Mark Oliphant
Sir Marcus Laurence Elwin Oliphant was an Australian physicist and humanitarian who played an important role in the first experimental demonstration of nuclear fusion and in the development of nuclear weapons.
Born and raised in Adelaide, South Australia, Oliphant graduated from the University of Adelaide in 1922. He was awarded an 1851 Exhibition Scholarship in 1927 on the strength of the research he had done on mercury, and went to England where he studied under Sir Ernest Rutherford at the University of Cambridge's Cavendish Laboratory. There, he discovered the respective nuclei of helium-3 and of tritium. He also discovered that when they reacted with each other, the particles that were released had far more energy than they started with. Energy had been liberated from inside the nucleus, and he realised that this was a result of nuclear fusion.
Oliphant left the Cavendish Laboratory in 1937 to become the Poynting Professor of Physics at the University of Birmingham. He attempted to build a cyclotron at the university, but its completion was postponed by the outbreak of the Second World War in Europe in 1939. He became involved with the development of radar, heading a group at the University of Birmingham that included John Randall and Harry Boot. They created a radical new design, the cavity magnetron, that made microwave radar possible. Oliphant also formed part of the MAUD Committee, which reported in July 1941, that an atomic bomb was not only feasible, but might be produced as early as 1943. Oliphant was instrumental in spreading the word of this finding in the United States, thereby starting what became the Manhattan Project. Later in the war, he worked on it with his friend Ernest Lawrence at the Radiation Laboratory in Berkeley, California, developing electromagnetic isotope separation, which provided the fissile component of the Little Boy atomic bomb used in the atomic bombing of Hiroshima in August 1945.
After the war, Oliphant returned to Australia as the first director of the Research School of Physical Sciences and Engineering at the new Australian National University, where he initiated the design and construction of the world's largest homopolar generator. He retired in 1967, but was appointed Governor of South Australia on the advice of the premier, Don Dunstan. He became the first South Australian-born governor of South Australia. He assisted in the founding of the Australian Democrats political party and was chairman of the meeting in Melbourne in 1977 at which the party was launched. Late in life he witnessed his wife, Rosa, suffer before her death in 1987, and he became an advocate for voluntary euthanasia. He died in Canberra in 2000.
Early life
Marcus Laurence Elwin Oliphant was born on 8 October 1901 in Kent Town, a suburb of Adelaide. His father was Harold George "Baron" Olifent, a civil servant with the South Australian Engineering and Water Supply Department and part-time lecturer in economics with the Workers' Educational Association. His mother was Beatrice Edith Fanny Oliphant, née Tucker, an artist. He was named after Marcus Clarke, the Australian author, and Laurence Oliphant, the British traveller and mystic. Most people called him "Mark"; this became official when he was knighted in 1959.He had four younger brothers: Roland, Keith, Nigel and Donald; all were registered at birth with the surname Olifent. His grandfather, Harry Smith Olifent, was a clerk at the Adelaide GPO. His great-grandfather James Smith Olifent and his wife Eliza left their native Kent for South Australia aboard the barque Ruby, arriving in March 1854. He would later be appointed superintendent of the Adelaide Destitute Asylum, and Eliza Olifent was appointed matron of the establishment in 1865. Oliphant's parents were Theosophists, and as such may have refrained from eating meat. He became a lifelong vegetarian while a boy, after witnessing the slaughter of pigs on a farm. He was found to be completely deaf in one ear and he needed glasses for severe astigmatism and short-sightedness.
Oliphant was first educated at primary schools in Goodwood and Mylor, after the family moved there in 1910. He attended Unley High School in Adelaide, and, for his final year in 1918, Adelaide High School. After graduation he failed to obtain a bursary to attend university, so he took a job with S. Schlank & Co., an Adelaide manufacturing jeweller noted for medallions. He then secured a cadetship with the State Library of South Australia, which allowed him to take courses at the University of Adelaide at night.
In 1919, Oliphant began studying at the University of Adelaide. At first he was interested in a career in medicine, but later in the year, Kerr Grant, the physics professor, offered him a cadetship in the physics department. It paid 10 shillings a week, the same amount that Oliphant received for working at the State Library, but it allowed him to take any university course that did not conflict with his work for the department. He received his Bachelor of Science degree in 1921 and then did honours in 1922, supervised by Grant. Roy Burdon, who acted as head of the department when Grant went on sabbatical in 1925, worked with Oliphant to produce two papers in 1927 on the properties of mercury, "The Problem of the Surface Tension of Mercury and the Action of Aqueous Solutions on a Mercury Surface" and "Adsorption of Gases on the Surface of Mercury". Oliphant later recalled that Burdon taught him "the extraordinary exhilaration there was in even minor discoveries in the field of physics".
Oliphant married Rosa Louise Wilbraham, who was from Adelaide, on 23 May 1925. The two had known each other since they were teenagers. He made Rosa's wedding ring in the laboratory from a gold nugget from the Coolgardie goldfields that his father had given him.
