1915 graduated Physico-Mathematical Faculty, Petrograd University.
Specialist in nuclear physics and cosmic rays. Made studies of extended showers of cosmic radiation which led to discovery of phenomenon of nuclear electron showers and nuclear cascade process in cosmic rays. After graduation worked at Leningrad Polytechn.
Institute and Leningrad Physico-Mathematical Institute, then at Moscow University. Since 1950 Chairman, Committee International Lenin Prizes. 1955 headed Soviet delegation at International Conference on the Peaceful Uses of Atomic Energy, Geneva, since 1939 corresponding member, USSR Academy of Science.
Deputy, and member, Commission for Foreign Affairs, Soviet of the Union, USSR Supreme Soviet of 1954 and 1958 convocation.
Religion is bad because it gets people to believe something untrue.