  We present an explicit correspondence between quantum mechanics and the
classical theory of irreversible thermodynamics as developed by Onsager,
Prigogine et al. Our correspondence maps irreversible Gaussian Markov processes
into the semiclassical approximation of quantum mechanics. Quantum-mechanical
propagators are mapped into thermodynamical probability distributions. The
Feynman path integral also arises naturally in this setup. The fact that
quantum mechanics can be translated into thermodynamical language provides
additional support for the conjecture that quantum mechanics is not a
fundamental theory but rather an emergent phenomenon, i.e., an effective
description of some underlying degrees of freedom.
