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Childhood's End: Was Arthur C. Clarke A Pedophile?

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Childhood's End: Was Arthur C. Clarke A Pedophile?

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Ep 798 - Childhood’s End: Was Arthur C. Clarke A Pedophile?

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Listen to Ep 798 - Childhood’s End: Was Arthur C. Clarke A Pedophile? - Dead Rabbit Radio podcast for free on GetPodcast.

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Alan Mathison Turing (; 23 June 1912 - 7 June 1954) was an English mathematician, computer scientist, logician, cryptanalyst, philosopher and theoretical biologist. Turing was highly influential in the development of theoretical computer science, providing a formalisation of the concepts of algorithm and computation with the Turing machine, which can be considered a model of a general-purpose computer. He is widely considered to be the father of theoretical computer science and artificial intelligence.

Born in London, Turing was raised in southern England. He graduated in maths from King's College, Cambridge, and in 1938, earned a maths PhD from Princeton University. During the Second World War, Turing worked for the Government Code and Cypher School at Bletchley Park, Britain's codebreaking centre that produced Ultra intelligence. He led Hut 8, the section responsible for German naval cryptanalysis. He devised techniques for speeding the breaking of German ciphers, including improvements to the pre-war Polish bomba method, an electromechanical machine that could find settings for the Enigma machine. Turing played a crucial role in cracking intercepted messages that enabled the Allies to defeat the Axis powers in many crucial engagements, including the Battle of the Atlantic.

After the war, Turing worked at the National Physical Laboratory, where he designed the Automatic Computing Engine, one of the first designs for a stored-program computer. In 1948, Turing joined Max Newman's Computing Machine Laboratory at the Victoria University of Manchester, where he helped develop the Manchester computers and became interested in mathematical biology. He wrote on the chemical basis of morphogenesis and predicted oscillating chemical reactions such as the Belousov-Zhabotinsky reaction, first observed in the 1960s. Despite these accomplishments, Turing was never fully recognised during his lifetime because much of his work was covered by the Official Secrets Act.

Turing was prosecuted in 1952 for homosexual acts. He accepted hormone treatment, a procedure commonly referred to as chemical castration, as an alternative to prison. Turing died on 7 June 1954, aged 41, from cyanide poisoning. An inquest determined his death as suicide, but the evidence is also consistent with accidental poisoning. Following a campaign in 2009, British prime minister Gordon Brown made an official public apology for "the appalling way [Turing] was treated". Queen Elizabeth II granted a pardon in 2013. The term " Alan Turing law" is used informally to refer to a 2017 law in the UK that retroactively pardoned men cautioned or convicted under historical legislation that outlawed homosexual acts.

Turing has an extensive legacy with statues and many things named after him, including an annual award for computer science innovations. He appears on the current Bank of England £50 note, which was released on 23 June 2021 to coincide with his birthday. A 2019 BBC series, as voted by the audience, named him the greatest person of the 20th century.

Early life and education

English Heritage plaque in Maida Vale, London marking Turing's birthplace in 1912

Turing was born in Maida Vale, London, while his father, Julius Mathison Turing was on leave from his position with the Indian Civil Service (ICS) of the British Raj government at Chatrapur, then in the Madras Presidency and presently in Odisha state, in India. Turing's father was the son of a clergyman, the Rev. John Robert Turing, from a Scottish family of merchants that had been based in the Netherlands and included a baronet. Turing's mother, Julius's wife, was Ethel Sara Turing ( née Stoney), daughter of Edward Waller Stoney, chief engineer of the Madras Railways. The Stoneys were a Protestant Anglo-Irish gentry family from both County Tipperary and County Longford, while Ethel herself had spent much of her childhood in County Clare. Julius and Ethel married on 1 October 1907 at Bartholomew's church on Clyde Road, in Dublin.

Julius's work with the ICS brought the family to British India, where his grandfather had been a general in the Bengal Army. However, both Julius and Ethel wanted their children to be brought up in Britain, so they moved to Maida Vale, London, where Alan Turing was born on 23 June 1912, as recorded by a blue plaque on the outside of the house of his birth, later the Colonnade Hotel. Turing had an elder brother, John Ferrier Turing, father of Sir John Dermot Turing, 12th Baronet of the Turing baronets.

Turing's father's civil service commission was still active during Turing's childhood years, and his parents travelled between Hastings in the United Kingdom and India, leaving their two sons to stay with a retired Army couple. At Hastings, Turing stayed at Baston Lodge, Upper Maze Hill, St Leonards-on-Sea, now marked with a blue plaque. The plaque was unveiled on 23 June 2012, the centenary of Turing's birth.

Very early in life, Turing showed signs of the genius that he was later to display prominently. His parents purchased a house in Guildford in 1927, and Turing lived there during school holidays. The location is also marked with a blue plaque.

Turing's parents enrolled him at St Michael's, a primary school at 20 Charles Road, St Leonards-on-Sea, from the age of six to nine. The headmistress recognised his talent, noting that she has "...had clever boys and hardworking boys, but Alan is a genius".

Between January 1922 and 1926, Turing was educated at Hazelhurst Preparatory School, an independent school in the village of Frant in Sussex (now East Sussex). In 1926, at the age of 13, he went on to Sherborne School, an independent boarding school in the market town of Sherborne in Dorset, where he boarded at Westcott House. The first day of term coincided with the 1926 General Strike, in Britain, but Turing was so determined to attend that he rode his bicycle unaccompanied 60 miles (97 km) from Southampton to Sherborne, stopping overnight at an inn.

Turing's natural inclination towards mathematics and science did not earn him respect from some of the teachers at Sherborne, whose definition of education placed more emphasis on the classics. His headmaster wrote to his parents: "I hope he will not fall between two stools. If he is to stay at public school, he must aim at becoming educated. If he is to be solely a Scientific Specialist, he is wasting his time at a public school". Despite this, Turing continued to show remarkable ability in the studies he loved, solving advanced problems in 1927 without having studied even elementary calculus. In 1928, aged 16, Turing encountered Albert Einstein's work; not only did he grasp it, but it is possible that he managed to deduce Einstein's questioning of Newton's laws of motion from a text in which this was never made explicit.

Christopher Morcom

At Sherborne, Turing formed a significant friendship with fellow pupil Christopher Collan Morcom (13 July 1911 - 13 February 1930), who has been described as Turing's first love. Their relationship provided inspiration in Turing's future endeavours, but it was cut short by Morcom's death, in February 1930, from complications of bovine tuberculosis, contracted after drinking infected cow's milk some years previously.

The event caused Turing great sorrow. He coped with his grief by working that much harder on the topics of science and mathematics that he had shared with Morcom. In a letter to Morcom's mother, Frances Isobel Morcom (née Swan), Turing wrote:

Turing's relationship with Morcom's mother continued long after Morcom's death, with her sending gifts to Turing, and him sending letters, typically on Morcom's birthday. A day before the third anniversary of Morcom's death (13 February 1933), he wrote to Mrs. Morcom:

Some have speculated that Morcom's death was the cause of Turing's atheism and materialism. Apparently, at this point in his life he still believed in such concepts as a spirit, independent of the body and surviving death. In a later letter, also written to Morcom's mother, Turing wrote:

Personally, I believe that spirit is really eternally connected with matter but certainly not by the same kind of body ... as regards the actual connection between spirit and body I consider that the body can hold on to a 'spirit', whilst the body is alive and awake the two are firmly connected. When the body is asleep I cannot guess what happens but when the body dies, the 'mechanism' of the body, holding the spirit is gone and the spirit finds a new body sooner or later, perhaps immediately.

University and work on computability

After graduating from Sherborne, Turing applied for several Cambridge colleges scholarships, including Trinity and King's, eventually earning an £80 per annum scholarship (equivalent to about £4,300 as of 2023) to study at the latter. There, Turing studied the undergraduate course in Schedule B (that is, a three-year Parts I and II, of the Mathematical Tripos, with extra courses at the end of the third year, as Part III only emerged as a separate degree in 1934) from February 1931 to November 1934 at King's College, Cambridge, where he was awarded first-class honours in mathematics. His dissertation, On the Gaussian error function, written during his senior year and delivered in November 1934 (with a deadline date of 6 December) proved a version of the central limit theorem. It was finally accepted on 16 March 1935. By spring of that same year, Turing started his master's course (Part III)-which he completed in 1937-and, at the same time, he published his first paper, a one-page article called Equivalence of left and right almost periodicity (sent on 23 April), featured in the tenth volume of the Journal of the London Mathematical Society. Later that year, Turing was elected a Fellow of King's College on the strength of his dissertation. However, and, unknown to Turing, this version of the theorem he proved in his paper, had already been proven, in 1922, by Jarl Waldemar Lindeberg. Despite this, the committee found Turing's methods original and so regarded the work worthy of consideration for the fellowship. Abram Besicovitch's report for the committee went so far as to say that if Turing's work had been published before Lindeberg's, it would have been "an important event in the mathematical literature of that year".

