Patrick Blackett

Patrick Maynard Stuart Blackett, Baron Blackett, (18 November 1897 – 13 July 1974), was a British experimental physicist known for his work on cloud chambers, cosmic rays, and paleomagnetism, awarded the Nobel Prize in Physics in 1948.

In August 1914 on the outbreak of World War I Blackett was assigned to active service as a midshipman.

He was transferred to the Cape Verde Islands on HMS Carnarvon and was present at the Battle of the Falkland Islands.

He was then transferred to HMS Barham and saw much action at the Battle of Jutland.

While on HMS Barham, Blackett was co-inventor of a gunnery device on which the Admiralty took out a patent.

In 1916 he applied to join the RNAS but his application was refused.

In October that year he became a sub-lieutenant on HMS P17 on Dover patrol, and in July 1917 he was posted to HMS Sturgeon in the Harwich Force under Admiral Tyrwhitt.

Blackett was particularly concerned by the poor quality of gunnery in the force compared with that of the enemy and of his own previous experience, and started to read science textbooks.

He was promoted to lieutenant in May 1918, but had decided to leave the Navy.

Then, in January 1919, the Admiralty sent the officers whose training had been interrupted by the war to the University of Cambridge for a course of general duties.

On his first night at Magdalene College, Cambridge, he met Kingsley Martin and Geoffrey Webb, later recalling that he had never before, in his naval training, heard intellectual conversation.

Blackett was impressed by the prestigious Cavendish Laboratory, and left the Navy to study mathematics and physics at Cambridge.

After graduating from Magdalene College in 1921, Blackett spent ten years working at the Cavendish Laboratory as an experimental physicist with Ernest Rutherford and in 1923 became a fellow of King's College, Cambridge, a position he held until 1933.

Rutherford had found out that the nucleus of the nitrogen atom could be disintegrated by firing fast alpha particles into nitrogen.

Blackett spent some time in 1924–1925 at Göttingen, Germany, working with James Franck on atomic spectra.

In 1925 he became the first person to prove that radioactivity could cause the nuclear transmutation of one chemical element to another.

He also made a major contribution in World War II advising on military strategy and developing operational research.

He asked Blackett to use a cloud chamber to find visible tracks of this disintegration, and by 1925, he had taken 23,000 photographs showing 415,000 tracks of ionized particles.

Eight of these were forked, and this showed that the nitrogen atom-alpha particle combination had formed an atom of fluorine, which then disintegrated into an isotope of oxygen 17 and a proton.

Blackett published the results of his experiments in 1925.

He thus became the first person to deliberately transmute one element into another.

During his time at Cambridge, he became the supervisor of the young American graduate J. Robert Oppenheimer.

Oppenheimer's desire to study theoretical physics rather than focus on lab work brought him into conflict with Blackett.

While seeking help for a psychiatric breakdown induced by the demanding Blackett, Oppenheimer admitted to trying to poison his tutor with an apple laced with toxins.

Blackett did not eat the apple and no action was taken over the attempted poisoning.

In 1932, working with Giuseppe Occhialini, he devised a system of Geiger counters which took photographs only when a cosmic ray particle traversed the chamber.

They found 500 tracks of high energy cosmic ray particles in 700 automatic exposures.

In 1933, Blackett discovered fourteen tracks which confirmed the existence of the positron and revealed the now instantly recognisable opposing spiral traces of positron/electron pair production.

This work and that on annihilation radiation made him one of the first and leading experts on antimatter.

That year he moved to Birkbeck, University of London, as professor of Physics for four years.

Then in 1937 he went to the Victoria University of Manchester where he was elected to the Langworthy Professorship and created a major international research laboratory.

His views saw an outlet in third world development and in influencing policy in the Labour government of the 1960s.

Blackett was born in Kensington, London, the son of Arthur Stuart Blackett, a stockbroker, and his wife Caroline Maynard.

His younger sister was the psychoanalyst Marion Milner.

His paternal grandfather Rev. Henry Blackett, brother of Edmund Blacket the Australian architect, was for many years vicar of Croydon.

His maternal grandfather Charles Maynard was an officer in the Royal Artillery at the time of the Indian Mutiny.

The Blackett family lived successively at Kensington, Kenley, Woking and Guildford, Surrey, where Blackett went to preparatory school.

His main hobbies were model aeroplanes and crystal radio.

When he went for interview for entrance to the Royal Naval College, Osborne, Isle of Wight, Charles Rolls had completed his cross-channel flight the previous day and Blackett who had tracked the flight on his crystal set was able to expound lengthily on the subject.

He was accepted and spent two years there before moving on to Dartmouth where he was "usually head of his class".