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August 30

Recycling

Is there an example of a recycling plant that employs destructive fractional distillation under a reducing hydrogen atmosphere? I know of examples that separately employ fractional distillation, and plasmification, but not one that combines both. Plasmic Physics (talk) 04:15, 30 August 2014 (UTC)

The ideal cases in mathematics, physics and chemistry

Does the ideal cases in mathematics, physics and chemistry are been always right? The ideal cases in mathematics, physics and chemistry are been always a regularity or a paradox?--Alex Sazonov (talk) 05:18, 30 August 2014 (UTC)

I think you're asking whether the theoretical answer is always the real-world solution. That would be more common in math, although there are also many wrong answers provided by math, along with the correct ones, such as negative square roots that don't apply to a real-world case. In science there's more often a difference between the theoretical and observed. For example, the observation of the universe expanding at an ever increasing rate was completely unexpected by theory. StuRat (talk) 05:27, 30 August 2014 (UTC)

What force(s) would be causing such acceleration? ←Baseball Bugs ^{What's up, Doc?} carrots→ 05:33, 30 August 2014 (UTC)

Bugs, see accelerating universe. Staecker (talk) 14:04, 30 August 2014 (UTC)

Thank you StuRat. I’m sorry for my next question, but I want to better understand you. Does the formulas of ideal cases in mathematics, physics and chemistry are been always right?--Alex Sazonov (talk) 05:46, 30 August 2014 (UTC)

In general in mathematics formulae are always exactly right, even when something is an approximation it is a correct approximation otherwise there is an error in the mathematics. In general in physics and chemistry everything is wrong because there is always something left out or the theory isn't absolutely certainly true of the real world. This is a problem of ontology and the difference between existence and truth in mathematics as opposed to physics or chemistry. Dmcq (talk) 07:02, 30 August 2014 (UTC)

Is mathematical scientific doctrine is not absolute in the sciences, that is, what the mathematical scientific doctrine does not provide the identity of theory and practice in the sciences, including the practice of scientific research?--Alex Sazonov (talk) 12:05, 30 August 2014 (UTC)

I think there are several different aspects here. But at the heart there is a serious philosophical debate. See The Unreasonable Effectiveness of Mathematics in the Natural Sciences. --Stephan Schulz (talk) 12:11, 30 August 2014 (UTC)

Thanks. Does the scientific knowledge of the world in mathematics is always absolute or not absolute? Does the mathematical of the cybernetics is been always right?--Alex Sazonov (talk) 12:35, 30 August 2014 (UTC)

Have you read and tried to understand the article pointed to by Stephen Schultz in the twenty minutes between him writing his reply and your response? Why do you expect anyone to be able to give you any better response than is already given? Dmcq (talk) 13:50, 30 August 2014 (UTC)

What practical and theoretical mathematics always had ambiguity? The mathematics always is been a much exact science!--Alex Sazonov (talk) 15:17, 30 August 2014 (UTC)

I think, Norbert Wiener always supposed that practical decisions in mathematics always had higher values than the theoretical decisions, as practical decisions in mathematics always explained something that is not able to explain the theoretical mathematics.--Alex Sazonov (talk) 15:55, 30 August 2014 (UTC)

The idealism concerned in the question is the conviction that scientific method must build objectively stated unambiguous theories that have reliable predictive power; it is satisfactory demonstration of predictions that distinguishes theories from hypotheses. The scenario for fulfilment of a prediction is the ideal case. In chemistry, formulae for reactions must assume that the ingredients are pure and in analytical concentrations; in physics, calculation of a two-body planetary orbit (Kepler) must assume that every other object in the Universe has zero gravity; in mathematics nothing exists unless it is designated and nothing designated may vary unless it is declared to vary in a more (Algebraic number) or less (Transcendental number) restricted way. Use of ideal cases

• is relevant for exposition and understanding of scientific theory
• is necessary to show the scope of applicability of a principle, accepting the "paradox" that the ideal cases are generally unachievable
• leads to amiable parody such as "Consider a Spherical cow in a vacuum...".

Idealized cases do not however relieve the intellectual from studying or the investigator from investigating more demanding real-world complexities, because hanging on to Naïve physics offers only the intellectual stagnation of Pope Urban VII confronting Galileo. The square root of -1 is formally an imaginary mathematical unit and far from being a "wrong answer" it is fundamental to Complex number calculations which have had serious practical applications since the 17th century (Tartaglia). "Absolute truth" is a commodity of belief systems that is inaccessible to scientific analysis, is a theme in philosophy that is accessible to scientists though not to science, is not yet claimed by responsible chemists or physicists, and is only ever delineated provisionally by mathematicians. 84.209.89.214 (talk) 15:58, 30 August 2014 (UTC)

Is identity in mathematics always been absolute? If A always is not been equal to B, is B always not been equal to A, or thats is not been right? I think, it always is been a much exact, it is been mathematics.--Alex Sazonov (talk) 17:30, 30 August 2014 (UTC)

Time does not enter into math unless it is deliberately introduced as a variable (often as t seconds). A and B do not exist in a mathematical proof until they are designated (invoked); expressions like A=B become absolutely true from the moment they are stated; an operation A+B can give a result C which is similarly true from the moment it is stated because the operator "+" has been defined earlier. Values that the mathematician assigns persist only as long as needed to complete a calculation; one may turn the page of a math textbook and then find A, B and C used differently. A few constants such as pi have unchangeable values. There is a particular meaning of Absolute value which is the distance from zero of a value but I assume you don't ask about that. 84.209.89.214 (talk) 18:40, 30 August 2014 (UTC)

I'm trying to prove that mathematics consists of identities and not of mathematical hypotheses have (had) no practical mathematical solution, I believe that all of mathematics is presented mathematical identities always have mathematical solutions, so I am a supporter of absolute mathematical identity as the absolute accuracy of mathematics.--Alex Sazonov (talk) 19:53, 30 August 2014 (UTC)

Sadly, you need to read Gödel's incompleteness theorems...and if you have the time and patience, Gödel, Escher, Bach by Douglas Hofstadter. Mathematics is (for sure) always going to be incomplete. There are mathematical statements out there that can never (even in principle) be either proved or disproved. SteveBaker (talk) 20:44, 30 August 2014 (UTC)

Umm, let's be a little careful here. The theorems say that no fixed formal theory, with appropriate technical stipulations, can answer all mathematical questions. They don't say that there's any particular statement that can never be proved or disproved by any theory. --Trovatore (talk) 08:01, 31 August 2014 (UTC)

I think that, a practical method of mathematical decision of a mathematical problem always had generates a theory of mathematics! Does it make sense to use in scientific knowledge the mathematical theories (hypotheses) which had no practical solutions?--Alex Sazonov (talk) 07:14, 31 August 2014 (UTC)

Exterminating virtual particles

I understand that virtual particles are very common in modern physics, but... my mind rebels against them. I mean, consider the Casimir effect. The plates are drawn together by the lack of virtual particles with certain frequencies that can't exist due to the conductive plates around them. It seems simple enough, except... suppose the plates weren't conductive, or were only mostly conductive. Then I'm supposed to believe that the vacuum is a sea full of an infinite variety of virtual particles, and out of all that mind-boggling density of imaginary stuff, the ones that measure the plates' conductivity are the ones that don't exist, even as "virtual" particles. Do I have that right? Whereas (as the article says) simply looking at the effect as a Van der Waals force, based on (I assume) the very clear uncertainty of the position and momentum of the real electrons in the metal plates, seems incredibly more straightforward.

Anyway, has a reputable authority tried to lay out a physics in which each and every proposed virtual particle has been exterminated from consideration, whether for mediating the Coulomb force or Hawking radiation or any of the dozen other things mentioned in virtual particle, relying only on honest-to-God particles? Wnt (talk) 17:46, 30 August 2014 (UTC)

This question is near the line between physics and metaphysics - Horror vacui (physics), The World (Descartes) (as we don't have an article specifically on the Cartesian Plenum), Vacuum energy and Dirac Sea might be useful further reading. The experimental observation for which we need to save the appearances is that particles interact with each other in a vacuum (a real vacuum that one can produce with a vacuum pump). The alternatives to virtual particles are the acceptance of action at a distance without any physical mediation, or the view that the vacuum isn't empty, but contains (an infinite amount) of a substance through which particles interact. All three have their metaphysical disadvantages, and all three give us theories that explain the real world. Tevildo (talk) 19:46, 30 August 2014 (UTC)

It is clear that virtual particles provide a useful framework for calculating a variety of very real phenomena. However, it is not necessarily the case that they really exist as such. Allow me to draw a very crude analogy. Suppose a small boat is sitting on a pond, and somewhere else on the pond you drop in a stone. This generates ripples on the pond that cause the boat to move. Now suppose you couldn't see the water ripple, instead all you could see was the passing stone and the bobbing boat. You might imagine that the stone was sending out invisible particles that were hitting the boat. In a way, virtual particles are a bit like that. Virtual particle interactions can also be interpreted as fluctuations in a hidden higher-dimensional structure of spacetime, sort of like ripples on a pond, but in a space that incorporates the fundamental forces and standard model particles as an extension of the properties of space itself. Essentially, one can consider virtual particles as a sort of accounting gimmick that allows us to describe the complex ways that the various forces perturb the universe. Whether you actually imagine that we live in a complex sea of virtual particles rippling in and out of existence, or rather choose to imagine that we live in a complex and dynamic higher dimensional spacetime is essentially a matter of interpretation. Like the various interpretation of quantum mechanics the different points of view are more about philosophical interpretation than useful prediction. Dragons flight (talk) 22:05, 30 August 2014 (UTC)

