Symmetry and the order of events in time: the thermodynamics of blackbodiescomposed of positive or negative mass

Abstract

I have previously proposed a discrete symmetry called CPM (charge-parity-mass) symmetry that de nesmatter as having positive mass and antimatter as having negative mass|both being involved in processes that proceedforward in time. I have generalized the second law of thermodynamics to describe and predict the order of events intime that take place in reversible thermodynamic systems composed of positive or negative mass. Here I extend theCPM symmetry to irreversible thermo-optical radiation systems characterized by the Stefan{Boltzmann law, Planck'sblackbody radiation law, and Einstein's law of speci c heat. The laws of radiation analyzed in terms of CPM symmetrymay provide a fresh way of understanding old topics such as the photon and entropy and new topics such as thenonluminous substances in the universe known as dark matter.