Otto Hahn (1879-1968), German physical chemist who received the Nobel Prize for Chemistry in 1944 for his discovery of the process of fission in uranium and thorium in 1938. Hahn's discovery of fission was made in collaboration with Lise Meitner and Fritz Strassmann. This fundamental discovery immediately contributed to the discovery of the nuclear chain reaction and the development of nuclear weapons and ultimately nuclear power.
With doctorate in hand from the University of Marburg in Germany, Hahn intended to make a career as an industrial chemist in a company with international business connections. He traveled to England to improve his English-language skills and found a job as a laboratory assistant at University College, London. Hahn quickly demonstrated his great skill as an experimentalist by isolating radioactive thorium. After working with Ernest Rutherford in Montreal, he joined the faculty of the University of Berlin.
Hahn, Meitner, and Strassmann were not engaged in nuclear weapons research during World War II. At the end of the war Hahn was astonished to hear that he had won the Nobel Prize for chemistry in 1944 and that nuclear bombs had been developed from his basic discovery. At the Nobel Prize awards ceremony, the chairman of the Nobel Committee for Chemistry announced, "Professor Hahn has informed us that he is regrettably unable to attend this ceremony"—the British, seeking information from him about the failed German effort to develop an atomic bomb, were holding him prisoner. In the post-war era, as director of the Max-Planck-Gesellschaft, Hahn publicly opposed the use of nuclear weapons.