Wikipedia talk:WikiProject Physics/Archive 17

This is the archive "Wikipedia talk:WikiProject Physics/Archive 17". It is for May 2007.

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Archive 17

Electromagnetic stress-energy tensor

Does anyone here know enough about both electromagnetism and relativity to check Electromagnetic stress-energy tensor? Although the article has been changed several times by various people, I have never been satisfied that it is correct. Checking articles on EM is difficult (for me at least) because there are several conflicting sets of conventions in use which affect this topic, it is not just a matter of converting units. JRSpriggs 06:34, 1 May 2007 (UTC)

It doesn't have any strikingly obvious errors, but I just gave it a short look. I can look it over again when I'm not so tired if someone else doesn't get to checking it more thoroughly. Besselfunctions 12:51, 1 May 2007 (UTC)

Energy

An editor has recently begun to split Energy into several articles and general reorganize that article. It would be helpful for additional editors familiar with the subject to collaborate in this task. CMummert · talk 13:54, 1 May 2007 (UTC)

This article is now the subject of a post at WP:ANI involving User:Hallenrm, and it appears to be rapidly changing at the moment. It will be difficult to get involved with so much happening with the article and the people involved with the article. The article even moved as I tried to type a comment on the talk page. Maybe we should just wait for things to settle down. Dr. Submillimeter 14:33, 1 May 2007 (UTC)

BF3 Tube Neutron Detector deletion

Theory, Design and Calibration of a BF3 Tube Neutron Detector has recently been nominated for deletion; as it is becoming painfully obvious that none of us on AfD understand enough particle physics to decide whether this is a worthwhile topic for an article, would anyone who does know enough about the matter to have an opinion take a look at the AfD discussion and contribute accordingly? Many thanks — iridescenti (talk to me!) 20:11, 1 May 2007 (UTC)

Anti-gravity?

There is another article being promoted by the pseudo-scientists, to wit, anti-gravity. Tcisco (talk · contribs) linked to it (through the redirect "gravity control") from History of general relativity, saying "The role of the 1950's gravity control propulsion projects in the history of general relativity.". I removed the link. Get ready for another edit-war and/or AfD. JRSpriggs 09:45, 5 May 2007 (UTC)

(Superquantum) non-locality

There has been a lot of work done over the past few years on super-quantum non-locality, which comes out of work by Sandu Popescu and Daniel Rohrlich showing that the CHSH inequality can be violated to an absolute value of four, in breach of Tsirelson's bound for quantum correlations. There is an article that discusses Nonlocality briefly, but it isn't entirely comprehensive. I was wondering if the project here would object if I rewrote this article with a comprehensive review of non-local boxes, maximal violations of Bell's inequalities, etc. I think it's such a large topic that it merits its own article rather than being spread out over many. The topics I would like to cover would be (ion no particular order):

- brief overview of EPR, Bell's inequalities, and Cirelson's work (mostly linking to the existing articles on the subjects, so only one or two paragraphs)
- superquantum violations of the CHSH inequality, and how they are theoretically achievable
- the various classifications of non-signalling boxes (including local boxes) and what conditions a non-signalling box has to fulfil in terms of joint probability distributions
- links to applications of quantum non-locality (as appropriate) and a brief discussion of usefulness in computation (as per a paper by Linden, Popescu, Short and Winter)

I don't envisage removing any of the general overview of non-locality already in this article, but would combine it into appropriately titled sections, such as a general definition, and some philosophical aspects.

Since this was my undergrad specialism, I would like to be able to write it, but not without checking with you guys what you would like done first! Please get back to me --Fritzpoll 11:55, 6 May 2007 (UTC)

We can ask User:Tsirel himself. As per the usual recommendation he didn't edit "his" article Tsirelson's bound (wouldn't be bad in this case IMHO, the current state of the article is ... err ... suboptimal). But in the field as a whole, he may want to contribute. --Pjacobi 17:34, 7 May 2007 (UTC)

Maybe in the meantime, I can get started and others can chip in with corrections? Provided the idea of including all the above in the article is considered acceptable --Fritzpoll 17:47, 7 May 2007 (UTC)

The key problem is, whether you can manage an encyclopedic treatment. If you envision something more textbook or review-like, you may be better off to start a WikiBook. --Pjacobi 17:55, 7 May 2007 (UTC)

Ok, what I'll do is write out the article as I wanted to write it, and then I'll dump it in my sandbox. I'll come back here and let you know its finished, and it can be decided then whether it is suitably encyclopaedic. I don't intend derivations, particularly, since they won't be especially useful. Mostly a statement and explanation of key ideas - the end result I envision is a more thorough and lengthy article than exists at present --Fritzpoll 20:09, 7 May 2007 (UTC)

Indeed, the current Nonlocality article can muddle the reader. At the very least, various ideas of nonlocality should be disambiguated carefully.

However, I do not want to do it myself. Recently I wrote two articles, Large deviations of Gaussian random functions and Standard probability space; why did I? Since I felt that (a) the topic can interest thousands of students, but (b) maybe I was the only wikipedian able to describe it.

