Photo from the Nobel Foundation archive.
Isidor Isaac Rabi
Born: 29 July 1898, Rymanow, Austria-Hungary (now Poland)
Died: 11 January 1988, New York, NY, USA
Affiliation at the time of the award: Columbia University, New York, NY, USA
Prize motivation: "for his resonance method for recording the magnetic properties of atomic nuclei."
Prize share: 1/1
Isaac Isidor Rabi was born into a Jewish family in what was then Austria, but the family emigrated to the U.S. when he was one year old. During almost his entire career, he was associated with Columbia University in New York. During World War II, Rabi took part in development of the atomic bomb. After the war he promoted peace and the limiting of nuclear weapons. He also played a significant role in establishing major research laboratories in Bookhaven and CERN. Isidor Isaac Rabi was married and had two daughters.
Protons and neutrons in nuclei act like small, rotating magnets. Atoms and molecules therefore align in a magnetic field. In 1938, Isaac Isidor Rabi passed a beam of molecules through a magnetic field. When the beam was exposed to radio waves, the direction of rotation could be changed, but only in certain stages, in accordance with quantum mechanics. When the atoms returned to their original positions, they emitted electromagnetic radiation with uniquely characteristic frequencies.