Ben Roy Mottelson (9 July 1926 – 13 May 2022) was an American-Danish nuclear physicist. He won the 1975

Nobel Prize in Physics ) , image = Nobel Prize.png , alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then " ...

for his work on the non-spherical geometry of atomic nuclei.

Early life

Mottelson was born in Chicago, Illinois on 9 July 1926, the son of Georgia (Blum) and Goodman Mottelson, an engineer. After graduating from

Lyons Township High School Lyons Township High School (often referred to as LTHS or simply LT) is a public high school located in Western Springs, Illinois (South Campus), and also in La Grange, Illinois (North Campus). Lyons Township is a co-educational high school and ...

in La Grange, Illinois, he joined the United States Navy and was sent to attend officers training at

Purdue University Purdue University is a public land-grant research university in West Lafayette, Indiana, and the flagship campus of the Purdue University system. The university was founded in 1869 after Lafayette businessman John Purdue donated land and mone ...

, where he received a

Bachelor's degree A bachelor's degree (from Middle Latin ''baccalaureus'') or baccalaureate (from Modern Latin ''baccalaureatus'') is an undergraduate academic degree awarded by colleges and universities upon completion of a course of study lasting three to six ...

in 1947. He then earned a PhD in nuclear physics from

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of high ...

in 1950. His thesis adviser was

Julian Schwinger Julian Seymour Schwinger (; February 12, 1918 – July 16, 1994) was a Nobel Prize winning American theoretical physicist. He is best known for his work on quantum electrodynamics (QED), in particular for developing a relativistically invariant ...

, the theoretical physicist who later won the Nobel Prize in 1965 for his work on

quantum electrodynamics In particle physics, quantum electrodynamics (QED) is the relativistic quantum field theory of electrodynamics. In essence, it describes how light and matter interact and is the first theory where full agreement between quantum mechanics and spec ...

Career

He moved to Institute for Theoretical Physics (later the

Niels Bohr Institute The Niels Bohr Institute (Danish: ''Niels Bohr Institutet'') is a research institute of the University of Copenhagen. The research of the institute spans astronomy, geophysics, nanotechnology, particle physics, quantum mechanics and biophysics ...

) at the

University of Copenhagen The University of Copenhagen ( da, Københavns Universitet, KU) is a prestigious public research university in Copenhagen, Denmark. Founded in 1479, the University of Copenhagen is the second-oldest university in Scandinavia after Uppsala Unive ...

on the Sheldon Traveling Fellowship from Harvard, and remained in Denmark. In 1953 he was appointed staff member in CERN's Theoretical Study Group, which was based in Copenhagen, a position he held until he became professor at the newly formed Nordic Institute for Theoretical Physics (Nordita) in 1957. He was a visiting professor at the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant u ...

in Spring 1959. In 1971 he became a naturalized Danish citizen. In 1950–1951,

James Rainwater Leo James Rainwater (December 9, 1917 – May 31, 1986) was an American physicist who shared the Nobel Prize in Physics in 1975 for his part in determining the asymmetrical shapes of certain atomic nuclei. During World War II, he worked on the ...

and

Aage Bohr Aage Niels Bohr (; 19 June 1922 – 8 September 2009) was a Danish nuclear physicist who shared the Nobel Prize in Physics in 1975 with Ben Roy Mottelson and James Rainwater "for the discovery of the connection between collective motion and pa ...

had developed models of the

atomic nucleus The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 Geiger–Marsden gold foil experiment. After the discovery of the neutron ...

which began to take into account the behaviour of the individual

nucleon In physics and chemistry, a nucleon is either a proton or a neutron, considered in its role as a component of an atomic nucleus. The number of nucleons in a nucleus defines the atom's mass number (nucleon number). Until the 1960s, nucleons were ...

s. These models, which moved beyond the simpler liquid drop treatment of the nucleus as having effectively no internal structure, were the first models which could explain a number of nuclear properties, including the non-spherical distribution of charge in certain nuclei. Mottelson worked with Aage Bohr to compare the theoretical models with experimental data. 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. This work stimulated new theoretical and experimental studies. 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 In nuclear physics, properties of a nucleus depend on evenness or oddness of its atomic number (proton number) ''Z'', neutron number ''N'' and, consequently, of their sum, the mass number ''A''. Most importantly, oddness of both ''Z'' and ''N'' ...

