No space travel movie would be complete without someone getting shoved out of an airlock and dying horribly. This handy guide will help you ascertain how fake these airlockings really are - and get over your fear of sliding doors.
Let's start by dispelling some myths. Here are the ways that, cinematic evidence to the contrary, you won't die in vacuum.
1. Exploding eyeballs.
Technically, this is not fatal. However, I'd like to think that when faced with the prospect of having their eyeballs explode like Arnold Schwarzenegger's in Total Recall, most people would stab their own fingers through their chests and puncture their hearts. Go on. It's the more merciful option. Treat yourself.
Fortunately, eyeballs wouldn't explode in a vacuum, any more than they'd cave in under 33 feet of water. The body wouldn't swell up and explode like a marshmallow in a microwave, either.
There's just not enough pressure inside of us to blow us up. I know. It disappoints me, too.
2. Freezing to death.
I applaud the optimism and sunny outlook of people who think they would survive in a vacuum long enough to freeze to death, but this is probably the least credible of the options. For one thing, space isn't freezing. Space isn't any temperature. Temperature is the measurement of the movement of atoms. There aren't many atoms in a vacuum, so technically there can't be a temperature. This is the physicist's version of ‘What is the sound of one hand clapping?'
Unless you were shoved out an airlock near the sun, your major change of temperature would be the heat escaping from your own body. Eventually enough heat would be lost to freeze you to death, but you're much more likely to freeze to death if you get drunk and pass out in the open on New Years or swim too long in a chilly river. And, speaking of liquids . . .
3. Boiling Blood.
I hate to take away the poetry of this image, but the truth must be told. Your blood wouldn't boil in a vacuum. Well, technically it would, if it were in a bowl. Water stays in its liquid form in part due to atmospheric pressure. In a vacuum it would boil and turn into water vapor.
Fortunately, when you get shoved out an airlock, most of your bodily liquids aren't in a vacuum. They're in you. Skin, membrane, cell walls and blood vessels exert their own pressure on the liquids inside the human body. There are points in a body that will lose liquid quickly, such as the eyes, mouth, nose and, ah, lower-body orifices. Some liquids will make their way towards the surface of the body through cell walls, causing further damage, but there's no boiling blood.
4. Lung Shredding
Yes, that's as painful and messy as it sounds. It's high up on the list because it could actually happen. Remember point four, in which I described how blood vessels and other bodily tissues exert pressure on the various expandable things inside the body? There are certain tissues that are more delicate than others. The alveoli, tiny air sacs in the lungs, are an example of more delicate tissue. They also happen to hold gas that expands quite a bit when external pressure is dropped.
Because a vacuum does not carry sound very well, you would not be able to hear the many, many alveoli in your lungs pop like bubble wrap under a child's fingers, but don't tell me that you wouldn't imagine it.
Fortunately, this only happens if you hold your breath, forcing the air to rupture the lungs rather than come rushing painlessly out through the mouth. The temptation is there to save your air, since you won't be getting any more. Resist that temptation. Besides, you probably won't die from -
This seems like the one that would get you, doesn't it? If there's one thing we know about people, it's that they need air, and if there's one thing we know about deep space, it's that it doesn't have air. Mystery solved, right? That pretty much wraps it up.
Sadly, you won't last long enough to asphyxiate.
What would actually get you?
Yes, the thing that could kill you in your sleep, jogging, or just on your couch eating cheetos, would also be what is most likely to get you in outer space.
In experiments conducted by scientists who will probably be re-incarnated as those women who wear bikinis and get in cages for PETA stunts, animals were exposed to different pressure levels. In vacuums, many of them began having heart problems within a minute. Once a heart stops, the pressure inside of small blood vessels drops, allowing the vacuum to damage them faster. Once the tissue dissolves and the liquid is exposed, well, that's when the blood boiling happens. Fortunately, one of the first results of exposure to a vacuum is loss of consciousness. It takes only 10-15 seconds. You won't want to be awake for the rest.
A body in a vacuum isn't a dramatic explosion, but a slow taking-apart. Damage accumulates and structure deteriorates, just like it would in an abandoned house. Maybe this is the most horrifying idea of all, although admittedly it's not cinematic. We aren't fragile creatures, shattered instantly under the wrong conditions. We're just part of the world, breaking down, or being torn down, no faster or slower than anything else.