Between the springs of 1935 and 1936, at the same time as Church, Turing worked on the decidability of problems, starting from Gödel's incompleteness theorems. In mid-April 1936, Turing sent Max Newman the first draft typescript of his investigations. That same month, Alonzo Church published his An Unsolvable Problem of Elementary Number Theory, with similar conclusions to Turing's then-yet unpublished work. Finally, on 28 May of that year, he finished and delivered his 36-page paper for publication called " On Computable Numbers, with an Application to the Entscheidungsproblem". It was published in the Proceedings of the London Mathematical Society journal in two parts, the first on 30 November and the second on 23 December. In this paper, Turing reformulated Kurt Gödel's 1931 results on the limits of proof and computation, replacing Gödel's universal arithmetic-based formal language with the formal and simple hypothetical devices that became known as Turing machines. The Entscheidungsproblem (decision problem) was originally posed by German mathematician David Hilbert in 1928. Turing proved that his "universal computing machine" would be capable of performing any conceivable mathematical computation if it were representable as an algorithm. He went on to prove that there was no solution to the decision problem by first showing that the halting problem for Turing machines is undecidable: it is not possible to decide algorithmically whether a Turing machine will ever halt. This paper has been called "easily the most influential math paper in history".

King's College, Cambridge, where Turing was an undergraduate in 1931 and became a Fellow in 1935. The computer room is named after him.

Although Turing's proof was published shortly after Alonzo Church's equivalent proof using his lambda calculus, Turing's approach is considerably more accessible and intuitive than Church's. It also included a notion of a 'Universal Machine' (now known as a universal Turing machine), with the idea that such a machine could perform the tasks of any other computation machine (as indeed could Church's lambda calculus). According to the Church-Turing thesis, Turing machines and the lambda calculus are capable of computing anything that is computable. John von Neumann acknowledged that the central concept of the modern computer was due to Turing's paper. To this day, Turing machines are a central object of study in theory of computation.

From September 1936 to July 1938, Turing spent most of his time studying under Church at Princeton University, in the second year as a Jane Eliza Procter Visiting Fellow. In addition to his purely mathematical work, he studied cryptology and also built three of four stages of an electro-mechanical binary multiplier. In June 1938, he obtained his PhD from the Department of Mathematics at Princeton; his dissertation, Systems of Logic Based on Ordinals, introduced the concept of ordinal logic and the notion of relative computing, in which Turing machines are augmented with so-called oracles, allowing the study of problems that cannot be solved by Turing machines. John von Neumann wanted to hire him as his postdoctoral assistant, but he went back to the United Kingdom.

Career and research

When Turing returned to Cambridge, he attended lectures given in 1939 by Ludwig Wittgenstein about the foundations of mathematics. The lectures have been reconstructed verbatim, including interjections from Turing and other students, from students' notes. Turing and Wittgenstein argued and disagreed, with Turing defending formalism and Wittgenstein propounding his view that mathematics does not discover any absolute truths, but rather invents them.

Cryptanalysis

During the Second World War, Turing was a leading participant in the breaking of German ciphers at Bletchley Park. The historian and wartime codebreaker Asa Briggs has said, "You needed exceptional talent, you needed genius at Bletchley and Turing's was that genius."

From September 1938, Turing worked part-time with the Government Code and Cypher School (GC&CS), the British codebreaking organisation. He concentrated on cryptanalysis of the Enigma cipher machine used by Nazi Germany, together with Dilly Knox, a senior GC&CS codebreaker. Soon after the July 1939 meeting near Warsaw at which the Polish Cipher Bureau gave the British and French details of the wiring of Enigma machine's rotors and their method of decrypting Enigma machine's messages, Turing and Knox developed a broader solution. The Polish method relied on an insecure indicator procedure that the Germans were likely to change, which they in fact did in May 1940. Turing's approach was more general, using crib-based decryption for which he produced the functional specification of the bombe (an improvement on the Polish Bomba).

Two cottages in the stable yard at Bletchley Park. Turing worked here in 1939 and 1940, before moving to Hut 8.

On 4 September 1939, the day after the UK declared war on Germany, Turing reported to Bletchley Park, the wartime station of GC&CS. Like all others who came to Bletchley, he was required to sign the Official Secrets Act, in which he agreed not to disclose anything about his work at Bletchley, with severe legal penalties for violating the Act.

Specifying the bombe was the first of five major cryptanalytical advances that Turing made during the war. The others were: deducing the indicator procedure used by the German navy; developing a statistical procedure dubbed Banburismus for making much more efficient use of the bombes; developing a procedure dubbed for working out the cam settings of the wheels of the Lorenz SZ 40/42 ( Tunny) cipher machine and, towards the end of the war, the development of a portable secure voice scrambler at Hanslope Park that was codenamed Delilah.

By using statistical techniques to optimise the trial of different possibilities in the code breaking process, Turing made an innovative contribution to the subject. He wrote two papers discussing mathematical approaches, titled The Applications of Probability to Cryptography and Paper on Statistics of Repetitions, which were of such value to GC&CS and its successor GCHQ that they were not released to the UK National Archives until April 2012, shortly before the centenary of his birth. A GCHQ mathematician, "who identified himself only as Richard," said at the time that the fact that the contents had been restricted under the Official Secrets Act for some 70 years demonstrated their importance, and their relevance to post-war cryptanalysis:

[He] said the fact that the contents had been restricted "shows what a tremendous importance it has in the foundations of our subject". ... The papers detailed using "mathematical analysis to try and determine which are the more likely settings so that they can be tried as quickly as possible". ... Richard said that GCHQ had now "squeezed the juice" out of the two papers and was "happy for them to be released into the public domain".

Turing had a reputation for eccentricity at Bletchley Park. He was known to his colleagues as "Prof" and his treatise on Enigma was known as the "Prof's Book". According to historian Ronald Lewin, Jack Good, a cryptanalyst who worked with Turing, said of his colleague:

Peter Hilton recounted his experience working with Turing in Hut 8 in his "Reminiscences of Bletchley Park" from A Century of Mathematics in America:

It is a rare experience to meet an authentic genius. Those of us privileged to inhabit the world of scholarship are familiar with the intellectual stimulation furnished by talented colleagues. We can admire the ideas they share with us and are usually able to understand their source; we may even often believe that we ourselves could have created such concepts and originated such thoughts. However, the experience of sharing the intellectual life of a genius is entirely different; one realizes that one is in the presence of an intelligence, a sensibility of such profundity and originality that one is filled with wonder and excitement. Alan Turing was such a genius, and those, like myself, who had the astonishing and unexpected opportunity, created by the strange exigencies of the Second World War, to be able to count Turing as colleague and friend will never forget that experience, nor can we ever lose its immense benefit to us.

Hilton echoed similar thoughts in the Nova PBS documentary Decoding Nazi Secrets.

While working at Bletchley, Turing, who was a talented long-distance runner, occasionally ran the 40 miles (64 km) to London when he was needed for meetings, and he was capable of world-class marathon standards. Turing tried out for the 1948 British Olympic team, but he was hampered by an injury. His tryout time for the marathon was only 11 minutes slower than British silver medallist Thomas Richards' Olympic race time of 2 hours 35 minutes. He was Walton Athletic Club's best runner, a fact discovered when he passed the group while running alone. When asked why he ran so hard in training he replied:

Due to the problems of counterfactual history, it is hard to estimate the precise effect Ultra intelligence had on the war. However, official war historian Harry Hinsley estimated that this work shortened the war in Europe by more than two years and saved over 14 million lives.

At the end of the war, a memo was sent to all those who had worked at Bletchley Park, reminding them that the code of silence dictated by the Official Secrets Act did not end with the war but would continue indefinitely. Thus, even though Turing was appointed an Officer of the Order of the British Empire (OBE) in 1946 by King George VI for his wartime services, his work remained secret for many years.

Within weeks of arriving at Bletchley Park, Turing had specified an electromechanical machine called the bombe, which could break Enigma more effectively than the Polish bomba kryptologiczna, from which its name was derived. The bombe, with an enhancement suggested by mathematician Gordon Welchman, became one of the primary tools, and the major automated one, used to attack Enigma-enciphered messages.

A working replica of a bombe now at The National Museum of Computing on Bletchley Park

The bombe searched for possible correct settings used for an Enigma message (i.e., rotor order, rotor settings and plugboard settings) using a suitable : a fragment of probable plaintext. For each possible setting of the rotors (which had on the order of 10 ¹⁹ states, or 10 ²² states for the four-rotor U-boat variant), the bombe performed a chain of logical deductions based on the crib, implemented electromechanically.

