Wikipedia talk:WikiProject Physics/Archive September 2014

Fringe cosmology
Some expert commentary would be welcome. Wikipedia:Articles for deletion/Cosmological General Relativity.

jps (talk) 11:33, 1 September 2014 (UTC)

Source in Ruze's Equation
An unregistered editor raised a question concerning this article. It seems that there is another source about its application to phased arrays. Perhaps someone here can consider it. Anon 126  (notify me of responses! / talk / contribs) 04:14, 7 September 2014 (UTC)

Draft:Spectral line ratios
Dear physics experts: This draft is waiting for a review at AfC. Is this a notable subject, are the references appropriate, and is the draft ready for mainspace? &mdash;Anne Delong (talk) 14:22, 4 September 2014 (UTC)
 * It's in mainspace now - thanks!&mdash;Anne Delong (talk) 22:29, 9 September 2014 (UTC)

Wikipedia talk:Articles for creation/aCORN Experiment
Dear physics experts: Here's an old abandoned AfC submission. Is this a notable topic, or should the page be deleted as a stale draft? &mdash;Anne Delong (talk) 23:14, 8 September 2014 (UTC)
 * Neither I nor my two physicist friends have heard of the project, and I have only found one journal article pertaining to it. If the science really is groundbreaking it's a case of WP:TOOSOON, but my guess is that it's just another way for scientists to more accurately measure things. Primefac (talk) 10:09, 9 September 2014 (UTC)
 * Thanks for taking time to check this out, Primefac. It's been deleted now, but can always be "refunded" if it suddenly becomes of interest at a later date.  &mdash;Anne Delong (talk) 22:31, 9 September 2014 (UTC)

Observable universe size could use expert attention
There's a question of possible off-by-one errors that myself and at least one other editor have been grappling with over at Observable Universe, regarding "epoch of photon decoupling" / "redshift of photon decoupling" and how to interpret the z* line in the WMAP nine-year data paper. If someone with some astrophysics background could give that a quick verification, I'd be much appreciative. Thanks. 0x0077BE [talk/contrib] 20:24, 11 September 2014 (UTC)

Mixed-up redirects for the strong interaction?
Why is it that → Strong interaction but  → Nuclear force? -- Red rose64 (talk) 21:55, 9 September 2014 (UTC)
 * should redirect to Nuclear force, as the strong nuclear force is the residual force among nuclear particles ultimately resulting from the strong interaction. --Mark viking (talk) 22:17, 9 September 2014 (UTC)
 * No other comments after more than a week, so . -- Red rose64 (talk) 07:46, 18 September 2014 (UTC)

Neil deGrasse Tyson - Request for Comment: WP:WEIGHT/WP:UNDUE
Editors of this project are invited to participate in the following RfC. A Quest For Knowledge (talk) 00:54, 23 September 2014 (UTC)
 * Replied. Gryllida (talk) 03:40, 23 September 2014 (UTC)

Assistance requested for improving Lift(Force)
Over at the Lift_(force) page we (the active editors) seem to have come to an impasse over inclusion of the following sentence describing the lift on an airfoil:


 * "The resulting force upwards is equal to the time rate of change of momentum of the air deflected downwards."

Much discussion has ensued; one side wants to include it (there are four reliable sources that support the assertion) and the other side claims it is untrue (citing sources that don't exactly say it's false, but provide equations that can be interpreted to say it is false.) Much more detail is at the Talk page. I'd like to see some more opinions and see if we can come to a consensus about including or excluding that sentence. Thanks. Mr. Swordfish (talk) 12:42, 22 September 2014 (UTC)
 * Replied. Gryllida (talk) 03:45, 23 September 2014 (UTC)

Conflict at Electromagnet
There is a conflict going on at Electromagnet over the use of the term "ferromagnetic". Fresh opinions would be welcome, see Talk:Electromagnet. -- Chetvorno TALK 08:41, 16 September 2014 (UTC)
 * I wouldn't say it's a conflict. The two sides agree surprisingly well.  I've started participating in the discussion. Gryllida (talk) 11:38, 23 September 2014 (UTC)

