Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!cs.utexas.edu!yale!mintaka!mintaka!nhm
From: nhm@im.lcs.mit.edu (Norm Margolus)
Newsgroups: comp.theory.cell-automata
Subject: Re: Quantum CA
Message-ID: <NHM.90Oct14000827@im2.lcs.mit.edu>
Date: 14 Oct 90 04:08:27 GMT
References: <368@goya.dit.upm.es> <jhaataja.654426447@finsun>
	<6578@castle.ed.ac.uk>
Sender: daemon@mintaka.lcs.mit.edu (Lucifer Maleficius)
Organization: MIT Lab for Computer Science
Lines: 19
In-Reply-To: egnr76@castle.ed.ac.uk's message of 4 Oct 90 09:46:35 GMT

Some people talk about Quantum Computation as being computation at a
small length scale that makes use of quantum interference effects.  I
would tend to reserve the term for microscopic systems which don't
rely on constant communication with the macroscopic realm to make them
work.  Although from the point of view of a macroscopic (classical)
observer QM is mainly a source of noise and difficulty, from a
microscopic point of view it provides wonderful possibilities: a world
with discrete digits and signals, perfect and identical components,
etc.

For a discussion of Quantum Computation and Quantum CA, you might find
the article "Parallel Quantum Computation" interesting -- it appeared
in the book "Complexity, Entropy, and the Physics of Information," SFI
Studies in the Sciences of Complexity, Vol. VIII, Ed. W. H. Zurek,
Addison-Wesley 1990.

	Norm Margolus
	MIT Lab for Computer Science
	Cambridge MA