Silurian hypothesis

[Maximilian Hohmann]

(04-24-2019 03:14 PM)Leviset Wrote:  Are you saying Deep Sea (which my son when he was 5 continually called them dipsy divers) Divers don’t need to be encased in an atmospheric pressure suit kept at a 1 atmosphere pressure when they go down?

No. They usually wear "soft" but watertight immersion suits whose internal pressure is the same as the outside pressure. To avoid the necessity to decompress after each dive they live inside pressure chambers when not in the water for up to one month at a time.
There are also so called "Atmospheric Diving Suits" (https://en.wikipedia.org/wiki/Atmospheric_diving_suit) which are small one-man submarines that keep the internal pressure at 1 atmosphere all the time. But they are so expensive that only the US Navy can afford some...

(04-24-2019 03:14 PM)Leviset Wrote:  Why is one of the best ‘games’ that Oceanographers like to play is that of decorating a polystyrene cup, lowering it over the side on a long string down near to the ocean bottom so that when it’s hauled back up its now the size of a thimble covered with now miniature drawings? Presumably it’s been ‘crushed’ under the pressure or is it the terminology that you object to?

Yes, exactly. This is possible bacuse the polystyrene consists mostly of air (or maybe nitrogen) bubbles surrounded by very thin plastic. When they get compressed by the water the plastic ruptures, the gas is released and the cup will not re-inflate when brought back to the surface.
The neoprene suits worn by recrational divers are similar. There are made from small gas bubbles surrounded by rubber. In the depth the bubbles get compressed and an 8mm neoprene suit (I chose that example because mine is like that) will only be something like 3mm thick 40m below the surcace (thereby losing most of it's thermal insulation where you need it most and also losing much of it's buoyancy, thereby necessitating the use of a "BCD" or buoyancy control device, an inflatable vest). But the rubber is elastic and does not burst, so when coming back to the surface the suit will be again as thick as it was before.

(04-24-2019 03:14 PM)Leviset Wrote:  Should I have said if humans even could stand on the surface of Jupiter (without a suit) they wouldn’t be ‘crushed’ by the atmospheric pressure but rather they would shrink, collapse, deflate, flatten, dry up, shrivel, wilt, wither, abate, decrease, diminish, dwindle, lessen, recede or any permutation or any combination of these?

Nothing of that will happen. When you descend to the surface of Jupiter (or Venus, wearing appropriate heat protection) and give the gas filled cavities inside your body (which are the lungs and the sinuses and some other bits of the respiratory system) enough time to fill with breathable gas with the same pressure as outside then you will stay exactly as before. 99 Percent of the body is either bone or some kind of liquid (or jelly or similar) which are not compressible.
The only thing to avoid is rapid compression and rapid decompression as this will damage the lungs and hollows inside one's head, causing a "barotrauma" (https://en.wikipedia.org/wiki/Barotrauma). But crushing? No.

Regards
Max