The classical mechanics of autonomous microscopic engines

TL;DR

This paper explores the possibility of autonomous microscopic engines, called Hamiltonian daemons, which perform steady energy transfer without macroscopic reservoirs, challenging traditional thermodynamic constraints.

Contribution

It introduces the concept of Hamiltonian daemons as autonomous microscopic engines capable of steady downconversion within purely mechanical systems.

Findings

Hamiltonian daemons can perform steady energy transfer.

Such systems obey different constraints than classical thermodynamics.

Theoretical demonstration of autonomous microscopic engines.

Abstract

Even microscopic engines have hitherto been defined to require macroscopic elements such as heat reservoirs, but here we observe that what makes engines useful is energy transfer across a large ratio of dynamical time scales ("downconversion"), and that small, closed dynamical systems which could perform steady downconversion ("Hamiltonian daemons") would fulfill the practical requirements of autonomous microscopic engines. We show that such daemons are possible, and obey mechanical constraints comparable to, but different from, the laws of thermodynamics.