I suppose there are other cases of this; for example, the "holes" in semiconductors are like this. But if you have a semiconductor with one random atom missing, and you look at the localization of a "hole" that is adjacent to it, I assume it doesn't actually look like an anti-electron, because I'd expect the probability pattern of the hole to reach up and around the physical hole in the structure whereas the electron would have no interest in embracing it. I wonder if virtual particles can lead us astray the same way. For example, in the infamous black hole information paradox, we uncritically accept that "virtual particles" are bringing information from nowhere out of the hole. Only... what if this is more virtual particle BS? What if really the paradox can be explained by simply discovering that we're looking at the uncertainty of the position and momentum of the particles that were falling in before they hit the horizon, which allows for a chance they really never did? Or the odds that they did go in the singularity, but tunneled out again. Or ... something. I'm not a physicist and I'm not trying to propound a theory here, just feel like what I'm being fed tastes off. Wnt (talk) 15:29, 31 August 2014 (UTC)

The paradox - again, we're really still in metaphysics, although this issue is potentially amenable to experimental resolution - depends on the principle of quantum determinism, that Laplace's demon can put any system back together again, even if it falls into a black hole. This may not be true in the first place (which is a question of pure metaphysics), but, even if it is, the mechanism by which the wavefunctions of the black hole's source particles are recovered doesn't have to involve virtual particles. Without knowing what goes on at the singularity, we can't say definitely that the wavefunctions are "destroyed" and have to be "recreated". They could persist through the accretion and evaporation process, as you suggest. Until the physicists come up with a testable theory, all we can do is check the maths is correct and doesn't contradict observation. Tevildo (talk) 19:10, 31 August 2014 (UTC)

The original Hawking radiation paper derived the result nonperturbatively (without virtual particles). He only mentioned virtual particles as a handwavy informal picture of what's going on. It can certainly happen that no one knows any way to get a handle on a difficult problem except by some approximation method, and the result can have features that look like real physics but are actually artifacts of the approximation method. If the approximation involves virtual particles then you would be misled by virtual particles, in a sense. But those sorts of problems are unavoidable when you're doing original research. Professional particle physicists understand that the nonperturbative physics is what matters; I don't think they overvalue virtual particles the way pop-physics books do. -- BenRG (talk) 23:04, 31 August 2014 (UTC)

Hmmmm, to me it sounds as if Hawking was indeed saying something vaguely similar to what I was suggesting all along, from the first paper in 1975, the only difference being that his version was mathematical, meaningful and coherent. :) What I wonder, though, is if the "tunneling" going on in any way would imply that when matter is eaten, matter would outweigh antimatter in the radiation, i.e. that the notion of taking a mini black hole and stuffing it with a matter beam to convert it into energy might be too good to be true. Wnt (talk) 05:52, 1 September 2014 (UTC)

I'm not sure what you're saying, but there's no "tunneling". The Hawking radiation comes from outside the horizon. -- BenRG (talk) 22:05, 1 September 2014 (UTC)

Elevation and temperature

At what elevations do temperatures start to change significantly? 500m? 1000m? Etc — Preceding unsigned comment added by 90.192.117.124 (talk) 20:02, 30 August 2014 (UTC)

See Tropopause, Atmosphere of Earth, and (perhaps) Atmospheric temperature (although that last article isn't very good). 500 m and 1000 m are still comfortably within the troposphere - the tropopause (where temperature _stops_ changing significantly) is at about 10000 m. Tevildo (talk) 20:10, 30 August 2014 (UTC)

To answer your question literally, temperatures _start_ changing significantly at zero elevation. The temperature at the top of a medium-sized building (50 m / 150 ft) will be about 0.5 C lower than at ground level, which will be noticeable to most people. See lapse rate. Tevildo (talk) 20:35, 30 August 2014 (UTC)

You said elevation (i.e. height above sea level) and not altitude (i.e. height above local ground level). Assuming you really want to know about elevation related changes, then the surface elevation lapse rate is about 3 degrees C per km of elevation change in environments with slowly changing elevations. This is significantly less extreme than the about 6.5 degree C / km atmospheric lapse rate that one experiences from simply going up in altitude. The difference is related to the role of solar heating in setting the conditions at the ground surface. Dragons flight (talk) 21:27, 30 August 2014 (UTC)

A minor correction - altitude is also the height above sea level, which (unlike elevation) may be different from the height above ground level. Height above ground level is just "height" (or QFE). Tevildo (talk) 21:52, 30 August 2014 (UTC)

In my area of climate science, "altitude" is nearly always a synonym for "height above ground level" also known as the "absolute altitude". As far as I know, it is only people in aviation that insist in using "altitude" to generally mean height above sea level. Dragons flight (talk) 22:16, 30 August 2014 (UTC)

By way of evidence that "altitude" can be used to mean "elevation", I submit this. It'd be in England. --65.94.51.64 (talk) 05:50, 31 August 2014 (UTC)

I'd just submit altitude. --jpgordon^{::==( o )} 04:45, 2 September 2014 (UTC)

August 31

Metabolization of trans fats

Small amounts of ethanol naturally occur in our food, thus we have evolved a way to metabolize those small amounts which would otherwise be harmful. Distillation of alcohol, however, allows us to drink way too much alcohol to metabolize before it does damage.

Similarly, small amounts of trans fats naturally occur in our food, but the food industry has found a way to add massive quantities of artificially created trans fats. So, then, my Q is if our bodies have evolved a way to metabolize small amounts of trans fats before they cause damage. For example, is 0.1 g of trans fats 1/100th as harmful as 10 g, or not harmful at all ? Or, put another way, would you do as much damage to your body eating 0.1 g of trans fats every day, for 100 days, as you would if you consumed 10 g in one day ? If possible, I'd like to know just how much we can metabolize safely in a day. If "trans fats" is too broad of a category, let's restrict it to partially hydrogenated vegetable oils.

The reason I ask, BTW, is that some restaurants have started listing tenths of a gram on their nutrition info for trans fats, and I don't quite know what to do with that info. Before, if it had 1 gram or more, I would skip that item. If it said 0 g I would eat it. But now I see 0.1 g, for example, and don't really know if that's safe to eat or not. StuRat (talk) 02:26, 31 August 2014 (UTC)

I'd say eat it, go for a good walk afterwards, and stop worrying. The worry is more likely to kill you. HiLo48 (talk) 02:30, 31 August 2014 (UTC)

That would be blatant medical advice. Over the past century, the geniuses who came up with the notion of putting artificial chemicals that superficially resemble lard into the food supply have managed to kill millions of people, and that really does matter. The risks might be "relatively small" (I just saw a figure of +7% risk of stroke per gram per day in men) but they are increases in risk for some of the most common causes of death. Wnt (talk) 12:02, 31 August 2014 (UTC)

For part of your question, the answer is that "trans fat" isn't all one thing that acts one way, just as "fat" isn't. Even if you suppose lipids are cleanly broken up into fatty acids in a fungible way, each type of fatty acid has different properties; they are precursors to hugely important compounds like prostaglandins, endocannabinoids, and many many others. Each of those classes of compound is made up members with different chemical formulas that are produced from one specific fatty acid or another. If you look at [1] and [2] you'll see this kind of study, but not much is known; it appears though that the natural trans fats are much less harmful if harmful at all, presumably because the evolution of metabolism has taken them into account. Generally speaking, if you climbed on board an alien spaceship and managed to get a machine to pump out bars of "generic food" made up of all the right elements in a vaguely right proportion, it wouldn't be healthy eating. Catalytically altering fat is very much like that, only among a more restricted class of compounds.

In a quick search I didn't find data about consumption of limited amounts of trans fats. It would be next to impossible to control for in a human population, and it would make for an immense animal study in order to have the necessary statistical power, so I can see the difficulty. Biology is never simple though - it's impossible to say a priori whether a small amount is as bad as a large amount, or proportional, or harmless -- for all I know some sort of hormesis could apply. But I wouldn't bet on that. Wnt (talk) 12:02, 31 August 2014 (UTC)

Thanks, but remember, I added "If 'trans fats' is too broad of a category, let's restrict it to partially hydrogenated vegetable oils". StuRat (talk) 12:13, 31 August 2014 (UTC)

Well, my point is that the natural trans fats in food are not partially hydrogenated vegetable oils. Wnt (talk) 15:16, 31 August 2014 (UTC)

OK, that would seem to imply that any ability we've evolved to deal with natural trans fats would not help in the metabolization of PHVOs, and hence any amount is harmful. StuRat (talk) 19:05, 31 August 2014 (UTC)

I would not eat it unless it was a very rare and special occasion. Trans fats are cumulative killers. Each little bit does a tiny bit more damage. I don't believe it works like Radiation hormesis but rather like the Linear no-threshold model. Ariel. (talk) 02:37, 1 September 2014 (UTC)

You're free to guess that, but biology doesn't know theory. It is possible, for example, that eating a tiny amount of trans fat would induce cytochrome P450 enzymes that break down some sort of metabolic products that end up accumulating, leaving you better prepared for some point over the next week when you gulp down grams of the stuff in a mislabelled or unlabelled product you didn't know about. On the other hand, that same sort of activity might increase the oxidative stress on something and cause toxicity well out of proportion to the quantity. The only real advantage of the linear no-threshold model is that it's sort of an average among the possibilities. Wnt (talk) 17:44, 1 September 2014 (UTC)

What type of Hair styling cosmetic doesn't contain any lipids\Hydrophobic materials?

