Overlooked Work and Heat of Intervention and the Fate of Information Principles of Szilard and Landauer

Abstract

We show that any external intervention (insertion or removal of a partition) that destroys the equilibrium or brings it in a system always requires work and heat to ensure that the first law is obeyed, a fact that has been completely overlooked in the literature. As a consequence, there is no second law violation. We discuss the ramifications of our finding for information principles of Szilard and Landauer and show that no information entropy is needed. The relevance of this result for Maxwell's demon is also considered.