Strange Attractors

DRIVING FORCE:
The Natural Magic of Magnets
By James D. Livingston
Harvard University Press, 311 pp.

Wow, a whole book about magnets. I was strangely drawn to it. I couldn’t put it down.

But seriously, folks. Ever wonder where magnets come from, how they’re made, what they’re used for? Let me tell you, there’s a worldwide industry churning these things out in all sorts of shapes and strengths, for all sorts of purposes, for all sorts of prices.

There are the doughnut-shaped tokamak mega-magnets used to generate containment fields in attempts to harness nuclear fusion. There is also the store I wandered into in Vegas, which sold nothing but fridge magnets of various designs. As it turns out, almost every mall in Nevada has a fridge-magnet store. They’re marching north, like killer bees.

And as they do, it’s not the fridge manufacturers who are getting rich, but the magnet magnates. Japan and the United States may vie for technical supremacy in high-tech-magnet design, but China is looking to dominate the market in magnet production.

Our guide to the field of magnetism is James D. Livingston, who worked in research and development for 30 years at General Electric and now teaches at the Massachusetts Institute of Technology – a guy who knows his stuff.

He starts, as he should, with his own boyhood fascination with magnetic repulsion and attraction. Toddlers are fascinated with wind-up toys. How do these inanimate objects move with a life of their own? As they get older, kids figure out the mechanics of clockwork toys and the mystery recedes. Then they encounter magnetism.

Action at a distance. Magnetism is often a kid’s first confrontation with forces visible yet unseen, tangible but infuriatingly difficult to grasp. The immediate impulse is to ask Mom or Dad what causes this magical effect. Good luck, Mom and Dad. Magnetism is one of those moments when junior realizes: Hey, these characters don’t know everything.

Parents facing the prospect of a child about to ask about magnetism have two choices. They can prepare for the question by reading Driving Force, or they can just press the book into the kid’s hand when the question comes up. I’d recommend both. This is a good book for bright kids to read. It’s also a refresher course in stuff educated adults should know but may well have forgotten.

Quick: What’s the difference between volts, amps and ohms? What’s superconductivity? Why do magnets have an affinity for steel but not for silver?

Don’t know? Don’t worry. Driving Force explains it all, clearly and painlessly.

True, the book has the exuberance of one of those instructional films from junior high – Our Friend the Mighty Magnet. Imagine what the world would look like without magnetism. No compass, no rise of the European mercantile nations. No supercolliders, no TV, no magnetic resonance imaging, no fridge-magnet stores. Some people – well, the Unabomber – might prefer a world without magnets, but not me. To be honest, I even liked those instructional films in junior high.

Want a taste of the questions that bedevil conscientious parents? “Mom, the Earth is a giant magnet, right? Does that mean all the planets are magnets?” No. The Moon has no magnetic field, nor does Venus.

“Well, how come?” Ahem, it has to do with the mineral composition of the various worlds, maybe also the temperature at which they were formed.

“Okay, but can the Earth’s magnet go wonky, like in the Bermuda Triangle? I heard that it could.” Ah, yes. Geological evidence indicates that the Earth’s magnetic field has periodically reversed itself. What is north was south and vice versa, and God knows what was in between.

“And will there be supersonic magnetically levitated trains in the future?” Not if Via Rail has anything to do with it.

Sorry. That last crack was gratuitous. The correct answer is that mag-lev trains are about as imminent as a real-life Magneto, whose mutant super power, as you know, is magnetic control over the elements of the Earth. Now put the comic book down and go to sleep.eg

  • Globe and Mail May 1, 1996