Sir Mark Oliphant (1901-2000), Australian nuclear physicist and politician. He worked with Ernest Rutherford with whom he discovered tritium, an isotope of hydrogen, in 1934. Oliphant spent most of his life designing and building particle accelerators. During the Second World War he was in charge of the team that successfully developed microwave radar. In 1943 he moved to the USA to work on the Manhattan Project, to develop an atomic bomb. He left before the first bomb was dropped and spent the rest of his life campaigning against atomic weapons. In 1971 he was elected State Governor of South Australia, a post he held for five years.