S. I. VAVILOV. Experimental Foundations of the Theory of Relativity. Series “The Newest Currents of Scientific Thought.” GIZ, Moscow–Leningrad, 1928. 168 pp. Price 1 rub. 65 kop.

The establishment of the law of conservation of energy was—to a considerable degree—the consequence of the fruitlessness of all attempts to construct a perpetuum mobile. In exactly the same way, the theory of relativity arose as the consequence of the fruitlessness of all attempts to discover the absolute motion of the Earth. No right-thinking physicist would now think of doubting the validity of the law of conservation of energy (at least in its macroscopic form). Yet not a few amateur inventors still continue to devote themselves to constructing machines capable of doing work “out of nothing.”

If such a denial of the principle of conservation of energy is explained by ignorance, on the one hand, and by the enticing character of the idea of a perpetuum mobile, on the other, then the denial of the principle of relativity, which is still encountered among physicists of the old school, is explained solely by a failure to understand it. For the idea of absolute motion, leaving-

BIBLIOGRAPHY

... advanced by opponents of the theory of relativity, in contrast to the idea of perpetuum mobile, contains nothing attractive, offers no practical prospects. The rehabilitation of the idea of “absolute motion,” recently undertaken by D. Miller, caused a great stir. However, verification of Miller’s results by other experimenters did not confirm them, and Miller himself became entangled in contradictions. Thus the commotion raised by Miller served only to strengthen the theory of relativity more firmly.

Acquainting broad circles of both physicists and non-physicists interested in the theory of relativity with the new experimental data was all the more desirable because some of its opponents proved to be greater “Millerites” than Miller himself, in defending his results and in denying the results of other experimenters. In S. I. Vavilov’s little book the reader will find an extremely objective and impartial presentation of both the one and the other. He will also find in it a very interesting summary of a number of earlier experimental investigations that sought to establish the absolute motion of the Earth in space and that have remained partly almost unknown, and partly forgotten. Especially interesting are the attempts to detect first-order effects, whose fundamental impossibility was indicated by Michelson. Further, S. I. Vavilov sets forth Michelson’s and Sagnac’s experiments on the influence of rotational motion on the propagation of light. In Russian literature, a description of these exceedingly interesting experiments appears, apparently, for the first time. Particularly remarkable are Michelson’s and Gale’s experiments on determining the velocity of the Earth’s rotation from the course of light rays in a closed quadrangular circuit. The positive result of these experiments agrees just as well with the general theory of relativity as the negative result of analogous experiments to detect translational motion agrees with the special theory. The last chapters of the book are devoted to the verification of one of the most fundamental consequences of the special theory of relativity—the equivalence of energy and mass in atomic-physical and astrophysical phenomena—and then to the verification of three principal conclusions of the general theory of relativity: the deflection of light rays under the action of gravitation, the precession of Mercury’s orbit, and the “red shift” of spectral lines, i.e., the slowing down of all physical processes in a gravitational field. In the last of these chapters are set forth the most recent investigations by Saint-John and Adams on the companion of Sirius, which provided at the same time a test both of Einstein’s theory and of Eddington’s theory of the “super-dense” state of matter.

In general, S. I. Vavilov’s book is distinguished by interesting theoretical comparisons. The most interesting and surprising of these comparisons are the quotations from Newton that serve as epigraphs to individual chapters of the book. A profound connoisseur of Newton’s works, the author has managed to choose these quotations in an extraordinarily apt and effective way, illustrating the fact that Einstein’s doctrine represents co-

Bibliography

...constitutes a further development of Newton’s doctrine, and by no means its negation, as many are inclined to think. The majestic shadow of Newton gives S. I. Vavilov’s book a special beauty and persuasiveness.

Ya. Frenkel.