On 10/08/15 15:12, Alastair McDonald wrote:
"RedAcer" wrote in message

The hotter body will cool anyway whether the colder body is there or
not. The radiation from the colder body means that the hot body will
cool more slowly that it would have done if the cold body weren't there.
It is not 'cold' radiation as you keep insisting. It does not cool the
hot body, it warms it up.(I'm assuming no background bodies or source of
radiation)

There is always background radiation of one type or another. Think about
it. You are either surrounded by walls, or by the earth and sky, or by
cosmic background radiation. Describe a real situation where it does not
exist.

We are all trying to explain some physics to you. The way that it's done
(in any physics class/book) is to concentrate on the salient features of
interest in the system and ignore/minimise other 'smaller' effects.
Assume we doing the experiment out in space where the CMBR is at 2.3K.
Let the cold body be at 200K and the hot at 300K. OK.
Terms of in the SB equation are proportional to T^4 and so can easily be
ignored in a first approximation.


Cheers, Alastair.