Recent comments in /f/askscience

Dorocche t1_j5ave5l wrote

Reply to Can planetary rings be a solid surface? by barbadizzy

Rings are under a lot of pressure from all kinds of conflicting and chaotic forces. So they need to be able to move fairly fluidly.

If they melded into a single solid structure, they would immediately be ripped apart again unless they were made of a fantasy super-strong material.

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Rcomian t1_j5av747 wrote

Reply to Do other animals have dangerous pregnancies just like humans? by Level_Shift_7516

Humans are slightly special because of the baby's head, which is as big as it can be at birth. women's hips are as wide as they can really be without causing skeletal issues.

other animals haven't generally gamed their evolution in that particular way, we get more of an advantage from our brains than most. which makes our birthing process particularly traumatic for the mother.

other animals do get complications, as noted by others, but we're right on the cusp in terms of complications vs brain size optimisations.

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Dalbergia12 t1_j5auk9n wrote

Reply to Do other animals have dangerous pregnancies just like humans? by Level_Shift_7516

It absolutely happens in the wild. Since complications usually kill in the wild, the genetic predisposition to have any dangerous complications are culled out of the gene pool, so it happens less.

Many cattle and horses have very poor ability to give birth without help now. This is because they have had help for numerous generations. On cattle operations where because of geography and climate this doesn't work, ranchers are using bloodlines that have a strong ability to give birth unaided. An acquaintance developed a line of bulls whose offspring have smaller shoulders, the cows need no help almost ever. Breeding. Evolution. Darwin.

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polaroppositebear t1_j5astp3 wrote

Reply to Can planetary rings be a solid surface? by barbadizzy

No. What you are seeing is many small pieces of dust and debris which from a distance seem dense and or solid. Take clouds for example. Before we knew about the precipitation process, we thought clouds could possibly hold structures.

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[deleted] t1_j5a8fxi wrote

Reply to How does lightning illuminate the sky? by AverageMan282

Thanks to gas excitations, both crackling lightning and brilliantly colored exploding fireworks can send chills up your spine and cause your heart to beat faster.

While the vivid white light we associate with lightning is an example of incandescence, with a temperature in the order of 30,000 K, its colors also stem from gas excitations - light emitted through the excitation of gas molecules in the atmosphere. Gas excitations are a form of luminescence, photons of light being emitted as excited electrons drop back to their initial energy state. Unlike incandescence, luminescence may occur at low temperatures.

Likewise, pyrotechnic experts use incandescence to create brilliant white fireworks, but rely on the phenomenon of gas excitation to create the dance of colors we expect from fireworks. In addition, neon, mercury, and sodium lights take advantage of gas excitations.

https://www.webexhibits.org/causesofcolor/4.html

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