[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Naive WAIR Question

OK, here's my naive problem with WAIR (which is no doubt addressed in
the paper, but I and others don't have access to it).

According to HP Holtz's very helpful summary, the wing motion pushes
the bird "downward", towards the "ground".  (The quotes are because
the ground may be inclined, of course, so that "downwards" might be
horizontal; but you get the idea.)  But that is course exactly the
opposite of what wings do in flight, when they impart upward rather
than downward thrust.

So hypothetical WAIRing dinobirds that switched to flying would need
to suddenly start making a completely different motion -- as HP
Hecht's _New Scientist_ article mentions:

        High-speed photos revealed the running birds beating
        their wings from head to foot and back. Importantly,
        the direction of this movement is 90 degrees from that
        used for flying, which involves flapping from above
        the back to under the belly.

Isn't there also something in the morphology of extant avian feathers
that inherently suits them for generating upthrust?  I am no expert,
but I seem to recall that the cross-sectional profile of a flight
feather is curved in much the same way as the wing itself.  Is this a
correct recollection?  If so, then you'd think that those WAIRing
dinobirds that were best adapted for WAIRing would be precisely those
that were _least_ adapted for flight.

What am I missing?

My other problem with the WAIR theory of flight development is that,
as any lovers of Italian or English football will agree, the photo of
Ken Dial at http://www.nsf.gov/od/lpa/news/03/pr0308_images.htm shows
that he is really none other than Gianluca Vialli :-)

 _/|_    _______________________________________________________________
/o ) \/  Mike Taylor   <mike@miketaylor.org.uk>   www.miketaylor.org.uk
)_v__/\  Never look a gift-chicken in the beak.

Now available: _Child's Play_, my wife Fiona's CD of kids' music.
Download free sample tracks; buy on-line or by mail-order.