Bibliography

Physics of Dielectrics, edited by A. V. Val’ter, pp. 560, Kh.–L., UPTI, 1932.

The title of this book is somewhat broader than its content. It is not so much the physics of dielectrics as only their electrical properties. In essence, this book is a somewhat peculiar combination of two already published books: Physics of Crystals by Joffe and Theory of Breakdown by Val’ter and others. Questions of breakdown occupy the central place in the book.

The first introductory part is devoted to questions of electrostatics: calculation of electrostatic fields, the classical method of conformal transformations, etc. This purely geometrical chapter, with formulas set off in italics, is written with a thoroughness worthy of a textbook.

The next, small chapter is devoted to questions of polarization in dielectrics. A number of unsuccessful expressions often make it difficult to understand this generally elementary chapter. For example, it is not clear what is meant by the fact that inside the polarized hydrogen atom “the electron and the nucleus have shifted relative to one another,” or, for instance, the incidentally encountered definition of dynamic equilibrium as a state in which the mean position of the electron (in the hydrogen atom) coincides with the position of the nucleus.

The chapter devoted to electrical conductivity is a concise, very systematic, and clearly written summary. True, here, too, attention is disproportionately distributed between gases, liquids, and solid dielectrics. It is concentrated on the latter, which reveals the direction of the author’s interests. The gases obviously suffer from this. Belonging to A. F. Joffe’s school, the author presents the point of view adopted at UPTI (about which, incidentally, the reader is warned in the preface), leaving in the shade evidently erroneous views that have migrated into his textbook (originating, for example, with the recently deceased K. W. Wagner and Guchberg).

The second half of the book is devoted to breakdown. This part is somewhat expanded in comparison with the corresponding chapters of the book by Val’ter and others (Theory and Practice of Breakdown), which we have already mentioned above. Here, again, the chief attention is devoted to solid dielectrics. It is a great pity that the very little-developed question of electronic breakdown is set aside; the mechanism of the latter reduces to the transfer of an electron from a lower, filled energy zone into an “empty,” higher-lying one. These chapters contain rich experimental material, well-presented elements of theory, and it is in this whole part that the book is most interesting and valuable.

The chapter on breakdown in liquid dielectrics naturally represents less work, since on this question there is not a single more or less exhaustive review article in the Russian literature. A fairly substantial bibliography is given here, but the exposition (especially of theoretical work) is rather loose and has a purely qualitative character. Some special theories, for example the Voelker theory of breakdown in a liquid dielectric, are hardly set forth at all. As regards the principal theoretical work in this field, the inadequately critically developed work of Gemant, a much fuller exposition should be sought in Gemant’s own book (Electrophysics of Insulating Materials).

It is a pity that only a few phrases are devoted to the new, extraordinarily interesting point of view on breakdown recently expressed by P. A. Florenskii, who connects the phenomenon of breakdown with phenomena of polarization and reduces it, in this way, to chemical reactions taking place in a dielectric under the action of an electric field.

Recent years have been characterized by the gradual penetration of the ideas of vol–

new mechanics into almost all fields of physics. In the [[unclear: era/field]] Bloch (the main reviews, in Wigner’s works) [[unclear]] a view of the nature of dielectrics. Thanks to [[unclear]], interest turned in this direction. In the field of dielectrics, only the very first steps have been taken so far, whereas the quantum theory of metals has already been developed fairly thoroughly. Nevertheless, in the field of dielectrics there already exist sufficiently definite and extremely established points of view. It is very unfortunate that these new ideas have found no reflection at all in Walter’s book. Throughout the book there runs a view of a dielectric as a crystal with very strongly bound electrons. As is known, however, a conductor differs from a dielectric not at all in the degree of binding of its electrons. The whole question is whether the neighboring energy zones overlap or do not overlap, and the mobility of the electrons here can in no case serve as a criterion.

In addition, a number of questions that are very important for understanding the processes occurring in dielectrics are passed over in complete silence in the book, although the very title of the book calls for their consideration. Thus, the question of the conductivity of dielectrics under illumination is completely absent, unless one counts the small amount devoted to the chapter on the electron-tube conductivity, in which the mechanism of the photocurrent is explained in one phrase, as “the formation of a certain quantity of new gas.”

The book was written by a group of authors, staff members of the Leningrad Electrical-Engineering Combine, under the editorship and direction of A. V. [[unclear: last name]]. Despite some shortcomings and incompleteness, this book should be useful, especially for the electrical engineer, bringing him closer to the physical nature of the phenomena with which he deals in practice.

The book is brilliantly produced from the technical and editorial point of view. We would almost be ready to congratulate the Leningrad branch of the State Technical-Theoretical Publishing House, were it not for the incomparably high price of the book (20 rubles), which makes it completely inaccessible to an individual purchaser.

F. V.