Engines of Our Ingenuity

No. 1482:
BLACK BOX

by John H. Lienhard

Click here for audio of Episode 1482.

Today, we ask what's inside a black box. 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.

The word "black box" hasn't been part of our language for long. It first meant a closed set of electronic gear. Over time, it's come to mean any function hidden from sight. In fact, it's turned into a metaphor for a retreat from understanding. When we call the flight recorder of an airliner a "black box," we acknowledge that it's to be opened only in the most dire circumstances.

When I was a kid, we stocked radio tubes on the shelf like light bulbs. When one burned out, we replaced it. If a transistor fails in today's radio, we replace the radio. Radios are black boxes -- I have almost no idea what's in mine. Our computers, car transmissions, and clocks have all become black boxes. Even their labels tell us they can be opened only by factory representatives!

How do you and I do with questions like, "What's a universal joint?" or "What does a carburetor do?" We're far less likely to know these things today because cars themselves have become black boxes. Car owners once looked right down into their Model-T transmissions; and when they broke, they had to know how to fix them.

Automobiles once taught us applied mechanics. Radios taught a whole generation about electronic circuitry. I got my grounding in internal combustion, aerodynamics, and electricity by building model airplanes. In 1943 we had to wire a coil, condenser, and battery together just to make the spark plug fire.

Now the personal computer is a black box. I might nerve myself up to open mine and replace a component. But don't even think about asking me to explain how my Pentium chip works.

The lingering question is, "What knowledge do we need?" Few of us have any reason for knowing the workings of an old Ford transmission. At the same time, I wish I knew more about the automatic transmission in the car that takes me to work.

The people who invented my transmission were the best of a generation that cut its teeth on Ford planetary gears. But today's population includes very few people who understand today's transmissions. Automobiles in the year 2050 will have to be built by people who don't understand the transmissions on today's cars.

They'll be supported by knowledge contained in computers that also lie beyond their understanding. So we're systematically being separated from the black boxes that serve us. As we handle sophisticated systems without looking inside the complexities that make them up, knowledge itself becomes black-boxed. Someone who knows about computers may know nothing about cars. John Donne's poetry can remain a black box for a student of Pushkin.

How do we teach our students that the boxes around them aren't Pandora's boxes -- that they can be opened? How do we teach them that what one fool can do, another fool can also do -- that they're smart enough to open anyone else's black box? Students have to know that invention inevitably means working inside black boxes.

I'm John Lienhard, at the University of Houston, where we're interested in the way inventive minds work.

(Theme music)


This is a greatly reworked version of Episode 94.

I tried this script on an engineering colleague. He immediately rattled off more cases. For example: The Mac, Windows, or Linux operating system on your computer is far beyond our reach. We once mixed our own motor oils for our various internal combustion engines. Now a label on the can stipulates which machine that particular oil is meant to serve. Most chilling of all is the label on some machines, "No replaceable parts. Do not open."





The Engines of Our Ingenuity is Copyright © 1988-1999 by John H. Lienhard.