Dissipative structures, dynamics and entropy

A short survey of the phenomenological formulation of the second law and of dissipative structures is presented. The microscopic meaning of entropy and entropy production is then discussed in terms of our formulation of “dynamics of correlations.” It is shown that our formalism applies both to finite quantum mechanical systems and to large systems. The equations of motion of large systems are written in a form which displays explicitly the distinction between reversible processes (which leave the entropy constant) and irreversible processes (which increase the entropy). In this way a unified formulation of dynamics and thermodynamics is achieved.