the tests for people who can't read or don't know their numbers. Maybe you could use the number tests for one eye and some alternative test for the other?

I notice a slight shift in some shades of red between my left and right eyes - but not sufficiently to show up in color blindness tests. I suspect the reason in my case is that I have different degrees of short-sightedness in my two eyes (my glasses prescription reveals this quite clearly) - and we know that light of different colors is focussed at different depths, so it could easily be that red is inherently blurrier than green or blue in one eye...but that doesn't quite explain the very slight color shift. Another possibility would be some kind of filtering of red light in one eye (eg if one had a cataract in one eye) - but I've been tested for that, so that isn't it. What makes this kind of thing difficult to pin down is that brain plasticity will result in us unconsciously 'tuning' our vision to work as well as possible given whatever weirdnesses are going on - and when our eyes change over time, it can take a while for brain adaptation to catch up. So it can be surprisingly hard to tease out these effects. SteveBaker (talk) 14:27, 9 September 2014 (UTC)

I found the Farnsworth-Munsell 100 hue test, that is test for which the correct answer cannot be remembered, as it depends entirely on the hue, there are no defining markings involved. I tried an online version of this test, although I don't know how reliable it is, I got a ratio of 15/27. [7] Plasmic Physics (talk) 23:54, 11 September 2014 (UTC)

You might also be interested in mosaic (genetics) and chimera (genetics) which can easily cause that sort of thing. Dmcq (talk) 10:21, 9 September 2014 (UTC)

If either, I'm most likely a mosaic. Plasmic Physics (talk) 23:54, 11 September 2014 (UTC)

Generally inherited color blindness affects both eyes, but acquired color blindness can affect only one eye as a result of disease, head trauma to the occipital lobe, chemical exposure of the eye, etc. --Mark viking (talk) 19:55, 9 September 2014 (UTC)

I think that this is probably congenital, since I've had it for as long as I remember, unless that bout of meningitis did more than just give me a mild case of amelogenesis imperfecta. Plasmic Physics (talk) 23:54, 11 September 2014 (UTC)

Does everyone perceive red and blue light in the same way?

(Splitting this off into a separate question so as not to hijack our OP's original question SteveBaker (talk) 14:15, 9 September 2014 (UTC)) On a related theme, how do I know that what I see as red you don't see as blue, we just use the same terminology to describe things we perceive differently? --Dweller (talk) 11:40, 9 September 2014 (UTC)

See Qualia -- Roger (Dodger67) (talk) 12:33, 9 September 2014 (UTC)

We all agree that light in a particular frequency range is "red" and in another frequency range is "blue". We know that the same groups of cells are activated when we each see "Red" or "Blue". We agree that rooms painted in all red feel "warm" and those painted in blue are "cool"...any comparison you can make come out the same. Differences are things like the fact that I like green and my wife prefers blue - does that hint that we're perceiving them differently in our heads? I don't think this is even a meaningful question. You can only say that what you see as "red" I'm really seeing as "blue" is kinda meaningless because you're using these words that have predefined meanings that attach them to particular ranges of light frequency.

What you're really asking is whether two people's perceptions of anything whatever can be meaningfully compared. We can see that similar areas of the brain are activated when we think similar thoughts - which suggests that we're perceiving things similarly - but we also know that if we put you in a room that's bathed in red light for 10 minutes - then go back to white light and immediately show you red and blue objects, then your own perceptual feeling for what is red and blue have shifted temporarily.

