Ben Roy Mottelson
Mottelson, Ben Roy (1926-), an American-born physicist, shared the 1975 Nobel Prize in physics with Aage Niels Bohr and James Rainwater for devising a theory that combined the earlier liquid-drop and shell models of the atomic nucleus. Their research led to a deeper understanding of the structure of the atomic nucleus.
The second of three children, Benjamin Roy Mottelson grew up and attended primary and high school in the village of La Grange, Illinois. His father had a university degree in engineering. A graduate of Purdue (B.S. degree, 1947) and Harvard (M.A. degree, 1948; Ph.D. degree, 1950), Mottelson moved to Copenhagen for postdoctoral work at the Institute for Theoretical Physics (renamed the Niels Bohr Institute). Later, his research in Copenhagen was funded by the United States Atomic Energy Commission and then by the European Organization for Nuclear Research (CERN), based near Geneva, Switzerland. In 1957, he was appointed professor at the Nordic Institute for Theoretical Atomic Physics (Nordita), whose directorship he assumed in 1981.
Mottelson and Nobel prize-winning Danish physicist, Aage Niels Bohr, one of the sons of Nobel prize-winning physicist Niels Bohr, began a fruitful scientific collaboration in 1951. Together they discovered that the motion of subatomic particles can distort the shape of the atomic nucleus, which was key to bridging the inconsistencies between two earlier nuclear models. One, the liquid-drop model, developed by Niels Bohr in 1936, successfully explained nuclear fission but could not explain other properties of the nucleus. An alternative, the shell model, proposed independently in 1949 by Maria Goeppert Mayer and a group led by J. Hans Jensen, successfully handled some of those deficiencies but inadequately accounted for many properties of the nucleus as a whole. Building upon the theory of James Rainwater, with whom Aage Bohr had worked while at Columbia University in 1949–1950, and paying close attention to new experimental results, Mottelson and Bohr developed a unified theory that provided a clearer picture of nuclear structural dynamics.