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Ernest Walton

1903–1995

 

Science has not always been seen as an area in which the Irish have been seen to be pre-eminent, but with Ernest Walton, one of Ireland's Nobel Prize winners, the idea is invalid.  Walton was at the leading edge of research into atomic energy, which has proved to be both the most contentious and most dangerous area of science in the twentieth century.

      When the first atomic bomb was exploded at Alamogordo, New Mexico, on 16th July 1945, it was the end result of what Walton had begun, and the beginning of a new era of danger, and of awesome responsibility, for the United States.  Such are the profound changes that a small-scale scientific inquiry can precipitate.

      With his colleague John D. Cockcroft, he achieved the first artificial disintegration of the atomic nucleus.  In simple language, they 'split the atom' and opened the way for the atomic and hydrogen bombs.

      Ernest Walton was born in Dungarvan, County Waterford, in October 1906.  His father was a Methodist minister, while his mother came from a Protestant family long established in Armagh.

      He was sent to the Methodist College in Belfast, where it quickly became clear that he had a talent for mathematics and science.  He went on to study at Trinity College in Dublin, where he took a bachelor's degree in 1926, and a further master's degree in 1934.

      In 1935 he went on to Cambridge, where he joined the Cavendish Laboratory, then led by Ernest Rutherford.  Though the Irish student was given little working space, he found congenial company in T.E. Alibone and John D. Cockcroft.  At Rutherford's suggestion, he first began work on an experiment to increase the velocity of electrons by spinning them in an electric field produced by a changing circular magnetic field as a method of nuclear disintegration.  The initial experiment was not a success, but it cleared the way for a more important one.

      The problems they faced were illuminated by the arrival of the Russian (later American) physicist George Gamow.  He had been working with Niels Bohr in Denmark, where he had worked on a wave mechanical theory of penetration of the particles.  His ideas opened the way for Walton and Cockcroft, and Rutherford gave them both permission, money, and space to continue.  With a budget of £1,000 they created the first accelerator for atomic particles.  Today the machine itself can be seen in the South Kensington Science Museum.  It now looks like an amateur relic of the past, which it is, but its importance was immense.

      It was on 13th April 1932 that Walton and Cockcroft found that their first experiment had been successful.  Walton's first observation of the telltale scintillations that marked the breakup of the nuclei were quickly confirmed by the pair.

      Their achievement was historic for several reasons.  It was the first time that scientists had produced a change in the atomic nucleus in a controlled situation.  In the process they had found a new, and seemingly boundless, source of energy.  They had confirmed Gamow's theory about the movement of particles, and also Einstein's theory that energy and mass are interchangeable.

      Their discovery was announced in a letter to the science journal Nature, and described at a meeting of the Royal Society in London on 15th June 1932.  The news created a sensation worldwide.  Their work inspired many other scientists with results that transformed scientific knowledge and the social life of the late twentieth century.

      In 1932 Walton received his Ph.D., and in 1934 he returned to his alma mater, Trinity College in Dublin.  In Dublin he was seen as a quite unflamboyant personality.  He was not given to small talk, a very Ulster-like characteristic.  He had married Freda Wilson, who had also been a student at the Methodist College, and they had two sons and two daughters.

      Walton was content to develop his department in the Dublin university, and in 1946 was appointed Erasmus Smith professor of natural and experimental philosophy.  Eventually, in 1951, Walton was awarded the Nobel Prize for physics along with Cockcroft.  This was a recognition of the highest order, but his wife told a neighbour that for his family the prize meant they could now buy a car.

      Though his friend had followed a more high-profile career, Ernest Walton was content to concentrate his attention on more local developments in his native country.  In 1952 he became chairman of the school of cosmic physics at the Dublin Institute of Advanced Studies (which had been established by EAMON DE VALERA [2] to provide a base for the German scientist Erwin Schroedinger, exiled by the Nazis).  In 1960 he was elected a senior fellow of Trinity College, where the physics laboratory now bears his name.  He died on 25th June 1995, having lived to see both the triumph and, as many would think, the failure of the atomic age.