[From Bruce Abbott (950601.1040 EST)]
Rick Marken (950531.2130)
It's Nachtigall. I probably started calling him Naftigall because I was
unconsciously confusing him with Nosferatu, the German Dracula. I've been
demonizing this poor guy just because his description of flies landing on
ceilings is not a PCT description. This is particularly unjust because
Nachtigall turns out to be a fine scientist. I just got "Insects in
Flight" this afternoon and it is absolutely delightful. I can see why
Bruce got upset at my judgment of the quote from the book. There is lots
of really great stuff in this book, it is clearly written, beautifully
illustrated and one of the translators is a fellow named Roger Abbott
(any relation Bruce?).
I hope so. (:->
I haven't read "every word" but it is easy to see that Nachtigall is a
careful observer and an excellent researcher. It looks like he has done some
very clever analyses of the anatomy, structure and aerodynamics of insects.
I have not been able to find any examples of PCT description or research --
but who cares? Nachtigall did his research in the 1960s, well before
anyone but Bill Powers knew that behavior is the control of perception.
Nachtigall did correctly describe a control system -- but control
engineering had been around for 30 years already. It would have been
remarkable if Nachtigall (like Avery's bee person) have stumbled onto
the notion of systematically testing for results protected from disturbance.
Thanks, Rick; I feel at least somewhat vindicated now. My initial comment
about Nachtigall's work was:
The fascinating bee-as-control-system research by Mandyam Srinivasan
extends work done much earlier from a similar perspective. Werner
Nachtigall (1968) describes some aspects of bee flight as follows: . . .
I then offered an extended quote of Nachtigall's description of the bee's
velocity control system. Later, I used this quote as evidence that
Nachtigall understood the elements of closed-loop control, to support my
thesis that insect researchers have been aware of the concept for a long
time; in this context Srinivasan's work can bee seen as an intellectual
descendent of Nachtigall's work.
What we have been arguing about, apparently, is whether to classify what
Nachtigall did as "PCT research." I thought that Nachtigall's description
of flight velocity control was very much in the PCT mold, but it turns out
that we have somewhat different criteria as to what is and is not PCT research.
Whether Nachtigall may "have stumbled onto the notion of systematically
testing for results protected from disturbance" is difficult to judge from
the book (he certainly hints at it when discussing how the velocity control
system corrects for wind gusts, etc.); I think one would have to read his
_scientific_ publications to answer that question, most of which appeared in
German.
···
At any rate, thanks for the fine review of Nachtigall's book; I wish I could have done as well. Whether we wish to classify Nachtigall as a PCT-style researcher, a "proto-PCT" researcher, or something else, he has indeed written a fine introduction to the elements of insect flight. As you so eloquently said:
Anyone who wants to study
the controlling done by insects in flight would be well advised to read
Nachtigall to find out something about what insects can perceive and what
they can do to influence those perceptions.
Regards,
Bruce