Victor Hess

Victor F. Hess (June 24, 1883 to Dec 17, 1964) Hess was awarded the Nobel Prize in Physics in 1936 for discovering cosmic rays.  Before Hess did his pioneering work, it was assumed that the ionizing radiation measured in the atmosphere had a terrestrial origin and would thus decrease in intensity at higher altitudes. After improving the devices used to measure such radiation, Hess carried such devices up to altitudes as high as 5.3 km in a series of hazardous balloon flights undertaken in 1911-2 both at night and daytime. He found that the intensity of radiation did indeed decrease with height up to about 1 km, but then strongly increased with altitude, indicating a cosmic origin.  The physicist Carl D. Anderson gave the name “cosmic rays” to this radiation. Anderson discovered positrons (the anti-electrons predicted by Dirac’s theory of electrons) in cosmic rays in 1932, for which he shared in the 1936 Nobel Prize with Hess.  In 1936, Anderson and his student Seth Neddermeyer discovered muons in cosmic rays, the first particle to be discovered that is not a constituent of ordinary matter.  In 1938, Hess emigrated from his native Austria to the United States with his Jewish wife to escape Nazi persecution. He was a devout Catholic, and in 1946 wrote an article, “My Faith”, in which he discussed the relation of science and religion and explained why he believed in God.

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