July 2001

Claude Shannon: Reluctant Father of the Digital Age

A juggling unicyclist transformed "information" from a vague idea into a precise concept that underlies the digital revolution.

By M. Mitchell Waldrop

Pick up a favorite CD. Now drop it on the floor. Smear it with your fingerprints. Then slide it into the slot on the player-and listen as the music comes out just as crystal clear as the day you first opened the plastic case. Before moving on with the rest of your day, give a moment of thought to the man whose revolutionary ideas made this miracle possible: Claude Elwood Shannon.

Shannon, who died in February after a long illness, was one of the greatest of the giants who created the information age. John von Neumann, Alan Turing and many other visionaries gave us computers that could process information. But it was Claude Shannon who gave us the modern concept of information-an intellectual leap that earns him a place on whatever high-tech equivalent of Mount Rushmore is one day established.

The entire science of information theory grew out of one electrifying paper that Shannon published in 1948, when he was a 32-year-old researcher at Bell Laboratories. Shannon showed how the once-vague notion of information could be defined and quantified with absolute precision. He demonstrated the essential unity of all information media, pointing out that text, telephone signals, radio waves, pictures, film and every other mode of communication could be encoded in the universal language of binary digits, or bits-a term that his article was the first to use in print. Shannon laid forth the idea that once information became digital, it could be transmitted without error. This was a breathtaking conceptual leap that led directly to such familiar and robust objects as CDs. Shannon had written "a blueprint for the digital age," says MIT information theorist Robert Gallager, who is still awed by the 1948 paper.

And that's not even counting the master's dissertation Shannon had written 10 years earlier-the one where he articulated the principles behind all modern computers. "Claude did so much in enabling modern technology that it's hard to know where to start and end," says Gallager, who worked with Shannon in the 1960s. "He had this amazing clarity of vision. Einstein had it, too-this ability to take on a complicated problem and find the right way to look at it, so that things become very simple."