Philipp Eduard Anton Lenard (7.06.1862—20.05.1947) was a German physicist and a member of the Berlin Academy of Sciences. He was born in Pressburg (now Bratislava). He studied at the universities of Budapest, Vienna, Berlin and Heidelberg. In 1887 — 94 he worked at the universities of Heidelberg and Bonn, in 1894 at the University of Breslau and in 1895 at the Higher Technical School in Aachen; in 1896-98 and 1907-30 he was professor at the University of Heidelberg and in 1898—1907 at the University of Kiel.
His work was in the field of optics and of atomic and molecular physics. He studied the phenomena of capillarity, phosphorescence, the ionisation of gases and the photoelectric effect, as well as cathode rays and the structure of the atom. He was one of the first to study the passage of cathode rays through thin metal plates, using a cathode tube with a thin window that he designed (1892) (the Lenard window), and he established many properties of these rays (Nobel Prize, 1905). He proved that electrons are released in the external photoelectric effect (1899) and that the energy of the emitted photoelectrons does not depend on the intensity of the incident light but is directly proportional to its frequency (1902). From the results of his own experiments on the scattering and absorption of cathode rays in matter he proposed in 1903 the so-called dynamide model of the atom.
He actively opposed relativity and sought to claim for himself priority in the discovery of X-rays. During the years of the Hitler regime he was an ardent Nazi.