The book talks about the progress of ideas and discoveries in physics, which have grown like a chain reaction since the beginning of our century and have led to major modern achievements in science and technology. The author tells about the life and scientific work of five outstanding Soviet scientists, whose works played an important role in ideological and thermonuclear research, in the mastery of atomic energy. These are physicists - theorists and experimenters: academicians P. L. Kapitsa, N. II. Semenov, I. E. Tamm, A. I. Alikhanov and corresponding member of the USSR Academy of Sciences Ya. I. Frenkel.