BBC Focus Magazine

[Dark One]

We often see the gristly effects of decompression in sci fi films, but I just wonder what the actual effects of sudden decompression would actually be. Are we talking bursty eyeballs? Or just a few minutes of suffocation?

[M Paul Lloyd]

Ah yes, the old exploding head thing, It's yet another myth from the world of Hollywood, with the exception of films based on the work of the Late Arthur C Clarke, specifically 2001 a Space Odyssey and its not so well known sequel.

The thing is atmospheric pressure is relatively low at around 14.7 Pounds per Square Inch at sea level (even lower in the Space Shuttle spacesuits which was just 4.3 PSI of pure oxygen) so the step to a total lack of pressure is hardly that great.
Mind you if you took a deep sea diver straight from the depths of the ocean into orbit I wouldn't like to predict the outcome.
However based on sea level pressure as used on board the Shuttle and presumably the ISS if you try holding your breath your lungs will feel as if they are going to explode and keeping your eyes tight shut would certainly be good idea. Apparently it is possible to hold your breath for up to two minutes or more (with practice) but the lack of pressure would allow your body fluids to boil which would make it all a lot less pleasant and have serious consequences (the decompression sickness suffered by deep sea divers comes to mind here) if not addressed very quickly. Oh and the contents of your stomach may well become a bit of a problem...............

[Shadowwolf]

Don't forget that it's cold out there, very, very cold.

Like Mr M illustrates you're going to have problems but nothing is going to explode or pop in a spectacular gory fashion. A very brief excursion sans protective suit could be potentially survivable though certainly not recommended. As I just saw Sunshine I know that a particular scene has exactly this scenario of unprotected short hop and they stick a bit closer to reality, though the worst effects Mr Evans character suffers seems to be frostbite related which may be downplaying it somewhat. The poor sap that bounced off into the void ran out of air but also seemed to die from being turned into a human popsicle more than anything else, mind you I'm unsure if the body would freeze solid so fast.

...specifically 2001 a Space Odyssey and its not so well known sequel.

2010, not a bad movie either.

[Isee]

I thought the decompression was due to nitrogen or something in the lungs, which is not there in big amounts if we are decompressing from the sea level pressure. So in my understanding, you won't get the bends going from 1atm to 0 (but you will get other adverse effects)

This reminded me of a test pilot who tool the MiG-31 aircraft to above its' service ceiling and the cockpit glass came off due to lack of outside pressure (internal artificial pressure popped it open basically, with no outside pressure to counteract it) and the only reason this man survived is that he had a g-suit on. He recalled hsi wife asking him to switch off the lights before he would udnerss before sleeping because the man resembled a walking bruise...

[M Paul Lloyd]

by Isee
I thought the decompression was due to nitrogen or something in the lungs,

Its actually nitrogen in the blood stream and general body fluids which, as they expand, rather than dissolve, become horribly painful and potentially life threatening unless addressed very quickly by re-pressurization. So yes it effects the lungs but everywhere else too.

by Shadowwolf
Don't forget that it's cold out there, very, very cold.

True but you would only lose body heat by radiation so it would take quite a while, certainly longer than it would take to suffocate or indeed notice a bit of a chill going on.