Wikipedia:Reference desk/Archives/Science/2023 February 26

= February 26 =

Theta Muscae
I recently removed information about an optical companion of this star because the source used failed verification — in particular, it did not mention Theta Muscae at all. Any information you can find about this "Theta Muscae B" object? –LaundryPizza03 ( d c̄ ) 01:17, 26 February 2023 (UTC)


 * The cited source mentions a system HD 204 827 AaAb, writing: "This object was not present in version 1 of GOSC. Mason et al. (1998) give a separation of 0″.12 and a Δm = 1.2 for the Aa + Ab system. B is more than 3 mag fainter. In Maíz Apellániz et al. (2004), a classification of B0.2 V was given." Could HD 204 827 refer to θ Muscae? --Lambiam 03:10, 26 February 2023 (UTC)
 * Answering myself: apparently not. --Lambiam 03:14, 26 February 2023 (UTC)
 * I knew that. Theta Muscae is HD 113904. –LaundryPizza03 ( d c̄ ) 04:07, 26 February 2023 (UTC)
 * Have you checked any astronomical object databases or large astronomical object catalogs that come with some star atlases? If I wasn't so poor I'd have a copy and could check for you. Sagittarian Milky Way (talk) 14:46, 27 February 2023 (UTC)
 * Is this question about identifying Theta Muscae B, or the catalog designation of Theta Muscae? –LaundryPizza<b style="color:#b00">03</b> ( d c̄ ) 10:47, 1 March 2023 (UTC)
 * Those are ways to see if Theta Muscae B is real or citogenesis. Sagittarian Milky Way (talk) 14:21, 1 March 2023 (UTC)
 * Instances of citogenesis involve a cited source supporting a statement. In this case, we have not found a supporting source. --Lambiam 15:22, 2 March 2023 (UTC)
 * Theta Muscae B is on other websites not even just WP mirrors, if it's a hoax we're one step away. Or maybe it's real and someone just made an honest mistake. Sagittarian Milky Way (talk) 16:13, 2 March 2023 (UTC)
 * I notice the info box contains referenced characteristics for "B" (I assume Theta Muscae B). Maybe they have something? Alien878 (talk) 10:24, 3 March 2023 (UTC)
 * I also notice Double star references Theta Muscae B, but no citation... Alien878 (talk) 10:32, 3 March 2023 (UTC)

Algorithm for simulating cling and skid in billiards
So I asked a conversational search engine (as outlined on a talk page discussion regarding use of AIs) to find the algorithm for simulating cling/skid/kick in game of pool, unfortunately, it turns out that it produces good sounding but irrelevant results and even after editing, no luck for that.

However, there is a paper for different elasticity on different surfaces, which makes me curious; can Bounce Maps be changed dynamically (striking a cue ball or even a ball-to-ball collision changes the physical properties on that particular surface), and what about changing friction (which I know is responsible of throws) instead of elasticity for different surface? 2001:448A:3046:59C8:9074:C5DB:F266:4DEE (talk) 03:12, 26 February 2023 (UTC)

Soviet nukes
I think I had already asked this question some time ago, but never got an answer: at what point did Soviet nuclear weapons start being designed to be single-point safe? And in particular, was the R-13 (missile) (as deployed, for example, on the K-19 submarine) single-point safe? How about the 9M/9N-series tactical nuclear missiles (presumably the kind of warhead which was being illegally transported in the film Atomic Train, where it was incorrectly referred to as a 667-series warhead)? 2601:646:9882:46E0:99E1:8CB:A1C6:C5E (talk) 04:37, 26 February 2023 (UTC)
 * Compared with what we have on the United States, our information (at least on Wikipedia) on Soviet nuclear weapons is quite minimal. The R-13 (missile) article, for example, doesn't even discuss any details on the warhead beyond it being a single thermonuclear warhead and a really rough estimate of yield range (I realize it could be a variable yield design, but the article isn't even sure how low the yield can go). Compare that with our article on the UGM-27 Polaris, and the difference is clear. We know it carried W47 or W58 warheads, which both have their own articles, we know about challenges faced by the W47 in its single-point safety system, for some examples. With Soviet/Russian designs, either through higher levels of secrecy or lack of English language translations (or a combination of both), we don't have much public information on their warheads or their safety features. So... you probably aren't going to get the answer you want. --OuroborosCobra (talk) 21:26, 26 February 2023 (UTC)

I think there might be some info about this in the book Security Engineering, chapter 13 "Nuclear Command and Control". Scroll down to get to the pdf chapters of the 2nd edition. 2601:648:8200:990:0:0:0:BDFA (talk) 09:05, 27 February 2023 (UTC)
 * Thanks for the effort, but unfortunately there was no info about this matter in the book either -- it didn't even mention the topic of single-point safety, the only info it had about nuclear weapons had to do with the PAL links (in other words, the sole focus was on preventing unauthorized launch, not on mitigating the effect of an accidental detonation during storage or transport). 2601:646:9882:46E0:A877:D097:BE51:6D7E (talk) 07:50, 28 February 2023 (UTC)
 * Fyi, I did find a paper by Zia Mian (published by Princeton U) which said that the Soviet Union conducted "25 safety tests involving 42 weapons, between 1949 and 1990", and cited a source ("Soviet Nuclear Testing, August 29, 1949-October 24, 2990" by Robert S. Norris and William M. Arkin, in Bulletin of the Atomic Scientists, vol. 54, issue 3) https://go.gale.com/ps/i.do?id=GALE%7CA20579832&sid=googleScholar&v=2.1&it=r&linkaccess=abs&issn=00963402&p=AONE&sw=w&userGroupName=anon%7E2395a332 which supports this claim -- but the source is paywalled, so I have no way of knowing when did the actual safety tests (as opposed to full-blown detonation tests) begin, or whether any of these were actual single-point safety tests! Anyone have access to the linked article? 2601:646:9882:46E0:A877:D097:BE51:6D7E (talk) 08:53, 28 February 2023 (UTC)
 * The paper is available through Anna's Archive.- gadfium 09:09, 28 February 2023 (UTC)
 * Just checked -- still no dates regarding the safety tests (so, although this confirms that the Soviets did begin to pay attention to safety at some point, we still don't know when this happened!) 2601:646:9882:46E0:A9DB:D35F:F7B8:E80B (talk) 06:01, 3 March 2023 (UTC)