Electromagnetism began in the nineteenth century when Faraday showed
electricity and magnetism were not distinct, separate phenomena, but
interacted when there were time-varying electric or magnetic fields. In
Electricity and Magnetism I have shown from first principles how
Faraday's experiments led finally to Maxwell's four equations, which
with the electromagnetic-force law summarise the whole of classical
electromagnetism. This book therefore begins with Maxwell's equations
and then uses them to study the propagation and generation of
electromagnetic waves. Physics is a subject in which the more advanced
the treatment of a topic, the deeper the understanding of common
occurrences that is revealed. In studying the solutions of Maxwell's
equations you will find answers to such questions as: What is an
electro- magnetic wave? Why does a radio wave travel through space at
the speed of light? How is a radio wave generated? Why does light pass
through a straight tunnel when a radio wave does not? How does light
travel down a curved glass fibre? It is a remarkable fact that the
classical laws of electromagnetism are fully consistent with Einstein's
special theory of relativity and this is discussed in Chapter 2. The
following four chapters provide solutions of Maxwell's equations for the
propagation of electro- magnetic waves in free space, in dielectrics,
across interfaces and in conductors respectively.
