Jürgen Schmidhuber reviews Programming the Universe: A Quantum Computer Scientist Takes on the Cosmos by Seth Lloyd, in American Scientist:
In the 1940s, computer pioneer Konrad Zuse began to speculate that the universe might be nothing but a giant computer continually executing formal rules to compute its own evolution. He published the first paper on this radical idea in 1967, and since then it has provoked an ever-increasing response from popular culture (the film The Matrix, for example, owes a great deal to Zuse’s theories) and hard science alike.
Given this backdrop, Seth Lloyd appears to be exaggerating when he claims in his informative and entertaining new book that he “advocates a new paradigm” by postulating the universe to be a machine that processes information. However, in the book, which is titled Programming the Universe, Lloyd does somewhat distinguish himself from his predecessors by focusing on the weird world of quantum computation. He lucidly explains what quantum computation is all about, how the process of quantum entanglement seems to involve an instantaneous exchange of information between locations that can be light-years apart, and why this phenomenon unfortunately cannot be exploited to transmit information faster than light. He also describes how quantum computers would be able to solve certain problems much faster than their traditional counterparts.