The_Flurr

The_Flurr t1_jdrcp2x wrote

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The_Flurr t1_jdqqenn wrote

Sweat regulates temperature, it doesn't actively cool the body to lower than the temperature of the sweat. Your skin and sweat equalise in temperature until the sweat evaporates or is wicked away.

It's the same in all liquid cooling, the substance being cooled cannot be cooled beneath the temperature of the coolant.

Assuke the water in the space suit would be relatively consistent throughout its volume. The drop in pressure from being exposed to hard vacuum drastically decreases the amount of energy it needs to boil. So for each water molecule, some of its thermal energy will essentially be used to change state. It won't suck energy out of neighbouring particles to do so unless they are significantly hotter.

If the water were in a sealed chamber you might observe what you described, because the now cooler vapour would be contained with any remnants of liquid water. In open space however, the vapor would disperse too quickly for the vapor to take any meaningful amount of heat away.

I say this ironically while writing a report on the nitrogen cooled cryostat I made for a uni project.

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The_Flurr t1_jdozfqb wrote

The energy required for the water to boil would come from the thermal energy of the water itself.

This is just not how fluids work. Boiling fluids do not suck the thermal energy from surrounding fluids to do so, that would defy rules of entropy.

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The_Flurr t1_jdmsa1k wrote

That's not what happens in real life. Vacuum will fuck with your bodily fluids, causing bruising and bleeding, but it won't explode out of you. The human body is actually pretty good at containing pressure.

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The_Flurr t1_jdms1tv wrote

The water wouldn't freeze very quickly at all.

Vacuum isn't cold, it has an absence of temperature. There is nothing for the water to transfer its heat to directly, so it would only cool by radiation, which is slow.

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The_Flurr t1_jdmrtvi wrote

Explosive decompression really isn't a thing. You need pressure differentials much higher than one atm to cause that sort of force.

Air isn't sucked out of you instantaneously, that's not how fluid dynamics work, you'd need a much higher differential for it.

Estimates generally give about 15-30 seconds before loss of consciousness, depending on how oxygenated your blood is.

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The_Flurr t1_jdmrdc5 wrote

You generally have about three minutes before brain damage due to oxygen deprivation.

You'll also not lose consciousness that quickly. Most estimates give up to 30 seconds, which will depend on how oxygenated your blood is at the time.

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The_Flurr t1_jdmhl51 wrote

In an absolute emergency, you could probably get away with it for a few seconds. Just long enough to get some of the water out.

It takes several minutes for hard vacuum to actually kill you.

That's assuming it's even possible for astronauts to open their EVA suits while outside.

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