Petr Nikolaevich Lebedev

Born Feb. 24 (Mar. 8), 1866, in Moscow; died there Mar. 1 (14), 1912. Russian physicist. Son of a merchant. From 1887 to 1891 he worked in Strasbourg and Berlin at the laboratories of A. Kundt; F. Kohlrausch; and H. Helmholtz. In 1891 he returned to Russia and began to teach at Moscow University, where he organized a physics laboratory (he became a professor in 1900). In 1911 he resigned in protest against the reactionary policies of L. A. Kasso, the minister of public education, and using private donations he founded a physics laboratory at Shaniavskii University.

While studying the ponderomotive effect of waves on resonators, Lebedev established for the first time the general nature of the laws for waves of various types (acoustic, hydraulic, and electromagnetic). He showed that, for all types of waves, maximum repulsion of resonators occurs under conditions of resonance. In 1895, in his attempts to verify the electromagnetic nature of light, he developed highly precise equipment, which he used to produce the first millimeter electromagnetic waves. He then established their reflection, double refraction, interference, and other phenomena that are inherent in light waves. In 1889 he was the first to observe and measure the pressure of light on a solid body, thus quantitatively confirming Maxwell’s theory. In 1907, Lebedev succeeded in solving the very difficult experimental problem of demonstrating and measuring the pressure of light on a gas. He also studied the role of the earth’s rotation in the origin of terrestrial magnetism. Lebedev founded Russia’s first school of physics, and the Institute of Physics of the Academy of Sciences of the USSR is named for him.