Wikipedia talk:WikiProject Physics/Archive July 2010

Universe (2)

There's an ongoing edit war at Universe (edit | talk | history | protect | delete | links | watch | logs | views), with an IP repeatedly re-adding the same text. I invite all editors with expertise in cosmology to take a look at the recent edit history and make any adjustments they see fit. I'm reluctant to take further action as I've already reverted once, and there aren't enough editors involved to have established what consensus is. --Christopher Thomas (talk) 04:57, 2 July 2010 (UTC)

This is ongoing, with contested material now being about the anthropic principle. There is a discussion thread at talk:universe#Anthropic principle "untestable"?. I invite anyone with expertise to review the thread and add whatever comments they see fit. Quite a lot of the article could use an editing pass too, but that's a can of worms I'm not in position to open at the moment. --Christopher Thomas (talk) 22:45, 4 July 2010 (UTC)

At the suggestion of User:Chetvorno, I've set up a straw poll at Talk:Universe#Straw poll on anthropic principle and fine-tuning, to determine consensus on presentation of fine-tuning and anthropic principle arguments in the article. Right now the debate is getting loud and uncivil. Please take a moment to look at the straw poll and either endorse or not endorse an article version as you see fit. --Christopher Thomas (talk) 19:24, 5 July 2010 (UTC)

List of atmospheric radiative transfer codes

Hi, I'm doing a major revision of List of atmospheric radiative transfer codes (see Talk:List of atmospheric radiative transfer codes and recent history). I would like some help, particularly because I have some conflict of interest and I am not an expert on Wikipedia. Thanks. --Gerrit ^CUTEDH 14:57, 5 July 2010 (UTC)

Move of tauon, tauon neutrino to tau (particle), tau neutrino

Recently a proposal was made to move tauon to tau (particle) and tauon neutrino to tau neutrino. This was passed and the pages moved, only to be reverted back within 24 hours by a single dissenting editor who did not open another move discussion. I have therefore reopened this discussion here. Icalanise (talk) 17:59, 28 June 2010 (UTC)

That is an inaccurate summary of the situation. I'll leave it at that. Headbomb {talk / contribs / physics / books} 18:34, 28 June 2010 (UTC)

Please explain where in my above summary I am inaccurate. "Recently a proposal was made to move tauon to tau (particle) and tauon neutrino to tau neutrino." [1]. "This was passed" [2] "and the pages moved" [3] "only to be reverted back within 24 hours" [4] "by a single dissenting editor" (evidence that the editor dissents [5]) "who did not open another move discussion" [6]. "I have therefore reopened this discussion." [7]. I fail to see what is to object to here. Fact is the move was closed as a pass, the fact that you disagree with that result does not change that fact. In fact I disagree that there was a consensus there too, but reverting the move without reopening the discussion is also something that should not have happened. Icalanise (talk) 18:43, 28 June 2010 (UTC)

As far as I can tell from reading the talk page, there was no consensus in any of the three either of the two move discussions for making the move. The move should not have been performed. --Christopher Thomas (talk) 18:40, 28 June 2010 (UTC)

I certainly had the impression that "tauon" was the correct term, by analogy with "muon". JRSpriggs (talk) 09:25, 29 June 2010 (UTC)

It once was, but I'd been under the impression that that usage was now historical, and the evidence presented by others at the latest move thread seems to back that up. By all means comment at that thread, though. --Christopher Thomas (talk) 18:36, 29 June 2010 (UTC)

It's not historical, it's just not part of "every day speech" amongst particle physicists, much like "mu" and "nu e" are everyday speak for muon and electron neutrino. Headbomb {talk / contribs / physics / books} 09:53, 7 July 2010 (UTC)

Category:Ultraviolet

FYI, Category:Ultraviolet is up on WP:CFD for renaming, or splitting, or something else (that's the nomination). 76.66.192.55 (talk) 04:52, 10 July 2010 (UTC)

hot companion

FYI, hot companion has been sent for deletion via AfD. As there is some astrophysics involved, you might like to know. 70.29.212.131 (talk) 23:50, 19 June 2010 (UTC)

