Wikipedia talk:WikiProject Physics/Archive November 2023

Wikipedia:Articles for deletion/Introduction to M-theory (2nd nomination)

This discussion may be of interest to the community here. XOR'easter (talk) 18:21, 6 November 2023 (UTC)

Draft:Fractional Chern Insulator

The article Draft:Fractional Chern Insulator recently failed a WP:AfC, I think because it was reviewed by people who do not know the physics. Perhaps one or two of you would like to help the article, and also check whether it is a duplicate. It is a bit outside my expertise. Ldm1954 (talk) 13:43, 5 November 2023 (UTC)

It is certainly notable, however I think it is such a technical topic that it does not seem to have gotten into a digestible review. Topics like Topological insulator and quantum spin Hall effect still suffer from being written without very little interest to explain basic stuff. I think we need some extra effort from the topological quantum community.--ReyHahn (talk) 09:32, 6 November 2023 (UTC)

I've accepted it with a bit of copyedit. The sources, which now have arxiv copies so are readable, have some with good review of the field introductions. Trying to see if I can provide some context in the lead at an elementary level, but may not be able to. StarryGrandma (talk) 00:17, 9 November 2023 (UTC)

Requested move at Talk:Tractive force#Requested move 1 November 2023

There is a requested move discussion at Talk:Tractive force#Requested move 1 November 2023 that may be of interest to members of this WikiProject. Polyamorph (talk) 18:43, 15 November 2023 (UTC)

Proposal to move Stationary-action principle to "Principle of least action"

The principle of least action is described on a page called "Stationary-action principle". Historically the name was "principle of least action" or "Hamilton's principle"; Feynman adopted "least action" in 1948, acknowledging that the action is not always minimal. I found only one reference that mentioned "stationary action principle".

The page was originally "Principle of least action", but it was renamed with the edit comment:

1. The old name is logically/mathematically flawed: the principle does not require the action functional to be minimal on trajectories.
2. The new and the old name are used equally in modern literature.
3. The new name properly depicts the underlying principle.

The first and third reasons are the same reason; not one that is important for readers to recognize the topic. The second reason is unreferenced.

My reading of WP:TITLE:

• Recognizability: least action wins.
• Naturalness: people will search for least action
• Precision: tie, no ambiguity
• Concision: tie: similar length
• Consistency: tie? xx principle vs principle of XX?

Since the move was made once to this name I think I should get confirmation before action. Johnjbarton (talk) 17:55, 14 November 2023 (UTC)

• I agree with you that per notability "principle of least action" is more widely used (it is what appears in the Goldstein). Maybe we should be careful with Hamilton's principle (is it the same?) should that be merged in?--ReyHahn (talk) 18:08, 14 November 2023 (UTC)
• I agree with the above, but I am not sure about merging in Hamilton's principle. Bduke (talk) 22:21, 14 November 2023 (UTC)

Comment: such discussions should take place in the corresponding article's talk page; there's even a special template for proposing a change in page title, see details at WP:RSPM. Then you can ping it here about the discussion there. But now that it's underway here, you should at least ping it there. That's the only way past editors will get to notice it. fgnievinski (talk) 00:52, 15 November 2023 (UTC)

done, thanks. Johnjbarton (talk) 03:28, 15 November 2023 (UTC)

OR Now that I have found more refs, including Goldstein's 3rd ed which discusses their decision to adopt new names: I think our readers would be bette served with a page called Action principles that gave an overview of the concepts and advantages, comparing the different principles, summarized the issues, discussed the naming, etc.

I will hold off on any move, and develop this idea first. Johnjbarton (talk) 05:08, 15 November 2023 (UTC)

It should have a proper WP:RM discussion before moving in any case really. -Kj cheetham (talk) 09:35, 15 November 2023 (UTC)

I think we should avoid WP:RMs when the details are not clear or when there are no opposing users. A preliminary survey is always useful.--ReyHahn (talk) 10:47, 15 November 2023 (UTC)

It not being clear is all the more reason for a WP:RM once there is a proposal to move, before moving. Plus the fact it's been moved before and there's need to discuss it indicates it is a WP:PCM. I do agree a preliminary survey is certainly useful though. -Kj cheetham (talk) 10:54, 15 November 2023 (UTC)

• I think 1948 is long enough ago that terminology from then shouldn't be binding. We say muon instead of mu-meson and capacitor instead of condenser; in 1948, a common meaning of computer was still "the wife of a scientist, paid half salary to operate a Marchant calculator". XOR'easter (talk) 21:49, 15 November 2023 (UTC)

