Innovative and wide-ranging, this treatment combines precise mathematic style with strong physical intuition. Written by a well-known physicist for advanced undergraduates and graduate students, the book's broad spectrum of applications includes negative temperatures and heat capacities, general and special relativistic effects, black hole thermodynamics, gravitational collapse, energy conversion problems, and efficiencies including simple heat pump theory. The basic ideas and mathematical formulation of thermodynamics are presented in a modern, clear way with the Carathéodory method, which is employed fully, but in simple terms and without advanced mathematics. Statistical mechanics are based on ideas from information theory, and the simpler ideal systems are covered in close connection with the thermodynamic treatment. Mathematical steps are displayed in detail, and abundant problems include worked solutions.