Pyotr Leonidovich Kapitsa (1894 – 1984) was an outstanding Soviet physicist who worked with Rutherford and won the Nobel Prize for Physics in 1978. An enigmatic figure, he served as a symbol of science in the Soviet Union during the Stalin era and beyond. From his youth, Kapitsa was a physicist, engineer and an overall handyman. Courage was one of his main traits, both as a scientist and as a person. From 1934-1983 Kapitsa wrote over 300 letters to the Kremlin. His intervention saved physicists Vladimir Fcok, Lev Landau and Ivan Oberimov from labor camps. In the last year of his life he stood up in defense of Andrey Sakharov.
Early Life and Work
Kapitsa was born in the city of Kronstadt, Russia and was a son of military engineer Leonid Petrovich Kapitsa, and Olga Stebnitskaya, educator and folklore researcher. Kapitsa’s studies were interrupted by the First World War, in which he served as an ambulance driver for two years on the Polish front. He graduated from the Petrograd Polytechnical Institute in 1918. In June 1923 Kapitsa received a Ph. D. from Cambridge University. He worked for over ten years with Ernest Rutherford in the Cavendish Laboratory in Cambridge. The professional respect that Kapitsa and Rutherford initially displayed toward each other matured into an enduring and warm friendship. In January 1925 he was appointed Deputy Director of the Cavendish Laboratory on Magnetic Research. In March 1929 he was elected a corresponding member of the USSR Academy of Sciences and in May of that same year became a member of the London Royal Society. He was the first director of the Mond Laboratory from 1930 to 1934.
During the 13 years of his successful work in England Pyotr Kapitsa remained a loyal citizen of the USSR and kept doing all he could to help the development of science in his homeland. During his work in England he was requested numerous times by Soviet officials to return to USSR as his place of residence. In autumn of 1934, Kapitsa came to his homeland to see his loved ones and read a series of lectures in Leningrad, Moscow and Kharkov. He was summoned to the Kremlin and told that starting from that moment, he would have to work in the USSR. On Stalin’s orders, his passport was confiscated by a state that considered his services too valuable to be shared with the West. Kapitsa was a patriotic Russian, with a “friendly” attitude toward the revolution. Although depressed at first, he managed to accept his situation and devoted himself to the advancement of Soviet science. As a result, he spent the remainder of his career in Russia, where he was admired and to some extent protected by Josef Stalin despite Kapitsa’s persistent criticism of Soviet policies. In 1935 he was appointed director of the specially established Institute of Physical Problems in Moscow, where he installed his former equipment from the Mond Laboratory after it was purchased by the Soviet government. Ernest Rutherford cooperated with this venture once it became clear that Kapitsa would not be permitted to return to England. He resumed researching the heat-conduction properties of liquid helium, and in 1938 he discovered super fluidity, or the fact 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).
Campaign with Stalin
Kapitsa’s connection with high politicians proved very effective in the time of Great Purges of 1936-1938, when he attempted to help several arrested scientists. In February 1937 he wrote to Stalin to plead for the arrested Vladimir Fock from Leningrad University. Within few days, the theoretical physicist was released from jail. Vladimir Fock (1898 – 1974) was a Soviet physicist, who did foundational work on quantum mechanics and quantum electrodynamics. His primary scientific contribution lies in the development of quantum physics, although he also contributed significantly to the fields of mechanics, theoretical optics, theory of gravitation, and physics of continuous medium. In April 1938, Lev Landau was observed accepting and discussing an anti-Stalinist pamphlet on the street. He was immediately arrested and imprisoned for over a year as a suspected spy for Germany, a highly unlikely accusation as Landau’s family was Jewish. Kapitsa acted immediately with a personal letter to Stalin but received no response. A year later, in April 1939, he wrote to Molotov claiming that he needed the theoretician’s help to understand recent discoveries in helium, work considered to be important by the authorities. Finally, on April 28, 1939, Kapitsa personally went to the Kremlin and threatened to retire from the position of head of the Institute for Physical Problems. The same day, Landau was released. After his release Landau discovered how to explain Kapitsa’s super fluidity using sound waves, or phonons, and a new excitation called a roton, earning him the 1962 Nobel prize in physics. You can read a short biography about Landau here. In 1941 he helped Ivan Obreimov, the first director of the Kharkov Physico-Technical Institute, gain release from a labor camp.
Duel with Beria
Kapitsa became closely involved with the Soviet atomic bomb project. Kapitsa was a member of the Committee for producing a nuclear bomb and the Chairman of that Committee was under secret police Chief Lavrenty Beria. Tensions soon developed between him and Lavrenty Beria, He continued his extensive letter-writing campaign concerning what he perceived as organizational and directional problems, and subjected even Beria to hostile comments. He wrote Stalin two letters criticizing Beria. He wrote about Beria’s ignorance of physics and his arrogance. Amazingly, Stalin backed Kapitsa, telling Beria he had to get on with the scientists. Kapitsa refused to meet Beria: “If you want to speak to me, then come to the Institute.” Kapitsa refused to work with Beria even when Beria gave him a hunting rifle. Stalin offered to meet Kapitsa, but this never happened.
During World War II, Kapitsa headed the government department in charge of oxygen production. However, in 1946, he refused to work on the development of nuclear weapons. He lost favor with Joseph Stalin. He was placed under house arrest in Zvenigorod, a suburb of Moscow, from 1946 until the death of Stalin in 1953, for refusing to cooperate with Soviet authorities on projects to improve atomic military capability. He was also removed as director of his Institute. By mid-1946 Kapitsa had been dismissed from all of his official appointments, except membership in the Academy of Sciences. After Stalin died in 1953, Beria was ousted by Nikita Khrushchev, who gradually restored Kapitsa’s academic (but not government) positions. In 1955 Kapitsa regained the directorship of the Institute of Physical Problems and kept it until his death (in 1990 the Institute was named after him).
Work and Legacy
In Russia, Kapitsa began a series of experiments to study liquid helium, leading to the discovery in 1937 of its super fluidity. He was later awarded the Nobel Prize in Physics “for basic inventions and discoveries in the area of low-temperature physics”. Immediately after the war, a group of prominent Soviet scientists (including Kapitsa in particular) lobbied the government to create a new technical university, the Moscow Institute of Physics and Technology. Kapitsa taught there for many years. From 1957, he was also a member of the presidium of the Soviet Academy of Sciences and at his death in 1984 was the only presidium member who was not also a member of the Communist Party. Kapitsa was not idle during his years of confinement. He worked on high-power electronics, inventing high-power microwave generators. He continued to study high power electronics and plasma physics. Kapitsa became a well-known public figure, highly respected for his personal courage. He was a member of the Soviet National Committee of the Pugwash Conference of scientists devoted to peace and disarmament. During the worst years of repression, he defended his colleagues, saving some of them from death in the camps. The writer C. P. Snow, who knew him in his Cambridge days, wrote that only when Kapitsa had returned to the Soviet Union did he and his other English colleagues realize
how strong a character he was; how brave he was; and fundamentally what a good man…. If he hadn’t existed, the world would have been worse: that is an epitaph that most of us would like, but don’t deserve.