Physicist (theoretical physics; general theory of relativity; quantum mechanics; studies in Cracow (W. Natanson) and Berlin (M. von Laue); professor in Lwow; Institute for Advanced Studies (Princeton, N. J. USA), 1936-1950; Toronto University, 1938-1940; Warsaw University, 1950-1968. Publications: Foundations of the New Field Theory (Born, Infeld), 1934; The Gravitational Equations and the Problem of Motion (with A. Einstein and B. Hoffmann), 1938-1940; On the Motion of Bodies in General Relativity Theory, 1954.