Alan Mathison Turing

Background

Turing was born in Maida Vale, London, to Julius Mathison Turing, an Indian Civil Service officer, and Ethel Sara Turing. His family had connections with British India, Scotland, the Netherlands, Ireland, and the Anglo-Irish professional class. His parents wished their sons to be raised in Britain, and Alan spent parts of his childhood between England and India while his parents travelled for Julius's service.

He was raised partly in southern England, including Hastings and Guildford. He had an elder brother, John Ferrier Turing. Scientific reading, including Edwin Tenney Brewster's Natural Wonders Every Child Should Know, contributed to his early interest in the natural world. At Sherborne School he developed a close intellectual friendship with Christopher Morcom, whose death in 1930 deeply affected him and whom Turing associated with his continuing commitment to scientific work.

Education

Turing attended St Michael's in St Leonards-on-Sea and Hazelhurst Preparatory School before entering Sherborne School in 1926. Sherborne was an independent boarding school whose traditional curriculum placed strong emphasis on classical education, while Turing showed exceptional ability in mathematics and science.

He studied mathematics at King's College, Cambridge, from 1931 to 1934 and received first-class honours. King's was a constituent college of the University of Cambridge, an institution with a long mathematical tradition and a competitive scholarship system. Turing was elected a Fellow of King's College in 1935 and completed Part III of the Mathematical Tripos in 1937.

From 1936 to 1938 he studied at Princeton University under Alonzo Church, first as a Jane Eliza Procter Visiting Fellow and then as a doctoral student. Princeton's Department of Mathematics was a major center for modern mathematical logic. Turing received his PhD in 1938 for a dissertation on ordinal logic and relative computation.

Career

Turing's early mathematical work concerned probability, logic, and the limits of computation. His 1936 paper on computable numbers introduced the abstract Turing machine and established a result on the undecidability of the Entscheidungsproblem. This work helped define computation as a mathematical subject and provided the conceptual basis for the idea of a general-purpose computer.

From 1938 he worked part-time with the Government Code and Cypher School, and in September 1939 joined its wartime headquarters at Bletchley Park. He worked first on German Enigma traffic and became the leading figure in Hut 8's attack on naval Enigma. He specified the electromechanical bombe, developed the statistical method called Banburismus, and devised Turingery for analysis of the Lorenz cipher. He also contributed to secure speech work at Bell Labs in the United States and later helped design the portable Delilah voice-encryption system at Hanslope Park. His wartime work remained secret under the Official Secrets Act, although he was appointed an Officer of the Order of the British Empire in 1946.

After the war, Turing worked at the National Physical Laboratory from 1945 to 1947, where he designed the Automatic Computing Engine, one of the earliest detailed stored-program computer designs. He returned to Cambridge for a year and then joined the University of Manchester in 1948 as a reader in mathematics. At Manchester he became deputy director of the Computing Machine Laboratory, worked on software for the Manchester Mark 1, wrote an early programmer's manual, and consulted for Ferranti during development of the Ferranti Mark 1.

Turing also made major contributions to artificial intelligence and mathematical biology. His 1950 paper on computing machinery and intelligence proposed what became known as the Turing test. In 1952 he published a mathematical account of morphogenesis based on reaction-diffusion systems, explaining how chemical interactions could generate biological patterns. His work was interrupted by his 1952 conviction for gross indecency; he received probation conditional on chemical treatment, and his security clearance and cryptographic consultancy were withdrawn. Turing died in Wilmslow in 1954.

Achievements

• Turing introduced the Turing machine and proved a fundamental limit on algorithmic decision procedures in his work on computable numbers and the Entscheidungsproblem.

• He specified the electromechanical bombe and developed major mathematical procedures used in the wartime analysis of German Enigma and Lorenz communications.

• He designed the Automatic Computing Engine, an early detailed stored-program computer proposal, while working at the National Physical Laboratory.

• He proposed the Turing test as a practical way to discuss machine intelligence and the possibility of distinguishing machine conversation from human conversation.

• His reaction-diffusion theory of morphogenesis provided a mathematical framework for explaining the emergence of biological patterns from chemical processes.

Works

• article

  • On Computable Numbers, with an Application to the Entscheidungsproblem

    (Foundational paper introducing the abstract Turing machin...)

    1936

  • The Chemical Basis of Morphogenesis

    (Mathematical biology paper proposing reaction-diffusion m...)

    1952

  • Systems of Logic Based on Ordinals

    (A study of ordinal logic and relative computation based o...)

    1939

  • Computing Machinery and Intelligence

    (Paper in Mind that introduced the imitation game, later w...)

    1950

  • Equivalence of Left and Right Almost Periodicity

    (Turing's first published mathematical paper, concerning a...)

    1935

• computer program

  • Turochamp

    (A chess-playing program developed with D. G. Champernowne...)

    1950

• essay

  • The Nature of Spirit

    (An unpublished philosophical writing in which Turing cons...)

    1932

• paper

  • The Applications of Probability to Cryptography

    (A wartime mathematical paper on probability and cryptanal...)

  • Intelligent Machinery

    (A seminal unpublished-in-his-lifetime work addressing mac...)

    1948

  • Paper on Statistics of Repetitions

    (A wartime study applying statistical reasoning to cryptan...)

• short story

  • Pryce's Buoy

    (An unfinished short story written in the early 1950s and ...)

