Wikipedia talk:WikiProject Physics/Archive December 2008

De Sitter invariant theories
De Sitter invariant theories is at WP:DRV undergoing deletion review 76.66.195.63 (talk) 02:16, 1 December 2008 (UTC)

New category: Energy in physics
Category:Energy was crammed with articles related to all aspects of energy, such as energy policies and power supply. To provide a home for the "pure" physics related articles, I created Category:Energy in physics, added the project template on its talk page, and I'm filling it right now. Please direct any discussion to Category talk:Energy in physics. &mdash; Sebastian 03:33, 30 November 2008 (UTC)


 * Some further discussion at Category talk:Energy makes me rethink my decision. I now feel it may make more sense to keep Category:Energy for the physics term, and create a different Category:Power and energy use for all the rest. &mdash; Sebastian 05:55, 4 December 2008 (UTC)

Quantum pseudo-telepathy
The new article Quantum pseudo-telepathy made it to "Did You Know". Whilst listed on the Main page, Quantum pseudo-telepathy was viewed on average once every 6 seconds. As a result, the article got quite some attention from a general audience, and consensus seems to be that it needs some "dumbing down". Just want to bring this to your attention, so that (hopefully) some subject matter experts get involved as well. Thanks, JocK (talk) 00:45, 5 December 2008 (UTC)

Giuseppe Cocconi
I significantly expanded the article on the late Cocconi (died 9 November 2008). If you have anything to added, don't be shy. I also didn't give an importance rating to his article since I wrote it, so feel free to assess it.Headbomb {{{sup|ταλκ}}κοντριβς – WP Physics} 07:13, 5 December 2008 (UTC)

Delaszk and relativity
is spamming literally a dozen articles with the claim that special relativity is simply a necessary consequence of Galilean relativity (more specifically that Galilean relativity implies a maximal speed). This is true only in the most generous sense that if one assumes there exists a maximum speed then that plus Galilean relativity implies Lorentz transformations, but Galileo obviously assumed there was no maximum speed (equivalent to c -> infinity). Delaszk also claims that the accelerating expansion of the universe (i.e. dark energy) follows from Galileo, which seems to simply be nonsense as far as I can tell.

The idea that Galilean postulates, by themselves, imply special/general relativity is WP:FRINGE as far as I can tell, but I'd appreciate it if others could be attentive to this editor's contributions. Dragons flight (talk) 16:25, 30 October 2008 (UTC)
 * This logical fallacy has been put forward by several people over the years and has been repeatedly refuted at Talk:Special relativity. Delete it on sight! JRSpriggs (talk) 17:47, 30 October 2008 (UTC)


 * And block user for a while (or give proper warnings if he didn't receive them etc...).Headbomb {{{sup|ταλκ}}κοντριβς – WP Physics} 18:04, 30 October 2008 (UTC)

JRSpriggs is accussing me of spam and vandalism. This is absolutely outrageous. If you disagree with the edits then say why. If you can't be bothered to do this or even link to where this has been discussed before then that is just lazy and uncivil. It is you who should be warned. Delaszk (talk) 18:11, 30 October 2008 (UTC)


 * Your statements lack references, and are completely false and this is obvious to anyone who passed an intro to special relativity class. See WP:FRINGE, WP:WEIGHT, WP:NOTABILITY, and WP:VERIFIABILITY. Headbomb {{{sup|ταλκ}}κοντριβς – WP Physics} 18:59, 30 October 2008 (UTC)

Hm, as I had suspected, people seem to get quite jumpy over this. With a little bit of mutual effort to establish a collaborative setting, I'm sure something could have survived here, although the essence is already sufficiently covered in subsection "From group postulates" and its closing statement. Pointing Delaszk to that section, providing some explanations, and a bit of plain talking might have prevented chasing him away. Reading the above I'm afraid it's too late now. Remember WP:DONTBITE and WP:AGF. Ah well, I tried. - DVdm (talk) 19:41, 30 October 2008 (UTC)


 * Someone who's been here for over 6 months isn't a newcomer. Science is not an endeavour where we have to try an salvage fringe pseudoscience because doing other will hurt someone's feelings. So no, "something" could not have survived because nothing from it was true or meaningful. Headbomb {{{sup|ταλκ}}κοντριβς – WP Physics} 19:58, 30 October 2008 (UTC)


 * Jumpy indeed :-|
 * I meant newcomer to the physics articles. Up to now Delaszk has been working on mathematics only. And I don't think that the closing lines of "From group postulates" are pseudoscience. I mean that with a bit of effort Delaszk could have been given an instructive lesson and might have become a valuable contributor to the physics articles. But of course no one can be forced to assume good faith. DVdm (talk) 20:08, 30 October 2008 (UTC)