I want use something which is both easy to get, and doesn't contain any lipids\Hydrophobic materials and thus leaves the hair easily in wash... Any suggestions? Thx. Ben-Natan (talk) 03:49, 31 August 2014 (UTC)

Lipids should be easy enough to wash out, provided you use shampoo (not a shampoo/conditioner combo). If you had something that rinsed out in just water, then rain would leave your hair a mess, too. StuRat (talk) 04:23, 31 August 2014 (UTC)

Anything else?, Does Gels or Mouses typically contain\should contain Lipids? Ben-Natan (talk) 22:11, 31 August 2014 (UTC)

Lead acetate is the mot common men's hair coloring. It is certainly not easily washed out, although the instructions say not to shower for qt least four hours after use.

Does knowledge is been verb in English language?

Does knowledge is been verb in English language?--Alex Sazonov (talk) 07:55, 31 August 2014 (UTC)

As I know, the knowledge is been the verb forming, which is been a verbs saying. Is it right?--Alex Sazonov (talk) 08:30, 31 August 2014 (UTC)

Are you asking if "knowledge" is a verb in English? If so, then the answer is that "knowledge" is a noun. The verb is "to know". The words "is been" don't occur in English in that order. You can ask "is knowledge a verb", and you need to omit "been" in your sentences. Dbfirs 08:35, 31 August 2014 (UTC)

Here are references for your English language questions:

• WP:RD/L - the Wikipedia Language reference desk. Your questions will be seen by language specialists who may not look at this science desk.
• [www.onelook.com] - a site that checks a large number of dictionaries. You can try it now.
• [3] - etymology is the study of the origin and development of words. You can try it now.
• There is also an Wikipedia article about Knowledge. 84.209.89.214 (talk) 09:12, 31 August 2014 (UTC)

Some nouns and adjectives will are derived from verbs, is it not this the case? In my language mind the knowledge is been discovery process.--Alex Sazonov (talk) 08:58, 31 August 2014 (UTC)

Yes nouns and adjectives can be derived from verbs, and this is exactly what we have here: the noun "knowledge" is derived from the verb "know". "Knowledge" as a verb is obsolete, but has been used historically in the English language. The Oxford English Dictionary gives six distinct senses of "knowledge" as a verb, these have mostly been replaced with "acknowledge". The most recent attestation given by the OED is from 1797: "If any ecclesiastical person knowledge a statute merchant or statute staple, or a recognizance in the nature of a statute staple." (Burn's Eccl. Law (ed. 6) III. 204) - Lindert (talk) 13:50, 31 August 2014 (UTC)

Lindert, Thank you very much!--Alex Sazonov (talk) 14:12, 31 August 2014 (UTC)

So it is correct to say that "knowledge" has been used as a verb, but is not used as a verb in current English. The verb "to be" in English is usually strong enough to stand on its own (but occasionally needs reinforcing with another verb). It never appears with two different tenses together (like "is been" or "will are"). Dbfirs 14:28, 31 August 2014 (UTC)

The commonest way to derive a noun from a verb is to add the ending -ing which creates a Gerund that can function as a noun. The verb to know makes the gerund knowing which can be used as a noun (as in Knowing two languages is useful). There are many similar verb/gerund pairs such as to paint/I like painting, to write/I like writing, to build/I like building. I will emphasize that Dbfirs is correct, "knowledge" is used as a noun and never as a verb in modern English. The past tense of "to be" that you should know is "Has knowledge been a verb? - Yes, it has been a verb but it is not a verb today". 84.209.89.214 (talk) 14:45, 31 August 2014 (UTC)

I been spouse that, the verb been always has the perfect form of the verb in all tenses.--Alex Sazonov (talk) 05:41, 1 September 2014 (UTC)

You might wish to read the conjugation section of Wiktionary's entry on the verb. Dbfirs 07:39, 1 September 2014 (UTC)

Thank you! Do I understand correctly that the values of perfect verbs never change, and not to override by other verbs participating in the phrase?--Alex Sazonov (talk) 09:00, 1 September 2014 (UTC)

Does a perfect mirror violate the laws of thermodynamics?

A mirror that reflects 100% of the electromagnetic radiation directed towards it. I'm fairly certain this is impossible, but I just want to confirm that it violates the 2nd law of thermodynamics. ScienceApe (talk) 13:32, 31 August 2014 (UTC)

As I think that, the absolute mirror reflection which is been an absolute mirror effect will always had be possible only in the case of resonance of a mirror reflected.--Alex Sazonov (talk) 13:59, 31 August 2014 (UTC)

Reflecting 100%, as opposed to absorbing some of it as heat, for example? Just trying to understand what you're thinking. Nyttend (talk) 14:08, 31 August 2014 (UTC)

Yes. ScienceApe (talk) 18:09, 31 August 2014 (UTC)

I don't know if a perfect mirror is possible, but it doesn't violate the second law of thermodynamics. The second law says that no process can globally decrease entropy. All that a perfect mirror would do is to locally keep entropy constant. Looie496 (talk) 15:56, 31 August 2014 (UTC)

Well if it's not possible, it has to violate some law of physics right? If it violates no laws of physics, it should be possible. ScienceApe (talk) 18:09, 31 August 2014 (UTC)

If the mirror is not attached to something but is drifting in space, won't the photons that are hitting it "push" it a bit, causing it to accelerate? If the mirror is being accelerated, I think some of the energy of the original light beam must be being used to push the mirror. CBHA (talk) 18:37, 31 August 2014 (UTC)

Which to me would mean that the mirror is not reflecting as light all the light energy hitting it. Therefore ,a less than perfect mirror. CBHA (talk) 23:36, 31 August 2014 (UTC)

Reversible process might be a useful comparison. A thermodynamically reversible process isn't theoretically impossible (indeed, most thermodynamic calculations depend on them being available), but isn't achievable with real materials in finite amounts of time. A perfect mirror isn't theoretically impossible, but would require a material that didn't absorb electromagnetic radiation at any frequency (from radio to the most energetic gamma rays) - such a material doesn't exist in the real world, although there's no theoretical reason why it can't. Tevildo (talk) 18:48, 31 August 2014 (UTC)

Not a traditional "mirror", but according to total internal reflection, an interface can reflect all the light directed at it if the angle of incidence is right.--Wikimedes (talk) 19:00, 31 August 2014 (UTC)

Over the range of frequencies in which its refractive index doesn't have a complex component, yes. No materials possess that property over the entire spectrum. Tevildo (talk)

• Related Perfect mirror debuts (2013), related Perfect mirror. --prokaryotes (talk) 22:25, 31 August 2014 (UTC)

Yeah - but it only works at one very specific frequency - so it certainly doesn't achieve what our OP is asking for. SteveBaker (talk) 05:43, 1 September 2014 (UTC)

I would expect that straight conservation of momentum issues would preclude the construction of a perfect mirror. (Where a 'perfect mirror' is defined broadly as some construct or device that receives photons from one direction and returns the same number of photons of identical energy/wavelength travelling in a different direction, possibly along a reciprocal course. In other words, a photon comes in, 'bounces', and comes back with the same energy.) CBHA gets close to it with his 'mirror in space' thought experiment, but doesn't go quite far enough.

Consider a photon with momentum travelling to the right (call this a positive direction) with momentum p. We want a device that accepts that photon and delivers us a photon with momentum -p, that is, a photon with the same-sized momentum (and therefore the same energy and wavelength) travelling to the left. But wait—if the photon has a change in momentum of -2p, the mirror (and the planet it is attached to) has to experience a change of momentum of +2p. For any macroscopic object and reasonable photon momentum, 2p isn't much—but it also isn't zero. And you can't impart that impulse on the mirror for free—there's an energy cost. That energy comes from the photon itself. It is redshifted ever-so-slightly, so that the departing photon has a momentum of -(p-ε) and the mirror has momentum p-ε. While this is a one-dimensional model, the same reasoning applies in three dimensions. You can't change the direction of a photon without paying, somehow, for the change in momentum. TenOfAllTrades(talk) 21:48, 1 September 2014 (UTC)

I agree. Although, our OP doesn't preclude the mirror consuming energy in it's own right. So we could attach a very tiny rocket motor to the back of our 'perfect' mirror to eject material from the back of the mirror to carry away the momentum of the light bouncing off of it. (You could use a carefully controlled laser that would provide the same amount of light output). That suggests that a perfect mirror is possible, but you have to supply energy to it to keep it operational. However, I think even that is problematic. The problem is to detect the amount of momentum in the incoming light in order to generate the commands to the laser to apply the correct amount of counter-acting momentum...but since the commands to do that can only travel at the speed of light, the laser will always be a little bit too late...so the mirror would vibrate as momentum from changes in the amount of incoming light are counteracted by the laser...and that would manfiest itself as changes in the reflected light. To counteract THAT effect, you'd have to capture the incoming light, analyse it's nature and regenerate it perfectly at the output. I'm pretty sure the uncertainty principle would make that impossible. So, on balance, I still believe it's impossible. SteveBaker (talk) 14:43, 3 September 2014 (UTC)

Sirs, all the phenomena of thermodynamics always had consist only in the dynamics of the heat, is no longer what!--Alex Sazonov (talk) 04:40, 1 September 2014 (UTC)

Nothing that exists in the universe can defy the laws of physics. If something appears to defy the laws of physics, that can only mean that we have not yet figured out all the laws of physics. ←Baseball Bugs ^{What's up, Doc?} carrots→ 21:50, 1 September 2014 (UTC)

Toxicity of Hemlock and Nightshade

Hello, I am doing some research for a book and have the following two questions: Firstly, how poisionous are Deadly Nighshade petals/the purple flower itself? I noticed the wiki article only comments on the seeds/leaves/berries etc.

