Walther BotheDied 8 Feb 1957 at age 66 (born 8 Jan 1891).Walther Wilhelm Georg Franz Bothe was a German physicist who developed the coincidence method of detecting the emission of electrons by x-rays in which electrons passing through two adjacent Geiger tubes at almost the same time are registered as a coincidental event. He used it to show that momentum and energy are conserved at the atomic level. In 1929 he applied the method to the study of cosmic rays and was able to show that they consisted of massive particles rather than photons. This research brought him a share (with Max Born) in the Nobel Prize for 1954. In 1930, he observed a strange radiation emitted from beryllium when it was exposed to alpha particles, later identified by Chadwick as consisting of neutrons. He built Germany's first cyclotron (1943). |
