Wikipedia:Reference desk/Archives/Science/2014 January 31

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January 31

Valproic acid as a way to a musical talent.

Well, well, well. I've always thought the musical talent, especially the absolute ear, that is the ability to perceive tones as parts of musical scale is genetically driven. You have to be born with it. Encyclopedia Britannica I recall claims there are 3 genes that govern that. Now in the latest Week magazine, which is a short compendium of assorted facts, they published a result of latest study whereas people were given Valproic acid and lo and behold they develop absolute ear. I wonder what the erudite public think about it.

Along the same lines, there has been apparently not an apocryphal story that a Canadian individual sustained a head trauma and after that he found himself with a musical ability that manifested in him learning to play 3 or 4 musical instrument and at the time of the report he was going through the rest of symphony orchestra. How about that? Thanks, --AboutFace 22 (talk) 01:13, 31 January 2014 (UTC)

The usual term is absolute pitch. The original source for the information you are referring to is http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3848041. If you are interested in this topic, the book Musicophilia by Oliver Sacks tells a number of curious stories about the relationship between music and the brain, including gains in ability as a result of brain damage. Looie496 (talk) 05:23, 31 January 2014 (UTC)

Great question, which raises so many others! The study was small, but the result was impressive - I'll want to see it duplicated. More to the point, I'll want to see if it has benefits in trying to pick up a foreign language as an adult! Also, there are a range of HDAC inhibitors; even ordinary butter (containing esters of butyrate) may be a weak one. I'd like to see if the correlation holds up for all such inhibitors - and if so, why exactly is histone deacetylation tied to memory? That certainly suggests some things having to do with epigenetic markup of specific genes as a means to remember, which can potentially extend even between generations. See [1] And we always thought it was a joke to say that guys think with their balls! All those billions of neurons, yet to imagine that the hidden complexities of one single gamete might conceal a meaningful fraction of the mind. Wnt (talk) 06:09, 31 January 2014 (UTC)

I suppose I'm verging on medical advice here, but one should be careful about experimenting with this sort of stuff. There are probably functional reasons why the brain closes off critical periods at a certain age. It's not inconceivable that re-activating critical periods could lead to erasing of certain types of memory, for example. Looie496 (talk) 18:54, 31 January 2014 (UTC)

Well, the trouble with this information (the original one) is that many people are prescribed Depakote which is divalproex sodium. Is it different from valproic acid so much? Nobody have heard that the Depakote recipients all of a sudden begin playing Mozart. It is hardly congruent in my opinion. --AboutFace 22 (talk) 17:46, 31 January 2014 (UTC)

There's a discussion with some of the authors of the paper here. there was a report on it in New Scientist here but you will need a subscription to read it all. They did say in there "The brain shuts down critical periods for good reason – it would be disastrous to have it rewiring itself extensively for the rest of your life." although Hensch says that as it's an approved treatment for mood disorders and epilepsy he didn't think that was a problem. They also said it may have implications for the treatment of several disorders, including autism, that may result from mistimed critical periods. Richerman (talk) 21:48, 31 January 2014 (UTC)

Valproate is a well known anticonvulsant, not well known for memory problems (though our article does provide an impressive list of pleiotropic side effects that seems in keeping with the fundamental nature of histone modification). My assumption would be that the reopening of critical periods either (a) isn't all that dramatic, or (b) only affects things for which there was no selective pressure in prehistory. It's the latter alternative, of course, that is potentially exciting. Wnt (talk) 23:40, 2 February 2014 (UTC)

Nuclear fuel and skin

How properly to hold nuclear fuel pellets

It would appear from this image that it's best to hold nuclear fuel with tongs or something else to prevent direct skin contact with the fuel. But what if you touch it with your fingers for a few seconds? Surely you wouldn't instantly notice a huge effect; Louis Slotin's encounter with the demon core initially gave him "only" a weird taste in his mouth and a burning sensation in his hand (this is far far smaller, and it's clearly not critical), but I wonder if you might start experiencing some sort of sensation later. I also don't know whether this kind of exposure would be associated with a statistically significant increase in radiation-related illness down the road. Finally, note that I'm definitely not in a position to be touching nuclear fuel, and I wouldn't if I could; it's not a medical advice question :-) Nyttend (talk) 01:51, 31 January 2014 (UTC)

Unused nuclear fuel gives off mostly alpha radiation, which is almost entirely stopped by your skin. Also, as long as it's for a uranium reactor, it has such a long half-life that it's not particularly radioactive anyway. I imagine the "best practices" might be to avoid touching it, out of an abundance of caution, to keep from dissolving any trace of it in your sweat and somehow getting it inside your body, where it would be slightly more risky, if only as a heavy metal. Or, possibly, the caution is in the other direction (avoid contaminating the pellet somehow, not sure with what).