    1953

Views

Turing's work explored the relationship between formal rules, mathematical reasoning, and mechanical computation. His theory of computation treated procedures as operations that could be represented by an abstract machine, while his later writing on artificial intelligence questioned how intelligence should be recognized in a machine.

His writings also addressed mind, matter, and spirit. In The Nature of Spirit and letters to Frances Morcom, he considered whether spirit could exist independently of the body, although his views do not establish a formal religious affiliation. His mathematical biology proposed that complex organic patterns could arise from physical and chemical processes.

Membership

Turing was a member of the Ratio Club, a London discussion group for researchers interested in cybernetics, computing, neuroscience, and biology. He also belonged to the Manchester Literary and Philosophical Society. These organizations connected his mathematical and computing work with wider scientific and intellectual discussions.

• Participated in meetings and presented talks on computing machinery, intelligence, and morphogenesis.

  Ratio Club , United Kingdom

  1950

• Elected to membership while working at the University of Manchester.

  Manchester Literary and Philosophical Society , United Kingdom

  1948

Personality

Colleagues and biographers described Turing as intellectually original, unconventional, and sometimes eccentric. His documented habits included long-distance running, unusual practical solutions to everyday problems, and a playful interest in chess, machines, and his teddy bear Porgy.

Quotes from others about the person

• Bletchley Park colleague Jack Good described Turing as a genius whose work was central to Hut 8's success. Peter Hilton later characterized the experience of working with Turing as an encounter with an intelligence of exceptional depth and originality.

Interests

• Chess, astronomy, scientific reading, and mathematical games.

• Sport & Clubs

  Long-distance running and marathon running.

Connections

Turing's parents were Julius Mathison Turing and Ethel Sara Turing. His elder brother was John Ferrier Turing, whose son was Dermot Turing. Turing was engaged briefly to Joan Clarke, a mathematician and cryptanalyst who worked with him at Bletchley Park; the engagement ended after he disclosed his homosexuality.

Christopher Morcom was Turing's school friend and an important intellectual companion at Sherborne. Morcom died in 1930, and Turing maintained a correspondence with Morcom's mother, Frances Isobel Morcom. Turing later had a relationship with Arnold Murray, which came to light during a police investigation and led to his prosecution in 1952.

Father:

Julius Mathison Turing

Indian Civil Service officer in British India.

Mother:

Ethel Sara Turing

Daughter of Edward Waller Stoney, chief engineer of the Madras Railways.

Brother:

John Ferrier Turing

Alan Turing's elder brother.

Collegue :

Christopher Morcom

School friend and intellectual companion at Sherborne School.

fiancee:

Joan Clarke

Mathematician and cryptanalyst who worked with Turing at Bletchley Park.

Partner:

Arnold Murray

Turing's partner in a relationship that led to his 1952 prosecution.

nephew:

Dermot Turing

Son of Turing's elder brother, John Ferrier Turing.

References

• Lovesong of the Electric Bear Play by Snoo Wilson that includes Turing and his teddy bear Porgy as subjects.
  2015
• Turing and the Universal Machine Book by Jon Agar examining Turing's contribution to the history of computing.
  2001
• The government machine: a revolutionary history of the computer History by Jon Agar discussing the development of computing, including Turing's work.
  2003
• The Works of Charles Babbage: Passages from the Life of a Philosopher Edition of Charles Babbage's work relevant to the history of programmable computation.
  2016
• The control revolution: technological and economic origins of the information society Study by James Beniger placing computing in the history of information systems.
  1986
• Turing's Vision: The Birth of Computer Science Book by Chris Bernhardt on Turing's mathematical foundations of computer science.
  2017
• Electric Universe: How Electricity Switched on the Modern World History by David Bodanis discussing the technological setting of modern electrical and computing systems.
  2005
• Konrad Zuse und die Schweiz. Wer hat den Computer erfunden? Study by Herbert Bruderer concerning early computer development and Turing's connection with the history of computing.
  2012
• Computer: A History of the Information Machine History by Martin Campbell-Kelly covering the emergence of the computer and Turing's contribution.
  1996
• A History of Modern Computing Historical account by Paul E. Ceruzzi of modern computing, including early stored-program machines.
  1998
• The Visible Hand: The Managerial Revolution in American Business Economic history by Alfred Chandler providing context for the organizational development of modern technology.
  1977
• Alan Turing: His Work and Impact Collection examining Turing's contributions to mathematics, computing, cryptanalysis, and biology.
  2013
• Alan Turing's Automatic Computing Engine Book on Turing's design for the Automatic Computing Engine at the National Physical Laboratory.
  2005
• The Turing Guide Reference work discussing Turing's life, mathematical work, codebreaking, computing, and legacy.
  2017
• Turing's Cathedral: The Origins of the Digital Universe History by George Dyson on the origins of digital computing and the intellectual environment surrounding Turing's work.
  2012
• The closed world: computers and the politics of discourse in Cold War America Study by Paul N. Edwards on computers, politics, and Cold War intellectual history.
  1996
• The Information: A History, a Theory, a Flood History by James Gleick discussing information theory, computation, and Turing's place in the history of information.
  2011
• Alan Turing: en berättelse Biographical work by Rolf Hochhuth about Turing.
  1988
• A Madman Dreams of Turing Machines Book by Janna Levin exploring the intellectual history of Turing machines and related mathematical ideas.
  2006
• Infoculture History by Steven Lubar examining information culture and the development of computing.
  1993