A mind at play

Turing's was a shadowy figure until Alan Turing The Enigma appeared. A mind at play will likely do the same for Shannon.

Shannon of course is the father of Information Theory,  his insights forming the bedrock of digital communication. As the authors put it, 'information existed before Shannon, just as inertia existed before Newton'. It was Shannon who created the conceptual foundations needed to deal with information in a precise, quantitative manner. First of all, he clarified what information is. Information is what reduces uncertainty, one bit of it exists when we are choosing from two equally likely outcomes. Then he showed that all communication is expressible in terms of bits. Next, each communication channel has an upper limit on how many bits it can carry per second (dependent on the bandwidth and the signal-to-noise ratio). Within this limit, noise can always be defeated; a message can always be sent with an arbitrarily small amount of error. And lastly, all of the above stays true irrespective of whether the message has meaning or not.

The importance of his work was immediately recognized, propelling Shannon to scientific celebrity at 32, but Shannon chose not to pursue it. Information theory quickly became a buzzword in fields ranging from psychology to economics, but it was Shannon who cautioned against blindly jumping on the bandwagon. He returned to his work and spent the rest of his days inventing.

A mechanical mouse that could solve a maze and remember the solution (A concrete demonstration of AI when all the field had was theory). A juggling robot (Shannon was an accomplished juggler, and wrote one of the first papers on mathematics of juggling). A wearable computer to time roulette wheels and a system to place bets to maximize winning (I make my money on the Stock market, not by proving theorems, Shannon once said). A chess playing computer (and a paper establishing the foundations of the field). All sorts of customized unicycles. And the ultimate machine: when switched on, a mechanical arm came out of the box and turned itself off.

Shannon's was a fascinating life, and the book does a good job of bringing it out of the shadows. At a few places it feels a bit sketchy, but that does not take from it's readbility. The authors are clearly in awe of Shannon, and after reading it, you will be too.