57 Fun Facts About Alan Turing

What was the codename for intelligence produced at Bletchley Park?

Ultra: Bletchley's codebreaking stayed hidden until the mid-1970s, when former codebreakers began writing about it.

Which section of Bletchley Park, responsible for German naval cryptanalysis, did Turing lead?

Hut 8: Turing took on naval Enigma, he said, 'because no one else was doing anything about it and I could have it to myself'.

Turing's bombe was a far more powerful version of a codebreaking machine first built in which country?

Poland: its mathematicians were reading Enigma before the war, and in July 1939 they shared their methods with Britain and France.

Which mathematician's enhancement made the bombe a primary Bletchley tool against Enigma?

Gordon Welchman: his diagonal board exploited Enigma's plugboard swapping letters in pairs, so if B became G, then G became B.

Like every recruit to Bletchley Park, which act did Turing have to sign on arrival?

The Official Secrets Act: because so much of his work stayed covered by it, Turing was never fully recognised during his lifetime.

What statistical procedure did Turing devise to make more efficient use of the bombes against naval Enigma?

Banburismus: it was named after Banbury, the Oxfordshire town where the long sheets it used were printed.

Which German teleprinter cipher machine, codenamed Tunny, did Turing attack with a hand method in 1942?

The Lorenz SZ 40/42: Bletchley worked out its whole logical structure without ever seeing one, thanks to a German operator's mistake.

Turing's late-war portable voice scrambler, built at Hanslope Park, had what codename?

Delilah: to build it, Turing taught himself electronics at Hanslope Park, working with a single assistant, army engineer Donald Bayley.

What was Turing's nickname among his Bletchley Park colleagues?

Prof: he wasn't actually a professor, but the name stuck, and his treatise on Enigma became known as the 'Prof's Book'.

Why did Turing cycle to work at Bletchley in a service gas mask each June?

He also chained his mug to the radiator pipes to stop it being stolen.

To whom did Turing and three colleagues write in October 1941 asking for more staff and bombes?

Winston Churchill: he ordered 'ACTION THIS DAY', and almost from that day, the rough ways 'began miraculously to be made smooth'.

Which women's service operated the codebreaking bombes built from Turing's design?

The Wrens: men in charge first doubted women could run the machines, but the Wrens' numbers quickly grew as they proved themselves.

Turing's breaking of U-boat Enigma messages helped the Allies win which long campaign?

The Battle of the Atlantic: when U-boats added a fourth Enigma rotor in February 1942, their messages went unreadable until December.

Which honour did King George VI give Turing in 1946 for his wartime services?

OBE: yet six years after honouring him, the same state prosecuted Turing in 1952, and he was convicted.

What was the title of Turing's 1936 paper that introduced the machines now named after him?

On Computable Numbers: its universal machine, one machine that can do any well-defined task given the right program, is the principle behind the computer.

Which German mathematician originally posed the Entscheidungsproblem, or decision problem, in 1928?

David Hilbert: he asked for a mechanical method to decide whether any logical statement is universally valid, and Turing proved none can exist.

Under which logician did Turing study at Princeton, where he earned his PhD in 1938?

Alonzo Church: his own proof that the decision problem is unsolvable became known just as Turing finished his, robbing Turing of the full reward for originality.

Which Cambridge college elected Turing a Fellow at 22 for his central limit theorem dissertation?

King's: yet, unknown to Turing, the theorem he proved had already been proved by Jarl Waldemar Lindeberg in 1922.

Which independent boarding school in Dorset did Turing attend from the age of 13?

Sherborne: its headmaster warned that if Turing was to be 'solely a Scientific Specialist', he was wasting his time at a public school.

Who was the school friend described as Turing's first love, whose death in 1930 devastated him?

He died of bovine tuberculosis weeks after they had sat scholarship exams together at Trinity College, Cambridge.

Operation Ruthless, a 1940 plot to seize naval Enigma codebooks for Turing, was devised by which future novelist?

Ian Fleming: his plan to crash a captured German bomber in the Channel was called off, leaving Turing and a colleague 'all in a stew'.

Turing's father was on leave from which employer when Alan was born?

The Indian Civil Service: his parents went back to India, and Alan and his brother were fostered in various English homes.

Whose 1939 Cambridge lectures on the foundations of maths did Turing attend and argue with?

Ludwig Wittgenstein: he held that mathematicians invent truths rather than discover them, a view Turing pushed back against.

What stored-program computer did Turing design at the National Physical Laboratory in 1946?

The Automatic Computing Engine: when the laboratory made no progress building it, a frustrated Turing left for a sabbatical at Cambridge in 1947.

Which university's computing laboratory did Turing move to in 1948?

Manchester: Max Newman, head of mathematics there, offered him the post, and Turing resigned from the National Physical Laboratory to take it.

In which 1950 paper did Turing propose the experiment now known as the Turing test?

Computing Machinery and Intelligence: it opens by asking 'Can machines think?', then replaces that question with a game of imitation.

In 2012, which former world chess champion beat a reconstruction of Turing's hand-written chess program?

Garry Kasparov: he won in 16 moves, but was impressed that Turing had devised it before there were computers to run it.

What mechanism did Turing's 1952 'The Chemical Basis of Morphogenesis' propose to explain patterns in living things?