The bombe detected when a contradiction had occurred and ruled out that setting, moving on to the next. Most of the possible settings would cause contradictions and be discarded, leaving only a few to be investigated in detail. A contradiction would occur when an enciphered letter would be turned back into the same plaintext letter, which was impossible with the Enigma. The first bombe was installed on 18 March 1940.

Action This Day

By late 1941, Turing and his fellow cryptanalysts Gordon Welchman, Hugh Alexander and Stuart Milner-Barry were frustrated. Building on the work of the Poles, they had set up a good working system for decrypting Enigma signals, but their limited staff and bombes meant they could not translate all the signals. In the summer, they had considerable success, and shipping losses had fallen to under 100,000 tons a month; however, they badly needed more resources to keep abreast of German adjustments. They had tried to get more people and fund more bombes through the proper channels, but had failed.

On 28 October they wrote directly to Winston Churchill explaining their difficulties, with Turing as the first named. They emphasised how small their need was compared with the vast expenditure of men and money by the forces and compared with the level of assistance they could offer to the forces. As Andrew Hodges, biographer of Turing, later wrote, "This letter had an electric effect." Churchill wrote a memo to General Ismay, which read: "ACTION THIS DAY. Make sure they have all they want on extreme priority and report to me that this has been done." On 18 November, the chief of the secret service reported that every possible measure was being taken. The cryptographers at Bletchley Park did not know of the Prime Minister's response, but as Milner-Barry recalled, "All that we did notice was that almost from that day the rough ways began miraculously to be made smooth." More than two hundred bombes were in operation by the end of the war.

Statue of Turing holding an Enigma machine by Stephen Kettle at Bletchley Park, commissioned by Sidney Frank, built from half a million pieces of Welsh slate[107]

Hut 8 and the naval Enigma

Turing decided to tackle the particularly difficult problem of cracking the German naval use of Enigma "because no one else was doing anything about it and I could have it to myself". In December 1939, Turing solved the essential part of the naval indicator system, which was more complex than the indicator systems used by the other services.

That same night, he also conceived of the idea of Banburismus, a sequential statistical technique (what Abraham Wald later called sequential analysis) to assist in breaking the naval Enigma, "though I was not sure that it would work in practice, and was not, in fact, sure until some days had actually broken". For this, he invented a measure of weight of evidence that he called the . Banburismus could rule out certain sequences of the Enigma rotors, substantially reducing the time needed to test settings on the bombes. Later this sequential process of accumulating sufficient weight of evidence using decibans (one tenth of a ban) was used in cryptanalysis of the Lorenz cipher.

Turing travelled to the United States in November 1942 and worked with US Navy cryptanalysts on the naval Enigma and bombe construction in Washington. He also visited their Computing Machine Laboratory in Dayton, Ohio.

Turing's reaction to the American bombe design was far from enthusiastic:

During this trip, he also assisted at Bell Labs with the development of secure speech devices. He returned to Bletchley Park in March 1943. During his absence, Hugh Alexander had officially assumed the position of head of Hut 8, although Alexander had been de facto head for some time (Turing having little interest in the day-to-day running of the section). Turing became a general consultant for cryptanalysis at Bletchley Park.

Alexander wrote of Turing's contribution:

In July 1942, Turing devised a technique termed (or jokingly ) for use against the Lorenz cipher messages produced by the Germans' new Geheimschreiber (secret writer) machine. This was a teleprinter rotor cipher attachment codenamed Tunny at Bletchley Park. Turingery was a method of wheel-breaking, i.e., a procedure for working out the cam settings of Tunny's wheels. He also introduced the Tunny team to Tommy Flowers who, under the guidance of Max Newman, went on to build the Colossus computer, the world's first programmable digital electronic computer, which replaced a simpler prior machine (the Heath Robinson), and whose superior speed allowed the statistical decryption techniques to be applied usefully to the messages. Some have mistakenly said that Turing was a key figure in the design of the Colossus computer. Turingery and the statistical approach of Banburismus undoubtedly fed into the thinking about cryptanalysis of the Lorenz cipher, but he was not directly involved in the Colossus development.

Following his work at Bell Labs in the US, Turing pursued the idea of electronic enciphering of speech in the telephone system. In the latter part of the war, he moved to work for the Secret Service's Radio Security Service (later HMGCC) at Hanslope Park. At the park, he further developed his knowledge of electronics with the assistance of REME officer Donald Bayley. Together they undertook the design and construction of a portable secure voice communications machine codenamed . The machine was intended for different applications, but it lacked the capability for use with long-distance radio transmissions. In any case, Delilah was completed too late to be used during the war. Though the system worked fully, with Turing demonstrating it to officials by encrypting and decrypting a recording of a Winston Churchill speech, Delilah was not adopted for use. Turing also consulted with Bell Labs on the development of SIGSALY, a secure voice system that was used in the later years of the war.

Early computers and the Turing test

Plaque, 78 High Street, Hampton

Between 1945 and 1947, Turing lived in Hampton, London, while he worked on the design of the ACE (Automatic Computing Engine) at the National Physical Laboratory (NPL). He presented a paper on 19 February 1946, which was the first detailed design of a stored-program computer. Von Neumann's incomplete First Draft of a Report on the EDVAC had predated Turing's paper, but it was much less detailed and, according to John R. Womersley, Superintendent of the NPL Mathematics Division, it "contains a number of ideas which are Dr. Turing's own".

Although ACE was a feasible design, the effect of the Official Secrets Act surrounding the wartime work at Bletchley Park made it impossible for Turing to explain the basis of his analysis of how a computer installation involving human operators would work. This led to delays in starting the project and he became disillusioned. In late 1947 he returned to Cambridge for a sabbatical year during which he produced a seminal work on Intelligent Machinery that was not published in his lifetime. While he was at Cambridge, the Pilot ACE was being built in his absence. It executed its first program on 10 May 1950, and a number of later computers around the world owe much to it, including the English Electric DEUCE and the American Bendix G-15. The full version of Turing's ACE was not built until after his death.

According to the memoirs of the German computer pioneer Heinz Billing from the Max Planck Institute for Physics, published by Genscher, Düsseldorf, there was a meeting between Turing and Konrad Zuse. It took place in Göttingen in 1947. The interrogation had the form of a colloquium. Participants were Womersley, Turing, Porter from England and a few German researchers like Zuse, Walther, and Billing (for more details see Herbert Bruderer, Konrad Zuse und die Schweiz).

In 1948, Turing was appointed reader in the Mathematics Department at the Victoria University of Manchester. A year later, he became deputy director of the Computing Machine Laboratory, where he worked on software for one of the earliest stored-program computers-the Manchester Mark 1. Turing wrote the first version of the Programmer's Manual for this machine, and was recruited by Ferranti as a consultant in the development of their commercialised machine, the Ferranti Mark 1. He continued to be paid consultancy fees by Ferranti until his death. During this time, he continued to do more abstract work in mathematics, and in " Computing Machinery and Intelligence" (, October 1950), Turing addressed the problem of artificial intelligence, and proposed an experiment that became known as the Turing test, an attempt to define a standard for a machine to be called "intelligent". The idea was that a computer could be said to "think" if a human interrogator could not tell it apart, through conversation, from a human being. In the paper, Turing suggested that rather than building a program to simulate the adult mind, it would be better to produce a simpler one to simulate a child's mind and then to subject it to a course of education. A reversed form of the Turing test is widely used on the Internet; the CAPTCHA test is intended to determine whether the user is a human or a computer.

In 1948, Turing, working with his former undergraduate colleague, D.G. Champernowne, began writing a chess program for a computer that did not yet exist. By 1950, the program was completed and dubbed the Turochamp. In 1952, he tried to implement it on a Ferranti Mark 1, but lacking enough power, the computer was unable to execute the program. Instead, Turing "ran" the program by flipping through the pages of the algorithm and carrying out its instructions on a chessboard, taking about half an hour per move. The game was recorded. According to Garry Kasparov, Turing's program "played a recognizable game of chess". The program lost to Turing's colleague Alick Glennie, although it is said that it won a game against Champernowne's wife, Isabel.

His Turing test was a significant, characteristically provocative, and lasting contribution to the debate regarding artificial intelligence, which continues after more than half a century.

