'... we had no idea whatever that this would one day be applied to make hydrogen bombs. Our curiosity was just curiosity about the structure of the nucleus of the atom, and the discovery of these reactions was purely, as the Americans would put it, coincidental.'
Marcus Laurence Elwin Oliphant (known as Sir Mark Oliphant) is the eldest of five sons and was born in 1901 in Kent Town, near Adelaide, South Australia. His father was a civil servant and his mother was an artist. Oliphant was interested in pursuing a career in medicine or chemistry, and in 1919 began studying at the University of Adelaide. However, his physics teacher, Dr Roy Burdon, showed him that there was more to physics than met the eye, and Oliphant was hooked. In a 1967 taped interview, he later remarked:
'I was lucky in having a very good teacher in physics in Adelaide, a man named Burdon, Dr Roy Burdon, who started me off with enthusiasm on this subject and who weaned me away, I think, from my ideas of being a chemist or a doctor and taught me the extraordinary exhilaration there was in even minor discoveries in the field of physics.' 
In 1925, Oliphant was further inspired after hearing a lecture by Ernest Rutherford, a New Zealand physicist. A giant in the field of nuclear physics, Rutherford had made discoveries about radioactivity and the atomic nucleus.
'The man who has influenced me to the greatest extent in life is Rutherford ... he talked about the work going on in the Cavendish Laboratory. And I absolutely fell in love with this man. I just immediately decided that this was the man I was going to work with, if possible.' 
To finance his university studies, Oliphant initially worked in the South Australian Public Library, but was lured by Professor Kerr Grant to take up a cadetship in the Physics Department. Oliphant graduated with a Bachelor of Science, First Class Honours in Physics, in 1922. He continued to work in the Physics Department, managing to do further research in between his duties as a laboratory assistant.
In 1927 Oliphant had the opportunity to fulfil this dream. He won an '1851 Exhibitioner' scholarship that enabled him to study under the supervision of Rutherford at the famous Cavendish Laboratory at Cambridge University in England. Oliphant said:
'[Rutherford] received me with immense kindness, and from my first moment of meeting him, I felt at home with him, a feeling that lasted throughout my association with him, which was until his death in 1937 ... Rutherford was the most inspiring man I have ever met, unassuming, determined always, an extremely hard worker, and I found myself therefore in very congenial company because I like to work hard as well' 
Oliphant made his most significant personal contributions to science during his time at the Cavendish Laboratory. He started research in the field of nuclear physics, working on the artificial disintegration of the atomic nucleus, and positive ions, gaining his PhD in 1929. Oliphant also designed and built complicated apparatus, including a positive ion accelerator and a cyclotron. This was not an easy task, as the Cavendish Laboratory was not well-funded. Equipment was often built by the researchers out of whatever bits and pieces they could find, resulting in 'the famed "string and ceiling wax" approach ... which included the use of biscuit and coffee tins as essential pieces of apparatus'.
Many exciting discoveries were being made at the Cavendish Laboratory, and the field of nuclear physics was rapidly expanding.
'Arguably, 1932 was the year of greatest achievement at the Cavendish with three discoveries of such importance that they truly deserve the overworked accolade "breakthrough". For the previous two decades, the standard model of the atom had contained two types of particles: the light, negatively charged electrons and lumps of postively charged matter called protons. Then in the space of a few months, the number of known fundamental particles doubled from two to four; the atoms of the lighter elements, far from being indivisible, were broken open at will; and powerful new machinery for both producing and detecting the particles came into use.' 
Sir John Cockcroft and Ernest Walton made the first major breakthrough in 1932 when they split the atom for the first time, using their high-powered particle accelerator, the first ever built. Then, Sir James Chadwick identified the third atomic particle, the neutron. The last major 1932 Cavendish Laboratory breakthrough belonged to Patrick Blackett, who identified electrons with a postive charge. This proved the existence of 'anti-matter'.
Rutherford then asked Oliphant to work with him to further investigate Cockcroft and Walton's work. Together, they repeated these experiments, but with greater precision. Oliphant discovered new forms of Hydrogen (Deuterium and Tritium) and Helium (Helium 3); discoveries which laid the foundation for the development of nuclear weapons. Oliphant said of this work:
'In this work, which we did together, we were able to discover two new kinds of atomic species, one was hydrogen of mass 3 [Tritium], unknown until that time, and the other helium of mass 3, also unknown. These new atoms were produced as a result of atomic transformations induced by our ion beam hitting targets of lithium, beryllium and other materials.
