Symmetry in Processes, Conservation, and Cosmic Considerations

Abstract

In this chapter we discuss and formalize the symmetry of evolution and the symmetry of initial and final states in the analysis of the natural evolution of quasi-isolated systems into initial state and evolution. Symmetry of evolution is also known as symmetry of the laws of nature, and the discussion includes time-reversal symmetry. The considerations of symmetry of initial and final states lead to the equivalence principle and the symmetry principle for natural processes in quasi-isolated systems and to the general and special symmetry evolution principles for such systems. The latter two principles are both concerned with the nondecrease of the degree of symmetry during the evolution of quasi-isolated systems. We obtain an explanation for the empirical observation that macrostates of stable equilibrium of physical systems are often especially symmetric. Symmetry and entropy are shown to be related to each other. Then we discuss conservation and its relation to symmetry of the laws of nature. And finally we indulge in cosmic considerations about it all.