Hess, Victor Francis, 1883–1964, American physicist, b. Austria, Ph.D. Univ. of Graz, 1906. After teaching at the universities of Graz and Innsbruck, he came to the United States in 1938 and was later naturalized. He became professor of physics at Fordham in 1938. By means of instruments carried aloft in balloons, Hess and others proved that radiation that ionizes the atmosphere is of cosmic origin. For this discovery of cosmic rays he shared with C. D. Anderson the 1936 Nobel Prize in Physics. He attributed (1939) a 27-day cycle of cosmic-ray intensity to the magnetic field of the sun and correlated it with the 27-day period of rotation of the sun. He also worked on devising methods for detecting minute quantities of radioactive substances. His works include Cosmic Radiation and Its Biological Effects (with Jakob Eugster, 1940, 2d ed. 1949).