# Wikipedia talk:WikiProject Physics

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WikiProject Physics
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## Isotopes in medicine

I'll pick up on this stub over the next few weeks and add a couple more sections/ info in it. Working draft is in my sandbox here.Careless Torque (talk) 22:47, 20 August 2020 (UTC)

You may consider splitting the article into sections based upon pharmacological or imaging use, as they are radically different topics. There is also not much information on there about what the isotopes are used for in the fist place. For the medical imaging compounds, this shouldn't be too difficult to give an overview of, and will go a long way in explaining the relevance of the topic. It may help to add some references to standard medical physics textbooks. Also, nuclear medicine and medical imaging have their own pages, which already cover a lot of the content that should be in this page. The nuclear medicine article even has a table of common isotopes used in nuclear medicine. Just friendly suggestions. Good luck! Footlessmouse (talk) 00:25, 21 August 2020 (UTC)
Thanks a lot for the suggestions Footlessmouse - I'll make the changes in the sandbox rather than main article for now but definitely splitting it as you suggested. Careless Torque (talk) —Preceding undated comment added 23:06, 21 August 2020 (UTC)

## International Center for Relativistic Astrophysicsand ICRANet

Hi. I was working on developing International Center for Relativistic Astrophysics when I found ICRANet which looks like it is an article about the exact same organization. Is that correct? Do these two pages cover the same subject? Best, SJTatsu (talk) 16:36, 2 September 2020 (UTC)

It looks like the answer to your question is "no". ICRA is one institute, ICRANet is a group of them. Primefac (talk) 19:04, 2 September 2020 (UTC)

ICRANet was created earlier and International Center for Relativistic Astrophysics looks like it was created without knowing the first one existed which makes sense because the title is an abbreviation. So neither reference the other though they both link to the same source material. Both cover the same ground, same members, same meetings, etc. ICRANet is more developed. They are built like they aren't related. SJTatsu (talk) 20:19, 2 September 2020 (UTC)

## Large addition at Elastic collision

I had undone a large unsourced addition of content at Elastic collision ([1]). User 173.206.33.141 restored the content with a source ([2]) to which I have no unpaid access ([3]). Can someone who does have access to the source please have a look at the new content and verify whether the edit was appropriate (no copyright violations, no additional original research, sufficient secondary sources, no COI, ...)? User was notified about this on their talk page. Thanks. - DVdm (talk) 19:43, 2 September 2020 (UTC)

@DVdm:, I wanted to just email you the paper, but I don't think that's an option. The paper was published in 1989 and has had a total of 4 references to it over the past 20 years (it also only cites 7 articles) -- it is not notable. The entire addition is trivial, if it is necessary, it should have a textbook reference, as any graduate level book in classical mechanics would have this information. I don't think anything below "In an angle-free representation," is necessary. Readers can understand what a cosine term is and maybe a dot product, but it is not necessary to mention the inner product or introduce notation for it, IMO. On the line just above that, there are 6 valid references to valid sources covering how the equation is derived. To answer your actual question. There are no copyright violations, but you could argue that this would count as additional original research, it could go either way. The article is focused on "superballs". It does include a section on point masses colliding in 1,2, and 3 dimensions and a point mass colliding with a rigid body in 2D. It does not discuss the collisions of 2 rigid bodies in 2D. The article also does not use the same notation as the answer, and doesn't explain anything other than use the conservation laws. The "derivation" is just 6 mathematical statements with no explanation in between. Simply plug variables into the conservation laws. The article explicitly cites Classical Mechanics: A Modern Perspective, by Barger and Olsson, if this section is required, that is the reference that should be looked up and used. Considering it has only ever been cited 4 times, I would venture to guess there is a good chance COI is involved. I would re-delete it and invite the IP user to start a talk page discussion on the matter. Footlessmouse (talk) 08:26, 3 September 2020 (UTC)
thanks. The user was invited ([4]) to come here for comments, but they haven't shown up. I will not re-revert the content to avoid edit-warring. Feel free to do so with a pointer to this discussion in your edit summary. I will also leave a pointer to this on the article talk page. Cheers. - DVdm (talk) 08:35, 3 September 2020 (UTC)
The derivation is important for programmers. There is more I want to say, but defending every edit is exhausting. Please leave it out. 173.206.33.141 (talk) 19:44, 3 September 2020 (UTC)