I actually believe this is a meaningless question. SteveBaker (talk) 14:15, 9 September 2014 (UTC)

So meaningless you typed up ~230 words about it? I dunno, I thought this was a standard conversation everybody had at some point. Anyway, the qualia article is probably our best WP ref, but OP might be interested epistemology and ontology, which also come into play if we want to discuss this scientifically. For fun, here's a classic paper on the topic of color perception [8]. Spoiler: psychedelic drugs change how we perceive and discriminate colors. So, If OP is on LSD and I'm not, we probably are not perceiving blue light the same way... SemanticMantis (talk) 14:28, 9 September 2014 (UTC)

OP here. Really interesting. I'd never imagined that drug taking could change colour perception (sheltered life, eh?). That does suggest a totally subjective experience. Thank you. --Dweller (talk) 14:29, 9 September 2014 (UTC)

You may be interested in the field known as behaviorism. It relates pretty closely to your initial question, insofar as it looks at psychology and related fields as only those phenomena which can be directly observed, and ignores (or glazes over) those "purely mental" phenomena as unmeasurable, and therefore outside of the realm of science to answer. SteveBaker's answer is a pretty good Behaviorist response to the question you asked. --Jayron32 14:38, 9 September 2014 (UTC)

We are still biological machines that can in pinciple be described in a precise formal mathematical way. So, at any time whether you have taken drugs or not, you are nothing more than a machine that is running a well defined algorithm. See the Church–Turing–Deutsch principle. So, unless you are sceptical about the idea that physics applies to everything including human beings, we should assume that subjective perceptions should be indentified with computational states of algorithms. Given two slightly different algorithms A and B, you can try to approximately describe B in terms of A by modifying the inputs to A. If you could run B by interchanging red and blue and then feeding that input to A and then in the output also interchange red and blue, then that would mean that B experiences red in the same way as A experiences blue. Count Iblis (talk) 16:35, 9 September 2014 (UTC)

• Unequivocally not. There are two types of red-green colorblindness; one where red is seen as green, and one where green is seen as red. If a rare person had both types of colorblindness, he wouldn't be "colorblind" he'd be a trichromat whose perception of red and green was swapped. See the famous work of Stephen Palmer at M.I.T. μηδείς (talk) 17:26, 9 September 2014 (UTC)

WHAT?!? That's utter nonsense. There are actually at least eight kinds of red/green color blindness. You can be missing the red sensors, missing the green sensors, (rarely) missing both red and green, you can have a weak red sensor, a weak green sensor, and rarely, both red and green can be weak, red can be weak and green absent or green can be weak and red absent. In none of those cases are red and green "swapped". If you're missing both red and green sensors, then only shades of blue are seen...although in practice it's a little more complex than that because comparing the outputs of the rods and the cones, the person can still get some greatly diminished sense of things that are red/green/yellow/orange rather than blue. But swapped colors would imply that both color sensors exist, but are somehow wired up differently. Such a hypothetical situation would probably result in perfectly normal vision because brain plasticity would kick in and sort it all out so the person would have no problem figuring out what's red and what's green. SteveBaker (talk) 18:31, 9 September 2014 (UTC)

We have an article on color blindness that covers what SteveBaker is talking about. The reason it's called "red-green blindness" is because one can't distinguish between red and green (you're "blind" to the difference between them), not because they're swapped. The most common color blindness (partial red-green color blindness, "deuteranomaly") is caused by the green cones having their response shifted towards red. -- Consumed Crustacean (talk) 18:48, 9 September 2014 (UTC)

What, CC would happen if you carried both mutations, red shifted to green and gree shifted to red? I suggest you read palmer, not me nor Baker. μηδείς (talk) 20:50, 9 September 2014 (UTC)

I was specifically talking about what Baker said RE: what color blindness is, in his response to your erroneous statement that color blindness is a swapping of colors, I haven't followed whatever the rest of this conversation is about. If you carried both mutations, as far as I can gather you would suffer the symptoms of each mutation (i.e. your color responses to red and to green would be weakened so that things close to the 'edges' of either would appear darker, and you would have an even more difficult time distinguishing the two colors); both mutations are carried on separate genes [9] and I can't find any information on any shared interactions between them. That would be quite a rare condition, though. -- Consumed Crustacean (talk) 02:01, 10 September 2014 (UTC)

Steve, if you are not a fool you are a screamer, and I have no interest in your OR or discussing this further than I do suffering through Philosophy 101 again (or Biololgy for that matter. But I will say Palmer's argument and the conclusions it implies might make one gasp. Stephen E. Palmer is the authority on vision, he's written the standard college text, Vision Science, and he's shown that we cannot interchange red green and green red color maps, and that this can be scientifically demonstrated. The following paper is easily found as a pdf at google:

Color, consciousness, and the isomorphism constraint

Stephen E. Palmer

Department of Psychology, University of California, Berkeley, Berkeley, CA 94720-1650

palmer@cogsci.berkeley.edu socrates.berkeley.edu/~plab

Abstract: The relations among consciousness, brain, behavior, and scientific explanation are explored in the domain of color perception. Current scientific knowledge about color similarity, color composition, dimensional structure, unique colors, and color categories is used to assess Locke’s “inverted spectrum argument” about the undetectability of color transformations. A symmetry analysis of color space shows that the literal interpretation of this argument – reversing the experience of a rainbow – would not work. Three other color-to color transformations might work, however, depending on the relevance of certain color categories. The approach is then generalized to examine behavioral detection of arbitrary differences in color experiences, leading to the formulation of a principled distinction, called the “isomorphism constraint,” between what can and cannot be determined about the nature of color experience by objective behavioral means. Finally, the prospects for achieving a biologically based explanation of color experience below the level of isomorphism are considered in light of the limitations of behavioral methods. Within-subject designs using biological interventions hold the greatest promise for scientific progress on consciousness....

μηδείς (talk) 20:39, 9 September 2014 (UTC)

I think what made SteveBaker incredulous is your claim that some dichromats perceive red as green and others perceive green as red. Is there anything in Palmer's paper that led you to think that? I think that dichromats see only two of the three opponent pairs, which at least for protanopes and deuteranopes would mean that they never experience red or green, only yellow and blue. That's supported at least by the fact that unilateral protanopes and deuteranopes report that they see only yellow and blue in the dichromatic eye. (Source: Color blindness#Dichromacy, which has an external reference.)

As far as Palmer's paper goes, he's merely pointing out that there are no automorphisms of the psychological color space that preserve psychological distance. That doesn't mean that swapping the genes for R and G pigments would measurably swap the perception of red and green. Almost certainly the wiring of the cones is somehow determined dynamically by firing patterns, not by whatever mechanism picks one of the three pigments, meaning that the gene-swapped person would have normal color vision, both experimentally and (presumably) in terms of qualia. -- BenRG (talk) 02:04, 10 September 2014 (UTC)

There are all sorts of colorblindness, but Baker's response seemed about as relevant as saying, in response to hearing that achondroplastic dwarves may find reaching certain objects difficult, that not all dwarves are achondroplastic. What matters is it is possible to carry the genes for what would normally be seen as two types of color blindness, and yet be a trichromat with a different set of qualia from the wild type. Palmer mentions that the people in his example would see cyan as brighter than yellow, and would disagree with wild type humans as to which colors as we name them would be "unique" in the way that there are unique shades of blue, red, yellow and green, something which most trichromats agree on.

If color space were perfectly symmetrical, i.e., if yellows took up as much of the color solid as blues, these people would be indetectable by survey. But color space is not symmetrical. Blues and greens fill far more of it than do reds, and especially yellow. In an RGB space divided into 125 (5x5x5) equally spaced slots, you will get pure yellow and yellow-white as the only unambiguously yellow tones, with mustard and yellow green as well, but they will not be pure yellows. The blues, however will take up a much large number of slots, with maybe ten perceived as darker or lighter shades of blue, but not as purples or greens.

This is whether or not you count cyan as blue.

Such reversed tricrohomats will be rare necessarily just by chance, and they may be acculturated to know that shades which appear close to them in their color space my no appear close to other people, and respond that way. A study would have to involve tens of thousands, and would prefferably have to be done with children who have an unsolidified notion of color or with people whose languages lack more than two or three color terms. In any case e know that the color space is not symmetrical per Locke's assumption and that it is biologically determined at the chemical level. Palmer speaks himself better than I can, so I refer further inquiry to the sources. μηδείς (talk) 18:41, 10 September 2014 (UTC)