Secondly, can Deadly Nightshade and Hemlock (conium) both be touched with ones bare hands without poisoning occuring?

Thanks im advcance for your help! — Preceding unsigned comment added by 217.250.86.85 (talk) 16:08, 31 August 2014 (UTC)

I would expect that if just touching them was fatal, we'd all be very concerned about them, have public education and eradication campaigns, etc. Since the average person doesn't go around eating strange plants, they would be far less of a threat, if they must be ingested to poison us.

Incidentally, I understand that tobacco plants can cause contact poisoning, but only in certain circumstances. After a dew or rain, nicotine is drawn into the droplets, and pickers can absorb too much of that through their skin, and suffer from Green Tobacco Sickness. Still, it would take hours of picking, so it's not a threat to somebody just walking through them.

And of course there's poison ivy, poison sumac, and poison oak but those normally cause skin rashes only. StuRat (talk) 19:09, 31 August 2014 (UTC)

THE POISON GARDEN Website says of Deadly Nightshade; "There is disagreement over what constitutes a fatal amount with cases cited of a small child eating half a berry and dying alongside a nine year old Danish boy who, in the 1990s, ate between twenty and twenty five berries and survived." The same site has a page on Conium maculatum, poison hemlock which cites several people who died after mistaking it for carrot leaves or parsley. It doesn't say how much they ate. Alansplodge (talk) 20:35, 1 September 2014 (UTC)

But... but... they're natural! Monsanto has nothing to do with them! They must be good for you! Tevildo (talk) 21:43, 1 September 2014 (UTC)

mass of an electron at +1,000,000 V

An electron normally has a mass of 0.511 MeV. Suppose a perforated spherical electrode is somehow brought to a potential of +1,000,000 V. A loose electron from outside will therefore emit 1 MeV of energy, or gain 1MeV of kinetic energy, falling into the space.

Does a stationary electron inside the electrode therefore have a net negative mass?

If you can somehow neutralize (I mean, accurately account for) the charge effects, can it be observed to fall upward under the influence of Earth's gravity? Wnt (talk) 16:22, 31 August 2014 (UTC)

The (relativistic) mass of the accelerated electron will be 1.511 MeV, not 1.0 MeV. See cyclotron for the detailed mathematics. Tevildo (talk) 16:56, 31 August 2014 (UTC)

This seems to be a misapplication of the principle that in a conservative field, the state of an object is independent of it's path (or previous history). To use this principle to find out what a stationary electron does, you would have to decelerate the electron to 0 velocity and include the effects of the deceleration in your calculation.--Wikimedes (talk) 18:48, 31 August 2014 (UTC)

One of the great things about the theory of relativity is that it's relative. That means that the value of the relativistic mass, which (in some formulations) includes potential energy, depends on who is measuring it, and where they are. So, depending on where you pick your electrical ground (your point of zero potential energy), your electron will have a different amount of potential energy. Subsequently, if you calculate its relativistic mass and account for that potential energy, you'll get a value that depends on where your ground is located. This shouldn't be a surprise at all: if you were accounting for the relativistic mass by including kinetic energy, then the value you compute would depend on your inertial reference frame. In other words, this is not the first time you've encountered a "mass" whose value depends on how and where you measure it!

In classical electromagnetic theory, the electrical potential energy can be formulated as a gauge. Moving your "ground" is a simple change of scalar gauge. In fact, if you pursue formal study of relativistic electrodynamics, solving these equations will be among your first homework assignments, to make sure that you are comfortable using analytical mathematics to move beyond the conceptual weirdness.

Nimur (talk) 22:50, 31 August 2014 (UTC)

Hmmm, so far I don't see this. But let's nail down something first: at "neutral voltage", an electron and a positron have equal mass. Does this remain true no matter what you adjust the voltage to be? And if so, why doesn't that potential energy, that could be tapped at any time, have mass? Wnt (talk) 05:28, 1 September 2014 (UTC)

Remember that voltage is relative as well - we can only talk about the voltage _between_ two points, not the voltage _at_ a point or the "overall voltage" of a system. When you say "neutral voltage", where are you measuring it? Tevildo (talk) 07:14, 1 September 2014 (UTC)

Always believed that the mass of elementary particles is always been the force of their electric charge or the force of dynamics of their electric charge, because the mass of the electron is always been pleasant to consider the variable mass, so the electron is been never the absolute gravity.--Alex Sazonov (talk) 09:30, 1 September 2014 (UTC)

No, gravity and charges sometimes electric can not pleasantify in that they are being what was always been their mass is absolute unless without question and when gravities and more massives do sometimes make differently from that. So yes. Sebastian Garth (talk) 10:31, 1 September 2014 (UTC)

The question is what, does the elementary particles had a mass or they always had only the gravity of the electric charge?--Alex Sazonov (talk) 09:41, 2 September 2014 (UTC)

Absolute mass of all elementary particles is always be considered to be the mass of light, because is always pleasant to believe that the speed of light is always be the absolute standard of speed in physics, because it have not a limits, I think it's be wrong, because an electromagnetic induction is always been more much powerful than the magnetic induction, because the speed of electric current is always be absolute, so that the mass of the electron can be adopted as the absolute standard, although the electron is been never the absolute gravity.--Alex Sazonov (talk) 11:10, 1 September 2014 (UTC)

What is been the natural nature of the electron that is what had always the electron magnetism or electromagnetism?--Alex Sazonov (talk) 12:08, 1 September 2014 (UTC)

Do you think that science could researching the elementary particles which mass always is been immaterial, and does these elementary particles had a gravity?--Alex Sazonov (talk) 18:13, 1 September 2014 (UTC)

I believe that science does not makes sense to researching the elementary particles which are never observed in materials (substances), although they may had a gravity.--Alex Sazonov (talk) 07:56, 2 September 2014 (UTC)

If would be in nature been an absolute resistance which been determines the force of the charge and its voltage, the electric current would had never been in nature, is it truth?--Alex Sazonov (talk) 13:33, 3 September 2014 (UTC)

note: I've started a separate question on absolute voltage two below because this is way too fundamental of a point for any of us to be confused about without humiliation! And our article discussion seems confused... Wnt (talk) 13:21, 1 September 2014 (UTC)

September 1

Greenhouse carbon dioxide level

According to the article Carbon Dioxide, "Plants can grow up to 50 percent faster in concentrations of 1,000 ppm CO2 when compared with ambient conditions, though this assumes no change in climate and no limitation on other nutrients."

And from the same article, "Carbon dioxide content in fresh air ... varies between 0.036% (360 ppm) and 0.039% (390 ppm), depending on the location." And in the Toxicity section: "In concentrations up to 1% (10,000 ppm), it will make some people feel drowsy".

With this as background, is it practical and worthwhile to raise the CO2 level by lighting a small woodstove in a greenhouse? (Other things being equal. I.E., assuming that the level is not raised so high as to be toxic to the greenhouse workers, that the carbon monoxide level is not raised, and that the greenhouse is not overheated.) Thanks, C7nel (talk) 01:36, 1 September 2014 (UTC)

Sounds dangerous. Using a stove in an unventilated area can produce deadly carbon monoxide and other combustion products. If you really wanted to raise CO₂ levels, I'd suggest buying a tank of it. You could still get too much carbon dioxide in the air, but at least that would eliminate the other dangers. Small tanks would be safer, since even if it all leaked out at once, it wouldn't be that much. StuRat (talk) 01:57, 1 September 2014 (UTC)

From my experiments the limiting factor in plant growth is light. Not CO2, water or other nutrients. Obviously if those are lacking the plant will grow slower, but once those needs are met the limit is light. I have not tried using a solar concentrator to see if that helps. Ariel. (talk) 02:13, 1 September 2014 (UTC)

I doubt it is just light or just CO2, and this paper at least agrees that ~99% of various plants grew more when exposed to more CO2 alone Fig 1 http://www.science.poorter.eu/1993_poorter_vegetatio.pdf . One obvious mechanism is that if there is more CO2 then the stomata don't need as much air circulation so the plant loses less water via its leaves, which is one of the other limitations on plant growth. Greglocock (talk) 02:08, 2 September 2014 (UTC)

Yea, marijuana grow houses seem to install major grow lights to make it grow faster. I am guessing that the cost is prohibitive for less valuable crops. StuRat (talk) 02:30, 1 September 2014 (UTC)

No, I'm not growing marijuana :) Just regular plants in a window box. Ariel. (talk) 07:24, 1 September 2014 (UTC)

In Victorian times, some rich people in England maintained "pine houses" – heated greenhouses in which they raised pineapples to serve at table. Some heated their pine houses with a coal boiler (in an nearby outhouse) and hot-water pipes, others used heaps of vegetable matter (grass cuttings, potato peelings, etc.) decaying under the benches of the pine house. The latter was found more effective in promoting growth of the pineapple plants, and people wrote of the benefits of "live heat" relative to "dead heat". Later they realised that heat is just heat, but the decaying heaps were promoting pineapple growth by increasing the CO₂ level in the pine houses. Maproom (talk) 06:54, 1 September 2014 (UTC)

Pineapple is special in that it uses the efficient CAM photosynthesis - perhaps it can use the extra CO2, if so than corn and sugar cane should also be able to since they use C4 carbon fixation. Ariel. (talk) 07:24, 1 September 2014 (UTC)

Is there such a thing as absolute voltage (and thus true electrical neutral)?

