> This entails that everything that the laws of physics require a physical object to do can, in principle, be emulated in arbitrarily fine detail by some progra

> This entails that everything that the laws of physics require a physical object to do can, in principle, be emulated in arbitrarily fine detail by some program on a general-purpose computer, provided it is given enough time and memory. But here's the thing: arbitrarily-fine detail may not be good enough. So much of physics ends up being chaotic, to the point where, well, "A consequence of sensitivity to initial conditions is that if we start with only a finite amount of information about the system (as is usually the case in practice), then beyond a certain time the system will no longer be predictable." [Quick quote from Wikipedia - it explains it better than I can.] The brute-force "just simulate everything" approach only works if you can get information about the system at a deep enough level to mitigate the sensitivity of initial conditions - and if there is no such "deep enough" level...