1948: Information Theory

Photo: Claude Shannon with electrical mouse and maze. In 1948, C.E. Shannon published an article titled "The Mathematical Theory of Communication," which quickly became known as Information Theory. IT made it possible to determine the theoretical limit of any channel's information-carrying capacity. Using IT as a mathematical benchmark, engineers were finally able to provide efficient, error-free transmission over noisy channels. IT also made possible the development of digital systems, which handle information ? voice, data video ? in streams of coded pulses. Without Information Theory, the Web would not exist.

Four years after he published his ground-breaking theory, Shannon invented an electrical mouse with a telephone relay switch brain. Its ability to find its way through a maze demonstrated that computers could learn, a startling revelation to those who, until then, had used them only as giant adding machines.