This is based on the next-to-last question above, but deserves its own heading: someone said that voltage somehow is only relative as a result of it being a gauge theory. But my impression was that a device such as an electroscope truly measures, if only approximately, a zero voltage when the little gold leaves hang down next to each other. (sorry, on second thought that part was dumb) Talk:Voltage is full of debate like this, with some saying that neutral voltage can be defined as the voltage "at infinity". Given the extreme electrical charges in space I have a hard time picturing that as practical, but is it theoretically valid? Last but not least there was my supposition above that the masses of electrons and positrons (or associated with their presence in some way) ought to vary depending on where they are in an electric field -- it seems like Stackexchange leans toward the idea that a charged battery contains more mass than a discharged battery, and reddit the same of capacitors. So I'm thinking a third way to define zero voltage is where positrons and electrons have precisely the same mass. Note: even if they're valid, I don't know all three methods agree. So let's try to settle this, and hopefully find reliable sources to update Voltage to dispel the world's confusion: is there an absolute zero voltage, and do we know what it is relative to the range encountered on the ground and in the air of our planet? Wnt (talk) 13:19, 1 September 2014 (UTC)

This is a very common cause of confusion. I tried to explain the answer as clearly as I could in the "Voltage" section of the membrane potential article, and I don't think I can do any better than refer to that. But let me quote from the third paragraph there: In mathematical terms, the definition of voltage begins with the concept of an electric field E, a vector field assigning a magnitude and direction to each point in space. In many situations, the electric field is a conservative field, which means that it can be expressed as the gradient of a scalar function V, that is, E = –∇V. This scalar field V is referred to as the voltage distribution. Note that the definition allows for an arbitrary constant of integration—this is why absolute values of voltage are not meaningful. Looie496 (talk) 15:17, 1 September 2014 (UTC)

Perhaps it is time to review constant of integration.

With due respect, Wnt, the best way I can answer your question without writing any equations is this explanation. Please understand that this is my best and sincere effort to represent your question conceptually (and not in any way an attempt to be condescending, although if you can understand this explanation, you might get a good laugh). You ask whether there is absolute voltage. This is logically equivalent to the nonce question, "what is the length of a piece of string?" Then you refine this concept by expressing confidence that we can find a "true" electrical neutral. This is logically equivalent to saying, "what if we tied one end of the string down at the position 'zero'?"

Does this help? Voltage is the path integral of the electric field. It is computed by adding up a quantity along a path integral - sort of like how we measure the length of string. There are many clever methods to compute this value, but it always depends on where the two ends of the string are. We can measure the length of any specific string, but we cannot answer the question in general - at least, not by providing a numerical value. When we define the two points - i.e. we measure voltage between two points - it has a definite value, because it is a definite integral. When we do not define the endpoints, we have an indefinite integral, to which we may add a constant of integration. Nimur (talk) 16:11, 1 September 2014 (UTC)

Staying with the "piece of string" analogy, it might be useful to consider gravitational potential energy. The gravitational potential energy of a mass m in a uniform gravitational field is mgh. This quantity is meaningless unless we know what h is; until we define the point we're measuring the height from. On the electroscope issue, no deflection of the leaf means there's no voltage between the leaf and the case of the electroscope, so there's a definite but arbitary reference potential. Tevildo (talk) 16:47, 1 September 2014 (UTC)

On consideration I suppose I was making a basic error thinking about the electroscope -- even though the leaves obviously move apart, this isn't due to their voltage but due to their charge; i.e. it is conceivable they could be inside a very large spherical metal electrode, wired directly to it, but because the charge repels itself to the outside of the electrode, the charge goes away and the leaves fall together.

Nonetheless, the mgh analogy seems like a bad one. Relative to one source, matter really does have a zero potential at infinity, and it really does emit energy to reflect the loss of relativistic-ish mass as it falls in; in the case of a black hole, as I understand it, even most of the rest mass consumed can end up being radiated as energy. And there's a specific phenomenon, the event horizon, that forms a neat ruler line marking the precise absolute bottom of the gravity well. The energy of a gravitational potential is -G mM/r, the Schwarzschild radius is r = 2 GM/c^2, so the potential there is - c^2 m /2 ... I forget why there's a /2 here, but I remember seeing claims that actually the amount of energy was equal, so there might be a relativistic correction I've missed. The point is though, it's an absolute potential as evidenced by these clear ruler markings at the top and the bottom of it. No? Wnt (talk) 17:09, 1 September 2014 (UTC)

You're conflating "really convenient reference point" with "absolute reference point." Nimur (talk) 17:17, 1 September 2014 (UTC)

Also I should mention the photon sphere at 3 GM/c^2, i.e. where the absolute gravitational potential is precisely -1/3 of the mass of any given particle. (Hmmm, wonder if there's anything at 4...) Wnt (talk) 17:22, 1 September 2014 (UTC)

Wnt, you are trying to explore some very complicated equations, while you are demonstrating to us that you are uncomfortable with elementary mathematics. For your own sake, put the advanced topics in mathematical physics to the side, for a little while, and review the elementary concepts of analytical mathematics, because you cannot meaningfully understand mathematical physics if your comprehension of calculus is broken. Would you like a recommendation on some good books to help you refresh those concepts? Or, if you've never learned them, would you like some recommendations for introductory texts?

Nimur (talk) 17:25, 1 September 2014 (UTC)

I understand the calculus of doing an integral; what I don't understand is why the two of you use that as proof of something. Sure, position is the integral of velocity ... so there's no such thing as absolute position ... so you can put the equator wherever you want it, it doesn't mean anything. It is too easy to let the math obscure a point. Just because you can calculate some quantity doesn't mean you've explained the full system.

P.S. apparently there's yet another "ruler marking" in the gravity potential at 9/4 G M / c^2, where the redshift reaches two, that controls the possible compactness of stars. [4] (I haven't yet even looked at this) Wnt (talk) 17:30, 1 September 2014 (UTC)

But that's exactly the point. Voltage is the antiderivative of the electrical field in exactly the same way that position is the antiderivative of velocity. Incidentally, I think your explanation of the electroscope is a bit off the mark, perhaps the article is not very well written. The electroscope is actually an instrument for detecting an electrical field. It does not directly detect voltage. A zero reading for an electroscope tells you that the voltage is locally constant, not that it is zero. Looie496 (talk) 17:41, 1 September 2014 (UTC)

Wnt, we aren't presenting "proof." We are presenting definition of terms. If you aren't familiar with this distinction, you are again demonstrating that you are unprepared for analytical exercises in advanced mathematical physics. (Contrast: voltage is defined; while its path independence is proved, subject to specific definitions). This proof would be a good one for you to study, and ask questions about it if you get stuck!

We want to help you understand these things. I volunteer my time here because I like helping people understand things! But we have to be pragmatic: I can see that you are presently on completely the wrong side of a massive conceptual gulf, and the way to bridge this gap is by reviewing mathematical concepts. Every hour you spend trying to apply your present methods to understand black holes is taking you deeper into the ravine of self-induced confusion. Nimur (talk) 17:36, 1 September 2014 (UTC)

I may indeed be on the wrong track, but I don't think it is philosophically wrong to try to understand a confusing point by asking thought-experiments. For example... suppose you have a plasma of electrons and positrons in a chamber, all with the same rest mass, and now you apply a strong electric field to it. Most of the electrons go to + and most of the positrons go to - of course, but the electrons that were furthest from the + pick up the most speed (more relativistic mass) reflecting their higher electrical potential when they were near the - electrode. But now suppose you have some positronium "atoms" amid the mix; being neutral, they are little affected. Now my thinking here was that the potential energy of the electrons being closer to the negative electrode is equivalent to some amount of mass, which might be measured. But ... I'm not sure a measurement actually would back this up. When I picture those positronium atoms spinning and going into and out of excited modes, I suppose the electron wouldn't start to remain at the center in one of these because it has "increased mass" from being near the negative electrode, while the positron takes the same role in those at the other end. The mass is real, we have an article on electric potential energy that explains how to calculate it, but understanding just where it is and what it affects isn't as obvious. Wnt (talk) 18:10, 1 September 2014 (UTC)

Should be interested in the speed and speed accelerations in natural magnetism as physical-chemical phenomena which had creating an inert masses, and in particular should be interesting in the electromagnetic induction.--Alex Sazonov (talk) 03:32, 2 September 2014 (UTC)

---

Potential energy gravitates, which means that we can in principle measure the absolute quantity of it, and even its spatial distribution, by measuring spacetime curvature.

Potential energy is the energy of the field, and there's only one field in total, not one per charged particle. Thus it doesn't make sense to talk about "the potential energy of a particle". A charged battery or capacitor does have more mass than a discharged one, but that mass doesn't belong to any of the particles. In a capacitor, it's mostly located in the dielectric.

Voltage is only well defined when the total potential energy can be written in the form (U₀ +) q·f(x) where q and x are the charge and position of some object. Within its domain of applicability, only voltage differences matter. There's probably nothing deeper to say about voltage because at a deeper level it no longer makes sense as a concept. -- BenRG (talk) 21:56, 1 September 2014 (UTC)

@BenRG: This was a very good answer, and similar to what I found at [5]. It would be interesting to further explore when and how "voltage no longer makes sense as a concept". And our article on electric field says that the energy density of the field is 'proportional to the square of the amplitude', which perplexes me first, well, because they link amplitude referring to sinusoidal waves, but here we're speaking of a static field (I assume that's a mistake?), and mostly because if I take two protons and jam them side by side, the amplitude of the field should be double the two individual fields, so the energy should only be 4x, but classically I could sink an infinite amount of energy into that push, and even IRL a ridiculously large amount. Stackexchange gives me a formula but alas not the definitions or explanation: $\int |\nabla \phi |^{2}dV=-\int \phi \nabla ^{2}\phi =\int \phi \rho$ and says that the self-potential of a point charge is divergent (which I suppose would explain why the 4x is a big deal?) but I'm still not quite seeing it. I ought to look further here, but I might as well poke head up and see if someone tells me I'm on the wrong track. Wnt (talk) 14:39, 2 September 2014 (UTC)

Saying that "voltage" doesn't make sense in general is like saying that "up" doesn't make sense in outer space. It's more a matter of word definition than physics.

