[danbruc]

Maybe I am ignorant but trying to distinguish between simulation and reality seems to me a lost case right from the beginning. You have to look for a difference but we know neither the rules of the simulation nor of reality. If we look at the universe and find a difference between what general relativity predicts and what the universe does, maybe it even looks exactly like floating point rounding errors - this tells us nothing. It might be an imprecise simulation but it may as well be that general relativity is just an approximation and the real behavior of the universe is floating point general relativity.