John K Clark (johnkc@well.com)
Wed, 30 Jul 1997 10:34:33 -0700 (PDT)


On Tue, 29 Jul 1997 Brent Allsop <allsop@swttools.fc.hp.com> Wrote:

>First off, could you define what this "conscious quantum computer"
>is and is not?

I've written several posts on quantum computers, if you can't find them in
the archives I'll re-post them.

>Would the wave function of this event not collapse until I
>consciously represented the event in my mind many years in the

That's the big question, it seems simple but it's extraordinarily difficult,
but perhaps not impossible, to test experimentally. Everett would say that
the wave function doesn't collapse, the universe splits and consciousness
has nothing to do with Quantum Mechanics. The Copenhagen interpretation says

>Can you see the problem I have with all this?

Certainly, but there is no point in keep asking yourself, can things really
be this crazy, because the answer is yes.

>I find such extreme enduring "superimposed states" all very absurd.

Well, it is all very absurd, but it's also true. Suppose the two slits are
one light year away, a polarizer set to at 0 over one and 90 degrees over the
other. One year after they encounter the slits they fall on your film, there
is no interference pattern and it's clear that each photon went through ONE
and only one slit a year ago.

Now suppose that after traveling for one year after their encounter with the
slits and one second before they hit the film you suddenly decide to hold up
a polarizer set to 45 degrees. This erases from the universe all information
on what photon went through what slit and so you see an interference pattern
and it's clear that each photon went through BOTH slits a year ago.

Backward causality? Splitting universes? Observer defined reality? I don't
know, I do know that something very weird is going on. Bohr said "anybody
who is not shocked by Quantum Mechanics does not understand it" another
fellow said " I think it's safe to say nobody understands Quantum Mechanics"
the fellow's name was Richard Feynman.

>Surely any old physical "macro" event, any computer (quantum or not)
>that records and represents the information, or even the information
>traveling up the optic nerve or a rod or cone neuronn in the retina
>firring... can do just as much to "collapse" a wave as phenomenal
>conscious representations can.

Maybe so, but it's hard as hell to prove. It's not Everett's fault we need a
conscious computer, Everett says consciousness does not collapse a wave, but
he'd need such a machine to prove it. The reason the computer must be a
quantum one is that as part of the experiment we need to totally erase its
memory at the lowest level and that means the quantum level.

John K Clark johnkc@well.com

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