Wikipedia talk:WikiProject Physics/Archive May 2023

Second law of thermodynamics

I suppose I shouldn't be surprised that an article like Second law of thermodynamics is kind of crufty, but it could use attention. XOR'easter (talk) 17:31, 7 May 2023 (UTC)

It's a long article. What is the nature of your concerns (or some of them)? Xxanthippe (talk) 23:11, 7 May 2023 (UTC).

It just seems in poor repair overall. On a first reading, I found a misplaced tag, some external-link spam, weird linking and confusing pop science with the real thing... I expect that it's accumulated some oddities over the years. XOR'easter (talk) 02:22, 8 May 2023 (UTC)

Edit and page creation proposals: DESY lab, DESY accelerator and DORIS accelerator

In an effort to update and de-clutter the main article about the German accelerator lab DESY I have made many edit proposals to existing articles connected to the lab and its research facilities, most of which have been implemented (thanks to everybody who was involved for their feedback, support and guidance!).

Here are now two suggestions on my Sandbox page for articles to be created about the last two DESY accelerators that don't have their own pages yet:

User:Redactrice at DESY/DESY (particle accelerator)

I've also created a Sandbox page with suggested edits to the main DESY article to update it as described above:

User:Redactrice at DESY/DESY revised

I have declared my conflict of interest on my user page and I hope I have followed all the rules of good wiki practice.

I'd be very grateful for your help and feedback. Thanks in advance! Redactrice at DESY (talk) 09:29, 11 May 2023 (UTC)

• @Redactrice at DESY: Please place this edit request (and the associated request edit template) on the talk page of the article you would like to edit. Thanks! Z1720 (talk) 13:35, 12 May 2023 (UTC)

  @Z1720 I had already placed a note / new topic on the DESY talk page at the same time that I posted it here, albeit without the edit request template. I'm unsure whether to add it or not after @Quondum's comment...?!

  As the other articles don't exist yet there's no talk page to add a request to. However, they are all related to DESY, so I grouped them all under one topic.

  By the way, the new articles are based on the content featured in the current DESY article. Do I need to make a request to import content or something similar? It is only a partial import after all.

  Newbie learning the ropes, sorry! Redactrice at DESY (talk) 17:12, 12 May 2023 (UTC)

• If you want to create a new article, you can write the draft and submit it to WP:AFC if the topic is notable. Since the above does not ask to change anything in an existing article, the request edit template is probably not appropriate here. Z1720 (talk) 17:16, 12 May 2023 (UTC)

• Actually, I don't think that the {{request edit}} template is appropriate at all in this instance. However, the request as made here, unless someone identifies a better approach, seems to be reasonable. Maybe someone here will have some time to look at this. —Quondum 15:11, 12 May 2023 (UTC)

I suggest that all further discussion on this should be at Talk:DESY § Edit and page creation proposals: DESY lab, DESY accelerator and DORIS accelerator; interested editors can navigate there using this link. —Quondum 19:54, 12 May 2023 (UTC)

Comments requested on Electron diffraction

I have tried to reconstruct this page so it is a three-way balance between being moderately understandable, rigorous and also inclusive. Not so easy, as simple ideas such as Bragg's Law, de Broglie wavelength are not enough. Plus balance between the competitors such as TED/LEED/RHEED matters.

I would be interested in comments...

N.B., at some stage a proper page on dynamical electron diffraction is needed. Ldm1954 (talk) 12:42, 27 April 2023 (UTC)

Nice work!

I would like to see a bit more on fresnel (aperture) diffraction, calling out the different physics from Bragg diffraction. The fresnel examples are important historically and for foundation physics. We should be able to clarify why the Bragg cases have more practical value in addition to enumerating them. I will look into some specific suggestions. Johnjbarton (talk) 21:16, 12 May 2023 (UTC)

I am guessing that you mean Fraunhofer, not Bragg diffraction. It would be appropriate to cross-reference to the Fresnel diffraction and Fraunhofer diffraction pages. Perhaps in the description, and maybe a second time in the geometric considerations. Or were you thinking of something else? Ldm1954 (talk) 22:04, 12 May 2023 (UTC)

Something like that yes. I would like Matter_wave to work better with this page. When I come to ED from MW I feel a "What Just Happened", rather than "ok got it". To be sure MW is in worse shape.

