Sven Gösta Nilsson (January 14, 1927, Kristianstad – April 24, 1979, Lund) was a Swedish

theoretical physicist Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain and predict natural phenomena. This is in contrast to experimental physics, which uses experimen ...

at the

Lund Institute of Technology The Faculty of Engineering is one of the eight faculties at Lund University in Lund, Sweden, commonly called LTH (after its Swedish name ''Lunds Tekniska Högskola''). LTH has (2022) about 1,500 employees and nearly 10,000 students, of which abo ...

. Nilsson's father was a preacher. As an undergraduate engineering student, he spent a year at Occidental College in California. He obtained a Master of Science in

engineering physics Engineering physics, or engineering science, refers to the study of the combined disciplines of physics, mathematics, chemistry, biology, and engineering, particularly computer, nuclear, electrical, electronic, aerospace, materials or mechanical en ...

at the

Royal Institute of Technology The KTH Royal Institute of Technology ( sv, Kungliga Tekniska högskolan, lit=Royal Institute of Technology), abbreviated KTH, is a public research university in Stockholm, Sweden. KTH conducts research and education in engineering and technolo ...

Stockholm Stockholm () is the Capital city, capital and List of urban areas in Sweden by population, largest city of Sweden as well as the List of urban areas in the Nordic countries, largest urban area in Scandinavia. Approximately 980,000 people liv ...

. Influenced by Tommy Lauritsen and

Torsten Gustafson Torsten Valdemar Gustafson (8 May 1904 – 27 May 1987), was a Swedish physicist and professor in theoretical physics at Lund University. Biography Torsten Gustafson was born on 8 May in Falkenberg, Sweden. After graduating from his high school ...

, Nilsson decided to switch paths from engineering to physics, and in 1950 he was admitted to postgraduate studies in Lund with Gustafson as his supervisor. After early work with Lauritsen on excited states in ⁶Li, Nilsson became interested in evidence that heavy nuclei could be deformed into

ellipsoidal An ellipsoid is a surface that may be obtained from a sphere by deforming it by means of directional scalings, or more generally, of an affine transformation. An ellipsoid is a quadric surface; that is, a surface that may be defined as the z ...

rather than spherical shapes. Rotational bands had been discovered in 1953, an observation that was incompatible with a spherically symmetric shape. Nilsson set out to produce a model for the structure of deformed nuclei, building on work by

Maria Goeppert-Mayer Maria Goeppert Mayer (; June 28, 1906 – February 20, 1972) was a German-born American theoretical physicist, and Nobel laureate in Physics for proposing the nuclear shell model of the atomic nucleus. She was the second woman to win a Nobel Pri ...

that had been published in 1950, as well as work by

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 ...

and

Ben Mottelson Ben Roy Mottelson (9 July 1926 – 13 May 2022) was an American-Danish nuclear physicist. He won the 1975 Nobel Prize in Physics for his work on the non-spherical geometry of atomic nuclei. Early life Mottelson was born in Chicago, Illinois on ...

at the 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 ...

). His research, in collaboration with Bohr and Mottelson, led to the so-called

Nilsson model The Nilsson model is a nuclear shell model treating the atomic nucleus as a deformed sphere. In 1953, the first experimental examples were found of rotational bands in nuclei, with their energy levels following the same J(J+1) pattern of energies as ...

and a 1955 doctoral thesis, "On some properties of nuclear states." Nilsson's main innovations were the introduction of a method for modeling the flat-bottomed shape of the nuclear potential, as well as formulating a model that made calculations practical, and exploiting the digital computing technology of the day. Nilsson and Mottelson embarked on a comprehensive program of comparing nuclear properties with the predictions of the deformed shell model. The Nilsson model was successful in explaining the

spins The spins (as in having "the spins")Diane Marie Leiva. ''The Florida State University College of Education''Women's Voices on College Drinking: The First-Year College Experience"/ref> is an adverse reaction of intoxication that causes a state of v ...

and

magnetic moments In electromagnetism, the magnetic moment is the magnetic strength and orientation of a magnet or other object that produces a magnetic field. Examples of objects that have magnetic moments include loops of electric current (such as electromagne ...

of nuclei far from closed shells, problems which would have been intractable with the spherical shell model. In many cases, a disagreement between theory and experiment led to the discovery that the experimental results had been mistaken. Sven Gösta Nilsson was involved in the work of

CERN The European Organization for Nuclear Research, known as CERN (; ; ), is an intergovernmental organization that operates the largest particle physics laboratory in the world. Established in 1954, it is based in a northwestern suburb of Gene ...

's Theoretical Study Division when the group was located in Copenhagen. More than twenty years later, then in

Geneva Geneva ( ; french: Genève ) frp, Genèva ; german: link=no, Genf ; it, Ginevra ; rm, Genevra is the List of cities in Switzerland, second-most populous city in Switzerland (after Zürich) and the most populous city of Romandy, the French-speaki ...

, he spent a sabbatical period at CERN. Starting in 1963, he was a professor of mathematical physics at the two-year-old Lund University of Technology, helping to build its research programs. In 1974 he was elected to membership in the Royal Swedish Academy of Sciences. He was an active environmentalist and frequent author of newspaper articles. Nilsson is buried at Norra kyrkogården in Lund.

References

{{DEFAULTSORT:Nilsson, Sven Gösta 1927 births 1979 deaths Swedish physicists People from Kristianstad Municipality Academic staff of Lund University KTH Royal Institute of Technology alumni Fellows of the American Physical Society People associated with CERN Members of the Royal Swedish Academy of Sciences