Wikipedia:Reference desk/Archives/Science/2024 May 15

= May 15 =

They see me rollin', they hatin...
Question for you guys. Is there any animal whose primary method of locomotion is curling into a ball and rolling head over heels to get around? Rather than running or walking. Because I think some woodlice do it (faster for them to roll then run), but I'm not 100% sure. Iloveparrots (talk) 03:04, 15 May 2024 (UTC)
 * Do fictional animals count? --136.54.106.120 (talk) 03:33, 15 May 2024 (UTC)
 * Terrestrial locomotion may be of interest. --136.54.106.120 (talk) 03:38, 15 May 2024 (UTC)
 * I don't see how that could ever be a primary means of locomotion, but see also Category:Rolling animals. Shantavira|feed me 08:37, 15 May 2024 (UTC)
 * Hedgehogs do it to escape from predators when threatened. 2601:646:8082:BA0:BC05:6EA8:F933:9E6D (talk) 10:43, 15 May 2024 (UTC)
 * Hedgehogs roll up for protection, not for locomotion. (Ditto for the woodlice mentioned by the OP). Iapetus (talk) 11:57, 15 May 2024 (UTC)
 * I don't think I've ever seen a hedgehog roll outside of a video game. But then again, I've only ever seen hedgehogs in real life about three times. Iloveparrots (talk) 22:58, 15 May 2024 (UTC)
 * Hedgehogs do not purposely roll when in a defensive ball. They "huff", which makes them bounce, forcing their quills into whatever is attacking them. That bounce could cause a roll, but it isn't on purpose. 75.136.148.8 (talk) 13:40, 16 May 2024 (UTC)
 * See Rotating locomotion in living systems. 2605:B100:34D:46C3:61A4:6B17:A082:3780 (talk) 12:27, 15 May 2024 (UTC)
 * I have encountered assertions that Giant pandas, when sitting in a bamboo thicket on a slope, will sometimes roll a short distance rather than get up and walk, but this would need confirmation from a reliable source, and in any case would not be a primary means of locomotion. {The poster formerly known as 87.81.230.195} 94.2.67.173 (talk) 19:48, 15 May 2024 (UTC)
 * A giant panda is rolling head first in this video: Panda Discovers Something Interesting. They roll about a lot too, for various reasons. Modocc (talk) 23:30, 15 May 2024 (UTC)

What's the max depth of the Baltic, Black and Azov brim?
The depth where it stops being connected to the World Ocean 50% of the time (connected only by seepage through porous solids like silt not counting as connected). As the brim can erode, shift if the water's removed, be a V-notch in a ridge etc and even if it's dredged wide, straight and flat it might not be legal to lightly touch the silt so this might not round to the same number of feet as the deepest draft ship that's allowed at least 50% of the Metonic cycle, or how much sea level would have to drop to make it a lake 50% of the time. Also what would the depth be if the strait bottom wasn't landscaped? The Turkish Straits are pretty deep by ship standards maybe they aren't landscaped? Sagittarian Milky Way (talk) 18:05, 15 May 2024 (UTC)


 * They wouldn't need to be "landscaped", the Bosphorous is typically about 60 m deep with a 40 m sill towards its southern end, although the Asian side of the strait at that point is somewhat shallower (about 27 m) - see Siddall et al. (2004). Mikenorton (talk) 19:11, 15 May 2024 (UTC)
 * Right I didn't think they would. Unless the depth of the rim's now artificial by more than a foot due to sinking accidents(s), full or partial intentional blockages or explosion(s) (possibly to clear some of the previous)? Or maybe it's still the natural rock or sediment accumulation-erosion surface? I don't know if the Baltic and Azov brim are unaffected by human landscaping. Sagittarian Milky Way (talk) 20:16, 15 May 2024 (UTC)