Introduction

In our study of classical thermodynamics, we concentrated on the application of statistical physics to macroscopic systems. Somewhat paradoxically, statistical arguments did not figure very prominently in this investigation. In fact, the only statistical statement we made was that it was extremely unlikely that a macroscopic system could violate the second law of thermodynamics. The resolution of this paradox is, of course, that macroscopic systems contain a very large number of particles, and their statistical fluctuations are, therefore, negligible. Let us now apply statistical physics to microscopic systems, such as atoms and molecules. In this study, the underlying statistical nature of thermodynamics will become far more apparent.