Pattern formation and mathematical biology

When Turing was 39 years old in 1951, he turned to mathematical biology, finally publishing his masterpiece " The Chemical Basis of Morphogenesis" in January 1952. He was interested in morphogenesis, the development of patterns and shapes in biological organisms. He suggested that a system of chemicals reacting with each other and diffusing across space, termed a reaction-diffusion system, could account for "the main phenomena of morphogenesis". He used systems of partial differential equations to model catalytic chemical reactions. For example, if a catalyst A is required for a certain chemical reaction to take place, and if the reaction produced more of the catalyst A, then we say that the reaction is autocatalytic, and there is positive feedback that can be modelled by nonlinear differential equations. Turing discovered that patterns could be created if the chemical reaction not only produced catalyst A, but also produced an inhibitor B that slowed down the production of A. If A and B then diffused through the container at different rates, then you could have some regions where A dominated and some where B did. To calculate the extent of this, Turing would have needed a powerful computer, but these were not so freely available in 1951, so he had to use linear approximations to solve the equations by hand. These calculations gave the right qualitative results, and produced, for example, a uniform mixture that oddly enough had regularly spaced fixed red spots. The Russian biochemist Boris Belousov had performed experiments with similar results, but could not get his papers published because of the contemporary prejudice that any such thing violated the second law of thermodynamics. Belousov was not aware of Turing's paper in the Philosophical Transactions of the Royal Society.

Although published before the structure and role of DNA was understood, Turing's work on morphogenesis remains relevant today and is considered a seminal piece of work in mathematical biology. One of the early applications of Turing's paper was the work by James Murray explaining spots and stripes on the fur of cats, large and small. Further research in the area suggests that Turing's work can partially explain the growth of "feathers, hair follicles, the branching pattern of lungs, and even the left-right asymmetry that puts the heart on the left side of the chest". In 2012, Sheth, et al. found that in mice, removal of Hox genes causes an increase in the number of digits without an increase in the overall size of the limb, suggesting that Hox genes control digit formation by tuning the wavelength of a Turing-type mechanism. Later papers were not available until Collected Works of A. M. Turing was published in 1992.

A study conducted in 2023 confirmed Turing's mathematical model hypothesis. Presented by the American Physical Society, the experiment involved growing chia seeds in even layers within trays, later adjusting the available moisture. Researchers experimentally tweaked the factors which appear in the Turing equations, and, as a result, patterns resembling those seen in natural environments emerged. This is believed to be the first time that experiments with living vegetation have verified Turing's mathematical insight.

Personal life

In the 1940s, Turing became worried about losing his savings in the event of a German invasion. In order to protect it, he bought two silver bars weighing 3,200 oz (90 kg) and worth £250 (in 2022, £8,000 adjusted for inflation, £48,000 at spot price) and buried them in a wood near Bletchley Park. Upon returning to dig them up, Turing found that he was unable to break his own code describing where exactly he had hidden them. This, along with the fact that the area had been renovated, meant that he never regained the silver.

Engagement

In 1941, Turing proposed marriage to Hut 8 colleague Joan Clarke, a fellow mathematician and cryptanalyst, but their engagement was short-lived. After admitting his homosexuality to his fiancée, who was reportedly "unfazed" by the revelation, Turing decided that he could not go through with the marriage.

Homosexuality and indecency conviction

In January 1952, Turing was 39 when he started a relationship with Arnold Murray, a 19-year-old unemployed man. Just before Christmas, Turing was walking along Manchester's Oxford Road when he met Murray just outside the Regal Cinema and invited him to lunch. On 23 January, Turing's house was burgled. Murray told Turing that he and the burglar were acquainted, and Turing reported the crime to the police. During the investigation, he acknowledged a sexual relationship with Murray. Homosexual acts were criminal offences in the United Kingdom at that time, and both men were charged with " gross indecency" under Section 11 of the Criminal Law Amendment Act 1885. Initial committal proceedings for the trial were held on 27 February during which Turing's solicitor "reserved his defence", i.e., did not argue or provide evidence against the allegations. The proceedings were held at the Sessions House in Knutsford.

Turing was later convinced by the advice of his brother and his own solicitor, and he entered a plea of guilty. The case, Regina v. Turing and Murray, was brought to trial on 31 March 1952. Turing was convicted and given a choice between imprisonment and probation. His probation would be conditional on his agreement to undergo hormonal physical changes designed to reduce libido, known as " chemical castration". He accepted the option of injections of what was then called stilboestrol (now known as diethylstilbestrol or DES), a synthetic oestrogen; this feminization of his body was continued for the course of one year. The treatment rendered Turing impotent and caused breast tissue to form. In a letter, Turing wrote that "no doubt I shall emerge from it all a different man, but quite who I've not found out". Murray was given a conditional discharge.

Turing's conviction led to the removal of his security clearance and barred him from continuing with his cryptographic consultancy for the Government Communications Headquarters (GCHQ), the British signals intelligence agency that had evolved from GC&CS in 1946, though he kept his academic job. His trial took place only months after the defection to the Soviet Union of Guy Burgess and Donald Maclean in summer 1951 after which the Foreign Office started to consider anyone known to be homosexual as a potential security risk.

Turing was denied entry into the United States after his conviction in 1952, but was free to visit other European countries. In the summer of 1952 he visited Norway which was more tolerant of homosexuals. Among the various men he met there was one named Kjell Carlson. Kjell intended to visit Turing in the UK but the authorities intercepted Kjell's postcard detailing his travel arrangements and were able to intercept and deport him before the two could meet. It was also during this time that Turing started consulting a psychiatrist, Dr Franz Greenbaum, with whom he got on well and who subsequently became a family friend.

A blue plaque on the house at 43 Adlington Road, Wilmslow, where Turing lived and died[174]

On 8 June 1954, at his house at 43 Adlington Road, Wilmslow, Turing's housekeeper found him dead. A post mortem was held that evening which determined that he had died the previous day at the age of 41 with Cyanide poisoning cited as the cause of death. When his body was discovered, an apple lay half-eaten beside his bed, and although the apple was not tested for cyanide, it was speculated that this was the means by which Turing had consumed a fatal dose.

Turing's brother John identified the body the following day and took the advice given by Dr. Greenbaum to accept the verdict of the inquest as there was little prospect of establishing that the death was accidental. The inquest was held the following day which determined the cause of death to be suicide. Turing's remains were cremated at Woking Crematorium just two days later on 12 June 1954 with just three people attending and his ashes were scattered in the gardens of the crematorium, just as his father's had been. Turing's mother was on holiday in Italy at the time of his death and returned home after the inquest. She never accepted the verdict of suicide.

Andrew Hodges and another biographer, David Leavitt, have both speculated that Turing was re-enacting a scene from the Walt Disney film Snow White and the Seven Dwarfs (1937), his favourite fairy tale. Both men noted that (in Leavitt's words) he took "an especially keen pleasure in the scene where the Wicked Queen immerses her apple in the poisonous brew".

Philosopher Jack Copeland has questioned various aspects of the coroner's historical verdict. He suggested an alternative explanation for the cause of Turing's death: the accidental inhalation of cyanide fumes from an apparatus used to electroplate gold onto spoons. The potassium cyanide was used to dissolve the gold. Turing had such an apparatus set up in his tiny spare room. Copeland noted that the autopsy findings were more consistent with inhalation than with ingestion of the poison. Turing also habitually ate an apple before going to bed, and it was not unusual for the apple to be discarded half-eaten. Furthermore, Turing had reportedly borne his legal setbacks and hormone treatment (which had been discontinued a year previously) "with good humour" and had shown no sign of despondency before his death. He even set down a list of tasks that he intended to complete upon returning to his office after the holiday weekend. Turing's mother believed that the ingestion was accidental, resulting from her son's careless storage of laboratory chemicals. Biographer Andrew Hodges theorised that Turing deliberately left the nature of his death ambiguous in order to shield his mother from the knowledge that he had killed himself. Doubts on the suicide thesis have been also cast by John W. Dawson Jr. who, in his review of Hodges' book, recalls "Turing's vulnerable position in the Cold War political climate" and points out that "Turing was found dead by a maid, who discovered him 'lying neatly in his bed'-hardly what one would expect of "a man fighting for life against the suffocation induced by cyanide poisoning." Turing had given no hint of suicidal inclinations to his friends and had made no effort to put his affairs in order.

Turing's OBE currently held in Sherborne School archives

It has been suggested that Turing's belief in fortune-telling may have caused his depressed mood. As a youth, Turing had been told by a fortune-teller that he would be a genius. In mid-May 1954, shortly before his death, Turing again decided to consult a fortune-teller during a day-trip to St Annes-on-Sea with the Greenbaum family. According to the Greenbaums' daughter, Barbara:

But it was a lovely sunny day and Alan was in a cheerful mood and off we went... Then he thought it would be a good idea to go to the Pleasure Beach at Blackpool. We found a fortune-teller's tent and Alan said he'd like to go in[,] so we waited around for him to come back... And this sunny, cheerful visage had shrunk into a pale, shaking, horror-stricken face. Something had happened. We don't know what the fortune-teller said but he obviously was deeply unhappy. I think that was probably the last time we saw him before we heard of his suicide.

