Hess, Victor Franz (1883-1964), an Austrian-born physicist, won the 1936 Nobel Prize for physics for his discovery of cosmic radiation, radioactivity that arrives on Earth from outside the atmosphere. He shared the prize with American physicist Carl David Anderson , who was honored for his discovery of the positron.
Hess (also known as Victor Francis), was born in Waldstein Castle in Steiermark, Austria, the son of a forester in the service of Prince Ottingen-Wallerstein. Hess enrolled in Graz University from 1901 and he obtained his Ph.D. there in 1906. He held several positions at the University of Vienna before he began studying radioactivity at the university’s Institute of Radium Research in 1910.
Radioactive materials, such as radium, emit radiation of high-energy particles and waves that ionize atoms in the air. In ionization radiation knocks negatively charged electrons from some of the atoms, leaving a positively charged atom that is called an ion. Hess studied this process and the natural ionization that constantly occurs in the atmosphere. Some atmospheric ionization is due to the radioactivity of the Earth’s rocks, but scientists suspected that some of it was caused by radiation from another source. Hess took instruments up mountains, and then with him on balloon flights. He found that the greater the height above sea level, the greater the ionization. His experiments showed that the radiation causing the ionization must come from outside Earth. The origin of this cosmic radiation was completely unknown at that time. Scientists now believe that some cosmic radiation comes from the sun, but that most comes from violent events far away such as supernova explosions. Some of it comes from beyond the galaxy.
In 1920, Hess became professor of experimental physics at Graz University. From 1921 to 1923, he worked in the United States. He then returned to Graz and continued to study radioactivity and atmospheric ionization. In 1931, he became professor of physics at the University of Innsbruck where he founded a high-altitude station in the Alps for the study of cosmic rays. He emigrated to the United States in 1938 and was professor of physics at Fordham University in New York City until 1956. He became a U.S. citizen in 1944.