This is universally known as the principle of least action. The caveats can be discussed as normal. Headbomb {t · c · p · b} 22:56, 15 November 2023 (UTC)

Widely, but not universally [1][2][3][4]. I am not sure the choice of title matters so much. XOR'easter (talk) 02:54, 16 November 2023 (UTC)

All these also mention least action alongside stationary action. Headbomb {t · c · p · b} 03:03, 16 November 2023 (UTC)

• 2c: Stationary action is clearly the physically correct name, for reasons mentioned above. While more sources do use least action, most of them also mention in concurrence that this is a misnomer, that maximal action or local minima occur in different cases, etc. I would support a proposed move (this isn't a case like Liancourt Rocks where everyone has a different idea of what the "real" name is, we all agree on what is the most accurate descriptor). That said, also as mentioned above, all this should be in a proper WP:RM. Fermiboson (talk) 09:43, 16 November 2023 (UTC)

As users are requesting, @Johnjbarton: please open an WP:RM I suggest that you propose the three options: (a) stationary action principle (b) least-action principle (c) action principle.--ReyHahn (talk) 13:33, 16 November 2023 (UTC)

Just an interesting physics tidbit I have stumbled upon: it appears that the name "principle of stationary action" derives from Julian Schwinger's work. Both Feynman and Schwinger developed quantum action principles; both of them renamed the classical Hamiliton's principle! Feynman went with "principle of least action" and the more button-down, mathematically precise Schwinger chose "principle of stationary action". (I have refs for Feynman renaming; it's possible that "stationary action principle" precedes Schwinger but a Nobel laureate's word choice must be significant). Milton, K.A. (2015). Review of Classical Action Principles. In: Schwinger's Quantum Action Principle. SpringerBriefs in Physics. Springer, Cham. https://doi.org/10.1007/978-3-319-20128-3_2 Johnjbarton (talk) 02:38, 19 November 2023 (UTC)

And while we’re on the topic of essay-like articles…

Car speed and energy consumption. Reads like a student assignment to me. Opinions? I’m leaning towards AfD. Fermiboson (talk) 18:50, 17 November 2023 (UTC)

It started as a translation of the Dutch article dating from 2019 by the same editor. Translation should have been indicated. StarryGrandma (talk) 19:32, 17 November 2023 (UTC)

Redirect to Fuel economy in automobiles.--ReyHahn (talk) 19:38, 17 November 2023 (UTC)

I'd support a nomination for merging into Energy-efficient driving. fgnievinski (talk) 03:01, 18 November 2023 (UTC)

Given that the content is mostly a high school level calculation of F = kv^2 etc formulae, I'm not sure what value there is to a merge. Fermiboson (talk) 03:52, 18 November 2023 (UTC)

Strong Delete as it is very wrong. It is true that driving faster can be less efficient, but the science in the Wikipedia page is incorrect. A standard source on this topic is DOI:10.1016/j.triboint.2011.11.022, which does the analysis right, and is the "Go To" paper that everyone uses. You can see the losses on p233, the article is open source. The correct number for air drag is ~ 5%, whereas Car speed and energy consumption claims it dominates. Ldm1954 (talk) 05:52, 18 November 2023 (UTC)

Dear @Ldm1954 , Thank you for pointing out this discrepancy, that does not touch the argument of quadratic velocity dependence. Holmberg et al. agree on that too. Thank you, Hansmuller (talk) 13:11, 19 November 2023 (UTC)

Sorry I would like to understand the logic behind "delete". The excellent reference makes a compelling case that this topic is notable. So isn't the proper course of action to correct the content? Neither of the other articles mentioned here list this reference so aren't they also suspect? Johnjbarton (talk) 15:35, 18 November 2023 (UTC)

The problem as far as I can tell is that the stuff of industrial relevancy is already in the various articles mentioned above, like Fuel economy in automobiles and Energy-efficient driving. The original article is essentially a high school physics exercise and has little standalone value. Fermiboson (talk) 16:21, 18 November 2023 (UTC)

I think we have high school physics readers who would appreciate an accurate article at their level. Johnjbarton (talk) 16:24, 18 November 2023 (UTC)

Well... we don't make articles on uniform cylinders rolling down fixed wedges. I suppose one could make a case for something like Introduction to vehicle fuel efficiency, but that would definitely not be anywhere close to this article in style or content. See also WP:NOTTEXTBOOK: The purpose of Wikipedia is to summarize accepted knowledge, not to teach subject matter. Articles should not read like textbooks, with leading questions and systematic problem solutions as examples. Fermiboson (talk) 16:33, 18 November 2023 (UTC)

