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From: hawley@icot32.icot.or.jp (David John Hawley)
Newsgroups: comp.ai.philosophy
Subject: Re: emergence
Summary: What is 'functional equivalence' of components in emergent systems?
Message-ID: <7738@icot32.icot.or.jp>
Date: 4 Oct 90 05:22:02 GMT
References: <3531@media-lab.MEDIA.MIT.EDU> <JSP.90Oct3123040@milton.u.washington.edu>
Organization: Fifth Generation Computing Systems (ICOT), Tokyo, Japan
Lines: 25

In article <JSP.90Oct3123040@milton.u.washington.edu> jsp@milton.u.washington.edu (Jeff Prothero) writes:
>Perhaps the key characteristic of an 'emergent phenomenon' is that it
>has interesting characteristics which it possesses *independently* of
>the underlying (implementation) system?

An implementation is a system that obeys some specification. 
Practically, specifications are incomplete, and in fact it may be impossible
to simultaneously give a complete specification and verify compliance.
If emergent properties of some system are not predictable from the behaviour of
the components thereof, then it is impossible to predict which aspects of the
component's behaviour might be relevant to any hoped for emergent property.

For example, the apocryphal story of disk drives gyrating around the floor
when presented with certain pattern of disk accesses, seems to be an example
of a phenomenon (gross physical movement) emerging from the interaction of
a program, OS, and a storage device. The fact that the storage device was
not implemented as solid-state is crucial.

In other words, the implementation is the interesting thing, and not the
specification.

---------------------------
David Hawley, ICOT, 4th Lab
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ICOT, 1-4-28 Mita, Minato-ku, Tokyo 108 JAPAN. TEL/FAX {81-3-456-}2514/1618