The difference is that a simulation is an approximation of a copy. Simulation code has to be complex because we want to preserve those features that are important, which is never a straightforward problem.
An exact simulation of the universe down to the last particle would be a very simple program, probably a few hundred bits to specify the laws of physics. But it would require a computer larger than the universe to represent its quantum state (as a string of 10^122 bits). It would take even longer to run the simulation because the best known algorithms for computing the wave equations are exponential, or 2^(10^122) steps. So we approximate. -- Matt Mahoney, [EMAIL PROTECTED] ----- This list is sponsored by AGIRI: http://www.agiri.org/email To unsubscribe or change your options, please go to: http://v2.listbox.com/member/?member_id=8660244&id_secret=80322602-300c67
