thermodynamic theory says every object of sufficient size gives off radiation proportional to its temperature. there is no arbitrary choice of whether to radiate or not.
When the object is a black body in a vacuum at 0 degrees K. You guys always fail to mention that fact. Once you are no longer talking about a black body and it is out of the vacuum and the surroundings are above 0 degrees K...the equation clearly shows that things begin to change,
in the special case where both the object and the surroundings are the same temperature, both continue to fully radiate according to their temperature but the power is zero because they are both gaining energy as fast as they are radiating it away.
Yeah....heard it before. The thing is though, that according to the SB law, P does not represent "net" energy flow.
SSDD purposely confuses the basic principle of 'every object radiates according to its temperature' with the equation for Power/energy transfer that is dependent on a temperature differential. he declares that the power describes the actual radiation, eg the warmer object emits less than the basic principle demands and the cooler object doesnt radiate at all.
The Stefan Boltzmann Law
The Stefan-Boltzman Law for Black Body Radiation
http://www.public.asu.edu/~hhuang38/mae578_lecture_03.pdf
Here is an informative clip from that last one
This is known as Stefan-Boltzmann law, which states that the rate of outward radiative energy (per unit area) emitted by an object with temperature T is proportional to the 4th power of T
Note that the SB law is, in fact, talking about rates of outward radiative energy....not net energy flows or any other addendum you would care to add to the law in an effort to make it support your beliefs. Simply rate of outward energy flow....no more...no less.
SSDD cannot let go of this folly because if he did then his worldview of thermodynamics would fall apart.
It isn't me, Ian, who is adding words like net, and statistical to the actual statements of the law in an effort to support my argument...that is you and yours. I am satisfied with the laws as they are stated and until you and yours actually prove that they are wrong, they will remain as they are and state what they state and you will still be making statements that don't agree with the laws. When QM actually proves that energy movement is a net proposition, the laws of thermodynamics will be changed and rewritten to reflect that proof. As of now, they don't which makes me right and you wrong.