Why would your blood boil if you were exposed to the vacuum of space?

Answer 1

It wouldn't.

According to NASA:

"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."

Answer 2

Your body won't blow up. Your blood won't boil, either.
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 negligible.

Answer 3

The boiling point ttemperature of any liquid is decreased as pressure decreases. In a vacuum, liquids will boil at lower temperature, so perhaps blood boils in space due to body temperature: 98.6 degrees...but if its in our bodies, then it shouldnt be affected by the vacuum, only if it's out of the body? I never thought about it before, quite interesting....

Answer 4

There is such a thing as "explosive decompression," but that merely refers to the sudden loss of pressure in an air- or spacecraft, not the effect on the occupants. Though your chances of surviving such an experience are slim, your body would not explode (although see below). In fact, if you were able to scramble to safety quickly enough (as the helmetless astronaut did in the famous scene from 2001: A Space Odyssey), you might emerge virtually unscathed.

To be sure, there are a few troublemakers who will give Cecil an argument on this. Some flight surgeons at NASA, for instance, say death in a vacuum would be almost instantaneous. They offer the following Technicolor scenario: your blood would boil, your eyeballs would explode, and your lungs would turn to red slush.

But the medical literature suggests this view is exaggerated. For one thing, I have never seen anything indicating your eyeballs would explode (although your eardrumms might burst). It's true that in the absence of ambient pressure your blood and other bodily fluids would boil, in the sense that they would turn to vapor. But that's not as drastic as it sounds. Your soft tissues would swell markedly, but they'd return to normal if you were recompressed within a short time.

It's conceivable your lungs might rupture, since in a vacuum the air in them would greatly expand. But experience suggests this is rare even if decompression is extremely rapid. The chances are much greater if your windpipe is closed, making it impossible for the expanding air to escape.

Death would not be instantaneous. It's believed you'd have 10-15 seconds of "useful consciousness" and it'd be several minutes before you'd die. If you were rescued within that time there's a decent chance you'd survive. Research with chimps and monkeys suggests that if you were exposed to a virtual vacuum for less than 90-120 seconds you might not suffer any permanent damage.

That said, there are circumstances involving explosive decompression in which your body might be torn to bits. This would result not from the exposure to a vacuum per se but from injuries caused by the accompanying air blast. I have here a medical journal article about a case of explosive decompression that killed four divers. (They went from high pressure to normal rather than normal to vacuum, but same idea.)

The bodies of three of the dead men were outwardly normal. The fourth man, however, was forced through a narrow hatch by the rush of escaping air and his body, to be blunt, was reduced to pot roast. Naturally, the authors of the article felt obliged to include pictures, including a close-up of what was left of the face. You might show them to your bozo friends next time they're chattering about blown up bodies.

Answer 5

Blood, like any other liquid, has a boiling point.
This point does not only depends on temperature, but also on PRESSURE.
Water, for example, is solid at 0 degC and 1013.25mBar pressure (standard atmosphere). It becomes vapour at 100degC at the same pressure.
If you go high on a mountain, the water will start boiling at a lower temperature (i.e. 90 degC), because the pressure at the top of a mountain is lower than at sea level.
If you go into space, where the pressure is ZERO mBars, all liquids instantly "boil" (evaporates).

Answer 6

When a liquid in normal pressure of 14 PSI, is exposed to a Vacuum, All the air trapped in it will expand and become bubbles of air. These air bubbles would make it look like blood was boiling.
this happen in a Hydraulic Pump inlet if it become restricted and causes to much of a vacuum. Called cavitation in pump systems.

Answer 7

This problem is associated with the rapid decrease of pressure outside the body which is more commonly experienced by deep-sea divers. The blood contains dissolved nitrogen, a gas which comprises most the the atmosphere. When rapid depressurization occurs, the nitrogen will bubble out of the blood in effort to equalize the pressure difference. In space, there's nothing to counteract this process.

Answer 8

Your blood WOULDN'T boil in space, at least not in the conventional sense. It may vaporise due to lack of pressure if you cut yourself and bled out into space, but it would not reach a boiling temperature.

However, if the blood remained inside the blood vessels, it would not even do that!

Answer 9

The boiling point of any liquid, in a vaccum, drops. Space is one powerful vaccum! Any change in temperature will upset the molecules very violently and rapidly.

Answer 10

Have you ever seen those pens that have water in a vaccum ball, and you touch it and it boils?

There is no pressure so gas expands, also way divers can't come up fast.