Now, if it's used nuclear fuel, that's another matter entirely. Then you've got lots of much more radioactive isotopes. --Trovatore (talk) 02:06, 31 January 2014 (UTC)

Hadn't even thought that the tongs might be there to prevent me from damaging it. Thanks for the explanation re alpha radiation (been way too long since I had classes at all related to this; I didn't even know where to look), and also the pointers on the spent fuel. I was indeed assuming that we were talking about unused fuel pellets, basically because I got the impression from Spent fuel pool and Spent nuclear fuel that the used pellets are left in the rods rather than being taken out by people with tongs. Nyttend (talk) 02:22, 31 January 2014 (UTC)

Think you will find the the tongs are to reduce the contamination of the gloves which can then be deposed of as low level waste. The gloves (if they don't have any perforations, make the hands easier to clean without setting of the radiation hand-body- monitors before exiting from the facility. In short, it is all part of the confinement of hazardous materials. Anything I handle with tongs (including the mother-in-law's cremated offerings on the barbecue) I consider, as not fit for entering my personal bio-space.--Aspro (talk) 18:04, 1 February 2014 (UTC)

It comes down to money. Wikipedia has an article called Low-level radioactive waste policy of the United States. A cubic meter of spent and compressed (to reduce volume) gloves, contaminated with a few micro-curies of enriched Uranium (– thanks to those tweezers in the photo), should be less radioactive than a cubic meter of natural uranium ore. Thus, cheap to dispose in a suitable landfill site.--Aspro (talk) 00:01, 2 February 2014 (UTC)

RGB colour model

The CIE xyz color space. y is luminance, and x is some combination of not-blue colors chosen to be non-negative, I think. Wnt (talk) 02:53, 31 January 2014 (UTC)
y is not luminance. You are probably confusing it with (capital) Y. This space is CIE xy, not CIE XYZ. -- BenRG (talk) 10:09, 31 January 2014 (UTC)

At RGB color model and various other articles, it is mentioned that the RGB model cannot reproduce all colours, but I can't find a clear explanation of why. Any perceived colour can be described by three numbers, measuring the levels of response of the three types of receptor in the eye. Why is it not always possible to reproduce those three numbers by combining the correct quantities of red, green and blue, for some sensibly chosen red, green and blue wavelengths? Three equations in three variables should be solvable? 86.130.66.42 (talk) 02:24, 31 January 2014 (UTC)

From reading the article, I get the impression that it's saying basically "This color model doesn't explain how we end up with some of the colors, but we've not come up with a better explanation". Beyond that I can't say; I am unable to understand concepts such as chromaticity and color triangles properly. Nyttend (talk) 02:29, 31 January 2014 (UTC)

The article Imaginary color may be getting at something for you. --Jayron32 02:33, 31 January 2014 (UTC)

The CIE 1931 color space article explains some of it. Basically, the idea is that absolute monochromatic light runs around the edge of the true color palette, and choosing just three colors from that don't give all the possibilities because you don't have red, blue, and green receptors - you have cones that are maximally sensitive to those frequencies. So a violet color might excite blue less, but green even less proportionally to it than the blue + some red color you would get on a computer screen. The thing I don't get myself, however, is why the RGB color triangle doesn't touch the curve running around the edge of the color space at the frequencies of the emitters. Wnt (talk) 02:53, 31 January 2014 (UTC)

There are a lot of color spaces called "RGB". CIE RGB does use monochromatic primaries, and there are probably others. sRGB doesn't because it isn't practical to use monochromatic primaries in real displays, and with only 8 bits per color channel it's good to be able to discriminate more colors within the actually reproducible region. Incidentally, the cones aren't actually maximally sensitive to red, green, and blue. -- BenRG (talk) 10:09, 31 January 2014 (UTC)

