Isidor Rabi. Portrait of Isidor Isaac Rabi (1898- 1988), Austrian-American scientist. Inspired by Otto Stern, Rabi invented molecular-beam magnetic resonance methods for observing spectra. This worked by using a radio wave of the right frequency to flip excited molecules from one magnetic state to another. This allowed the theory of quantum electrodynamics to be tested by measuring the magnetic moment of an electron. His method became the basis of the nuclear magnetic resonance method and has also been applied to the maser, laser and atomic clock. In 1944 Rabi won the Nobel Prize for physics. Rabi later helped to found CERN, a high-energy physics laboratory.