The amount of black body radiation is proportional to the albedo. Microscopically, this is a result of the fact that the probability of process ‘wall absorbs a photon’ is equal to the probability of the reverse process: ‘wall emits a photon’ Lets assume that it is not true, and probability of absorption is greater than the probability of emission for some material. We make a sphere and make one segment of it from that weird material. We heat the sphere, and when it is filled with Black Body radiation, the wall made of such material overheats, and thermal equilibrium is broken. However, we know (from the decay of neutral kaons) that CP symmetry is broken. Hence, based on CPT theorem, T-symmetry is broken. Hence, there are processes, where the probability of the process and the reverse process are (slightly) different. Hence, there is a loophole in 2nd law?