Introduction

There are a number of ways in which the subject of thermal physics may be approached. Both classical and quantum mechanical descriptions are introduced in discussing the microstates of large systems, with the quantum state description preferred in the development of the subject that is presented in this book. Useful relations that involve temperature, such as equations of state and the equipartition of energy theorem, are given in later sections in this chapter. For ideal gases, kinetic theory provides an important result known as the equipartition of energy theorem, which the people now consider along with other kinetic theory results. The equipartition of energy theorem may be justified with the aid of the ideal gas equation of state. To describe many thermodynamic processes, it is necessary to introduce the concept of thermal energy transfer or heat flow. A surrounding blanket material converts the neutron energy into heat to power an electricity generator.