MANDELSHTAM, LEONID ISAAKOVICH

MANDELSHTAM, LEONID ISAAKOVICH (1879–1944), Soviet physicist. Mandelshtam was born in Odessa and entered the New Russian (Novorossiyskiy) University in Odessa in 1897. He was expelled one year later for taking part in student protests and completed his education at the University of Strasbourg. He returned to Russia in 1914; in 1918 he was appointed professor at the Odessa Technical Institute. In 1925 he became professor of physics at Moscow University. Mandelshtam's main scientific works were in the fields of optics, theory of oscillations, and radiophysics. In his work Ob opticheski odnorodnykh i mutnykh sredakh ("On optically isotropic and cloudy media," 1907) he disproved J.W. Rayleigh's theory about molecular dispersion of light and showed that the medium must be anisotropic to be able to disperse light. He made several important contributions to the nonlinear theory of oscillations, and together with N.D. Papaleksi invented a new method of creating electrical oscillations. In radiophysics Mandelshtam solved several problems of propagation of radio waves over the surface of the earth. He also proposed the idea of exact distance measurements with the help of radio waves and together with Papaleski built radiointerferometric distance measuring devices. He also wrote papers about statistical and quantum physics and relativity theory, the philosopical basis of which has been criticized lately by the scientific community. From 1931 to 1936 Mandelshtam served as coeditor with abram fyodorovitch joffe of Khimicheskiy Zhurnal, the journal of the Russian Physico-Chemical Society, Leningrad.   Mandelshtam was awarded the Stalin Prize in 1942 for his work on nonlinear oscillations and propagation of radio waves. In 1945 the Academy of Sciences established two prizes in his name for the best work in physics and radio-physics. -BIBLIOGRAPHY: I.V. Kuznetsov (ed.), Lyudi russkoy nauki, 1 (1948), 260–71; A.A. Semyonov, in: Voprosy filosofii, 3 (1953), 199–206; N.D. Papaleski, in: Uspekhi fizicheskikh nauk, 27 no. 2 (1945). (Gerald E. Tauber)