On Fri, Jun 9, 2017 at 7:11 PM, Bruce Kellett <bhkell...@optusnet.com.au> wrote:
> > Deutsch is out to lunch on this. He appears to assume that a quantum > computer is just using the same algorithms that a classical computer would > use, only executing them in a massively parallel manner. As Deutsch is probably only the second person (after Richard Feynman) to think long and hard about quantum computers I'm pretty sure he doesn't believe that just any old algorithm will do, and I'm even more sure he doesn't believe the classical hardware we use in our computers today can take advantage of a quantum speedup. > > > Scott Aaronson points out: > "*The way a quantum algorithms work is that they arrange for wrong > answers to destructively interfere while the desired answer interferes > constructively. Interference requires that they take place in the same > world*." I agree Interference must take place in a single world, but where did all the information that produced the interference come from, where did the computations that produced all those wrong answers (and a few correct ones) come from? Even the 2-slit experiment will not produce interference if you remove the photographic plate and just allow the photons to continue into infinite space after they pass the slits because then the world splits but the two never recombine again so no interference. You need places for things to become different and also a place for things to come together again for interference to occur. > > Quantum computing does not prove the existence of parallel worlds -- there > is no need for other worlds in which to find the computational power, A large Quantum Computer wouldn't prove beyond any logical doubt that other world's must exist, but then you don't exactly "need" a heliocentric solar system theory to explain the movements of the planets either; you could stick with the Earth centered model if you added enough epicycles of the type used by Ptolemy 2000 years ago . T hen the way the planets moved in relation to the crystalline celestial sphere , the one that has the stars painted on it, could be predicted to the limits of observational accuracy. But you'd need a awful lot of epicycles and calculations would literally be astronomically more complex than with the far simpler heliocentric model. In the same way I think when quantum computers become commonplace programers will take Many Worlds as a given even if they can't formally prove they exist because it's just easier to visualize how they work that way, just as it's easier to visualize a few elliptical orbit s around the sun than visualize a gazilian circles around circles around circles around the Earth. John K Clark -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