Nobel Prize (1975)

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".Nobel prize citation
Nobelprize.org. Retrieved on 18 February 2012.

Post–Nobel Prize work

Bohr and Mottelson continued to work together, publishing a two-volume monograph, ''Nuclear Structure''. The first volume, ''Single-Particle Motion,'' appeared in 1969, and the second volume, ''Nuclear Deformations,'' in 1975. Professor Mottelson was a member of the Board of Sponsors of the ''

Bulletin of the Atomic Scientists The ''Bulletin of the Atomic Scientists'' is a nonprofit organization concerning science and global security issues resulting from accelerating technological advances that have negative consequences for humanity. The ''Bulletin'' publishes conte ...

''. He was an honorary member of the

Finnish Society of Sciences and Letters The Finnish Society of Sciences and Letters is a Finnish academy for natural sciences, social sciences and humanities. It is known in Latin as Societas Scientiarum Fennica, in Swedish as Finska Vetenskaps-Societeten, and in Finnish as Suomen Tiede ...

, a member of the

American Philosophical Society The American Philosophical Society (APS), founded in 1743 in Philadelphia, is a scholarly organization that promotes knowledge in the sciences and humanities through research, professional meetings, publications, library resources, and communit ...

, and a foreign fellow of Bangladesh Academy of Sciences and the

Norwegian Academy of Science and Letters The Norwegian Academy of Science and Letters ( no, Det Norske Videnskaps-Akademi, DNVA) is a learned society based in Oslo, Norway. Its purpose is to support the advancement of science and scholarship in Norway. History The Royal Frederick Unive ...

. In 1969, he received the

Atoms for Peace Award The Atoms for Peace Award was established in 1955 through a grant of $1,000,000 by the Ford Motor Company Fund. An independent nonprofit corporation was set up to administer the award for the development or application of peaceful nuclear technol ...

. He acted as director of ECT* (Trento, Italy) from 1993 to 1997.

Personal life

Mottelson was a

dual citizen Dual or Duals may refer to: Paired/two things * Dual (mathematics), a notion of paired concepts that mirror one another ** Dual (category theory), a formalization of mathematical duality *** see more cases in :Duality theories * Dual (grammatical ...

, as he held both

Danish Danish may refer to: * Something of, from, or related to the country of Denmark People * A national or citizen of Denmark, also called a "Dane," see Demographics of Denmark * Culture of Denmark * Danish people or Danes, people with a Danish a ...

and American passports. He lived in

Copenhagen Copenhagen ( or .; da, København ) is the capital and most populous city of Denmark, with a proper population of around 815.000 in the last quarter of 2022; and some 1.370,000 in the urban area; and the wider Copenhagen metropolitan ar ...

. Mottelson was married to Nancy Jane Reno from 1948 until her death in 1975, and they had two sons and one daughter. Mottelson then married Britta Marger Siegumfeldt in 1983. He died on 13 May 2022, in

at the age of 95.

References

External links

Nobel prize press release
* including the Nobel Lecture "Elementary Modes of Excitation in the Nucleus" (11 December 1975) {{DEFAULTSORT:Mottelson, Ben Roy 1926 births 2022 deaths 21st-century American physicists American Nobel laureates American nuclear physicists Atoms for Peace Award recipients Danish Jews Danish Nobel laureates Danish nuclear physicists Danish physicists Fellows of Bangladesh Academy of Sciences Foreign associates of the National Academy of Sciences Harvard University alumni Jewish American scientists Jewish physicists Members of the American Philosophical Society Members of the Norwegian Academy of Science and Letters Nobel laureates in Physics People associated with CERN Purdue University alumni Scientists from Chicago