The Soviet theoretical physicist Lev Davidovich Landau (1908-1968) developed a mathematical theory that explained the properties of superfluidity and superconductivity of helium at temperatures close to absolute zero.

Lev Landau, called "Dau" by his students and close associates, was born on Jan. 22, 1908, in Baku, the capital of Azerbaijan, to parents of middle-class Jewish background. At 14 he entered the University of Baku; then, in 1924, he transferred to Leningrad State University. In 1927 he graduated with a doctorate from the faculty of physics. Between 1927 and 1929 he continued his postgraduate studies at the Physicotechnical Institute of Leningrad.

In 1929 Landau left the Soviet Union to study for a year and a half at the Institute for Theoretical Physics in Copenhagen as well as at scientific centers in Germany, Switzerland, Great Britain, and the Netherlands. During his stay at the institute in Copenhagen, he became closely associated with the Danish physicist Niels Bohr. Bohr...