Stoletov, Aleksandr Grigorevich
Stoletov, Aleksandr Grigor’evich
Born July 29, (Aug. 10), 1839, in Vladimir; died May 15 (27), 1896, in Moscow. Russian physicist.
Stoletov was the son of a merchant. After graduating from Moscow University in 1860, he remained at the university to prepare for the rank of professor. Between 1862 and 1866 he did advanced study under H. G. Magnus in Berlin, under G. Kirchhoff in Heidelberg, and under W. Weber in Göttingen. He became an instructor at Moscow University in 1866 and a professor at the university in 1873.
Stoletov’s principal works were devoted to problems of electricity and magnetism. In his doctoral dissertation, “An Investigation of the Magnetization Function of Soft Iron” (1872), he showed that the curve for the dependence of the magnetic susceptibility on the strength of the magnetic field has a maximum, a finding of considerable importance for electrical engineering. In 1876 he measured the ratio of electromagnetic and electrostatic units and obtained a value close to the value of the speed of light. This work, which was carried out before the experiments of H. Hertz, and Stoletov’s proposal for conducting measurements of the ratio in an organized manner (the proposal was adopted by the First Congress of Electricians in 1881) contributed to the acceptance of the electromagnetic theory of light.
In 1888, Stoletov began a systematic study of the photoemis-sive effect; this work brought him worldwide recognition. He designed an original set of experiments and discovered the first law of the photoemissive effect: the intensity of the photocurrent is directly proportional to what he called the energy of the active rays—that is, the intensity of the incident light. Stoletov suggested the possibility of using the photoemissive effect in photometry. Independently of other investigators, he invented the photocell. He also discovered the dependence of the photocurrent on the frequency of the incident light and the phenomenon of the fatigue of a photocathode upon prolonged irradiation. In a study of the dependence of the photocurrent on gas pressure, Stoletov made an important contribution to the theory of the semi-self-maintained gas discharge by establishing that the ratio of the intensity of the electric field to the gas pressure at maximum current is a constant (Stoletov constant). Between 1882 and 1894 he investigated methods for determining the critical state.
Stoletov did a great amount of scientific organizational and pedagogical work. He founded a physics laboratory at Moscow University that was provided with the most up-to-date equipment and initiated the founding of the Institute of Physics of Moscow University. Stoletov and his students substantially raised the level of physics teaching and research in Russia. He was chairman of the physics division of the Society of Lovers of Natural Science, Anthropology, and Ethnology from 1881 to 1889. He also served as director of the department of applied physics of the Polytechnical Museum. Stoletov was the author of essays on the history of science. All his work contributed to the popularization of physical knowledge.
Stoletov took part in the First and Second International Congresses of Electricians and was a member of a number of foreign scientific societies. He was not, however, elected to the St. Petersburg Academy of Sciences. His membership was voted on in 1893 but was undeservedly defeated.
WORKSSobr. soch., vols. 1–3. Moscow-Leningrad, 1939–47.
Izbr. soch. Moscow-Leningrad, 1950.
REFERENCESOcherkipo istorii fiziki v Rossii. Moscow, 1949.
Bolkhovitinov, V. N. Stoletov. Moscow, 1965.
Istoriia estestvoznaniia v Rossii, vol. 2. Moscow, 1960.
Doklady i malerialy mezhvuzovskoi nauchnoi konferentsii, posviash chennoi 130-letiiu so dnia rozhdeniia A. G. Stoletova, 28–30 iiunia 1969. Vladimir, 1970.
Tepliakov, G. M., and P. S. Kudriavtsev. Aleksandr Grigor’evich Stoletov. Moscow, 1966.
O. A. LEZHNEVA