Technical Article

Alan Turing: The Innovation Behind Modern Computer Controls

January 09, 2023 by Stephanie Leonida

Nearly all modern programmable control systems are constructed from computer-driven algorithms. Join us to explore the extraordinary life of the ‘founder of computing science’, Alan Turing.

This article focuses on the life of one extraordinary man⁠—dealt a terrible hand by the evolving progress of modern society, despite contributing to its advancement—known across the globe as Alan Mathias Turing.


Alan Turing at age sixteen

Alan Turing, age 16. Image used courtesy of WikiMedia


Alan Turing Early Life

The British logician and mathematician, Alan Turing, was born in Maida Vale, London (June 23, 1912) to Julius Mathius Turing, a British member of the Indian Civil Service, and Ethel Sara Turing, daughter of Edward Waller Stoney, a chief engineer of the Madras and Southern Mahratta Railways. 

Turing was a fiercely determined knowledge-seeker, so much so that he rode his bicycle 60 miles from Southampton to Sherborne School because of a national strike to attend the first day of term. He rode unaccompanied and stayed in an inn overnight. At the private boarding school, Turing made a not-so-favorable reputation for himself through his proclivity for mathematics and science in a classics-focused school. 

In written correspondence to Turing’s parents, his headmaster wrote: “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.”


The Genesis of Turing’s Legacy

Turing embarked on a daring search with an insatiable desire to know the workings of the human mind and see it manifested through an entirely different medium of code and symbols. 

Since his days at Sherborne, Turing went on to study mathematics at the University of Cambridge, entering in 1931 and graduating in 1934. Following his graduation, Turing was granted a fellowship at King’s College in recognition of his research in an area of mathematics called probability theory

In 1936, Turing (aged 24) published a foundational piece of work entitled: “On Computable Numbers, with an Application to the Entscheidungsproblem [Decision Problem]”. At the same time, his colleague, American mathematical logician Alonzo Church, reached the same conclusion, published in Turing’s work but used different methods to reach it.

An integral part of Turing’s argument concerning the Decision Problem is what is now known as the Church-Turing thesis, which is said to serve as the basis for computer science as we know it today. The thesis claims that ‘Turing machines’—a term coined by Church in his review of Turing’s work—can also solve and compute everything that humans can solve. 

Turing machines, or “automatic machines”—as Turing termed them back in 1936, are theoretical machines that Turing imagined as having an infinitely long amount of tape divided into cells containing either a 0, 1, or empty space. Depending on a set of predetermined instructions, the machines could read and change the numbers in the cells, as well as move the position of the cells. This read-write machine essentially stored a program, which can be defined as a set of detailed coded instructions/rules that inform a computer’s operation. A program can use code to express an algorithm or a detailed set of steps for carrying out a particular process to solve a problem.


Turing machines explained. Video used courtesy of  Isaac Computer Science 


Turing’s mathematical model of computation allowed Turing to determine that some mathematical problems cannot be figured out by using a single algorithm. Turing soon developed the idea of a Universal Turing machine that could take on any computable problem.

In his review, Church acknowledged the superiority of Turing’s work over his own, expressing that the idea of computability through a Turing machine “has the advantage of making the identification with effectiveness…evident immediately.”

From 1936 to 1938, Turing studied mathematical logic for his PhD under Church at Princeton University. 


The Enigma Machine

Following Turing’s academic achievements, he joined Gordon Welchman at the British Government Code and Cypher School (GC&CS) at Bletchley Park as a codebreaker during the second world war. Turing oversaw and led efforts concerned with updating the Polish-born cryptologic bomb (or Bomba) used for decrypting ciphers from the German Enigma machine.

Alan Turing's enigma machine

The Enigma machine. Image used courtesy of the lenscap50 -


Eventually, the Turing-Welchman machine, Bombe, was created in 1939. The Bombe was built by the British Tabulating Company (BTM, which later became ICL) at Letchworth (UK). More than 200 of these machines were built to spread the chances of their survival should a bombing occur. The very first Bombe was named Victory and later modified with the addition of a diagonal board, invented by Welchman. The board helped reduce the number of steps required for codebreaking. 

With the combined effort from both Polish and British codebreakers, transmissions concerning important German military operations could be intercepted. As German U-boats were planned for deployment to eradicate vital convoys of allied supplies, the British were able to determine these plans and adapt to change the course of the war in their favor.


An Unsung Hero No Longer

Following the war, Turing developed the Automatic Computing Engine (ACE), although it was not physically constructed. Turing believed that the ACE had unbridled potential in forwarding progress toward artificial intelligence (AI)-based systems.

Turing bought a house in Wilmslow in 1950, close to the University of Manchester’s computing laboratory where he continued his work.

Despite the monumental feet of Turing and his fellow code-breakers at Bletchley in preventing the further loss of lives that the war would have surely determined, he was treated horrifically by British society.


memorial statue of Alan Turing, Sackville Gardens, Manchester

A memorial statue of Alan Turing, Sackville Gardens, Manchester. Image used courtesy of Robertvt -


Turing and Arnold Murray were charged with “gross indecency”, with both men pleading guilty in court. While Murray received a conditional discharge, Turing was given the choice of going to jail or receiving hormone treatment—also known as chemical castration—to reduce his sex drive. This would have been utterly debilitating for Turing.

He died in 1954 at his home in Wilmslow from cyanide poisoning with a half-eaten apple found at his bedside table. Whether Alan Turing’s death was a suicide as some suspect, or rather an accident, cannot be confirmed.

A petition brought forward by John-Graham Cummin in 2009 was acknowledged by Prime Minister Gordon Brown. He apologized to Alan Turing on behalf of the British Government for being treated appallingly.

Under ‘Turing’s Law’, Alan Turing received a Royal Pardon, signed by Queen Elizabeth II in 2013. Only in 2017 was the law refreshed after the Policing and Crime Bill today received Royal Assent, allowing for others committed as Turing was to be pardoned. 


Alan Turing, Father of AI

Turing’s work in computer science and artificial intelligence is foundational for nearly all modern programmable control systems. Whether it’s enabling robots to perform complex tasks or the efficience brought about by automated machinery, Turing’s work has significantly impacted the broad field of industrial automation.