To my surprise Palmer does say (p.926, last paragraph) "a persuasive argument can be made that such red-green-reversed perceivers may actually exist", with the argument being just that people with swapped L and M pigment genes ought to exist (though he also says "no one has ever managed to identify such a person"). I don't find this argument persuasive, nor would I expect anyone to, for the reason I gave above: I'd expect the wiring of the color-processing stages to be determined dynamically by the actual pigments (e.g. by cone firing patterns in infancy). You would only get a red-green-reversed perceiver if the pigments were associated with different cone types in such a way that swapping the pigments would leave the containing cone still behaving as though it contained the other pigment in all later stages. I don't know what biological mechanism could achieve that. Karel Kranda says the same thing in his response (p.959): "As there is no chance here of getting red wine in vinho-verde bottles, this 'mutant' should preserve normal colour sensation." Kranda also claims that the natural incidence of such mutants should be less than 1 in 10¹². It's not the product of the incidences of protanopia and deuteranopia because they are usually caused by defective genes, not copied genes, as far as I know. -- BenRG (talk) 20:28, 11 September 2014 (UTC)

• Although it is referenced from the qualia article mentioned above, I'd like to give a more direct pointer to the inverted spectrum article, which is specifically about this problem. Looie496 (talk) 14:04, 10 September 2014 (UTC)

• "The argument dates back to John Locke.[1] It invites us to imagine that we wake up one morning, and find that for some unknown reason all the colors in the world have been inverted. Furthermore, we discover that no physical changes have occurred in our brains or bodies that would explain this phenomenon. " This violates the laws of physics. Two identically prepared systems, one is the original persion and the other is the same person with inverted color perception (which by the assmuption of this thought experiment can nevertheless can be chosen to be physically identical to the original person) would be distinguishable in an experiment (you can ask if the way they perceive colors is the same as the way they perceived colors yesterday, one person will say yes the other will say no.). Count Iblis (talk) 19:36, 10 September 2014 (UTC)

The scenario as stated requires substance dualism. Looie496 (talk) 12:57, 11 September 2014 (UTC)

Well, the point is that if you pose identical questions to the two people and they consistently give different answers, that's ipso facto a physical difference. The question and answer are encoded physically in sound waves, and there's a causal link between them, and if you want to claim that some part of the causal chain exists outside of physical reality then you have to find some other way of defining "physical reality" than by causal connection, which is rather difficult (as discussed in Physicalism#Definition of physical). -- BenRG (talk) 21:52, 11 September 2014 (UTC)

What about animals?

Tangential to above topic

Thusfar, the above conversation has been limited to humans. One could say that certain animals perceive biased colors due to a shifted or expanded spectrum. Would a bird that can see ultraviolet perceive what we see as "blue" as being "green" (or at least greenish-blue)? And what about infrared sensing in snakes? They are technically colorblind, but do they somehow merge an overlay of the Mach band infrared image with optical information in order to parse something similar to "color" in their brain? [10], [11], [12], [13], [14], etc.   —71.20.250.51 (talk) 18:04, 9 September 2014 (UTC)

We have no idea what qualia are. For all we know, different humans with normal color vision have qualia that are totally different in some way we don't understand. Or maybe the colors we all see are the only possible color qualia and are shared by all animals. -- BenRG (talk) 19:38, 9 September 2014 (UTC)

• Qualia, linked for convenience (interesting article). —[oops- didn't notice Roger (Dodger67)'s link above]— 71.20.250.51 (talk) 20:23, 9 September 2014 (UTC)

What kind of electricity energetic we need?