A large part of the problem is that in the real world, light can be infinitely bright - but in these chromaticity diagrams, there is an absolute white. Another issue is that the frequencies chosen for R, G and B don't perfectly match the peak of the sensitivity curves for the sensors in human eyes - and because people differ in what those frequencies are, the match can never be perfect. Note, for example, that women are much more sensitive to small differences in colors midway between blue and green than men are. The chromaticity diagram (and it's physical incarnation in TV screens and computer monitors) is a compromise. SteveBaker (talk) 03:14, 31 January 2014 (UTC)

"A large part of the problem is that in the real world, light can be infinitely bright - but in these chromaticity diagrams, there is an absolute white" – this makes no sense. In all of these 2D diagrams, the brightness is normalized (it's the third dimension). The white on that diagram is a white of arbitrary intensity. "Another issue is that the frequencies chosen for R, G and B don't perfectly match the peak of the sensitivity curves for the sensors in human eyes" – it's true that they don't match, but that has nothing to do with the problem. Given how close the L and M peaks are, matching the primaries to the peaks would make color reproduction much worse. -- BenRG (talk) 10:09, 31 January 2014 (UTC)

w o w -- I never heard this one before. Looking it up it seems there's something to it. [2] -> [3] [4]. This might have to do with differences in brain development based on androgens, or the fact that women inactivate different copies of color-sensing genes in different cells, at least potentially allowing a weak version of tetrachromatic vision. This seems to have potential consequences for Wikipedia itself. For example, consider a .svg figure in which different levels of infant mortality on a continent are shaded differently. Potentially we could (with some upgrades to the software) allow users to define parameters so that these would be generated on the fly differently, so that women could have a setting to have more levels of mortality labelled than the same figure as viewed by men (and the color blind would have their own options, perhaps grayscale and even fewer levels, etc.) [Of course, I do not mean to imply that these settings should be imposed other than by individual choice of the user!] Wnt (talk) 05:42, 31 January 2014 (UTC)

RGB system of color representation is a vector system. The problem is that the vectors that constitute the basis are not orthogonal. The origin of the system of basic vectors is located outside of the plane of reference that we see as the color triangle. They intersect the plane of reference at the corners of the triangle. There is no way to express a color outside of the triangle through the basic vectors. Apparently the basic vectors (the coordinate system) were chosen for technical reasons. --AboutFace 22 (talk) 03:31, 31 January 2014 (UTC)

I don't understand what you mean by "not orthogonal" here. The problem is that you can't form a triangle covering the whole color space unless the vertices (the primaries) are outside the color space, i.e. not physically realizable colors. -- BenRG (talk) 10:09, 31 January 2014 (UTC)

• (OP) I had a later thought. Three equations in three variables should be solvable, but solutions to some cases may require negative amounts of R, G and/or B. Is this the answer? Is it the solutions that require a negative R, G or B that cannot actually be realised in the RGB model? 86.130.66.42 (talk) 03:38, 31 January 2014 (UTC)

In a word, yes. Treated as an unbounded linear system (a vector space), if any scalar multipliers for a set of basis vectors is permitted, the entire space could be reached. Impose range limitations on those scalars, and effects such as this arise. —Quondum 06:23, 31 January 2014 (UTC)

Yes, I think that's the best answer to your original question.

Some people above seemed to think that this is an accident of physiology and/or poor standardization, but it's actually (almost) unavoidable. If you have trichromatic vision and the cone responses are linear (output proportional to the number of incoming photons at a given frequency) and nonnegative (more photons doesn't decrease the output), then, ignoring intensity, the space of possible cone responses is a triangle. The monochromatic spectrum is a curve inside the triangle. The physically realizable colors are the convex closure of that curve. The primaries you choose for your display have to be physically realizable. The color sensations you can reproduce with them are the convex closure of the primaries, i.e., a triangle inside the curve inside the triangle. There's no way the inner triangle can be the same as the outer one, or even large enough to cover all the physical colors. Your choices are to pick unphysical primaries (like CIE XYZ) and have positive coordinates for every color, or pick physical primaries and have negative coordinates for some colors.

