Open Questions: Physics of Information and Computation

Information is Physical
Rolf Landauer
Physics Today, May 1991, pp. 23-29: Quantum theory holds that obtaining information about a physical system affects the state of the system. This is in conflict with the idea that "information" is something inherently unphysical. The universe itself can be considered to be a sort of analog computer, and the discreteness implied by quantum theory suggests that use of continuous models may be physically unrealistic.

Tom Siegfried -- The Bit and the Pendulum: From Quantum Computing to M-Theory - the New Physics of Information
John Wiley & Sons, 2000: The latest ideas in many branches of physics increasingly take account of the role played by information. The list of such areas includes quantum teleportation, quantum computation and cryptography, complexity theory, black holes, and M-theory.