Critique of some thermodynamic proofs based on the pump-engine couple

TL;DR

This paper critically examines thermodynamic proofs based on the pump-engine couple, highlighting their circular reasoning and emphasizing the need for entropic formulation of the second law for rigorous proofs.

Contribution

It identifies circularity in common thermodynamic proofs and discusses ways to avoid or address these issues, advancing the understanding of thermodynamic foundations.

Findings

Common proofs are circular and of doubtful validity

Some proofs can be avoided with alternative approaches

Entropic formulation is essential for rigorous Carnot theorem proofs

Abstract

We argue that all the common thermodynamic proofs based on the pump-engine couple possess an inherent circularity and hence are of doubtful value. In certain cases, ways of avoiding them are suggested. In others, the difficulties are discussed. Particularly, we emphasize that a neat proof of Carnot theorems requires the entropic formulation of the second law.