Philipp Lenard
Philipp Eduard Anton von Lenard (June 7, 1862 – May 20, 1947) was a German physicist and the winner of the Nobel Prize for Physics in 1905 for his research on cathode rays and the discovery of many of their properties.Lenard is remembered as strong nationalist who despised English physics, which he considered as having stolen their ideas from Germany. During the Nazi time he was the outspoken proponent of the idea that Germany should rely on "Deutsche Physik" (best translated as "Aryan physics") and ignore the (in his opinion) fallacious and maybe even deliberately misleading ideas of "Jewish physics" (by which he meant chiefly the theories of Albert Einstein).
One might argue that nationalism and anti-Semitism is already bad enough but many physicists feel it to be even more tainting and embarrassing that Lenard tried to attack a theory not by means of scientific argument but by arguing ad hominem. It is hence sort of amusing to remark in this context the important role that Einstein's explanation of the photoelectric effect plays for appreciating the value of Lenard's work on cathode rays: without Einstein's theory demonstrating the importance of Lenard's observation, he might not have been awarded a Nobel prize.