Our inaugural post in the Hump-Day History series is a subject that is a touchstone to those who have studied the history of physics, but that does not feature in the top tier of popular knowledge of the history of science. This is a short-lived but stinging moment in the history of physics in Germany from the 1930s known in English as “Aryan physics” but in German as deutsche Physik, or “German physics”. The reason “Aryan” tends to be used is because “deutsche” had a very ethnic connotation that served to distinguish this style of physics from what the proponents of deutsche Physik considered to be “Jewish” physics, by which they meant relativity and quantum mechanics, the subjects that had over the prior two decades catapulted German physics to a clear position at the forefront of the profession.
Philipp Lenard receives an honorary degree from Heidelberg University. Credit: AIP Emilio Segre Visual Archives, Physics Today Collection
Deutsche Physik proponents were generally physicists who sought to benefit from the takeover of the Nazi Party in 1933. They were led by Nobel laureates Philipp Lenard (Nobel, 1905) and Johannes Stark (1919). After the Nazis took power, new civil service laws banned most Jews from government service, which included research posts in universities and important institutions like the Kaiser Wilhelm (now Max Planck) Institutes. By painting the highly abstract and philosophically unintuitive nature of recent physical theory as characteristically Jewish, Lenard et al attempted to tar non-Jewish physicists who had been a part of the new wave in physics as intellectual enemies of the German state and people. Their main weapon was to use the Nazi state apparatus to install their allies in prominent university posts, thereby squelching new styles of theory and clearing additional space for a more familiar style of physics now branded as characteristically and ethnically “German”, which favored mathematical interpretations of experimental work that were grounded in theories of physical instrumentation and “intuitive” principles.
The deutsche Physik proponents’ most prominent target (aside from Einstein, who had emigrated) was Werner Heisenberg, one of the central figures in the quantum mechanics revolution and a key proponent of radical philosophical interpretations of the new physics. In 1937, they denounced him in Das Schwarze Korps, the journal of the SS, labeling him a “white Jew”. Their continued harassment put him in political danger and cost him a promotion to Arnold Sommerfeld’s chair at the University of Munich. However, in one of the stranger turns in the history of physics, it happened that Heisenberg’s mother knew SS-head Heinrich Himmler’s mother, who persuaded her son to have Heisenberg’s case specially investigated, leading to the clearing of his name a year later. Notoriously, the Nazis would later make use of Heisenberg as the head of their nuclear research project. Meanwhile, Heisenberg’s clearance signaled the end of whatever influence Lenard, Stark, and their followers managed to achieve on the coattails of Nazi antisemitism and oppression.
The long-term impact of the deutsche Physik movement is questionable. Symbolically, it ranks with Lysenkoism as a case-in-point of the dangers of crass ideological influence in science, but the civil service laws were the first and worst blow against the status of German physics.
The key work is Alan Beyerchen’s Scientists Under Hitler: Politics in the Physics Community in the Third Reich (1977). Also see David Cassidy’s essential biography of Heisenberg entitled Uncertainty (1993). Other works on physics and other mainstream science in the early Nazi era are John Heilbron’s biography of Max Planck, entitled Dilemmas of an Upright Man (1986), and Kristie Macrakis’ look at the Kaiser Wilhelm Society under Hitler, Surviving the Swastika: Scientific Research in Nazi Germany (1993). Also, Mark Walker has written extensively on the German scientific community under the Nazis, particularly on the German nuclear project.
Finally, see this cartoon.