Why should we bother simulating things in full fidelity, all the time, just because they will eventually be seen? The only full-fidelity simulation we should need is the stuff being directly examined. Much rougher algorithms should suffice for things not being directly observed.
Of course you're on the right track here - and I discussed spatially variant fidelity simulation earlier. The rough surface area metric was a simplification of storage/data generation costs, which is a separate issue than computational cost.
If you want the most bare-bones efficient simulation, I imagine a reverse hierarchical induction approach that generates the reality directly from the belief network of the simulated observer, a technique modeled directly on human dreaming.
However, this is only most useful if the goal is to just generate an interesting reality. If the goal is to regenerate an entire historical period accurately, you cant start with the simulated observers - they are greater unknowns than the environment itself.
The solipsist issue may not have discernible consequences, but overall the computational scaling is sublinear for emulating more humans in a world and probably significant because of the large casual overlap of human minds via language.
It is entirely practical to store 1 bit (or more) per molecule. Again, infrastructure costs. Can you source this (also Lloyd?)?
Physical Limits of Computation
What I'm skeptical of is that we have evidence that they are practicable; this was what I was looking for.
The intellectual work required to show an ultimate theoretical limit is tractable, but showing that achieving said limit is impossible in practice is very difficult.
I'm pretty sure we won't actually hit the physical limits exactly, it's just a question of how close. If you look at our historical progress in speed and density to date, it suggests that we will probably go most of the way.
Another simple assessment related to the doomsday argument: I don't know how long this Moore's Law progression will carry on, but it's lasted for 50 years now, so I give reasonable odds that it will last another 50. Simple, but surprisingly better than nothing.
A more powerful line of reasoning perhaps is this: as long as there is an economic incentive to continue Moore's Law and room to push against the physical limits, ceteris paribus, we will make some progress and push towards those limits. Thus, eventually we will reach them.
I'm particularly skeptical about how well we will ever do on power consumption (partially because it's such a hard problem for us now).
Power density depends on clock rate, which has plateaued. Power efficiency, in terms of ops/joule, increases directly with transistor density.
I think this is evil, but I'm not willing to say whether the future intelligences will agree or care.
Evil? Why?
I cannot express how much I would rather having never existed.
This is somewhat concerning, and I believe, atypical. Not existing is perhaps the worst thing I can possibly imagine, other than infinite torture.
It is rather a total neglect of care, a relegation of my values in place of historical interest.
I'm not sure if 'historical interest' is quite the right word. Historical recreation or resurrection might be more accurate.
A paradise designed to maximally suffice current human values and eliminate suffering is not a world which could possibly create or resurrect us.
You literally couldn't have grown up in that world, the entire idea is a non sequitur. Your mind's state is a causal chain rooted in the gritty reality of this world with all of it's suffering.
Imagining that your creator could have assigned you to a different world is like imagining you could have grown up with different parents. You couldn't have. That would be somebody else completely.
Of course, if said creator exists, and if said creator values what you value in the way you value it (dubious) it could whisk you away to paradise tomorrow.
But I wouldn't count on that - perhaps said creator is still working on you or doesn't think paradise is a useful place for you or could care less.
In the face of such uncertainty, we can only task ourselves with building paradise.
However, this is only most useful if the goal is to just generate an interesting reality. If the goal is to regenerate an entire historical period accurately, you cant start with the simulated observers - they are greater unknowns than the environment itself.
I believe we're arguing along two paths here, and it is getting muddled. Applying to both, I think one can maintain the world-per-person sim much more cheaply than you originally suggested long before one hits the spot where the sim is no longer accurate to the world except where it intersects with ...
Many folk here on LW take the simulation argument (in its more general forms) seriously. Many others take Singularitarianism1 seriously. Still others take Tegmark cosmology (and related big universe hypotheses) seriously. But then I see them proceed to self-describe as atheist (instead of omnitheist, theist, deist, having a predictive distribution over states of religious belief, et cetera), and many tend to be overtly dismissive of theism. Is this signalling cultural affiliation, an attempt to communicate a point estimate, or what?
I am especially confused that the theism/atheism debate is considered a closed question on Less Wrong. Eliezer's reformulations of the Problem of Evil in terms of Fun Theory provided a fresh look at theodicy, but I do not find those arguments conclusive. A look at Luke Muehlhauser's blog surprised me; the arguments against theism are just not nearly as convincing as I'd been brought up to believe2, nor nearly convincing enough to cause what I saw as massive overconfidence on the part of most atheists, aspiring rationalists or no.
It may be that theism is in the class of hypotheses that we have yet to develop a strong enough practice of rationality to handle, even if the hypothesis has non-negligible probability given our best understanding of the evidence. We are becoming adept at wielding Occam's razor, but it may be that we are still too foolhardy to wield Solomonoff's lightsaber Tegmark's Black Blade of Disaster without chopping off our own arm. The literature on cognitive biases gives us every reason to believe we are poorly equipped to reason about infinite cosmology, decision theory, the motives of superintelligences, or our place in the universe.
Due to these considerations, it is unclear if we should go ahead doing the equivalent of philosoraptorizing amidst these poorly asked questions so far outside the realm of science. This is not the sort of domain where one should tread if one is feeling insecure in one's sanity, and it is possible that no one should tread here. Human philosophers are probably not as good at philosophy as hypothetical Friendly AI philosophers (though we've seen in the cases of decision theory and utility functions that not everything can be left for the AI to solve). I don't want to stress your epistemology too much, since it's not like your immortal soul3 matters very much. Does it?
Added: By theism I do not mean the hypothesis that Jehovah created the universe. (Well, mostly.) I am talking about the possibility of agenty processes in general creating this universe, as opposed to impersonal math-like processes like cosmological natural selection.
Added: The answer to the question raised by the post is "Yes, theism is wrong, and we don't have good words for the thing that looks a lot like theism but has less unfortunate connotations, but we do know that calling it theism would be stupid." As to whether this universe gets most of its reality fluid from agenty creators... perhaps we will come back to that argument on a day with less distracting terminology on the table.
1 Of either the 'AI-go-FOOM' or 'someday we'll be able to do lots of brain emulations' variety.
2 I was never a theist, and only recently began to question some old assumptions about the likelihood of various Creators. This perhaps either lends credibility to my interest, or lends credibility to the idea that I'm insane.
3 Or the set of things that would have been translated to Archimedes by the Chronophone as the equivalent of an immortal soul (id est, whatever concept ends up being actually significant).