You will learn to apply the general laws of energy and entropy to engines, refrigerators, chemical reactions, phase transformations, and mixtures.

This book will give you a working understanding of thermal physics, assuming that you have already studied introductory physics and calculus. Alternatively, we can measure the bulk properties of a material, and from these infer something about the particles it is made of. So in thermal physics we assume that these motions are random, and we use the laws of probability to predict how the material as a whole ought to behave. We can't possibly follow every detail of the motions of so many particles. Examples include the air in a balloon, the water in a lake, the electrons in a chunk of metal, and the photons given off by the sun. Thermal physics deals with collections of large numbers of particles - typically 10 to the 23rd power or so.