 * Ok, upon further review, I take back some of what I said. I had a knee-jerk reaction since I thought Delask was some lunatic relativity denier. Now he may be that, but his recent edits are certainly cannot be called proof of that, and is most likely due to a misunderstanding of what Galilean transformations are. Galilean transformations are those of the type x'=x-vt and t'=t. What Delask is talking about is not Galilean transformation, but rather generalized linear transformations, of the form x'=ax+bt and t'=cx+dt, which include both Galilean transformations (a=1, b=-v, c=1, d=0) and Lorentz transformation (a=&gamma;, b=-&gamma;v/c2, c=-&gamma;v, d=&gamma;). That is not WP:FRINGE and everything else I said it was, and is in fact a common way to approach SR and the derivation of Lorentz transformations. But it is not a derivation from Galilean relativity. So I offer my apologies to Delask for jumping the gun. Headbomb {{{sup|ταλκ}}κοντριβς – WP Physics} 04:58, 31 October 2008 (UTC)


 * When I said Galilean relativity, what I meant was the principle of relativity, not the galilean transformations. Anyway the derivation of the Lorentz transformation does seem to imply a finite c without having to assume a finite c as a postulate. For details see here: Talk:Lorentz transformation/Archive 1. —Preceding unsigned comment added by Delaszk (talk • contribs) 13:31, 2 November 2008 (UTC)


 * Calling generalized linear transformations to be the "principle of relativity" is rather ambiguous and certainly very misleading as far as readers are concerned. And the Lorentz transformations do assume that c is finite; if c was assumed infinite, then you'd have Galilean transformations rather than Lorentz transformations.Headbomb {{{sup|ταλκ}}κοντριβς – WP Physics} 03:00, 3 November 2008 (UTC)


 * My initial edits on this topic were misleading because I did not fully understand the issue. As a result of the ensuing debate I have changed my argument somewhat. The point is that neither the Galilean transformations nor the Lorentz transformations can be ruled out using Galileo's principle of relativity. But the Galilean transformations can be ruled out by experiments involving high-velocities, and this is before anything has been said about light. The bit about the expanding universe, is that it may be the case that high-energy experiments could show that the Lorentz group should be replaced with a de Sitter group and hence the universe would be expanding. See de Sitter relativity. Delaszk (talk) 14:17, 26 November 2008 (UTC)

What Delaszk means is the following: The only possible symmetry groups which generalizes SO(3) to 4 dimensions and reduce to Galilean group at low velocities are SO(4) (rotations in 4d) and SO(3,1) (Lorentz group). SO(4) is ruled out as a symmetry of space-time, because then objects moving really fast would start going backwards in time, so it's SO(3,1). From the structure of the Lorentz group, you can deduce that there is a maximum speed. So to figure out relativity you only need the principle of relativity plus "it's not like you think". There's only one other choice.Likebox (talk) 06:20, 6 December 2008 (UTC)
 * To Likebox: Is there not a third alternative? The group of matrices of the form

\begin{bmatrix} Rot & Trans \\ 0 & 1 \end{bmatrix} $$
 * where Rot is in the group of rotations SO(3) and Trans is a 3-vector in R3. This is the group of Galilean-Newtonian space+time, i.e. the Galilean group itself. JRSpriggs (talk) 06:46, 6 December 2008 (UTC)
 * The Galilean group is not the third alternative, the Galilean group is the first alternative, it comes before either of the above two groups. So you need principle of relativity plus "what went before ain't right". Nothing about light, nothing about maximum speed. Delaszk (talk) 14:43, 6 December 2008 (UTC)

De Sitter relativity at AfD
De Sitter relativity has been nominated for deletion 76.66.195.63 (talk) 06:54, 24 November 2008 (UTC)
 * It seems that, who wrote this article, has been adding a lot of questionable information about (special) relativity to wikipedia lately. See also the section Wikipedia talk:WikiProject Physics. JRSpriggs (talk) 20:58, 24 November 2008 (UTC), redacted by User:LessHeard vanU 13:30, 28 November 2008


 * I understand your frustration with people editing articles on topics that they don't understand and persisting with it. However, calling other editors a crank does not help. It does not matter whether you couch that statement in weasel words. Why don't you remove the first sentence? Surely it's enough to say that Delaszk has been adding questionable information. -- Jitse Niesen (talk) 11:43, 28 November 2008 (UTC)


 * My first edits on special relativity a few weeks ago were misleading and they have been deleted. I have taken notice of what other editors have said and my more recent edits on the topic have reflected that.