Adding to what has been said above, the article is very, very inaccurate. The article I cited is a review that was encouraged by both the DOE & the EU. The senior author Ali Erdemir is one of the better known tribologists. I trust him, and I trust that work -- I have worked in nanotribology so this is a "pseudo-expert opinion". Ldm1954 (talk) 17:14, 18 November 2023 (UTC)

Overkill, 1739 citations to that article in Google Scholar, https://scholar.google.com/scholar?oi=bibs&hl=en&cites=18027991641630258539 Ldm1954 (talk) 17:17, 18 November 2023 (UTC)

Dear @Ldm1954, Erdemir agrees on the overall theory and quadratic speed dependence, p. 223. The Holmberg get al. article does not at all consider a range of high speeds, the topic of the Wikipedia article from the source MacKay, Sustainable energy without the hot air, a UK Govt. report. Thank you, Hansmuller (talk) 13:16, 19 November 2023 (UTC)

Fermiboson AfD is probably the way forward. -Kj cheetham (talk) 10:53, 18 November 2023 (UTC)

Done. Fermiboson (talk) 13:17, 18 November 2023 (UTC)

• @Fermiboson @Ldm195 Thanks for your interest and the important references. They agree with the discussed Wikipedia article which is based on the MacKay UK goverment advice Sustainable energy without the hot air, 2008.
  • K. Holmberg et al. / Global energy consumption due to friction in passenger cars / Tribology International 47 (2012) 221–231 agree with this Wikipedia article, they state on page 223:

"The external air drag is the air resistance of the car when it moves on the road. It is proportional to the square of the driving speed and directly related to the size and shape of the vehicle, usually expressed as a multiplication of the drag coefficient by the projected front area [34,35]. In this study, 60 km/h is assumed as an average driving speed for all cars globally in urban, highway, and any other kind of driving.". Holmberg et al. do not further address the effect of speed.

• • Holmberg et al., Global energy consumption due to friction in passenger cars, transportation and industry, STLE Annual Meeting, Detroit, USA, 5-9.5.2013, echo the MacKay argument for a quadratic dependence on speed on their pages 8 and 9, with similar graphs we can use as reference in the article, and refine the argument.

Thank you, Hansmuller (talk) 12:54, 19 November 2023 (UTC)

I responded to your comments on the AfD page, perhaps any future science discussion should only be here.

@Hansmuller nobody has disagreed with the quadratic dependence of air drag on velocity. However, there are two issues:

• The tone, which is what @Fermiboson first queried
• The focus on the 5% contributions to energy loss and ignoring the 95% terms which I object to. IMHO this is a case for Blow it up and start over. If you or someone else volunteers to rewrite then perhaps put the AfD on hold, otherwise not. Ldm1954 (talk) 14:03, 19 November 2023 (UTC)

I don't agree with the claim that this article is incorrect on science.

The excellent Holmberg et al. article provides evidence that 5% of the energy loss is air drag. However, that 5% is also 100% of the energy loss that a driver of an existing passenger car can affect by daily behavior. No strategy discussed in the Holmberg article affects existing cars; their strategies are all things for governments or technology companies.

I think the article should discuss the reality that personal behavior affects only a small part of the energy loss. That is an important fact that alters the perspective of the discussion. Johnjbarton (talk) 22:38, 19 November 2023 (UTC)

Good article reassessment for International System of Units

International System of Units has been nominated for a good article reassessment. If you are interested in the discussion, please participate by adding your comments to the reassessment page. If concerns are not addressed during the review period, the good article status may be removed from the article. ~~ AirshipJungleman29 (talk) 22:30, 20 November 2023 (UTC)

Variational methods in general relativity

Is this article necessary/notable: Variational methods in general relativity. As it does not add anything is it safe to just transform it into a redirect to Einstein–Hilbert action? ReyHahn (talk) 12:46, 21 November 2023 (UTC)

Do it.

The name "Einstein-Hilbert action" is rather obscure compared to "Variational methods in general relativity", so swapping the names might make sense. Johnjbarton (talk) 16:33, 21 November 2023 (UTC)

I strongly disagree. Einstein-Hilbert action is only one of many types of action in GR. In general, there are several forms of the action in which the integrand is of the form f(R) sqrt(-g). f(R)=R is not the only functional form that produces Einstein field equations, and the difference is of significance in quantum gravity. The subject is undoubtedly notable and distinct from each other. Fermiboson (talk) 00:12, 22 November 2023 (UTC)

Do not redirect, as above. Xxanthippe (talk) 00:32, 22 November 2023 (UTC).

