Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!ucsd!rutgers!rochester!pt.cs.cmu.edu!andrew.cmu.edu!ap1i+ From: ap1i+@andrew.cmu.edu (Andrew C. Plotkin) Newsgroups: comp.ai Subject: Re: Robots & free will (was Re: The limitations of logic) Message-ID: Date: 11 Feb 89 01:32:26 GMT References: <3328@sdsu.UUCP> <43228@linus.UUCP> <539@uceng.UC.EDU> <3550@ingr.com> <226@UNIX386.Convergent.COM> <1374@arctic.nprdc.arpa> <9256@cit-vax.Caltech.Edu> <263@edai.ed.ac.uk>, <5895@sdcsvax.UUCP> Organization: Class of '92, Carnegie Mellon, Pittsburgh, PA Lines: 23 In-Reply-To: <5895@sdcsvax.UUCP> />If the wave function collapses only when observed by consciousness, />then one could devise from this an experimental test of whether a robot />- or indeed any artificial or natural creature - had consciousness or not. / /Neat idea - but how are you going to check the result of your consciousness /test? Look at it? You do that, and naturally you'll find the wave function /collapsed - because you looked! I shouldn't have brought up the phrase "the function collapses" -- it seems to be getting in the way. The point of the quantum observer-observed interaction is that the experiment is affected by whether "someone is looking" (whether an observation has been made.) This is true even if the observation has trivial effect on the observed. (For example, an observation can be made as to whether an electron has gone past. That observation will affect the electron; *but* experiments can be designed in which the *amount* of effect is too small to screw things up.) In other words, the film in the "two-slit experiment" will show fringes if the slits were not watched individually, and no fringes if they were. Looking at the film afterward has nothing to do with anything; the state function has already collapsed. The experiment measured whether the collapse happened to the particle before the slits or after them. --Z