## AfD for Krausser–Samwer–Zaccone equation

I put up an AfD for Krausser–Samwer–Zaccone equation, that was discussed here before. After taking a closer look, it seems pretty clear to me that it's a case of WP:PROMOTION. Tercer (talk) 09:47, 3 September 2020 (UTC)

## AfD for Minimon and Maximon

I nominated Minimon and Maximon (particle) for deletion. Tercer (talk) 11:57, 6 September 2020 (UTC)

## RfC: Merge/redirect proposal

I've opened a proposal to merge/redirect Statistical physics to Statistical mechanics. –LaundryPizza03 (d) 13:55, 7 September 2020 (UTC)

where is the RfC? Xxanthippe (talk) 22:25, 7 September 2020 (UTC).
Talk:Statistical mechanics#RfC: Merge/redirect proposal. XOR'easter (talk) 00:55, 8 September 2020 (UTC)

## Draft:Continuous spin particle

I feel like there isn't enough here for a full article, but it might be worth chucking into something existing. However, I can't think of where would be a good place to merge it. There has been a surprising amount of research done on a massless particle that has never been observed (though I doubt it will be as sought-after as the Higgs boson) and likely never will be. Basically, theoretical/particle physics was never really in my wheelhouse, so a second opinion is appreciated. Primefac (talk) 22:08, 9 September 2020 (UTC)

## 2020 publication Zitterbewegung and self interactions

Can somebody verify that the inclusions of this IP are legit?: [5] and [6]. Seems to be based on a specific Springer publication [7].--ReyHahn (talk) 12:38, 10 September 2020 (UTC)

