Rudolf Fleischmann

German nuclear physicist (1903–2002)

Rudolf Fleischmann (1 May 1903 – 3 February 2002) was a German experimental nuclear physicist from Erlangen, Bavaria. He worked for Walther Bothe at the Physics Institute of the University of Heidelberg and then at the Institute for Physics of the Kaiser Wilhelm Institute for Medical Research. Through his association with Bothe, he became involved in the German nuclear energy project, also known as the Uranium Club; one of Fleischmann's areas of interest was isotope separation techniques. In 1941 he was appointed associate professor of experimental physics at the newly established Reichsuniversität Straßburg, in France. Late in 1944, he was arrested under the American Operation Alsos and sent to the United States. After he returned to Germany 1946, he became Director of the State Physical Institute at the University of Hamburg and developed it as a center of nuclear research. In 1953, he took a position at the University of Erlangen and achieved emeritus status in 1969. He was a signatory of the Göttingen Manifesto in 1957.

From 1922 to 1926, Fleischmann studied at the Friedrich Alexander Universität Erlangen Nürnberg and the Ludwig Maximilians Universität München. He received his doctorate in 1929 under Bernhard Gudden, director of the Physics Institute at Erlangen; the subject of his thesis was on the photoelectric effect in solid state physics.

In 1931, Fleischmann became a teaching assistant to Robert Pohl, director of the I. Physikalische Institut (First Physics Institute) at the Georg August Universität Göttingen. There he continued his work on solid state physics. even though its two most prominent supporters were the Nobel Laureates in Physics Philipp Lenard and Johannes Stark. Supporters of deutsche Physik launched vicious attacks against leading theoretical physicists. While Lenard was retired from the University of Heidelberg, he still had significant influence there. In 1934, Lenard had managed to get Bothe relieved of his directorship of the Physical and Radiological Institute at the University of Heidelberg, whereupon Bothe was able to become the Director of the Institut für Physik of the KWImF, replacing Karl W. Hauser, who had recently died. Ludolf von Krehl, Director of the KWImF, and Max Planck, President of the Kaiser Wilhelm Society (KWG, Kaiser Wilhelm Society, today, the Max Planck Society), had offered the directorship to Bothe to ward off the possibility of his emigration. Fleischmann went with Bothe and worked with him there until 1941. Bothe was a principal in the German nuclear energy project, also known as the Uranverein (Uranium Club), and Fleischmann was brought into the project through his affiliation with Bothe. Fleischmann worked on isotope separation techniques. During the period in which deutsche Physik was gaining prominence, which started right after Adolf Hitler came to power in 1933, a foremost concern of many scientists in Germany was to maintain autonomy against political encroachment. Some of the more established scientists, such as Max von Laue, could demonstrate more autonomy than the younger and less established scientists. This was, in part, due to political organizations, such as the Nationalsozialistischer Deutscher Dozentenbund (NSDDB, National Socialist German University Lecturers League), whose district leaders had a decisive role in the acceptance of an Habilitationsschrift, which was a prerequisite to attaining the rank of Privatdozent necessary to becoming a university lecturer. While some with ability joined such organizations out of tactical career considerations, others with ability and adherence to historical academic standards joined these organizations to moderate their activities. This was the case of Wolfgang Finkelnburg. It was in the summer of 1940 that Finkelnburg became an acting director of the NSDDB at Technische Hochschule Darmstadt. As such, he organized the Münchner Religionsgespräche, which took place on 15 November 1940 and was known as the "Munich Synod". The Münchner Religionsgespräche was an offensive against deutsche Physik. While the technical outcome may have been thin, it was a political victory against deutsche Physik. By the time the American Operation Alsos forces had entered Strasboug in late November 1944, von Weizsäcker had already escaped back to Germany. Fleischmann was arrested by the Alsos forces and incarcerated in a local jail until Samuel Goudsmit, chief scientific advisor to Operation Alsos, arrived and made other arrangements for his incarceration. Fleischmann was sent to the United States for interrogation on the Uranverein and to exploit his scientific expertise in nuclear and atomic physics. After Fleischmann's return to Germany in 1946, he accepted the appointment to the Lehrstuhl für Experimentalphysik (Chair for Experimental Physics) at the University of Hamburg and he became Director of the Physikalische Staatsinstitut (State Physical Institute) and ordinarius professor (ordentlicher Professor) for experimental physics. Initially, due to restrictions by the Allied occupying powers in Germany, nuclear research was forbidden. During this time, Fleischmann developed a new method for determining the optical constants of thin metal layers. As the Cold War developed, this restriction was eased and Fleischmann was able to make the University of Hamburg a center for nuclear physics research. This was done with the able assistance of colleagues such as Erich Bagge, H. Neuert, and Rodolf Kollath. In 1953, Fleischmann became an ordinarius professor at the University of Erlangen Nuremberg. He achieved emeritus status in 1969.