Government apology and pardon

In August 2009, British programmer John Graham-Cumming started a petition urging the British government to apologise for Turing's prosecution as a homosexual. The petition received more than 30,000 signatures. The prime minister, Gordon Brown, acknowledged the petition, releasing a statement on 10 September 2009 apologising and describing the treatment of Turing as "appalling":

Thousands of people have come together to demand justice for Alan Turing and recognition of the appalling way he was treated. While Turing was dealt with under the law of the time and we can't put the clock back, his treatment was of course utterly unfair and I am pleased to have the chance to say how deeply sorry I and we all are for what happened to him ... So on behalf of the British government, and all those who live freely thanks to Alan's work I am very proud to say: we're sorry, you deserved so much better.

In December 2011, William Jones and his member of Parliament, John Leech, created an e-petition requesting that the British government pardon Turing for his conviction of "gross indecency":

The petition gathered over 37,000 signatures, and was submitted to Parliament by the Manchester MP John Leech but the request was discouraged by Justice Minister Lord McNally, who said:

John Leech, the MP for Manchester Withington (2005-15), submitted several bills to Parliament and led a high-profile campaign to secure the pardon. Leech made the case in the House of Commons that Turing's contribution to the war made him a national hero and that it was "ultimately just embarrassing" that the conviction still stood. Leech continued to take the bill through Parliament and campaigned for several years, gaining the public support of numerous leading scientists, including Stephen Hawking. At the British premiere of a film based on Turing's life, The Imitation Game, the producers thanked Leech for bringing the topic to public attention and securing Turing's pardon. Leech is now regularly described as the "architect" of Turing's pardon and subsequently the Alan Turing Law which went on to secure pardons for 75,000 other men and women convicted of similar crimes.

On 26 July 2012, a bill was introduced in the House of Lords to grant a statutory pardon to Turing for offences under section 11 of the Criminal Law Amendment Act 1885, of which he was convicted on 31 March 1952. Late in the year in a letter to The Daily Telegraph, the physicist Stephen Hawking and 10 other signatories including the Astronomer Royal Lord Rees, President of the Royal Society Sir Paul Nurse, Lady Trumpington (who worked for Turing during the war) and Lord Sharkey (the bill's sponsor) called on Prime Minister David Cameron to act on the pardon request. The government indicated it would support the bill, and it passed its third reading in the House of Lords in October.

At the bill's second reading in the House of Commons on 29 November 2013, Conservative MP Christopher Chope objected to the bill, delaying its passage. The bill was due to return to the House of Commons on 28 February 2014, but before the bill could be debated in the House of Commons, the government elected to proceed under the royal prerogative of mercy. On 24 December 2013, Queen Elizabeth II signed a pardon for Turing's conviction for "gross indecency", with immediate effect. Announcing the pardon, Lord Chancellor Chris Grayling said Turing deserved to be "remembered and recognised for his fantastic contribution to the war effort" and not for his later criminal conviction. The Queen officially pronounced Turing pardoned in August 2014. The Queen's action is only the fourth royal pardon granted since the conclusion of the Second World War. Pardons are normally granted only when the person is technically innocent, and a request has been made by the family or other interested party; neither condition was met in regard to Turing's conviction.

In September 2016, the government announced its intention to expand this retroactive exoneration to other men convicted of similar historical indecency offences, in what was described as an " Alan Turing law". The Alan Turing law is now an informal term for the law in the United Kingdom, contained in the Policing and Crime Act 2017, which serves as an amnesty law to retroactively pardon men who were cautioned or convicted under historical legislation that outlawed homosexual acts. The law applies in England and Wales.

On 19 July 2023, following an apology to LGBT veterans from the UK Government, Defence Secretary Ben Wallace suggested Turing should be honoured with a permanent statue on the fourth plinth of Trafalgar Square, describing Dr Turing as "probably the greatest war hero, in my book, of the Second World War, [whose] achievements shortened the war, saved thousands of lives, helped defeat the Nazis. And his story is a sad story of a society and how it treated him."

Publications

References

1. Alan Turing publications indexed by Google Scholar

2. Alan Turing at the Mathematics Genealogy Project

3. ^ Gandy, Robin Oliver (1953). On axiomatic systems in mathematics and theories in physics (PhD thesis). University of Cambridge. doi:10.17863/CAM.16125. EThOS uk.bl.ethos.590164. Archived from the original on 9 December 2017.

4. Bowen, Jonathan P. (2019). "The Impact of Alan Turing: Formal Methods and Beyond". In Bowen, Jonathan P.; Liu, Zhiming; Zhang, Zili (eds.). Engineering Trustworthy Software Systems (PDF). Lecture Notes in Computer Science. Vol. 11430. Cham: Springer. pp. 202-235. doi:10.1007/978-3-030-17601-3_5. ISBN 978-3-030-17600-6. S2CID 121295850. Archived (PDF) from the original on 9 October 2022.

5. ^ Newman, M.H.A. (1955). "Alan Mathison Turing. 1912-1954". Biographical Memoirs of Fellows of the Royal Society. 1: 253-263. doi:10.1098/rsbm.1955.0019. JSTOR 769256. S2CID 711366.

6. ^ Gray, Paul (29 March 1999). "Computer Scientist: Alan Turing". Time. Archived from the original on 19 January 2011. Providing a blueprint for the electronic digital computer. The fact remains that everyone who taps at a keyboard, opening a spreadsheet or a word-processing program, is working on an incarnation of a Turing machine.

7. ^ Copeland, Jack (18 June 2012). "Alan Turing: The codebreaker who saved 'millions of lives'". BBC News Technology. Archived from the original on 11 October 2014.

8. A number of sources state that Winston Churchill said that Turing made the single biggest contribution to Allied victory in the war against Nazi Germany. However, both the ^ Churchill Centre and Turing's biographer Andrew Hodges have stated they know of no documentary evidence to support this claim, nor of the date or context in which Churchill supposedly said it, and the Churchill Centre lists it among their Churchill 'Myths', see and Hodges, Andrew. "Part 4: The Relay Race". Update to Alan Turing: The Enigma. Archived from the original on 20 January 2015. A BBC News profile piece that repeated the Churchill claim has subsequently been amended to say there is no evidence for it. See Spencer, Clare (11 September 2009). "Profile: Alan Turing". BBC News. Archived from the original on 13 December 2017. Update 13 February 2015 Official war historian Harry Hinsley estimated that this work shortened the war in Europe by more than two years but added the caveat that this did not account for the use of the atomic bomb and other eventualities. Hinsley, Harry (1996) [1993], The Influence of ULTRA in the Second World War, Keith Lockstone's home page Transcript of a lecture given on Tuesday 19 October 1993 at Cambridge University

9. ^ Milinkovitch, Michel C.; Jahanbakhsh, Ebrahim; Zakany, Szabolcs (16 October 2023). "The Unreasonable Effectiveness of Reaction Diffusion in Vertebrate Skin Color Patterning". Annual Review of Cell and Developmental Biology. 39 (1): 145-174. doi:10.1146/annurev-cellbio-120319-024414. ISSN 1081-0706. PMID 37843926.

10. Hodges 1983, p. 5

11. ^ "The Alan Turing Internet Scrapbook". Alan Turing: The Enigma. Archived from the original on 14 June 2012.

12. ^ Maguire, Phil (23 June 2012). "An Irishman's Diary". The Irish Times. p. 5.

13. ^ Irish Marriages 1845-1958 / Dublin South, Dublin, Ireland / Group Registration ID 1990366, SR District/Reg Area, Dublin South

14. ^ Plaque #381 on Open Plaques

15. ^ "Plaque unveiled at Turing's home in St Leonards". Hastings & St. Leonards Observer. 29 June 2012. Archived from the original on 12 September 2017.

16. ^ "St Leonards plaque marks Alan Turing's early years". BBC News. 25 June 2012. Archived from the original on 3 December 2017.

17. ^ Cawthorne, Nigel (2014). Alan Turing : the enigma man. London: Arcturus Publishing. p. 18. ISBN 978-1-78404-535-7. OCLC 890938716.

18. ^ "The Shirburnian" (PDF). Archived (PDF) from the original on 9 October 2022.

19. ^ The Alyson Almanac: A Treasury of Information for the Gay and Lesbian Community. Alyson Publications. 1989. p. 192. ISBN 978-0-932870-19-3. After his first love, Christopher Morcom, died of tuberculosis ...

20. ^ Hodges, Andrew (1992). Alan Turing: The Enigma. Vintage. p. 35. ISBN 978-0-09-911641-7. This was first love, which Alan would himself come to regard as the first of many for others of his own sex.

21. ^ Tekhnema: Journal of Philosophy and Technology. American University of Paris. 1995. p. 57. ... Turing's first platonic love, Christopher Morcom ...

22. ^ Caryl, Christian (19 December 2014). "Poor Imitation of Alan Turing". New York Review of Books. Archived from the original on 7 January 2015.