""
The usage of is under discussion, see talk:Solar Physics (journal) -- 65.94.171.225 (talk) 08:15, 24 September 2014 (UTC)

article on 'Heat death of the universe' not of high importance
I think that the Wikipedia article Heat death of the universe is not of high importance, though it is tagged as of high importance. The future of the universe may well be of importance, but the idea of its heat death is of only historical interest. There are so many factors of the future of the universe that the nineteenth century idea of its heat death is not of much interest or importance. Some experts think even that the topic itself is meaningless. I think the tag "high importance" should be downgraded to some much lower level, perhaps "low importance".Chjoaygame (talk) 00:37, 16 September 2014 (UTC)Chjoaygame (talk) 02:47, 16 September 2014 (UTC)
 * Added wikilink to this section title for easier navigation. Gryllida (talk) 02:25, 16 September 2014 (UTC)
 * Headbomb — why? (page revision at that time). Gryllida (talk) 03:35, 16 September 2014 (UTC)
 * The ultimate fate of the universe is a matter of very high importance to physics (and science), and is something that exemplifies the 2nd law of thermodynamics like nothing else could. The idea that this compares in encyclopedic importance to things like acoustic ohm or natterer compressor is plain ridiculous. No one in the world save maybe a handful of people even heard of what a natterer compressor even is. The heat death of the universe is something people could have encountered in high school science and popular science shows, and will usually also be tackled by any intro to astronomy/astrophysics classes. Headbomb {talk / contribs / physics / books} 00:33, 18 September 2014 (UTC)
 * If it were rated mid-importance, it would have Periodic table, Nuclear fusion, Kilometre and Pendulum for company; while among the articles rated high importance are Gravity Probe B, Fata Morgana (mirage) and Czochralski process. If all the physics articles had the rating they deserved, it's anybody's guess whether Heat death of the universe would end up in high- or mid-importance. But definitely not low. RockMagnetist (talk) 05:05, 18 September 2014 (UTC)
 * Huh? Gravity Probe B and Czochralski process have mid-importance ratings. (And no that is not a recent change. Fata Morgana (mirage) has (and always has had) a low importance rating.
 * On a more constructive note, if you encounter importance ratings that are obviously off, just correct them.TR 08:52, 18 September 2014 (UTC)
 * Oops! I was looking at lists of articles like this instead of directly at the article talk page. I must have mixed the lists up. Anyway, I agree that "just correct them" is the best advice. It's probably not worth taking to a project-wide discussion. RockMagnetist (talk) 14:18, 18 September 2014 (UTC)
 * Headbomb: I think you're misinterpreting "importance" scale here. Poorly written articles get higher importance scale, not those whose topic has high scolarly value.  The assessment is aimed to help prioritising work within a WikiProject. Gryllida (talk) 03:48, 23 September 2014 (UTC) I actually read the quality scale documentation now that I've noticed that there are two scales, a quality scale and an importance scale.  That's an ...interesting facet of prioriting work.  I don't have an opinion on it: set it to what you like.  (I heard of it as an undergrad without specialising in the topic, so I'd personally leave it as is.  I have better things to do than re-assess articles assessed in good faith.  Little changes if we're slightly inconsistent here sometimes.) Gryllida (talk) 03:59, 23 September 2014 (UTC)

If anyone's doing much rating or re-rating, then I recommend Kephir's script at User:Kephir/gadgets/rater. If you've not installed user scripts before, then you can see how to install it in this diff on my common.js page. Just add the exact line and save the page (and, depending on your browser, sometimes reload it to activate it). WhatamIdoing (talk) 05:53, 23 September 2014 (UTC)
 * Thanks for the pointer to the script! I am finding it helpful and it saves a good bit of typing. --Mark viking (talk) 17:49, 24 September 2014 (UTC)

