M. BORN. Probleme der Atomdynamik. Pp. VIII + 183, Verlag J. Springer, Berlin. 1926.

M. Born. Problems of Atomic Dynamics.

Born’s new little book is an exposition of his American lectures, delivered in the winter semester of 1925/26. In January 1926 these lectures appeared in English in Cambridge (Mass., America), and in April 1926, when signing the preface to the German edition, the author already had to point to a number of changes and additions introduced by the development of the subject during those few months, and to mention a number of important works that could no longer be presented. At the present time their number has grown considerably further. In general, even against the background of the extraordinarily rapid pace characteristic of the development of atomic theory, the movement created by the “new quantum mechanics” of Heisenberg and Born seems dizzyingly fast, although thus far it has mainly carried along German physicists.

Of the thirty lectures that make up the contents of the book under review, the first eight present a brief exposition of the questions to which Born’s Vorlesungen über Atommechanik is devoted, while the last ten summarize the theory of solid-state lattices, which is set forth in his well-known monograph. Lectures 9 to 20 are devoted to an exposition of the new quantum mechanics, its physical and mathematical foundations (the concept of matrix calculus), and certain applications. Here we have the first systematic exposition of these questions. However, given the extreme concision by which it is characterized, it must be recognized as almost as difficult as the journal articles themselves. Systematic work is required of the reader, and the book is only a guide—and not a very generous one in the way of explanations.

On the other hand, all the shortcomings and difficulties that have arisen on the path of atomic theory and have compelled the search for new ways to create a new quantum mechanics are presented with extraordinary vividness. It is still extremely far from any established and finished form, and, accordingly, the indicated chapters of Probleme are still very far from the orderly systematic character of the Vorlesungen über Atommechanik.

Unfortunately, the book contains quite a few misprints, which often make reading it very difficult.

Gr. Landsberg.