 * But this issue is about the article de Sitter invariant theories (previously titled de Sitter relativity) under deletion discussion. The quality of some of the edits I have previously made is not pertinent to the question of notability of the topic google hits for de Sitter invariant. If JRSpriggs has anything to say about that topic he should say it on the AfD page. JRSpriggs has indulged in a pattern of inflammatory language about this from the beginning. Prior to this AfD our last encounter was a discussion in which he argued against time measured in metres and then gave up when he realized that time in metres is possible. But that's no reason to abandon that time-in-metres discussion and then wait for an opportunity to sabotage an article I created. Delaszk (talk) 12:35, 28 November 2008 (UTC)
 * To Delaszk: I am sorry that my comment offended you. However, please let me correct a point in what you have said. I did not realize "that time in metres is possible" when one is in a Galilean-Newtonian space+time (i.e in the absence of the second postulate). It is not possible. I simply chose not to respond, as is often the case, because my time available for working on Wikipedia is limited and I am watching about 200 articles. Also I was not trying to specifically influence the AfD, but merely making a more general comment. JRSpriggs (talk) 06:00, 29 November 2008 (UTC)
 * My original posts weren't accurate, but the main point about deriving the theory without making prior assumptions on light was accurate and Markus Poessel agreed on this. Certainly in Newtonian world there is no unique way of defining time in metres but that doesn't stop you using the concept of arclength of a clockhand to describe an interval during which things happen. Delaszk (talk) 19:07, 4 December 2008 (UTC)
 * Talking about "maximum speed" rather than "speed of light" does not obviate the necessity of having a second postulate. You still need to say that there is a finite maximum speed in addition to saying that the laws of physics are invariant when one changes the speed of the observer. Of course, the arc-length can be used to describe the interval, but that is changing the meaning of your claim that "The transformations are then derived using just the principle of relativity and have a maximal speed of 1, ..." which implicitly assumes that the way of measuring time in meters is by using the maximal speed to do the conversion. JRSpriggs (talk) 04:14, 5 December 2008 (UTC)
 * But you don't need to postulate the maximum speed. The maximum speed is built-in to the transformations. If you exceed the maximum speed then the transformations don't make physical sense.
 * The derivations from relativity gives you a choice of Galilean or Lorentz and all you have to do is rule out the Galilean transformations by accurate or high velocity experiments. As for the taiji transformations - the maximal speed of 1 comes from the form of the derived equations not from an assumption. But anyway I used the taiji stuff as an example of single postulateness but that was not the authors main reason for using this formulation. They did things that way as a starting point for introducing practical ways of doing relativistic many-body calculations, amongst other things. Delaszk (talk) 10:51, 5 December 2008 (UTC)
 * But in order to know that using "the taiji stuff" is legitimate, you have to already know that the transforms are Lorentz and not Galilean, so finite maximum speed is a requirement of it, not a consequence. As for whether you use two postulates or one postulate and something else, that's arbitrary; Einstein did the former in the first 1905 paper, but the latter – with the "something else" being the form of Maxwell's equations – in some later paper. But knowing that the maximum speed is finite (either by "accurate or high velocity experiments", or by the form of some particular physical law) doesn't follow by postulating the principle of relativity alone. So the second option is actually "one postulate and experimental data", or "one postulate and the form of Maxwell's equations" (or whatever physical law), not "one postulate and nothing else". -- Army1987 (t — c) 12:01, 6 December 2008 (UTC)
 * Regarding the taiji stuff - The derivation of the taiji transformations should not be confused with the derivation of the Lorentz transformations. In the taiji setup with all 4 coordinates of spacetime measured in the same units, the taiji transformations are the only transformations that come out. You can't get anything like the Galilean transformations out of the taiji formulation. Using Maxwell's equations allows you to convert between taiji time in metres with dimensionless speed and conventional time in seconds with speed in m/s. You don't have to know that the transforms are already Lorentz. If special relativity had been discovered by this route then people would have said: hmm ... time in metres sounds weird, but the theory fits with experiments better than Newtonian dynamics. So it would have been accepted just as Einstein's formulation was.
 * Regarding the single postulate stuff - Knowing that either the Galilean or the Lorentz are consistent with the principle of relativity, to get the Galilean transformations you must do inaccurate experiments. So to go from Galilean to Lorentz you just need more accurate experiments. That's not extra information, that's the just same information measured more accurately. Delaszk (talk) 14:05, 6 December 2008 (UTC)
 * As for the taiji stuff, you can only measure time and space with the same units hoping that the result is invariant under those transformations if there is a God-given universal speed to use as a conversion factor. So it is a prerequisite, not a consequence. In a Galilean world there would be no meaningful way to measure time in metres. As for the single postulate stuff, what you say is true, but experimental data do not pop out of postulates; so "you need more accurate experiments" means "you need something more than a postulate", as experiments are something more than a postulate. -- Army1987 (t — c) 14:18, 6 December 2008 (UTC)

Grammar, etc.