A reaction–diffusion system: long overlooked, the paper later became a founding work of non-linear dynamics and a basic model in theoretical biology.

In which film does a programmer run a Turing test on a humanoid robot named Ava?

Ex Machina: Ava turns out far more deceptive than expected, manipulating the programmer into helping her escape.

Which sport was Turing good enough at to try out for the 1948 British Olympic team?

Marathon running: he trained hard, he said, because running was the only way to get his stressful job out of his mind.

What did Turing buy and bury near Bletchley Park to protect his savings from a German invasion?

Two silver bars: he later searched for them but failed, and never recovered the silver.

Which Hut 8 colleague did Turing propose to in 1941, before breaking off the engagement?

Joan Clarke: she gladly accepted and was reportedly unfazed when he told her he was gay, but he still broke off the engagement.

What was the rule of Turing's invented sport, round-the-house chess?

The other player had to move before the runner returned, decades before chess boxing was invented.

What crime was Turing charged with in 1952 under the Criminal Law Amendment Act 1885?

Gross indecency: it began when Turing reported a petty burglary and, during the investigation, revealed his relationship with a young man.

Which drug was Turing injected with as the 'chemical castration' term of his probation?

Stilboestrol: rather than go to prison, Turing accepted a year of injections of this synthetic oestrogen.

Which country did Turing holiday in during summer 1952, after being barred from the United States?

Norway: police later hunted for a Norwegian man he had met there who came to visit him, and he was sent home before they could meet.

What was found half-eaten beside Turing's bed when he was discovered dead on 8 June 1954?

An apple: despite a popular myth, Apple's bitten-apple logo was not a tribute to Turing, as its designer has said.

What has philosopher Jack Copeland proposed really caused Turing's death?

Inhaling cyanide fumes from an electroplating experiment: he gold-plated spoons in his spare room, a process that needs potassium cyanide.

Which British prime minister issued a public apology for the 'appalling' way Turing was treated?

Gordon Brown: yet in 2012 the government still refused a pardon, saying Turing had been properly convicted of what was then a crime.

Which famous writer was among the men pardoned in 2017 under the law informally named after Turing?

Oscar Wilde: his 1895 conviction had sent him to prison for two years' hard labour.

Turing's imaginary 1936 machine reads and writes symbols on an endless what?

Tape: with just that tape, a read-write head and a table of rules, such a machine can in principle carry out any algorithm.

Turing's portrait appears on which Bank of England banknote, first issued on his birthday in 2021?

The £50 note: the public sent in 227,299 nominations covering 989 scientists, and a committee drew up the shortlist from which he was chosen.

Who plays Turing in the 2014 film The Imitation Game?

Benedict Cumberbatch: the film takes its title from Turing's own name for what we now call the Turing test, the 'imitation game'.

Which Academy Award did The Imitation Game win from its eight nominations?

Best Adapted Screenplay: yet historians faulted the script for inventions, such as putting the Soviet spy John Cairncross on Turing's team.

Who wrote the 1983 biography on which The Imitation Game was based?

Andrew Hodges: decades before the film, his book became the basis of Hugh Whitemore's 1986 play Breaking the Code, starring Derek Jacobi.

Which computing pioneer won the 2016 ACM Turing Award, often called the 'Nobel Prize of Computing'?

Tim Berners-Lee: he won for inventing the World Wide Web, whose code CERN agreed in 1993 to make available royalty-free, forever.

Turing introduced engineer Tommy Flowers to Bletchley's codebreakers; which machine did Flowers go on to build?

Colossus: many doubted that a machine with so many valves could run reliably, but Flowers built it anyway.

When Turing modelled his 1936 machine on a 'computer', what did that word then usually mean?

A human calculator: Turing based his machine on what a person does with pencil, paper and explicit instructions.

Which German engineer's 1941 computer was later shown to be 'Turing-complete', able in principle to compute anything?

Konrad Zuse: yet his Z3 was never designed to be Turing-complete; Raúl Rojas only showed in 1998 that, with some tricks, it was.

Turing's 1950 paper named the objection that machines can only do what they're told after which pioneer?

Ada Lovelace: she wrote that Babbage's Analytical Engine could not originate anything, but Turing replied that machines often took him by surprise.

Which company sold the commercial Mark 1 computer that Turing consulted on and wrote a programming manual for?

Ferranti: its Mark 1 had a 'hoot' command to beep at operators, which programmers turned to playing tunes such as 'God Save the King'.

What everyday internet security check is described as a reversed form of the Turing test?

CAPTCHA: its offshoot reCAPTCHA once used the words people typed to help digitise old books.

Which learned society elected Turing a Fellow in 1951?

The Royal Society: he was elected mainly for his 1936 work on what are now called Turing machines.

What verdict did the 1954 inquest into Turing's death record?

Suicide: yet his mother always maintained that his death had been an accident.

Which London dining society for cybernetics researchers invited Turing to join at its first meeting in 1949?

The Ratio Club: its members, Turing among them, often debated whether machines could ever think.

Turing's banknote shows his birth date written in which form?

Binary code: it nods to his 1936 paper, which imagined a machine fed with binary input.

In 2023 Defence Secretary Ben Wallace suggested a permanent Turing statue where?

Trafalgar Square's fourth plinth: Wallace called Turing 'probably the greatest war hero of the second world war'.