 In 1945 , Rabi delivered the Richtmyer Memorial Lecture , held by the American Association of Physics Teachers in honor of Floyd K. Richtmyer , wherein he proposed that the magnetic resonance of atoms might be used as the basis of a clock . William L. Laurence wrote it up for the New York Times , under the headline " ' Cosmic pendulum ' for clock planned " . Before long Zacharias and Ramsey had built such atomic clocks . Rabi actively pursued his research into magnetic resonance until about 1960 , but he continued to make appearances at conferences and seminars until his death . 