$\int |\nabla \phi |^{2}dV=-\int \phi \nabla ^{2}\phi$ is Integration by parts#Higher dimensions together with the assumption that φ vanishes on the boundary of the region of integration (which is probably at infinity). $-\int \phi \nabla ^{2}\phi =\int \phi \rho$ uses Poisson's equation in weird units (normally there would be a factor of 4π or 1/ε₀ in front of ρ—I suspect they just forgot it).

"Amplitude" in the article means vector norm/magnitude. I changed it.

Superimposed point charges should have twice the energy of the same charges separated to infinity because (E+E)²/(E²+E²) = 2. But E = +∞, so "twice" is infinitely more. The usual way of dealing with the infinities is to impose some sort of cutoff in the integral, justified because Maxwell's equations must break down at short distances. See regularization (physics). In this case, there's a trick you can use: write

${\frac {1}{2}}\int |E_{1}(\mathbf {x} )+E_{2}(\mathbf {x} )|^{2}={\frac {1}{2}}\int |E_{1}(\mathbf {x} )|^{2}+\int E_{1}(\mathbf {x} )\cdot E_{2}(\mathbf {x} )+{\frac {1}{2}}\int |E_{2}(\mathbf {x} )|^{2}$

and then just discard the first and third terms because they're independent of the separation of the particles. The middle term should integrate to $q^{2}/|\mathbf {x} _{1}-\mathbf {x} _{2}|$. -- BenRG (talk) 17:30, 2 September 2014 (UTC)

This makes sense. If it takes an infinite amount of energy to push two point charges together, then it must take an infinite amount of energy to push one point charge together. But the point charge presumably can be replaced by a radially symmetric distribution, approximatable as a sphere of charge with no electrical force (so no field) inside by the shell theorem, and acting like a point charge outside. Which leaves me to integrate for r from x to infinity, where x is some small value. The volume is 4 pi r^2 * dr ; the magnitude squared = ( e / 4 pi eps0 r^2 )^2 ... I think. So that's the integral of e^2 dr / (4 pi eps0^2 r^2), I think. Which gets me -e^2 / (4 pi eps0^2 r) for r=(some small value) - (r at infinity), i.e. only the small value counts.

Now to check sanity by units... eps0 (I mean, vacuum permittivity) is ε0 = 8.854 187 817... x 10−12 [F/m] where 1 F = 1 s4·A2·m−2·kg−1 so that's 8.854 187 817... x 10−12 s4·A2·m−3·kg−1. The charge on the electron e is −1.602176565(35)×10−19 C where 1 C = 1 A s. So (might as well multiply the values too) I'm getting, oh, 3.204 x 10-38 A^2 s^2 / 9.8509 x 10-22 s4·A2·m−3·kg−1 = 3.253 x 10-17 m^3 kg /s^2 / r. And a joule, incredibly, is actually m^2 kg /s^2, which means I couldn't possibly have fouled up this calculation. 🙈 🙉 🙊 :) (no, really do speak evil of it when you find the bug)

As a sanity check, the energy actually in the field around an electron can't really be more than the mass of the electron itself, because wherever the electron goes it goes... right? The mass-energy of an electron is 9.10938291(40)×10−31 kg * ( 299792458 m/s) ^2 = 8.187 x 10-14 m^2 kg / s^2, which means that r can't be less than, oh, a millimeter. Arrrgh. I oughtn't post what's probably just a really stupid math error, but might as well check in and see if it turns out that there's something I ought to know about this calculation. Wnt (talk) 21:30, 2 September 2014 (UTC)

Inside your car there is a zero voltage point at the negative terminal of the battery; inside your house there is a zero voltage point where mains wiring is grounded (often to a water supply pipe). A zero voltage point for the whole universe is hard to find, hence the OP's question. The Bohr model of the atom describes it as a tiny orbital system of charged particles and the potentials of the particles are calculated in terms of the work needed to bring a test charge "from infinity". A more realistic wording is "from a point so distant that the field strengths of the atom's particles are negligible, and the atom being modelled is alone". The Bohr model, and the better refined Atomic orbital model, do not require an absolute zero voltage to exist anywhere; they are isolated atom models that work the same way whether the atom of, say copper, is deep in the ground or in a high-voltage cable. The article Introduction to gauge theory explains here how our understanding of electricity and magnetism by Maxwell's equations having gauge symmetry is consistent with every practical voltmeter needing two probes. A single-probe voltmeter that could indicate absolute volts is as elusive as the Magnetic monopole. We would conclude that no absolute zero voltage exists but for the implication of mainstream Cosmology that speculates A) the singular source of the Big Bang had no potential gradient i.e. it was all at the same voltage which we may call the absolute voltage reference, and B) whatever the Ultimate fate of the universe there cannot remain any voltage difference (because that could drive an electric motor, meaning that the story isn't over) so we may also call that the absolute voltage reference. There is no mainstream cosmology that claims the voltages in A) and B) would be different, from which we conclude that there is an absolute zero voltage reference but it presently exists only as the theoretical average voltage that matter would attain if all insulators including vacuum became conductors. 84.209.89.214 (talk) 13:23, 2 September 2014 (UTC)

Actually that's not really convincing as an argument. Unless there is proton decay - and even electron decay - one expects the universe to retain differences in electrical potential. And the existence of a literal singularity before the Big Bang is something at least I don't believe in. Wnt (talk) 14:43, 2 September 2014 (UTC)

Wnt, I know this has been said already, but I have to say it again: by definition, voltage is the potential difference between two points. By definition. By analogy, distance is the position difference between two points. What's the absolute distance of New York? What's the absolute distance of your house? Do you understand why the question makes no sense? --Bowlhover (talk) 17:37, 2 September 2014 (UTC)

Come on, not the same thing at all. In certain models of the Universe it makes perfect sense to talk about the absolute potential at a point — it's the potential difference between that point and the "point at infinity". For example, if space is asymptotically flat, and electrically neutral on the average, then I'm pretty sure this is well-defined (I don't know GR well enough to be sure there are no gotchas hiding in there somewhere). The "absolute distance of your house" relative to the point at infinity would always be infinity, but this is not true for electrical potential. --Trovatore (talk) 20:01, 2 September 2014 (UTC)

Trovatore, you are also conflating a "really convenient reference-point" with an "absolute reference-point."

A large number of mathematical formulae can be dramatically simplified if their definite integral is written with one limit set to infinity. This is called an improper integral. You're a mathematically-inclined individual! You already know this. This choice for the limit of integration can make the computation easier, especially for many of the potential functions we find in real-world problems.

However, solving the improper integral doesn't change the definition of potential-difference: it just asks us to consider the conceptual idea that a potential difference converges when considered across large distances. Nothing about that observation changes anything. The choice to use "a point that is very far away" as the reference-point is still totally arbitrary. The fact that the integral does converge is an important detail: it means that the potential energy functions we normally encounter are non-pathological. They frequently have radial symmetry. And so on. These observations are important to the physics! But they don't make the definitions change.

Nimur (talk) 21:18, 2 September 2014 (UTC)

Well, OK, now this has become more of a philosophical argument than a scientific or mathematical one. If potentials are well-defined relative to the point at infinity, but that does not qualify as an "absolute reference point", then what, if anything, would qualify? In the hypothesized case (flat, electrically neutral universe), it's the same for all observers, or at least all observers in our universe, right? How much more "absolute" than that do you want to get? I think we're flirting with Scholasticism here. --Trovatore (talk) 21:25, 2 September 2014 (UTC)

You bring up an interesting point; but one that only holds for those non-pathological, well-behaved functions we talk about in basic physics, like the coulomb potential. If we want to build a mathematical framework that is useful for more general problems - both real and theoretical potential functions - we need to stick to our definitions very carefully. I'm not just defending the definition for the sake of being argumentative!

For example, the Yukawa potential generalizes the Coulomb potential. In the general form, its improper integral does not always converge. Or consider the magnetic vector potential, or any other field that may represent a non-conservative potential. As you can see, there are potentials - real and theoretical - for which two observers at infinity could disagree about magnitude!

If we were to stretch the definition of the word "absolute," or if we were to assume that "a point at infinite distance" is the universal reference point, then we would not be able to mathematically describe many real observations. We would not be able to mathematically explore theoretical potential fields that represented anisotropic or inhomogeneous interactions. We need to stick to the mathematical definitions so that we can consider real, testable hypotheses for a more general class of problems than simple electrostatics. We could, with equally valid abuse of notation, stretch the meaning of "absolute" to define an inertial reference frame for which the Lorentz factor is equal to unity. It's "absolute" with respect to a specific problem-setup! Obviously you see why this is not "absolute" at all, for an entire category of interesting physics problems!

You asked "what, if anything, would qualify as absolute?" ... Nothing. Nothing qualifies as absolute. This isn't simply a regurgitation of "physics establishment" dogma: it's a real thing that we have to be aware of when we frame our problems with mathematical models.

