EDIT: why the downvotes?
Ok. But this prevents you from directly improving your algorithms.
Yes - which is part of the reason there is a big market for CPUs.
And if the learning mechanisms are to be highly flexible (like say those of a human brain) then the underlying algorithms may need to modify a lot even to just approximate being an intelligent entity.
Not necessarily. For example, the cortical circuit in the brain can be reduced to an algorithm which would include the learning mechanism built in. The learning can modify the network structure to a degree but largely adjusts synaptic weights. That can be described as (is equivalent to) a single fixed algorithm. That algorithm in turn can be encoded into an efficient circuit. The circuit would learn just as the brain does, no algorithmic changes ever needed past that point, as the self-modification is built into the algorithm.
A modern CPU is a jack-of all trades that is designed to do many things, most of which have little or nothing to do with the computational needs of AGI.
A lot of things can't be put into analog. For example, what if you need factor large numbers. And making analog and digital stuff interact is difficult.
If the AGI need to factor large numbers, it can just use an attached CPU. Factoring large numbers is easy compared to reading this sentence about factoring large numbers and understanding what that actually means.
It isn't at all obvious that the brain is even highly efficient at solving AI-type problems,
The brain has roughly 10^15 noisy synapses that can switch around 10^3 times per second and store perhaps a bit each as well. (computation and memory integrated)
My computer has about 10^9 exact digital transistors in it's CPU & GPU that can switch around 10^9 times per second. It has around the same amount of separate memory and around 10^13 bits of much slower disk storage.
These systems have similar peak throughputs of about 10^18 bits/second, but they are specialized for very different types of computational problems. The brain is very slow but massively wide, the computer is very narrow but massively fast.
The brain is highly specialized and extremely adept at doing typical AGI stuff - vision, pattern recognition, inference, and so on - problems that are suited to massively wide but slow processing with huge memory demands.
Our computers are specialized and extremely adept at doing the whole spectrum of computational problems brains suck at - problems that involve long complex chains of exact computations, problems that require massive speed and precision but less bulk processing and memory.
So to me, yes it's obvious that the brain is highly efficient at doing AGI-type stuff - almost because that's how we define AGI-type stuff - its all the stuff that brains are currently much better than computers at!
Not necessarily. For example, the cortical circuit in the brain can be reduced to an algorithm which would include the learning mechanism built in. The learning can modify the network structure to a degree but largely adjusts synaptic weights. That can be described as (is equivalent to) a single fixed algorithm. That algorithm in turn can be encoded into an efficient circuit. The circuit would learn just as the brain does, no algorithmic changes ever needed past that point, as the self-modification is built into the algorithm.
This limits the amount of ...
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).