Bodo_Moeller@public.uni-hamburg.de (Bodo Moeller) writes:
Of course, no quantum computing device that you could run those "programs" on does exist. But as Gilles Brassard puts it, "In my opinion, the theoretical notion of feasible computation should be modelled on our understanding of the physical world, not on our technological abilities. After all, the classical Turing machine itself is an idealization that cannot be built in practice even not taking account of the unbounded tape: any real implmentation of a Turing machine would have nonzero probability of making a mistake. Does this discredit the model? I think not." [2] ... [2] Gilles Brassard, A Quantum Jump in Computer Science (in: Computer Science Today (Springer-Verlag LNCS 1000), 1995, pp. 1-14)
Note that Turing et al did their analysis of what's computable and what's not computable on Turing machines and their equivalents before computers were physically built. --- Dr.Dimitri Vulis KOTM Brighton Beach Boardwalk BBS, Forest Hills, N.Y.: +1-718-261-2013, 14.4Kbps