Every time we send an e-mail, chat online, talk on the phone, surf the Internet or watch a streaming series, Claude Shannon’s innovation lies behind it. However, after having laid the foundations of digitalisation and all our current communication systems, he disappeared from the scientific limelight. It is only in recent years that his true merits as the creator of “information theory” have been recognised. In addition, this charismatic mathematician, engineer, inventor and juggler deployed his boundless creativity in fields as disparate as digital circuit design, genetics, cryptanalysis and artificial intelligence.
Claude Shannon (30 April 1916 – 24 February 2001) grew up in Gaylord, a small town in the state of Michigan (USA). From an early age, he excelled at mathematics and showed a remarkable penchant for mechanical and electrical objects, specialising in fixing the broken radios in his neighbourhood. As a teenager, he idolised Edison (with whom he had ancestors in common) and built a remote-controlled boat and even a telegraph to communicate using Morse code with his friend Rodney Hutchins, who lived some 800 metres away.
After graduating as an electrical engineer and mathematician from the University of Michigan, he began his research career at MIT, where Vannevar Bush (who envisioned the forerunner of the Internet) eventually became his mentor and one of his greatest professional influences. There he worked on some of the early computers, including the most advanced analogue computer of that era, the differential analyser.
His scientific debut
In his scientific debut—a bachelor’s thesis submitted in 1938 at the age of just 21—he took George Boole’s ideas further, opening the way for the design of digital circuits, with which he showed that any logical-numeric relationship could be represented. This brilliant work attracted much attention in specialist journals of the time and was later described as “one of the most important theses in history,” according to Herman Goldstine in his book The Computer from Pascal to Von Neumann. In 1940, Bush suggested that he develop a mathematical formulation of Mendelian genetics, which Shannon shaped in his doctoral thesis, entitled “An Algebra for Theoretical Genetics“.
After receiving his doctorate at MIT, Shannon continued his research at Princeton, where he worked with John von Neumann and Hermann Weyl and met sporadically with figures such as Albert Einstein and Kurt Gödel. This environment of excellence, unique in history, allowed Shannon to move freely among various disciplines, and this helped him to form the embryo of his “information theory,” whose gestation was interrupted by a force majeure: the outbreak of the Second World War.
The best minds in the USA were immediately recruited by various government agencies and private research centres to work on the country’s defence. He began working at Bell Labs, first on fire-control systems and then on code encryption and telecommunications security. This second assignment led him to meet Alan Turing in person in Washington in early 1943. The two men shared their foundational ideas for modern computing and developed a cordial relationship.
His groundbreaking Theory of Communication
Once the war was over, Claude Shannon finally had a quiet period to consolidate all the knowledge he had acquired during the previous decade in his masterpiece: A Mathematical Theory of Communication. Published when he was just 32 years old, it contains a series of mathematical laws dealing with the measurement and representation of information and governing its transmission and processing, as well as the capacity of the communication systems over which it is transmitted.
In his groundbreaking theory, he also postulated that the ratio between the signal we are trying to send and noise is constant. This rendered obsolete the classical approach to combating noise (repeating the transmission or amplifying the signal sent). Shannon assumed that noise is inevitable in any communication channel and proposed a revolutionary way to combat it: adding redundancy to the encoded message. In this way, despite any distortion or interference affecting the signal, errors can always be corrected at the destination and the original information reliably recovered.
The ideas described in his article lay the foundations for most of today’s communication systems, including their error correction and compression mechanisms. Shannon also introduced the concept of information entropy and popularised the term bit (binary digit, coined by John Tukey), being the first to propose that all information—whether written language, spoken language, images or video—could be digitised, i.e. converted into bits.
Computational chess and Theseus
In the following years, he made important contributions to the field of artificial intelligence. At a time when computers were gigantic machines with limited computing power, he predicted that they could be programmed to play chess and eventually defeat a human. In his 1950 essay, which paved the way for computational chess, he estimated that the number of possible games, also known as Shannon’s Number, would be 10120, a figure greater than the number of atoms in the known universe. Shannon therefore considered that using a brute-force algorithm would not be efficient at all. Instead, he suggested an algorithm with a certain strategic artificial intelligence; only the best moves of each position should be analysed, more or less as human players do.
A year later, in 1951, Shannon surprised everyone again with the creation of Theseus, a mechanical mouse capable of solving a maze and finding a piece of cheese by itself. Theseus’ “brain,” located beneath the maze, was made up of a complex system of magnets and relays and was largely assembled by Betty Shannon, his wife. Always a close collaborator, Betty was a great encouragement and help in developing his ideas.
Claude Shannon was by then a star, or at least as much of a star as a scientist can be. In 1954, Fortune magazine featured him on a list of the 20 most important scientists in the USA, alongside future Nobel Laureates such as Richard Feynman and James Watson. Behind the persona of the mathematician who had revolutionised telecommunications, there was also a great juggler, musician, code breaker, stock market expert, poet and born innovator. This charisma and brilliance also led to television appearances on national networks, and to a shift from research journals to general publications such as Time and Life; even Vogue magazine devoted an extensive article¡to Shannon in which he was profiled by the prestigious photographer Henri Cartier-Bresson.
An unbridled creativity and imagination
At the height of his career, after a 15-year stint at Bell Labs, Shannon returned to MIT in 1956 as a professor. During his time there, he broke away from the main academic lines of research and continued to give free rein to his unbridled creativity and imagination, applying it mainly to his hobbies and interests. Shannon devoted those years to building a large number of home-made devices: a flame-throwing trumpet, a rocket-powered Frisbee and a robot capable of juggling three balls.
With the dawning of the digital age, which his ideas had helped launch, Claude Shannon was gradually forgotten, though not entirely. In 1985, now retired, he received the first edition of the Kyoto Prize for Mathematics, Japan’s highest award for the arts and sciences, which has since gained considerable prestige and covers areas not eligible for a Nobel Prize.
Suffering from Alzheimer’s disease, Shannon died in February 2001 as a relatively anonymous figure. On the occasion of the centenary of his birth, in 2016 a number of tributes were paid to him. In 2017, his biography—A Mind at Play—was published, and in 2018, the Institute of Electrical and Electronics Engineers (IEEE) produced a documentary entitled “The bit player”. All these initiatives highlighted the hyper-creative nature of one of the great drivers of the digital revolution that has changed our world. In the final years of his life, Shannon was able to witness this, away from the media spotlight by his own choice but always dedicated to following his infinite curiosity.