Hidden Dissipation and Irreversibility in Maxwell’s Demon

Maxwell’s demon is an entity in a 150-year-old thought experiment that paradoxically appears to violate the second law of thermodynamics by reducing entropy without doing work. It has increasingly practical implications as advances in nanomachinery produce devices that push the thermodynamic limits imposed by the second law. A well-known explanation claiming that information erasure restores second law compliance fails to resolve the paradox because it assumes the second law a priori, and does not predict irreversibility. Instead, a purely mechanical resolution that does not require information theory is presented. The transport fluxes of mass, momentum, and energy involved in the demon’s operation are analyzed and show that they imply “hidden” external work and dissipation. Computing the dissipation leads to a new lower bound on entropy production by the demon. It is strictly positive in all nontrivial cases, providing a more stringent limit than the second law and implying intrinsic thermodynamic irreversibility. The thermodynamic irreversibility is linked with mechanical irreversibility resulting from the spatial asymmetry of the demon’s speed selection criteria, indicating one mechanism by which macroscopic irreversibility may emerge from microscopic dynamics.

A demon of a puzzle

In 1871 James Clerk Maxwell proposed a puzzle now known as “Maxwell’s Demon” in his book Theory of Heat. We celebrate its 150th anniversary in this thermodynamics-themed cryptic crossword compiled by Ian Randall.

Correction to: Conditional Action and Quantum Versions of Maxwell’s Demon

The article “Conditional Action and Quantum Versions of Maxwell’s Demon”, written by Heinz‑Jurgen Schmidt, was originally published electronically on the publisher’s internet portal on 30 September 2020 without open access. With the author(s)’ decision to opt for Open Choice the copyright of the article changed on 17 September 2021 to © The Author(s) 2020 and the article is forthwith distributed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0. The original article has been corrected.

Entropy and Maxwell’s Demon: The Degree of Disorderliness in Concept

The present article is motivated toward delving into the concept of entropy, a fundamental consequence of the second law of thermodynamics with particular emphasis on the thought experiment by James C. Maxwell, famously known as the “Maxwell’s demon”, which in turn enables our visualization of the connection of entropy with information.

Taking the heat

Maxwell's demon and the high cost of erasure.