Wikipedia:Reference desk/Archives/Science/2022 March 30

= March 30 =

Cat Rection to A-Minor Chord
Are there any references about cat reactions to certain chords? There is a cat here that drops low, lays her ears back, and starts chirping when a A-minor chord is played, but does not react to any other chord. 97.82.165.112 (talk) 18:02, 30 March 2022 (UTC)
 * I'm not aware that cats have perfect pitch, but one never knows. There are a few studies listed here that discuss cat response to music in general, but I can find nothing on specific chords.  I will note that individual cat psychology is likely to be as individualized as humans are; as such the fact that your cat reacts in a specific way to a specific stimulus is certainly no different than a specific human who may have a reaction to a stimulus, whether a specific sound, taste, odor, etc.  Just as a person may have a unique reaction to a specific stimulus that other people do not, that doesn't mean that humans in general react that way.  -- Jayron 32 18:26, 30 March 2022 (UTC)

Plourdosteidae
I recently made an article for Compagopiscis, and was going to add a taxobox (someone else ended up doing it). When I got to the family part, I was stuck. One website said that Compagopiscis was in Plourdosteidae. I looked at the page for Plourdosteus, and it said it was in Panxiosteidae. So I looked it up and found that Plourdosteidae was an invalid taxon and that Plourdosteus was, in fact, in Panxiosteidae. But another website said that Compagopiscis was not in Panxiosteidae.

So basically, what I'm asking is-

What family is Compagopiscis in?

(Somebody else added a taxobox and put it as Plourdosteidae, but how can it be a valid taxon if its namesake isn't even in it?)

Asparagusus (talk) 18:25, 30 March 2022 (UTC)


 * You might find Wikipedia talk:WikiProject Palaeontology a better location for asking this question. Mikenorton (talk) 20:57, 30 March 2022 (UTC)


 * Not a resolution but a piece of the puzzle. The main contribution of this article is to argue that fossil remains of Compagopiscis croucheri and Gogopiscis gracilis actually represent a single species occupying the monospecific genus Compagopiscis. While it places the genus in the infraorder Brachythoraci, it does not identify a family. However, the authors do write that the presence of eight morphological characteristics in the compagopiscids, which they proceed to specify, can be used to easily separate C. croucheri from the superficially similar Plourdosteidae. So, in the judgement of the authors, assigning the genus to the Plourdosteidae is wrong. It should be understood that in general the systematic taxonomy of palaeontological species is often conjectural and may be subject to reordering as new evidence is found in the geological record. --Lambiam 22:25, 30 March 2022 (UTC)
 * This article positions Compagopiscis in the superfamily Incisoscutoidea, together with Incisoscutum and the Camuropiscidae. (Currently, Wikipedia treats Incisoscutoidea and Camuropiscidae as sister families in the superfamily Coccosteoidea.)  --Lambiam 10:47, 1 April 2022 (UTC)

