Robert Wichard Pohl (10 August 1884 – 5 June 1976) was a German physicist at the University of Göttingen. Nevill Francis Mott described him as the "father of solid state physics".
Early years and education
Robert Wichard Pohl was born in Hamburg as the son of the naval engineer Eugen Robert Pohl and his wife Martha. She was the daughter of , founder of the private 'Dr. Wichard Lange School', and granddaughter of , who founded the first German kindergarten, together with Friedrich Fröbel.
After completing the Dr. Wichard Lange School, Pohl entered the 'Gelehrtenschule des Johanneums' in 1895 and obtained his Abitur. In the summer semester of 1903, he enrolled for studies of natural science at the University of Heidelberg. There, he met James Franck, who up until Franck's death in 1964 remained a close friend. In the winter semester of 1903, Pohl transferred to the University of Berlin, where he majored in physics. Beginning in the summer semester of 1904, he had already begun scientific work in the Physics Institute with Emil Warburg on the topic which became his doctoral thesis. His first publication dates from this period, motivated by Bernhard Walter of the Hamburg State Physical Laboratory, where Pohl worked during his vacations, in particular attempting to observe the diffraction of X-ray radiation.
Career up to World War I
In the summer of 1906, Pohl completed his doctorate (Dr. Phil.) and took an assistantship in Berlin, working as instructor in the physics teaching labs under Heinrich Rubens, the Institute's director. He published joint articles with James Franck on ionic mobility in gases and on the propagation velocity of X-rays. From 1909 onward, he carried out research on the normal and the selective photoelectric effect in metals, and from 1910 he worked with Peter Pringsheim, on, among other things, the technically important problem of the fabrication of metal mirrors. In 1910, his monograph on the remote transmission of images appeared, and in 1912 he completed the Habilitation. In an addendum, his Habilitation thesis contains a discussion of von Laue's discovery of X-ray diffraction.
Following his Habilitation, Pohl began giving lecture courses on experimental physics, which also motivated him to start acquiring a private collection of lecture-demonstration apparatus. He also performed demonstration experiments at the meetings of the Physical Society. By the outbreak of WW I, he had published 54 scientific articles and three books.
When war broke out, Pohl attempted unsuccessfully to volunteer for military service, but was refused for health reasons. His suggestion, together with Erich Regener, to set up and operate privately-funded diagnostic X-ray apparatus in two military reserve hospitals was gratefully accepted. In November 1914, he began cooperating with military radio operators on locating enemy transmission stations; this led to his appointment to a position as chief engineer with the rank of captain on the Board of Transport Examiners (VPK), which he held until the end of the war.
Professorship in Göttingen
In February 1916, Pohl received the offer of an associate professorship in Göttingen (as successor to Eduard Riecke), but due to the war, he was unable to accept the position until early 1919. In his baggage for the move to Göttingen were more than 40 boxes with apparatus for his lectures. Because of the offer of a professorship at the Technical University of Stuttgart in September 1919, Pohl was promoted to Full Professor in Göttingen in December 1920 and became director of the 1st Physical Institute there. In June, 1922, he was offered a position in Würzburg, which he also refused. Thus, he was a participant in the Golden Age of physics in Göttingen during the 1920s as one of the three full professors there, along with James Franck (director of the 2nd Physical Institute) and the theoretician Max Born.
On Christmas 1922, Pohl married Tussa Madelung, the sister of Erwin Madelung, who was a research assistant in Göttingen when Tussa moved there from Strasbourg with her family in May, 1920. Robert and Tussa had three children: Ottilie, Eleonore, and Robert Otto, later physics professor at Cornell University.