(This would be avoided if the monochromatic curve was actually triangular, but that would imply poor hue discrimination near the vertices, so it's probably evolutionarily disfavored.) -- BenRG (talk) 10:09, 31 January 2014 (UTC)

Thank you both for your affirmative answers. I get it now. Follow-up question: I have never knowingly seen any colour that I felt could not be reproduced on an RGB display (ignoring non-reproducible effects caused by texture, reflectivity, etc.). The colours that I see around me don't look any different to my eye in real life than they would in a good colour photograph. Are other people's experiences the same or different? 86.169.184.247 (talk) 13:48, 31 January 2014 (UTC)

To your follow-up question, there is an example photograph at this similar question in which SteveBaker was asked to stop posting unreliable information about his "pet subject". 84.209.89.214 (talk) 14:52, 31 January 2014 (UTC)

You mean the photograph here? I see a probable difference in intensity between the photograph and the real thing, due to the fact that my monitor cannot pump out a sufficiently bright light, but I do not see any obvious difference in colour (admittedly, I do not have the apparatus to hand at present to compare). What difference am I supposed to be seeing? 86.169.184.247 (talk) 21:36, 31 January 2014 (UTC)

The triangle covers every hue (angle from the white point) but not highly saturated colors (more distant from the white point). Highly saturated colors are pretty rare in the real world. It's also worth mentioning that the area outside the triangle is not nearly as large perceptually as it looks in these coordinates—see MacAdam ellipse. -- BenRG (talk) 07:59, 1 February 2014 (UTC)

To 86.169.184.247, yes the photograph of a sodium flame. Its color reproduction is inadequate when compared with an actual sodium flame. Similarly, I challenge anyone to show a color-faithful photograph or video filmed under ordinary (not high pressure) sodium street lamp illumination. The qualified adequacy of additive and subtractive triple-primary color production processes in photography, printing and television encourages a simplistic assumption about human trichromacy, rather like Brahe's Tychonic system could be promoted as adequate for most astronomic purposes. Unfortunately for those who claim that 3 primary colors on your monitor can reproduce any color (having themselves perhaps never looked properly at the rainbow's spectrum or understood why they need to read an article such as Gamut) or claim that God's scripture forever obviates Heliocentrism (not caring to look at what Galileo could see through his telescope or perhaps just too fond of being adulated as Pope instead of plain Maffeo Barberini), scientific understandings neither of color vision nor of cosmology can be stifled for long by bigotry, itself a product of ignorance that should be out of date. 84.209.89.214 (talk) 15:09, 1 February 2014 (UTC)

Erm, well, it's true that triple-primary systems can't reproduce every color, but I don't think it has cosmic significance. Even cheap digital camera sensors can distinguish all of the colors that the human eye can, including the super-saturated colors, with only three color filters. The problem is that reproduction is harder than detection, not that human technology is inferior to biological technology. The mistake that many people (such as Steve) make is thinking that detection and reproduction are the same. -- BenRG (talk) 22:18, 1 February 2014 (UTC)

I discovered something interesting the other day: that digital cameras can detect the light from a TV remote control (maybe "everyone" knows this, but I didn't). Funny thing though, when I tried it, it looked white on the camera screen. Why doesn't it look a deep red? 86.161.61.104 (talk) 18:27, 2 February 2014 (UTC)

A digital camera sensor has (simplified) three layers: an infrared-blocking filter, the Bayer filter, and the sensor itself. The sensor is sensitive across a wide frequency range from the infrared to the blue-violet range; sensor elements are made color-specific by the filters in front of them. The dyes of the Bayer filter only permit light of the appropriate color (red, green, or blue) through within the visible range, but in the infrared range, they may be clear -- the camera manufacturer doesn't really care, because the IR-blocking filter keeps most of the IR out. Your remote control looks white because the IR LED is bright enough to shine through the IR-blocking filter, and is of a frequency that none of the color-filter dyes blocks, so it activates all sensors regardless of what color they are. --Carnildo (talk) 02:47, 5 February 2014 (UTC)

Well, there is a certain kind of flower that grows along the banks of the Lehigh River which I recall is so intensely red as to ... defy description. It seems to shimmer with an inconstant color, as if the eye is unable to sustain an understanding of it; it is as if it were a hole in the cosmos through which one could peer to some other universe where the sole commandment was "let there be red!" Unfortunately, the time I was there I ... lost track of the one I'd taken, meaning to look up what it is, but I was very much impressed, and it doesn't show up in RGB. Wnt (talk) 21:42, 31 January 2014 (UTC)

Gosh! 86.169.184.247 (talk) 21:59, 31 January 2014 (UTC)

Err. Were there any magic mushrooms growing close by?--Aspro (talk) 00:43, 2 February 2014 (UTC)

