xXDWARFAREXx wrote...
Lareit wrote...
FACT#2. When a human is exposed to the vacuum of space their body undergoes decompression. The first 7 seconds into the decompression the subject has full control of their motor functions and higher cognitive reasoning. After words as their blood begins to expand and boil away their higher reasoning decays untill they eventually pass out at the 30 second mark.
Your fact #2 is a bit off as I understand it. Your skin and arteries/veins/capillaries are a good enough container that your blood doesn't boil. It's the sustained lack of oxygenated blood to the brain that drops the higher reasoning and passing out.
I think the whole "blood boiling" thing got started because the drop in pressure
will cause blood gases to precipitate. "Boiling" isn't a bad
qualitative way to describe a bunch of gas bubbles forming in your blood and organs, so my guess is someone used it for that purpose at some point and it got taken too literally and passed on into urban legend.
This NASA page provides a good description of what happens, and adds to the whole "trauma" side of the discussion:
Various minor problems (sunburn, possibly "the bends", certainly some [mild, reversible, painless] swelling of skin and underlying tissue) start after ten seconds or so. At some point you lose
consciousness from lack of oxygen. Injuries accumulate. After perhaps one or two minutes, you're dying. The limits are not really known.
You do not explode and your blood does not boil because of the containing effect of your skin and circulatory system. You do not instantly freeze because, although the space environment is typically very cold, heat does not transfer away from a body quickly. Loss of consciousness occurs only after the body has depleted the supply of oxygen in the blood. If your skin is exposed to direct sunlight without any protection from its intense ultraviolet radiation, you can get a very bad sunburn.
At NASA's Manned Spacecraft Center (now renamed Johnson Space Center) we had a test subject accidentally exposed to a near vacuum (less than 1 psi) in an incident involving a leaking space suit in a vacuum chamber back in '65. He remained conscious for about 14 seconds, which is about the time it takes for O2 deprived blood to go from the lungs to the brain. The suit probably did not reach a hard vacuum, and we began repressurizing the chamber within 15 seconds. The subject regained consciousness at around 15,000 feet equivalent altitude. The subject later reported that he could feel and hear the air leaking out, and his last conscious memory was of the water on his tongue beginning to boil.
I don't know about you, but that sounds rather unpleasant. Now add in the rest of the circumstances Shep was in and I think "traumatic" is rather apt.
MOST TRAUMATIC THING EVAR!? No, but definitely far beyond the "Well, that kinda sucked. Boy, I sure am glad it didn't last that long, at least as far as some couch-sitting outside observer reminiscing about falling off the monkey bars at recess one time is concerned" level.
Modifié par didymos1120, 20 février 2010 - 11:02 .