Vavilov, Sergey Ivanovich
VAVILOV, SERGEY IVANOVICH
(b. Moscow, Russia, 24 March 1891; d. Moscow, 25 January 1951). Physics.
Vavilov, the son of a manufacturer and trader, and the youngest brother of the botanist Nikolay Ivanovich Vavilov, received his secondary education at the Moscow Commercial School, concentrating on physics and chemistry. In 1909 he entered the Faculty of Physics and Mathematics of Moscow University, and by the end of the first year he had chosen a subject on which to work in Lebedev’s laboratory, under the supervision of P. P. Lazarev. Vavilov did not finish this work, however, for in 1911 Lebedev and Lazarev left Moscow University to protest the violation of the university’s autonomy by the minister of education, L. A. Kasso. Vavilov’s scientific work was transferred to Shanyansky City University, a small private institution in Moscow, where Lebedev’s laboratory was set up.
In 1913 Vavilov published his first scientific work, on the photometry of polychromatic light sources; at the same time he carried out research on a subject proposed by Lazarev, who was then studying the discoloration by light of collodion films colored with cyanine dyes. Assigned to investigate the discoloration of these dyes through heating, Vavilov constructed an ingenious experimental device and discovered the essentail differences between the discolorations caused by light and by heat. The work was published in 1914, and Vavilov received a gold medal for it (1915). At the beginning of World War I, he was drafted into the army and sent to the front. Throughout the conflict he served mainly in the technical units; and in his mobile radio laboratory he was able to conduct research in radiotechnology, the results of which were published in 1919.
Discharged from the army in 1918, Vavilov began independent scientific work on photoluminescence and physical optics in general at the Institute of Physics and Biophysics, which was directed by Lazarev. At the same time he was a Privatdozent at the Moscow Higher Technical School, where in 1920 he became professor and head of the department of general physics at Moscow University, and from 1930 all of his work was carried out there. He was elected corresponding member of the Academy of Sciences of the U.S.S.R. in 1931, and the following year was named scientific director of the State Optical Institute now named for him. At this time Vavilov moved to Leningrad but retained his affiliation with Moscow University. At the State Optical Institute he conducted wide-ranging and fruitful work in a new laboratory for luminescence.
In 1932 Vavilov was elected full member of the Academy of Sciences of the U.S.S.R. and became director of the Physics Institute of the Academy of Sciences in Leningrad. Two years later, when the Academy of Sciences of the U.S.S.R. was transferred to Moscow, this institute came with it and through Vavilov’s efforts, became the important P. N. Lebedev Physical Institute.
During World War II, Vavilov worked on problems connected with national defense, although the State Optical Institute was evacuated to Yoshkar-Ola and the Physics Institute to Kazan. These institutes provided much of the high-quality optical equipment needed by the Soviet armed forces. In 1943 Vavilov was named commissioner of the State Committee for Defense of the U.S.S.R. and was awarded the Order of Lenin and the State Prize. He was elected president of the Academy of Sciences of the U.S.S.R. while retaining all of his other positions, and in 1945 was awarded a second Order of Lenin. As president of the Academy of Sciences, Vavilov was particularly concerned with the relation of science to the national economy and aided the development of scientific institutions in the national republics and in the major industrial regions.
Vavilov conducted important research aimed at determining what proportion of absorbed light is converted into fluorescent light. Although it had been assumed that this portion is extremely small. Vavilov showed that the energy output of fluorescence reaches 70–80 percent and in some cases approaches 100 percent. In his research on the polarization of fluorescence, he was the first to show that the degree of polarization depends on the wavelength of the light that stimulates the fluorescence. This finding led to the creation of the study of the spectra of fluorescence. Under Vavilov’s leadership a detailed method of luminescent analysis was elaborated and luminescent lamps were developed. His research was described in Mikrostruktura sveta (“Microstructure of Light”), an original proof of the quantum nature of light.
A major discovery made under Vavilov’s supervision was the Vavilov–Cherenkov effect, a special kind of luminescence that occurs when charged molecules in a medium move at a velocity exceeding the velocity of light in that medium. For this work P. A. Cherenkov, I. Y. Tamm, and I. M. Frank were awarded the Nobel Prize in 1958, seven years after Vavilov’s death.
Vavilov’s works in the history of science include a Russian translation and commentary on Newton’s Optiks and his Lectures on Optics, a work on Galileo’s place in the history of optics, and a popular biography of Newton.
I. Original Works. Vavilov’s collected works were published as Sobranie sochineny, 5 vols. (Moscow, 1952–1956), with biographical sketch by V. L. Levshin. See also Mikrostruktura sveta (“The Microstructure of Light”; 2nd ed., rev. and enl., Moscow-Leningrad, 1945); and Glaz i solntse (“The Eye and the Sun”; Moscow–Leningrad, 1950).
II. Secondary Literature. See N. I. Artobolevsky, Vydayushchysya sovetsky ucheny i obshchestvenny deyatel S. I. Vavilov (“The Distinguished Soviet Scientist and Social Activist S. I. Vavilov”; Moscow, 1961), which includes a bibliography of his basic scientific works; and E. V. Shpolsky, Vydayushchysya sovetsky ucheny S. I. Vavilov (Moscow, 1956). A collection of articles commemorating his seventieth birthday was publisihed in Uspekhi fizicheskikh nauk, 75 , no. 2 (1961).