Also https://pubs.acs.org/doi/10.1021/acs.chemrev.1c00879#

Has some good material on dynamics and history.

I can make concrete suggestions after the weekend. Johnjbarton (talk) 22:40, 12 May 2023 (UTC)

I would definitely not recommend that paper, for many reasons that I won't list here. Ldm1954 (talk) 22:51, 12 May 2023 (UTC)

I will also add that at a higher level than in the article, both Fresnel and Fraunhofer diffraction are involved. Some methods of solving for dynamical diffraction involve Green's function propogators, which can be simplified to Fresnel -- see multislice. Others use Bloch waves so are Fraunhofer; some (channeling) use both! I did a little clarification, but it is tricky.

Hard core electron diffraction always starts from a relativistically-corrected Schroedinger equation, as the page says. I think aspects of this need to be added to the matter wave page. Ldm1954 (talk) 17:00, 13 May 2023 (UTC)

I would like propose some suggestions to make the intro less steep. I will add an topic to Talk:Electron diffraction and see how that works... Johnjbarton (talk) 00:37, 17 May 2023 (UTC)

Ok that did NOT work. That talk page does not preview. Please see: User:Johnjbarton/Electron_Diffraction_Sandbox. However I will move our discussion to the Talk page. Johnjbarton (talk) 01:21, 17 May 2023 (UTC)

Matter wave

Over at Matter wave and its talk page, we've been discussing miscellaneous possible improvements. Comments welcome. XOR'easter (talk) 01:49, 18 May 2023 (UTC)

Continuous or Discrete Spectrum

Continuous or discrete spectrum was recently created by merging "Continuous Spectrum" and "Discrete Spectrum." It strikes me as weird title for a weird article, but what do others think? PianoDan (talk) 05:10, 14 April 2023 (UTC)

Tagging @Fgnievinski who did the merge, in case they want to comment. PianoDan (talk) 05:12, 14 April 2023 (UTC)

IMO, under that name it is not a topic in the encyclopedic sense, and hence should not be an article per se (essentially it would be one or more dictionary entries). This comment applies equally to Continuous spectrum and Discrete spectrum, so the merge is not necessarily a bad idea. The real topic might be something along the lines of "real-world spectra", or "characteristics of observed spectra". Not being a subject-matter expert, my comment amounts to only that finding a suitable title might be the most sensible direction to go in. —Quondum 12:52, 14 April 2023 (UTC)

The two original articles were defined in contrast to each other. fgnievinski (talk) 01:14, 15 April 2023 (UTC)

That title definitely doesn't sit right. The topic is really just spectra, in the sense that the word is used in the physical sciences. Accordingly, I've merged the article into Spectrum (physical sciences) now. XOR'easter (talk) 17:12, 15 April 2023 (UTC)

That makes a lot more sense. —Quondum 17:47, 15 April 2023 (UTC)

The article could have been simply moved to Continuous versus discrete spectra, instead of merging to Spectrum_(physical_sciences)#Continuous_versus_discrete_spectra. It's a notable concept and it still deserves a dedicated article. fgnievinski (talk) 15:46, 25 April 2023 (UTC)

I totally disagree. That does not qualify as a topic. The "or"/"versus" change is not significant in this discussion. —Quondum 05:38, 27 April 2023 (UTC)

I did not see the Before state, but the current content on on this topic looks great to me. I propose you declare victory ;-) Johnjbarton (talk) 16:41, 18 May 2023 (UTC)

Cleaning up tagged articles.<<< Dead link

The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

---

On the project page Wikipedia:WikiProject Physics its say a Goal is

• Cleaning up tagged articles.

But what ever the link points to is no longer. Johnjbarton (talk) 22:43, 17 May 2023 (UTC)

I've replaced it with a link to Category:Physics articles needing expert attention. XOR'easter (talk) 01:48, 18 May 2023 (UTC)

Thanks! I'll delete this entry as resolved. Johnjbarton (talk) 14:58, 18 May 2023 (UTC)

It's standard to close discussions rather than deleting sections from talk pages, so that it's easier to see that a problem arose and was resolved. XOR'easter (talk) 16:47, 18 May 2023 (UTC)

Thanks! I looked for a "resolved" feature. Of course it's markup. I'll try it. Johnjbarton (talk) 17:44, 18 May 2023 (UTC)