23. ^ Hassall, Rachel (2012-2013). "The Sherborne Formula: The Making of Alan Turing" (PDF). Vivat!. Archived from the original (PDF) on 15 April 2014.

24. ^ Teuscher, Christof, ed. (2004). Alan Turing: Life and Legacy of a Great Thinker. Springer-Verlag. ISBN 978-3-540-20020-8. OCLC 53434737.

25. ^ "Alan Turing and the 'Nature of Spirit'". oldshirburnian.org.uk. 15 August 2020.

26. ^

27. ^ "Inflation calculator".

28. ^ "AMT-B-10 | the Turing Digital Archive".

29. ^ Aldrich, John (December 2009). "England and Continental Probability in the Inter-War Years" (PDF). Electronic Journ@l for History of Probability and Statistics. 5 (2): 7-11.

30. ^ Turing, Dermot (2015). Prof: Alan Turing Decoded. The History Press. p. 69. ISBN 9781841656434.

31. ^ Zabell, S. L. (1995). "Alan Turing and the Central Limit Theorem". The American Mathematical Monthly. 102 (6): 483-494. doi:10.1080/00029890.1995.12004608.

32. ^

33. ^ Grime, James (February 2012). "What Did Turing Do for Us?". NRICH. University of Cambridge. Archived from the original on 4 March 2016.

34. "von Neumann ... firmly emphasised to me, and to others I am sure, that the fundamental conception is owing to Turing-insofar as not anticipated by Babbage, Lovelace and others." Letter by ^ Stanley Frankel to Brian Randell, 1972, quoted in Jack Copeland (2004) The Essential Turing, p. 22.

35. ^ Turing, A.M. (1939). "Systems of Logic Based on Ordinals". Proceedings of the London Mathematical Society. s2-45: 161-228. doi:10.1112/plms/s2-45.1.161. hdl:21.11116/0000-0001-91CE-3.

36. ^ Turing, Alan (1938). Systems of Logic Based on Ordinals (PhD thesis). Princeton University. doi:10.1112/plms/s2-45.1.161. hdl:21.11116/0000-0001-91CE-3. ProQuest 301792588.

37. ^ Turing, A.M. (1938). "Systems of Logic Based on Ordinals" (PDF). Archived from the original (PDF) on 23 October 2012.

38. ^ John Von Neumann: The Scientific Genius Who Pioneered the Modern Computer, Game Theory, Nuclear Deterrence, and Much More, Norman MacRae, 1999, American Mathematical Society, Chapter 8

39. Copeland, 2006 p. 378.

40. Collins, Jeremy (24 June 2020). "Alan Turing and the Hidden Heroes of Bletchley Park: A Conversation with Sir John Dermot Turing". New Orleans: The National WWII Museum.

41. ^ Turing, Alan M.; Bayley, D. (2012). "Report on Speech Secrecy System DELILAH, a Technical Description Compiled by A. M. Turing and Lieutenant D. Bayley REME, 1945-1946". Cryptologia. 36 (4): 295-340. doi:10.1080/01611194.2012.713803. ISSN 0161-1194. S2CID 205488183.

42. ^ Turing, Alan M. (1940). The Prof's Book: Turing's Treatise on the Enigma. In late 1940 Alan Turing wrote a report describing the methods he and his colleagues at Bletchley Park had used to break into the German Enigma cipher systems. At Bletchley it was known as 'the Prof's Book.' A copy of this handbook was at last released from secrecy by the American National Security Agency in April 1996, under the title Turing's Treatise on the Enigma. Subsequently, a much better original copy was released by the (British) National Archives, box HW 25/3. This also revealed a title which had been lost in the American copy: Mathematical theory of ENIGMA machine. (Though, oddly, the report does not actually have any mathematical theory.)

43. ^ Hilton, Peter. "A Century of Mathematics in America, Part 1, Reminiscences of Bletchley Park" (PDF). Archived (PDF) from the original on 29 August 2019.

44. ^ Hilton, Peter. "NOVA | Transcripts | Decoding Nazi Secrets | PBS". PBS. Archived from the original on 29 August 2019.

45. ^ Hodges, Andrew. "Alan Turing: a short biography". Alan Turing: The Enigma. Archived from the original on 14 September 2013.

46. ^ Graham-Cumming, John (10 March 2010). "Alan Turing: a short biography". The Guardian. Archived from the original on 8 November 2014.

47. See for example ^ Richelson, Jeffery T. (1997). A Century of Spies: Intelligence in the Twentieth Century. New York: Oxford University Press. p. 296. and Hartcup, Guy (2000). The Effect of Science on the Second World War. Basingstoke, Hampshire: Macmillan Press. pp. 96-99.

48. ^ Hinsley, Harry (1996) [1993], The Influence of ULTRA in the Second World War Transcript of a lecture given on Tuesday 19 October 1993 at Cambridge University

49. ^ Jack Good in "The Men Who Cracked Enigma", 2003: with his caveat: "if my memory is correct".

50. Hodges 1983, p. 218

51. Hodges 1983, p. 221

52. Copeland, ^ The Essential Turing, pp. 336-337 Archived 18 February 2015 at the Wayback Machine.

53. ^ Copeland, Jack; Proudfoot, Diane (May 2004). "Alan Turing, Codebreaker and Computer Pioneer". alanturing.net. Archived from the original on 9 July 2007.

54. ^ Good, Jack; Michie, Donald; Timms, Geoffrey (1945), General Report on Tunny: With Emphasis on Statistical Methods, Part 3 Organisation: 38 Wheel-breaking from Key, Page 293, UK Public Record Office HW 25/4 and HW 25/5, archived from the original on 21 April 2019

55. ^ Turing, Alan M. (2001). "Visit to National Cash Register Corporation of Dayton, Ohio". Cryptologia. 25 (1): 1-10. doi:10.1080/0161-110191889734. S2CID 14207094.

56. ^ Harper, John (Spring 2023). "Delilah Voice Secrecy System". Resurrection: The Journal of the Computer Conservation Society (101). The Computer Conservation Society: 8-9.

57. ^ Harper, John (Summer 2023). "Delilah Voice Secrecy System [part 2]: The Design, Development and Commissioning of Delilah in 1943 - 1945". Resurrection: The Journal of the Computer Conservation Society (102). The Computer Conservation Society: 16-19.

58. ^ Plaque #1619 on Open Plaques

59. ^ Randell, Brian (1980). "A History of Computing in the Twentieth Century: Colossus" (PDF). Archived (PDF) from the original on 27 January 2012. citing Womersley, J.R. (13 February 1946). "'ACE' Machine Project". Executive Committee, National Physical Laboratory, Teddington, Middlesex.

60. ^ Hodges, Andrew (2014). Alan Turing: The Enigma. Princeton University Press. p. 416. ISBN 978-0-691-16472-4.

61. ^ Bruderer, Herbert. "Did Alan Turing interrogate Konrad Zuse in Göttingen in 1947?" (PDF). Archived (PDF) from the original on 21 May 2013.

62. ^ Swinton, Jonathan (2019). Alan Turing's Manchester. Manchester: Infang Publishing. ISBN 978-0-9931789-2-4. Archived from the original on 17 February 2019.

63. ^ Turing, A.M. (1948). "Rounding-Off Errors in Matrix Processes". The Quarterly Journal of Mechanics and Applied Mathematics. 1: 287-308. doi:10.1093/qjmam/1.1.287. hdl:10338.dmlcz/103139.

64. ^ Harnad, Stevan (2008). "The Annotation Game: On Turing (1950) on Computing, Machinery and Intelligence". In Epstein, Robert; Peters, Grace (eds.). Parsing the Turing Test: Philosophical and Methodological Issues in the Quest for the Thinking Computer. Springer. ISBN 9781402067082. Archived from the original on 18 October 2017.

65. ^ "Alan Turing vs Alick Glennie (1952) "Turing Test"". Chessgames.com. Archived from the original on 19 February 2006.

66. ^ Pinar Saygin, A.; Cicekli, I.; Akman, V. (2000). "Turing Test: 50 Years Later". Minds and Machines. 10 (4): 463-518. doi:10.1023/A:1011288000451. hdl:11693/24987. S2CID 990084.

67. ^ Turing, Alan M. (14 August 1952). "The Chemical Basis of Morphogenesis". Philosophical Transactions of the Royal Society of London B. 237 (641): 37-72. Bibcode:1952RSPTB.237...37T. doi:10.1098/rstb.1952.0012. S2CID 120437796.

68. ^ Murray, James D. (March 1988). "How the Leopard Gets Its Spots". Scientific American. 258 (3): 80-87. Bibcode:1988SciAm.258c..80M. doi:10.1038/scientificamerican0388-80. JSTOR 24989019.