Wikipedia:Articles for deletion/Hot companion - it survived AfD, now what to do with it? 76.66.195.196 (talk) 05:02, 26 June 2010 (UTC)

If, as the AfD comments suggest, it's widely used, we should be citing places it's used. If, as the comments suggest, it's widely used meaning several different things, then it would be best to turn the page into a disambiguation page with links to relevant articles that cover the meanings (and citations to articles using the term for different things). Either way, this would be best handled on talk:hot companion, assuming enough interested parties are directed there. Perhaps ask at WP:AST/WP:ASTRO for more specific advice. --Christopher Thomas (talk) 08:33, 26 June 2010 (UTC)

WT:ASTRO has come to the conclusion it is a trivial term, a simple combination of an adjective "hot" with a noun "companion". 76.66.193.119 (talk) 06:37, 16 July 2010 (UTC)

Peer review for Physics article

See Wikipedia:Peer review/Physics/archive1. ― A._di_M.^{3rd Dramaout} (formerly Army1987) 18:29, 11 July 2010 (UTC)

Could someone doublecheck my revert?

I reverted this as nonsense. However, I want to make sure I'm not undoing something that is merely poorly phrased, so if someone could double check that revert, that would be appreciated. Headbomb {talk / contribs / physics / books} 09:50, 7 July 2010 (UTC)

The IPs addition to Koide formula didn't make much sense to me either. They have a history of adding rambling essays to other articles (most frequently to Everything). This is likely more of the same. --Christopher Thomas (talk) 19:27, 7 July 2010 (UTC)

Revert is correct. Xxanthippe (talk) 11:05, 16 July 2010 (UTC).

Kerr-Schild metric

Sorry, do you need a translation from the italian page of the Kerr-Schild metric?? While I was surfing the net I have noticed that this page was missing, do you know where I could find an alternative page (if it does already exist, but with another name---). Thanks you all. Tell me if you need some translations from italian. Bye Danieldoz (talk) 17:10, 15 July 2010 (UTC)

The closest article seems to be Kerr-Newman metric#Alternative (Kerr-Schild) formulation. --Christopher Thomas (talk) 17:56, 15 July 2010 (UTC)

Aha, ok, perfect! If you want, I can add some info about when was it done or sth like this. If u would like to have a preview, just write me... I think it is the same thing, but I don't actually know if you need a new page... If u want I can add some infos... ByeDanieldoz (talk) 11:36, 16 July 2010 (UTC)

Book:Quarks and Book:Leptons

I recently created these two books and it would be nice to have someone verify that I haven't forgotten to include certain articles. Headbomb {talk / contribs / physics / books} 14:25, 15 July 2010 (UTC)

Well it seems that User:Headbomb and I are having a dispute over the use of the terms "tauon" and "tauon neutrino" in the leptons book. Headbomb regards the distinction of tauon/tau and tauon neutrino/tau neutrino to fall under WP:ENGVAR, and thus since he put tauon and tauon neutrino into the article, that is how it must remain. I'm not convinced this falls under the scope of WP:ENGVAR at all (as this is not to do with regional variants of English), and there is discussion at Talk:Tau (particle) indicating a consensus for tau/tau neutrino. Having a third party take a look at this would be useful. Icalanise (talk) 17:05, 18 July 2010 (UTC)

WP:ENGVAR proper applies to national varieties, but the principle of not switching equivalent styles for the sake of it is more general: see WP:MOS#Stability_of_articles. A. di M. (formerly Army1987) (talk) 18:28, 18 July 2010 (UTC)

On the other hand I am not so convinced it should apply to preserving variants of article titles for Wikipedia Books. As I understand it, the books are a way of getting a group of related articles as a PDF or as an ordered hardcopy. Thus it seems rather odd to use WP:ENGVAR or article stability to go against a consensus decision on the naming of the articles in a Wikipedia book. Icalanise (talk) 19:19, 18 July 2010 (UTC)

Incidentally it is interesting that no-one brought up WP:ENGVAR during the move discussions. I would have thought that given the editor's insistence on using it to preserve the use of "tauon" and "tauon neutrino" in the articles themselves, that they would have used it to oppose the move... Icalanise (talk) 19:23, 18 July 2010 (UTC)

Anon edits at Quantum chaos

Quantum chaos has been recently edited (diff) by 85.85.104.70 (talk · contribs). The edits seem, based on a pattern of editing, to be WP:COI violations: the user adding his own non-peer-reviewed sources to many articles. But I'm not a physicist, and it's possible that I've erred in my judgment. Would someone review this addition?

