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mcabeeaug20 t1_j12wzlf wrote

Reply to comment by Scott_Abrams in Could being submersed in a sealed tank of fluid help humans survive heavy G acceleration in outer space? by cheeze_whiz_shampoo

Have you seen the old movie, "The Abyss" ? This is exactly what they do to the guy- not to withstand G-force, but the immense pressure from a Super deep dive. Great movie for the late 80's. Still love it!

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th3d3wd3r t1_j13g8sn wrote

That's a cool scene when he drops the mouse in. But yeah, there are breathable fluid, but our lungs aren't able to deal with the viscosity. That alone causes traumatic injury. Also, the movie "Event Horizon", they go in tanks of fluid.

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gargravarr2112 t1_j13mbw3 wrote

IIRC in the Abyss, the breathing fluid was real and the rat was actually breathing it on film (the scene got censored for the UK release due to perceived animal cruelty). Bud, however, wore a helmet full of coloured water and held his breath.

In Event Horizon, the crew still breathe gas through masks. The medic mentions in the opening scene: "When the ion drive engages, we'll be pulling about 20 Gs. Without a tank, the force would liquefy your skeleton." Another comment notes that breathing gas is still viable to about 20G, above which fluid breathing would be required.

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InvisibleBlueRobot t1_j14hcca wrote

It was real for the mouse, in real life military tests the fluid is too heavy and it damages human lungs to the point of incurable issues. So we need a little work. Something lighter and easier to move in and out of the lungs but provides the same benefit.

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anormalgeek t1_j15u81z wrote

Isn't it being "heavy" directly related to how well it handles the pressure though? Like if it's light enough that our lungs aren't damaged, then it's light enough to have the same issues are breathable air.

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glaucusb t1_j13pil9 wrote

It is not exactly the reason but still related to the pressure. In SCUB or surface-supplied diving, the air that the diver breath has the same pressure as the level that the diver is, called ambient pressure. That means when the diver is let's say in 20 metres, they consume 3 times more air in quantity (but volume is the same). This has three consequences as the dive is deeper. (1) It requires way more and bigger SCUBA tanks (there are also closed system devices that cycles gases that are not used called rebreathers to address this issue but they are a bit risky) or stronger compressors (in surface supplied diving). (2) oxygen is toxic over 0.8atm (there is also time as a factor, here is an oxygen toxicity table so we need to decrease the percentage of oxygen and increase other (inert) gases. (3) inert gases do dissolve more in the body tissues and blood during compression (when their pressure increases) and does not leave body as fast so create bubbles that results in clogging arterials and damaging tissues and organs (which we call decompression sickness). We have a solution to all these problems in deep diving what we call saturation diving. You let divers to dive in chambers and let them decompress in these pressurised chambers for weeks after the dive on the vessels. In scuba diving, we do stops in ascending.

In Abyss, they were supposed to dive to a depth that was not done before so, it would require a lot of pressure and inert gas. Also it would be quite difficult to arrange the mix since the percentage of oxygen in the mix should be quite low to prevent oxygen toxicity. Instead, they use a liquid that they can control the mix of gases in it. They also do not need to use huge amount of gas since the diver does not need to breath in ambient temperature.

One last fact: the scene that a mouse is put into liquid and it is breathing inside liquid is a real scene without any visual effects (link here). They used a liquid that can carry enough oxygen and submerged a mouse into it.

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