It is a thought experiment:
Imagine two bodies (A and B) of different surface area, made of the same material. Imagine all heat radiation of body A could be directed to body B and all radiation of Body B could be directed to body A.
After some time this would lead to a balance of radiation. Radiation from A to B would equal radiation from B to A.
As the bodies have different surface areas, this would lead to the interesting effekt, that the temperatures of these two bodies would be different.
What happens if you use these two different temperatures to power a heat engine? Is this a way to get entropy from enthalpy?
Hi welcome to the forum,
Good thought experiment but according to the zeroth law of thermodynamics, the temperature of both the surface will be/should be exactly equal at equilibrium. Isn't it?