Sergei Eduardovich Frisch (19.06.1899-19.02.1977) was a Soviet physicist and a corresponding member of the USSR Academy of Sciences (1946). He was born in St Petersburg. He graduated from Petrograd University (1921). In 1919 — 39 he worked at the State Optical Institute, and from 1924 at Leningrad University (from 1934 as professor, in 1937 — 47 as dean of the Faculty of Physics, in 1947 — 57 as director of the Institute of Physics at the university).
His work concerned spectroscopy and optics. He studied the interaction of the nucleus with the electron shell, which leads to the appearance of the hyperfine structure of spectra, investigated the hyperfine structure of the sodium lines and established the rule linking the value of the spin of nuclei with their parity, and the hyperfine structure and isotope shifts on the lines of potassium, silver, copper, barium, calcium and other elements. He was one of the first to point to the possibility of investigating gas-discharge plasma by spectroscopic methods. He proposed a method of spectral analysis of gases, widely used in industry. He studied the mechanism of the excitation of high levels of atoms, determined the role of collisions of the second kind, determined the cross-sections of these processes, established the existence of a fine structure of the optical excitation functions, and determined the role of cascade transitions.
He worked on the creation of spectral apparatus and the improvement of light sources. He was the author (together with A. V. Timoreva) of the widely known three-volume “Course of General Physics”. From 1956 he was editor-in-chief of the journal “Optics and Spectroscopy”.