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The supposition is that if you can hold coherence you can basically try every solution to a problem at once.


The point is that if you can hold entanglement long enough, then you can do simultaneous operations in (2N)! - 1 dimensions with N qubits (if I remember by <bra|ket> algebra right - it's been a while).

And since the factorial scales faster than exponentially, you have just reduced whole classes of problems from taking an exponential number of bits to only taking a polynomial number of bits.

Which is awesome, but only tangentially related to sentience.

As for neurons and consciousness, Penrose famously thinks consciousness is a quantum process. I'm not sure we have a good enough model of how neurons actually work to say if he's right. (Probably not, but it's too early to tell.)

It is not categorically impossible, but the scale argues against it. Biologists do not routinely use quantum mechanics to describe inter-cellular interactions (or even, AFAIK, most intra-cellular interactions).

Which, of course, is not to say that quantum computing won't be useful for building AIs - natural human locomotion does not use steel or aluminium, but that does not prevent them from being useful in building trains.

- Jake

Friends come and go. Enemies accumulate.

by JakeS (JangoSierra 'at' gmail 'dot' com) on Sat Aug 27th, 2011 at 02:31:08 PM EST
[ Parent ]
The point is more that from a parallel processing point of view, it's not just about solving equations more quickly. You end up with an architecture that's inherently optimised for associativity, and not for Turing-like linear computation.

E.g. when using Turing machines for video processing, you have to calculate each bit in the frame sequentially. That doesn't make it impossible to do associative recognition and processing, but it's inherently different - theoretically and practically - to working with entire frames, and using an associative memory that can retrieve relevant pattern information in a single operation.

You can fake associative processing sequentially, but certain kinds of processing remain impractical. With associative processing, they may not be.

So it becomes a game changer. Potentially you can't just do things more quickly, you can do entirely new things.

by ThatBritGuy (thatbritguy (at) googlemail.com) on Sat Aug 27th, 2011 at 07:00:20 PM EST
[ Parent ]
Biologists do not routinely use quantum mechanics to describe inter-cellular interactions

Biologist may not, but it appears that evolution does. According to an article by a Cal Tech biologists, in order to achieve the efficiencies observe in photosynthesis the leaf cell has to be using a quantum computational method so as to find the optimal or near optimal path through the cell  for the energy of the photon utilized. I had a link to the article on the computer that was recently killed by lightning.

"It is not necessary to have hope in order to persevere."
by ARGeezer (ARGeezer a in a circle eurotrib daught com) on Sat Aug 27th, 2011 at 10:06:07 PM EST
[ Parent ]
Discovering a natural process may be described, analyzed, with QM - or any other intellectual tool, for that matter - is NOT the same as proving the natural process uses QM - or the intellectual tool.  

She believed in nothing; only her skepticism kept her from being an atheist. -- Jean-Paul Sartre
by ATinNM on Sun Aug 28th, 2011 at 02:54:23 PM EST
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Of course not! I was not suggesting that leaves are conscious. But it is possible that evolution has come upon a process that WE require quantum computing to explain.

"It is not necessary to have hope in order to persevere."
by ARGeezer (ARGeezer a in a circle eurotrib daught com) on Sun Aug 28th, 2011 at 03:47:51 PM EST
[ Parent ]
Hopefully, you were also not suggesting that leaves were "unconscious."

"Life shrinks or expands in proportion to one's courage." - Ana´s Nin
by Crazy Horse on Sun Aug 28th, 2011 at 03:59:34 PM EST
[ Parent ]
ever read 'secret life of plants'?

'The history of public debt is full of irony. It rarely follows our ideas of order and justice.' Thomas Piketty
by melo (melometa4(at)gmail.com) on Wed Aug 31st, 2011 at 05:00:36 AM EST
[ Parent ]


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