Sergei Rodionov

Born Sept. 23 (Oct. 6), 1907, in Kiev; died Apr. 23, 1968, in Leningrad. Soviet physicist. Doctor of physicomathematical sciences (1942).

Rodionov studied at the Leningrad Polytechnic Institute from 1926 to 1929. He was on the staff of the Leningrad Physi-cotechnical Institute from 1927 to 1932, the Leningrad Institute of Agronomic Physics from 1932 to 1935, and the All-Union Institute of Experimental Medicine from 1935 to 1939. In 1939 he became affiliated with Leningrad State University, where he was appointed a professor in 1942. Rodionov’s most important works dealt with the electrophotometry of small light fluxes and the optics of the atmosphere. He built the first photon counter in 1930 and discovered the anomalous transmittance of the atmosphere at low solar elevation in 1936.