4 ms·

If they don't have compressible gasses in them, I don't see why they shouldn't. There would be gas dissolved in the water inside them that would have to be de

If they don't have compressible gasses in them, I don't see why they shouldn't. There would be gas dissolved in the water inside them that would have to be dealt with I suppose. But the water itself is damn near in-compressible. The volume of water inside them down there would be the same up here. Decompression explosions like the Byford Dolphin accident happen when compressible gasses are involved. Compressed gasses are like springs that store huge amounts of energy. This is why pneumatics have very energetic failure modes while hydraulics are relatively safe (injection wounds and oil fires notwithstanding)

ncmncm 8y ago
Bi-layer membranes, such as cell membranes and walls of organelles, are squeezed together, so may be thinner and stiffer. It would not be surprising if some species could not adapt to lower pressure, just as we are ill-adapted to vacuum.
- darkpuma 8y ago
  I'm not a biologist but I believe the pressures should be equalized inside and out. The problem humans have with pressure is mostly related to humans being filled with gasses. Contrary to popular belief, humans don't explode when exposed to a vacuum. The fleshy bits hold together just fine, but trying to hold your breath would rupture your lungs, forcing you to exhale, which causes you to asphyxiate. There have been a few cases where isolated body parts were depressurized, which caused painful swelling but no permanent damage. I think it's likely that swelling occurred because the rest of the body was still pressurized, in effect squeezing the body out into the unpressurized portion of the suit. This is similar to one of the failure modes of old style diving bell helmets where depressurization of the helmet could force a diver's body into the helmet.
  - chmod775 8y ago
    NASA/USAF put (whole) dogs in a vacuum: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19660005052.pdf https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/196600... The paper is pretty short read. They reference another study that was conducted with primates, but I'm not able to find it at this moment. Here's the part about primates: "After decompression to approximately 1 mm. Hg absolute, the squirrel monkeys appeared to lose consciousness sooner than the dogs. As with dogs, they had both tonic and clonic seizures shortly after unconsciousness and this progressed to flaccid paralysis. Subcutaneous emphysema and swelling occurred, but was not as marked. During and following recompression to ground level, the monkeys recovered similarly but seemed to exhibit staggering and disorientation for a longer period. Two monkeys died as a result of these low pressure exposures, while no dogs died from exposures that were less than 120 seconds. [...]" It's under "Observations made on small primates" on page 7.
    - darkpuma 8y ago
      NASA once accidentally depressurized a man while testing space suits in a vacuum chamber. He lost consciousness in less than 15 seconds, but fully recovered after depressurization. He reported feeling his saliva boil which is... exciting. https://www.youtube.com/watch?v=KO8L9tKR4CY https://www.youtube.com/watch?v=KO8L9tKR4CY http://www.spacesafetymagazine.com/aerospace-engineering/space-suit-design/early-spacesuit-vacuum-test-wrong/ http://www.spacesafetymagazine.com/aerospace-engineering/spa... During Project Excelsior, Joseph Kittinger's right hand was depressurized at 100,000 feet and swelled up, but he was ultimately unharmed. https://en.wikipedia.org/wiki/Project_Excelsior#Test_jumps https://en.wikipedia.org/wiki/Project_Excelsior#Test_jumps
  - ncmncm 8y ago
    It is meaningless to conclude anything from "equalized pressure" beyond that nothing is changing in size. To conclude from animals recovering from pressure changes that the high or low pressure is harmless is equally absurd. Leave them at the given pressure and they die. Humans under high pressure, exposed to nitrogen, or even a normal amount of oxygen, soon die. Not from gases exploding, but from different physical and chemical behavior of substances under high pressure. Under high enough pressure, at normal temperature, gases become liquid. A cell membrane under pressure, after pressure has equalized, does experience the same pressure on both sides. But because cell membranes have two or more layers, the stuff in the middle gets squeezed. Is the pressure in the middle equal to that on either side? Of course, otherwise it would continue getting thinner. Does that have anything to do with the topic? Nothing whatsoever.

ncmncm 8y ago

Bi-layer membranes, such as cell membranes and walls of organelles, are squeezed together, so may be thinner and stiffer. It would not be surprising if some species could not adapt to lower pressure, just as we are ill-adapted to vacuum.

darkpuma 8y ago
I'm not a biologist but I believe the pressures should be equalized inside and out. The problem humans have with pressure is mostly related to humans being filled with gasses. Contrary to popular belief, humans don't explode when exposed to a vacuum. The fleshy bits hold together just fine, but trying to hold your breath would rupture your lungs, forcing you to exhale, which causes you to asphyxiate. There have been a few cases where isolated body parts were depressurized, which caused painful swelling but no permanent damage. I think it's likely that swelling occurred because the rest of the body was still pressurized, in effect squeezing the body out into the unpressurized portion of the suit. This is similar to one of the failure modes of old style diving bell helmets where depressurization of the helmet could force a diver's body into the helmet.
- chmod775 8y ago
  NASA/USAF put (whole) dogs in a vacuum: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19660005052.pdf https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/196600... The paper is pretty short read. They reference another study that was conducted with primates, but I'm not able to find it at this moment. Here's the part about primates: "After decompression to approximately 1 mm. Hg absolute, the squirrel monkeys appeared to lose consciousness sooner than the dogs. As with dogs, they had both tonic and clonic seizures shortly after unconsciousness and this progressed to flaccid paralysis. Subcutaneous emphysema and swelling occurred, but was not as marked. During and following recompression to ground level, the monkeys recovered similarly but seemed to exhibit staggering and disorientation for a longer period. Two monkeys died as a result of these low pressure exposures, while no dogs died from exposures that were less than 120 seconds. [...]" It's under "Observations made on small primates" on page 7.
  - darkpuma 8y ago
    NASA once accidentally depressurized a man while testing space suits in a vacuum chamber. He lost consciousness in less than 15 seconds, but fully recovered after depressurization. He reported feeling his saliva boil which is... exciting. https://www.youtube.com/watch?v=KO8L9tKR4CY https://www.youtube.com/watch?v=KO8L9tKR4CY http://www.spacesafetymagazine.com/aerospace-engineering/space-suit-design/early-spacesuit-vacuum-test-wrong/ http://www.spacesafetymagazine.com/aerospace-engineering/spa... During Project Excelsior, Joseph Kittinger's right hand was depressurized at 100,000 feet and swelled up, but he was ultimately unharmed. https://en.wikipedia.org/wiki/Project_Excelsior#Test_jumps https://en.wikipedia.org/wiki/Project_Excelsior#Test_jumps
- ncmncm 8y ago
  It is meaningless to conclude anything from "equalized pressure" beyond that nothing is changing in size. To conclude from animals recovering from pressure changes that the high or low pressure is harmless is equally absurd. Leave them at the given pressure and they die. Humans under high pressure, exposed to nitrogen, or even a normal amount of oxygen, soon die. Not from gases exploding, but from different physical and chemical behavior of substances under high pressure. Under high enough pressure, at normal temperature, gases become liquid. A cell membrane under pressure, after pressure has equalized, does experience the same pressure on both sides. But because cell membranes have two or more layers, the stuff in the middle gets squeezed. Is the pressure in the middle equal to that on either side? Of course, otherwise it would continue getting thinner. Does that have anything to do with the topic? Nothing whatsoever.