Philipp E. A. Lenard was a brilliant experimental physicist who made important contributions to the study of the photoelectric effect , the characterization of cathode rays, the nature of phosphorescence , ionization potentials, and other phenomena. He was awarded the 1905 Nobel Prize in physics primarily for his work on cathode rays. He taught and carried on research at a number of German universities, including Heidelberg, Bonn, Breslau, and Kiel, as well as at the Technische Hochschule in Aachen. In spite of his gifts as an experimentalist, Lenard is also remembered as an anti-Semite and enthusiastic proponent of National Socialism. His unwillingness to embrace many of the new developments in science taking place in the 1920s and 1930s is thought to be at least partially due to his political feelings that these ideas were false pronouncements from "Jewish science." By the end of his life, Lenard had lost the personal respect...