If so you want to stay away from them 'shrooms, as they too can open the door into anther universe, where one realizes that even your worst enemy is a friend – and that is not the American-Way. After all, it would mean there is no one anymore, to go to war with! That would not go down very well with the defence industry, that provides so many of our citizens with employment and health-care insurance.--Aspro (talk) 01:02, 2 February 2014 (UTC)

From a theoretical perspective, your ribbing of Wnt is not necessarily a safe bet. The CIE colour space does show scope for colours along the red-purple-blue trajectory that may stimulate the green receptors less than anything a screen could do (i.e. to have a more saturated colour). In nature, it is also possible to have fluorescence, in which a colour intensity is larger that 100% reflectance of a band of colours, which could lead to a super-intense colour not possible from pure reflectivity. From the graph, I expect that it would not be difficult to find cyans that are markedly more saturated than anything an RGB screen could produce. Colour-additive screens (of which RGB is an example) will have another quirk: they can produce the highest intensities precisely at hues where they cannot produce full saturation, as hinted by the three bright lines that can be seen radiating from the centre. —Quondum 16:29, 2 February 2014 (UTC)

Part of my understanding as to why RGB displays cannot reproduce the entire color space comes from my understanding of violet light. A blue phosphor emits light of a certain wavelength we call blue - it stimulates all cones to a certain degree even the red one. However violet light only stimulates the blue cone because it is beyond the sensitivity of the red and green receptors, while a blue phosphor is not. Please correct me if I'm wrong.  — TimL • talk 09:27, 3 February 2014 (UTC)

Incidentally, searching for monitors and "six primary colors" yields relevant material like [5] [6] [7] etc. It looks like making a bigger polygon is an idea that goes back a long way, though even the more recent refs still seem to by shying away from the extreme fringe of monochromatic cyan that rounds out the tip of the curve between 500-540 nm. Wnt (talk) 17:01, 4 February 2014 (UTC)

Effects of long, long term exposure to radiation on human body/skeleton

Hello dear Wikipedians.

For reasons of fiction, I wish to inquire what might be the effects of 2,000, 5,000 and 10-20,000 years worth of cosmic radiation to a human body. More specifically, a deceased body kept in a glass coffin of sorts, floating idly far away from our solar system. Do I assume correctly that the skeleton does not simply remain, but might alter in certain ways due to the radiation? And what about the rotting process? Anything left as a waste product inside this confined space?

I thank you very much for any educated guesses.

213.104.126.183 (talk) 02:57, 31 January 2014 (UTC)

A dead body in deep space (which is what I assume you mean by "far away from our solar system") would become very, very cold and freeze solid. At that point, most normal decay processes would essentially stop. If the coffin is not air tight and the body is exposed to vacuum, then volatile compounds (like water) would gradually be lost to space. Dragons flight (talk) 04:53, 31 January 2014 (UTC)

Cosmic radiation is a little different, but basically you're asking about food irradiation. There's something about meat being irradiated so that you can keep it at room temperature around 70 kGy, which is a lot compared to figures I'm seeing in radiation carcinogenesis in past space missions of 0.12 mGy/day (though to be honest, I didn't look very closely - why bother, if you want you can make your future space shielding better or worse than the missions). So I think you get that in 550 000 000 days, more than a million years? I also didn't look into whether the flavor of heavily irradiated meat is noticeably different, but it should at least look like a corpse. Wnt (talk) 06:21, 31 January 2014 (UTC)

Unless it happens to drift near a supernova or a pulsar (or, God forbid, a quasar) -- in which case it would be charbroiled before it got to the other side. 67.169.83.209 (talk) 06:39, 31 January 2014 (UTC)

Mmmmmmm. After your first decade or so marooned on floating space junk eating algae recycled from your body waste, you'd be amazed how a charbroiled corpsicle gets your appetite going. :) Wnt (talk) 15:37, 31 January 2014 (UTC)

My back-of-the-envelope estimate shows it only takes about 15 minutes for a room-temperature body to radiate enough heat to reach freezing temperature, so no traditional decomposition should occur. Katie R (talk) 14:57, 31 January 2014 (UTC)

Given the time span mentioned, some type of nuclear transmutation may well occur.--Auric talk 19:39, 31 January 2014 (UTC)

OP here. THank you for your responses. I see the consensus is a quickly frozen body, outwardly largely similar despite radiation. Nothing spectacular happening anywhere, then? Colour of the skin, structure of the eyes? 213.104.126.183 (talk) 02:43, 1 February 2014 (UTC)

