*Quantum Computation and Quantum

Information* Nielsen & Chang.

See for example p. 126

]]>do you have a reference? I’ve suspected otherwise (but not in the current formulation of a quantum computer) and I’ld love to read a paper. sydspoetry@hotmail.com

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nothing more

mathematical undecidability is the proposition itself already

proofing something running systematic = outter set is random?

who knows…….if and only if there is no grey ]]>

Even standard turing machines can solve the halting problem for “some class of computations”. All it says it that a turing machine cannot decide this for ALL computations”. If you’re limiting the set of computations, of course there are turing machines that can decide this.

Example: Construct a turing machine to decide whether or not the following computation halts: The computation to be decided is described by the following turing machine –> Immediately halt on all inputs.

If a quantum turing machine (or quantum calculation as you called it) could throw a wrench into the halting problme, then by definition QTMs would disprove the church turing thesis, which it has already been shown they do not. maybe some other computational model can disprove it, but QTMs are equivalent computationally to standard TMs.

]]>*And if so, is it reasonable to decide that, far from being fantastically profound, Zeilinger’s experiment is actually utterly trivial?*

One could say the same thing about mathematics since most of the cutting edge research (um, for the past few centuries) is about discovering tautologies in made up abstract structures. But these abstract structures help describe models with real value. And discovering and proving the tautologies take considerable effort.

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