I recently had lunch with Erik Davis, whose riffs and insights on the intersection of technology, mysticism, and high weirdness have always inspired me. We talked about one of my favorite head trips, the idea that we're living in a simulation or control system of some kind. Decades before The Matrix, folks like Jacques Vallee, John Keel, Stephen Wolfram, Rudy Rucker, and Hans Moravec explored this notion. And of course it's also been the subject of countless science fiction novels. Recently, Oxford philosopher Nick Bostrom developed a mathematical argument to support the mind-bending theory. But Erik turned me on to Ed Fredkin, a computer scientist whose name I knew but had somehow missed in the context of the Simulation Argument. A pioneer of "digital physics," Fredkin worked with Richard Feynman, made a ton of money in various tech businesses, and is currently a professor at Carnegie Mellon University and MIT. He is also convinced that the universe is a computer. Robert Wright's 1988 book Three Scientists And Their Gods includes a profile of Fredkin. When the book came out, the section on Fredkin was excerpted in The Atlantic. The piece really gives me a sense of the scientist and also does a great job explaining his theories in simple terms. From The Atlantic:
Fredkin works in a twilight zone of modern science–the interface of computer science and physics. Here two concepts that traditionally have ranked among science's most fundamental–matter and energy–keep bumping into a third: information. The exact relationship among the three is a question without a clear answer, a question vague enough, and basic enough, to have inspired a wide variety of opinions. Some scientists have settled for modest and sober answers. Information, they will tell you, is just one of many forms of matter and energy; it is embodied in things like a computer's electrons and a brain's neural firings, things like newsprint and radio waves, and that is that. Others talk in grander terms, suggesting that information deserves full equality with matter and energy, that it should join them in some sort of scientific trinity, that these three things are the main ingredients of reality.
Fredkin goes further still. According to his theory of digital physics, information is more fundamental than matter and energy. He believes that atoms, electrons, and quarks consist ultimately of bits–binary units of information, like those that are the currency of computation in a personal computer or a pocket calculator. And he believes that the behavior of those bits, and thus of the entire universe, is governed by a single programming rule. This rule, Fredkin says, is something fairly simple, something vastly less arcane than the mathematical constructs that conventional physicists use to explain the dynamics of physical reality. Yet through ceaseless repetition–by tirelessly taking information it has just transformed and transforming it further–it has generated pervasive complexity. Fredkin calls this rule, with discernible reverence, "the cause and prime mover of everything."
UPDATE: Kevin Kelly also points me to his excellent meditation on digital physics and the all stars of the field that appeared in a 2002 issue of Wired. The piece is aptly titled "God Is The Machine."