On 09/08/15 18:21, Alastair McDonald wrote:
"RedAcer" wrote in message
...
On 08/08/15 18:11, Alastair McDonald wrote:
"Eskimo Will" wrote in message
...

I really canot understand why this is being discussed at such length.
The
laws of thermodynamics state that heat energy (radiation is a form of
heat) flows from warm to cold and entropy increases, end of, surely?

I now realise that the problem is that we are talking at cross purposes.
They are talking about the balance of radiation which results in a NET
flow
of heat from warm to cold. I am talking about the cooler of those two
flows,
which is called cold radiation.

If there is a body at x^0 centigrade alone in space; is it emitting:-

radiation,
hot radiation,
cold radiation,
something else ?

What would 99.999999999999999% of physicists' or maybe, engineers say?


I think 100% of engineers and 99% of scientists would say it is emitting
blackbody radiation. It is only cold radiation if/when it arrives at a
warmer body which, from a 0C body, is most likely. So it would be hot
radiation when it arrived at a tank of liquid nitrogen or a block of dry
ice.
WRONG! - explained elsewhere.