Isidor Isaac Rabi | Biography

Born in Austro-Hungary (now Poland), Rabi emigrated with his family to the United States when he was very young. He grew up in New York City and Brooklyn, and attended orthodox Jewish schools. Although his parents intended him to become a rabbi, Rabi developed an interest in science; when he was eleven, he built a neighborhood telegraph system. He enrolled in the Manual Training High School in Brooklyn, where his outstanding grades earned him a full tuition scholarship to Cornell University. Beginning as an electrical engineering student, Rabi switched majors and graduated in 1919 with a B.A. in chemistry. He returned to Cornell in 1922, intending to continue his chemistry studies. However, Rabi again switched disciplines as well as schools; in 1923 he moved to Columbia University, and received his Ph.D. in physics in 1927. His dissertation concerned the measuring of the magnetic properties of molecules--a study he would continue to pursue throughout his career.

After earning his doctorate, Rabi spent a few years in Europe working with such acclaimed scientists as Erwin Schrödinger, Niels Bohr and Otto Stern (1888-1969). It was Stern's work on molecular structure that most inspired Rabi, and upon his return to Columbia (where he had been given a faculty position), he began his own experiments.

The Stern technique involved the creation of a beam of atoms or molecules by vaporizing a sample of silver. The vaporized silver was shot through a series of slits and then passed through a magnetic field. This technique revealed that electron s possess a property called spin, which, if measured accurately, might reveal much about the nature of the atom. Rabi began his research by first repeating and confirming Stern's technique, and then he strove to make it more precise. In 1937, he found that the application of a low-level radio signal would make the atoms reverse their spin, and that the frequency of the signal at that time was the key to a more accurate measurement. Initially, Rabi's measurements were only 10 times as precise as those made with Stern's technique, but he later improved his method to achieve 1,000 times the precision of Stern's results. The ability to accurately measure the magnetic properties of atoms was critical to the emerging science of nuclear physics.

During World War II, Rabi (like most other American scientists) lent his talents to the government. As associate director of the Massachusetts Institute of Technology Radiation Laboratory, he and his group were instrumental in the development of microwave emitters for radar systems. He served as a consultant to J. Robert Oppenheimer and was present at the first atomic bomb test at Alamogordo, New Mexico.

Rabi was awarded the 1944 Nobel Prize in physics for his precise method of "recording the magnetic properties of atomic nuclei."