Why is Space a Vacuum

[geoschmo]

Originally posted by narf poit chez BOOM:
in one of the short stories i read, people evacuated from one ship in space to another after expelling air from their lungs. no-one was in space more than 30 seconds. feasible?

side note: the book mentioned a technique where you breath heavily a few times then expell the air from your lungs. i tried this and was able to hold my breath for 20 seconds at the start and after some practice, 35 seconds. it really is easier, despite sounding counter-productive.

Basically this is feasible, as long as someone is there to pull in the unconcious people. The technique divers use doesn't really help in vacuum. A diver will expell all the air they can, but there will still be enough oxygen there to keep you concious. And as you surface the lower pressure causes the air in your lungs to expand, which satisfys your instinct to inhale. If you don't expell the air in your lungs it will still expand, but cause damage. That's why you can't hold your breath in vaccum too, cause the air will expand and damage your lungs. The difference is expelling your lungs in a vacuum leaves you without enough oxygen to keep you concious for more then a few seconds.

So 30 seconds wont kill you or cause any permenant damage. But it will incapacitate you. You'll need someone there to pull you in.