[2] After graduating from Lyons Township High School in La Grange, Illinois, he joined the United States Navy and was sent to attend officers training at Purdue University, where he received a bachelor's degree in 1947.

His thesis adviser was Julian Schwinger, the theoretical physicist who later won the Nobel Prize in 1965 for his work on quantum electrodynamics.

[5] In 1950–1951, James Rainwater and Aage Bohr had developed models of the atomic nucleus which began to take into account the behaviour of the individual nucleons.

In 1952–1953, Bohr and Mottelson published a series of papers demonstrating close agreement between theory and experiment, for example showing that the energy levels of certain nuclei could be described by a rotation spectrum.

In the summer of 1957, David Pines visited Copenhagen, and introduced Bohr and Mottelson to the pairing effect developed in theories of superconductivity, which inspired them to introduce a similar pairing effect to explain the differences in the energy levels between even and odd atomic nuclei.

[10] Rainwater, Bohr and Mottelson were jointly awarded the 1975 Nobel Prize in Physics "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".