Blackett, Patrick Maynard Stuart (1897-1974), a British physicist, made improvements to the Wilson cloud chamber, for which he received the Nobel Prize in physics in 1948. Blackett made important discoveries about particles and cosmic rays.

Blackett was one of three children and the only son of Arthur Stuart Blackett, a stockbroker, and Caroline Frances Maynard Blackett. As a boy, Blackett enjoyed learning about nature and especially wildlife. He enrolled at Osborne Royal Naval College in 1910 and Dartmouth Royal Naval College in 1912. He served as a naval cadet during World War I (1914-1918) and attained the rank of lieutenant. He resigned his commission in 1919 to pursue an education at Magdalene College, Cambridge University.

Blackett earned a B.A. degree in 1921 and started working at the Cavendish Laboratory, Cambridge, under the guidance of Ernest Rutherford, a leading physicist. After graduation, Blackett received a fellowship that allowed him to stay at Cambridge, where he began his investigations with the Wilson cloud chamber. To conduct his research, he used the chamber to photograph vapor trails.

In 1924, Blackett married Costanza Bayon. They had two children, a son and a daughter.

Blackett spent 1924 to 1925 in Germany, studying quantum physics with James Franck at the University of Göttingen. By 1924, he had examined at least 20,000 such photographic plates. His experiments showed that an element could be artificially transmuted into another, as had been predicted by Rutherford. He then returned to Cambridge.

Starting in 1932, Blackett and Giuseppe Occhialini, an Italian physicist, investigated cosmic rays. Using the cloud chamber, the two scientists confirmed the existence of the positron. They also demonstrated the existence of cosmic ray showers of paired positrons and electrons. For his work with the Wilson cloud chamber, Blackett won the Nobel Prize in physics in 1948.

In 1933, Blackett accepted a position as professor of physics at Birkbeck College, a part of the University of London. In the mid-1930's, he served on the Tizard Committee of the Air Ministry, which considered how to improve Britain's air defense system. In 1937, he was appointed Langworthy Professor of Physics at the University of Manchester. During World War II (1939-1945), Blackett stepped away from the laboratory and used his scientific skills to help his country's war efforts in a number of capacities. He served as scientific officer in the instrument section of the Royal Aircraft Establishment and scientific adviser to the Anti-Aircraft Command. In both his roles as scientific adviser to the British Coastal Command and as Director of Naval Operational Research at the Admiralty, he helped develop military strategies related to antisubmarine warfare.

Blackett was also a member of a committee known as MAUD, to advise the United Kingdom government on the feasibility of building an atomic bomb. When the committee submitted a report to the government urging the United Kingdom to enter the race to build an atomic bomb, Blackett was the only dissenting member. He believed it made more sense for the United Kingdom, which lacked sufficient funds to undertake such a project, to join the United States efforts to produce a bomb. In the end, the government decided in favor of Blackett's argument.

Following the war, Blackett spoke out against the atomic bomb and criticized the bombing of civilians in Germany and Japan. He expressed his opinions in the book Military and Political Consequences of Atomic Energy (1948). The book was not well received by the public, and the controversy from its publication overshadowed the Nobel Prize he won that year. Blackett continued to speak out against nuclear weapons for over a decade, despite heavy criticism. In the mid-1960's, many of his views became accepted and were incorporated into mainstream thought.

In 1953, Blackett accepted the position as head of the physics department of the Imperial College of Science and Technology in London, a post he retained until his retirement in 1965. After retirement, Blackett remained there as prorector and professor of physics. In 1965, he became president of the Royal Society.

In addition to the Nobel Prize, Blackett received the Royal Medal (1940) and the Copley medal (1956) of the Royal Society. He held numerous honorary degrees and was awarded the Order of Merit in 1967. Four years later, he became a life peer, Baron Blackett of Chelsea.