Well, there could be other aspects of being in space that would have more dramatic effects. For example, depending on the equilibrium temperature the body reaches, it may be warm enough for ice to sublime, leading to freeze drying. I really have no conception what freeze drying an eye does, but it might be visually interesting. Also, if it is in a coffin that sunlight can penetrate, especially high frequencies, the body would be affected pretty substantially by solar bleaching effects. And if the orbit (including just the coffin rotating slowly in the sun) causes the body's temperature to increase and decrease periodically ... I'm not sure what would happen, I just think about what the seasonal temperature changes and frost heaving do to the roads. Wnt (talk) 05:38, 1 February 2014 (UTC)

Center of mass of the sun-earth system

Which of the following two statements is correct?
1) Earth moves around the center of the sun.
2) Both, earth and sun, moves around their common center of mass. 27.62.119.215 (talk) 06:49, 31 January 2014 (UTC)

Neither. There are other planets in the solar system too. AndyTheGrump (talk) 07:18, 31 January 2014 (UTC)

If we ignore other planets, then the two items orbit about a barycenter. In the case of the Earth-Sun pairing, that barycenter is still within the Sun, but not at it's center (slightly offset towards the Earth). StuRat (talk) 07:21, 31 January 2014 (UTC)

Two astronomical bodies orbiting a barycenter inside one body (not drawn to scale).

I should have used earth-moon system instead of sun-earth system. I think you have got what I was asking. In the article Barycentric coordinates (astronomy), it is given that - "When a moon orbits a planet, or a planet orbits a star, both bodies are actually orbiting around a point that is not at the center of the primary (the larger body). For example, the Moon does not orbit the exact center of the Earth, but a point on a line between the center of the Earth and the Moon, approximately 1,710 km below the surface of the Earth, where their respective masses balance. This is the point about which the Earth and Moon orbit as they travel around the Sun."
Do moon and earth orbit their common center of mass in circular orbits or in elliptical? 182.66.191.224 (talk) 07:45, 31 January 2014 (UTC)

Perfect circles don't really occur in these situations, but in the case of the Moon's orbit the distance from the earth varies roughly between 405,000 and 363,000 km, so the orbit is noticeably non-circular (it has an orbital eccentricity of 0.0549). The same should be true for the Earth's orbit, because the ratio between the Earth's and the Moon's distances to their center of mass is by definition a constant. - Lindert (talk) 09:36, 31 January 2014 (UTC)

According to the classical picture of an atom, an electron orbits the nucleus. In this case also, is it true that both (proton and electron in hydrogen atom) orbit around their common center of mass? 106.216.120.89 (talk) 11:39, 31 January 2014 (UTC)

Yes, the principle is the same. Do note however that in an elliptic orbit the center of mass is not actually located in the center of the ellipse, but in one of the two focal points. - Lindert (talk) 12:11, 31 January 2014 (UTC)

If you mathematically treat an electron like a ball and the nucleus like another ball (i.e. the model of Hantaro Nagaoka), then yes, the same physics equations would apply. However, there's lots of good reasons why an electron should not be treated like a ball orbiting a bigger ball, not the least of which is that the Larmor principle states that any accelerating electric charge always sheds energy in the form of photons. Since a revolution is a form of acceleration, consider an atom where an electron was truly orbiting a nucleus. Said electron would be continuously shedding energy, slowing down and spiraling in towards the nucleus. Since electrons don't do that, the model that says they do "orbit" the nucleus like a planet does must be wrong. That sort of inconsistency is partially what led to the quantum mechanical model of the atom. --Jayron32 03:46, 1 February 2014 (UTC)

Well, there are Rydberg atoms in which an electron can actually be resolved as a particle well separated from the nucleus. I recall asking about them earlier and ironically enough, as I recall, these are actually superpositions of a wide range of quantum states in order to assemble the observed point particle. (Measuring the position scrambles the momentum, and measuring momentum would scramble position, per the Heisenberg uncertainty principle) [8] Still, it should be clear that between discrete emission events and observations, a macroscopically separated electron will orbit by Kepler's laws. Also, note of course both particles do orbit symmetrically about the center of mass, in ellipses; they're just different ellipses. If you have two identical planets orbiting elliptically, one on the left, one on the right, the center of mass is the right focus of the left ellipse and the left focus of the right ellipse. Wnt (talk) 05:28, 1 February 2014 (UTC)

