Wikipedia:Reference desk/Archives/Science/2022 October 18

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October 18

Turtle shells

[1] Is that true about turtle shells? All of them have that 13/28 pattern, and is there some plausible evolutionary explanation connecting that with the lunar cycle? Thanks. 2602:24A:DE47:B8E0:1B43:29FD:A863:33CA (talk) 14:48, 18 October 2022 (UTC)

I had a look at som turtle shells on Google and whilst I was able to confirm the 13 in the centre I was not able to get anything like a solid 28 for the ones on the edge, that was for the turtles I found that looked like that. The 13 seemed to be formed by three central hexagonal ones in a line in the centre with the other ten filling around them in a straightforward manner. So the 13 seems to be for good structural reasons and the 28 - well it just doesn't seem to be true. Or perhaps they weren't good at counting. So I think I can safely dismiss that article as magical thinking. NadVolum (talk) 15:39, 18 October 2022 (UTC)

It's also not true when you look at the other side of the proposition (all other calendars do not have the 13/28 pattern). The Thai lunar calendar (and I'm sure man]] y others) does not match that model. Not to mention that the lunar cycle isn't 28 days. And the year is not 364 (or 365 days if we include the one day of rest the picture speaks of). --User:Khajidha (talk) (contributions) 17:38, 18 October 2022 (UTC)

Our Turtle shell article says that most turtles and tortoises do indeed have the same number of scutes (external plates), but "Some species of turtles have some extra bones called mesoplastra, which are located between the carapace and plastron in the bridge area". Alansplodge (talk) 20:12, 18 October 2022 (UTC)

• Even if all turtle shells have some kind of 13/28 pattern, that doesn't mean that all times that 13 or 28 appear in other places in nature has any kind of correlation. This is a classic cum hoc ergo propter hoc-type BAD thinking. Unless someone can show a mechanistic causal link between two phenomena, you can quite safely ignore any kind of claims along these lines. Vigorous application of Hitchens's razor is a must in these kinds of questions. For those asserting a causal link between two coincidental things; if they present no evidence of a link, you can dismiss the claim immediately. The coincidence is not evidence of itself; which is to say the fact that two numbers match is not evidence that the phenomena producing those numbers are connected. Or in our case, merely because the number of plates in a turtle's shell happen to match something about lunar and/or solar cycles is not evidence in itself that those two phenomena are related. --Jayron32 20:31, 18 October 2022 (UTC)

  See also strong law of small numbers. —Tamfang (talk) 03:18, 22 October 2022 (UTC)

At risk of stating the obvious, a random Twitter user is never a reliable source for anything. Shantavira|^{feed me} 08:21, 19 October 2022 (UTC)

Thanks all. Yeah the claim doesn't seem that well supported, though the cautions against it aren't that convincing either. It is perfectly fine to observe something interesting, like the long necks on giraffes, and then look for explanations like "they evolved so the giraffes could eat high foliage". There are lots of biological phenomena marked by the annual cycle (rings on trees), the lunar cycle (menses in mammals), and the diurnal cycle (circadian rhythms). The biological phenomema tend to not be exactly synchronized to the astronomical ones (e.g. human circadian rhythms are often 25-26 hours instead of 24), so the 364 vs 365 day discrepancy doesn't seem like a showstopper. Therefore it sounded plausible to me that there could be some known scientific theory relating the turtle shells to those cycles. But it doesn't sound like there is one. 2602:24A:DE47:B8E0:1B43:29FD:A863:33CA (talk) 19:16, 19 October 2022 (UTC)

It's c. 25 (sometimes 50) hours when the experiment didn't fail from unintentional latching onto experimenter communication times etc. If instead of living in a lightproof, soundproof, vibration-proof constant weather box sleeping and waking whenever you want not knowing what time it was the experimenters let in full sunlight the first 4 hours awake and made them use candles in pitch dark the rest of the day most humans would be less than 24 hours. Maybe the early birds would even reach 23. Sagittarian Milky Way (talk) 20:02, 19 October 2022 (UTC)

it seems unlikely that the moon wouldn't have all sorts of influence on the Earth and its inhabitants. However, with respect to your "28" you don't even have correlation with the moon's 29.5 day cycle, let alone causality. ---- — Preceding unsigned comment added by 37.166.10.12 (talk • contribs) 21:36, 19 October 2022 (UTC)