 * The Great Formula says:
 * a = b + c.
 * Where a is the number of rabbits...
 * Where a is the number of rabbits...
 * Where a is the number of rabbits...

Are physicists actually taught to write like this, putting a period at the end of the formula and capitalizing the "W" as if it's the beginning of a sentence rather than part of the same sentence? I keep seeing that in physics-type articles.

Is this correlated with the hostility physicists often express for precise definitions and the like? Michael Hardy (talk) 20:24, 3 December 2008 (UTC)


 * Physicists as group are not really taught to write in any particular way, at least not in my experience. That is, I never took a physics class on writing, nor have I heard of one. But it's pretty common to put proper punctuation after an equation. I agree that the above is poor writing. I would have used a comma instead of a period and not capitalized the "W". As to your final comment, physicists are happy with precise language, as long as it doesn't get in the way. Context is the key. Joshua Davis (talk) 20:59, 3 December 2008 (UTC)


 * I took a math class in high school where the teacher told us that every equation should be part of a complete sentence with correct grammar, punctuation, capitalization, and so forth, keeping in mind that "=" is a verb, "+" is a preposition, etc. That was a really great teacher, and I agree with Joshua that most scientists (sadly) are never formally taught or tested on equation-related grammar. Luckily, even without formal instruction, most (but not all!!) scientists seem to be able to figure it out themselves. :-) --Steve (talk) 01:36, 4 December 2008 (UTC)
 * So this is a style issue somewhat, but it really really grates on me when people put periods at the end of displayed math, even when it is the end of a sentence. It strikes me as the same as putting periods inside quotation marks, when the quoted text does not end in a period.  It's sort of a use–mention confusion.
 * Logically the period should go at the start of the next line (undisplayed). Unfortunately that is not a style in wide diffusion.  So next best (or next least bad) is simply to omit the final period entirely, when the sentence ends with displayed math.  This will hardly ever cause confusion, whereas a period just might, because someone could try to interpret it mathematically. --Trovatore (talk) 01:42, 4 December 2008 (UTC)
 * Interesting point. However, since it's a near-universal convention, Wikipedia is somewhat compelled to follow it. How about putting periods at the end of displayed equations...except in the rare cases when it would cause confusion, (like "a=b+.3.") and there's no simple way to rewrite the equation so that it wouldn't cause confusion (like "a=.3+b." or "a=(b+.3).")? --Steve (talk) 02:20, 4 December 2008 (UTC)
 * With leading zeroes, italics and spaces that's not very confusing: a = b + 0.3. Looks clear enough to me. -- Army1987 (t — c) 11:51, 6 December 2008 (UTC)
 * Nothing's ever really been said in classes about how to write with equations, but in science journal, I've always seen in done in this way:"This leads to the relation A=B+C, where A represents something, B another thing, and C something else." or similar ways. On wiki, I follow WP:MOSMATH, with I find to make a ton of sense.Headbomb {{{sup|ταλκ}}κοντριβς – WP Physics} 02:55, 4 December 2008 (UTC)


 * The journal manuals of style I've seen generally say equations should make sense as parts of complete sentences, and so should be punctuated accordingly. Very commonly that means you need a comma or a period after an equation, but the important thing is that it make sense grammatically.  There is also an ancient weird confusion about the order of quotation marks and other terminal punctuation, that I think goes back to typesetters' mechanical problems with isolated slivers of type metal, but which has become the stylistic norm and has endured even though it no longer makes any sense (and never did, grammatically or logically, as far as I can see).  If I recall it would have us, eg, put a quote after a period, even when logically it makes no sense -- as in, say:  "The teacher preferred 'had had' to 'had.'"


