Sc-Fi technology: question of heating/cooling

[Lord of the Farce]

Yesterday I was working on my created sci-fi race and their technology, with the impression that the more powerful of their "mech's" weaponry can only be used at it's full potential in the near absolute zero temperatures of space, and quite limited when used within atmosphere because of heating/cooling issues.

Then today, I am told by someone that "it would be harder to cool something in a vacuum where there's no medium to carry the heat". Is that correct?

[Larz]

Vacume makes an excellent insulator. And yes, that is true to the sense, you radiate heat in a medium such as atmosphere, but vacume being a perfect insulator does not soak "heat" like atmosphere or any other medium. And space is not near absolute zero or the universe would be one large Jello. Absolute zero means that an atom no longer vibrates, it gives off no energy what-so-ever. It is a barrier much like light, you just can't force your way to because if an atom has no energy, it does not exist. "Near absolute zero" would mean that all matter in space would solid in propertie (cause none of the atoms would be moving). Hope that explains it.

[Guest]

I think in space you would have to get rid of heat in the form of radiation using some form of radiator

[omegaLancer]

that correct, a surface can be used to radiate waste heat from a ship..

[greenmm]

IIRC from Mr. Wong's site, you can radiate heat in space, but apparantly involves the physics of "black-body" radiating objects. Don't understand it completely myself, but I believe it basically means that it's harder to shed excess heat without an adequate conductive medium.

That's why, IIRC, air-cooled machine guns had to have heavier barrels than the first water-cooled ones, because air doesn't cool down the metal as quickly, so they needed a heavier barrel to keep the temperatures manageable.

[Wicked Pilot]

You can only dump excess heat in space by means of radiation. That method is not nearly as quick as convection or conduction. The best way to cool your equipment would be to install large surface cooling panels. The more surface area your ship has the quicker it will radiate the hear away. You could also use water to absorb the heat. When the water gets to a certain temp you could eject it out into space. Of course when you run out of water, you're screwed.

[Lord of the Farce]

Hmmm... guess I'll have to think of some other ideas on how the big weapon are only effective in space and limited within atmosphere... consideration of damage done or size/weight perhaps?