This book discusses the interaction of light with atoms, concentrating
on the semiclassical descriptions of the processes. It begins by
discussing the classical theory of electromagnetic radiation and its
interaction with a classical charged dipole oscillator. Then, in a
pivotal chapter, the interaction with a free charge is described (the
Compton effect); it is shown that, in order to give agreement with
observation, certain quantum rules must be introduced. The book then
proceeds to discuss the interaction from this point of view-light always
being described classically, atoms described quantum-mechanically, with
quantum rules for the interaction. Subsequent chapters deal with
stimulated emission and absorption, spontaneous emission and decay, the
general problem of light stimulating and being scattered from the
two-state atom, the photoelectric effect, and photoelectric counting
statistics. Finally the author gives a personal view on the nature of
light and his own way of looking at certain paradoxes. The writing of
this book was originally conceived as a collaboration between the
present author and a colleague of former years, Alan V. Durrant. Indeed,
some preliminary exchange of ideas took place in the mid-1970s. But the
problems of joint-authorship from antipodean positions proved too
difficult and the project was abandoned. I would like to record my
indebted- ness to him for the stimulation of this early association. I
also acknowledge the encouragement of my colleagues at the Univer- sity
of Otago. Special reference must be made to D. M.