They're not legit, they're complete nonsense. Tercer (talk) 13:09, 10 September 2020 (UTC)
Wow, the IP user has been adding the same paper to every article in Wikipedia it's remotely related: Special:Contributions/212.128.3.46. I've checked the IP address, it belongs to the University Rey Juan Carlos, where the author of this paper works. So with all likelihood it's him. Tercer (talk) 15:27, 10 September 2020 (UTC)
I've reverted and left a COI warning. --Izno (talk) 16:09, 10 September 2020 (UTC)
It looks like they've tried this before, too. XOR'easter (talk) 16:10, 10 September 2020 (UTC)
And also from another IP address: Special:Contributions/146.158.171.99. This guy is a persistent spammer. Tercer (talk) 17:53, 10 September 2020 (UTC)
From what I can see he's just editing at work versus home or something. Both addresses are in Madrid though one looks like a sports complex? I wouldn't worry about the 146 IP for now. --Izno (talk) 18:02, 10 September 2020 (UTC)
Huh? No, the 146 IP belongs to Jazztel, a mobile phone company. In any case, it seems like he's just editing from different places in Madrid. I also found this IP: Special:Contributions/37.10.142.149. Tercer (talk) 18:19, 10 September 2020 (UTC)
Hi guys. I am not a spammer, but a professor at the university in Madrid. I am just trying to upload a reference to a paper published in Q1 journal, with recent findings in the field of electrodynamics and quantum mechanics. They are legit, because the mathematical demonstrations of the paper are exact and have been subjected to peer review for six months. They are as sensical as Maxwell's electrodynamics, since there is nothing else in the paper but that. Please reconsider their value, it will be for the good of science. Some people are trying to boicot knowledge, and Wikipedia must fight against that. Alvaro12Lopez (talk) 08:13, 11 September 2020 (UTC)
@Alvaro12Lopez, this is a conflict of interest, please see WP:COI. Given that there is a conflict of interest, I believe the best way to proceed is to begin a new section on the talk page of that article, declare your conflict of interest, and lay out the reasons why you believe other editors should include the material in the article. Thoroughly explain what should change and why. If other editors agree, the changes will be made. Stating that we should fight against a boycott of knowledge does not provide a sufficient reason for inclusion, and saying the paper's findings is as sensical as Maxwell's papers is meaningless; Maxwell's equations are not included in Wikipedia due to their sensibility, but rather their notability. Please see WP:notability. Footlessmouse (talk) 08:35, 11 September 2020 (UTC)
Alright. I'll do just as you suggest, page by page. I did not know the exact procedure and, since I had seen a lot of weird physical ideas in many pages, even whole pages dedicated to obscure theories, certainly notable and nonsensical ideas, I thought people uploaded directly their works, as long as they were published in notable journals. Now I see there is a procedure, which is for the best of Wikipedia, of course. Perhaps you should not allow the Edit button before going through the Talk section. "Temptation I can't resist", quoting Oscar Wilde. Thanks for your help once more and excuse my ignorance. Alvaro12Lopez (talk) 08:45, 11 September 2020 (UTC)
@Alvaro12Lopez: you have added a citation to your work, with nearly identical text, to several articles in Wikipedia. This is considered spam. See WP:CITESPAM. Wikipedia should report on work that is notable, but you're trying to make your work become notable by inserting it in Wikipedia. It doesn't work like this. You have to do it the hard way, get your work noted and accepted by the scientific community, and then it will be appropriate to cite it in Wikipedia. If, as you say, some people are boycotting your work, this is a reason to keep it out of Wikipedia. According to Google Scholar, your supposedly revolutionary work has only ever been cited by yourself [8]. That doesn't cut it. Tercer (talk) 10:02, 11 September 2020 (UTC)
You are totally right, Tercer. I will follow your advice and do it the impossible way. Do not worry! I accept the rules, once they are known. Now I have no doubt that all the references appearing in Wikipedia are abundantly cited, even that plethora that are cited from the arXiv. It is just that the Edit button was so suggestive to me... But you are right. Anyway, I also promise you not to say of nobody's work that it is nonsense without even reading it before. My word on that too! If that is not boycott, at least it is unfair, rude and unpolite. Sincerely, Alvaro12Lopez (talk) 10:27, 11 September 2020 (UTC)
: Just so you know, secondary and tertiary sources are generally required for bold claims. Primary sources tend to be qualified, as you are not allowed to "analyze, evaluate, interpret, or synthesize" them. (See WP:PRIMARY) Many of the references that point to the arXiv are, in fact, published papers. For obvious financial reasons, it is beneficial to the readers of Wikipedia to leave a link to the publicly-available version of the article. That being said, if you notice a reference seems sketchy, you can replace it with another or, in some cases, remove it. I have deleted references to the arXiv which were unnecessary and were never published. If no one reverts your edit, then the community agrees. Otherwise, it can be discussed on that page's talk page. Please feel free to help fix any mistake you see which does not involve a COI. Footlessmouse (talk) 11:08, 11 September 2020 (UTC)
: One last thing, though physics is a hobby for some of the editors here, you will find that many of the editors in this project are physicists with degrees and careers in the field. You should avoid insinuating fellow editors are ignorant of the topics at hand, it will never help your argument. Your comments are very aggressive. For a more detailed understanding of notability in science, you can see WP:NPOV and WP:FRINGE. Points of view and scientific findings that are not widely supported by the scientific community are fringe, and likely have no place in an encyclopedia. Footlessmouse (talk) 20:35, 11 September 2020 (UTC)
Forgive my overreaction, but when somebody accuses a work published in a Q1 journal of nonsense and illegitimacy, such journal having an impact factor (and therefore notability, at least as a journal) that is well above the impact factor of many of the papers appearing in the webpage notes, among which at least eight references are dubious according to your standards (e. g. 63, 75, 109; but please do not erase them, I do not think there is need to harm the authors at all, since their contents are interesting and relevant to the topic), one has the feeling that decisions based on insinuations are at stake here. Unjustified accusations can bias people's judgments to take decisions, wether right or wrong. And wherever you go, do what you see. Nevertheless, I thank you for your kind attention and respectful words. I also apologize for the misunderstanding, because it was my fault. I should have read the publication rules before (no matter what), and not just mimic what I had figured, as a user of Wikipedia, that people frequently do. It won't happen again, now that I am aware of notability rules and that everything must conveniently go through the Talk section before edition. It should be obligated, even before erasing material as well, in my modest opinion, to counterbalance Matthew's effect. Sincerely Alvaro12Lopez (talk) 13:12, 12 September 2020 (UTC)

