What do you think of when you imagine the man who dreamed up the first digital computer? Does a white lab coat come to mind, someone with glasses and crazy hair who tinkers with wires and looks half-mad with delight? Or maybe you think of someone quiet but reserved. A man who is awkward and enjoys working alone but is also funny and good-looking. A man who thinks outside the box and is not afraid to speak his mind, even to people in power.

If you imagined the second, then you just imagined Alan Turing, the founder of modern computing.

Young Alan

Alan Turing was born to a life of privilege on June 23, 1912. Growing up in London, Alan had it all—maids, cooks, caregivers, and fancy vacations. His mother was highly educated, and his father had a position in the Indian Civil Service, which meant Alan’s parents were away more often than not. All the privilege in the world would not make up for the fact that Alan grew up alone—in a big house full of adults who were paid to watch over him.

Once, he wrote to his mother using a fountain pen he created himself. He even included the design in the letter. Another time, he fashioned his own typewriter.

Alan entered boarding school at age nine and found his passion for mathematics a few years later. One of his teachers recalled how Alan was “difficult to teach, as he preferred his own independent methods” of learning that were “sometimes clumsy and cumbersome and sometimes brilliant but unsound.”

A Promising Future

In the autumn of 1931, Alan became a student of King’s College, Cambridge, where he found himself feeling at home, maybe for the first time ever. At the school, Alan enjoyed going to the opera and theater with friends, playing tennis, rowing, and playing cards. Unlike his time in boarding school, Alan excelled in all subjects, especially mathematics. At graduation, he received the highest grade of “B Star Wrangler,” which was a mark of high distinction.

Two years later, at the age of 22, Alan was elected as a fellow at King’s College. It was during this time that Alan’s first article was published in the August journal of Proceedings of the London Mathematical Society. Over the course of several weeks, Alan worked on a particularly difficult problem within the realm of mathematics and came up with an idea about an amazing machine. He wrote up his idea and published another article in 1936. Today, that article is considered the foundation of modern computer science.

Alan became an overnight sensation, and he quickly received an offer from Princeton University in the United States, where he earned his Ph.D. in 18 months (it usually took three years).

But the world was quickly changing.
With war in Europe looming closer, Alan returned to his fellowship at King’s in 1938, eager to continue his work.

Bletchley Park

Early at the start of World War II, the Allied forces realized they had a big problem. The German Nazis had a code system, the Enigma, that was so advanced, it was nearly impossible to decipher. German U-boats, or submarines, were sending their codes at such an alarming speed that the Allies hardly had time to warn their ships before an attack. An early code-breaking machine known as the “Bombe” was already in use; however, the Germans kept improving their Enigma machine, making it difficult for the Allies to crack the code.

That's where Alan came in. 

Fifty miles outside of London, in a country mansion, a secret group of codebreakers went to work each day to find a more efficient way to crack the German’s Enigma machine. Alan began working at Bletchley Park in 1939, the day after the United Kingdom declared war on Germany. Alan knew he had a difficult task to perform in his new top secret role. The Enigma machine changed its code settings every 24 hours, which meant there were 159 quintillion possible combinations the codebreakers had to decipher by hand—each day!  

Alan knew he could create a machine that could crack the code, so together with Gordon Welchman, the men got to work.

The men got to work on their code-breaking machine.
In September 1940, the first Bombe, lovingly nicknamed Agnes, was operational. Finally, the Allies could break the Enigma code in time to prevent disaster!

The Wrens at Bletchley Park quickly began constructing more machines, and soon there were over 211 in use, cracking the Nazis’ codes every day. The Bombe was a huge turning point for WWII and aided the Allies in land, sea, and air victories across Europe.

Alan’s machine was so effective that for many years, the Germans were unaware their “unbreakable” Enigma machine’s code had been cracked. 

The First Computer

Another problem plagued the codebreakers at Bletchley Park: “Tunny” messages. These were electronic messages that broke down letters into a code (ex: the Letter A would be written as 11000 and the letter B as 10011). The Tunny machine would then add other numbers, making the code look like a bunch of random numbers thrown together.

Alan played a big role in deciphering the Tunny code, but this was all done by hand and was different from the Enigma code, so the Bombe couldn’t be used.  

While the United States claimed to have built the first electronic computing machine in 1945, scientists believe Colossus to be the first true computer. While still working at Bletchley Park, Alan began drawing detailed plans for a stored-program electronic computer.

On 48 pages, with 52 diagrams and tables, Alan created the first design for an electronic stored digital computer.

Man or Machine?

By 1949, Alan began working at the University of Manchester as the Deputy Director of the Computing Company and began wondering about artificial intelligence. The idea plagued him, and by 1950, he wrote a paper outlining a method to determine if a machine was intelligent. In the paper, he called this method “the imitation game,” because it proposed an idea of a person interviewing a computer and a human and seeing if the person interviewing could determine which answers were machine-made or human. This later became known as the Turing Test.

Alan Turing believed in the idea of a robot learning from its surroundings and being able to communicate like a human.  

In 1947, Alan gave the first public lecture on artificial intelligence, saying, “what we want is a machine that can learn from experience.”
Today, 78 years later, Alan Turing’s ideas are becoming a reality. Alan paved the way for modern computers, computer software, and artificial intelligence. He was a leading figure in WWII and was a true genius of his day. Today, his legacy lives on as a true pioneer of the information age.