Note on nonequilibrium stationary states and entropy

TL;DR

This paper discusses the ambiguous nature of entropy in nonequilibrium stationary states, proposing that entropy may only be a transfer or creation quantity without a well-defined physical content.

Contribution

It introduces a conjecture that entropy in nonequilibrium stationary states lacks a physical meaning as a property of the system, unlike in equilibrium.

Findings

Entropy in nonequilibrium states may be analogous to heat content in equilibrium.

Entropy might only be a transfer or creation quantity, not a property of the system.

The paper proposes that entropy has no well-defined physical content in nonequilibrium stationary states.

Abstract

In transformations between nonequilibrium stationary states, entropy might be a not well defined concept. It might be analogous to the ``heat content'' in transformations in equilibrium which is not well defined either, if they are not isochoric ({\it i.e.} do involve mechanical work). Hence we conjecture that un a nonequilbrium stationary state the entropy is just a quantity that can be transferred or created, like heat in equilibrium, but has no physical meaning as ``entropy content'' as a property of the system.