See Talk:Self-oscillation#Inserting an application to electrodynamics, Talk:Functional differential equation, and Talk:Limit cycle#Applications. In my view, the requested addition would be inadmissible at all three per WP:PRIMARY and WP:UNDUE, regardless of technical correctness or lack thereof. Wikipedia is not the place to bring attention to novel ideas; we summarize the scientific consensus as it exists. XOR'easter (talk) 15:55, 16 September 2020 (UTC)

## Talk:Tonne

Previous content related to sub-units was deleted merged. If good then good. In ictu oculi (talk) 07:55, 12 September 2020 (UTC)

## A History of the Theories of Aether and Electricity

Hi all, I created this article A History of the Theories of Aether and Electricity as I noticed there was no page for it on Wikipedia, even though I believe it is undeniably notable. As I suspect many of you are are more familiar with the book(s) than I am, I wanted to invite you all to edit the page. I do not own the second edition of the book, so I could only post quotes from review articles for that section. The special relativity controversy section was copied originally from the E. T. Whittaker article. The article has already been reviewed and is now just past stub status. Also, the book is referenced on dozens of articles, I have added backlinks to several of these already. As the 1910 version of the book is in the public domain now, I believe the article is very beneficial for any reader looking into the history of physics, especially electromagnetism. Footlessmouse (talk) 13:00, 12 September 2020 (UTC)

## Perturbation theory

In 2017, about 2/3rds of the article on perturbation theory was blanked in this series of edits. Apparently, no one noticed, or, at least, no one reverted them or challenged them. As a result, we have an article on perturbation theory that does not actually say what perturbation theory is, and a history-of-perturbation-theory section that is missing pretty much all of the actual history, (e.g. nary a breath about 20th century developments, which range from the invention of Feynman diagrams to represent perturbative series diagrammatically, to important results on weakly chaotic systems, like the KAM torus. It would hurt my head to try to restore that content, but something needs to be done.

If putting equations into the lead article is too much of a strain, perhaps there could be two articles, e.g. one on perturbative series that actually gives the series to 2nd order? Or maybe three: quantum perturbation series that gives the standard-college-textbook solution for Zeeman effect (which the Zeeman effect article does not provide) and a second article on classical perturbation series that uses e.g. planetary motion as an example? Something about phase-locking and the small divisor problem would be nice, since this is a topic of active research in e.g. the transition of water waves to turbulent flow. (which is what I wanted to write about, when I got distracted by the fact that there are no WP articles on the prerequisite topics...)

I dug around some more an posted suggestions on the talk page. Translating the German page would be an easy way to get an article on quantum perturbation series. The Chinese and Ukranian versions could provide a shorter, simple intro, as the German version is ...loooong. For the chaotic-motion part, there is a reasonable Scholarpedia article on the topic. I have not yet stumbled over anything good on the classical theory. (The German WP even has one for general relativity, but it doesn't say much, other than mentioning Lie derivatives. ) 67.198.37.16 (talk) 17:04, 14 September 2020 (UTC)

Some of that material blanked from the page was more textbook-like than is really suitable for a Wikipedia article. Working step-by-step through a detailed example isn't what our articles are for, generally, and such exercises are seldom suited for articles on broad topics like perturbation theory. That said, much of the blanked material could be restored, I think. XOR'easter (talk) 18:07, 14 September 2020 (UTC)

For some unclear reason, I started writing Draft:Resonant interaction and so far what I've written is in a pre-pre-pre-draft form. But before I write more, a key question: are there existing articles that already cover this topic, under a different name? This is a kind-of sub-topic of perturbation theory (ergo the post immediately above). Searching -- inverse scattering problem is stub, and S-matrix talks only about QFT and nothing at all about generic partial differential equations. Resonance is very long and deals only with the most basic resonant ODE. It has a long list of see-also articles, but none seem appropriate. I'm not really familiar with WP's collection of PDE articles. Before I write much more, I am wondering if it is worth my time to .. write more, or if this is a pointless quest. (and I invite those who are excited by this, to edit the draft!) 67.198.37.16 (talk) 20:33, 14 September 2020 (UTC)

