To simulate the universe, would you just take a preposterous point-cloud of planck lengths? And update every single point once for every single planck time?
Shit's crazy. Like, loco.
And yeah, not being able to perfectly predict quantum events would render the simulation merely an approximation of the universe. And it would most likely look and behave radically different than the one we're in.
Had to take a break from the thread for a few hours, and may have lost the idea of the original (also, probably we're several pages further on now...) but...
Are we arguing that a machine in
this universe can simulate
this universe? Goedel would like a word with you, methinks.
However, we simulate universes all the time. Conway's Game Of Life, frexample, or some form of Langton's Ant or a Rule 110 system. (And here I'm restricting to ones without PRNG... Although clearly seeded PRNGs would be similarly deterministic, even if 'actors' in the wouldn't have a chance of predicting it themselves.) Each has a (potential!) universe arising from simple rules but can create complexity. My favourite analogy is that if there were to be a creature
within that 'universe' that (by its own standards) is 'conscious', in some manner that arises out of the 'physical laws' the universe works on, then it probably couldn't perfectly understand the particular environment it is in, let alone know anything about how free electrons float around doped silicon substrates store the data about its universe (which would, if 're-encoded' by the creature's own artisnship into in-universe examples, be too large to store.
Scale that up to what outer Universe might contain
our own sphere of knowledge, and be 'simulating' it, and... And Planck-ticks are Planck-ticks to us, but the FPS of our 'game' in the outer world may be
dreadfully slow... We would't know.
And I
do love linking to XKCD strips, but I reckon I've already given the Pebbles one to this thread before. Look it up, if you don't already know it. ("xkcd A Bunch of Rocks"->your favourite search engine)
Not that I think there's a "guy in the desert" doing this sort of thing. It's as likely to be just a complex but spontaneously[1]-formed symmetry-breaking situation in (meta-)space-time. A bit like a BZ-reaction platter or something.
[1] We can argue over the accuracy of that word later...