Marcus Laurence Elwin Mark Oliphant

Marcus Laurence Elwin Mark Oliphant (1901-2000) was an Australian physicist and humanitarian who played an important role in the first experimental demonstration of nuclear fusion and also the development of nuclear weapons. He was born in Adelaide, South Australia, in 1901, and graduated from the University of Adelaide with degrees in mathematics, physics, and engineering. He then studied at the University of Cambridge's Cavendish Laboratory under Sir Ernest Rutherford, where he used a particle accelerator to fire heavy hydrogen nuclei (deuterons) at various targets. He discovered the respective nuclei of helium-3 (helions) and of tritium (tritons). He also discovered that when they reacted with each other, the particles that were released had far more energy than they started with. Energy had been liberated from inside the nucleus, and he realised that this was a result of nuclear fusion. Oliphant left the Cavendish Laboratory in 1937 to become the Poynting Professor of Physics at the University of Birmingham. He attempted to build a 60-inch (150 cm) cyclotron at the university, but its completion was postponed by the outbreak of the Second World War in Europe in 1939. He became involved with the development of radar, heading a group at the University of Birmingham that included John Randall and Harry Boot. They created a radical new design, the cavity magnetron, that made microwave radar possible. Oliphant also formed part of the MAUD Committee, which reported in July 1941, that an atomic bomb was not only feasible, but might be produced as early as 1943. Oliphant was instrumental in spreading the word of this finding in the United States, thereby starting what became the Manhattan Project. Later in the war, he worked on it with his friend Ernest Lawrence at the Radiation Laboratory in Berkeley, California, developing electromagnetic isotope separation, which provided the fissile component of the Little Boy atomic bomb used in the atomic bombing of Hiroshima in August 1945. After the war, Oliphant returned to Australia as a professor and director of the Research School of Physical Sciences at the Australian National University. He expanded the research areas to include astronomy, mathematics, geophysics, theoretical physics, atomic and molecular physics, nuclear physics and particle physics. He also advocated for peaceful uses of nuclear energy and opposed nuclear testing. He became involved in various humanitarian causes, such as Aboriginal rights, education, environment and arts. He was appointed as Governor of South Australia from 1971 to 1976. He died in Switzerland in 2000 at the age of 98.