This note from Tom Knight got deflected by the list software. Sorry TK. -- Rich ------------------ Subject: Re: [math-fun] Ultraviolet catastrophe & Maxwell's demon This can't work, as you point out. As with all complex situations, this one will be difficult to fully analyze, but the problem almost certainly lies in the finite temperature of the photonic crystal. The crystal will come into equilibrium with the black body temperature, and then will emit isotropically a photon spectrum identical to the original black body. The reason we have the second law of thermodynamics is that you don't have to fully analyze such a situation to realize it can't work. How embarrassing.