Neutron diffraction
At Matter wave, an editor has stated that "neutron diffraction is nowadays commonly studied as a momentum transfer process" and added a long string of citations. I was not aware that diffraction ever transferred momentum (if so, what receives the momentum? Momentum is a vector: what net force causes the neutron to change course?). Can somebody knowledgeable clarify this? &mdash; Cheers, Steelpillow (Talk) 12:12, 24 September 2014 (UTC)


 * Thank you for this comment. An explicit reference on this is  From paragraph 1, here is a quote: "[In this present article, t]he scattering event is consistently seen as a momentum transfer process. This view is commonly adopted for the neutron case[Frontiers of Neutron Scattering (1999), edited by A. Furrer, World Scientific, Singapore, ISBN 981-02-4069-4], but it is less explored when discussing scattering of photons." The treatment given in the Furrer reference is more or less the same as that given in Squires, G.L. (1978/2012). Introduction to the Theory of Thermal Neutron Scattering, third edition, Cambridge University Press, Cambridge UK, ISBN 978-110-764406-9. This kind of process is described in  by the term "matter wave", where, as in the foregoing references, the mathematical treatment is in terms of the wave vector.Chjoaygame (talk) 15:47, 24 September 2014 (UTC)
 * I was asking about neutron diffraction, not neutron scattering. I was taught that they are very different things, the one best treated as wave interference and the other as a particle collision. The article on Momentum transfer says that momentum is also important in Bragg diffraction but the article on Bragg diffraction doesn't mention momentum anywhere, while it does give the familiar wave interference model. Hence my request for clarification. &mdash; Cheers, Steelpillow (Talk) 16:24, 24 September 2014 (UTC)
 * [Update] OK, I have now found a relevant explanation. I have other concerns with Chjoaygame's treatment, but we can keep those for the article talk page. Sorry to bother you here. &mdash; Cheers, Steelpillow (Talk) 17:17, 24 September 2014 (UTC)


 * Obviously, the force is exerted by the diffraction grating or whatever plays that role (e.g. planes of atoms in a crystal). JRSpriggs (talk) 01:24, 25 September 2014 (UTC)

Cyclical categorization

 * Category:Condensed phase is contained in Category:Condensed matter physics
 * Category:Condensed matter physics is contained in Category:Condensed phase
 * Is it better to merge both categories or to decide which category is "child-category" and which is the "parent-category"? Kazkaskazkasako (talk) 20:40, 18 September 2014 (UTC)


 * Merge Category:Condensed phase into Category:Condensed matter physics. Condensed phase has no other contents besides two other subcategories. Whereas Condensed matter physics is very well populated. JRSpriggs (talk) 04:08, 19 September 2014 (UTC)


 * Agreed with JRSpriggs. Condensed matter physics is a gigantic topic which includes many other topics (e.g. solid state physics) and phenomena, so a merge is appropriate. M&and;Ŝc2ħεИτlk 22:57, 19 September 2014 (UTC)


 * The two subcatogories moved from "Category:Condensed phase" to "Category:Condensed matter physics", only empty category ("Category:Condensed matter physics") remains waiting for deletion (Categories for discussion/Log/2014 September 26) Kazkaskazkasako (talk) 10:17, 26 September 2014 (UTC)

Wikipedia talk:Articles for creation/EIPM effect
Dear physics experts: This old AfC draft was never submitted and now its about to be deleted as stale. Is this a notable topic, and should the draft be kept and improved instead? &mdash;Anne Delong (talk) 21:30, 26 September 2014 (UTC)
 * The topic appears to be verifiable and I think notable enough for its own article (hard to know whare to put it otherwise). But I'd suggest that "EIPM effect" is too ambiguous a title and that the article should be created as Electron-refractive effect. I have edited it with this in mind, and also removed a little uncited speculation. &mdash; Cheers, Steelpillow (Talk) 09:58, 27 September 2014 (UTC)
 * Thanks, Steelpillow; it's in mainspace now. &mdash;Anne Delong (talk) 11:48, 27 September 2014 (UTC)