CRGreathouse (t | c) 17:35, 17 July 2010 (UTC)

Superbradyon

I'm concerned that this article was never merged, as an AfD decided in 2008. Whether it should have been or not, I'm also concerned with the fact that it is almost entirely based on one man's works. Could someone perform the merge as was directed then, or perhaps clean up the article (find more references outside of his work and other miscellaneous cleanup)? --Izno (talk) 16:43, 22 July 2010 (UTC)

Sagnac effect edits

I've noticed that someone tried to rewrite the articles on Georges Sagnac and Sagnac effect, to give the impression that the Sagnac effect is "not" consisted with relativity (see diff and diff). I've reverted those edits and expanded the history sections. Maybe other editors should take care of those articles as well. --D.H (talk) 18:28, 22 July 2010 (UTC)

Additions that could use vetting/cleanup

An enthusiastic but inexperienced IP editor has been active across several science articles. Most of their changes ended up reverted, one was fine as-is, but two could use more detailed attention (they need to be pared down, sourced, and merged, and I'm not in a position to do that tonight):

• this edit to Alcubierre drive (edit | talk | history | protect | delete | links | watch | logs | views), which is sound but unsourced and verbose
• this edit to Rotating black hole (edit | talk | history | protect | delete | links | watch | logs | views), which needs to be rewritten and drastically cut down (to something along the lines of, "frame dragging gives you closed timelike curves and can let you escape from an extremal black hole").

I've given then a welcome-spiel with pointers to useful information, but there will probably be more cleanup to do before the dust settles. --Christopher Thomas (talk) 09:38, 24 July 2010 (UTC)

The text about the star "V 4641" at Rotating black hole is wrong. It appears to be about V4641 Sagittarii, but "V 4641" is an inappropriate name, and in any case it shouldn't have a space. I think it was taken from a document where the ident is used as an abbreviation for the full form (which would need to be specified, because this is a formulaic constructed name (Variable star designation) ), or from some popular science article that didn't know any better. 76.66.193.119 (talk) 05:27, 25 July 2010 (UTC)

QCD question

I was working on nucleon, and there's a technical section in the article ((Nucleon#Models) about ways to approximately solve the Quantum chromodynamics equations to learn about nucleons, including lattice QCD, skyrmion, MIT bag model, chiral bag model, etc. If I'm not mistaken, these apply equally well to all hadrons, not just protons and neutrons. If that's true, I think the section should be cut-and-pasted to hadron. (There are also briefer discussions of this in QCD matter and QCD vacuum and Quantum chromodynamics, but I think hadron should be the main center for this topic.) Can anyone confirm that that's reasonable? I don't know much about this topic. Thanks! --Steve (talk) 18:00, 24 July 2010 (UTC)

I'm not an expert on that either, but the "non-linear SU(2) pion field" part makes me suspect it could be something that only applies to up and down quarks. (On the other hand the Skyrmion article says "baryons".) A. di M. (formerly Army1987) (talk) 18:20, 24 July 2010 (UTC)

Pions (and to a lesser extent other mesons) mediate the residual strong force, which affects all nucleons. Lattice QCD applies to all hadrons (not just baryons or nucleons), and the other models you list should be applicable to other baryons with a bit of tweaking. Finding references for those, of course, will be the time-consuming part (they're there; it'd just require a literature search by someone with access to a particle physics citation database). The "light front holography" approach mentioned above, along with other attempts at using dualities to handle QCD calculations, might bear mentioning as well, though these are relatively new techniques (and so won't have as much of a footprint in the literature for the time being). --Christopher Thomas (talk) 20:32, 24 July 2010 (UTC)

Light front holography

Could any and all look over Light front holography, and preferably help make it a bit clearer to the layman? Many thanks,  Chzz  ►  04:14, 23 July 2010 (UTC)