Ok I tried the archive feature but it was not at all what I expected. I'll just leave this alone. Johnjbarton (talk) 18:02, 18 May 2023 (UTC)

While not strictly necessary to do so, I have hatted this as an example of how it would be done. Normally posts like these when they are resolved are just left for the bots to archive. Primefac (talk) 10:07, 19 May 2023 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Resolved

Just putting the {{resolved}} template at the top or bottom of the thread would probably work better in this context. —Quondum 11:42, 19 May 2023 (UTC)

Descriptor for theoretical particle or effects

Is there a consensus on whether to use hypothetical or theoretical to describe experimentally unproven but generally accepted concepts like strings and gravitons? Fermiboson (talk) 13:04, 24 April 2023 (UTC)

IMO, "generally accepted" is rather a generous description for these concepts; there is still a strong speculative/ungrounded component to them, unlike for many other particles before their discovery. —Quondum 14:56, 24 April 2023 (UTC)

I don't know about a consensus but these are usually excitations predicted to result from a quantum theory or quantum field theory. So "theoretical" or "predicted" makes more sense to me. Also I think it is the underlying quantum theory that is speculative or popular, not the particle excitations themselves. My two cents. --{{u|Mark viking}} {Talk} 17:28, 24 April 2023 (UTC)

I've done a little survey of the existing word use.

The article Graviton states in the lede:

• In theories of quantum gravity, the graviton is the hypothetical quantum of gravity

For String:

• In physics, a string is a physical entity postulated in string theory

However, we see other uses of the word being used to imply something different. For example:

• A tachyon (/ˈtækiɒn/) or tachyonic particle is a hypothetical particle
• A perpetual motion machine is a hypothetical machine that can do work infinitely without an external energy source.

where here "hypothetical" means "impossible according to current understanding of physics"; although admittedly, I cannot actually find a lot of uses of "theoretical" in a lede, although occurences in article text are more common. Fermiboson (talk) 17:50, 24 April 2023 (UTC)

In my opinion Wikipedia Hypothesis nails it:

Even though the words "hypothesis" and "theory" are often used interchangeably, a scientific hypothesis is not the same as a scientific theory.

By this argument, strings, gravitons, and tachyon are all hypothetical. None can be tested and corroborated. "String theory" is a name for a hypothesis, not an explanation; similarly it's the hypothesis of quantum gravity: no test or corroboration. Johnjbarton (talk) 16:56, 18 May 2023 (UTC)

Please do keep in mind that string theory has allowed mathematicians solve entire large rafts of previously-unsolved problems, and gain deep and broad insights into large tracts of mathematics. So, for example, results in algebraic geometry via Mirror symmetry (string theory) or even more simply affine Lie algebras and other "floppy things" that are not rigid (a la rigidity (mathematics)). So although popsci reporters tend to promote strings as a concept in physics, it's also been deeply important to mathematics, too. And there, there is no "experimental confirmation", there are only theorems. But popsci covers math results only poorly. 67.198.37.16 (talk) 05:15, 23 May 2023 (UTC)

quantum gravitation self-promotion

During reviews of several gravitation articles, I've noticed what looks like inappropriate self-promotion by User:Benur6991 (who seems to be (Redacted)). One example is Reissner–Nordström metric another at ‎Compactification (physics) another is Hawking radiation. The cited papers have all been published in refereed journals, and so appear to be "valid" results; however, they give undue weight to the author's results, as compared to the thousands of other papers published on these topics. For example:

• Reissner–Nordström metric is missing tons of (important) content, such as Cauchy and inner horizons, mass inflation, Penrose diagrams and more. To this article, User:Benur6991 added "quantum corrections" which, well, I guess they seem plausible, or maybe not (it's brand-new research, from 2022) and, at any rate, don't seem to be appropriate, given that we do not have any existing articles that adequately cover quantum-anything for gravitation.
• Compactification (physics) dates back to Kaluza-Klien in 1921, studied by Einstein in the 1930's through 1950's, had a huge explosion of interest in the 1980's with the supergravity theories, with thousands of mind-numbing articles published. The current article fails to review any of this. But we do read a claim that Campos Delgado did something for the first time in 2022. Again, undue weight and self-promotion.
• Hawking radiation also got the "quantum corrections" treatment. I'm unhappy, because that article is inadequate as whole. i.e. it never actually develops the idea fully and completely; spamming it with "quantum corrections" is deeply misleading.

