New blog post on Artificial Intelligence and the Church-Turing thesis (coming out of discussions here with).
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- wrote: "If a mind is simulated on a digital computer does it disappear between clock ticks?... I have a vague recollection that Greg Egan used this idea in one of his novels."
Right, Egan's Permutation City starts out with an experiment that answers your first question. And the answer they get, of course, is that from the mind's own viewpoint it does not disappear between clock ticks.May 10, 2012
- Re: "Landauer's ln(2)kT cost of bit erasure ..." reminds me a a funny daydream I've had. People have tried to build "reversible computers" every now and then, for various reasons. (I can recall several: one having to do with database updates, to make a transaction rollback simpler/faster/better. A second had to do with avoiding checkpointing: if a calculation produces an error, then go backwards and try a different path. A variation of this has resulted in the speculative execution units on modern cpu's.)
Anyway: whenever one has a branch in the code, the number of possibilities double. And, lord knows, code has zillions of branches. Its all well & fine to do speculative execution on both branches, but if/when one finally decides to keep one branch, and throw away the others, one pays the bit-erasure cost. That there is some vague resemblance between this combinatoric explosion of branches, and the quantum Everett many-worlds interpretation, lays the foundation of the daydream.
The daydream then goes like this: Suppose one takes Nick Bostrom's simulation argument at face value. Suppose one needed to build a vast computer, in order to simulate physics for an entire universe. Suppose one was worried about heat, and needed to avoid heat from bit-erasure. So, what does one do? One makes as many equations of physics to be time-reversible as possible, and, for the rest -- any branches: well: use quantum mechanics for those. So, perhaps, if we live in a simulated universe, perhaps our laws of physics are what they are because the Simulator had to avoid heat costs! The daydream can then peter out or wander off in various rancid directions, involving Planck scale and the entropy of Unruh radiation and 'tHooft's boundary conditions on black holes and the like. Like, maybe gravity is just bits attracting each other, so that a massively-parallel computer can avoid the problem of shipping bits to distant parts of the galaxy (which is a real bottleneck for current generation supercomputers: non-local algorithms are really fucked).May 10, 2012
- What about the old, science fiction trope, that a super computer would view us as less than ants and destroy us carelessly? I know, arguments from fiction are a little shaky, but still it seems presumptuous to imagine that super intelligence would naturally arrive at the same moral principles that we, with our puny brains, have. Still, I'm not particularly afraid.
Yes, the natural answer is that the slow computer is conscious, only on a slower timescale. But, still, it bothers me. For instance, what if you recorded the state of the computer at each tick of the clock and wrote it down in some notation on a giant notebook. You do this for a long while, then take the first page of the notebook and use it to build a model of the computer in the identical state to the conscious computer during the first clock tick. Then you destroyed your model, waited the appropriate amount of time and did it again with the second page, and then the third, and so on. Would your series of models still be conscious? The only difference, it seems to me, is that your models would not be causally linked (at least directly--I suppose, since the images derived from the first, sentient computer, the models are causally linked).
Sorry if I sound like a crank here--it's hard not to when talking about consciousness. And apologies if I'm merely, unconsciously, echoing an argument from Permutation City. Still, I'm puzzled.
Thanks for reminding me of Permutation City. I'll pick up Blindsight.May 11, 2012
- Blindsight by Peter Watts is an absolute must-read book!May 11, 2012
- I see ants all the time and I don't destroy them unless they start messing with my food =). Sometimes I even watch them and find them fascinating and inspirational as I watch how they solve problems such as cooperating to carry a much larger object up a wall or sending random members to explore the search space in different directions. Don't forget also that although we are much larger and vastly more intelligent than bacteria and viruses they can still kill us at large enough numbers if they can infiltrate our security. Which they manage often. So there is hope yet. heh
As for your notebook problem - I don't see an issue. I don't see a difference between your scenario and teleportation (copy mind, send as radiation then destroy body and reassemble elsewhere) or cryogenic suspension - if they were ever invented..May 11, 2012
- I'm turning off comments here but leaving them on here: https://plus.google.com/u/0/+RichardElwes/posts/WAQixRkBhqhJan 23, 2015