On 11/2/2014 5:49 PM, Lostgallifreyan wrote:
rickman wrote in :

No, the topic was antenna radiating all the power fed to them.

Specifically, doing it efficiently. Just being hard to match.

Never mind the other bits, beginning to look like old ground already today.
What I might be missing about my comment on some body at some temperature
being limited in its rate of dissipation might be flawed anyway. Never mind
the risk of confusion between an antenna's radiation resistance and what I'm
trying to get at, there's another angle to this...

Am I wrong? Could it be that just as an antenna is efficient regardless of
size, IF you can feed it all the energy you're trying to transmit, is it also
true that regardless of size, that hot body will also equally transmit all
its heat? In other words, is the 'limit' analogous to matching, as in getting
the heat from the bulk volume out to its surface?

I'm hoping that answer(s) to this one might help solve a heap of confusion
for me..

Hmmm... All things emit energy according to their temperature and their
surface emissivity. All things also absorb energy according to their
surface emissivity. Both processes are going on at all times. So an
object loses or gains heat depending on its temperature and the
temperature of the environment. That delta temperature sets the rate
along with the surface emissivity.

In space with the environment near absolute zero (ignoring radiation
from the sun and other nearby objects) any object's radiation of heat
will be near it's maximum potential and limited only by its absolute
temperature. So yes, an object will lose heat according to it's
temperature and that will be less at lower temperatures. But that
doesn't mean a super conductor will warm up unless there is something
heating it.

--

Rick