I was born in Chicago, Illinois, on July 9, 1926, the second of three children of Goodman Mottelson and Georgia Mottelson (née Blum). My father held a university degree in engineering. My childhood home was a place where scientific, political and moral issues were freely and vigorously discussed. I attended primary school and high school in the village of La Grange, Illinois.

Graduating from high school during the second world war, I was sent by the U.S. Navy to Purdue University for officers training (V12 program) and remained there to receive a Bachelor of Science degree in 1947. My graduate studies were at Harvard University and my PhD work on a problem in nuclar physics was directed by Professor Julian Schwinger and completed in 1950.

Receiving a Sheldon Traveling Fellowship from Harvard University I chose to spend the year (1950-51) at the Institute for Theoretical Physics in Copenhagen (later the Niels Bohr Institute) where so much of modern physics had been created and where there were such special traditions for international cooperation. A fellowship from the U.S. Atomic Energy Commission permitted me to continue my work in Copenhagen for two more years after which I held a research position in the CERN (European Organization for Nuclear Research) theoretical study group that was formed in Copenhagen. With the founding of the Nordic Institute for Theoretical Atomic Physics in Copenhagen (1957) I received a position as professor which I have held since. The spring term of 1959 was spent as visiting professor in the University of California at Berkeley.

The close scientific collaboration with Aage Bohr was begun in 1951 and has continued ever since. We feel that in this cooperation we have been able to exploit possibilities that lie in a dialogue between kindred spirits that have been attuned through a long period of common experience and jointly developed understanding. The lectures that are published in this volume attempt a discussion of the main influences that we have built on and the viewpoints that have been developed in this collaboration. It has been our good fortune to work closely together with colleagues at the Niels Bohr Institute and Nordita, including the many outstanding scientists who have come from all parts of the world and have so enriched the scientific atmosphere and personal contacts.

Married Nancy Jane Reno, 1948 (dec. 1975); 3 children, Malcolm Graham (1950), Daniel John (1953), Martha (1954). Married Britta Marger Siegumfeldt, 1983.*

This autobiography/biography was written at the time of the award and later published in the book series Les Prix Nobel/ Nobel Lectures/The Nobel Prizes. The information is sometimes updated with an addendum submitted by the Laureate.

* Updated by the Laureate in February 2005.