We will need a powerful electricity energetic or a small power electricity energetic if the raw energy resources in the World will been end?--Alex Sazonov (talk) 18:02, 9 September 2014 (UTC)

If I understand your question correctly, searching for distributed vs. centralized energy model provides useful results. The closest on Wikipedia seems to be Distributed generation. 71.20.250.51 (talk) 18:15, 9 September 2014 (UTC)

Does I understand correctly, that the centralized electricity energetic is always been a powerfully electricity energetic of powerful electric generation?--Alex Sazonov (talk) 08:00, 10 September 2014 (UTC)

Click to enlarge →

Generally speaking, yes; but not always. Many modern Electrical grids include a mix of power sources (big and small). Typically there are a few large power plants (coal, nuclear, etc.) on the transmission side of the grid, and many small power sources (solar, wind, etc.) on the distribution side of the grid. See diagram→

—71.20.250.51 (talk) 20:11, 10 September 2014 (UTC)

For general reference on resource scarcity, see Hubbert_peak_theory#Hubbert_peaks and links therein. SemanticMantis (talk) 20:56, 9 September 2014 (UTC)

Could a diesel electric generator been generate a steady corona discharges?--Alex Sazonov (talk) 09:26, 10 September 2014 (UTC)

If the raw energy resources in the World will been end, no. Because it'll need diesel and we don't have any. We'll have far bigger worries than how to create a corona discharge at that time. How to charge our phones, first and foremost. InedibleHulk (talk) 09:59, 10 September 2014 (UTC)

Could a diesel electric generator been create a mechanical speed acceleration which been required to generate a steady corona discharges?--Alex Sazonov (talk) 12:01, 10 September 2014 (UTC)

I think that the mechanical speed accelerations are not been unlimited, especially in diesel electric generators!--Alex Sazonov (talk) 17:13, 10 September 2014 (UTC)

How does to express correctly the physical-mathematical acceleration of speed powerfully rotation?--Alex Sazonov (talk) 17:29, 10 September 2014 (UTC)

What is the maximum electric charge could been create electromagnetic induction in nature, that is, does an electromagnetic induction had a limits in nature?--Alex Sazonov (talk) 17:05, 10 September 2014 (UTC)

Does it been possible to reaching a absolute values of the force of the electric charge or the force of dynamics of the electric charge in the space of natural magnetism of the planet Earth?--Alex Sazonov (talk) 10:53, 11 September 2014 (UTC)

This is not a direct answer, but you might be interested in Tesla's Wardenclyffe Tower, which seems to fit what you are describing.  —71.20.250.51 (talk) 20:20, 10 September 2014 (UTC)

I suppose that Nikola Tesla in studying of the properties of electromagnetic induction was first who been create an electro-thermodynamic plasma reaction of unmanaged type. As far as I know, the Russian scientist Pavel Nikolayevich Yablochkov was studied in corona discharges of electric current for been used in the first electric incandescent lamps.--Alex Sazonov (talk) 12:49, 11 September 2014 (UTC)

Thank you! I believe that diesel electric generators are not been able to generate a powerfully electric, because diesel electric generators do not had a much-speed rotation, so that diesel electric generators are always been a small power electricity energetic of none power electric generation.--Alex Sazonov (talk) 05:55, 11 September 2014 (UTC)

Does been a differences in the generations of an electric charge, or the dynamics of the electric charge by an electromagnetic inductive field and the magnetic inductive field?--Alex Sazonov (talk) 14:55, 11 September 2014 (UTC)

Does been a differences between the powerful electric generation and none power electric generation?--Alex Sazonov (talk) 07:28, 12 September 2014 (UTC)

In physics, is always been taken to distinguish all of the electric charges on the powerful (forcing) electric charges and low electric charges!--Alex Sazonov (talk) 03:53, 13 September 2014 (UTC)

What is the potential volume of backward electromagnetic induction are always had a city electric grid and national electric grid?--Alex Sazonov (talk) 06:23, 11 September 2014 (UTC)

What force is been needed to the electric charge or the dynamics of the electric charge (electric current) in order to overcome (to punching) the volume of backward electromagnetic induction of city electric grids and national electric grid?--Alex Sazonov (talk) 08:35, 11 September 2014 (UTC)

---

Note:The work of the electric current is always been considered the work of the backward electromagnetic induction!--Alex Sazonov (talk) 06:32, 11 September 2014 (UTC) Backward electromagnetic induction in conductors with electricity, always been creates by natural magnetism of the planet Earth.--Alex Sazonov (talk) 07:27, 11 September 2014 (UTC)

