empty out water into the space

[ispom]

in a German forum
http://www.physikerboard.de/htopic,3724,.html

there was not to receive any explanation to the question:

Assumed I empty out a bucket of water from a spaceship into the space,
will this water form a globe(or any other shape) or will it explode immediately ?

was that experiment taken already by the NASA or by the Russian astronauts?

[Lee]

I only understand one word on that site - wasser.... and 1 and Liter, and Hallo! sorry.....

I know it forms a globe inside a spacecraft with an atmosphere, in a vacuum, unsure - I think it sort of boils/freezes at the same time.....

[xelasnave]

Lee get the fish to translate .
What an interesting proposition .
First how to get the water to stay in the bucket needs to be addressed, and even at the low temp could it boil.. boiling is a relationship of pressure and temp... mmm now this is interesting. But to freeze it will give up heat so maybe that will cause it to boil.The absence of presure will enable it to boil at a low temp... I hope there is a conclusive answer I have enough mystery in my life. The action of tipping it out would possibly cause it to distribute because of the energy imparted ...so off the top of my head it would form many small spheres which would because of their size freeze fast but being smaller then would have opportunity to boil quicker..??? ok hold all calls this is important .. The fish and I will have a look at the site .
alex

[ispom]

I think:
Whatever shape the water will take it would quickly fixed as ice ,
but than it will very fast vaporize,
how fast, so fast that is looks like an explosion?
But all that should also depend on the temperature,
will say, how the water is heated by sunshine if it is exposed for it.

[[1ponders] (Paul)]

In the vacuum of space water can only have two forms, ice or gas. This is how a comet works. The ice of the cometry bodies sublimates directly from ice to gas as it nears the sun and gains energy. There is no water phase.

In the situation you are suggestion, the water would not explode (infact a human body would not swell up and explode either, that is simply hollywood mythology). The most likely scenario is that the liquid will start to evaporate while the temperature drops. It will then freeze at 0 deg, but continue to sublimate away until there is no ice left. This is assuming that the ice is exposed to sunlight. If it is shaded it will probably remain as ice indefinately. Just like a comet.

[White Rabbit]

Ok, so what happens to a human body when exposed to a vacume?

[[1ponders] (Paul)]

Nothing. Apart from you'd die. Your exposed wet surfaces, mouth, eyes, nasal passages etc would dry out and you'd want to keep a tight clench on your sphincter and yes the air would be sucked from your lungs if you opened your mouth, but that is all. Eventually though you would end up freeze dried as the water in your blood froze and over a period of time sublimated away. You would likely get initial bleeding from various openings with the blood gradually freeze drying, but there is no way you would blow up like a balloon or "explosively decompress". There just isn't enough free gas in your body, plus your skin is too strong to expand or explode like that.

Here is an easy way to test what is going on. If you get a long glass tube and cap one end (like a large version of a test tube), fill it full of water in a tub of water, and invert it so that all the water falls to the bottom of the tube. What do you have in the space at the top. There is no air, there is no water, it must be very close to a vacuum. (This would work better and you would get a stronger vacuum if you used a heavier liquid like mercury but much more dangerous).

Now get something like a small grape that will fit up the tube (or a dead guppie or gold fish if you have one) and place it in the tube. Now with your finger/hand over the end of the tube to prevent the grape from falling out, but still letting the water drain out, raise the tube until it is just in the water and there is next to no water in the tube. Now cap the tube. You have a very good approximation of a vacuum. What has happened to the grape (analogous to the human body)? Nothing. It hasn't swollen up like a balloon, it hasn't exploded and it hasn't leaked it's juices all over the place. If it was as cold in the tube as it is in space then the grape would freeze. And that is all.

Hope that helps

[ispom]

my American friend BooBoo gave me the following statement:

The normal surface tension of a body of water is far too weak to keep it cohesive. What you end up with is a large cloud of tiny ice crystals. Another way to look at it is that the water freezes, but does it so quickly that it literally shatters into millions of particles.

[Lee]

Originally Posted by [1ponders]

Nothing. Apart from you'd die. Your exposed wet surfaces, mouth, eyes, nasal passages etc would dry out and you'd want to keep a tight clench on your sphincter and yes the air would be sucked from your lungs if you opened your mouth, but that is all.

True in regard to dissolved gases in your fluids, and trapped gas in spaces - but you need to think of your body water too - at 63000 feet above sea level, the vapour pressure of water hits 1 atm at the 37 deg C mark - so water boils at 37 deg (or lower as you climb) - bad news for us warm blooded buggers who are literally full of water! This is called ebullism - experiments have been done with monkeys years ago, exposing them to vacuum conditions, and then recompressing them, apparently they seemed near unscathed if they weren't exposed too long....

[[1ponders] (Paul)]

at 63000 feet above sea level, the vapour pressure of water crosses the 37 deg C mark - so water boils at 37 deg or lower

True, for exposed water, but your body doesnt lose pressure like that. As long as your skin remains intake it acts to keep the blood pressurized. If it couldn't do this then under normal conditions we would explode simply from arterial pressure being generated from the heart.

[Lee]

A lot of vessels will rupture under that pressure though..... it is a concern if someones blood pressure is 200mmHg - water boiling exposes them to 760mmHg....

[xelasnave]

What would happen to a ballon filled with water in space?
alex

[Lee]

This is one in zero gravity, but under some atmospheric pressure....
http://video.google.com/videoplay?do...84492638545730

I think given the lack of pressure, the water would boil, expanding the balloon until it burst.....

[[1ponders] (Paul)]

Yes a balloon would burst, and in a human body you would get some surface capillaries rupturing, particularly in nasal passages and in the eyes and possibly sub-dermal veins. But for deeper vessels to burst they would have to expand first and the body's skin and muscles would help to prevent veins from bursting and the thick walls of arteries would remain intact.

[[1ponders] (Paul)]

I did a quick search and found this on the nasa site.

http://imagine.gsfc.nasa.gov/docs/as...rs/970603.html

There are plenty of others.

[[1ponders] (Paul)]

and here

http://en.wikipedia.org/wiki/Human_adaptation_to_space

[Mikezoom]

Does not the same thing happen when they purge human watse into space? (Just a guess)

Mike.