Fridman, Aleksandr

(A. A. Friedmann). Born June 17 (29), 1888, in St. Petersburg; died Sept. 16, 1925, in Leningrad. Soviet scientist. A founder of contemporary dynamic meteorology.

Fridman graduated from the University of St. Petersburg in 1910. In 1913 he joined the staff of the Pavlovsk Aerological Observatory. From 1914 to 1917, he helped organize the air navigation and aerological service of the Russian Army. He was a professor at the University of Perm’ from 1918 to 1920. In 1920, Fridman joined the staff of the Main Physical Observatory and the faculties of a number of higher educational institutions in Petrograd. In 1925, in order to carry out scientific research, he ascended in a balloon to an altitude of 7.4 km.

Fridman’s main works dealt with hydrodynamics, dynamic meteorology, and theoretical physics. In 1922, Fridman derived a general equation for determining vorticity; the equation became a fundamental tool in the theory of weather forecasting. In 1924 and 1925, Fridman, together with L. V. Keller, proposed a system of structural characteristics for turbulent flows and constructed a closed system of equations that coupled velocity and pressure pulsations at two points in a flow at various moments in time. These works laid the foundation for present-day statistical theories of turbulence. Between 1922 and 1924, Fridman proposed a model of a nonstatic universe (the Friedmann universe), which provided the basis for modern cosmology.

Fridman received the V. I. Lenin Award posthumously in 1931.