In 1913 he married Kate Hirschberg . After finishing his thesis under the direction of Paul Koebe at the University of Göttingen in 1910 and gaining his doctorate ( PhD ) , he became assistant at the Observatory in Berlin , where he became associated with Albert Einstein . During an expedition to verify general relativity during a solar eclipse in 1914 , World War I broke out and he was interned in Russia , for a few days , before being freed in an exchanging of prisoners . The expedition failed . After the war , he was engaged in the construction of a solar observatory in Potsdam , the '' Einsteinturm '' , and he was director of the Einstein-Institut . In 1933 Hitler came to power and Freundlich was forced to leave Germany ; he had a Jewish grandmother and his wife was Jewish . He was appointed professor at the University of Istanbul , which was reformed by Kemal Atatürk with the help of many German scholars . In 1937 he left Istanbul to take up the post of professor of astronomy at the Charles University of Prague , but this appointment was terminated by the German occupation
solar eclipse in 1914
Solar eclipse of August 21, 1914
Erwin Finlay-Freundlich