 * Personally, I try to follow logic and grammar except when some copy-editor with M.O.S. in hand demands otherwise, but it only really matters when the meaning is actually liable to be misunderstood—which is rare, luckily Wwheaton (talk) 04:18, 4 December 2008 (UTC)


 * "...the important thing is that it make sense grammatically..." :-)
 * The weird reversal of punctuation with double-quotes has survived on this side of the Atlantic; this is one of the very few cases where I prefer the choice made by our English friends. That, and judg(e)ment — the American spelling looks unpronounceable. --Trovatore (talk) 05:52, 4 December 2008 (UTC)

Energy functional
I added an example of the energy functional to the functional (mathematics) quite sometime ago. However I was and still is surprised that WP does not have an article on the energy functional, even though I have seen use of this term in many places. I am not a physicist to write a comprehensive article on this topic, but I thought to let you know that it was linked to a description of optimization (mathematics). I created a stub, I may come back later to check on progress and add references if I can find any. (Igny (talk) 02:06, 6 December 2008 (UTC))
 * Perhaps you should redirect it to Hamiltonian mechanics or Hamiltonian (quantum mechanics) since "Hamiltonian" is what the energy functional is usually called. JRSpriggs (talk) 05:41, 6 December 2008 (UTC)


 * You probably mean something like this, I was thinking about something like that. (Igny (talk) 16:04, 6 December 2008 (UTC))
 * Although the notation is significantly different, I believe that the basic idea is the same. You could add some examples like those in the wikiversity article to Hamiltonian mechanics and then redirect to that. JRSpriggs (talk) 16:45, 7 December 2008 (UTC)
 * I was thinking about a standalone article with hamiltonian as one example. I have seen other examples as well, different problems, like image recognition for example, with Mumford-Shah energy functional. (Igny (talk) 01:47, 8 December 2008 (UTC))

I have expanded the stub a bit, but like I said I lack physics background to write more coherent prose. (Igny (talk) 01:14, 14 December 2008 (UTC))

Gravitation
Could someone please have a look at Talk:Gravitation, User:Logicus seems insistent on removing the 1919 Eddington eclipse from the article, saying that it did not confirm the prediction of general relativistic gravitational deflection, or, at least, that it did not disconfirm the Newtonian corpuscular theory. To the best of my own understanding (and that of several eminent astronomers), the Eddington expedition did indeed confirm Einstein's theory and disconfirm Newton's. Would someone with more experience, either in astronomy or in the history and philosophy of science, please investigate User:Logicus's point of view. I'm not interested in getting into an argument, but that seems to be Logicus's chief aim. siℓℓy rabbit (  talk  ) 00:23, 9 December 2008 (UTC)
 * I hate to say it, but User:Logicus seems to have a contentious editing history.  The 1919 Eddington eclipse observation was certainly accepted as confirmation at the time (1919), and made "Einstein" a household name overnight.  I am not expert enough to have a valid opinion either way, but would not remove the common wisdom since then without a new consensus clearly against the old story.  Wwheaton (talk) 05:52, 14 December 2008 (UTC)

Spin-½
Is there any reason that this is not a simple redirect to fermion?Headbomb {{{sup|ταλκ}}κοντριβς – WP Physics} 04:29, 14 December 2008 (UTC)


 * Well first of all fermions are particle with half-integer spins not just spin-1/2. The article on spin-1/2 should probably focus more on the particularities of a spin-1/2 system. For example spin-1/2 systems have only two states making then the easiest quantum system we can study. This in part explains the popularity of spin-1/2 in toy models such as the Ising model of exactly solvable models for decoherence.
 * Secondly, spin is a property that inherently is unconnected to that of being a fermion. The spin-statistics theorem is a non-trivial result with non-trivial assumptions. Non-local theories for example do not need to obey it and could for example have spin-1/2 bosons. This is the case for some proposed quasi particles used for models for type II superconductivity. (if I recall correctly)
 * So no spin-1/2 should not be a redirect to fermion. (TimothyRias (talk) 08:00, 14 December 2008 (UTC))

FAR
nominated Hubble Deep Field for a featured article review here. Please join the discussion on whether this article meets featured article criteria. Articles are typically reviewed for two weeks. If substantial concerns are not addressed during the review period, the article will be moved to the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Remove" the article's featured status. The instructions for the review process are here. &mdash; Ceran '''[  speak  ] 19:33, 14 December 2008 (UTC)

WP:PROD
Noninertial reference frames and Exceptional Universe have been PRODed. 76.66.195.159 (talk) 07:55, 15 December 2008 (UTC)

I tagged Exceptional Universe for speedy deletion. Noninertial reference frames should be merged with Non-inertial reference frame, but most of the content on either articles are in dire need of complete rewrites.Headbomb {{{sup|ταλκ}}κοντριβς – WP Physics} 08:37, 15 December 2008 (UTC)