Sort of. The solutions to quantum mechanical stuff always resolves to classical physics in the macroscopic world. That is, you can use quantum mechanics to describe, say, the trajectory of a cannon ball and get results that match observed data for its flight. But classical physics works also for that situation and is simpler. That simple fact means there must be some scale where the transition between "where quantum mechanics applies but classical mechanics doesn't" and "where quantum mechanics and classical mechanics both apply, but where classical mechanics makes more sense to use cuz it's easier" occurs. The Rydberg atom lies just at that point: the electron is so weakly bound to the nucleus that its behavior matches that of a simple "small sphere orbiting a larger sphere" one would predict using simple Kepler physics. But it's basically a situation invented just to explore the physics at that peculiar scale. For normal atoms (i.e. what you and I and everything are made of), classical physics doesn't work well (i.e. the Larmor problem noted above: classically, electrons should spiral into the nucleus). --Jayron32 05:41, 1 February 2014 (UTC)

"ironically enough, as I recall, these are actually superpositions of a wide range of quantum states in order to assemble the observed point particle" – it's a single state, but that state is a sum of a lot of energy eigenstates (states of definite energy). The reason is simply the uncertainty principle: if the electron's position within the orbit is not completely indeterminate then its orbital energy must be at least somewhat indeterminate. This applies to macroscopic objects too, in theory. -- BenRG (talk) 08:47, 1 February 2014 (UTC)

I'd say that what breaks down at atomic scales is the Larmor formula, not the idea that electron orbitals are orbits. I suppose it's just a matter of language. Regardless, the center of mass of a hydrogen atom is about 1/1836 of the way from the nucleus to the electron, or about 1/1836 of an angstrom, which is significantly larger than the proton's radius of around 1 fm (1/10000 of an angstrom), so the "orbital fuzziness" of the nucleus is quite large, larger even than the fuzziness of my estimate. -- BenRG (talk) 08:47, 1 February 2014 (UTC)

Calories in medicinal clay

I have long wondered about Geophagy, and whether medicinal clay has any caloric value. I can't find even a mention of calorie content in either article. Can someone direct me to a method to calculate this? The calorimetry article is too technical.--Auric talk 20:18, 31 January 2014 (UTC)

I don't think the body is realistically going to break down silicates, let alone extract energy from changing their form. There are cases in which bomb calorimetry is wrong: for example, it would measure calories in dietary fiber that you don't actually extract. If your interest is in whether energy can theoretically be extracted from it, we could continue, but if the calorie count in a food sense is what you're after I think you should write it off. (Of course, if the clay is impure or mixed with flavorings, it could have calories; also, its use by parrots in absorbing alkaloids and the medical side effects listed in the medicinal clay article also suggest the potential to have somewhat negative effective calorie count by hindering absorption of other food) Wnt (talk) 21:50, 31 January 2014 (UTC)

Realistically, your body only gets food energy from about 6-7 different classes of compounds. Silicates are not one of them. Other than the "big three" of protein, carbohydrate, and lipids, there's stuff like ethanol, some dietary fiber (which does give some food energy), and a few other classes of compounds. There's really nothing in clay aside from tiny bits of rock, and you can't extract food energy from that. There may be some dietary minerals in there, but that's about it. --Jayron32 03:39, 1 February 2014 (UTC)

Orbitally Rearranged Monatomic Elements

Why is there not even a stub? Seems quite odd to not even have an entry.. — Preceding unsigned comment added by 50.78.98.154 (talk) 22:41, 31 January 2014 (UTC)

In order for a fringe theory to warrant an article, it must be notable, irrespective of whether it is true or untrue. Nimur (talk) 23:02, 31 January 2014 (UTC)

Articles have been created on the topic, but the overwhelming consensus each time has been to delete them. For the discussions about why they were deleted, see WP:Articles for deletion/Orbitally rearranged monoatomic element and WP:Articles for deletion/Orbitally Rearranged Monoatomic Elements. Red Act (talk) 01:24, 1 February 2014 (UTC)

Is this topic really not notable enough for a Wikipedia article? 86.169.184.247 (talk) 04:33, 1 February 2014 (UTC)

