From Rod Swenson, University of Connecticut
Your article about “exergy” misrepresents my work and that of my colleagues (5 October, p 30). Our view, it is said, is that “life works to degrade heat energy – generating the maximum amount of entropy”. James Kay disputes this, saying heat isn’t the only source of energy for life.
Yet our work has never referred to heat energy alone. The standard boilerplate in our papers reads: “The same principle applies to any system where any form of energy is out of equilibrium with its surrounds (such as mechanical, chemical, electrical or energy in the form of heat), a potential exists that the world acts spontaneously to minimise.”
The ideas of Kay and Eric Schneider covered in the feature are not new. Their suggestion that potentials are degraded at the fastest rate given the constraints was suggested and demonstrated more than a decade ago, and it was shown that, as a consequence, the world can be expected to produce as much order as it can.
Storrs, Connecticut, US
