Lyndsay G.M. Gordon

11 Guildford Tce., Thorndon, Wellington, New Zealand. E-mail: [email protected]

Received: 29 August 2003 / Accepted: 20 December 2003 / Published: 21 March 2004

Abstract: A mechanism is described which can create a chemical potential gradient from a single heat reservoir. The mechanism is equivalent to a Maxwellian valve. Heat supplies the energy through thermal fluctuations to form the gradient contrary to the second law. A quantitative analysis of the system is given.

Keywords: Maxwell; second law; microscopic irreversibility; Brownian motion; centrifugal force.