Thermal Radiation Effect in the Free Expansion of an Ideal Gas and Gibbs' Paradox in Classical Thermodynamics

TL;DR

This paper investigates how including thermal radiation interactions in the analysis of ideal gases affects their behavior, leading to more realistic models and resolving Gibbs' paradox in classical thermodynamics.

Contribution

It introduces the consideration of thermal radiation effects into ideal gas models, addressing a gap in standard theory and providing a resolution to Gibbs' paradox.

Findings

Thermal radiation significantly influences ideal gas behavior.

Inclusion of radiation interactions removes Gibbs' paradox.

Gases exhibit more realistic volume change behavior when radiation is considered.

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 since every material absorbs and radiates thermal energy. This interaction may be important in gases since the latter, unlike solids and liquids are capable of undergoing conspicuous volume changes. Taking it into account makes the behaviour of the ideal gases more realistic and removes Gibbs' paradox.