TABLE OF CONTENTS Electrodynamics as a theory deals with electric charges which move in space and with electromagnetic fields that are produced by the charges and again interact with charges. Electrodynamics is described by Maxwell's equations whose most important consequences are: (a) the electromagnetic nature of light (Maxwell), (b) the emission of electromagnetic waves by an oscillating dipole (H. Hertz), and (c) the unification of electric and magnetic forces. Unlike in Maxwell's days one does not refer to an aether anymore it was Einstein who concluded that this does not exist and instead uses the concept of fields in space. Einstein's Special Theory of Relativity unifies electrodynamics with classical mechanics.
In general a first course in electrodynamics, or electricity and magnetism as it is also called, is preceded by a course in classical mechanics which even today is not always combined with the Special Theory of Relativity (as would be desirable), In addition the concept of a field in space and the distinction between directly observable field quantities and at best indirectly observable field potentials is at that stage still too vague to permit an immediate relativistic field theoretic approach to appear plausible. Moreover, in general the term electrodynamics is usually restricted to macroscopically observable phenomena, so that a quantised treatment with operator-valued fields is beyond its scope, the latter being dealt with in quantum electrodynamics. Thus the classical fields are c-numbers. As a consequence of this restriction, and also in order to...
