Thank you for your illuminating observations of Friam discussions, as well as
illuminations of your own depth of knowledge. Of course this is why people
engage in such informal discussions as these: to learn and share ideas. Insults
and denigrations do not come unexpectedly, as I am frankly unsure if there is
any other way to interpret some of your comments (but please correct me I'm
wrong!), and it certainly takes a certain magnitude of courage to expose one's
ignorance in the face of these expectations.
Now, we've all seen the various Vee formations. I had queried about in-flight
rotational dynamics -- do your papers discuss these dynamics, or do you think I
am mistaken that these rotational dynamics actually occur? Assuming they
occur, it seems to me they have not been much studied, though I would love to
be pointed to references. I have seen the Andersson and Wallander paper "Kin
selection and reciprocity in flight formation?" 2004 Behavioral Ecology, Vol.
15 No. 1 (which cites one of your 1970 papers), which proposes a kin selection
model for certain dynamics, which I hypothesize (yes "hypothesize") are better
explained by an energy dissipation model.
Certainly understanding the aerodynamic principles are important as the basis
for these dynamics. But these underlying principles do not change the fact that
birds and living organisms fatigue at different rates and have finite energy
supplies, and if one is looking at a model for in-flight rotational dynamics, I
boldy suggest that once we have a general understanding of the aerodynamical
principles, the technical aerodynamics are secondary to bird fatigue rates in
the various positions within the flight formation.
Why would you simply dismiss the possibility of developing a model which
describes certain observable collective behaviours - particularly when it is an
energy dissipation model, as I like to explore, which is highly amenable to
classical physics?
Hugh
"Modesty is not presuming others know nothing."
----- Original Message -----
From: [email protected]
To: [email protected]
Sent: Tuesday, March 08, 2011 12:20 PM
Subject: [FRIAM] Forget not the Physics, Friam Friends!
It is fun to read Friamers’ hypotheses on formation flight in birds. They
are entirely unprejudiced by any knowledge of the topic. Although knowledge of
a subject is counter-friamistic and takes hard work, I modestly suggest that it
is helpful to understand some of the aerodynamic principles behind formation
flight before hyperventilating too much. The fact is that the Biot-Savart
Law teaches that the asymptotic state is really quite close, as characteristic
of a semi-infinite dipole field. Consequently, aerodynamics shows that for
favorable interaction flyers can utilize uneven Vees, branched Vees, small
Vees, big Vees, broken Vees – and migrating birds use them all. Or look as
though they do! The tip station is theoretically the most unfavorable, but
better than being solo. I have published seven papers on avian flight, and
read and reviewed a good few more, so don’t know very much, but I would not
presume any hypothesis on really why they do it, and who does what to whom.
That’s for the birds!
Peter Lissaman, Da Vinci Ventures
Expertise is not knowing everything, but knowing what to look for.
1454 Miracerros Loop South, Santa Fe, New Mexico 87505,USA
tel:(505)983-7728
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FRIAM Applied Complexity Group listserv
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============================================================
FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
lectures, archives, unsubscribe, maps at http://www.friam.org