It's fascinating stuff, albeit not my field. I'll take first pass at making it more accessible (among other things, about half of the lede material should be in a body section, not the lede). The layman-accessible content will be at most a sentence or two, though, be advised (not much more detailed than "this is a mathematical trick that makes the QCD equations easier to solve"). I'll post when I've finished, so that people with more expertise than I have can make sure I didn't accidentally corrupt anything. --Christopher Thomas (talk) 04:23, 23 July 2010 (UTC)

Ok, the lede is now one paragraph and closer to layman-accessible, and I've moved the more detailed introductory material to its own section. The wave equation section could use expansion and discussion, and I'd greatly appreciate it if someone (perhaps Conjecturix (talk · contribs) or yourself?) could look it over for accuracy, in case I introduced errors. --Christopher Thomas (talk) 05:11, 23 July 2010 (UTC)

Many thanks; looks better already.  Chzz  ►  16:50, 25 July 2010 (UTC)

Need help on Nanorobotics

in reverting speculation and promotion. The editor simply does not listen. No any expertise in the topic is required to understand that. Materialscientist (talk) 01:37, 26 July 2010 (UTC)

Logarithm

I'm currently working on logarithm. Two questions (of a non-physicist), any answer is appreciated:

1. Logarithmic timeline seems to suggest that the evolution of the universe is somehow logarithmic (i.e., in the first nanoseconds after big bang happening so much more than in a nanosecond these days). Is there anything substantial to that point of view? I.e., is there any physical quantity which evolved logarithmically?

2. What are the most prominent applications/formulas etc. featuring logarithms in Physics?

Thanks again, Jakob.scholbach (talk) 18:50, 26 July 2010 (UTC)

With regards to the first point, the simplest models of cosmic inflation have the universe's size increasing (and temperature decreasing) exponentially. However, this only covers part of the timeline. In practice, a logarithmic scale is just very handy at showing a large number of very different energy scales in a human-readable chart. It's widely used, but I don't think it reflects any underlying physics.

The more problematic section, from what I can tell, is the one plotting human history and geologic events on a logarithmic scale. It's convenient to draw charts like that, for the reason mentioned above, but you only get evenly-spaced events because we know of many more recent events than distant-past events.

With regards to scientific use, there are quite a few relations that use exponential function. Some of these could be re-expressed in terms of the logarithmic function, though in practice they usually aren't. Exponential functions with complex number arguments show up nearly everywhere, as they're a natural solution to a type of system (linear, time-invariant systems) that are used as approximate representations of a huge number of more complicated systems.

I'm not sure offhand what types of equation or system use logarithms by preference. pH in chemistry is the main example I can think of. As for use outside of equations, log/log and log/linear graphs are widely used when performing curve fitting, as they make certain common types of relation (polynomial and exponential, respectively) look like straight lines on the graph. --Christopher Thomas (talk) 21:33, 26 July 2010 (UTC)

I think there's a bit more to it than that. A logarithmic timeline is the natural way of looking at the evolution of the universe because the timescale of interest is effectively the time for the universe to double in size, rather than the time for it to get, say, 1 metre bigger. The different types of physics in the early universe basically happened on completely different length (and time, and temperature) scales to each other.

Most important formula featuring logarithms: I'd suggest S = k log W (Boltzmann's entropy formula) would have to be pretty high on the list. A lot of equations are generally writen in exponential form, but ones which are normally written in log form include the Tsiolkovsky rocket equation. Djr32 (talk) 21:41, 29 July 2010 (UTC)

Excellent point regarding entropy! I'd forgotten about that, and I agree that it's extremely important.

Regarding timescales of interest, my point is that these aren't fundamentally derived from a logarithmic scale. they're instead derived from various energy scales set by particle physics without any apparent pattern (the masses of the fundamental particles, the various force unification scales, and the various other constants that give things like nuclear and electron binding energies as consequences). A log scale works better than a linear scale for plotting these scales, but if we were to do something crazy like use a factorial scale, that would work about as well too. --Christopher Thomas (talk) 22:01, 29 July 2010 (UTC)

Wikipedia:Articles for deletion/Extended Heim Theory

We're going to need some experts to assess this one! Tim Vickers (talk) 19:09, 29 July 2010 (UTC)