Dissimilar woods
I've been following the reconstruction of Tally Ho (yacht), and they seem to combine very different kinds of timber without any problem or even thought. For dissimilar metals, especially in a marine environment, this would, of course, lead to galvanic corrosion and probably reduce the structure to different kinds of rust quickly. Are there any similar constraints for wood? --Stephan Schulz (talk) 19:51, 30 March 2022 (UTC)
 * Yes, it's well worth a watch! YouTube link nagualdesign 14:12, 31 March 2022 (UTC)
 * According to a woodworker at Elite Custom Woodworks in Greenville, SC, once woods are dried, you can and should mix them. Having different woods makes custom woodworking appear much higher quality. If you do this when the wood is not fully cured (which I take to mean fully dry), it can eventually warp and cause problems. But, there is no reaction between one wood and another. Then, according to a professor of dendrology at Clemson, all tree wood, regardless of species, are almost completely cellulose and hemicellulose. Using that information, we have a book, Handbook of Wood Chemistry and Wood Composites by Roger Rowell that states the same thing. Tree wood is just cellulose and hemicellulose with minor deposits of sugar, starch, and pectin. He references Wood and Cellulose Science by Alfred Stamm, who goes on to state that the primary difference between woods is the accessibility of the cellulose. Higher accessibility leads to faster rotting from water and easier access for parasites. If that doesn't help, I can look further. I didn't know much about wood chemistry before I started calling around. 97.82.165.112 (talk) 21:00, 30 March 2022 (UTC)
 * Serious warping may also occur with constructions using just one kind of timber, if it is insufficiently dried. Ideally, it should not be 100% dry; it should instead match the average humidity of its future environment, so that it will remain in a relatively stable equilibrium with that environment. --Lambiam 23:02, 30 March 2022 (UTC)
 * See Church of St Mary and All Saints, Chesterfield. Martin of Sheffield (talk) 09:33, 31 March 2022 (UTC)
 * Wow. "lack of skilled workers [...]; the use of insufficient cross bracing and 'green timber' [...] the 17th-century addition of 33 tons of lead sheeting covering the spire, resting on 14th-century bracing not designed to carry such weight". I always liked wood as a material, and this is one example where so much went wrong, and it still holds up (mostly) under pressure. I wonder what will happen in 2318, when they put 33 tons of weight on something "not designed to carry that load" today. If anything from today is even standing in 300 years.... --Stephan Schulz (talk) 10:05, 31 March 2022 (UTC)
 * Here's a building made from 10,000 different kinds of wood. (I only found this because Lambiam used the term "neo-grotesque" on the language desk, so I searched for a modernist grotto to see what kind of writing might be on it.) Card Zero  (talk) 13:58, 31 March 2022 (UTC)
 * "...match the average humidity of its future environment...". Tally Ho is (or will eventually be again) an ocean-going yacht; should it therefore be constructed of very wet timber?
 * I also note (as an avid follower of Leo's videos) that he takes great pains to avoid allowing fresh water to touch his timber, but is unconcerned about the quantities of salt water in which it will inevitably be soaked. Does that have a bearing on how dry his timber should be? --Verbarson talkedits 18:12, 31 March 2022 (UTC)
 * I expect he intends to use yacht varnish before committing it to the deep. Alansplodge (talk) 20:49, 31 March 2022 (UTC)

Any credible source on Polonium-210 production, export figures?
Poisoning of Alexander Litvinenko has these two not clearly sourced sentences: "About 85 grams (450,000 Ci) are produced by Russia annually for research and industrial purposes. According to Sergei Kiriyenko, the head of Russia's state atomic energy agency, RosAtom, around 0.8 grams per year is exported to U.S. companies through a single authorized supplier.". If I got it rigth, the source "Supplementary Report by Norman David Dombey" suggests some confusion between 8g/month and 0.8g/month, where the larger figure wasn't/isn't much credible, but was reported all over the place (e.g. Polonium, $22.50 Plus Tax, where Kiriyenko is mentioned). Polonium-210 currently cites a source for 8g/month (not sure if exports increased that much in these years). To add to the confusion 0.8g/month is not that far from 8g/year. Also I'm not sure if the same confusion applies to the production figures or if there is some other article worth double-checking. 109.119.244.192 (talk) 22:28, 30 March 2022 (UTC)
 * This should be the mentioned Reuters article and this (archive) the one from Rossiyskaya Gazeta. Reuters talks about Sergey Kiriyenko, while RG features Ilkaev and mentions some previous talk about 8 g/month, so it's possible that Reuters and others refer to some other article. Kiriyenko is't exactly a physicist. Both seem to be more about production than export or export to the US. 109.119.244.192 (talk) 02:46, 31 March 2022 (UTC)
 * Actually I found this citing Interfax instead of RG (Kiriyenko, 8g/month, all export to the US, published before Reuters). The previously linked RG is later than both, so it kind of make sense (but is mentioned in the "Supplementary Report" as being from october, not from december). I still have no idea what would be a credible export amount. 109.119.244.192 (talk) 04:15, 31 March 2022 (UTC)
 * Ransac talks about 100 preprations "B" monthly. 8g/100*4500 Ci/g gives 360 Ci per preparation. In 1978 the limit for transport in type A packages was 200 Ci, type B packages would still allow more . Assuming 0.1 Ci per static eliminator, 8g would be enough for 8g*4500Ci/g÷0.1Ci=360,000 units. 176.247.189.17 (talk) 07:33, 2 April 2022 (UTC)
 * Looks like Kirienko was correcting a previous statement about 8g/year, so it was really quite messy.176.247.143.235 (talk) 15:24, 3 April 2022 (UTC)