Otto Hahn

Otto Hahn (March 8, 1879 – July 28, 1968) was a German radiochemist and pioneer in nuclear science whose work fundamentally transformed 20th-century physics and technology. After studying chemistry and physics, Hahn conducted groundbreaking research on radioactive elements, initially working with Ernest Rutherford at McGill University. In 1938, working with Fritz Strassmann and with theoretical insights from Lise Meitner and Otto Frisch, Hahn discovered nuclear fission—the splitting of atomic nuclei that releases enormous energy. This discovery was revolutionary, explaining how uranium could be split into lighter elements while releasing vast amounts of energy, and it provided the scientific foundation for both nuclear power generation and atomic weapons. Hahn was awarded the Nobel Prize in Chemistry in 1944 for this discovery. During and after World War II, Hahn became deeply troubled by the military applications of his work, particularly the atomic bombs dropped on Japan. After the war, he became an advocate for peaceful uses of nuclear energy and a prominent voice for nuclear disarmament and international cooperation in science. He spent his later years as director of the Max Planck Institute, promoting scientific research and ethical responsibility in the atomic age.