energy from the sun in space? (not via solar cells)

[tlowe90]

OK, i had this idea where you could make power in space from air and the suns heating properties. forgive me if this idea is completely irrational as i have no schooling in any form of this sort of thing. so oxygen on earth is heated by the sun but takes energy to remove it... would it be possible to use the fact that space is cold to exploit the sun heating then space its-self cooling liquid oxygen as a renewable recourse? kinda how nuclear reactors heat up water to steam but using the sun and space. once again i'm not stating that this WOULD work but asking someone who could tell me. (i swear i'm not one of those "free energy" quacks on youtube XD)

[Matokage]

Maybe This

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

Somekind of Advanced Peltier Cells array could do the trick.

[phoenix_ca]

Space doesn't actually do all that great a job at cooling things. It takes other atoms to carry away thermal energy, and there just aren't all that many atoms in space. It's full of nothing.

As a roughly analogous example/explanation, the ISS uses photovoltaic radiators to a manage heat. They can be thought of as, roughly, photovoltaic solar cells, but in reverse. (Radiating photons isn't an issue in space. Radiating thermal energy is.)

[Ydoow]

I'm not too sure I follow what you're saying, but I'd like to double up on what pheonix_ca said.

Space isn't cold. Atoms in space are cold though.

Things cool down when lower energy atoms collide (or 'steal') energy from hotter (higher energy) atoms.

Because space is so close to empty, there are very, very few atoms to collide into.

Thus, things don't cool off very easily in space. It's weird to think about.

The only good way to cool off in space is by radiation (radiating heat, not nuclear radiation).

You can see the ISS has several radiation flaps specifically meant to remove excess heat from the station.

This is because of what I said in the paragraph above; heat doesn't convect, or conduct away from the space station very easily.

The only reasonable method is by radiation, which is usually a pretty poor method of spreading heat (what's hotter: touching a pan held over a flame for 2 hours, or hold your hand .5 inches above the pan?)

Fascinating, no?

[tlowe90]

this is all very interesting guys! i learned a lot that i didn't even think about before. so thank you for the edu-macation XD