About the physicists who had been visiting USSR and who had stayed in the USSR in the 30s.

The 30s of the 20th century were characterized by the rapid development of economics and science in the USSR, and this against the background of the deepest economic crisis in the West, which began with the market crash of 1929. In the first half of the 1930s, in the USSR, astrophysics, quantum physics, nuclear physics and semiconductor theory intensively developed. The centers of this development were Leningrad, Kharkov, Dnepropetrovsk, Kiev, Sverdlovsk. Foreign physicists, including P. Dirac, R. G. Fowler, F. Lange, and others, as well as the returning Russian scientists - L. V. Shubnikov, V. P. Fomin, and others, - sought to get into these centers both for communication and conducting their own research. Repression of 1937-38 suspended this process, but could not completely stop the development of science.