Photo from the Nobel Foundation archive.
Ben Roy Mottelson
Born: 9 July 1926, Chicago, IL, USA
Affiliation at the time of the award: Nordita, Copenhagen, Denmark
Prize motivation: "for the discovery of the connection between collective motion and particle motion in atomic nuclei and the development of the theory of the structure of the atomic nucleus based on this connection."
Prize share: 1/3
According to modern physics, an atomic nucleus consists of nucleons - protons and neutrons. In earlier models the nucleus was depicted as being spherical, but this proved to be inaccurate. In 1950 James Rainwater postulated that the atomic nucleus can be distorted. The nucleons in the outer portions of the atomic nucleus move about in paths and interact with nucleons inside, causing the nucleus to be distorted. Independently of Rainwater, Aage Bohr arrived at the same theory and corroborated it through experiments in collaboration with Ben Mottelson in 1952 and 1953.