Ben Roy Mottelson

In December 1948, Mottelson married Nancy Jane Reno. The couple had three children - two sons, Malcolm Graham and Daniel John and one daughter, Martha. In 1975, shortly before Mottelson received his Nobel Prize, Nancy Jane Reno died from cancer.

In 1983, Mottelson tied the knot for the second time and married Britta Marger Siegumfeldt.

In his spare time, Mottelson likes to listen to music. He also enjoys bicycle riding and swimming.

Ben Roy Mottelson was born on 9 July, 1926 in Chicago, United States of America. His father, Goodman Mottelson, held a university degree in engineering. His mother’s name was Georgia Mottelson (née Blum). He was the second of his parents’ three children.

Ben spent his early years in La Grange, a suburb located just outside the city of Chicago. During that time, the village had a very healthy atmosphere, where political, moral and scientific issues were openly and vigorously discussed and young Ben was highly influenced by this.

In La Grange, Ben Roy Mottelson attended Lyons Township High School. Upon graduating from there in 1943, he joined the U.S. Navy as part of his war service and was sent to Purdue University to be trained as an officer under the V-12 Navy College Training Program.

Once the war ended, he stayed back at the Purdue University to complete his undergraduate studies, finally receiving his Bachelor of Science degree in 1947. Thereafter, he joined Harvard University for his graduate work and working under Professor Julian Schwinger, he earned his PhD in nuclear physics in 1950.

Soon after receiving his PhD in 1950, Mottelson received one-year Sheldon Traveling Fellowship from the Harvard University. With it, he traveled to Denmark and joined the Institute for Theoretical Physics (later the Niels Bohr Institute) in Copenhagen.

Initially, he planned to spend only the 1950-1951 session at Copenhagen. At that time, the Institute was run by eminent physicist and Nobel laureate Niels Bohr. Under him, the institute grew a tradition of international cooperation and Mottelson enjoyed the atmosphere there.

Fortunately in 1951, he received another fellowship; this time from the U.S. Atomic Energy Commission. It allowed him to stay at Copenhagen for two more years and start collaborating with Aage N. Bohr on the distortions in the shape of a nucleus.

At that time, two principal theories were being circulated. According to Maria Goeppert-Mayer, in a nucleus, independent particles are arranged in shells. This was known as shell theory. The other was liquid drop model, which describes nucleus as a semi-classical fluid made up of neutrons and protons.

However, none of them could explain all aspects of the properties of an atomic nucleus. In 1950, James Rainwater postulated that a nucleus was like a balloon with balls inside.

Mottelson is best known for his experimental work with Aage Bohr, which confirmed that movement of subatomic particles can distort the shape of nuclei. The work not only challenged the accepted notion that all nuclei are perfectly spherical, but also merged Maria Goeppert-Mayer’s shell model with James Rainwater’s liquid drop model.