On 12 Jan 2009, at 17:24, Mirek Dobsicek wrote:
> > Thank you for a quick answer! I'll take a look at it, my curiosity > approves additional items on my TODO list :-) Manage keeping finite your todo list :) I have finished the reading of the paper I mentioned (Deutsch's Universal Quantum Turing Machine revisited) and I see they have very similar problems, probably better described. The paper mentions (but does not tackle) an old problem already described by Shi 2002, which made me think at the time that the notion of Universality is a bit dubious in the quantum realm. To sum up: is there a (never stopping) quantum counting algorithm? I think I can build a Quantum UD from it, well in case the Shi problem is not too much devastating. But here, and now, I got a feeling there is just no quantum counting algorithm ... Cheers, Bruno PS Note that AUDA (the arithmetical UDA) is in principle already able to solve completely that problem. It is still possible that "the material hypostases" of the self-observing *classical* universal machine lacks both the kestrels and the starlings, and their descendant combinators in which case comp predicts that physics is NOT Turing Universal. Comp would predict that not all natural numbers are in any possible nature or physics! "in principle" only because the translation in arithmetic leads to very complex arithmetical formula (bounded by PI_1 IN Arithmetical Truth, if you know a bit of degrees of unsolvability. I will perhaps explain a bit of this, but take it easy for not making explode the todo list :). Note the beauty of comp: even if there are no physical universal machine in the physical universe (including the physical universe(s)), *you* (and other persons) are and remains universal machine. We do not live in physical universes, we just traverse them to be able to chat some bits, perhaps. The first persons would be spiraling through an infinite sequence of rotations, if said through an image. http://iridia.ulb.ac.be/~marchal/ --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-l...@googlegroups.com To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~----------~----~----~----~------~----~------~--~---
