A. Haas. Matter Waves and Quantum Mechanics. Translated from the 2nd German edition by P. S. Tartakovsky, with a foreword by B. M. Hessen. GIZ, 1930. 192 pp. Price bound: 2 rubles.

Some time ago, in the pages of this journal, we had occasion to review the first German edition of Haas’s book and to recommend it for translation. Now the third German edition has already appeared; moreover, the book has been translated into French and English, and the Russian edition is very timely.

The book treats the most important trend in contemporary theoretical physics and will be read with profit by physicists, mathematicians, astronomers, chemists, and anyone interested in exact natural science. To understand the book, only knowledge of the elements of analysis is needed; it is written extremely simply and clearly. The drawback of the book is its enormous content in a small compass, i.e., excessive concision. Each of the book’s 19 chapters covers a topic that could easily be treated in a separate volume. Suffice it to say that the final chapter, devoted to “Quantum Mechanics and the Philosophy of Nature,” occupies 2 small pages. With such concentration, even despite all the clarity and simplicity of the exposition, an unprepared reader will get an impression of extreme motleyness. In essence, the subject of the book is complex and difficult, and simplicity of exposition has of course been achieved only at the cost of diminished precision and rigor. It seems to us that this shortcoming is not too great a misfortune. The reader should remember that Haas’s book is only an introduction to the new quantum mechanics, or rather a simple summary for a very large and difficult course. It is a great pity that the experimental foundations of wave mechanics are touched upon by Haas extremely superficially. After all, the striking experimental data on the properties of matter waves are the chief support of the theory and, for the beginning reader, the strongest confirmation of the whole doctrine.

The philosophical difficulties of the theory in connection with the revision of the concept of causality in quantum mechanics are touched upon by the author only superficially. They are discussed in detail in the introductory article by B. M. Hessen appended to the Russian translation.

S. Vavilov.