Nimur (talk) 21:57, 2 September 2014 (UTC)

Well, so if "nothing qualifies as absolute" , my question is, is this a contingent or a priori truth? That is, is there any possible world in which there would be absolutes? If not, can you explain what work the word "absolute" is doing, and why we don't simply redefine it to be more useful, by referring to some property that is possibly (even if not actually) instantiated? On the other hand, if it's a contingent truth, then can you explain in what counterfactual situation you would call something absolute? That would help me understand what you mean by the word. --Trovatore (talk) 23:46, 2 September 2014 (UTC)

Sure: there are a lot of abstract, non-physically-realizable absolutes. Most of them are pretty abstract. For example, the total ordering of the set of all integers is an absolute: two is absolutely larger than one; there is no "relative" scheme in which two is smaller than one or equal to one. This absolute relationship follows from our definitions of what integers are.

The cardinality of the reals is absolutely larger than the cardinality of the integers. There is no conceivable hypothetical universe in which this is untrue. This is an absolute relationship between two entities that directly follows from the definition of those entities.

I think it's no coincidence that I'm readily able to find mathematical abstractions that form absolute relationships, but that I'm unable to contrive good examples of any physical manifestations of absolute relationships.

Nimur (talk) 23:58, 2 September 2014 (UTC)

(ec) Sure, you can define the reference point to be infinity, and then call the resulting potential difference an "absolute voltage". I don't really care what term you call it. It remains true that 1) voltage is, by definition, a potential difference, 2) infinity is no better or worse than any other reference point, and 3) if I define voltage to be 10 volts plus whatever you think it is, no physical prediction about the world would change. --Bowlhover (talk) 22:01, 2 September 2014 (UTC)

Well, it's "better" than any other reference point in at least one way; namely, in the hypothesized situation, it can be defined independently of any artifact or of the observer. Yes, you can also say that about "take the potential difference to infinity, and then add 10V"; it's "better" than that one in the sense of being more naturally motivated. --Trovatore (talk) 23:46, 2 September 2014 (UTC)

To reset the philosophy here, my question wasn't meant to be merely "is voltage as the term is conventionally used provided with an absolute zero value", though that has been answered and it is interesting that it is only defined in relative terms. It's also not meant to be one of whether we can define a purely arbitrary zero, a ceremonial platinum-iridium Leyden jar that they can keep in that place in France where they have the standard kilogram. Rather what I really want to get at is whether there is a universal standard reproducible procedure whereby we can work out a zero voltage point that would be the same whoever referenced data by it. If such a thing exists, then voltage is not purely relative, at least in my opinion.

Now, for gravitational potential, I think it's pretty clear there is such a point. Given access to any black hole in the cosmos, you could measure the exact position of its event horizon, then measure the exact velocity of a probe dropped from your position as it approaches it. Given access to any neutron star you could use a probe to measure where the photon sphere is located, and measure the distance dropped to it. These things are impractical, not impossible. By contrast, I'm not sure if measuring gravity "at infinity" is possible because whichever way you look there are more stars. (N.B. I am assuming that the event horizon of a black hole in a cosmic void would be smaller than one at the center of a galaxy made from the same mass; if that's wrong please enlighten me!) For electrical potential, I still don't know any method other than "at infinity" exists, and we know how extreme the voltages in space can be even quite far from the sun. Wnt (talk) 22:06, 2 September 2014 (UTC)

Ah, black hole event horizons are a little more subtle than that—they're not fixed dotted lines in space. Different observers of a black hole will see the event horizon as being in different locations. (Fun fact: to an observer approaching a black hole, the event horizon will always be beneath him.) TenOfAllTrades(talk) 14:28, 3 September 2014 (UTC)

September 2

Light, momentum, and refraction

We had the "momentum of light" topic ago: When a beam of light hits a mirror, it transfers momentum, so at least a very light near-perfect mirror could be pushed around by bright light.

Now, what about refraction? Let's say a beam of light, coming in from the left, hits a prism and gets refracted:

     /\

=>==/  \

   /____\\

          \\

            \\

This time, the momentum doesn't change sign, but still changes direction: from horizontal to diagonal. Does the "missing momentum" end up in the prism? (I suspect it does; it has to go somewhere. With enough beam power, the prism could levitate - at least in theory.)

That momentum change would point up and slightly to the right. However, there are two refraction events: one, when entering the prism, and two, when leaving. Both times, the only thing to act on is the part of the surface through which the beam enters/exits. What exactly does the light act on? The glass molecules?

For a conducting medium, I'd guess the free electrons. However, the conductors I know (metals, graphite) are either opaque or reflective, not transparent. The transparent materials I know (glass, plastic) do not provide free electrons. Does the light act on the bound electrons instead?

Also, entering a prism, the light will get slowed down. Does the loss of speed translate into another momentum transfer, pushing the glass surface in (which would be the only momentum transfer if the light hits at right angles)?

     ___

    |   |

=>==| = |======

    |___|

Would this glass cube get pushed to the right by the momentum transfer alone (i.e. even if we assume that it doesn't reflect any light) ? - ¡Ouch! (^{hurt me} / _{more pain}) 06:40, 2 September 2014 (UTC)

It wouldn't push the cube; when exiting, the original momentum would be restored. One question solved. - ¡Ouch! (^{hurt me} / _{more pain}) 06:48, 2 September 2014 (UTC)

I thinking it would be noted that the resonance of the light is always been only when the light had a mirrory (зеркальность), so the absolute reflection and absolute refraction always had the mirrory (зеркальность).--Alex Sazonov (talk) 07:15, 2 September 2014 (UTC)

If in nature had an absolute optical environment, so that the light is been able to reach their absolute values!--Alex Sazonov (talk) 15:49, 2 September 2014 (UTC)

Note: The original thread was [6]. I'd been thinking I ought to finally set up a proper VPN before ... [this space intentionally left blank] ... but procrastinated. But I'd also welcome further discussion/explanation of what was said there. Wnt (talk) 14:53, 2 September 2014 (UTC)

Optical Refraction that causes the path of a light beam to bend where it crosses the interface between two media (e.g. air and glass) in which it has different velocities and therefore different wavelengths is more intuitively understood from the wave-view of light than the particle-view. Thus the analogy: "Imagine a marching band as they march at an oblique angle from pavement (a fast medium) into mud (a slower medium). The marchers on the side that runs into the mud first will slow down first. This causes the whole band to pivot slightly toward the normal (make a smaller angle from the normal)." The particle-view though arguably valid tends to lose sight of the finite width of every light ray, making refraction harder to explain. However it is useful when considering the momentum of light as the OP is doing. The prism gains Angular momentum in the direction opposite to the bending of the beam that passes through it. The mechanical action and reaction occur in the electron clouds of the surface molecules of the prism. This would also be the case in a prism made of a solid transparent conductor such as Indium tin oxide. 84.209.89.214 (talk) 15:27, 2 September 2014 (UTC)

The light do transfer momentum to the prism when it is refracted. The photons are mainly interacting with the electrons, but since they are bound the momentum is transfered to the atoms and to the prism. This phenomenon is the working principle of optical tweezers, so you will find a more thorough explanation in that article. Ulflund (talk) 16:20, 2 September 2014 (UTC)

For light entering a different refractive index, it is going to have some reflection back off the surfaces. For your perpendicular case the light will be reflected directly back, and this will increase the momentum transferred to the glass block. Graeme Bartlett (talk) 20:41, 2 September 2014 (UTC)

I have a question, does the light can do reflecting and refracting himself by himself?--Alex Sazonov (talk) 16:14, 2 September 2014 (UTC)

Photons do not interact directly with other photons, but in a non-linear optical medium they can indirectly do so. In high power lasers the phenomenon of self-focusing, where the high intensity changes the refractive index differently in different positions, thus resulting in refraction. Finally two-photon physics is the field studying interactions between photons and photons in vacuum, although this only occur through higher order where one photon first turns into a fermion anti-fermion pair. Ulflund (talk) 16:31, 2 September 2014 (UTC)

The double-slit experiment start reading here is fundamental to understanding how light can interfere with itself. 84.209.89.214 (talk) 03:47, 3 September 2014 (UTC)

Sense of the nature of physical-chemical phenomena

Could the nature of a physical-chemical phenomenon to refute anther nature physical-chemical phenomenon?--Alex Sazonov (talk) 11:10, 2 September 2014 (UTC)

The verb to refute means to contradict in words someone's argument, which I thinkfirst thought is not what you are asking about. I understand understood your question as "Could one physical-chemical system in equilibrium disturb another system in equilibrium?" The first issue to answer is whether there is a way to expose the systems to each other without disrupting the equilibrium of either. For example, the Mechanical equilibrium of two children on a Seesaw and the Dynamic equilibrium of a certain reversible chemical reaction in seawater are necessarily independent equilibriums that cannot be tested against one another. Generally speaking, if A and B are elements in equilibrium and they are exposed to another pair C and D of elements in equilibrium, then a reaction in any of these pairs may disrupt both equilibriums: AC, AD, BC or BD. (For "elements" substitute whatever force, concentration, rate, etc. is in equilibrium.) There is also a special case in chemistry of Catalysis where the rate of a chemical reaction, which could be a constituent of some greater equilibrium, is abruptly increased when the substance called the catalyst (itself in self-equilibrium) is introduced. 84.209.89.214 (talk) 14:43, 2 September 2014 (UTC) I apologise for misunderstanding your question!

I believe that, the paragraphs (sections) of physics and paragraphs (sections) of chemistry could never deny each other, both in their unison and as among themselves, because the physics and chemistry always had the mutual of universal knowledge.--Alex Sazonov (talk) 15:27, 2 September 2014 (UTC)

Physics and chemistry are studies that overlap, as demonstrated in the articles Physical chemistry and Chemical physics. 84.209.89.214 (talk) 20:58, 2 September 2014 (UTC)

What is been Alex Sazanov's Native Language?