Assessment update 15 December 2008
Assessment progression graph

Keep up the good work people.Headbomb {{{sup|ταλκ}}κοντριβς – WP Physics} Headbomb {{{sup|ταλκ}}κοντριβς – WP Physics} 02:17, 16 December 2008 (UTC)

Submitting List of baryons for mainpage
I want to submit List of baryons to be displayed on the mainpage. If those with a background go through the list once more to make sure the physics are right / correct there where appropriate (I'm especially concerned about the section on parity), that would be much appreciated, and that all that needs to be said is said.Headbomb {{{sup|ταλκ}}κοντριβς – WP Physics} 02:20, 17 December 2008 (UTC)


 * I'm also considering merging the list with Baryon since most of the content, other than the list itself, should also be in the baryon article.Headbomb {{{sup|ταλκ}}κοντριβς – WP Physics} 03:43, 17 December 2008 (UTC)


 * I think the section on parity gives the wrong definition. I proposed a rewrite for that section on the talk page. :-) --Steve (talk) 04:38, 17 December 2008 (UTC)

Energy
I have not been on Wikipedia to quite long enough to know how this works. But I have noticed that the article on Energy seems to get some regular vandalism from ip users. I have also noticed some pages are semi-protected. Is it possible/sensible to have the page on Energy semi-protected? Thenub314 (talk) 19:04, 19 December 2008 (UTC)
 * By today's standards the level of vandalism is low. However I noticed one vandalism-only account User_talk:Bob sass, which I blocked indefinitely. Ruslik (talk) 21:53, 19 December 2008 (UTC)

Simple resolution to baryon asymmetry
I was just thinking: 1. Matter is anti-matter, but moving backwards through time. 2. If, at the big bang, matter (feynman arrows) leave that point in all directions, shouldn't they be pointing backwards through time, too? And, in every other direction? 3. Isn't the matter-antimatter discrepancy explained by this simple observation? Also, wouldn't this explain galaxies which appear too old and far away to be possible? Someone please help me on this. It all seems so simple. (cringe) Phlack (talk) 06:13, 17 December 2008 (UTC) After further thought, this easily explains the red shift and apparent expansion of the universe. Please help, I feel like I'm an idiot and I'm missing something. Phlack (talk) 06:18, 17 December 2008 (UTC)


 * When you figure it out, tell us. You'll probably end up having a Nobel prize. Headbomb {{{sup|ταλκ}}κοντριβς – WP Physics} 07:45, 17 December 2008 (UTC)

I wish you hadn't linked me to that page. I think I can explain the cosmological constant AND asymmetrical baryogenesis with one go. Imagine the big-bang as a two-dimensional phenomenon, with time as the third dimension. What shape does this have? If particles were expanding outward at close to the speed of light, it would look like a cone. Here's what brought me to this conclusion: How often do you see cones in nature? If you think of the big-bang as a more natural, four-dimensional expansion in all directions from the point of origin, suddenly, the red-shift of distant galaxies is only a consequence of the different angle from the origin (i.e., speed/redshift). Additionally, this removes the need for a cosmological constant: the distribution of the force of gravity creates a balance around the entire four-dimensional sphere. Can somebody with more math skill than me figure out a way to test this hypothesis? By computing the distance from the temporal center of the universe (13 billion light years?), couldn't you calculate the predicted red-shift and coordinates of distant objects? Is this testable using existing data? I'm losing sleep over this. Any help is appreciated. I would kill for someone to disprove this right now using simple physics or math.

Phlack (talk) 23:54, 17 December 2008 (UTC)


 * I'm afraid your ideas aren't coherent enough to be testable. At best you're thinking of a big bang geometry drawn in such a way that the cosmological time increases radially instead of vertically, as in this image from Ned Wright's cosmology tutorial. It's not a new theory, it's just another way of drawing the same spacetime that's shown in this image and this image and this image and many others. There's more to big bang cosmology than a vague idea of things flying apart. ΛCDM survives because it fits the data, not because theorists can't think of anything more elegant. The simpler models have been ruled out. Being elegant isn't helpful; you have to crunch the numbers, and there are a lot of numbers to crunch. You need to understand all of this before you can hope to contribute to cosmology. I recommend starting with Ned Wright's tutorial. -- BenRG (talk) 06:48, 21 December 2008 (UTC)

