Engines of Our Ingenuity

No. 375:
SMALL

by John H. Lienhard

Click here for audio of Episode 375.

Today, we make things very small. 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 the late '60s we set up a computer room for our engineering students. It housed six new Wang calculators with big electric faces. They'd add, subtract, multiply, and divide. They even gave some extras like square roots and logarithms. Of course they had nothing like the power of the calculator that rides, almost as an afterthought, on my wristwatch today.

The students loved those big old machines, and we kept them under lock and key. They were crown jewels. They'd cost $6000 -- enough to buy two fancy new cars in 1967. But machines were shrinking fast. Students finally quit asking for the key in the mid-'70s. By then, discount stores gave them far more in a $20 hand calculator. Since then, mechanical miniaturization has kept burrowing inward.

Now the end of smallness is coming into view. Today we can shape materials down to the level of nanometers. That's a billionth of a meter. It's roughly the spacing between atoms in a solid.

The speed between the magnetic head and the hard disk in your computer is 100 miles an hour. Today, your computer's magnetic heads can ride as close as 50 nanometers from the surface. That's been compared to a 747 trying to fly an inch off the ground. Lubricant films on the surface of your hard disk are measured not in units of length but in atomic layers.

A gadget called a laser well is used in fiber optics communication. It demands miniaturization in yet another form. After your voice has been converted to a pulse of light, the laser well forwards that pulse into a tiny fiber-optic filament. It has to be very fast and very small. Here's a microscopic photo of an ant's antenna. It looms over an array of laser wells. They've been made by depositing single layers of atoms. Some are only a thousand nanometers across.

We're building an invisible world. It's an Alice in Wonderland world where all the rules've been rewritten. We're dealing in devices that change in big jumps as we add or subtract single layers of atoms.

So the end of miniaturization is in sight. We'll learn to control smallness all the way down to atomic dimensions. Then we'll shrink things a little more by handling light instead of matter. And there we reach the end of smallness. But we do not reach the end of change, because ingenuity will go on. When it reaches the end of smallness, ingenuity will simply turn about and march off to the end of something else.

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

(Theme music)


Pool, R., A Small Revolution Gets Under Way. Science, Vol. 247, pp. 26-27.


The Engines of Our Ingenuity is Copyright © 1988-1997 by John H. Lienhard.

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