“HELLO, I’m Claude Shannon, a mathematician here at the Bell Telephone Laboratories,” says the lean man in a suit and tie as the camera zooms in and a jaunty jingle plays. It is 1952 and for engineers and mathematicians, Shannon is already a legend who needs no introduction. To the millions of viewers across the US, he is still unknown – but not for long.
Shannon was in a promotional film to demonstrate Theseus, a wooden mouse with copper whiskers that was about to become a national sensation. Like its mythological namesake, the mouse was an expert at solving labyrinths. After finding its way through a metal-walled maze to a piece of metallic “cheese” by blind trial and error, could recall the path and navigate the maze perfectly on its next try. It could even adapt if the maze’s walls were moved. As Shannon tells the camera, “solving a problem and remembering the solution involves a certain level of mental activity, something akin, perhaps, to a brain”. For the Americans watching, Theseus was astounding: nothing less than a thinking machine.
Shannon had spent evenings with his wife, Betty, building the system. It was inspired, he said, by his love of Erector construction sets and his attempt to solve the hedge maze at Hampton Court Palace in London.
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As well as starring in promotions for Bell Labs, Theseus was covered by the leading magazines of the day, Time, Life and Popular Science, which ran a feature titled, “This mouse is smarter than you are”. Theseus so impressed Shannon’s bosses that they nearly promoted him to the board of directors in a fit of enthusiasm.
By today’s standards – now that artificial intelligence can beat the world’s best chess and Go players, and drive our cars – remembering the location of some “cheese” seems a modest achievement. But at the time, the Theseus system was remarkable. It was also the embodiment of two of Shannon’s foundational contributions to the information age.
The first was to show that electrical circuits could use binary logic. The mouse was propelled by magnets and motors hidden underneath, and its memory was comprised of 75 electromechanical relays concealed in the guts of the maze.
Shannon could build a relay-based memory system because he had spent years exploring the capacity of switches to collectively act as a kind of brain. In 1937, as a graduate student at MIT, he drew on the work of the 19th-century British logician George Boole, who had realised that the standard expressions of logic are founded on just a handful of expressions – for instance, AND, OR, NOT and IF. Shannon showed that switches could perform these functions. This discovery meant that, in theory, enormously complex logical puzzles could be “mechanised” by splitting them into a series of minute steps. All it took was a set of binary devices capable of representing 1/0, on/off – or in the terms of logic, true/false.
The results of this leap in thinking were profound. The idea that circuits can perform logic forms the basis of all computers. Even in 1937, Shannon’s contemporaries understood the importance of what he had discovered: he won awards and a write-up in The New York Times. Later, Harvard University psychologist Howard Gardner would call Shannon’s paper “possibly the most important, and also the most famous, master’s thesis of the century”. He was 21 years old.
That was Shannon’s first great leap of abstraction, but he wasn’t done. His second was also represented in Theseus’s relays. The system storing the mouse’s path was digital. That is, because each switch represented either 1 or 0, the system stored discrete values, rather than the continuous sweep of values found in an analogue setup. In 1948, four years before Theseus’s debut, Shannon showed the power of digital systems to not only perform logic, but also to allow the flawless transmission of information.
“The mouse so impressed his bosses, they nearly promoted him to the board”
In his groundbreaking paper ““, published while at Bell Labs, Shannon introduced the bit (short for “binary digit”), the fundamental measure of information and the bedrock of the information age. Shannon proved that digital codes could represent any kind of message, compressing them and slashing the amount of time and money it would take to send them. And most revolutionary of all, he showed how the right codes could allow us to send digital messages from point A to B with perfect fidelity.
The prestige that Shannon’s work brought him gave him free rein to pursue his passion for gadgeteering. After all, who was going to tell the founder of information theory how to spend his time? So in the years after his breakthrough, his inventions proliferated. They included a flame-throwing trumpet, a juggling robot, a fleet of customised unicycles, a computer that operated in Roman numerals, which he named THROBAC (Thrifty Roman-Numeral Backward-Looking Computer), and the blueprint for a system to help Americans drive on the left-hand side of the road in the UK. This latter design detailed a series of mirrors and a reversal of the car’s steering mechanism to give the driver the impression they were still on the right-hand side of the road. With Ed Thorp, an MIT professor, Shannon developed arguably the first wearable computer: a device for beating the house at roulette, which he and Thorp used to profitable effect in Las Vegas.
Shannon would later dismiss his tinkering as happily useless: “I’ve always pursued my interests without much regard to financial value or value to the world,” he said. “I’ve spent lots of time on totally useless things.” But he was being modest. Even as the contraptions piled up in his home workshop, Shannon kept a foot in emerging fields like AI. For instance, his early chess-playing computer, which could handle a six-piece endgame, is a distant ancestor of IBM’s Deep Blue. His work was always seriously unserious.
More fundamentally, there was simply no divorcing the kind of passionate curiosity that created Theseus and its companion gadgets from the mind that asked how a box of switches could mimic a brain, or how every single message could be broken into bits. Theseus wasn’t just a model of artificial intelligence: it was the embodiment of the very human intelligence that made our digital world possible.
This article appeared in print under the headline “He broke everything into bits”
