Pyotr Leonidovich Kapitsa

Pyotr Leonidovich Kapitsa
(1933)

Soviet physicist who was a corecipient of the Nobel Prize for Physics in 1978 for his research in magnetism and low-temperature physics. He discovered that helium II (the stable form of liquid helium below 2.174 K, or -270.976 C) has almost no viscosity (i.e., resistance to flow). This property is called superfluidity. (The award was shared by astronomers Arno Penzias and Robert Woodrow Wilson for unrelated work.)
Educated at the Petrograd Polytechnical Institute, Kapitsa remained there as a lecturer until 1921. After his first wife and their two small children died of illness during the chaos of the civil war that followed the Revolution, he went to England to study at the University of Cambridge. There he worked with Ernest Rutherford and became assistant director of magnetic research at the Cavendish Laboratory in 1924, designing apparatus that achieved a magnetic field of 500,000 gauss, which was not surpassed in strength until 1956. He was made a fellow of Trinity College, Cambridge, in 1925 and elected to the Royal Society in 1929, one of only a small number of foreigners to become a fellow. The Royal Society Mond Laboratory was built at Cambridge especially for him in 1932.

In 1934, before he had published his paper on an expansion engine that liquefies helium, Kapitsa went to a professional meeting in the Soviet Union, where his passport was seized and he was detained there by Stalin's orders. In 1935 he was made director of the Institute of Physical Problems of the Soviet Academy of Sciences in Moscow and managed through the intercession of Rutherford to have the Mond Laboratory apparatus shipped to Moscow. He continued his research in low-temperature physics and discovered superfluidity in helium II while investigating its heat-conduction properties. His findings were first published in 1938, with further research on the subject described in The Heat Transfer and Superfluidity of Helium II (1941) and Research into the Mechanism of Heat Transfer in Helium II (1941). In 1939 he built apparatus for producing large quantities of liquid oxygen for the Soviet steel industry during World War II. For his achievements in science during the 1930s and 1940s, Kapitsa was given many honours by the Soviet government, including the title Hero of Socialist Labour (1945), the Soviet Union's highest civilian award.

In 1946 Kapitsa apparently refused to work on nuclear weapons development and as a result fell out of favour with Stalin. He was dismissed from his post as head of the Institute for Physical Problems and resided at his country house, or dacha, until after Stalin's death in 1953. He conducted original researches on ball lightning during his seclusion. Kapitsa was then restored (1955) as director of the institute, a position he kept until his death.

Kapitsa's research on high-power microwave generators in the late 1950s turned his interests to controlled thermonuclear fusion, upon which he published a series of papers beginning in 1969. An outspoken advocate of free scientific thought, in the 1960s he was one of the Soviet scientists who campaigned to preserve Lake Baikal from industrial pollution. He was also active in the Pugwash movement, a series of international conferences aimed at channeling scientific research into constructive rather than destructive purposes.