On 11/2/2014 5:45 AM, Lostgallifreyan wrote:
rickman wrote in :

I believe there are rather cold temperatures in space. A
superconducting antenna could be used there with *no* supporting
"apparatus".


There's still such a thing as radiation resistance, I think, so it wouldn't
stay cold even there. Given the size of a body, there's a limit to how fast
it can get rid of heat at a given temperature.. I don't know the proper
terminology for it though. Anyway, at low tenperature, the rate it can
radiate heat is low, so it will quickly warm up out of low-temp
superconducting state.

Lol, radiation resistance is from the signal energy *leaving* the
antenna. It does not show up as heat!

You need to read up on the temperatures involved. Space is near
absolute zero. The Sun warms things in the solar system, but before
reaching Uranus even that heat drops to the point of N2 liquifying, 77
°K, still more than 70 °K above the temperature of space. So heat can
still leave liquid nitrogen easily and allow it to freeze at 63 °K at
one atmosphere.

--

Rick