3 ms·

Gas-filled cavities in the body instantly compress. So this means that your lungs, stomach, etc. instantly get crushed, rupturing in the process. Depending on c

by dvt 3y ago

Gas-filled cavities in the body instantly compress. So this means that your lungs, stomach, etc. instantly get crushed, rupturing in the process. Depending on circumference, depth, etc., the hull itself moves at speeds of ~1000+ mph towards itself, crushing everything inside in less than 100 milliseconds. Someone linked a great safety video of what happens under a pressure column (not gore)[1]. Though as some people mentioned, since carbon fiber was used here, it's more likely that the hull shattered, essentially turning it into shrapnel. I think this depends on the exact proportion of the life support gases they are using, but, due to the relation P ∝ T, the gas inside the submersible can ignite (like an engine piston essentially), turning all organic matter to ash instantly. [1] https://www.youtube.com/watch?v=Zz95_VvTxZM https://www.youtube.com/watch?v=Zz95_VvTxZM

pests 3y ago
> turning all organic matter to ash Is this actually true? I see it being repeated everywhere but there is a lot of mass in a human body. Can 100 milliseconds of "ignition" (as you put it) really burn off all of that?
- maverwa 3y ago
  I am no expert on any of this but was curious. So I entered some guesstimates in online calculators. Assuming they were at 12,500 ft / 3810m we get a pressure down there of 5546 PSI / 382 Bar. Compressing the air in the cabin from roughly atmospheric pressure to 382 Bar would heat it to above 1300°C, or 1600°F. As far as I understand, in milliseconds. That’s a lot of heat energy. The water around them will absorb some of that, but they‘d be toast.
  - Auracle 3y ago
    That doesn’t seem nearly hot enough to burn bodies before the water takes the place of all that hot air. Do the bodies themselves get hot from being compressed? I’d assume largely no with our water content.
    - colechristensen 3y ago
      Think of it like a shock wave passing through the cabin and everything in it in time measured in milliseconds. Everything gets very hot basically instantly on the other side of that wave. Water less than gas, I’m too lazy to figure out what would be expected to exactly happen to water, but it would definitely be between getting hot enough to kill and disassociating to elemental hydrogen and oxygen gas. The question is what does a 6000 psi step function look like as it propagates through water. Having gotten hit on the head in a low speed car accident I wouldn’t worry at all about the suffering through the actual implosion. The speed of the shock wave would be much faster than nerves conduct information.
- 4ad 3y ago
  No, it is not true at all. Heat conduction velocity is independent of the temperature gradient. It would only affect a very shallow layer of the skin. The gas can heat to thousands of degrees but there isn't much energy in it. It wouldn't do much damage by itself. The sudden change in pressure causes the majority of the destructions through purely mechanical effects.
  - f38zf5vdt 3y ago
    A truly HN discussion -- what percentage of the occupants would be ash and what percentage of the occupants would be molecularly sheared viscous people fluid that rapidly disperses. The oxygen tank would rupture and provide an ignition source too.
maronato 3y ago
One comment regarding the video you shared. The tank shown implodes due to the atmospheric pressure, since they imploded it by creating a vacuum inside. The sub, on the other hand, would be under something like 350x the atmospheric pressure, so we can expect its implosion to be orders of magnitude more violent.

by dvt 3y ago

pests 3y ago

> turning all organic matter to ash Is this actually true? I see it being repeated everywhere but there is a lot of mass in a human body. Can 100 milliseconds of "ignition" (as you put it) really burn off all of that?

maverwa 3y ago
I am no expert on any of this but was curious. So I entered some guesstimates in online calculators. Assuming they were at 12,500 ft / 3810m we get a pressure down there of 5546 PSI / 382 Bar. Compressing the air in the cabin from roughly atmospheric pressure to 382 Bar would heat it to above 1300°C, or 1600°F. As far as I understand, in milliseconds. That’s a lot of heat energy. The water around them will absorb some of that, but they‘d be toast.
- Auracle 3y ago
  That doesn’t seem nearly hot enough to burn bodies before the water takes the place of all that hot air. Do the bodies themselves get hot from being compressed? I’d assume largely no with our water content.
  - colechristensen 3y ago
    Think of it like a shock wave passing through the cabin and everything in it in time measured in milliseconds. Everything gets very hot basically instantly on the other side of that wave. Water less than gas, I’m too lazy to figure out what would be expected to exactly happen to water, but it would definitely be between getting hot enough to kill and disassociating to elemental hydrogen and oxygen gas. The question is what does a 6000 psi step function look like as it propagates through water. Having gotten hit on the head in a low speed car accident I wouldn’t worry at all about the suffering through the actual implosion. The speed of the shock wave would be much faster than nerves conduct information.
4ad 3y ago
No, it is not true at all. Heat conduction velocity is independent of the temperature gradient. It would only affect a very shallow layer of the skin. The gas can heat to thousands of degrees but there isn't much energy in it. It wouldn't do much damage by itself. The sudden change in pressure causes the majority of the destructions through purely mechanical effects.
- f38zf5vdt 3y ago
  A truly HN discussion -- what percentage of the occupants would be ash and what percentage of the occupants would be molecularly sheared viscous people fluid that rapidly disperses. The oxygen tank would rupture and provide an ignition source too.

maronato 3y ago

One comment regarding the video you shared. The tank shown implodes due to the atmospheric pressure, since they imploded it by creating a vacuum inside. The sub, on the other hand, would be under something like 350x the atmospheric pressure, so we can expect its implosion to be orders of magnitude more violent.