Today, we try to fly on a bee's wings. The
University of Houston's College of Engineering
presents this series about the machines that make
our civilization run, and the people whose
ingenuity created them.
In other episodes we look at
how crude the wheel is in comparison with walking,
or how elementary the airplane is compared to the
flight of birds. We've yet to create a two-legged
walking machine, flapping-wing flight, or a
fin-driven submarine. The motion of living things
is too complex. The helicopter is as close as we've
come to the flight of birds, and it was so complex
we didn't figure it out until 36 years after the
airplane.
Now insect paleontologist Robin Wootton talks about
insect flight. As a student, he first studied
patterns of fossil insect wings etched into stone,
hundreds of millions of years old. He knew their
beauty reflected a complex functionality, so he set
out to understand the mechanics of insect flight.
There's a temptation to think that flying insects
were only a primitive step on the way to birds.
That error comes from the "ladder of creation"
thinking which so misleads us about evolution. We
want evolution to be a process that culminated in
our creation.
But if we're willing to see ourselves only as a
recent splinter in the evolutionary process, then
insect flight makes better sense. Insects have been
around far longer than we have; they're still here;
and they're far more numerous. Evolution has worked
out a lot of kinks in that time.
Insect wings have a tough functional delicacy. A
membrane, only a micron or so thick, rides on a
structure of veins that lets it stretch, bend, or
compress. Those wings can change camber, incidence,
and area in an instant. If they strike an obstacle
they simply bend, then flex back into the right
shape.
Insects can hover, turn in one body length, fly
right side up or upside down, and land on the
ceiling as well as the floor. They are remarkably
evolved and far far too sophisticated to copy.
My 1897 Encyclopaedia Britannica
article on flight gives 16 pages of analysis of
moving birds, insects, and flying fishes -- studies
unaided by motion pictures. The article focuses on
the hope of recreating their motions to accomplish
human flight.
That was six years before the Wright Brothers, and
the author was looking to birds and insects for
counsel on how to fly. But as he talked about work
being done on real flying machines, the futility of
copying nature caught up with him. He lamented the
inherent rigidity of the machines we were finally
being forced to build.
Of course it was in rigid airplanes that we finally
did learn to fly, and in which we've flown ever
since. Now Wootton goes back to study insects in
flight with modern tools. He gives us a lovely
article. But it takes on a darker meaning after we
open that old Encyclopaedia. For, suddenly, we see
that he only reinforces the futility of that
century-old dream of imitating nature.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
