"Chris L Peterson" wrote in message
...
On Sat, 25 Jul 2009 20:13:50 +0100, "Androcles"
wrote:

Previously I stated "All matter emits radiation unless it is at zero
kelvin.
"
Moron Peterson disputes this by simple assertion, but consider:
a warm body loses heat through radiation and gains heat through
radiation...

I realize you have neither the wits nor scientific literacy to
understand what I'm saying, but I'll provide this for those who come to
this forum with a genuine interest in science:

There are at least two kinds of matter in the Universe, usually called
"ordinary" and "dark". What you're describing is correct for ordinary
matter, but not for dark matter, which does not interact with EM (or
interacts so weakly that we can't yet detect that interaction). Thus it
is incorrect to say that _all_ matter emits radiation when it is warmer
than 0K.
_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

This raises a couple of questions for me ....

1. The equations for black body radiation do not involve the physical nature
of the radiating body. Are you claiming that a macroscopic body composed of
DM would not emit radiation as per the black body equations?

2. On the other side ... I have always just accepted bb radiation as a fact
of hot bodies. Now I have to think about this. I assume that the coupling
between heat and EM derived from the existence of charged particles
(electrons and atomic nuclei) in the radiating body which ultimately accept
EM waves, turn them into electric potential (physical separation of positive
and negative charges) which re-appears as thermal energy, and vice versa.
Note that this is all mediated by charged particles being accelerated by the
E component of the EM wave, or in reverse the acceleration of charged
particles causing EM waves. Thinking about it, how does this work for
neutron starts, which have no charged particles? They absorb and emit bb
radiation, right? If so, what is the physical mechanism for the exchange of
energy between an EM wave and uncharged matter?