Today, let's see what happens when two or more
technologies join forces. 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.
I want you to try a little
experiment the next time you have a moment. First
find three metal masses -- nuts, bolts, lead
sinkers -- whatever's handy. Now hang one on the
end of a thread and swing it. The motion is simple
-- a little pendulum that moves back and forth in
just one way. Next, take a longer length of thread
and attach all three masses along its length. Space
them about two feet apart. Then hang this string of
masses from the ceiling.
Start this system swinging and watch what happens.
No matter how they start out, they're soon moving
in the most unexpected ways. The middle one might
momentarily stop dead, while the other two gyrate
around it. They might all move in the same plane,
or they might swing in circles. And the patterns of
movement keep changing. Going from one mass to a
system of three masses takes us from a motion we
can easily understand to one that mystifies us.
Our technological systems are like that. In October
1987 we saw what happened when a
computer-controlled stock-market responded to a
ripple in the economy. We'd told our computers how
to respond to certain changes, but we weren't at
all prepared for their aggregate response. We were
stunned to see them flock together into the
greatest one-day stock-market crash the world had
ever seen.
That same sort of thing was true of the Three Mile
Island and Chernobyl reactor failures -- so many
elements were interconnected that an operator
couldn't diagnose a change quickly enough to take
the right corrective action.
And yet, complex systems of technologies are at the
heart of the machinery of today's society. A friend
of mine -- an engineering designer -- recently came
back from Europe. "John," he said, "I had a
remarkable experience. I had to call home, so I
picked up the phone in my hotel, pushed a few
buttons, and found myself talking to America." I
looked at him and said, "So what?"
He said, "Stop and think. How many terribly complex
systems had to be put together to give me that
convenience -- the space technology to put up a
satellite, the electronic technologies on the
ground, the radio technologies in the sky, the
hotel management systems, and so on and on!"
So I did stop and think. Today's engineers have to
worry as much about combining technologies
effectively as they have to worry about inventing
them. Ill-concieved systems threaten us with
terrible mischief. Well-combined technologies stand
to present us with amazing benefits and
conveniences. And the intellectual challenges of
complex-systems design are dazzling.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
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