🚀 go-pugleaf

[From Bruce Abbott (990426.1405 EST)]

>Bill Powers (990426.0631 MDT) --

>>Bruce Abbott (990425.1600 EST)

>>But to say
>>that the complexity of the path does not come from "disturbances" is
>>stretching mightily to make a point, Bill.  If the ant just kept walking on
>>a true heading toward the nest, it would soon encounter barriers and
>>deflecting surfaces that would either push it off course or bring it to a
>>complete halt.

>The disturbances of which you speak are caused by the ant, not by its
>environment.

O.K., have it your way: the environment has nothing to do with it.  The
ant's path is complex because the ant is complex, not because its direct way
home is blocked at multiple points along the way.  Maybe you believe it; I
don't.

>>In their absence the ant would make a bee-line (ant-line?)
>>for the nest.

>You are assuming that the _only_ goal is to return to the nest. I doubt
>that this is ever the case.

Yes I am.  I can do that in order to illustrate a point can't I?  You are
doubtless right if we are discussing real ants in all their marvelous
detail, but I thought I was just using the example to make a point about how
an ant whose only goal was to get to the nest by the straightest path
possible would behave if nothing got in its way.  It's as if I were
attempting to explain the motion of an ideal pendulum and you said "you are
assuming an absence of friction.  I doubt that this is ever the case."
True, but irrelevant to the present argument.

>>Thus, bringing in additional control systems with their
>>sometimes conflicting requirements doesn't change the fact that the complex
>>path observed is a consequence of the complexity of the environment and not
>>the complexity of the ant. In the absence of obstacles the complexity of the
>>ant to which you refer still remains, yet the path is simple.

>You are now asserting that the complexity of the ant can be greater than
>that of its environment.

I assert no such thing.  What Simon was saying is that complex behavior does
not necessarily require a complex organism, that the apparent complexity in
behavior may arise because of the complexity of the terrain over the which
the ant must crawl.  It's a simple point, Bill, and one with which you of
all people should have no quarrel.  The complex waveform of the plot of
handle movement in a tracking task mirrors the complexity of the
distrubances acting on cursor position, not any complexity in the five-line
Pascal model of the control system that can accurately simulate this
behavior.  HPCT is fundamentally simple, yet it is capable of generating
extremely complex actions if the environment requires them.  Not so?

>Also, you are making up an observation to fit the conclusion you want to
>draw. I think it would be very hard to find an ant that simply headed in a
>straight line for its nest, even in the total absence of irregularities in
>the terrain.

This sounds like relevant criticism but it is not.  Again, as should be
obvious, the example of the ant was not intended to provide a realistic
model of a real ant, but to illustrate the point that in the absence of
obstacles an ant controlling for heading directly for the nest would move
directly for the nest. (Not a brilliant point but apparently one that needed
to be made, given your previous responses.)

>Simon's statements about ants were glib, not scientifically useful.

It's a _very_ simple but elegant point Simon was making:  don't assume, just
because the observed actions are complex, that the system producing them
must be complex.  There's nothing glib about it, and certainly there is
scientific utility in keeping it in mind when attempting to puzzle out why a
given system behaves as it has been observed to do. If Simon's insight were
wrong, and complex actions required complex systems to perform them, there
would be no way that the complex waveform of handle movement in the tracking
task could be modeled so well by such a simple set of system equations.  Yet
they are.  The excellent modeling of tracking actions by simple
control-system equations confirms Simon's conjecture.

Bruce