Niels Bohr

Name at birth: Niels Henrik David Bohr

Niels Bohr was the Danish physicist whose investigations of atomic structure earned him the 1922 Nobel Prize for physics. Bohr's work helped solve the problems classical physics could not explain about the nuclear model of the atom. He postulated that electrons moved in fixed orbits around the atom's nucleus, and he explained how they emitted or absorbed energy. Bohr attended the University of Copenhagen (1903-11), then studied for a time under Ernest Rutherford in Manchester, England. By 1916 he was back at the University of Copenhagen as a professor of physics, and in 1920 he became the first director of the Institute of Theoretical Physics. Bohr's Institute became a gathering place for the world's top physicists, and he is considered one of the foremost scientists of modern physics, along with Albert Einstein, Erwin Schrödinger and Enrico Fermi. During World War II Bohr avoided Adolf Hitler's army and left Denmark in 1943; he ended up in the United States and was sent to Los Alamos, New Mexico to join Robert Oppenheimer and others working to develop the atomic bomb. After the war he returned to Denmark and spent the rest of his career advocating the peaceful uses of atomic energy.