Abstract

Thermodynamics occupies a curious position in the body of scientific understanding. It contains arguably the only scientific law that is universally agreed to be inviolable, yet is surrounded by such mystery that it can almost seem an act of faith to believe that it is true. Textbooks pluck random formulae from thin air, with murmurings about Ansätze, and create the general air of ‘well, we can see this works but goodness knows how’. Of course there is always the perfectly correct bottom line – if the model works then it is useful – though even then we jump too quickly to the conclusion that if a model is isomorphic with nature, then nature actually is as proposed by the model, but whilst this ‘we accept it because it works’ bottom line is usually all we have in science anyway, it always begs the question ‘why’, and indeed we feel that until we can get beyond laws of science that merely correctly predict what nature does, and move on to understand the ‘why’, we have hardly started on the task.

Unlike many more fundamental areas of science, thermodynamics occupies a middle ground – it sits on top of quantum and classical mechanics – which for its purposes can be taken, warts and all, as delivered. This means then that one really should be able to answer the question why, and not hide in mystery and Ansätze, and in this seminar I will have a go at showing how this can be done. Much of this is, of course, not new – but I think some genuinely is, and the synthesis of previous work I think also sheds light on the subject.

The seminar assumes a 1B understanding of thermodynamics and that the listener is troubled by the way it is traditionally presented. I hope it will be of interest for those who are supervising undergraduate thermodynamics courses, and that perhaps some who have lectured and written on the subject might come and give a critique of the approach presented.