Cavendish Laboratory
In 1925, Oliphant heard a speech given by the New Zealand physicist Sir Ernest Rutherford, and he decided he wanted to work for him – an ambition that he fulfilled by earning a position at the Cavendish Laboratory at the University of Cambridge in 1927. He applied for an 1851 Exhibition Scholarship on the strength of the research he had done on mercury with Burdon. It came with a living allowance of £250 per annum. When word came through that he had been awarded a fellowship, he wired Rutherford and Trinity College, Cambridge. Both accepted him.File:The Cavendish Laboratory - geograph.org.uk - 631839.jpg|thumb|The Cavendish Laboratory was the home of some of the great discoveries in physics. It was founded in 1874 by the Duke of Devonshire, and its first professor was James Clerk Maxwell.
Rutherford's Cavendish Laboratory was carrying out some of the most advanced research into nuclear physics in the world at the time. Oliphant was invited to afternoon tea by Rutherford and Lady Rutherford. He soon met other researchers at the Cavendish Laboratory, including Patrick Blackett, Edward Bullard, James Chadwick, John Cockcroft, Charles Ellis, Peter Kapitza, Egon Bretscher, Philip Moon and Ernest Walton. There were two fellow Australians: Harrie Massey and John Keith Roberts. Oliphant would become especially close friends with Cockcroft. The laboratory had considerable talent but little money to spare, and tended to use a "string and sealing wax" approach to experimental equipment. Oliphant had to buy his own equipment, at one point spending £24 of his allowance on a vacuum pump.
Oliphant submitted his PhD thesis on "The Neutralization of Positive Ions at Metal Surfaces, and the Emission of Secondary Electrons" in December 1929. For his viva, he was examined by Rutherford and Ellis. Receiving his degree was the attainment of a major life goal, but it also meant the end of his 1851 Exhibition Scholarship. Oliphant secured an 1851 Senior Studentship, of which there were five awarded each year. It came with a living allowance of £450 per annum for two years, with the possibility of a one-year extension in exceptional circumstances, which Oliphant was also awarded.
A son, Geoffrey Bruce Oliphant, was born 6 October 1930, but he died of meningitis on 5 September 1933. He was interred in an unmarked grave in the Ascension Parish Burial Ground in Cambridge, alongside Timothy Cockcroft, the infant son of Sir John and Lady Elizabeth Cockcroft, who had died the year before. Unable to have more children, the Oliphants adopted a four-month-old boy, Michael John, in 1936, and a daughter, Vivian, in 1938.
In 1932 and 1933, the scientists at the Cavendish Laboratory made a series of ground-breaking discoveries. Cockcroft and Walton bombarded lithium with high energy protons and succeeded in transmuting it into energetic nuclei of helium. This was one of the earliest experiments to change the atomic nucleus of one element to another by artificial means. Chadwick then devised an experiment that discovered a new, uncharged particle with roughly the same mass as the proton: the neutron. In 1933, Blackett discovered tracks in his cloud chamber that confirmed the existence of the positron and revealed the opposing spiral traces of positron–electron pair production.
Oliphant followed up the work by constructing a particle accelerator that could fire protons with up to 600,000 electronvolts of energy. He soon confirmed the results of Cockcroft and Walton on the artificial disintegration of the nucleus and positive ions. He produced a series of six papers over the following two years. In 1933, the Cavendish Laboratory received a gift from the American physical chemist Gilbert N. Lewis of a few drops of heavy water. The accelerator was used to fire heavy hydrogen nuclei at various targets. Working with Rutherford and others, Oliphant thereby discovered the nuclei of helium-3 and tritium.
Oliphant used electromagnetic separation to separate the isotopes of lithium. He was the first to experimentally demonstrate nuclear fusion. He found that when deuterons reacted with nuclei of helium-3, tritium or with other deuterons, the particles that were released had far more energy than they started with. Binding energy had been liberated from inside the nucleus. Following Arthur Eddington's 1920 prediction that energy released by fusing small nuclei together could provide the energy source that powers the stars, Oliphant speculated that nuclear fusion reactions might be what powered the sun. With its higher cross section, the deuterium–tritium nuclear fusion reaction became the basis of a hydrogen bomb. Oliphant had not foreseen this development:
In 1934, Cockcroft arranged for Oliphant to become a fellow of St John's College, Cambridge, which paid about £600 a year. When Chadwick left the Cavendish Laboratory for the University of Liverpool in 1935, Oliphant and Ellis both replaced him as Rutherford's assistant director for research. The job came with a salary of £600. With the money from St John's, this gave him a comfortable income. Oliphant soon fitted out a new accelerator laboratory with a 1.23 MeV generator at a cost of £6,000 while he designed an even larger 2 MeV generator. In 1937, he was elected to the Royal Society. When he died he was its longest-serving fellow.