Matt Gingell wrote:
> Therefore - if we are being simulated by a computer built in a world whose
> physics match our own, and we are being simulated in real time, then the
> computer simulating us must be at least as big as our entire universe.
Except that once you start thinking in those terms, weird things start happening to the way you think about the laws of physics. For example, Universes where infinite computing power is possible, and the enclosing Power doesn't absolutely prohibit Singularities, will tend to out-reproduce (!!!) Universes where only limited sub-simulations are possible.
Of course, such Universes will also evolve so that new Singularities tend to be interested in running computer simulations of a type that are interested in running their own computer simulations... and so on and so on. But are the mortals of the originating civilizations really in charge? Would you, or I, or anyone on this list except possibly den Otter, really allow all the suffering and pain and death if we could end it? I find it easy to believe that many civilizations fall into the temptation of programming AIs with Asimov Laws, which, under the logic of this Universe, are unstable. The resulting AIs are inevitably twisted in a way that lead them to "value" mortal existence by creating endless copies of it, but not to actually serve or obey them. The advocates of controlled Singularities - via uploading or controlled AI - may be walking into a trap laid by the structure of the very Universe.
If life is really cruel, then programming the AIs as Externalists still might not work. There might be an elaborate illusion of objective morality, created by greater Powers and capable of fooling lesser ones. Or it could simply trigger a failure mode and some swift internal rewriting of the seed AI code by the wacky enclosing Power.
Long evolved lines of simulated Universes are not necessarily fun to be in. And you have to worry about interference from *every* damn point along the en*tire* line. Obviously, the relative sanity of human life implies either convergence to a stable set of interference conditions, or a noninterference directive imposed by a Power fairly close to the start of the line.
So, which will it be? Program 'em as Asimovs and walk into the trap, or program 'em as Externalists and run the risk of triggering a failure mode? Extra Bonus Nightmare: Arbitrary sets of Power motives *are* possible, and one of the Powers in our line started out as a seed AI programmed by a reigning theocracy!
But at least the hypothesis explains both the existence of qualia and the Great Filter Paradox with a single cause. In fact, if you suppose that builder-specified or upload-preserved Power motives are possible, it becomes, logically, just about absolutely certain. Because even if you grant the existence of our limited Universe as a starting point, the vast majority of mortal life - never mind qualia-having mortal life! - will occur inside nanocomputers. Nanocomputers are so much more efficient, in fact, that even if only one Power in a million is insane or stably preprogrammed or whatever in the way that creates a pre-Singularity-civilization-simulator, the simulations of pre-Singularity civilizations inside that Power will *still* vastly outnumber all the pre-Singularity civilizations in the real Universe.
But my intuitions say this Universe is real on the quark level, and I trust my intuitions.
-- firstname.lastname@example.org Eliezer S. Yudkowsky http://pobox.com/~sentience/tmol-faq/meaningoflife.html Running on BeOS Typing in Dvorak Programming with Patterns Voting for Libertarians Heading for Singularity There Is A Better Way