When did the quark epoch occur?
Timeline of the Big Bang says "Between 10–12 seconds and 10–6 seconds after the Big Bang", QCD matter says "when the universe was only a few tens of microseconds old". How comes the discrepancy of an order of magnitude? (Even admitting there is a huge uncertainty on when it ended, "a few tens of microseconds" seems to exclude times such as 10−9 seconds and the like – should it be "until" rather than "when"?) -- Army1987 – Deeds, not words. 12:03, 20 December 2008 (UTC)

Template for members
Just copy this on the top (or bottom) of your user page Physics Member Navbox and you'll get this neat navbox to help you get around WP physics. I'll add some more links overtime. Headbomb {{{sup|ταλκ}}κοντριβς – WP Physics} 12:15, 19 December 2008 (UTC)


 * I've tweaked it so that the current activity appears on two columns. -- Army1987 – Deeds, not words. 11:48, 21 December 2008 (UTC)

Physical chemists and AnomieBOT
I noticed that AnomieBOT has tagged all of the articles in Category:Physical chemists with physics tag. (I particularly noticed this because it put the physics tags back onto a few articles I'd removed them from!) I've re-removed them - any objections? Djr32 (talk) 20:01, 20 December 2008 (UTC)

Not at all. I told the bot to tag all members of Category:Physicists and many subcategories. The point was more too make sure that we review all legit physicists candidates than anything else. The bot-tagged articles don't have any importance ratings, so it's fairly easy to. Remove away!Headbomb {{{sup|ταλκ}}κοντριβς – WP Physics} 10:30, 21 December 2008 (UTC)

TeXnicalities
Why do I freqently see things like x^{2} or a_{2} rather than x^2 and a_2 within TeX in articles on physics? The inclusion of the needless braces doesn't change the appearance but may lead newbies to think those are needed. (Of course they are needed when more than one character is to be included in the superscript or subscript, as in x^{22}, but not in these simple cases.) Michael Hardy (talk) 05:26, 21 December 2008 (UTC)


 * Probably either because newbies think they need them, or because someone puts them by force of habit. Not very important either way, since stuff gets display accuratly.Headbomb {{{sup|ταλκ}}<sub style="margin-left:-3.5ex;">κοντριβς – WP Physics} 10:31, 21 December 2008 (UTC)

Work output
I have a feeling this could be merged somewhere, but its possible than it warrant its own article. What do you think?Headbomb {{{sup|ταλκ}}<sub style="margin-left:-3.5ex;">κοντριβς – WP Physics} 13:50, 21 December 2008 (UTC)
 * For now I think it'd better redirect to work (physics); in the unlikely event that a disproportionate amount of stuff is written about that particular concept, it can always be split back. --17:10, 21 December 2008 (UTC)

Sociology??
The article titled Weinberg–Witten theorem is a horrible mess. It begins with this sentence:
 * Steven Weinberg and Edward Witten consider the so-called emergent theories to be misguided.

This doesn't tell the reader whether this article is about sociology, economics, psychology, biology, literary criticism, linguistics, or whatever.... You've read all the way through the first sentence and you still don't know that.

The phrase Weinberg–Witten theorem doesn't even occur until several sections into the article. And lots of other "issues" afflict it. It's a horrible mess. Please help. Michael Hardy (talk) 05:24, 24 December 2008 (UTC)

Theoretical Parallel Universes
Theoretical Parallel Universes has been sent to AfD. (It looks like someone's personal understanding of MWI) 76.66.195.159 (talk) 08:04, 24 December 2008 (UTC)

Thermodynamic beta
Again, this is an article I feel should be merged, but can't figure out where it would be best to put it. Headbomb {{{sup|ταλκ}}<sub style="margin-left:-3.5ex;">κοντριβς – WP Physics} 20:20, 24 December 2008 (UTC)


 * Seems like 99% of it is a proof (in statistical mechanics) that two energy-exchanging systems will acquire the same temperature. The other 1% is the one-sentence definition: β=1/(kBT). Clearly the 99% part doesn't belong there, it belongs in a separate article linked from temperature, or maybe a subsection of zeroth law of thermodynamics, or something like that. The one-sentence definition of beta could be an unusually short article, or just stuck somewhere in temperature. Just some thoughts, I dunno. --Steve (talk) 02:38, 26 December 2008 (UTC)


 * Maybe a merge with thermodynamic temperature then (which IMO, should be merged with Temperature)?Headbomb {{{sup|ταλκ}}<sub style="margin-left:-3.5ex;">κοντριβς – WP Physics} 21:35, 26 December 2008 (UTC)