The first line of Einstein-Hilbert action says "The Einstein–Hilbert action in general relativity is the action that yields the Einstein field equations through the stationary-action principle". So "the action" according to this "authority" ;-)

The General relativity page does not discuss any actions, how important can they be? What articles discuss those other actions in GR? How would a reader find them? How would a reader interested in GR discover the Einstein-Hilbert action?

To me this is a pervasive problem in Wikipedia Physics: a large pile of topics interrelated with a maze of wikilinks but few overviews.

(I'm not blaming anyone here, but doing nothing in this case is the least good outcome IMO). Johnjbarton (talk) 01:43, 22 November 2023 (UTC)

I entirely agree that it would be a good idea to have those articles, and I recently talked with someone with relevant expertise who is working on the coverage. It's a highly advanced nche topic so our coverage is necessarily spotty. Unfortunately, I don't know if I can help much on this one as I'm just a lowly undergrad :) Fermiboson (talk) Fermiboson (talk) 08:35, 22 November 2023 (UTC)

Physical meaning of the Stoney Mass - Potential conflict of interest

• Talk:Stoney units#Physical meaning of the Stoney Mass - Potential conflict of interest

This is a COI edit request from User:AndrewWutke. Looking for a neutral subject expert to review.  Spintendo  04:00, 29 November 2023 (UTC)

Spintendo, I have removed the edit request here - it is appropriate for an edit request about a single page to be at that page. Nothing wrong with posting here to get opinions, but we should not be splitting discussion across multiple pages. Primefac (talk) 07:24, 29 November 2023 (UTC)

@Quondum: Read the reference ( https://iopscience.iop.org/article/10.1088/2399-6528/ad0090 ) for this. It is right up your alley. JRSpriggs (talk) 11:31, 29 November 2023 (UTC)

Comparison of chemistry and physics

Does Comparison of chemistry and physics work as an article? It reads more like an essay to me. XOR'easter (talk) 03:04, 16 November 2023 (UTC)

It seems OK to me. At least there are far worse articles!! Like a large proportion of articles, it just needs a bit of work. Bduke (talk) 04:43, 16 November 2023 (UTC)

It should be noted that this and other physics articles are currently the targets of a student editing course. Xxanthippe (talk) 05:32, 16 November 2023 (UTC).

Seems like an essay to me more than a legit topic. Sure one can compare fields, but like... why these two? Why not physics and sociology? Or chemistry and finance? Headbomb {t · c · p · b} 09:48, 16 November 2023 (UTC)

Looks like an essay to me too. Largely harmless and probably quite useful for some readers if they can find it (it's an orphan right now). The problem is that it isn't an article about comparison of chemistry and physics, it is such a comparison. Normally the articles here are about the subject named in the title: Essay not an essay, it is a description of the written form, history of the essay, and so on. Debate is not a debate. Is comparing chemistry and physics a notable thing to do, with a history to discuss and sources to cite? Maybe I'm being a stickler since few readers will be surprised or disappointed by the current contents, and there exist dozens of other "Comparison of ..." articles. Can it be renamed so it belongs in an encyclopedia? If not, I suggest abbreviating the contents and merging what's appropriate into Physics#Relation to other fields and Chemistry#Practice or both. –MadeOfAtoms (talk) 10:29, 16 November 2023 (UTC)

It might find a better placed in the Simple English Wikipedia. Xxanthippe (talk) 10:43, 16 November 2023 (UTC).

Agree that it is an essay. One may be able to say something about comparison of chemistry and physics in popular perception, but the article title is bad. Fermiboson (talk) 20:52, 16 November 2023 (UTC)

It seems to not, in itself, be an encyclopedic topic: it is not something that might be studied in a discipline (other than career guidance?), per say. Definitely in the 'essay' category. —Quondum 16:55, 29 November 2023 (UTC)

Maybe an article about "relationship between chemistry and physics" would be more adequate in the spirit of Relationship between mathematics and physics.--ReyHahn (talk) 11:33, 16 November 2023 (UTC)

As far as I can tell no reference in this article actually compares chemistry to physics. So the real issue with the article is a complete lack of verifiable references.

As a chemist who worked as a physicist and an engineer, the sentence "Physicists are also employed outside of science, for example in finance, because of their training in modeling complex systems." is clearly physics propaganda from the Institute of physics, not a matter of "comparison". ;-) (The truth of this matter is that too many physicist are trained in comparison to the number of physics jobs). Johnjbarton (talk) 15:26, 16 November 2023 (UTC)