69. ^ Vogel, G. (2012). "Turing Pattern Fingered for Digit Formation". Science. 338 (6113): 1406. Bibcode:2012Sci...338.1406V. doi:10.1126/science.338.6113.1406. PMID 23239707.

70. ^ Sheth, R.; Marcon, L.; Bastida, M.F.; Junco, M.; Quintana, L.; Dahn, R.; Kmita, M.; Sharpe, J.; Ros, M.A. (2012). "Hox Genes Regulate Digit Patterning by Controlling the Wavelength of a Turing-Type Mechanism". Science. 338 (6113): 1476-1480. Bibcode:2012Sci...338.1476S. doi:10.1126/science.1226804. PMC 4486416. PMID 23239739.

71. ^

72. ^ Hodges, Andrew (2012). Alan Turing: The Enigma. Princeton University Press. p. xxviii. ISBN 978-0-691-15564-7.

73. Anon (2021). "Turing's House: Copper Folly, 43 Adlington Road, Wilmslow, Cheshire, SK9 2BJ" (PDF). savills.com. Archived from the original (PDF) on 3 July 2021.

74. ^ Leavitt 2007, p. 140 and Hodges 1983, pp. 149, 489

75. ^ Dawson Jr., John W. (December 1985). ""Review of Andrew Hodges. Alan Turing: the enigma"". Journal of Symbolic Logic. 50 (4): 1065-1067. doi:10.2307/2273992. JSTOR 2273992.

76. ^ The petition was only open to UK citizens.

77. ^ "Full text of the Prime Minister's apology". Archived from the original on 9 November 2012.

78. ^ "John Leech secures historic deal with Government on 'Alan Turing Law'". outnewsglobal.com. 20 October 2016.

Works cited

Alexander, C. Hugh O'D. "Cryptographic History of Work on the German Naval Enigma". The National Archives, Kew, Reference HW 25/1.

Church, Alonzo (1936). "An Unsolvable Problem of Elementary Number Theory". American Journal of Mathematics. 58 (2): 345-363. doi:10.2307/2371045. ISSN 0002-9327. JSTOR 2371045.

Copeland, B. Jack (2004a). "Colossus: Its Origins and Originators". IEEE Annals of the History of Computing. 26 (4): 38-45. doi:10.1109/MAHC.2004.26. S2CID 20209254.

Copeland, B. Jack, ed. (2004b). The Essential Turing. Oxford: Oxford University Press. ISBN 978-0-19-825079-1. OCLC 156728127.

Mahon, A. P. (1945). "The History of Hut Eight 1939-1945". UK National Archives Reference HW 25/2.

Oakley, Brian, ed. (2006). The Bletchley Park War Diaries: July 1939 - August 1945 (2.6 ed.). Wynne Press.

Turing, A. M. (1937) [Delivered to the Society November 1936]. "On Computable Numbers, with an Application to the Entscheidungsproblem" (PDF). Proceedings of the London Mathematical Society. 2. Vol. 42. pp. 230-65. doi:10.1112/plms/s2-42.1.230.

Further reading

Copeland, B. Jack (ed.). "The Mind and the Computing Machine: Alan Turing and others". The Rutherford Journal.

Copeland, B. Jack (ed.). "Alan Turing: Father of the Modern Computer". The Rutherford Journal.

(Subscription or Hodges, Andrew (2004). "Turing, Alan Mathison". Oxford Dictionary of National Biography (online ed.). Oxford University Press. doi:10.1093/ref:odnb/36578. UK public library membership required.)

Hodges, Andrew (2007). "Alan Turing". In Edward N. Zalta (ed.). Stanford Encyclopedia of Philosophy (Winter 2009 ed.). Stanford University.

Gray, Paul (29 March 1999). "Computer Scientist: Alan Turing". Time. Archived from the original on 16 October 2007.

O'Connell, H; Fitzgerald, M (2003). "Did Alan Turing have Asperger's syndrome?". Irish Journal of Psychological Medicine. 20 (1). Irish Institute of Psychological Medicine: 28-31. doi:10.1017/s0790966700007503. ISSN 0790-9667. PMID 30440230. S2CID 53563123.

O'Connor, John J.; Robertson, Edmund F., "Alan Mathison Turing", MacTutor History of Mathematics Archive, University of St Andrews

Babbage, Charles (1864). Campbell-Kelly, Martin (ed.). Passages from the life of a philosopher. Rough Draft Printing (published 2008). ISBN 978-1-60386-092-5.

Beniger, James (1986). The control revolution: technological and economic origins of the information society. Cambridge, Massachusetts: Harvard University Press. ISBN 978-0-674-16986-9.

Bodanis, David (2005). Electric Universe: How Electricity Switched on the Modern World. New York: Three Rivers Press. ISBN 978-0-307-33598-2. OCLC 61684223.

Bruderer, Herbert (2012). "Die Maschinen von Charles Babbage, Alan Turing und John von Neumann". Konrad Zuse und die Schweiz. Wer hat den Computer erfunden? (in German). München: Oldenbourg Wissenschaftsverlag. doi:10.1524/9783486716658. ISBN 978-3-486-71366-4.

Campbell-Kelly, Martin; Aspray, William (1996). Computer: A History of the Information Machine. New York: Basic Books. ISBN 978-0-465-02989-1.

Chandler, Alfred (1977). The Visible Hand: The Managerial Revolution in American Business. Cambridge, Massachusetts: Belknap Press. ISBN 978-0-674-94052-9.

Copeland, B. Jack, ed. (2005). Alan Turing's Automatic Computing Engine. Oxford: Oxford University Press. ISBN 978-0-19-856593-2. OCLC 224640979.

Copeland, B. Jack; Bowen, Jonathan P.; Wilson, Robin; Sprevak, Mark (2017). The Turing Guide. Oxford University Press. ISBN 978-0-19-874783-3.

Gleick, James (2011). The Information: A History, a Theory, a Flood. New York: Pantheon. ISBN 978-0-375-42372-7.

Hodges, Andrew (2014). Alan Turing: The Enigma. Princeton University Press. ISBN 978-0-691-16472-4. (originally published in 1983); basis of the film The Imitation Game

Lubar, Steven (1993). . Boston, Massachusetts and New York: Houghton Mifflin. ISBN 978-0-395-57042-5.

Petzold, Charles (2008). The Annotated Turing: A Guided Tour through Alan Turing's Historic Paper on Computability and the Turing Machine. Indianapolis: Wiley Publishing. ISBN 978-0-470-22905-7.

Smith, Roger (1997). Fontana History of the Human Sciences. London: Fontana.

Turing, Sara Stoney (1959). Alan M Turing. W Heffer. Turing's mother, who survived him by many years, wrote this 157-page biography of her son, glorifying his life. It was published in 1959, and so could not cover his war work. Scarcely 300 copies were sold (Sara Turing to Lyn Newman, 1967, Library of St John's College, Cambridge). The six-page foreword by Lyn Irvine includes reminiscences and is more frequently quoted. It was re-published by Cambridge University Press in 2012, to honour the centenary of his birth, and included a new foreword by Martin Davis, as well as a never-before-published memoir by Turing's older brother John F. Turing.

Turing, Sara (2012). Alan M. Turing. Cambridge University Press. ISBN 978-1-107-02058-0. (originally published in 1959 by W. Heffer & Sons, Ltd)

Whitemore, Hugh; Hodges, Andrew (1988). Breaking the code. S. French. This 1986 Hugh Whitemore play tells the story of Turing's life and death. In the original West End and Broadway runs, Derek Jacobi played Turing and he recreated the role in a 1997 television film based on the play made jointly by the BBC and WGBH, Boston. The play is published by Amber Lane Press, Oxford, ASIN: B000B7TM0Q

Williams, Michael R. (1985). A History of Computing Technology. Englewood Cliffs, New Jersey: Prentice-Hall. ISBN 0-8186-7739-2.

Yates, David M. (1997). Turing's Legacy: A history of computing at the National Physical Laboratory 1945-1995. London: London Science Museum. ISBN 978-0-901805-94-2. OCLC 123794619.

External links

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Alan Mathison Turing (; 23 June 1912 - 7 June 1954) was an English mathematician, computer scientist, logician, cryptanalyst, philosopher and theoretical biologist. Turing was highly influential in the development of theoretical computer science, providing a formalisation of the concepts of algorithm and computation with the Turing machine, which can be considered a model of a general-purpose computer.

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Explicit documents prepared for the Oscar Wilde libel case have come to light, offering a revealing new glimpse of the double life led by the celebrated Irish writer.

The shocking witness statements, previously unseen, were drawn up by employees at Day Russell of the Strand, solicitors for the defence in Wilde's disastrous 1895 legal action against the Marquis of Queensberry. Most of the papers were filed away and never used in court.

