Introduction

This introduction presents an overview of key concepts discussed in the subsequent chapters of this book. The presents the general mathematical account of the theory and of certain definitive aspects of its development. Before the introduction of quantum theory one of the main areas of interest in theoretical physics was the development of the Maxwell-Lorentz equations. In ionospheric physics, radio astronomy and various other aspects of geophysics, astrophysics and "space" physics, as well as laboratory plasma physics and accelerating machines, the classical theory of charged particles is allowed full scope. In the pre-quantum era the field radiated by a charged particle in uniform circular motion was considered in relation to an electron in orbit about a nucleus. The importance of the part played by magnetic fields in influencing the motion of charged particles can hardly be over-emphasized, and it is worth giving some indication of the magnitudes of the fields that may be encountered.