The Microscopic Entropy

However, if we now want to consider processes and equilibria, as, for example, the relaxation processes in Chap. 5 , we know from thermodynamics that these are not determined by the internal energy U. Rather, the central principle of maximum entropy applies. While in mechanics we can understand the system behavior exclusively from the energy, its derivatives, and the forces on the atoms, in thermodynamics the knowledge of the energy does not allow an understanding of the process. Here, the entropy and the 2nd law are required.