Why is Space a Vacuum

Phoenix-D · #1 January 28th, 2004, 05:35 AM

Space is a vaccum because there is little to nothing -there-. Vaccum is just lack of pressure. Nothing there, nothing to exert pressure..

Given enough time and nothing external to stop it, gas will expand to fill any available space. In the case of your oxygen bottle, that amounts to the entire UNIVERSE. So the pressure is very low even when there is something there.

narf poit chez BOOM · #2 January 28th, 2004, 05:35 AM

i think what you are asking is, does the air exert presure on the container or does the vacuum actually suck?

i would say that the air exerts presure becuase there is 'nothing' in space to suck, although i have wondered about this to. i mean, how come nobody seems to wonder about this?

so, Phoenix-D, why does it exert pressure?

[ January 28, 2004, 03:37: Message edited by: narf poit chez BOOM ]

Phoenix-D · #3 January 28th, 2004, 05:36 AM

The air exerts the pressure. Or tries to.

narf poit chez BOOM · #4 January 28th, 2004, 05:39 AM

Atrocities · #5 January 28th, 2004, 05:40 AM

Since space is so expansive, endless really, we could never hope to fill it with anything that we can breath.

So if oxygen occurs on our planet, whey does it now occur naturally in space?

How do we over come the obvious danagers that make space space? I have read about things like cosmic winds, megnetic storms and microscopic particle currents and such, so space is not devoid of gasses and such. Just look at a nebula. They are not dispersed into nothingness to fill the void, so if a nebula can exsist as a nebula, a collection of gasses, why can there not be a oxygen Nebula?

Phoenix-D · #6 January 28th, 2004, 05:48 AM

There could be an oxygen nebula. Of course, the pressure there would still be far too low to support human life, to say nothing of the tempature.

Oxygen occurs naturally wherever it collects due to gravity, or where it is created by fusion reactions (or supernova)

EDIT: air exerts the pressure because its a bunch of N2 and O2 molecules bouncing around. Those hitting the container are what creates the effect we call pressure.

[ January 28, 2004, 03:49: Message edited by: Phoenix-D ]

Fyron · #7 January 28th, 2004, 05:49 AM

When molecules move and collide with something, they exert force on it, transfering some kinetic energy. This is what pressure is, a measure of the average force that the matter is exerting upon a surface, an object, a probe, etc.

[ January 28, 2004, 03:49: Message edited by: Imperator Fyron ]