Otto Hahn was born the son of master glazier and merchant Heinrich Hahn in Frankfurt am Main on 8 March 1879. The youngest of four brothers, whose father actually wanted him to be an architect, Hahn went on to study chemistry at the universities of Marburg and Munich after completing his schooling in his home town. He received his doctorate in 1901 under Theodor Zincke at Marburg with a dissertation on organic chemistry (The bromine derivates of isoeugenol). He then completed his military service in 1901/02.
After two years as an assistant in Marburg (1902-1904) he went to England to work under Sir William Ramsay (1904/05). There he received an induction into the new field of radioactivity and discovered a radioactive substance, radiothorium. To further his education he went to Montreal, Canada, in the winter of 1905/06 where he worked under Ernest Rutherford. One of the discoveries he made there was another radioactive substance, radioactinium. On the strength of this work and on the suggestion of Sir William Ramsay, Otto Hahn decided to remain in the field of radium research and in 1906 went to work as an assistant at the University of Berlin's Institute of Chemistry under Professor Emil Fischer (until 1910). He obtained his postdoctoral lecturing qualification there in 1907 (without a thesis). In the meantime he had discovered another radioactive substance, mesothorium, which later became important as a substitute for the more expensive radium. In 1910 he became associate professor at the University of Berlin (until his resignation in 1934). From 1914 to 1918 he was an officer in the First World War, serving in Fritz Haber's chemical warfare unit, among other divisions.
Career in the KWG
As a Scientific Member, he joined the newly founded Kaiser Wilhelm Institute of Chemistry in Berlin-Dahlem in 1912, where he was head of a department. He was made Deputy Director of the Institute in 1924, served as Director between 1928 and 1945, and was also a Senator of the KWG until 1936. Hahn was then a Scientific Member of the MPI for Chemistry from 1949 to 1960. He worked in a spirit of close academic friendship with Dr. Lise Meitner from 1907 to 1938 (at the KWI from 1913), above all on beta rays; in 1918 they jointly discovered protactinium, and uranium Z in 1922. Otto Hahn was working with Fritz Strassmann in 1938 when they discovered uranium fission with neutrons. In exile in Sweden, Lise Meitner succeeded in finding the physical explanation and describing the discovery in conjunction with Otto R. Frisch. In 1945 Hahn was awarded the 1944 Nobel Prize for this discovery.
According to contemporary witnesses, Otto Hahn came through the Nazi era with his personal integrity intact. He spoke up in the strongest terms for Jewish colleagues and friends and helped some to flee or to survive the regime. Following Germany's defeat in the war, he was interred with other German scientists at Farm Hall in England. His institute in Berlin had been almost completely destroyed in 1944 and had been moved from Berlin to Tailfingen in Württemberg.
Hahn, whose integrity and academic achievements within the KWG made him a future leading figure, enjoyed substantial British support for his goal of rebuilding academic research in Germany. The Kaiser Wilhelm Society had been without a President since the death of Albert Vögler on 14 April 1945. The leadership of the Society in Göttingen had again been taken up by Max Planck in an acting capacity, and he wrote to Otto Hahn in England on 25 July 1945 asking if he would be prepared to accept the post of President as voted for by the Directors of all the Kaiser Wilhelm Institutes. Otto Hahn replied that he would, and upon his return to Germany assumed the office of President of the Kaiser Wilhelm Society in Göttingen on 1 April 1946 (a post he was to hold until 1951). At the same time – with the trust of the British Allied forces – he took on the task of expanding the KWG/MPG into all three western zones, starting from the British zone, thereby pushing forward the reconstruction of German science.
For him, this meant abandoning the rest of his scientific work at his institute and familiarising himself with an area that had been foreign to him until then. Never before in the history of the Society had a President taken up the reins of leadership at so critical a time and under such vast and impending difficulties. With great optimism he set to work, drawing on the Administrative Headquarters which had relocated to Göttingen under Dr. Ernst Telschow and buoyed by the trust of all the Institute Directors.
At the end of the war, it was not only a matter of ensuring that the various institutes could continue their work, it was about safeguarding the very existence of the Society. The Allied Control Council Law No. 25 on the control of scientific research dated 29 April 1946 restricted German scientists to basic research. Furthermore, the Americans wanted the Kaiser Wilhelm Society, as a Nazi organisation, to be disbanded by the Allied Control Council in Berlin for its part in activities vital to the war effort. However, a law to this effect never came about – the Cold War broke out.
The foundation of the Max Planck Society
The Max Planck Society was founded in Göttingen on 26 February 1948 to continue the work and the institutes of the Kaiser Wilhelm Society. Its Senate again elected Otto Hahn President. The Society experienced a renewed boom under his leadership. The old institutes were expanded and new ones founded, the financial situation improved, and efforts were made to gain academic respect at home and abroad. The total budget of the Max Planck Society had risen from 12 to 47 million by 1960, the number of institutes and research units had gone up from 21 (23) to 40, and the workforce had grown from 1,400 to almost 3,000 (840 of them scientists); the number of Supporting Members stood at 1,075.
The recognition of his achievements as President and the esteem in which Otto Hahn was held as a person came across clearly on 8 March 1959 at his 80th birthday celebrations in Göttingen and on 19 May 1960 in Bremen when he was made Honorary President and Honorary Senator at the 11th General Meeting of the Max Planck Society.