Celebiography.net

Viktor Hess

Picture of Viktor Hess

Date of Birth: 06/24/1883

Age: 81

Place of birth: Waldstein chateau

Citizenship: Austria

Who discovered cosmic rays?

After defending G. was going to do research on the optics of the University of Berlin under the direction of Paul Drude, but after the suicide of Drude was forced to change his plans. Operating demonstrator and lecturer at the Vienna University, became interested in research of Franz Exner and Egon von Schweidler on the ionizing effect of radioactive radiations. Such radiation arise when atoms unstable elements such as uranium or thorium emit "clots" (portions) of energy and positive or negative particles. Under the influence of radiation surrounding the source of the atmosphere becomes electrically conductive, ie, ionized. Such activity can be detected using an electroscope - the device which loses the electric charge communicated to him under the influence of radiation.

Working since 1910 as an assistant researcher at the Institute of radium research at Vienna University, he learned about his colleagues conducted experiments to determine the source of ionizing radiation in the atmosphere. He became known and that a few months earlier Theodor Wulf measured the ionization of the atmosphere in Paris. The measurements were made with a Wolfe Eiffel Tower and showed that on top of it (at an altitude of 320 m), the radiation level is much higher than at its base. These Woolf disagreed with the then existing theory that radiation could only go out of the ground. Wolfe suggested that unusually high levels of radiation at the top caused by radiation coming from the Earth`s atmosphere. He turned to the other scientists with a proposal to test his hypothesis, launching into the atmosphere via balloons measuring instruments.

The following year he created devices that can withstand significant changes in temperature and pressure during the ascent to high altitude. G. calculated that the maximum height at which the Earth`s radiation could ionize the atmosphere is equal to 500 m. It is with the help of the Austrian aeronautic club launched ten aerosondes the next two years. "I was able to show - he recalled later - that the ionization [in electroscope] decreased with increasing lifting height above the ground (by reducing the impact of radioactive substances in the ground), but starting from a height of 1000 m significantly increased and at an altitude of 5000 m reaches values surpassing observed on the Earth`s surface "several times. These data led him to the conclusion that ionization could be caused by the penetration of the earth`s atmosphere of an unknown radiation from outer space.

The fact that the radiation comes from outer space, and does not come from the Sun, G. convinced of the night starts, during which there was no reduction in radiation levels in the upper atmosphere. In 1925, the new radiation was named by the American physicist Robert A. Millikan "cosmic rays." Experiments G. drew attention to the cosmic rays of other physicists, including Carl D. Anderson discovered the positron, a positively charged particle with a mass equal to the mass of an electron. He also, together with SH Neddermeyerom opened mu-meson - an unusually short-lived particle with a mass of about 200 times the mass of the electron. Later it became known as the muon.

In 1919 he was appointed assistant professor of physics at the University of Vienna, but in 1920 he moved to Graz, where he became an associate professor of experimental physics. In 1921, taking a vacation, he went to the United States, where he headed a research laboratory of the United States Radium Corporation in Orange (New Jersey) and also served as a consultant to the Mining Ministry of Internal Affairs of the United States Bureau.

In Graz, he returned in 1923. Two years later he became a full professor, and in 1929 was appointed dean of the faculty. In 1931, he became professor of experimental physics and director of the Institute of Radiation Research at the University of Innsbruck. He created a Hafelekar station on the study of cosmic rays.

For the "discovery of the cosmic rays", together with Carl D. Anderson was awarded the 1936 Nobel Prize in Physics, the Introducing the winners, Hans Pleyel from the Royal Swedish Academy of Sciences said that G. "offered us a new and important issues related to the formation and destruction substance problems, open up new areas to explore. "

In 1938, two months after Nazi Germany annexed Austria, G. was dismissed from his position in Graz, because his wife was Jewish, and he was scientific adviser to the government of the deposed Austrian Chancellor Kurt von Schuschnigg. After receiving a warning of the impending arrest, G. fled to Switzerland.

Invitation from Fordham University in 1938 led by G. and his wife in New York. At Fordham he taught physics, and six years later became an American citizen. In 1946 he was approached with the request to lead the world`s first-level radioactive fallout measurement in the United States dropped the atomic bombing of Hiroshima. The following year, together with the physicist William T. Makniffom developed a method for detecting small amounts of radium in the human body for measurement of gamma radiation.

In 1920, he married Bertha Marie Warner Breyski, who died in 1955. In the same year, married Elizabeth M. H

Pictures of Viktor Hess more

Viktor Hess picture
Viktor Hess photo