Physics Nobel Winner Aage Bohr, 87, Dies; Like Father, Studied Atomic Structure

Aage Bohr, left, received the Nobel Prize from Swedish King Carl Gustaf for work on the structure of the nucleus.
Aage Bohr, left, received the Nobel Prize from Swedish King Carl Gustaf for work on the structure of the nucleus. (1975 Polfoto Via Associated Press)
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By Martin Weil
Washington Post Staff Writer
Sunday, September 13, 2009

Aage N. Bohr, 87, the son of Nobel Prize-winning Danish physicist Niels Bohr, who joined his father in fleeing the Nazis during World War II and later won his own Nobel Prize, died Sept. 8 in Copenhagen. The cause of death was not reported.

Niels Bohr was a colossus of science, one of the creators of 20th-century physics and a winner of the 1922 Nobel Prize, whose many achievements included the so-called "liquid drop" model of the nucleus of the atom. Aage Bohr and two colleagues won the Nobel more than 50 years later for a new model of the nucleus, which reconciled the liquid drop model and another model of the nucleus.

In addition to exploring the secrets of the atom and the mysteries of the nucleus, the Bohrs shared lives of adventure, in which they adopted aliases and embarked on secret journeys.

For a time after the Nazis invaded Denmark early in World War II, the Bohr family appeared relatively safe. But Niels Bohr's mother had been Jewish, and in 1943 it became necessary to escape their homeland.

In darkness, a fishing boat took Niels Bohr and his wife Margrethe across the Oresund strait to Sweden, and their children later followed. Niels Bohr was then smuggled into Britain by the Royal Air Force, passing out at high altitude from lack of oxygen.

Aage Bohr later joined his father in England and soon followed him to Los Alamos, N.M., where the atom bomb was being created. Both were given code names: Niels Bohr became Nicholas Baker; his son was known as Jim Baker and worked as his father's assistant. (Italian-born Nobel winner Enrico Fermi was Henry Farmer, and American colleagues were amused at the accents of the bearers of these quintessentially American names.)

At Los Alamos, Aage Bohr sometimes interpreted for his father, who was said to mumble.

Aage Niels Bohr was born in Copenhagen on June 19, 1922. After the war, his family returned to Denmark, and he resumed his interrupted studies, receiving a master's degree in physics from the University of Copenhagen in 1946.

He did advanced study at Princeton and Columbia universities before returning to Copenhagen, where he became a professor of physics and began his research on nuclear structure with Danish physicist Ben Mottelsson.

Niels Bohr's liquid drop model had offered a rudimentary view of how nuclear fission might proceed. A second model, the shell model, was reminiscent of maps of electron positions around the nucleus.

More reflective of complex nuclear reality than either, the collective model devised by Aage Bohr and his coworkers embraced a greater range of phenomena, including nuclear deformations, vibrations and rotations.

Niels Bohr died in 1962 at 77. The next year, Aage Bohr succeeded him as head of the Institute of Theoretical Physics in Copenhagen, which was later named for his father.

Aage Bohr's Nobel came in 1975 and was shared with the other creators of the collective model, Mottelsson and Leo James Rainwater of the United States.

Mr. Bohr's first wife, Marietta Soffer Bohr, died in 1978.

Survivors include his wife of 28 years, Bente Meyer Bohr; and three children from his first marriage.

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