Originally posted by Gazrok
Within seconds, less than 30, you'd go BOOM! Simple as that...
(as I understand it...) The aforementioned issue of your blood expanding due to
lack of pressure in the vacuum... Not a pleasant way to go I'd bet....
Like Kano said, jp's link explains it well:
How long can a human live unprotected in space?
If you don't try to hold your breath, exposure to space for half a minute or so is unlikely to produce permanent injury. Holding your breath is
likely to damage your lungs, something scuba divers have to watch out for when ascending, and you'll have eardrum trouble if your Eustachian tubes
are badly plugged up, but theory predicts -- and animal experiments confirm -- that otherwise, exposure to vacuum causes no immediate injury. You do
not explode. Your blood does not boil. You do not freeze. You do not instantly lose consciousness.
...
The reason that a human does not burst is that our skin has some strength. For instance compressed oxygen in a steel tank may be at several hundreds
times the pressure of the air outside and the strength of the steel keeps the cylinder from breaking. Although our skin is not steel, it still is
strong enough to keep our bodies from bursting in space.
Think about it, pressure difference is only one bar.
And when divers go down every ten meters (30 feet) means 1 bar more external pressure to which your body adapts. In 30 meter total pressure is 4 bar
and your body adapts to that but do you think that diver would explode if he would make rapid ascend to surface where external pressure is 1 bar and
his internal pressure of his body 4 bars?
(meaning 3 bar pressure difference)