The name seems like some sort of mock Slavonic, but the "user's" grammar corresponds in no way to any Slavic language. Is been this some sort of joke? μηδείς (talk) 19:54, 2 September 2014 (UTC)

I thought at first that the questions were trolling, then that they were being translated from Russian, but I assumed good faith. It would be interesting to know. Dbfirs 21:37, 2 September 2014 (UTC)

I wonder if it is an Eliza program with the bad grammar to cover up any problems. Dmcq (talk) 22:19, 2 September 2014 (UTC)

язык Стол-ичная ВСЕГДА лучше будет возможно назад в будущее рассмотреть?--Digrpat (talk) 22:25, 2 September 2014 (UTC)

Assuming good faith even if only, as Douglas Adams might have said, for the sheer mental exercise of it, it strikes me as not completely impossible that Sazonov might have learned just enough English to be dangerous at some point, extrapolated who-knows-what to invent his own grammatical rules, and these are now fixed ideas that are somewhat refractory to evidence or observation. I do find that his contributions have gotten somewhat less impossible to understand that they were at one time, although whether this is a function of an actual change or merely my exposure to them is difficult to be sure. --Trovatore (talk) 23:12, 2 September 2014 (UTC)

(For what it's worth, this user is blocked on ruwiki. His contributions there appear to be in perfect Russian, but make absolutely no sense: he's spouting scientific gibberish.) -- 79.233.115.170 (talk) 03:57, 3 September 2014 (UTC)

This seems the logical place to apologize for saying he's "being rubbing off on me" in a recent edit summary. What I meant to say, of course, was he "is been rubbing off". I meant to make a dummy edit to this effect, but couldn't think of the right minor change. InedibleHulk (talk) 06:49, September 3, 2014 (UTC)

Why do I get a feeling we're being subjected to a Turing test. The bad grammar, rubbish "science" and a consistent failure to actually respond to any question or comment directly addressed to him/it, seems to me to add up to some kind of AI test. Roger (Dodger67) (talk) 11:55, 3 September 2014 (UTC)

What would be the opposite of artificial intelligence? Edison (talk) 13:17, 3 September 2014 (UTC)

Which of these Two Kidney Situations Is Better?

Out of curiosity--serious question: Is it better for someone (who, for whatever reason, previously lost one kidney) to only have one kidney of his/her own (with his/her own DNA) or to have one kidney of his/her own and one kidney which was donated to him/her from someone else (with someone else's DNA)? Futurist110 (talk) 20:57, 2 September 2014 (UTC)

Organ transplantation is major surgery, with all the associated risks. The transplant recipient will likely need to remain on antirejection meds for the rest of his life, with the associated risks and side effects. In contrast, individuals with just one fully-functional kidney are generally just fine. Heck, in unilateral renal agenesis, individuals get by with just one kidney for their entire lives, typically without major medical consequences.

So really, one is asking whether the very tiny risk that an infection, malignancy, or injury could damage a lone kidney is greater than the risks associated with major surgery and long-term immunosuppressant use—and the answer is almost certainly not. (And in many circumstances, there is still the possibility of arranging a transplant after the first kidney starts to go south.) The other issue which arises as well is that donor kidneys are a finite and limited resource; no ethical transplant physician or surgeon is going to 'waste' a donor kidney on someone who doesn't need one. TenOfAllTrades(talk) 21:51, 2 September 2014 (UTC)

And no ethical funeral director would call death the "better option", but it does pay the bills. Of course, you specified better for the person with the kidney, but you didn't specify whether it's better to give or receive. If giving's better, take a kidney. If receiving is, let it be. InedibleHulk (talk) 06:45, September 3, 2014 (UTC)

I can't actually tell what you're trying to ask, and the OP's question seems perfectly clear.... TenOfAllTrades(talk) 13:48, 3 September 2014 (UTC)

September 3

The light of the sun

Does the light of the sun had so great inductive magnetism that if our planet had been not a natural magnetism, our planet would been enveloped by fire?--Alex Sazonov (talk) 05:59, 3 September 2014 (UTC)

The magnet helps, in this case. We must give the stratosphere credit, too. But not Stratos, in this case. Also helps that we're simply far enough away. All the forces of good on the planet didn't do much for Mercury. InedibleHulk (talk) 06:35, September 3, 2014 (UTC)

Thanks much! Does the natural magnetism of our planet had slowing the inertia light of the sun?--Alex Sazonov (talk) 08:49, 3 September 2014 (UTC)

The earth's magnetic field has almost no effect on sunlight. But it does affect the solar wind. At the energies involved here, light behaves in a linear way, so that light can pass through other light, or electric fields or magnetic fields without any interaction. Graeme Bartlett (talk) 13:24, 3 September 2014 (UTC)

I thinking when the cosmic objects are incoming in the space of the natural magnetism of the planet Earth, always is been created the exit of enormous dynamic energy of the magnetic induction, which been causes burning and glowing and so a force of molecular friction to this is been only ratio of private case.--Alex Sazonov (talk) 15:48, 3 September 2014 (UTC)

Ikat Weaving in China

In ikat:

Ikat is most characteristic of Indonesia, though ikats have also been woven in India and central Asia. Double ikats are produced in a few places including the Okinawa islands of Japan

I find it amusing that ikat is known to be practiced from India, central Asia to Japan.

China is surrounded by these countries.

Yet, the article does not seem to mention China.

Do Chinese people use ikat to make their clothing? -- Toytoy (talk) 08:15, 3 September 2014 (UTC)

Note: Factory textile technology always been defines all sets (kinds) in textiles, because a factory textile technology is always been forms the start of the new features in textiles, that is a factory textile technology is always been completely defines the development of textiles.--Alex Sazonov (talk) 12:54, 3 September 2014 (UTC)

Car scraping floor at foot of ramp

I often park in a multi-storey car park. It has ramps between floors that are at a fairly shallow angle, connecting two flat surfaces (ie its not a continual ramp). I've noticed that if I drive down a ramp just a bit too fast, something underneath my car will scrape the floor around the time when I hit the flat surface, whereas if I drive just a little slower it doesn't. I can't understand why this would be, as the only factor that's changed is speed - the angles are all the same. I'm a science ignoramus... so what am I missing? --Dweller (talk) 09:10, 3 September 2014 (UTC)

The faster you go between the ramp and the flat, the faster the transition rate. This will put a greater force on your front wheels, which will drive the front suspension further up, thus lowering your car. This could be enough to ground the oil sump. CS Miller (talk) 09:41, 3 September 2014 (UTC)

Ah, so you're saying that the speed I'm driving at can change the angles? Interesting, thanks. --Dweller (talk) 12:21, 3 September 2014 (UTC)

Your car may have a front air dam of questionable aerodynamic benefit. If the leading edge of your car has a strip of rubbery material that looks chafed, you can ask a workshop to remove it. Your car will go (if not win races) just as well without. 84.209.89.214 (talk) 12:40, 3 September 2014 (UTC)

I drive a fantastically oldmantypecar. The only spoilers I have are the damage to its bodywork. --Dweller (talk) 15:00, 3 September 2014 (UTC)

Right. The wheels of your car aren't rigidly connected to the body—you would have a really rough ride if they were! The wheels can travel vertically a modest distance relative to the body, limited by the travel in the suspension's springs and shock absorbers. If you head down the ramp at high speed, the wheels change direction - heading horizontally - while the body is still travelling downward (at an angle). The springs compress a bit as the body continues down, reducing the clearance under the vehicle: thunk! At lower speeds, the body has a smaller downward momentum, and the springs aren't compressed as much in the course of changing the body's direction. In some circumstances, you may also have better results if you hit the transition at an oblique angle, rather than straight on. (That is, so that one wheel at a time is making the transition from downhill to flat.) TenOfAllTrades(talk) 14:00, 3 September 2014 (UTC)

Gosh. I think I even understood that (except perhaps the bit about the wheels heading horizontally). Thank you. --Dweller (talk) 15:00, 3 September 2014 (UTC)

Because the floor on each level is horizontal, not inclined like the ramp. --65.94.51.64 (talk) 15:58, 3 September 2014 (UTC)

Main Battle Tank

How many M1Abrams tanks are still in service with the U.S Army ? 149.200.194.101 (talk) 11:37, 3 September 2014 (UTC)

According to List of currently active United States military land vehicles, 6344. --Jayron32 12:17, 3 September 2014 (UTC)

I wonder that although the gas turbine engine caused catastrophic consequences for the economy of the U.S , the army is still using the Abrams ? — Preceding unsigned comment added by 149.200.194.101 (talk) 15:23, 3 September 2014 (UTC)

is this satire?

Is this satire:

http://www.google.com/patents/US20060071122

Keep reading for a while. Is it satire the whole way through, and become obvious where it mentions the observers of the smoke experiment? (I'll let you read it.) THat's where I stopped reading.

Or, is it genuine on the part of the author.

If it is genuine: how can he construct meaningful-sounding, grammatically correct sentences like that?

(While mentioning the "Grey".)

If it is edited by a lawyer, why didn't he edit out at least that part?

I don't understand how anyone can write that earnestly. So, is it satire? Why was it granted?

I suggest you read it first, but the part where I stopped reading was the sentence beginning "It was this experiment". It makes the whole thing sound like a joke - not just pseudoscience and wrong. 213.246.165.17 (talk) 16:31, 3 September 2014 (UTC)