Nonlocality topic satisfies (a) but violates (b); many wikipedians should be able to describe it. I hope that others can do it better than me, namely, more readable for non-experts. I'd better make remarks when needed. And of course, I am ready to answer questions, if any. Boris Tsirelson 12:19, 8 May 2007 (UTC)

That would be great! I will make an attempt to update the page in about two weeks --Fritzpoll 17:44, 14 May 2007 (UTC)

Quantum computer is on FARC

I took a stab at addressing the problems of the quantum computer article (as per the Featured Article Removal Candidate discussion), but since it's not exactly my sub-sub-field of expertise, I'm sure other people will have better ideas of references to add. Anville 15:40, 7 May 2007 (UTC)

New physics-related FAC

..in the making. ;) Now that equipartition theorem has been made into a Featured Article, a few of us have been ensnared by X-ray crystallography, which is the Science Collaboration of the Month. Won't you join in? I promise you, arguing over AfDs cannot bring you the satisfaction of writing a featured article that people will appreciate and learn from. The community of editors is more fun, too! :) Would you really rather dispute with cranky cranks rather than working towards a common goal with Nice People Who Have a Clue? Willow 05:57, 9 May 2007 (UTC)

Vacuum energy

Perhaps I'm wearing my paranoidal hat today, but alarmed by its German pendant nominated for deletion, I've re-checked Vacuum energy and would consider it lacking. It doesn't give a coherent view along the main topics butoutlines some rather anecdotical connections.

Amazingly it doesn't seem to be User:Reddi's fault in this case. Also past versions, which sometimes saw minor correction by physics regulares, give the same impression.

Is the problem between my ears or in the article?

Pjacobi 16:14, 11 May 2007 (UTC)

And some trouble at Zero-point field

which was and most likely should be again a redirect to vacuum state. Now it has become a strange mixture of history of QM, Haisch-cruft and worse. See tal page. --Pjacobi 16:40, 16 May 2007 (UTC)

POLICY DEBATE: Use of source code, mathematical examples and other examples in articles

I have opened a debate on the use of examples in Wikipedia articles (mainly focusing on computer source code and mathematical proofs, equations, etc.). It seems to me that many examples currently in Wikipedia violate Wikipedia policy, so I believe we need to either clarify or change the situation. Depending on the result of the discussion, this may result in a number of examples being summarily removed from articles!

Please reply there, not here, if you wish to contribute.—greenrd 11:12, 18 May 2007 (UTC)

Mathematical physics

I know this probably not the right place to post this but please be patient with me. I am just here to let everyone know that Mathematical Physics ;) is the current Math collaboration of the month, and we can use all the help we can get! Thanks--Cronholm144 05:53, 21 May 2007 (UTC)

Guard against teslacruft

Tesla-fanatic User:Reddi has been inserting more Tesla-nonsense into Electric power transmission. Please help keep Wikipedia free of such nonsense. Thanks. --ScienceApologist 17:46, 21 May 2007 (UTC)

Is there a problem with the latest version from Reddi? If there is, can you explain here what is false or POV about it? I'm hesistant to enter this fight unless I really think there is something to fight about. Josh Thompson 17:09, 26 May 2007 (UTC)

Confused with redirect and article

Hi everyone in WikiProject Physics. I've juct come across this redirect: Field Lines linked to Force field (physics). The problem is there's a particular article named Field line. So should we merge the two articles (Force field and field line) or change the target of the redirect? AW 15:15, 26 May 2007 (UTC)

I've changed the redirect, as I believe that doing so is the best option. The Field line article isn't of the highest quality, however, so feel free to improve it. —Constantine 02:21, 27 May 2007 (UTC)

Talk:Gamma spectroscopy

I'm thinking about creating some new spectra to add to the Gamma spectroscopy article, since I was responsible for removing the old image of a spectrum from an HPGe detector. If anyone has any comments on what sorts of spectra would be best, please let me know on the talk page for the article. —Constantine 02:21, 27 May 2007 (UTC)

Relativity Theory

You would think that an article with this title was about physics, would you not? Think again. JRSpriggs 06:46, 29 May 2007 (UTC)

Fixed. --ScienceApologist 07:17, 29 May 2007 (UTC)

Thank you. I think you covered all the bases. JRSpriggs 09:46, 29 May 2007 (UTC)

Enormousdude

This user, Enormousdude (talk · contribs), keeps making strange changes to physics-related articles. He appears to have a poor grasp of English and to be attempting to write at a higher level than is appropriate here. I've just reverted him on Force, although he may have had some improvements. Can anyone help here? The way, the truth, and the light 21:19, 30 May 2007 (UTC)

That's a strange edit by Enormousdude :) Virtual particles are just an artefact of the perturbative expansion. Even if you sum all the contributions to all orders you don't necessarily get the exact force, because of non-perturbative effects that are zero at all orders in perturbation theory. Count Iblis 22:04, 30 May 2007 (UTC)