From newshub.ccs.yorku.ca!torn!utcsri!newsflash.concordia.ca!vax2.concordia.ca!eamon Mon Nov  9 09:36:48 EST 1992
Article 7517 of comp.ai.philosophy:
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>From: eamon@vax2.concordia.ca (Eamon Egan)
Subject: Re:  Ginsberg and Human intelligence vs. Machine intelligence
Message-ID: <5NOV199211303565@vax2.concordia.ca>
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References: <1992Nov4.234237.21662@Csli.Stanford.EDU>
Date: Thu, 5 Nov 1992 16:30:00 GMT

In article <1992Nov4.234237.21662@Csli.Stanford.EDU>, 
avrom@Csli.Stanford.EDU (Avrom Faderman) writes...
>samsr@zinfande.unx.sas.com (Mark S. Riggle) writes:
> 
>| In the Strong AI vs. Weak AI hypothesis arguments, it is easy to forget 
>| the very special treatment of consciousness in quantum physics and that 
>| it should be accounted for.
> 
>In _some_ versions of quantum physics, perhaps.  There are several versions 
>of Q.M., however, entirely compatible with the data, that accord no such 
>special status to a conscious observer.  A paricularly interesting one is 
>the "many-worlds" interpretation, proposed by Hugh Everett.  On this view, 
>rather than one time-line, the universe has a branching time-axis. 
>"Superpositions of states," like the one Schroedinger's cat is supposedly 
>in before the box is opened, are really just cases of parallel time-lines 
>having different states without the experimenter knowing which line
>he/she's in fact in.  When the box is opened, the experimenter finds out. 
> 
>Although this view seems slightly counterintuitive at first, it is no more 
>so than many other consequences of modern physics, and _certainly_ no more 
>so than the "conscious observer causes collapse" theory.
> 
>For those that disagree, imagine that, instead of a cat, a conscious 
>(aren't cats at least a little conscious, anyway?) observer, such as a 
>person, were trapped in the box.  Now, _from_the_perspective_of_an_
>_experimenter_outside_the_box, all Schroedinger's assumptions still hold.  
>So we must conclude that even the person inside the box is, from someone's 
>perspective, in a superposition of states.  Therefore "conscious
>observation" has nothing to do with the collapse of the wave function.

Someone *else's* conscious observation has nothing to do with the collapse 
of the wave function *for me*.  Just as *my* conscious observation has 
nothing to do with the collapse of the wave function *for someone else*.
Wave function collapse, in the pure sense, is itself relative to each 
consciousness.  "so and so's friend" (I forget whose) is a published
though-experiment which puts a conscious observer in a superposition of 
states with respect to another observer.

However, that being said, I think that real quantum mechanics in practice 
takes the wave function to have collapsed after the effect has propagated 
up to the macro level.  At this point the heisenberg whatsits have been 
rendered insignificant, and nothing weird is any longer observed.  That's 
why Schrodinger's cat is only interesting as a thought-experiment.

If anyone knows what I'm saying better than I do, please straighten me out.

------------------------------------------
Eamon Egan
Philosophy, Concordia University, Montreal