I think I've written as much as seems reasonable for Draft:Resonant interaction; I would like a request for a review, and/or for someone to move this to main article space. I will post this request to WP:Math as well, as some parts, especially the three-wave equation, have seen intensive study, via inverse scattering methods, for the last 5-6 decades. (They have a Lax pair, specifically, a 3x3 Lax pair). Actually, I'm thinking its best to split the three-wave resonant interaction into it's own article, the Draft:Three-wave equation. 67.198.37.16 (talk) 21:32, 16 September 2020 (UTC)
It looks like it has already been promoted to mainspace. Congratulations, and nice work on the article. --{{u|Mark viking}} {Talk} 02:30, 17 September 2020 (UTC)

## Crystalline Coatings

I noticed this in the new-article report and tagged it as a likely instance of a COI:

XOR'easter (talk) 20:51, 14 September 2020 (UTC)

I think this is a good candidate to merge into the Optical coating article, which itself is not very well filled out (the only optical coating article that is substantial is Anti-reflective coating, as far as I can tell). I think we should merge it into a section in that article and sort through the references to see which are appropriate. As more content is added over time, it may eventually claim its place as a separate article again. Footlessmouse (talk) 22:03, 14 September 2020 (UTC)

## Editing the G section

Does graviton (Hypothetical particle) fit into the section for capital G? Gioguch (talk) 22:21, 15 September 2020 (UTC)

Unfortunately, as with many other symbols, capital "G" is badly over-loaded (used for multiple different purposes) including but not limited to: the gravitational constant in Newton's gravity, the graviton, the metric tensor, and the Einstein tensor. And these are just some of the ways it is used in connection with gravity. JRSpriggs (talk) 01:26, 17 September 2020 (UTC)

## Draft:Three-wave equation

I've split out Draft:Three-wave equation so that it stands on it's own two feet. I'd like to request a review and move to article main-namespace as appropriate. 67.198.37.16 (talk) 17:55, 17 September 2020 (UTC)

I gave it a quick reference spitshine (this was not a content review). One thing that stands out is you are citing InTech Open ("Frequency Conversion Based on Three-Wave Parametric Solitons"), which is a vanity press, does not constitute a reliable source suitable for Wikipedia. Headbomb {t · c · p · b} 19:17, 17 September 2020 (UTC)
Oh, eww. I thought I gave a URL for the actual paper, and not this predatory-press thing ... maybe the original URL should be restored!?! Referencing a scam site is indeed a terrible idea! 67.198.37.16 (talk) 22:25, 17 September 2020 (UTC)
It seems that you removed many or most of the URL's to the actual papers, leaving only the citations... this is kind of useless, it forces the user to then troll through their favorite search engine on a hunt for the actual papers! It's actually a lot of pain-staking work; I made a point of hunting down all of the references, and reading through all of them, to make sure they're actually high quality and on-topic. Otherwise, there's just a giant ocean of stuff that's ... too far off topic. 67.198.37.16 (talk) 22:37, 17 September 2020 (UTC)
The DOIs are there, and I kept the links that lead to the free full versions of record of papers. This encourages editors to find links to full versions that are freely available. Headbomb {t · c · p · b} 22:39, 17 September 2020 (UTC)
Oh, I'm sorry, I looked again, I made a false accusation. (I'm a hot-head.) I got confused ... all the blue links in the references obscured where the actual content is... 67.198.37.16 (talk) 22:46, 17 September 2020 (UTC)
Umm, and now I see you removed the predatory-press cite completely... Why? Why not just cite the original publisher, instead of getting tangled into the predatory-site thing? Just because someone ripped off the paper does not invalidate the paper ... Anyway, there seems to be plenty published on the topic, e.g. page-one of search engine results gives: I. Breunig, “Three-wave mixing in whispering gallery resonators,” Laser Photon. Rev. 10, 569-587 (2016). ... which I can't (easily) read as I'd have to go get my library card renewed (ugh). And anyway, seems that three-wave mixing is not a red-link, but rather a redirect to non-linear optics, of which a rather hefty portion is devoted to the three-wave resonant interaction. The goal was to simply say "oh hey, if you are interested in three-wave resonances, check it out -- even the non-linear optics people are into it!" rather than a "citation needed"; this is not meant to be controversial, its meant to be readily and easily verified by rudimentary means. 67.198.37.16 (talk) 23:24, 17 September 2020 (UTC)

