Interaction with thermal radiation in the free expansion and mixing of ideal gases and Gibbs' paradox in classical thermodynamics

TL;DR

This paper explores how including thermal radiation interactions in ideal gas models leads to more realistic behavior and resolves Gibbs' paradox, which is not addressed in traditional theory.

Contribution

It introduces a modification to ideal gas theory by accounting for thermal radiation interactions, providing a more physically accurate model and resolving Gibbs' paradox.

Findings

Interaction with thermal radiation affects ideal gas behavior.

Inclusion of radiation interaction removes Gibbs' paradox.

More realistic modeling of gases undergoing volume changes.

Abstract

The standard theory of ideal gases ignores the interaction of the gas particles with the thermal radiation (photon gas) that fills the otherwise vacuum space between them. This is an unphysical feature of the theory since every material in this universe, and hence also the particles of a gas, absorbs and radiates thermal energy. The interaction with the thermal radiation that is contained within the volume of the body may be important in gases since the latter, unlike solids and liquids, are capable of undergoing conspicuous volume changes. Taking this interaction into account makes the behaviour of the ideal gases more realistic and removes Gibbs' paradox.