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The first picture shows a fruit fly in flight - I'm sure you've heard people say things like "science
has proven that insects can't fly" and similar things... but obviously we just didn't understand it.
However, scientists now understand it better (and are building models like the one in picture 2, and
others that will do surveillance for the military). Basically, rigid wing aerodynamic models say that they
can't fly - but the motion of their wings is by no means rigid. As I understand it, insects can fly
because: -they flap their wings really really fast (some 200x/sec or so) - clapping - like some birds when
they take off, insects bring their wings together over their back and move them apart swiftly, creating
vortices around the edges of the wings and a region of low pressure above - lift. - the wings rotate as
they flap - horizontal when going down, vertical to minimize air resistance when going up. - the wings
rotate early enough to catch some of the swirling air that was set in motion by the previous flap. (wake
capture) - with bees (and maybe other insects; I don't know) the purpose of hooking two sets of wings
together is to allow them to flap so fast - apparently the nervous system is not fast enough to do this,
so this somehow gets around that.... -insects turn by flapping the wings on each side slightly out of
synch/with different force than the other side. From
http://news.nationalgeographic.com.
The second picture shows a prototype of a mechanical fly being built at UCal Berkley to test
some of these hypotheses. From http://www.sciam.com.
Contributed by Allison Squires, Princeton University.
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