A commercially available diesel generator can produce up to up to 2,000 kW, and can be linked together with as many units as needed. Inrush current might also be a useful link? I am not understanding the use of "backward" in relation to electromagnetic induction. —71.20.250.51 (talk) 16:50, 11 September 2014 (UTC)

The force which been resists to an electric current in the conductors also always had been an electromagnetic nature.--Alex Sazonov (talk) 18:48, 11 September 2014 (UTC)

Hysteresis?   71.20.250.51 (talk) 19:44, 11 September 2014 (UTC)

In conductors with electric current any doing magnetism always been the property only of backward induction which in conductors with electric current always had been an electromagnetic nature, so that it always been the backward electromagnetic induction.--Alex Sazonov (talk) 06:49, 12 September 2014 (UTC)

Are you looking for Lenz's law? Dbfirs 07:07, 12 September 2014 (UTC)

Lenz's force and Lorentz force are always had no any magnetism, and I would been argue that the nature of the resisted force is always been identical to the nature of the doing (acting) force.--Alex Sazonov (talk) 08:59, 12 September 2014 (UTC)

Did you read the article which I linked? It says "Lenz's law states that the current induced in a circuit due to a change or a motion in a magnetic field is so directed as to oppose the change in flux or to exert a mechanical force opposing the motion.". Dbfirs 15:26, 15 September 2014 (UTC)

Charles-Augustin de Coulomb was investigated the force of electric charge, André-Marie Ampère was investigated the force of electric current and force of dynamics of electric current, Hendrik Antoon Lorentz and Heinrich Friedrich Emil Lenz were investigated the force of electric charge and force of electric current - force of dynamics of electric current in general (fully), nuclear physics was investigating the force of dynamics of electric charge.--Alex Sazonov (talk) 11:49, 12 September 2014 (UTC)

All Faraday's Laws are always been right only to electromagnetic induction, but not to magnetic induction! (In during of changing the magnetic volume of the Faraday's inductive coil the Faraday's law is always been right.)--Alex Sazonov (talk) 12:33, 12 September 2014 (UTC)

James Clerk Maxwell was argued that increasing the magnetic volume (inductive volume) of the inductive coil could never been increased the force of electric current and voltage.--Alex Sazonov (talk) 22:17, 12 September 2014 (UTC)

Nikola Tesla was right in the statement that all plasma reactions always been proceed in according to the laws of electromagnetic induction.--Alex Sazonov (talk) 03:38, 13 September 2014 (UTC)

"Attempting to gain complete control" - anorexia nervosa, masturbation, etc

Our article on anorexia nervosa says:

Despite the fact that the physiological cause behind each case of anorexia nervosa is different, the most common theme seen across the board is the element of self-control. The underlying cause behind the disorder is rarely about the food itself; it is about the individual attempting to gain complete control over an aspect of their lives, in order to prove themselves, and distract them from another aspect of their lives they wish they could control. For example, a child with a destructive family life who restricts food intake in order to compensate for the chaos occurring at home.

and this reminded me of a question I'd forgotten to find an answer to. A few years ago, when the subject of anorexia nervosa came up in a discussion, one man said that although he'd never had an eating disorder he had worried so obsessively about masturbation during his early teens that finding ways to avoid thinking about masturbation, counting the days since he had last masturbated, and punishing himself for masturbating were taking over his life. Of course we asked what that had to do with anorexia; he said that his family was breaking up at the time, and there was some emotional abuse and so on, and so obsessing about something else became a distraction. And that's pretty much how the passage above describes a cause of anorexia nervosa.

So my questions are: is there a name for the general pattern where it is about the individual attempting to gain complete control over an aspect of their lives, in order to prove themselves, and distract them from another aspect of their lives they wish they could control? And is there a particular name for, or any references about, this particular instance of the pattern with sexuality (possibly particularly adolescent sexuality)? If so, it could make for a useful/interesting article for WP:SEX. The Wednesday Island (talk) 21:44, 9 September 2014 (UTC)

Maybe Displacement (psychology)? --Jayron32 01:52, 10 September 2014 (UTC)