My current plan is to notify this project, and do nothing more. Think of this as a mini RfD for certain sections of these articles. But if I find myself in some ugly, unhappy, cranky emotional state some days or weeks or months from now, I might take it upon myself to delete this content. Maybe, maybe not. (Poor-quality articles make me angry, but expressing anger is not socially acceptable, and so I bottle it up, like all enlightened souls.) If someone else can deal with this, that would be great! 67.198.37.16 (talk) 05:05, 23 May 2023 (UTC)

Reviewing the contributions of User:Benur6991, it seems clear that the account is dedicated only to self-promotion. Don't be shy about reverting his additions, the user is clearly WP:NOTHERE. Tercer (talk) 07:50, 23 May 2023 (UTC)

Hi, we are adult people, we can talk about it. So, regarding the Reissner-Nordstrom article, you say that it misses content such as Cauchy and inner horizons, mass inflation, Penrose diagrams and more. Well, then just add it! I just wanted to add a contribution about the quantum corrections. Maybe this could involve us wikipedians to work more on articles about quantum gravitation or to make people more interested in the topic.

About the Hawing radiation article, the only thing I said is that the Hawking formula will receive quantum gravitational corrections, which is true. The overall wiki article, as you said, can still be improved. This is what the modification was supposed to do. If you are interested, we can start to improve it even more and correct things already written there.

About the Compactification article, you are right, the wiki article was completely blank, so I thought to write something which is contained in that paper. If someone wants to contribuite with the history of Klauza, Einstein, supergravity and so on, then let's do it together.

Moreover, also other authors like Calmet and Kuiper were cited along Campos Delgado. Those modifications of the wiki articles were meant to improve the articles themselves, not to make self-promotion. What is more dangerous is that some pepole modify the wiki article incorreclty and without citing any publications in peer-review journals, this is something that happens rather frequently and we should take more care of that, in my opinion. In any case, I can delete the explicit name of the authors of the cited articles, if do you think this is better. Benur6991 (talk) 08:01, 23 May 2023 (UTC)

The intro to Hawking_radiation#Quantum_gravitational_corrections

"The Hawking formula of the black hole temperature is actually incomplete, because it does not take into account quantum gravity effects."

IMO this statement mixes theory and hypothesis. The established and largely verified theory of blackholes lead to a prediction of black hole temperature. The black hole temperature is a quantum effect in classical general relativity but not quantum gravity. Quantum gravity, as far as I am aware, remains hypothetical.

I wonder if the issue here is a matter of tone. The phrase "is actually incomplete" asserts a fact that cannot be verified: no experimental data on black hole temperature exists. I think a more neutral introduction sentence could be:

"Effective field theory, developed for quantum gravity, predicts corrections to the Hawking black-hole temperature."

In general I think the Problems section would be better as four sentences that pointed to four paragraphs in other articles. Two or three paragraph summaries often seem too long to help readers decide if they need more but too short to satisfy when the decide 'yes'. But I understand such changes are much harder, so file under "free advice". Johnjbarton (talk) 16:24, 23 May 2023 (UTC)

I concur with the need to rephrase the opening line to Hawking_radiation#Quantum_gravitational_corrections. And even aside from any self-promotion considerations, I don't think the long formula at the end of that section contributes much understanding. So, the temperature of a charged black hole is, to quartic order, some long string of LaTeX... and that means what, exactly? XOR'easter (talk) 17:42, 23 May 2023 (UTC)

The section in Compactification (physics) was definitely over the line. XOR'easter (talk) 17:39, 23 May 2023 (UTC)

Replying specifically to User:Benur6991, I want to spell out some important basic assumptions. More or less every physics article on wikipedia covers topics which have thousands of published journal articles that touch on that topic (these are called "primary sources"). There are dozens or hundreds of textbooks or popular review articles that touch on the topic (these are "secondary sources"). As a general rule, Wikipedia articles should cite secondary sources, not primary sources. Primary sources are OK, when they are historically significant or seminal in some way. Otherwise, picking out just one article, out of thousands, gives undue weight that, in general, is not deserved. Put it more rudely and bluntly: why should your articles be cited, and not those of Ed Witten or Gerard 'tHooft? Surely their work is far broader and deeper and more important?

