Thermodynamics is the theory that describes the interconversion of work into heat and vice versa. Thermodynamics is the most widely applicable subdiscipline in physics. It applies to astrophysics and to subcellular biology. However, it is not widely known that the foundations of statistical thermodynamics have, until very recently, been based on a series of postulates. The apparent increase in entropy appears to be indirect contradiction with the time reversible equations of motion in mechanics and electrodynamics. Our discovery of the Fluctuation theorem in 1993 and its subsequent confirmation in experiments in 2002, began to change this situation. We now know it is dissipation, not entropy, that is the key to understanding the foundations of statistical thermodynamics.
Prof Denis J. Evans received his PhD in Physics from the Australian National University. He was a postdoc at Oxford and Cornell Universities as well as the US National Bureau of Standards (now National Institute for Standards and Technology). He is a Fellow of the Australian Academy of Science, which awarded him the Craig Medal for chemical research in 2015. He has been a professor of chemistry at the Australian National University since 1989. He is presently a Visiting Professor in the Department of Applied Mathematics.