[From Rick Marken (950528.1030)]
Bill Powers (950527.2115 MDT) to me:
Wouldn't it be simpler just to read Nachtigall? Maybe he does use a
control-system analysis. How can you tell without reading what he
says?
Ok. Ok. I'll read it. But I wasn't trying to avoid reading it. I was
basing my comments about Nachtigall and my judgment about whether or
not I should take the time to read his book on Bruce Abbott's description
and quotes from the book. I can't read every book that is claimed to be
relevant to PCT. Samples from the book help me decide whether or not I should
invest a lot of time on it. Bruce was nice enough to post an extended quote
from Nachtigall. Here it is, in case you missed it:
The fly approaches the ceiling obliquely from below, at a steep angle,
at a speed of about 25 cm per second. It then flies straight into the
ceiling, and shortly before striking it, stretches out all three pairs of
legs. The fore pair take up a special attitude, held out stiffly upwards
so that they are the first part of the fly's body to make contact. Held in
this way they act as shock absorbers and as anchors, adhering at the
point of contact by means of their claws and pulvilli (hairy pads).
Simulatneously the wings stop beating. Now the fly is clinging firmly
to the ceiling with its fore feet, but its body still has a certain forward
momentum. Like a flywheel on its shaft the fly rotates about its fore
feet and turns its belly upwards, grasping the ceiling with its middle
and hind feet--and there it is, sitting upside down on the ceiling,
without having had to fly upside down first.
Bruce posted this quote [Bruce Abbott (950526.2000 EST)] in response to
my request for an example of "real, systematic, PCT data collection" in
the insect behavior literature. Obviously there is no evidence of real,
systematic, PCT data collection in the above quote. So, either Bruce was
pulling my leg again or he managed to find the one paragraph in Nachtigall's
book that was not an example of real, systematic PCT data collection.
I did not ask whether Nachtigall did a "control-system analysis" of the
fly's behavior; I have seen plenty of control systems analyses based on
data collected by conventional methods and I'm not really interested. I
was interested in seeing examples of PCT research. Obviously, the quote
from Nachtigall is not it.
Nevertheless, I will get Nachtigall's book and read it, if only to prove
that this is not a matter of me being unwilling to "look through the
telescope". It looks like Nachtigall writes well (and/or is translated
well) so it might be fun. And the paragraph quoted above may be the
exception and Nachtigall's book may, indeed, be filled with examples of
real, systematic, PCT daya collection.
By the way, I found a biology book you all might be interested in. I
think it has a lot of stuff in it that anticipates PCT. Here's a quote:
So God created man in his own image, in the image of God created he
him; male and female created he them. And God blessed them and
said to them, Be fruitful and multiply, and replenish the earth and
subdue it; and have dominion over the fish of the sea and over the
fowl of the air, and over every living thing that moveth upon the
earth
There it is; PCT. God is obviously the reorganization system which is
able to create control systems that allow reproduction, fishing and
hunting. The concept of control is clearly articulated in this passage.
This book is well-written and readily available:
God (-5068) _The Holy Bible_, Gideons:Any Motel, USA
I think you should read the whole book -- EVERY SINGLE WORD -- before
you judge whether or not it is relevant to PCT;-)
Best
Rick