All shook up: fluctuations, Maxwell's demon and the thermodynamics of computation (Q280654)

Summary: The most successful exorcism of Maxwell's demon is \textit{M. von Smoluchowski}'s observation [Phys. Z. 13, 1069--1080 (1912; JFM 43.1033.04)] that thermal fluctuations would likely disrupt the operation of any molecular-scale demonic machine. A later tradition sought to exorcise Maxwell's demon by assessing the entropic cost of the demon's processing of information. This later tradition fails since these same thermal fluctuations invalidate the molecular-scale manipulations upon which the thermodynamics of computation is based. A new argument concerning conservation of phase space volume shows that all Maxwell's demons must fail.