what happens to the human body in a vacuum?

Answer 1

There are a number of things about being in space, in a vacuum, which could cause harm to the human body.

You wouldn't want to hold your breath. This would cause lung damage. You would probably remain conscious for several seconds, until the blood without oxygen reaches your brain.
It would be pretty darn cold, but the human body doesn't lose heat that fast, so you'd have a little time before you froze to death. It's possible you could have some problems with your eardrums, including a rupture, but maybe not. It would be worse if you had a cold, and were stuffy headed, with no way for the pressure to equalize.

You could get a bad sunburn, and you might actually swell some, but not to Arnold Schwarzenegger, "Total Recall" proportions. The "bends" are also possible, just like a diver who surfaces too quickly.

While your own normal blood pressure will keep your blood from boiling, the saliva in your mouth could very well begin to do so. In 1965, while performing tests at the NASA facility now known as Johnson Space Center a subject was accidentally exposed to a near vacuum (less than 1 psi) when his space suit leaked while in a vacuum chamber. He did not pass out for about 14 seconds, by which time unoxygenated blood had reached his brain. Technicians began to repressurize the chamber within 15 seconds and he regained consciousness at around the equivalent of 15,000 feet of altitude. He later said that his last conscious memory was of the water on his tongue beginning to boil.

The human body is amazingly resilient. The worst problem would be lack of oxygen, not lack of pressure in the vacuum. If returned to a normal atmosphere fairly quickly, you would survive with few if any irreversible injuries.

There have actually been cases of parts of astronauts bodies being exposed to vacuum, when suits were damaged. The results were considerable .

Answer 2

Do you mean exposed to the vacuum of space without life support? If so, here is the definitive answer:

To experience the vacuum is to die, but not quite in the grisly manner portrayed in the movies Total Recall and Outland. The truth of the matter seems to be closer to what Stanley Kubrik had in mind in 2001: A Space Odyssey.

According to the 1966 edition of the McGraw/Hill Encyclopedia of Space, when animals are subjected to explosive decompression to a vacuum-like state, they do not suddenly balloon-up or have their eyes pop out of their heads. It is, in fact, virtually impossible to compress or expand organic tissues in this way. Instead, death arises from the response of the free gasses trapped within the tissues.

If decompression takes 1/2 second or longer, even lung tissue remains intact. When the ambient pressure falls below 47 mm of mercury (similar to the pressure at the surface of Mars), the water inside all tissues passes into a vapor state beginning at the skin surface. This causes the collapse of surface cells and the loss of huge amounts of body heat via evaporation. After six seconds, the process of cell collapse involves the heart and lungs causing circulatory interruption, followed by acute anoxia, convulsions and the relaxation of the bowel muscles. After 15 seconds, mental confusion sets-in, and after 20 seconds you become unconscious. You can survive this for about 80 seconds if a pressure higher than about 47 mm mercury is then reestablished, otherwise, you turn into freeze-dried dead meat on a stick.

There you go . . have fun!

Answer 3

Astro's answer is based on the assumption that you're suddenly transported into outer space. However, I'll assume that the situation is still on earth and a person finds himself inside a large sealed plastic box that has no air/atmosphere in it.

Since that person now has no air to breathe, he will quickly lose consciousness due to a lack of oxygen and will die if the air isn't restored immediately.

As for the body itself, the vacuum creates a situation where there is no asmospheric pressure. In the absence of that, I imagine that any gases within the body would tend to expand.

Answer 4

Two things, really.

First, our bodies are like a balloon. The only thing which forces a balloon to hold it's shape is the fact that the pressure on the inside of the balloon is equal in measure to the pressure outside, minus the force of the rubber pressing in on itself. Put a balloon in a vacuum and it'll pop... very quickly.

Have fun imagining that in the human body.

Also, since we are 80% water, this is the second thing.

If you haven't put water in a vacuum before, it begins to "boil". The dissolved gasses in the water escape. The dissolved gasses (oxygen, nitrogen, carbon dioxide) begin to escape our blood, rupturing our vessels, causing our eyes to burst and otherwise ruining our day.

Our - I'm saying our... ugh... you sicko!

Answer 5

Are you referring to something like a Black Hole interaction? If anything like that should happen all life on Earth including THE Earth will be sucked into the Hole like a vacuum.

Answer 6

I don't know. I can never even get my foot past the floor attachment.

Answer 7

It's not very pretty. YOU DIE!!!