What happens to you in space? A simulation for all ages.

[Candiru]

First of all, 0K does not mean no molecular movement. Bonds will still vibrate as the lowest quantum state for a vibration is moving, not stationary. They can stop rotating and translating, but you can't stop the bond vibrations.

You only need to cool someone down to around freezing to preserve them, think about a freezer full of meat. The meat doesn't go off in the freezer for a very very long time and that is no where near 0K. The only problem is the formation of ice crystals which destroy cell membranes. The slower you freeze someone, the larger the ice crystals. Therefore if you can freeze someone fast enough you might be able to preserve them without destroying their cells from ice crystal damage.

However, defrosting them would be somewhat challenging. You would need to heat them evening throughout to quickly raise the temperature past the -10 to 0C range to avoid large ice crystals forming (Think about what happens to ice cream which is allowed to warm up to near 0C, you get large ice crystals forming by Oswald ripening.) and avoid heating them too high so they burn in places.

The logistics of freezing and re-heating someone seem pretty impossible. You could cool them to ~0.5C and keep them there for a long time then warm them up. But freezing them seems impossible.

[Fivelives]

This went way past what could be proven when we started talking about absolute zero. It seems to me though, that if all molecular movement stops, then so would the movement in the bonds between those molecules - isn't that movement caused by the orbiting electrons?

[Candiru]

Vibration energy levels for a molecular bond have energy (1/2 + n)E. At 0K the vibration will be in the ground state, n=0. This means it has energy 1/2 E. (Where E depends on the specifics of the vibrating system.) You cannot go to a lower energy state than the ground state, and at 0K everything is in the ground state.

Something like translation or rotation has energy levels which look like nE, and so when n=0 they have no energy. Bond vibrations, however, cannot go down any lower than 1/2 E.

http://en.wikipedia.org/wiki/Quantum_ha ... oscillator for more detail...

(Incidentally this ground-state energy is the reason deuterium reacts at different rates to hydrogen, as the bonds are harder to break in deuterium as they have a larger mass, which makes the vibrational energy levels smaller and so 1/2 E is less which means the energy required to break the bond is greater.)

[Fivelives]

Ha! Interestingly enough, I found an actual use for knowing the background temperature in outer space. I'm taking an online course "introduction to cultural anthropology", and one of the questions on the test we just took was this:

Specify how the study of cultural anthropology may be practical or useful knowledge? Give specific examples.

Student Response: I'm not entirely sure what you're asking for here. Jane Goodal's work with primates showed a lot of interesting parallels with human behavior, I suppose that's practical? Esoteric sciences are always difficult to draw solid, practical knowledge from. For instance, scientists have determined the background temperature in the void of outer space (2.725 degrees kelvin), but it's not exactly a practical bit of knowledge. Anthropology, especially cultural anthropology, has the added difficulty of being a very subjective science, so it's hard to determine whether or not it has practical or useful knowledge. As far as a specific example, I suppose my hypothetical study on a community's childhood obesity problem from above would work.

Score: 3/3

(the "hypothetical study on a community's childhood obesity problem from above" was something i suggested as an example of applied anthropology, which is subtly different from cultural anthropology)

[Brutalicus]

Ha! Interestingly enough, I found an actual use for knowing the background temperature in outer space. I'm taking an online course "introduction to cultural anthropology", and one of the questions on the test we just took was this:

Specify how the study of cultural anthropology may be practical or useful knowledge? Give specific examples.

Student Response: I'm not entirely sure what you're asking for here. Jane Goodal's work with primates showed a lot of interesting parallels with human behavior, I suppose that's practical? Esoteric sciences are always difficult to draw solid, practical knowledge from. For instance, scientists have determined the background temperature in the void of outer space (2.725 degrees kelvin), but it's not exactly a practical bit of knowledge. Anthropology, especially cultural anthropology, has the added difficulty of being a very subjective science, so it's hard to determine whether or not it has practical or useful knowledge. As far as a specific example, I suppose my hypothetical study on a community's childhood obesity problem from above would work.

Score: 3/3

(the "hypothetical study on a community's childhood obesity problem from above" was something i suggested as an example of applied anthropology, which is subtly different from cultural anthropology)

Epic win! Should have drawn a nice picture of the CMB for good measure:

[Fivelives]

I told my friend about that, and here was his response:

him 10:09 AM
ahh
That was your answer?
So basically by using that factoid to point out that it has not practical relevance, the student, in fact, created a practical use for it?
I'm surprised a mini-black hole didn't form on the spot and destroy the test and its insidius paradox
not practical relevance -> no practical relevance
Anyway, I'm off for lunch. Try not to destroy the universe.

[masterpoobaa]

I wanna see someone exposed to a full space vacuum within a fraction of a second.
See how long it takes for their fluids to boil and rupture to the extreme low pressures.
Exploding eyeballs would look cool!

[Arnock]

[Vrimmel]

This may or may not have anything to do with the thread... but the discussion of space "temperature" being 0K got me wondering...

Since 0K is the temperature in which cryogenics is theoretically possible, is the reason the bodies aren't preserved, because they aren't losing their heat fast enough? Obviously this is ignoring the depressurization, which I'm sure would do a number on the corpse.

The problem with cryogenics is ice. When it freezes it crystallizes and destroys body tissues.