Born in Odessa. Studied at Leningrad University, then trained in Göttingen, Copenhagen (under Niels Bohr), and Cambridge (under Ernest Rutherford). In 1933, disillusioned with the Soviet regime, he made a daring escape with his wife — first attempting to cross the Black Sea by kayak, then crossing the border into Turkey. Settled in the USA, worked at George Washington University, then at the University of Colorado Boulder. He actively popularized science, writing a series of books about Mr. Tompkins. Awarded the Kalinga Prize by UNESCO.