Lenard, Philipp Eduard Anton (fēˈlĭp āˈdōärt änˈtōn lāˈnärt) [key], 1862–1947, German physicist, b. Bratislava. After serving as professor at the universities of Kiel (1898–1907) and Heidelberg (1896–98, 1907–31), he headed the Philipp Lenard Institute at Heidelberg. He was the first to cause cathode rays to pass from the interior of a vacuum tube through a thin metal window into the air, where they produce luminosity. For his research in this field he received the 1905 Nobel Prize in Physics. He is noted also for his work on the structure of the atom and for the discovery (1902), in connection with the photoelectric effect, that the velocity of electrons is independent of the intensity of the light that emits them.
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