I am looking forward to Seth Lloyd’s forthcoming book (March 2006), Programming the Universe: A Quantum Computer Scientist Takes on the Cosmos.

Here’s an excerpt: “[T]he universe can be thought of as a performing a quantum computation. Because the behavior of elementary particles can be mapped directly onto the behavior of qubits interacting via logic operations, a simulation of the universe on a quantum computer is indistinguishable from the universe itself. The conventional view is that the universe is nothing but elementary particles. That is true, but it is equally true that the universe is nothing but bits – - or rather, nothing but qubits. Mindful that if it walks like a duck and quacks like a duck then it’s a duck, from this point on we’ll adopt the position that since the universe registers and processes information like a quantum computer and is observationally indistinguishable from a quantum computer, then it is a quantum computer.”

For those seeking technical background, I would highly recommend papers by David Deutsch (freely available at arXiv.org).