Really. See, Wikipedia will cover bullshit, but only when enough people have written about the bullshit as bullshit. See, for example, flat earth, or homeopathy. Those are two examples of well documented bullshit. This bullshit here is not even notable as bullshit. That is, it isn't receiving even notice for being bullshit, at least of the level of coverage we'd expect to support a Wikipedia article. --Jayron32 04:40, 1 February 2014 (UTC)

I understand the difficulty of writing about a topic if reliable sources do not discuss it. However, there seems to be a pretty extensive crackpot literature on this topic, and I, for one, would appreciate a rational Wikipedia article about it. 86.161.61.104 (talk) 20:50, 2 February 2014 (UTC)

It there is only 'crackpot literature' on a subject, it doesn't meet our notability guidelines, and a lack of non-crackpot sources would make writing a policy-compliant article impossible. 'Crackpot' sources are only reliable for the authors' opinions (rarely notable, and in consequence of little relevance to an encyclopaedia), and the lack of non-crackpot sources would oblige us to engage in original research to demonstrate the obvious crackpottery of the idea. AndyTheGrump (talk) 21:09, 2 February 2014 (UTC)

In my opinion crackpot coverage should contribute to notability. 86.161.61.104 (talk) 23:53, 2 February 2014 (UTC)

Hmmm, seems like this takes this guy apart like a frog in a blender. The funny thing is though, the original patent doesn't seem that far-fetched as a concept. I mean, we know that the transition elements have orbitals in different shells at very similar energies, such that the precise electronic configuration of an element is not a trivial thing to guess but had to be determined empirically. Why shouldn't there be low-energy excited states of transition elements that have notably different chemical properties? And could any of them turn out to be stable long enough to be isolatable in a laboratory? Wnt (talk) 05:59, 1 February 2014 (UTC)

@Wnt: – To be of any significance, it should not be purely unsubstantiated conjecture. We know that in any substance in thermodynamic equilibrium, all possible states of a substance are present in abundances according to the respective energy levels, which kind of trashes that idea, unless there is an exceptional mechanism blocking transitions to and from other states so that it takes very long to reach equilibrium under normal conditions. Although some transitions are "forbidden", thus slowing certain modes of decay, to have certain orbital configurations being effectively isolated from excitation to or decay from any other available modes under normal room-temperature conditions in such a complicated system as a transition element would be truly phenomenal. To have these configurations being stable yet to be chemically very distinct takes this even further into the realms of impossibility, since these two properties are pretty much incompatible. —Quondum 22:21, 2 February 2014 (UTC)

Of course - I realize we're talking about fringe science here, not anything remotely supported. But when evaluating fringe science, the mere idea that something might even conceivably not be completely and absolutely impossible is entertaining, because then we get to ask: how do we know for sure? Wnt (talk) 23:27, 2 February 2014 (UTC)

You apply the Russell's teapot variant of Occam's razor, and then you go home and get a good night's sleep. It's not my responsibility to respond to every evidence-free assertion that someone made up. TenOfAllTrades(talk) 00:37, 3 February 2014 (UTC)

At an investigative level, naturally everything should be entertained. But at a reference level, no. Also, answering the question only becomes interesting when we feel there may be some path to a better understanding, and I discern none. In any event, in the original context framed by the OP, that is to say, whether this warrants an article in WP, I think that the WP principles and guidelines give a pretty unambiguous "no". WP is not a secondary source; we are editors, not journalists. —Quondum 00:53, 3 February 2014 (UTC)

I didn't see reason to make an article from this, but it has nothing to do with the idea's scientific validity (or lack thereof). After all, we do cover events in a journalistic sense, e.g. Power Balance. Indeed, in the age of Bitcoin, we have progressed (alas) beyond a narrow rationalistic mind-set, to understand that things can be valuable solely for being valuable; it doesn't matter if they're useful, and so by extension, it doesn't matter if they work. For example, just because a company promises that it can build a thorium powered car that runs forever on a lump of metal the size of a pack of chewing gum, or plans to send people on a one-way trip to Mars, doesn't mean that it is a bad investment. Possibly in a thousand years the fantastically wealthy heirs of their founders will still be making money by investment, public speaking engagements, posters, franchise agreements, fan websites and all sorts of related merchandising, while their scientific detractors have long since been adjudicated for debt, implanted with brain chips, and set to work forever sweeping their floors (solely as a status symbol, of course). Wnt (talk) 17:09, 4 February 2014 (UTC)