[From Bruce Nevin (2004.05.11 14:43 EDT)]
Bill Williams 7 May 2004 11:25 PM CST--
(11:48 PM 5/7/2004)
You also asked Peter Small about the evolutionary significance of
attractors. I didn't see any reply. However, much earlier, toward the end
of March, he had said
Peter Small (2004.03.27) and again (30th April 2004) --
Chaos is a phased space that describes all the possible states that a
dynamic system can be in. Most of the states are unstable, but within
this space there are many states that are stable (called attractors).
Evolution is about jumping between these stable states.Evolution (extracting low entropy) is about a strategy that causes
these jumps to proceed in a direction that decreases the entropy of a
system. This is arranged by allowing a system to be easily disturbed
so that it will jump out of stable states from time to time. A
selection process (survival of the fittest) ensures that the system
is allowed to resettle only into new stable states that have lower
entropy.
Peter, you must have liked this passage a lot, because over a month later,
on the last day of April, you recycled it under the subject heading "Chen's
Manifesto" with the ID "[Peter Small 30th April 2004]" as context for an
attack on Chen's use of Brownian motion as a metaphor.
However, Peter, you never did reply to Bill Powers' (2004.03.27.0556 MST)
question
What does this searching? How does it know if efficiency is increasing or
decreasing? What tells it to seek a higher value of efficiency? Aren't
there some missing mechanisms in this picture?
The closest thing I could find was your (2004.03.29), saying of that paper
by Lewis that:
Bill Powers dismissed it out of hand on the basis that he'd rejected
that stuff fifty years ago.
So I am glad to see you, Bill Williams, raise the question again. It could
be phrased in a different way. The passage that you were questioning was
Peter Small (2004.05.08) --
Brain imaging techniques seem to support the view that perceptions take
the form of attractors rather than be the product of a control system as
visualized in PCT.
Peter, what if the ebb and flow of perceptions in a perceptual control
hierarchy happened to take the form of attractors? Could you tell the
difference? How? Or do you (Peter) assert that perceptions in a perceptual
control hierarchy "as visualized in PCT" could not possibly take the form
of attractors? If so, what is the basis of this claim? I bet that Martin
would debate that with you.
In the April 30 email quoted above, you (Peter) also said in a similar vein
it is not possible to predict the behavior of complex dynamic systems
using mathematical formulae.
So here are two negatives that you have asserted. Can you prove them? Note
that you would have to prove that the interaction of perceptual control
hierarchies, which can be described using mathematical formulae, cannot
also be described as a complex dynamic system. So these are really two
versions of the same question.
It may boil down to the difference between a descriptive model from the
observer's point of view and a generative model from the point of view of
that which is modeled. Both may concurrently be "true". But, to paraphrase
Hank Folson (2004.03.27), the two should not be confused.
/Bruce Nevin