Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uwm.edu!cs.utexas.edu!uunet!mcsun!ukc!edcastle!aipna!cstr!tim From: tim@cstr.ed.ac.uk (Tim Bradshaw) Newsgroups: comp.ai Subject: Re: Artificial vs. ''real'' intelligence Message-ID: Date: 27 Jul 90 21:01:21 GMT References: <1990Jul2.182411.4441@king.mcs.drexel.edu> <604@dlogics.COM> Sender: news@aipna.ed.ac.uk Organization: CSTR, University of Edinburgh Lines: 44 In-reply-to: dsa@dlogics.COM's message of 13 Jul 90 18:34:42 GMT >>>>> On 13 Jul 90 18:34:42 GMT, dsa@dlogics.COM (David Angulo) said: > OK, I think I'm getting a clearer picture on what he's saying. It sounds > as if his basic misunderstanding comes in simulating wave equations. You > can simulate a sin() function because it really exists in the physical > universe. Whether or not Schroedinger wave equations exist is still > an area of contention. It is the RESULT of these wave equations that can > be used. When you do this, you end up with a probability density. This > CANNOT be "simulated" because it doesn't pertain to reality. It does not > inform us that a particle exists at a certain point at a certain time. It > only tells us what the probability of finding a particle at a certain point > at a certain time is. Sure, all he's saying is that you can perfectly simulate anything you can measure; and good quantum mechanists are only ever concerned with what you can measure: QM is really *about* what you can measure (or `observe' in the jargon...). Of course this raises the interesting question of what makes the observation, which has at least historically been a point of discussion among quantum theorists. The problem is that you must make an observation of a system to put it into a definite state (`collapse the wave-function/state-vector'), and this process is quite important in QM. Simple-mindedly you say that a `conscious observer' is what you need to make an observation in this sense. Of course, when you start getting interested in how to build such a conscious observer (which is one goal of AI in a sense) you have a problem because you're trying to construct a physical system which itself must obey QM, and just what is making the observation and where it's being made become obscure to say the least. Simple mindedly again, you can be lead to believe that an observer is not a physical system. The original solution to this was the Copenhagen interpretation, which really says `None of this matters, because you don't need it to do physics'. It seems that you would need it to understand what building a conscious observer is though. Well it's too long since I thought about this, but I think there are formulations of QM which get around this or have some hope of doing so. If anyone out there knows about this I'd like to hear from you, otherwise I'll have to look it up... --tim Tim Bradshaw. Internet: tim%ed.cstr@nsfnet-relay.ac.uk UUCP: ...!uunet!mcvax!ukc!cstr!tim JANET: tim@uk.ac.ed.cstr "Quis custodiet ipsos custodes?"