While Wilde is remembered today as the dandy-about-town, sporting bespoke suits and habitually wearing a green carnation in his buttonhole, these statements - from chamber-maids, valets, bell-boys and even a lamp-wick seller portray his private life in lurid detail.

Seedy descriptions of Wilde's bedroom are included in the damaging file, which was instrumental in Wilde's downfall and formed the background for one of the most famous cases in British legal history.

Wilde took legal action against the Marquis, father of his lover, Lord Alfred Douglas, after he found a visiting card left by Queensberry at the Albermarle club. It was inscribed with the words: 'For Oscar Wilde posing Somdomite [ sic ]'.

The 52 pages of statements from 32 witnesses have never been published and are hand-written on heavy sheets of paper. They were picked up in a London junk shop for a pittance during the Fifties by a private collector whose widow is now selling them at Christie's on 6 June. The historic bundle, wrapped in pink string, is expected to fetch £12,000.

Among the more sordid details are those revealed by Margaret Cotta, a chambermaid at the Savoy Hotel, a favourite rendezvous for Wilde and his series of young male 'renters'. Describing a prolonged visit to the hotel by Wilde and Alfred Douglas, who was affectionately known as Bosie, Miss Cotta said she found a 'common boy, rough looking, about 14 years of age' in Wilde's bed, the sheets of which 'were always in a most disgusting state... [with] traces of vaseline, soil and semen'.

Instructions were given that the linen should be kept apart and washed separately. Miss Cotta added that a stream of page boys delivering letters were usually kissed by Wilde, who then tipped them two shillings and sixpence for their trouble.

Thomas Venning, a manuscripts specialist at Christie's, said the documents provided a new account of Wilde's undoing and had 'very detailed sexual content which was only mentioned in the trial euphemistically'.

The statements also show Wilde's carefree attitude to discovery. Wallis Grainger, an apprentice electrician from Oxford, told how Wilde took him to a cottage in nearby Goring-on-Thames which he had rented and where he wrote An Ideal Husband.

On the second or third night, said Grainger, Wilde 'came into my bedroom and woke me up and told me to come into his bedroom which was next door... he worked me up with his hand and made me spend in his mouth'. The former butler of the Marquis of Queensberry was in the next room.

On another occasion, during the Goring regatta, Gertrude Simmons, governess to Wilde's two sons, reported seeing him 'holding the arm of a boat boy called George Hughes and patting him very familiarly'. During the same visit she came across a carelessly discarded letter to Wilde from Bosie which was signed 'your own loving darling boy to do what you like with'.

Another statement came from a 20-year-old called Fred Atkins, who Wilde had met at the Café Royale. Atkins said Wilde 'took me to the hairdresser and had my hair curled'. Wilde later took him off to Paris as his secretary, Atkins said. The job involved 'writing out only half a page of a manuscript which took about 10 minutes' after which Wilde 'made improper proposals'.

Queensberry had used detectives to track down a circle of male prostitutes, and some of their statements are among those being sold. Wilde's action against Queensberry opened on 3 April 1895 at the Old Bailey but collapsed with a not guilty verdict. At noon on 5 April, the evidence gathered by solicitor Charles Russell was immediately forwarded to the Director of Public Prosecutions and Wilde was arrested on a charge of gross indecency.

On 24 May, after two further trials, he was sentenced to two years' imprisonment with hard labour, which broke his health. After his release he lived abroad as a bankrupt under the pseudonym Sebastian Melmoth. He died in Paris on 30 November 1900.

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Wilde's sex life exposed in explicit court files

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Explicit documents prepared for the Oscar Wilde libel case have come to light, offering a revealing new glimpse of the double life led by the celebrated Irish writer. The shocking witness statements, previously unseen, were drawn up by employees at Day Russell of the Strand, solicitors for the defence in Wilde's disastrous 1895 legal action against the Marquis of Queensberry.

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Why did Arthur C. Clarke choose to live in Sri Lanka?

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Answer (1 of 3): Arthur C. Clarke was gay and felt that that Sri Lanka was a safer place for him to live than in the UK as Sri Lanka was more tolerant of homosexuality than Britain was at the time. Clarke was apparently very upset by the treatment of Alan Turing by the British government and did...

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Sri Lankan authorities say British-born sci-fi writer Arthur C Clarke had been cleared of decade-old paedophilia allegations before his death last week.

Clarke was buried on Saturday in Colombo, where he had lived since 1956.

Obituary writers have resurrected 1998 accusations that he had sex with young boys in his adopted country.

But National Child Protection Authority (NCPA) chief Jagath Wellawatte said there was no case against the writer, who captured the world's imagination with 2001: A Space Odyssey and visions of extra-terrestrial civilisations.

"We had no case against Clarke and no one had come forward to say they were abused by him," Mr Wellawatte said.

The agency was established under new child protection laws enacted after the allegations against Clarke surfaced.

"We have not had any formal complaint or testimony from anyone saying they were abused by Sir Arthur," said NCPA investigator WTD Wijesena. "We cannot go on the basis of rumours."

The forerunner to the NCPA, the Presidential Task Force on the Prevention of Child Abuse, had in 1998 initiated an investigation into Clarke's conduct with the help of Interpol.

Police spent two-and-a-half hours recording a statement from Clarke in 1998, but no charges were brought against him.

Clarke, who died Wednesday at age 90, vehemently denied the allegations and also threatened to sue the British newspaper which made the charges following a "sting operation" by two undercover reporters.

Clarke said at the time that he was "disturbed to discover that there has been a long-standing conspiracy here in Sri Lanka to discredit [him] ... involving activists associated with child welfare organisations."

The accusations surfaced while Prince Charles was visiting Colombo and was due to confer a knighthood on Clarke. The investiture was eventually held two years later.

Upon Clarke's death, there were no official condolences from London. The High Commission in Colombo only briefly noted Clarke's death with "sadness" on its website.

- AFP

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Arthur C Clarke not a paedophile: Sri Lanka

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Sri Lankan authorities say British-born sci-fi writer Arthur C Clarke had been cleared of decade-old paedophilia allegations before his death last week. Clarke was buried on Saturday in Colombo, where he had lived since 1956. Obituary writers have resurrected 1998 accusations that he had sex with young boys in his adopted country.

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Out of the Blue opens with Arthur playing table tennis. This seems slightly odd, but all becomes clear when he explains that his daily table-tennis partner - at the Otter's Club, Colombo - saw fish falling from the sky.

There's some classic eye-witness interviews in this one. Joe Alpin recalls a strange event during WW2. "The sky suddenly darkened. And then the frogs came. Millions of them. Raining out of the sky." Possibly Joe overestimated the number a little, as millions seem a little excessive - although he did claim it rained frogs for well over an hour, so there must have been quite a few.

Mrs Sylvia Mowday looks just the sort of sensible, late middle-aged woman that you wouldn't think would make up a strange story simply for a bit of publicity, so maybe her froggy tale was true. "We heard something thudding against the umbrella. When we looked, to our amazement it was a shower of frogs. There were hundreds of them." This happened in the 1950's - a few years after Joe's sighting - and it's interesting that Mrs Mowday only mentions hundreds. Had raining frogs been curtailed since the war, or was she simply better at counting than Joe?!

Although reports of frogs falling from the sky are quite common, so are tales of fish descending from the heavens. A series of interviews in Marksville, Louisiana illustrate how a number of residents all witnessed a deluge of flying fish. From the testimony of the wonderfully named Sheriff Potch Didier to the accounts of several older woman (who all seem to have had maids at the time - clearly this was an affluent neighbourhood) it all sounds most odd.

Although Arthur considers that the whirlwind theory - freak atmospheric conditions which cause the likes of fish or frogs to be scooped up - might explain some of these events, he concedes that it doesn't answer all of them. And why are there never any reports of fish, frogs or other items getting sucked up into the sky?

Gordon Honeycombe's incredibly detailed narration sets the scene for the next strange event. "On Sunday March the 13th 1977, Mr Alfred Wilson-Osbourne, chess correspondent for the Bristol Evening Post, left the Westbury Park Methodist Church to walk home with his wife. Their journey took them past a car showroom."

And what did they see? A shower of hazelnuts. Mr Wilson-Osbourne wins the prize for the most accurate estimation of the number of objects he saw. Joe Alpin reckoned he saw millions of frogs, Sylvia Mowday estimated that she observed hundreds of frogs, whilst Mr Wilson-Osbourne gives us a more precise figure - three hundred and fifty.

These aren't the most staggering of mysteries, but they've quite fun nonetheless and some of the interviewees are highly entertaining.

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arthur c. clarke's mysterious world - Archive Television Musings

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Out of the Blue opens with Arthur playing table tennis. This seems slightly odd, but all becomes clear when he explains that his daily table-tennis partner - at the Otter's Club, Colombo - saw fish falling from the sky. There's some classic eye-witness interviews in this one.