The life of Alan Turing.

An article by Alex Blanchard (Outreach Officer)

Content Warning: Homophobia, suicide.

Hi everyone! For LGBT History Month, SCOPE will be celebrating historical LGBT scientists and engineers, and showcasing relevant charities.

After twice trending on Twitter in the past month, we are going to start with Alan Turing. Alan Mathison Turing, OBE, was born in Maida Vale, London on the 23rd of June 1912. He studied at King’s College, Cambridge graduating with a 1st in Mathematics in 1934. The following year, Turing was inducted there as a Fellow following his work on the central limit theorem.

In 1936, Turing published the paper “On Computable Numbers, with an Application to the Entscheidungsproblem”, where a hypothetical machine called a Turing Machine was created that could solve all computable problems when expressed by an algorithm. The paper aimed to discover whether a given arithmetic statement could be proven to be true or false by an algorithm, concluding that it is impossible to do so. This work was done independently with Alonzo Church, who came to the same conclusion. Turing eventually studied under Church at Princeton University; he received his PhD there in 1938, and soon after returned to the UK.

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Alan Turing Source:

Shortly after his return, Turing started working with the British codebreaking organisation, the Government Code and Cyber School. The task was to crack the Enigma machine, which he managed to systematically break in 1942. From this, it was possible to break any given cypher that the Enigma used and was able to break almost 3000 ciphered messages every day. This work was instrumental in capturing wartime intelligence and lead to an Allied victory in World War 2. Turing was later awarded the OBE for his efforts.

After World War 2, Turing turned to working on computers, working for the National Physical Laboratory, and later Manchester University. During this time, he designed a machine that could store programs in its memory, which had not been possible beforehand. This was brought to life at Manchester, the Manchester Mark 1, which was operational by 1949, running overnight without issue. Afterwards, Turing proved himself a keen programmer, eventually making an algorithm for a computer to play chess, which reportedly played “a recognisable game of chess”.

In March 1952, Turing was convicted of “Gross Indecency”, or homosexuality, after being found in a relationship with Arnold Murray. Murray was not Turing’s first lover, having been previously in a relationship during his secondary school days with Christopher Morcom, a fellow pupil. Upon Morcom’s death in 1930, Turing kept in touch with Frances Morcom, Christopher’s mother, with the two corresponding regularly for years afterwards. As punishment for his crime and pleading guilty, Turing had the choice of jail or a year of hormonal therapy, essentially neutering himself. Turing, now despondent about his criminal record which stopped him from returning to working for the government, chose the latter. The treatment was reported to reduce Turing’s libido and grow breast tissue after being injected with a synthetic oestrogen.

On the 7th of June 1954, Turing was found dead after cyanide poisoning; it was ruled by an inquest to be suicide, but this has been debated, most vocally by Jack Copeland. Leading up to his death, Turing had been in good spirits and had kept various laboratory chemicals in his house, including cyanide, for which careless handling could have been behind his death.

After his death, he has been revered as one of the greatest Britons, and one of the most important people of the 20th Century. In 2013, Queen Elizabeth II posthumously granted Turing a rare royal pardon, 60 years after his death. In 2016, “Turing’s Law” was ratified in British Law, posthumously pardoning every man who had been convicted with homosexuality. The device on which you are reading this post would unlikely be possible without Turing’s work.

If you would like to donate to a charity, the Alan Turing Trust has been set up in his name by his family, to use technology to empower disadvantaged communities, done by donating computers and educational software to those in need. To find out more and to donate, please visit

That is all for this week, next week, we will be looking at a pioneer for women’s education, and the first practising woman doctor in Scotland.

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