ABSTRACT
This chapter looks at somewhat formal aspects of thermodynamics. There is a very clear parallel to be found in almost all important theories of physics. Taking the example of classical mechanics, a practical approach would be to concentrate on solving Isaac Newton’s equations with appropriate initial conditions. In thermodynamics too we would like to ask what the degrees of freedom are. In mechanics, the three laws ascribed to Newton define a framework within which complete description of all mechanical systems is sought to be found. In the mechanical example, while one could have worked just with velocities, the axiomatic introduction of a momentum is indeed a great step forward conceptually. A major difference between mechanics and thermodynamics is the irrelevance of the notion of time in purely equilibrium thermodynamics. The very important notion of extensive and intensive variables enters. The fundamental equations are relations among only the extensive variables, and are homogeneous equations of first degree.
