William George Penney, Baron Penney, (24 June 19093 March 1991) was an English mathematician and professor of mathematical physics at the Imperial College London and later the rector of Imperial College London. He had a leading role in the development of High Explosive Research, Britain's clandestine nuclear programme that started in 1942 during the Second World War which produced the first British atomic bomb in 1952. As the head of the British delegation working on the Manhattan Project at Los Alamos Laboratory, Penney initially carried out calculations to predict the damage effects generated by the blast wave of an atomic bomb. Upon returning home, Penney directed the British nuclear weapons directorate, codenamed Tube Alloys and directed scientific research at the Atomic Weapons Research Establishment which resulted in the first detonation of a British nuclear bomb in Operation Hurricane in 1952. After the test, Penney became chief advisor to the new United Kingdom Atomic Energy Authority (UKAEA). He was later chairman of the authority, which he used in international negotiations to control nuclear testing with the Partial Nuclear Test Ban Treaty. Penney's notable scientific contributions included the mathematics for complex wave dynamics, both in shock and gravity waves, proposing optimisation problems and solutions in hydrodynamics (which plays a major role in materials science and metallurgy.) During his later years, Penney lectured in mathematics and physics; he was the Rector of Imperial College London 1967–1973. Early life and education William George Penney was born in Gibraltar on 24 June 1909, the oldest child and only son of William Alfred Penney, a sergeant-major in the British Army's Ordnance Corps who was then serving overseas, and Blanche Evelyn Johnson, who had worked as a cashier before her marriage. His parents moved about frequently, but Penney did not always accompany them. After the outbreak of the First World War, Penney, his mother and his sisters moved to Sheerness, Kent, where he went to primary school. He then attended a school near Colchester, and finally, was at Sheerness Technical School for Boys from 1924 to 1926, where he displayed a talent for science. He participated in boxing and athletics, winning the school's dash. He also played cricket, and he was centre-forward on the school football team. In 1927, Penney's passion for science landed him in a local science laboratory where he worked for 10 shillings a week () as a laboratory assistant. This helped him to