"Jim Lux" napisal w wiadomosci
...
John - KD5YI wrote:


Again, I'm not sure "temperature" is the relevant measure for something
like that. You can define temperature for a very low pressure gas like
this, but it's not in the same sort of sense as one would apply to a
bulk tangible medium (like air at the Earth's surface or water)

Isaac Asimov touched on this in his book on physics. He said the
temperature up there is high because of the high molecule velocity, but
that *heat* is another matter. So, you can have a high "temperature" even
if the "heat" is practically nil.


I suppose, too, that the whole things still works in terms of, say,
propagation velocity of sound, because that is driven by velocity of
molecules/atoms (and is related to square root of Temperature).

Faraday supposed that this apply to the electric waves. Of course there the
electrons vibrate. The relation to temperature of electrons would be easy to
measure.

So, sound propagates very quickly in the ionosphere (it's got a fairly
high temperature), but because there's not a whole lot of atoms around,
the attenuation will be quite high (essentially infinite, I suspect)

No. Acoustic waves from the Sun (aurora) are et the Earth quite strong.

And that's totally different than propagating something by EM waves.

Electric waves propagate in metal and in space. In the both media the
electrons vibrate. "I suppose we may compare together the matter of the
aether and ordinary matter (as, for instance, the copper of the wire through
which the electricity is conducted), and consider them as alike in their
essential constitution"(Faraday).


That makes you correct. One must carefully state what is meant by
temperature and what is meant by heat.

It would be easy after Schmidt's experiment in vacuum. There the hot cylider
in air bends the light rays and the shadow diameter is bigger than for the
cold cylinder.
The same experiment in vacuum tell us if speed of light is electrons
temperature dependent.
S*