Wikipedia is meant to provide a coherent development of topics, not unlike what one might hear in a seminar or a classroom. They should be surveys or reviews. What you've done is to come in, spray-paint some graffiti, and then leave. This is a misdemeanor; this is not helpful editing. It puts a burden on us to clean up that graffiti. 67.198.37.16 (talk) 00:25, 24 May 2023 (UTC)

May I request a little less aggressive tone? Contributors are important to Wikipedia. I think we should assume good faith and encourage participation. The contributions did not look to me anything like graffiti; the record of contributions stretch over a year. Providing links to Wikipedia guidelines would be much more helpful than assertions. Johnjbarton (talk) 01:02, 24 May 2023 (UTC)

Project Process docs/outline?

Wikipedia:WikiProject Physics/Article alerts looks like a categorized community TODO list of some sort. Is there any documentation on the meaning of the entries, how they are created, progress, and resolve? Johnjbarton (talk) 15:42, 23 May 2023 (UTC)

At the bottom of the page you'll see that the article alerts are bot-generated summaries of various types of article activity. They are useful summaries of the current state and recent history of articles under consideration for various actions. Many of us do find them useful as guides for where we may be able contribute on recent article issues. Documentation can be found at the bot page. --{{u|Mark viking}} {Talk} 17:24, 23 May 2023 (UTC)

Thanks. I boldly edited Wikipedia:WikiProject_Physics/Intro to link to the workflow doc directly. I think adding this to the top of Article alerts page would be possible and better but riskier for me. Johnjbarton (talk) 01:24, 24 May 2023 (UTC)

Reviews vs published physics articles.

I wonder how to interpret WP:PRIMARY vs WP:SECONDARY for physics pages. If I go by what I read there literally then I would end up with one reference to a review article for many topics. Then the page will appear to be under-referenced or repeatedly reference the same review. This also forces the very interested reader to read the review and sort out the primary.

But the alternative is to reference the primary publication.

Is a reasonable compromise to reference both, that is the review for the larger category and the primary at the sentence level? I think this is in the spirit of the guidelines as the review provides the "provides thought and reflection". Johnjbarton (talk) 01:43, 24 May 2023 (UTC)

Repeatedly citing the same review article (or textbook, etc.) isn't bad, necessarily. One can use the {{rp}} template to add a little notation after a footnote giving a more precise location within a source. It's also reasonable to provide primary as well as secondary references. XOR'easter (talk) 02:29, 24 May 2023 (UTC)

Ok thanks. I'll try citing the review and the primary; seems like a good idea anyway.

I also realized that the way I judge primary papers is with citations. Many citations means a work is WP:NOTABLE and the body of citations acts as thoughtful filters like WP:SECONDARY. Johnjbarton (talk) 15:19, 24 May 2023 (UTC)

This is more involved, but you can also cite secondary discussion of the topic in primary sources, e.g. when it comes up in the intro/background or discussion sections of a research paper on a related subject. JoelleJay (talk) 17:11, 24 May 2023 (UTC)

You can also cite, for each instance, the page number or the section title or the chapter. So, in italics. Some citation templates allow this; with others, you can do it by hand, adding (See page 42.) as part of the cite. 67.198.37.16 (talk) 16:36, 26 May 2023 (UTC)

An offer to provide illustrations

A user has here offered to provide illustrations, and initially expressed interest in astrophysics. If anyone knows of articles in need of illustrations, you may want to contact that user. --Bensin (talk) 19:04, 27 May 2023 (UTC)

Thank you. Unfortunately it seems that User:Deevad is no longer with us:

11:42, 14 August 2022 Explicit talk contribs deleted page User:Deevad (U5: Misuse of Wikipedia as a web host) Tag: Twinkle (thank) Johnjbarton (talk) 23:00, 27 May 2023 (UTC)

The user has contributed after that, see Special:Contributions/Deevad. --Bensin (talk) 18:18, 28 May 2023 (UTC)

RfC re periodic table

Editors interested in the categories and colors of the periodic table are invited to participate in a discussion at WT:WikiProject Elements § RfC on the classification of chemical elements on the periodic table. YBG (talk) 14:13, 24 May 2023 (UTC)

The discussion about a periodic table with no colours was unanimously opposed and has been closed.

Discussion remains open on:

• Side discussion re venue
• Scary ambiguity?
• Black and white labelled PT (noting not all elements are shown as the same colour).

--- Sandbh (talk) 07:52, 31 May 2023 (UTC)