Bibliography

P. A. M. Dirac, Foundations of Quantum Mechanics. Translated from the English by M. P. Bronstein, edited by D. D. Ivanenko, GTTI, 1932.

In presenting quantum physics one may proceed along various paths. One may start from the analogy, already noted by Hamilton, between optics and classical mechanics, an analogy that reflects the profound similarity between light and ponderable matter. This path leads to wave mechanics. One may proceed by way of refining Bohr’s correspondence principle, according to which quantum laws, in the limit, pass over into the laws of classical physics.

This path leads to matrix mechanics. Both paths begin with familiar concepts, step by step introducing the reader into the world of new concepts and phenomena.

In his exposition of quantum physics Dirac adopts an essentially new point of view and develops the presentation independently of the old methods, setting forth quantum mechanics as an autonomous, closed scientific discipline complete in itself.

The first five chapters are devoted to presenting the foundations of the new mathematical apparatus necessary for mastering quantum mechanics. Separate parts of this apparatus had been created long before the appearance of quantum theory, and the task consists in gathering together the parts of algebra and analysis scattered through various branches and arranging them into a single whole.

In the following chapters particular fundamental problems of mechanics are considered: the motion of a particle in a given field of forces, perturbation theory, and the collision problem. In contrast to the English edition, Dirac introduced for the Russian edition a chapter on approximate methods of calculation. The many-body problem, which has enormous practical application in the theory of atoms and molecules, is presented by a method different from those of other authors.

This method has recently made it possible to shorten and simplify the application of group theory in quantum physics and chemistry.

The book ends with an exposition of two famous works by Dirac on the theory of radiation and the relativistic electron.

Since Dirac is one of the founders of the new mechanics, having independently found a whole series of fundamental laws and methods, the book contains almost no references to the works of other authors, so that the reader receives a unified exposition permeated by a single method.

If one raises the question of the suitability of Dirac’s book as a textbook for the reader who is first beginning to become acquainted with quantum physics, the answer must be negative. For the beginner it is far more important to understand the historical development of the new discipline, the linking of new facts with experimental data, the gradual adaptation of concepts and methods of thought to the new material, than to receive a completed, rigorous exposition of foundations derived from a few postulates.

But for a reader already acquainted with quantum mechanics, reading Dirac’s book will be of enormous benefit, by providing a unified foundation for both

clearly showing at what values of the velocities this correction becomes significant.

The appearance of this book, which throws a bridge between physicists of the gas-discharge school and electrical engineers, should be welcomed, and one would like to wish for a translation of this book into Russian. It will undoubtedly be useful not only to engineers, but will also serve as a sufficiently serious introduction for the physicist to the field of electrical phenomena in gases.

G. A. Spivak