Wikipedia talk:WikiProject Physics/Archive July 2019

Neven's law
I noticed Neven's law via the new articles bot and prod'ed it on the grounds that it's a coinage by one guy a few weeks ago. The prod was declined; maybe someone here has an idea for how to improve it, redirect it, etc. I'd be a "delete" !vote if it were at AfD &mdash; a few pop-science stories can't cover up the essential neologism-ness of it &mdash; but my Wikipedia time will be too intermittent for the next few weeks for me to manage an AfD discussion myself. XOR&#39;easter (talk) 20:32, 29 June 2019 (UTC)
 * Not only is the term only a few weeks old, but "Nevin's Law" appears to be based on only a few months of data. Neven's law has been redirected to Hartmut Neven.--Srleffler (talk) 03:22, 30 June 2019 (UTC)
 * See discussion at Talk:Hartmut Neven--Srleffler (talk) 03:27, 1 July 2019 (UTC)

Cabreras
Blas Cabrera Felipe (BCF) is very well known Spaniard for his contribution to physics. Blas Cabrera (BCN, N for Navarro) is a more recent physicist, son of another seemingly important physicist Nicolás Cabrera (NC) but not related to Cabrera Felipe. Both BCF and BCN published under the name of "Blas Cabrera", I suggest to move the more famous BCF to Blas Cabrera namespace and BCN to "Blas Cabrera Navarro" or something else as it is done in Spanish Wikipedia. Also, it would be nice that somebody check the notability of BCN and NC.--MaoGo (talk) 15:30, 9 July 2019 (UTC)

Property:P1127 (isospin z-component)
Likely Wikidata swallowed someone’s mistake. The property’s talk page denotes it as «$T_{3}$» – seemingly the weak isospin’s main component. On the other hand, example usage currently specifies certain value for neutron, a baryon. Look: for a massive particle, and of these firstly for weak-interacting SM’s elementary particles, $T_{3}$ is technically uncertain because changes irregularly under P-symmetry. Namely, ±½ values are assigned for the active chirality (left for particles, right for anti), whereas for the sterile chirality (right for particles, left for anti) $T_{3} = 0$. Neutron is composed of three (massive) quarks, by the way; it’s $I_{3}$ (not $T_{3}$) which is defined for it. Suggestions by particle experts? Incnis Mrsi (talk) 12:41, 10 July 2019 (UTC)
 * My suggestion would be to mostly to delete this stuff from Wikidata entirely. $$\Delta^{++}$$, $$\Delta^+$$, $$\Delta^0$$ and $$\Delta^-$$ have $$T_3/T_z/I_3/I_z$$ (whatever you want to call it) values equal to $$+3/2, +1/2, -1/2, -3/2$$ respectively. We don't have an article on each of these individual articles, we have one article about the Delta baryon isogroup. Isospin projection is a property that's only meaningful to hadrons made of quarks (because isospin 'projection' really is $$n_u - n_d$$, and irrelevant elsewhere). &#32; Headbomb {t · c · p · b} 20:28, 10 July 2019 (UTC)
 * They have certain workaround permitting for multiple flavours under one entity. OK, my question is now narrower – does a consensus here exist that P1127 really refers to $I_{3}$? That “$T_{3}$” was an egregious mistake? Or the current usage has signs of ambiguity? Incnis Mrsi (talk) 21:00, 10 July 2019 (UTC)
 * What variable you choose to represent the isospin "projection" along a "third axis" is always going to be a choice. From what I can surmise I is more common than T, z/3 is about evenly split. Likewise, weak isospin also has mixed usage, although there T3 seems dominant. &#32; Headbomb {t · c · p · b} 22:21, 12 July 2019 (UTC)
 * Sadly the essence of the problem was ignored here. Based on the current use of P1127 (see also a long URL in the box) conclude that Wikidata contains no useful values for weak isospin. The only thing in the list for which weak isospin is relevant appears to be  having $I_{3} = 0$ anyway as for any truly neutral particle. Hence,  remove boldly all references to the weak interaction in P1127. Incnis Mrsi (talk) 17:28, 14 July 2019 (UTC)

Big Crunch
Some recent changes (example) to this article should probably be reviewed by members of this project. Thank you. Peacock (talk) 14:04, 14 July 2019 (UTC)
 * Amazingly, removed some valuable stuff (such as coalescing singularities which were theorized e.g. by Roger Penrose), whereas left utterly ignorant fluff unchanged. “If the universe's expansion speed does not exceed the escape velocity…” and “… there is no matter beyond the maximum expansion point, eventually all matter would begin to travel inwards”. There are no “escape”, “beyond” and “inwards” in a Friedman-style universe. Incnis Mrsi (talk) 19:42, 14 July 2019 (UTC)

Bogdanov affair
I've been taking intermittent thwacks at improving the page Bogdanov affair, and I think it's actually decent for a treatment of a rather murky topic. It could use more eyes, though (there's probably bad phrasing that I've read too many times and just become acclimated to, et cetera). Also, there's an IP editor who is oddly insistent that the lead shouldn't have links to later sections (despite the Manual of Style), but that's just life in this strange place called Wikipedia. XOR&#39;easter (talk) 02:32, 11 July 2019 (UTC)
 * The discussion has been rather productive; we're getting into territory where some references have mysteriously disappeared from the Internet, so if that kind of intrigue is your thing, please do join in! XOR&#39;easter (talk) 01:23, 13 July 2019 (UTC)
 * I made a request for semi-protection for headache-prevention reasons. In happier news, LexisNexis turned up some things that are seemingly not available on the public web. XOR&#39;easter (talk) 23:24, 15 July 2019 (UTC)

Draft:Special Theory of Ether
I don't actually know what the protocol is for marking Drafts as things made up one day, but Draft:Special Theory of Ether qualifies. The sources aren't just primary; they're from viXra and SCIRP. XOR&#39;easter (talk) 21:20, 14 July 2019 (UTC)
 * PROD or MFD would be the way. &#32; Headbomb {t · c · p · b} 22:26, 14 July 2019 (UTC)
 * Can't PROD a draft, has to be MfD. &spades;PMC&spades; (talk) 22:35, 14 July 2019 (UTC)
 * You can just reject rather than decline and let G13 take care of it in 6 months. --Izno (talk) 01:22, 15 July 2019 (UTC)
 * Sounds like a re-invention of the Lorentz ether theory. --mfb (talk) 23:01, 15 July 2019 (UTC)
 * It is now at MFD (not put there by me). XOR&#39;easter (talk) 23:24, 17 July 2019 (UTC)

WikiProject Physics/Article alerts update
As a heads up, the alerts will now report proposals for mergers and splits, as well as AFC submissions. There's a bit of a backlog, but now we have a way to track it! &#32; Headbomb {t · c · p · b} 02:03, 31 July 2019 (UTC)

Discussion about old AfD Articles for deletion/Covariance mapping
Here (I only noticed because I was pinged). XOR&#39;easter (talk) 20:09, 31 July 2019 (UTC)