Alan Turing

The Father of Computer Science

Alan Mathison Turing was one of the most profound, imaginative, and impactful thinkers in human history. He is widely known for his revolutionary work in cryptography, saving millions of lives in WWII, and his invention of theoretical computer science, as well as his late work on artificial life.

In 1936, one year after completing his dissertation at King’s College, Cambridge, Turing published the paper “On Computable Numbers, with an Application to the Entscheidungsproblem” that solved a deep problem in number theory by inventing the machine known as the Turing machine, and proving that such machine would be able to perform any computation that could be described in steps. Turing also proved that no algorithm can determine whether a computation will finish and deliver a result. This machine became the basis for modern digital computing.

Passport photo of Alan Turing at age 16

During World War II, Alan Turing worked for the British government at Bletchley Park, a top-secret facility devoted to breaking German codes. Here, he developed several methods to accelerate the decryption of German ciphers. These included enhancements to the pre-war Polish “bomba,” an electromechanical device capable of identifying configurations for the Enigma machine, which was used by the German military to encrypt their communications. Turing’s contributions were critical in deciphering intercepted encoded messages, leading to Allied victories in pivotal battles, such as the Battle of the Atlantic. The work done at Bletchley Park is credited with shortening the war by several years and saving millions of lives.

Although Turing’s contributions to the war effort were crucial, his work remained classified for many years. Only in the 1970s was his involvement at Bletchley Park declassified, and his significant contributions to cryptography were eventually acknowledged.

Statue of Turing holding an Enigma machine. Created by Stephen Kettle, commissioned by the American billionaire Sidney Frank, built from half a million pieces of Welsh slate. Bletchley Park, UK.

After World War II, Alan Turing turned his attention to designing a new type of computer called the “Automatic Computing Engine” (ACE). The ACE was intended to be built at a national laboratory but was delayed due to various bureaucratic and technical issues. Turing became disillusioned with the project and returned to Cambridge, while Victoria University in Manchester built a machine based on Turing’s principles called the Manchester Mark I.

Turing then moved to Manchester to work on software for the Manchester Mark I. It was there that he wrote the paper “Computing Machinery and Intelligence,” in which he examined the issue of artificial intelligence and presented an experiment now known as the Turing test. The goal of the test was to establish a benchmark for identifying a machine as “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.

Pilot Automatic Computing Engine (ACE). The Science Museum, London, UK. Photo by Antoine Taveneaux.

When Turing was in his late thirties, he turned to mathematical biology. He was interested in morphogenesis (how living things develop their shapes and patterns). In 1952, he published his masterpiece “The Chemical Basis of Morphogenesis” that explained his theory. He believed that different chemicals could interact with each other and spread out to create shapes and patterns we see in living things.

At the time, nobody knew about DNA yet, so Turing was way ahead of his time. But even today, his work is still important and is considered one of the classic pieces of work in the field of mathematical biology.

Unfortunately, Turing’s life was not without tragedy. In 1952, he was convicted of homosexuality and chose to undergo chemical castration rather than go to prison. On June 8, 1954, Turing was found dead from cyanide poisoning. An inquest determined his death as a suicide, but it has been noted that the known evidence is also consistent with accidental poisoning.

Following a public campaign in 2009, British prime minister Gordon Brown made an official public apology on behalf of the British government for “the appalling way [Turing] was treated.” Queen Elizabeth II granted a posthumous pardon in 2013.

Today, Turing’s legacy continues to inspire researchers in the fields of computer science, mathematics, and philosophy, and he is recognized as one of the most important figures in the development of modern technology. The Alan Turing Award, often referred to as the “Nobel Prize of Computing,” is considered one of the most prestigious awards in the field of computer science. It is awarded annually by the Association for Computing Machinery (ACM) for contributions of lasting and major technical importance to the computing field.


“Those who can imagine anything, can create the impossible.” —Alan Turing

“A man provided with paper, pencil, and rubber, and subject to strict discipline, is in effect a universal machine.” —Alan Turing

“We can only see a short distance ahead, but we can see plenty there that needs to be done.” —Alan Turing

“Sometimes it is the people who no one imagines anything of who do the things that no one can imagine.” —Alan Turing

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