The thermodynamics of systems not in thermal equilibrium. The nonequilibrium systems easiest to understand are those near thermal equilibrium; these systems are described by the Onsager relations. For systems far from equilibrium, more complicated patterns, such as chaos and self-organization, can arise due to nonlinearity. Which behaviour is observed depends on the value of certain parameters in the system. The transition from one type of behaviour to another as the parameters are altered occurs at bifurcations.
Subjects: Chemistry — Physics.