## meta-question -- three-wave mixing

This is a meta-question, which seems tricky to pose. Many articles on WP have an "informal introduction" with the intent of "explaining it in a way that a high-school student could understand". Many do not, and writing such sections is hard, as the result can be perceived as being not rigorous, or biased, or misleading. As a general rule, such sections tend to create flame-wars between experts and non-experts, because, once-written, the non-experts start adding in random gunk. The meta-question is then: "how does one proceed when one does not have a textbook that can be cited?"

To provide a concrete example that can be pondered: I am tempted to redirect three-wave mixing to Draft:Three-wave equation, after creating an "informal introduction" section that would look something like the below. As you read it, you will see that it should be understandable by beginners, and yet also chock-full of oversimplifications and glosses and inaccuracies. (Stuff that mathematicians hate, but passes for gold in the physics world). The meta-question again: how to deal with this?

### Informal introduction

Linear differential systems have the generic form ${\displaystyle D\psi =\lambda \psi }$  for some differential operator D. The simplest non-linear generalization of this is ${\displaystyle D\psi -\lambda \psi =\varepsilon \psi ^{2}}$ . How can one solve this? Method A is perturbation theory and method B is S-matrix. In the S-matrix approach, one considers particles/ aka plane waves coming in from infinity, interacting, and then moving out to infinity. The simplest such interaction is the three-particle interaction, because in the two-particle case, there is no interaction (i.e. the particle that went in is the same one that comes out). Writing ${\displaystyle \psi _{1},\psi _{2},\psi _{3}}$  for these three waves moving from/to infinity, this simplest quadratic interaction (called a chi-two interaction by the photonics people) takes the form of ${\displaystyle (D-\lambda )\psi _{1}=\varepsilon \psi _{2}\psi _{3}}$  and cyclic permutations thereof. This is called the Draft:Three-wave equation, and all quadratic resonant interactions can be written in this form (for small enough ${\displaystyle \varepsilon }$  and other appropriate assumptions). You can also write ${\displaystyle (D-i\partial /\partial t)\psi _{1}=\varepsilon \psi _{2}\psi _{3}}$  for a time-dependent version.

I think that it is self-evident that the above paragraph would drive many readers absolutely apoplectic, due to its lack of rigor. Having to write something like the above would make most math people absolutely cringe. It takes a lot of self-confidence and bluster. Yet, this is the kind of "informal intro" that most WP article require. OK great! So lets write these. Oh wait, how do we avoid the rash of [citation needed] that will follow every sentence? I have a gazillion math books on my shelves, I doubt any of them say something like the above. Maybe something by Martin Gutzwiller? In my vivid imagination, I imagine there are many textbooks that say exactly the above, but which ones? Where?

I'm kind of not sure why I am asking the above question. I'm loosing track ... Let me rephrase that... here we are, in 2020, and WP has oodles of articles on PDE's and ODE's and non-linear-this and non-linear-that and dynamical this-and-that. Yet I seem to be the very first one to create an article on what is arguably the simplest, most-direct and plainest non-linear system, ever?[citation needed] What is it about the above italicized even-college-freshmen-can-grok-it explanation that is so reprehensible, so unsupportable, so vile, that, up until 2020, no WP article has ever stated it? That I have to work up the gumption to post it here? What am I missing? 67.198.37.16 (talk) 00:39, 18 September 2020 (UTC)

Writing introductions to technical subjects is indeed a challenge. The guidance we usually use for this is in WP:TECHNICAL. Among the good advice in there is "write one level down". I think your informal intro is a reasonable example of that--take what might typically be a graduate level subject and attempt to write an intro that an undergraduate could understand. Lack of rigor is absolutely fine in an introduction, as we are writing encyclopedic summaries of topics. Readers can check out the sources cited if they want all the details. --{{u|Mark viking}} {Talk} 02:38, 18 September 2020 (UTC)