What is Thermodynamics?

In this course, we shall focus almost exclusively on those physical properties of everyday materials that are associated with the motions of their constituent atoms or molecules. In particular, we shall be concerned with the type of motion that we normally call ``heat.'' We shall try to establish what controls the flow of heat from one body to another when they are brought into thermal contact. We shall also attempt to understand the relationship between heat and mechanical work. For instance, to what extent does the heat content of a body increase when mechanical work is done on it? More importantly, can we extract heat from a given body in order to do useful work on some other body? This subject area is called ``thermodynamics,'' from the Greek roots thermon, meaning ``heat,'' and dunamis, meaning ``power.''