Having seen a demonstration using a glass of water under a bell jar with a vacuum pump attached, I can safely say that water boils unit it has lost enough heat to freeze. In the demonstration, a vacuum of 1 x 10 (-4)torr (about 10 -(7) atmospheric, took about 10 minutes. With a sudden exposure to 1 x 10 (-7)torr (near space), the same thing would happen, but the violence of the boiling process would atomize the liquid, so you’d get (yellow, in the case of urine) snow. After freezing, the ice would subliminate until it reached ambient temperature, a few degrees above absolute zero in near solar space, damn near in deep space. I’m not using references, so the numbers are from memory and could be off by a factor of 10, and pardon any errors.
Hi and welcome to the SDMB! It helps if you include a link to the column, which is Would a glass of water in space freeze or boil?
Factor of ten, factor of a hundred, no big deal, right :)? Snow should have an albedo similar to that of the Earth, and it’s in the same environment as the Earth, so the equilibrium temperature it would reach should also be comparable to Earth, or a few hundred Kelvins.
When you can see a clear and visible disk of a star, it’s pretty safe to say that your location does not qualify as “deep space”, at least for purposes of temperature.
I should have looked it up. O.K, water would boil, freeze, and subliminate until it’s all gone.
Factor of 10 or 100 is in reference to pressure, which on earth is 10 to the +3, near space is about 10 to the -6 to -8, so -7 =/- a factor of 10.
The corresponding saturation temp for water at 10 -7 is -119c or 154k, but while looking this up, I discovered I was talking through my pants, 'cause apparently there’s more going on. I couldn’t find a reference to the pressure outside the atmosphere and inside the earth’s orbit, but I remember an instructor referring to the 10 -8 for outer solar system experiments. …So, I have no idea what the pressure outside the shuttle is (thus, I have no idea what the ambient temp would be in the absense[or presence for that matter] of the sun’s light. I think it’s safe to say an ice cube would last a while in the earths shadow (but I have no idea if it’s month or millenia)
By the way,I discovered that deep space has a temperature of 2.73k, try working that into a conversation.
Still… I saw the water freeze, and it got smaller and colder as the experiment progressed–so there.
So… did anyone else have to look up ALBEDO?
(I won’t try that again.)
Although it won’t have a radioactive core heating it up.
True, but the internal heating of the Earth has little effect on the temperature of the surface.
And I’ve never had trouble working the microwave background temperature into conversation, but then, most of the people I converse with are other physicists. 