Editing Mark Oliphant (section)

{{Short description|Australian physicist (1901–2000)}}
{{featured article}}
{{Use dmy dates|date=October 2022}}
{{Use Australian English|date=April 2013}}
{{Infobox scientist
| honorific_prefix  = [[Sir]]
| name              = Mark Oliphant
| honorific_suffix  = {{postnominals|country=AUS|size=100%|AC|KBE|FRS|FAA|FTSE}}
| image             = Sir Mark Oliphant.jpg
| caption           = Oliphant in 1939
| birth_name        = Marcus Laurence Elwin Oliphant
| birth_date        = {{Birth date|1901|10|8|df=y}}
| birth_place       = [[Adelaide]], [[South Australia]], Australia
| death_date        = {{Death date and age|2000|7|14|1901|10|8|df=y}}
| death_place       = [[Canberra]], [[Australian Capital Territory]], Australia
| work_institution  = {{Plainlist|
* [[Cavendish Laboratory]]
* [[Lawrence Berkeley National Laboratory]]
* [[University of Birmingham]]
* [[Australian National University]]}}
| education        = {{Plainlist|
* [[University of Adelaide]]
* [[Trinity College, Cambridge]]}}
| doctoral_advisor  = [[Ernest Rutherford]]
| thesis_title      = The Neutralization of Positive Ions at Metal Surfaces, and the Emission of Secondary Electrons
| thesis_year       = 1929
| academic_advisors = 
| doctoral_students = {{Plainlist|
*[[Ernest William Titterton]]
*[[Alan Howard Ward]] }}
| known_for         = {{Plainlist|
* Co-discovery of [[tritium]], [[helium-3]] and [[nuclear fusion]]
* Development of [[microwave radar]]}}
| prizes            = {{Plainlist|
* [[Fellow of the Royal Society]] (1937)
* [[Hughes Medal]] (1943)
* [[Faraday Medal]] (1948)
* [[James Cook Medal]] (1974)
* [[ANZAAS Medal]] (1979) }}
| footnotes         = 
| module            = {{Infobox officeholder
| embed=yes|
| order               = 27th
| office              = Governor of South Australia
| term_start          = 1 December 1971
| term_end            = 30 November 1976
| lieutenant_governor = {{ubl|[[Mellis Napier|Sir Mellis Napier]] (1971–1973)|[[Walter Crocker|Sir Walter Crocker]] (1973–1976)}}
| monarch             = [[Elizabeth II]]
| premier             = [[Don Dunstan]]
| predecessor         = [[James Harrison (Australian governor)|Sir James Harrison]]
| successor           = [[Douglas Nicholls|Sir Douglas Nicholls]]
| party               = [[Australia Party]] (until 1977)<br/>[[Australian Democrats]] (from 1977)
}}
}}
'''Sir Marcus Laurence Elwin Oliphant''', {{postnominals|country=AUS|size=100%|sep=,|AC|KBE|FRS|FAA|FTSE}} (8 October 1901 – 14 July 2000) was an Australian [[physicist]] and [[humanitarian]] who played an important role in the first experimental demonstration of [[nuclear fusion]] and in the [[History of nuclear weapons|development of nuclear weapon]]s.

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 (element)|mercury]], and went to England, where he studied under Sir [[Ernest Rutherford]] at the [[University of Cambridge]]'s [[Cavendish Laboratory]]. There, he used a [[particle accelerator]] to fire [[heavy hydrogen]] [[atomic nucleus|nuclei]] ([[deuteron]]s) at various targets. He discovered the respective nuclei of [[helium-3]] (helions) and of [[tritium]] (tritons). He also discovered that when they [[neutron–proton ratio|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 [[John Henry Poynting|Poynting]] Professor of Physics at the [[University of Birmingham]]. He attempted to build a {{convert|60|inch|cm|adj=on}} [[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 (physicist)|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 [[Lawrence Berkeley National Laboratory|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]] (ANU), where he initiated the design and construction of the world's largest (500 megajoule) [[homopolar generator]]. He retired in 1967, but was appointed [[Governor of South Australia]] on the advice of [[Premier of South Australia|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 he was the 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.