Path: utzoo!attcan!uunet!lll-winken!ncis.llnl.gov!helios.ee.lbl.gov!nosc!ucsd!rutgers!deimos!uxc!iuvax!bobmon
From: bobmon@iuvax.cs.indiana.edu (RAMontante)
Newsgroups: comp.ai
Subject: Re: Robots & free will (was Re: The limitations of logic)
Message-ID: <16699@iuvax.cs.indiana.edu>
Date: 21 Jan 89 02:33:55 GMT
Reply-To: bobmon@iuvax.cs.indiana.edu (RAMontante)
Organization: malkaryotic
Lines: 30

<5782@sdcsvax.UUCP> nschraudolph@ucsd.edu (Nici Schraudolph) writes:
>
>everyday experience. It involved "Schroedinger's cat" in a box, and ended
>with the conclusion that the cat only exists when the box is open.

Not quite.  Apologies to fellow felinophiles...

The question is whether a radioactive atom undergoes fission or not in a
specific time period.  Schroedinger's gedanken experiment is to
construct a box equipped with some poison gas in a canister, the
radioactive atom, and a detector (Geiger counter).  If the atom
fissions, the (presumed infallible) detector detects it and causes the
gas to fill the box.  Now put a cat in the box, seal it up, and wait for
some time.

Is the cat dead after, say, two hours?  That is, did the atom undergo
fission or not?  The only way to answer the question is to open the box
and look (i.e., "make the measurement").

The philosophical dichotomy is that some people say that after two hours
(or whatever) either the cat REALLY IS DEAD, or it REALLY IS ALIVE, and we
just don't know which.  Other people say that UNTIL WE OPEN THE BOX, the
cat is BOTH alive AND dead (or neither alive nor dead) -- the question has
no answer, no meaning in a sense, until that measurement is made.

"Common sense" says that of course the first version is right.  The cat
is either dead or alive, whether we know which or whether we are
ignorant.  But go ahead and prove that common sense -- the act of
"proving" it is in fact the event which is postulated to precipitate a
choice ("collapse of the wave function") in the second version.