Problematic physics experiments
I'm thinking of submitting this to AfD, but I'd rather have feedback first. I'm having some hesitation because the content here is good, but the title make the article impossible to "complete". Toughts? Headbomb {{{sup|ταλκ}}<sub style="margin-left:-3.5ex;">κοντριβς – WP Physics} 21:35, 26 December 2008 (UTC)

Gauge gravitation theory
Gauge gravitation theory has been sent to AfD for deletion. 76.66.195.190 (talk) 05:59, 27 December 2008 (UTC)

Newton
nominated Isaac Newton for a featured article review here. Please join the discussion on whether this article meets featured article criteria. Articles are typically reviewed for two weeks. If substantial concerns are not addressed during the review period, the article will be moved to the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Remove" the article's featured status. The instructions for the review process are here. -- Redtigerxyz Talk 15:27, 27 December 2008 (UTC)

Terminal velocity (derivations)
Terminal velocity (derivations) has been sent to AfD for deletion. 76.66.198.171 (talk) 07:20, 29 December 2008 (UTC)

Indeterminacy problem
Has anyone heard of this? I've nominated the article for deletion. -- Army1987 – Deeds, not words. 12:04, 30 December 2008 (UTC)

7d Physics at AfD
The article seems to be complete OR. For as far as the ideas themselves go, it seems to be just a particular case of Kaluza-Klein theory. (TimothyRias (talk) 15:59, 30 December 2008 (UTC))

Electron hole
Hi. My first visit here. One new wiki experience for me.

I'm concerned with the article title Electron hole. I haven't seen this term used anywhere except the Wikipedia and derivations thereof. I think the correct term is Hole but it needs disambiguation if it is to be the title. I considered moving the article to Hole (solid state physics) but then I had second thoughts because this may not be the proper or best way to disambiguate it. Some other alternatives would be Hole (charge carrier) or Hole (quasiparticle). I'd be interested in others' thoughts and suggestions regarding this. Thank you. --Bob K31416 (talk) 17:17, 30 December 2008 (UTC)


 * How 'bout Hole (physics and chemistry)? -- Army1987 – Deeds, not words. 17:26, 30 December 2008 (UTC)


 * Yes the term always struck me as odd on wiki. I never changed it, but I think it should. Hole (semiconductors) seems a natural fit shoe-in to me, but Hole (charge carrier) and others might also do the job.Headbomb {{{sup|ταλκ}}<sub style="margin-left:-3.5ex;">κοντριβς – WP Physics} 17:59, 30 December 2008 (UTC)


 * One thing I'm uncertain about is using a disambiguator like "solid state physics", "physics and chemistry", or "semiconductors",    because a hole is neither of these. Whereas a hole is a "charge carrier" or a "quasiparticle". So it's partly a matter of my ignorance of Wikipedia naming conventions as to what is preferred or allowed. --Bob K31416 (talk) 21:14, 30 December 2008 (UTC)

Oh, and welcome on the Physics Project. If you have any question just ask 'em here or contact any of us on our talk pages and we'll do our best to help you.Headbomb {{{sup|ταλκ}}<sub style="margin-left:-3.5ex;">κοντριβς – WP Physics} 18:00, 30 December 2008 (UTC)
 * Thanks! --Bob K31416 (talk) 21:14, 30 December 2008 (UTC)

Based on this section, I have started a discussion at Talk:Electron hole. - Eldereft (cont.) 01:26, 31 December 2008 (UTC)

Phenomenological thermodynamics at AfD
Anyone ever heard the phrase used? Djr32 (talk) 18:59, 30 December 2008 (UTC)


 * I've never encountered anything like that. Granted I'm a master's student, so I can't say there's not such things, but that really sounds to me like something that a single author wrote because he dabbled in philosophy.Headbomb {{{sup|ταλκ}}<sub style="margin-left:-3.5ex;">κοντριβς – WP Physics} 03:48, 31 December 2008 (UTC)


 * From the article in question, "Generally, phenomenological thermodynamics, being synonymous with classical thermodynamics...". It looks like the originating editor got confused or something and started a new article instead of editing the existing article Classical thermodynamics. --Bob K31416 (talk) 06:09, 31 December 2008 (UTC)


 * Your contributions at the AfD article would be useful! I suspect that most people contributing there are not experts in this field.  Djr32 (talk) 14:57, 31 December 2008 (UTC)

Peer review for vector spaces
The vector space article has recently passed its Good Article nomination. I think it has a reasonable state and I'd like to get broader input, especially on accessibility, balance and completeness of the article for a possible FA nomination, so I am nominating it for Peer Review. Thanks for the review, Jakob.scholbach (talk) 14:40, 31 December 2008 (UTC)