> Date: Sun, 13 Aug 2000 13:20:23 -0400
> From: John Clark <jonkc@worldnet.att.net>
> Reply-To: extropians@extropy.org
> To: extropians@extropy.org
> Subject: Re: OT: Quantum Computing -- NOT
>
> Franklin Wayne Poley <culturex@vcn.bc.ca> Wrote:
>
> > Could you please explain "more than polynomial time" and
> > "superposition" for us laymen?
>
> I'll give the readers digest condensed version. Let's say X is a problem a
> computer can solve, now let's increase the number of variables in the problem,
> can the computer still solve it before the sun burns out? If the time to solve the
> problem only increases as X^n where n is any integer then we say problem is in
> polynomial time and solvable; but if the time to solve the problem increases as
> n^X it's exponential and not solvable with a normal computer because just a small
> increase in the number of variables yields a huge increase in the time to solve it.
>
> The reason people get excited about Quantum Computers is that when a conventional
> 64 bit single processor computer performs an operation, it does it on one 64 bit number
> at a time. When a 64 bit (actually a 64 qubit) single processor Quantum Computer
> performs an operation the numbers are in superposition so it operates on all 64 bit numbers
> at the same time, all 2^64 of them, more than a billion billion, and any increase in the number
> of qubits the computer can handle will increase its already astronomical power exponentially.
>
> John K Clark jonkc@att.net
Could a very powerful quantum computer in the future then compute numbers
we now consider to be noncomputible because they would require more bits
than all the particles in the universe? (I think such problems such as
computing all the routes between all the cities in the US would be in this
category). If such a computer is operating beyond the physical limits of
the universe, is it metaphysical? Is it doing metaphysical computing?
Does "superposition" mean that it is doing more than one thing at
exactly the same time with exactly the same physical units? If so, that is
a metaphysical concept. This is something we have been talking about on
Robot-for-President in the context of whether a robot with an advanced
quantum robotic controller could be said to be "conscious". If so, how
would we know? If there is some operational way of proving that it is
doing something beyond physical capacity, it is by definition
metaphysical. Does "superposition" do that for us?
I suppose one could then ask if metaphysical means conscious
or sentient. Also, in Charles Tart's text, "Altered States of
Consciousness" the expression "ineffable" keeps coming up. Sometimes these
altered states of consciousness are so extraordinary that people don't
have words adequate to describe them. They are ineffable. Sometimes I find
my own dream states to be that way. I know I have had an extraordinary
dream but when I try to describe it the words don't suffice and the dream
sort of fades away and is lost to memory. I guess my point is that even if
we can prove somehow that quantum robotic controllers have metaphysical
capabilities, that does not prove consciousness as we usually think of
consciousness. Maybe it doesn't prove consciousness at all.
FWP
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