If I take off my helmet, will my head explode?

Question

I'm on Mars.

Answer 1

The ambient pressure on mars is around 0.7 kPa, or about 0.006 Earth atmosphere.

This is well below the "triple point" of water. One might prematurely conclude, that any liquid water in your body would simultaneously freeze and flash into vapor, like what happens when you discharge a CO2 fire extinguisher......(If you've ever used one of those things...... )
http://boomeria.org/chemlectures/textass2/fig17-9.jpg

However, In practice this is not the case. The Idea that a human would explode in space is based on a naive knowledge of physics and human physiology.

Experiments on humans and animals indicate that humans can survive a vacuum around a minute with few ill effects, and still be revived after several minutes.

The skin and blood vessels are very tough and elastic, blood pressure alone (~12-14 kPa) is usually enough to prevent boiling, except perhaps in superficial veins and capillaries. The skin, head, or body does not explode, but the difference in pressure tends to cause minor to moderate swelling (edema) which in turn squeezes shut arteries and veins in the skin and extremities. If any of the blood does boil, instead of bursting the vessels, it forms small bubbles(embolisms) that block blood flow. This is similar to what happens during "the bends."

Freezing or frostbite is unlikely. Vacuum is a very good insulator (e.g. a thermos bottle...) Spacewalking astronauts have to wear liquid cooled underwear to keep from overheating.

The danger of vacuum is asphyxiation. Loss pf pressure causes oxygen to leave the blood rapidly through the lungs. After about 10 or 15 seconds, the oxygen deprived blood reaches the brain, and you lose consciousness. However, as I said, life threatening damage to the lungs, brain, heart, and circulatory system might take several minutes. No one really knows how long a person could survive a near vacuum and still be revived.

Note: the difference in pressure on mars would make taking off your helmet impossible, until you'd decompressed your entire suit.....

Probably more than you wanted to know....
~W.O.M.B.A.T.

Answer 2

You will find out everything you need to know by watching Arnold Schwerzenegger in "Total Recall". It has scenes of mars and exploding heads.

Here are some clips:
http://www.youtube.com/watch?v=rbdP4TBopYU
http://www.youtube.com/watch?v=V17duGlHEYY

Answer 3

Not if you're in a properly pressurized construct. Or if the oxygen atmosphere making machines have started to work, Arnold.

Answer 4

your head will explode to millions pieces thats make your friend got head picking to do.....also remind your friend to brought paper bag just in case

Answer 5

Yes.

Answer 6

if u take off the helmet, you're ******

Answer 7

Yes it will. And if I take mine off underwater, it will implode.