Hi All

It's a tar-baby argument - once you admit the premise that a simulation can be complex enough to have conscious inhabitants like ourselves you're stuck.

An interesting SF version is Greg Egan's "Permutation City" - simulated people (uploads of dead people) discover that turning off their computer hardware is not the end, so long as they exist in a self-contained virtual environment. The whole lot keeps running on every bit of dust that just happens to compute some sub-computation belonging to their simulation - thus the ultimate in distributed computation. The inhabitants decide to simulate an artificial ecosphere with its own set of physical laws - once the simulated inhabitants of the ecosphere determine a self-consistent set of equations underpining their "universe" it breaks away from the original.

The idea is that what makes a universe is not "dust" but the mathematics interrelating it all. Thus any mathematically realistic universe is real, must be real.

Adam