Today, an archer fish learns to shoot. 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.
A story is told about a great college swimming coach. His
swimmers won NCAA Championships year after year. He was flamboyant, exciting,
charismatic. He'd pace the rim of the swimming pool shouting instructions,
adjusting strokes and body orientations. He had a fine eye for what each swimmer
needed to do. Then one day, he tripped as he ran along the edge of the pool.
He fell into the pool and drowned. It turns out he'd never learned to swim.
We laugh, not because it's ridiculous, but because we wonder if it really could
happen. Can one function on the basis of a purely intellectual understanding of
a physical skill? Well, meet the archer fish. This inch-long creature
feeds on insects that it shoots out of the air. It spits water droplets from just
below the surface, and nails flying insects five feet away. Think of all that
involves. The fish has to lead the moving insect and adjust the angle of its shot
as the prey moves away. It has to correct for the light refraction between water and air.
Now German ichthyologists study these fish. They find that, like top-notch swimmers,
the fish have to practice. At first their technique is poor; their aim is lousy.
They become fine marksmen only by trial and error practice -- as expected.
Then a startling discovery: When they put several inexperi-enced fish in the tank and
fly insects over it, only one alpha fish practices. He becomes quite good at shooting
down insects, while the others just watch. So the frustrated scientists finally remove
that one fish. When they do, the other fish begin shooting down insects. They've
become just as able as the one fish who'd prac-ticed. They've learned entirely by
watching, not at all by doing.
That flies in the teeth of all we believe about human education. It simply shouldn't
happen that way. But it does. And, if that unfortunate swimming coach had been an
archer fish, he wouldn't have drowned the first time he found himself in the water.
The catch is that we have to undertake so much without practice, in our complex
world. That's what college should be all about -- preparing for the unexpected. We're
so often told that people learn faster in the school of hard knocks. Well, they do --
up to a point. But we'd be dead in the water if we couldn't deal with things beyond our
experience. That's what we do when we de-sign any large system. Politicians and businessmen
constantly deal with such issues, and they make a mess of them only some of the time.
You and I are more like archer fish than we realize. Indeed, that story about the swimming
coach is flawed just because he would've been rather well prepared for his unexpected immersion.
All the most serious issues that rise in our face today are ones in which none of us can claim
a whit of experience. Bismarck understood that, when he said, Only a fool learns from his
own mistakes. The wise man learns from the mistakes of others
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
C. Brodie, Watch and Learn. American Scientist, Vol. 94,May-June 2006, pg. 218.
http://www.naturia.per.sg/buloh/verts/archer_fish.htm
Watch and Learn
The Engines of Our Ingenuity is
Copyright © 1988-2006 by John H.
Lienhard.
