On the Second Law of Classical Thermodynamics
Prof. Dr. Jakob Yngvason (Universität Wien)

The essence of the second law of classical thermodynamics is the 'entropy principle which asserts the existence of an additive and extensive entropy function, S, that is defined for all equilibrium states of thermodynamic systems and whose increase characterizes the possible state changes under adiabatic conditions. It is one of the few truly fundamental physical laws and its consequences are far reaching. In the lecture an account of joint work with Elliott H. Lieb will be given, in which the existence and uniqueness of S is proved to be a consequence of certain basic properties of the relation of adiabatic accessibility among equilibrium states.