Victor Franz Hess
Hess, Victor Franz (1883-1964), an Austrian-born American physicist, won the 1936 Nobel Prize in physics for his 1912 discovery of cosmic rays. Hess shared the prize with the American physicist Carl David Anderson, who won for his 1932 discovery of the positron, an elementary particle in cosmic rays that is also known as a positive electron.
Victor Franz Hess was born at Waldstein Castle in Steiermark, Austria. He studied mathematics and physics at the University of Graz and received a doctorate in physics in 1906. He then went to the University of Vienna for advanced work.
In 1908, Hess became a lecturer in physics at Vienna Veterinary College In 1910. he joined the Institute for Radium Research, where from 1911 to 1913, he conducted the research for which he would later receive the Nobel Prize.
By 1910, scientists knew that the air is ionized (electrically charged), but they had yet to determine the source of this electrical radiation. Some researchers thought that gamma rays from rocks and soil were releasing electrically charged particles called ions into the air. Measurements taken in the air at the top of the Eiffel Tower in Paris showed that the ionization was too great to have reached that height from the ground One person went up in a hot air balloon to take measurements at higher altitudes, but failed to obtain any definitive readings.
Hess thought that the ionization could be coming from a source other than the ground, and he decided to make balloon flights to conduct tests himself. He first designed electroscopes that could withstand the high altitudes, and he then began his series of tests. Beginning in 1911, Hess made balloon flights reaching a height of about 17,500 feet (5,334 meters), or more than 3 miles (5 kilometers). He discovered that ionization at this height was many times greater than that near the earth's surface. He made his flights both at night and during the day, and one of them during a nearly total eclipse of the sun. The ionization was the same each time, which meant that the sun could not be the source of the radiation. Hess concluded that electrically charged rays of very high penetrating power originated in the upper atmosphere or beyond. The American physicist Robert Andrews Millikan named them cosmic rays in 1925.
In 1920, Hess became associate professor of experimental physics at the University of Graz. That year, he married Marie Bertha Warner Breisky. Hess took a leave of absence from the university, and from 1921 to 1923, he was chief physicist and director of a research laboratory that was built under his supervision for the United States Radium Corporation in New Jersey. Hess returned to the University of Graz in 1923 and became a full professor in 1925.
In 1931, Hess became professor of physics at the University of Innsbruck. There he founded a high-altitude station in the Alps for the study of cosmic rays.
In 1937, Hess returned to the University of Graz. In 1938, the Nazi government of Germany took over Austria. Hess was dismissed from his university post, both because he had been a representative of the sciences in the earlier independent Austrian government and because he was Roman Catholic and his wife was Jewish. The Nazis did not approve of either religion. Four weeks before they were scheduled to be arrested and sent to a concentration camp, Hess and his wife escaped to Switzerland. They moved to the United States later that year.
From 1938 until his retirement in 1956, Hess was a professor of physics at Fordham University in New York. He became a U.S. citizen in 1944. In 1946, Hess conducted tests from the Empire State Building for radioactive fallout and cosmic ray bombardment. In the 1950's, he participated in other studies of radioactive fallout from nuclear weapons tests. He concentrated on the biological effects of radioactivity from both cosmic radiation and nuclear testing.
Marie Hess died in 1955. Later that year, Hess married Elizabeth M. Hoenke, the nurse who had cared for his wife. Hess had no children. He died on Dec. 17, 1964.