Robert Oppenheimer (22.04.1904-20.02.1967) was an American theoretical physicist, a member of the National Academy of Sciences (1941). He was born in New York. He graduated from Harvard University (1925). He continued his studies at the University of Cambridge under E. Rutherford (1925—26) and at the University of Göttingen under M. Born (1927), where he defended his doctoral dissertation. In 1928 he returned to the USA. In 1929—47 he worked at the University of California and the California Institute of Technology (as professor from 1936). In 1943 — 45 he headed the Los Alamos Scientific Laboratory. In 1947-66 he was director, and in 1947-67 professor, of the Institute for Advanced Study (Princeton). For speaking against the creation of the hydrogen bomb and for the use of atomic energy for peaceful purposes he was removed from all his posts and accused of “disloyalty” (1953).
His research concerned nuclear physics, quantum mechanics, relativity, cosmic-ray physics, elementary particle physics and theoretical astrophysics. Together with M. Born he developed in 1927 a theory of the structure of diatomic molecules. He proposed a method of calculating the distribution of intensities among the components of emission spectra and developed a theory of the interaction of free electrons with atoms. In 1928 he explained the phenomenon of autoionisation of excited states of atomic hydrogen by means of the tunnel effect.
In 1931 he and P. Ehrenfest showed that nuclei consisting of an odd number of particles with spin 1/2 must obey Fermi — Dirac statistics, and those consisting of an even number must obey Bose — Einstein statistics (the Ehrenfest — Oppenheimer theorem). Applying this theorem to the nitrogen nucleus, they showed that the proton-electron hypothesis of the structure of nuclei leads to a number of contradictions with the known properties of nitrogen. Together with M. Phillips he developed (1935) a theory of nuclear stripping reactions (the Oppenheimer — Phillips reactions). He studied the internal conversion of gamma rays and established (1933) the mechanism of pair production. In 1937, together with J. Carlson, he developed the cascade theory of cosmic-ray showers, in 1938 with G. Volkoff he made the first calculation of a model of a neutron star, and in 1939 with J. Snyder he predicted the existence of “black holes”. At Berkeley he collaborated with E. Lawrence on methods of separating the isotopes of uranium. In 1947, independently of others, he explained the “Lamb shift”. His work in the last years was also devoted to general problems of science.
The founder of a scientific school at Berkeley. A member of a number of academies of sciences and scientific societies. In 1948 he was president of the American Physical Society. The E. Fermi Prize (1963).