Incidentally, at the same time, we were able to show that heavy hydrogen nuclei, that is to say the cores of heavy hydrogen atoms, could be made to react with one another to produce a good deal of energy and new kinds of atoms. This particular reaction, which we discovered at this time, is the basic reaction in the so-called hydrogen bomb.' 
In 1937 Oliphant accepted an invitation to become Poynting Professor of Physics at the University of Birmingham. Here, he established a nuclear physics research program, and built a large cyclotron to allow further research.
Following the onset of the Second World War, Oliphant's research focus changed to support the war effort. Initially, he was in charge of a team that successfully developed microwave radar. Then, in November 1943, Oliphant moved to the USA to work on the Manhattan Project. While Oppenheimer worked on the Bomb in Los Alamos, Oliphant preferred to focus on the electromagnetic method (in particular, the electromagnetic separation of the different forms of Uranium) with Ernest Lawrence in Berkeley. During the war, Oliphant travelled back and forth between the USA and the UK, leading a team of British physicists who were collaborating with American scientists on the development of the atomic bomb.
Yet , Oliphant publicly opposed the development of atomic weapons as a misuse of atomic power:
'I suddenly realised that anybody who has a nuclear reactor can extract the plutonium from the reactor and make nuclear weapons, so that a country which has a nuclear reactor can, at any moment that it wants to, become a nuclear weapons power. And I, right from the beginning, have been terribly worried by the existence of nuclear weapons and very much against their use.'
Oliphant finished working for the Manhattan Project in April 1945 and returned to England. He did not witness the test-firing of the Bomb, nor was he involved in the often intense and top-secret Bomb-usage debates that followed. After the atomic bomb was dropped on Hiroshima on 6 August 1945, Oliphant could not believe that it had happened; that the Bomb had actually been used. From that time on, he became an advocate for the peacful use of atomic energy, speaking out and encouraging the 'positive co-operation for good, [to] ensure that the scientific achievement of atomic energy is a decisive step towards the better life for all.'
After the war, Oliphant returned to the University of Birmingham, where he continued as Professor of Physics and helped build the proton-synchrotron. In 1950 he was approached by the newly-established Australian National University to become the first Director of the ANU Research School of Physical Sciences. He accepted and returned to Australia with his family.
Establishing the Australian Academy of Science was one of Oliphant's proudest achievements. He realised, upon his return to Australia in 1950, 'that Australia had no voice, no international voice' in the scientific arena. He worked hard to bring the most distinguished scientists from around Australia together to form the Academy. In 1954 their Charter was presented to the Queen on her first visit to Australia, and the Academy was officially established. Oliphant was its first President (1954-56).
After retiring from the ANU in 1967, Oliphant became the State Governor of South Australia in 1971. Among his other duties, Oliphant liked to promote science in South Australian schools and universities. His five-year term ended on 30 November 1976, with a garden party for two thousand guests.
Sir Mark Oliphant retired to Canberra in 1976 and still lives there today. He continues to enthusiastically promote science and technology, and shows great dedication to fostering the growth and development of Australian science.
Conversation with Sir Mark Oliphant, 24 July 1967, National Library Collection, Tape 276, p. 5 of 12 page transcript (Interviewed by Hazel de Berg).
 Conversation with Sir Mark Oliphant, July 1967, National Library Collection, Tape 276, p. 1 of 12 page transcript (Interviewed by Hazel de Berg).
 Moyal, Ann, Portraits in Science, National Library of Australia, 1994, p. 37.
 Conversation with Sir Mark Oliphant, 24 July 1967, National Library Collection, Tape 276, pp. 1 & 4 of 12 page transcript (Interviewed by Hazel de Berg).
 Cockburn, Stewart & Ellyard, David, Oliphant: the life and times of Sir Mark Oliphant, Axiom Books, Adelaide, 1981, p. 37.
 Ellyard, David, 'Hydrogen's evangelist', New Scientist, 14 November 1992, pp. 36-7.
 Conversation with Sir Mark Oliphant, 24 July 1967, National Library Collection, Tape 276, p. 5 of 12 page transcript (Interviewed by Hazel de Berg).
 Moyal, Ann, Portraits in Science, National Library of Australia, 1994, p. 31.
 Cockburn, Stewart & Ellyard, David, Oliphant: the life and times of Sir Mark Oliphant, Axiom Books, Adelaide, 1981, p. 130.
 Moyal, Ann, Portraits in Science, National Library of Australia, 1994, p. 32.