Or, potentially, one would only need to simulate the minds of any observesers in the simulation, not every particle in the simulated universe.
...for every possible interaction those minds could have with the simulated universe. The only lossless way to simulate a mind's interaction with a universe is to simulate the universe. Further, one must define "observer", as well as simulate accurately what happens to non-"observer" objects, animals, microbes, etc. while "observers" aren't looking.
...for every possible interaction those minds could have with the simulated universe. The only lossless way to simulate a mind's interaction with a universe is to simulate the universe. Further, one must define "observer", as well as simulate accurately what happens to non-"observer" objects, animals, microbes, etc. while "observers" aren't looking.