The American physicist Victor Francis Hess (1883-1964) shared the Nobel Prize in Physics for his discovery of cosmic rays.

Victor Francis (originally Franz) Hess was born on June 24, 1883, at Schloss Waldstein, Styria. He studied physics at the universities of Graz (1901-1905) and Vienna (1905-1908) and graduated as a doctor of philosophy at Graz in 1906. From 1910 to 1920 Hess was a lecturer at the Institute for Radium Research in the University of Vienna.

In 1900 C. T. R. Wilson proved that air is a slight conductor of electricity. Thereafter it was held that this property of the air was due to ionization by gamma rays emitted by radioactive substances in the air or in the earth. It was known that gamma rays are almost completely absorbed by 300 meters of air. To test the theory, balloon ascents were made between 1909 and 1911. Each showed that the ionization was too great to have been...