Walter Gerlach Walt ( h ) er Gerlach ( 1 August 1889 – 10 August 1979 ) was a German physicist who co - discovered spin quantization in a magnetic field , the Stern - Gerlach effect . Education . Gerlach was born in Biebrich , Hessen - Nassau . He studied at the University of Tübingen from 1908 , and received his doctorate in 1912 , under Friedrich Paschen . The subject of his dissertation was on the measurement of radiation . After obtaining his doctorate , he continued on as an assistant to Paschen , which he had been since 1911 . Gerlach completed his Habilitation at Tübingen in 1916 , while serving during World War I . Career . From 1915 to 1918 , during the war , Gerlach did service with the German Army . He worked on wireless telegraphy at Jena under Max Wien . He also served in the Artillerie - Prüfungskommission under Rudolf Ladenburg . Gerlach became a Privatdozent at the University of Tübingen in 1916 . A year later , he became a Privatdozent at the Georg - August University of Göttingen . From 1919 to 1920 , he was the head of a physics laboratory of Farbenfabriken Elberfeld , formerly Bayer - Werke . In 1920 , he became a teaching assistant and lecturer at the Johann Wolfgang Goethe University of Frankfurt am Main . The next year , he took a position as extraordinarius professor at Frankfurt . It was in November 1921 that he and Otto Stern discovered spin quantization in a magnetic field , known as the Stern - Gerlach effect . In 1925 , Gerlach took a call and became an ordinarius professor at the University of Tübingen , successor to Friedrich Paschen . In 1929 , he took a call and became ordinarius professor at the Ludwig Maximilians University of Munich , successor to Wilhelm Wien . He held this position until May 1945 , when he was arrested by the American and British Armed Forces . From 1937 until 1945 , Gerlach was a member of the supervisory board of the Kaiser - Wilhelm - Gesellschaft ( KWG ) . After 1946 , he continued to be an influential official in its successor organization after World War II , the Max - Planck - Gesellschaft ( MPG ) . On 1 January 1944 , Gerlach officially became head of the physics section of the Reichsforschungsrat ( RFR , Reich Research Council ) and Bevollmächtigter ( plenipotentiary ) of nuclear physics , replacing Abraham Esau . In April of that year , he founded the " Reichsberichte für Physik " , which were official reports appearing as supplements to the " Physikalische Zeitschrift " . From May 1945 , Gerlach was interned in France and Belgium by British and American Armed Forces under Operation Alsos . From July of that year to January 1946 , he was interned in England at Farm Hall under Operation Epsilon , which interned 10 German scientists who were thought to have participated in the development of atomic weapons . Upon Gerlach ’ s return to Germany in 1946 , he became a visiting professor at the University of Bonn . From 1948 , he became an ordinarius professor of experimental physics and director of the physics department at the University of Munich , a position he held until 1957 . He was also rector of the university from 1948 to 1951 . From 1949 to 1951 , Gerlach was the founding president of the Fraunhofer - Gesellschaft , which promotes applied sciences . From 1949 to 1961 , he was the vice - president of the Deutsche Gemeinschaft zur Erhaltung und Förderung der Forschung ( German Association for the Support and Advancement of Scientific Research ) ; also known in short as the Deutsche Forschungs - Gemeinschaft ( DFG ) , previously the Notgemeinschaft der Deutschen Wissenschaft . In 1957 , Gerlach was a co - signer of the Göttingen Manifesto , which was against rearming the Federal Republic of Germany with atomic weapons . He died in Munich in 1979 .