Using the Principles of Atomic Physics and Quantum Mechanics

The real obvious killer app for quantum computers is simulating quantum systems. You can build your way up surprisingly far just from the fundamental quantum description. The calculational complexity of doing that is one of the major reasons why we're interested in building quantum computers. James McCrell: I've read many articles and listened to many discussions that lead me to wonder what is meant by the cosmos being a computer program made by some master programmer. Please decipher are those describing actual processes or is all of this talk an attempt to describe the cosmos in understandable terms?