• RadioRat (he/they)@beehaw.org
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      1 year ago

      Not actually correct in this case. Hypoxia is only painless if oxygen is displaced with an inert gas like nitrogen. Our bodies detect low oxygen indirectly via chemoreceptors that detect the increase in blood acidity (respiratory acidosis) induced by high carbon dioxide (hypercapnia).

      As humans breathe in a sealed environment, oxygen is replaced with CO2. Hypercapnia is what causes the panic and pain of drowning prior to inhalation of water. Consciousness is lost mere seconds after water inhalation.

      Drowning and hypercapnic asphyxiation are essentially the same experience in terms of suffering.

      Secondary outcomes and resuscitation are a different story, but are obviously not applicable here.

      • Obi@sopuli.xyz
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        1 year ago

        I think I read something about the sub having a CO2 scrubber which would mean their bodies wouldn’t feel the lack of oxygen due to what you explained, but I know nothing about this.

        • RadioRat (he/they)@beehaw.org
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          1 year ago

          This is a good question! Not sure which precise units they had and in what quantity, but given the size of the Titan (no way they can support liquid regenerative system with their size and energy reserve constraints), they would have had canister containing solid CO2 adsorbent with a fan (example).

          Without the fan, it’s not going to be very effective since CO2 has to actually pass over the solid. Passive diffusion is not going to move the same volume of CO2 over the solid even if the solid was removed from the housing. Even if they didn’t run out of battery, The solid has a maximum capacity - about 7.5 kg for the unit linked above. Even with reserve capacity, an average human exhales ~0.97 kg of CO2 per day.

          O2 to CO2 exchange via respiration is mole for mole (you do lose a little mass in carbon and water just by breathing!). Atmospheric CO2 is 0.041% (410 ppm) and O2 is a hair under 21% and that’s the standard to which life support systems are held. Humans lose consciousness at around 3.7% oxygen, but experience hypercapnia at >6% CO2. (Physiology nerds - I converted from the partial pressures in mmHg to % of 1 atm for comprehension)

          So in this hypothetical scenario, hypercapnia would definitely precede loss of consciousness due to anoxia.

    • aport@programming.dev
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      1 year ago

      Nobody drowned, they were instantaneously squished under the massive pressure of the deep sea

    • Recant@beehaw.org
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      1 year ago

      Well the fact that they are saying it was a catastrophic implosion leads to the thought that it was crushed in a very short amount of time maybe even a few seconds so I doubt they had time to drown.

      • Fauxreigner@beehaw.org
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        1 year ago

        It’s not a few seconds, it’s a very small fraction of a second. The Thresher imploded in 1/20th of a second at 730 meters. We don’t know for sure how far down Titan was when it imploded, but based on the time they lost signal, I’m guessing around 3500 meters, so we’re talking about 4-5 times as much force. Plus the hull was made of extremely brittle carbon fiber, so it wouldn’t buckle at all, it would just collapse all at once. It’s hard to overstate how much force we’re talking about; at that depth, it’s about equivalent to building the Empire State building out of lead and sitting it on top of the ship with no other supports.

        It’s not just that they didn’t have time to drown; it would have imploded so quickly that they would have been dead before their brains even had time to process that something was happening.

    • elizardbeth@beehaw.org
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      1 year ago

      They would have died (or at the very least, lost consciousness) from the pressure long before they drown.