[gcr]

Not really. (Disclaimer: I'm not an expert at all, much of what I say is wrong)

Consider your CPU's heat sink. The CPU gets hot, but it can transfer that heat to your metallic heat sink (thermal conduction?), which in turn can dissipate that heat to its surrounding air (thermal convection?).

If you're in space, the only way to get rid of that heat is by radiating it as light (radiation; the same way a metal glows white hot) but that's much less efficient. You can't transfer it to another mass because there isn't other mass in a vaccuum.

[sigstoat]

i think there is a bit of a terminology issue.

to give brudgers as much credit as possible, space is a pretty good heat sink, in that it can absorb all of the heat you can ever produce, without changing temperature. (and since heat transfer is proportional to temperature difference, your transfer rate will never drop because of it.)

but it is terrible for heat transfer.

the metal widgets we stick onto our CPUs aren't really heat sinks, they're for reducing the thermal resistance between the CPU body and the atmosphere, which is the "final" destination for the heat.

[alan-crowe]

Florence explains this to Helix here http://freefall.purrsia.com/ff900/fv00863.htm

[maxerickson]

If you have enough space (err, room) for your radiator, space is a perfect heat sink.