Today, we find it's harder than we thought to
imitate nature. 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.
Our machines mirror living
beings. We made the first tractors with the horse
in mind. Computers copy the lower functions of our
own brain. We were looking at birds as we struggled
to invent the airplane. That mimicry gives our
machines a certain intimacy with us. But it also
limits what they can do.
When designers first made robotic arms, they had to
unlearn what they knew about their own arms. The
movement of machine joints needn't be limited the
way our elbows and knees are. Remember how
horrified you were when a little girl's head turned
all the way around in The Exorcist?
That'd be easy for a robot.
Look at the airplane: Down through history, we
tried to fly by copying birds. That very fact kept
us on the ground for a long time. We finally had to
see that birds were far too complicated to copy --
at least in this stage of our technology.
Most early airplane designs were ornithopters,
driven by flapping wings. To make a wing propel us
at the same time it lifts us is far harder than it
looks. Birds do it with very complex motions. When
we finally did manage to combine lift and drive in
a wing, it was in the far simpler helicopter. We've
yet to make a workable ornithopter. And we didn't
even learn to make helicopters until a generation
after the Wright Brothers flew.
Birds don't have vertical tails, so at first we
didn't put vertical tails on airplanes to stabilize
their motion. But birds constantly and quickly
adjust their direction in flight. No early airplane
could be controlled with that delicacy. Birds have
high wings, and they land with their tails down. So
it was with the first generation of airplanes. To
learn flight, we've had to shed our knowledge of
birds, one feather at a time.
We've also failed to make submarines that swim like
fish, vehicles that move like animals, or computers
that think like humans. The reason is that nature
does these things in ways that are -- so far -- too
complex to copy.
Did you know that engineering designers are
developing a six-legged walking vehicle for the
army? It's still primitive. We haven't yet mastered
four- or two-legged vehicles. In that sense we've
evolved no further than the insects. The human
brain remains a far distant target for computer
engineers.
Perhaps we shall, one day, come full circle. We
might yet learn to fly with the grace and delicacy
of a bird, or swim like a fish. It's much harder
than it looks to copy nature, but perhaps, someday,
we shall.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
