For the Love of Physics
From the End of the Rainbow to the Edge of Time — A Journey Through the Wonders of Physics
Free Press, 302 pp., $26
For more than 30 years, the pioneering X-ray astrophysicist Walter Lewin taught core curriculum physics courses to undergraduates at the Massachusetts Institute of Technology. For this alone, he probably ought to be put on the fast track for canonization. To most career physicists in exalted places like MIT and Caltech, undergraduates are things you bump into in the hall.
Now blessedly emeritus, Lewin has apparently not lost one iota of his enthusiasm for his life's work. In "For the Love of Physics" (written with University of Hartford historian Warren Goldstein), he recaps his adventures in the classroom for the benefit of all you graduates of liberal arts colleges who didn't have to take Physics 1 and in later life may feel that something huge and important is missing.
"I've always tried to make physics come alive for my students," Lewin writes. "I believe it's much more important for them to remember the beauty of the discoveries than to focus on the complicated math — after all, most of them aren't going to become physicists." One chapter is titled "The Magic of Drinking With a Straw."
In embracing the layman and laywoman, Lewin has become a star not only of YouTube but also of MIT's OpenCourseWare on the Web ("Free lecture notes, exams, and videos from MIT. No registration required."), which presents nearly 100 of his lectures on Newtonian mechanics, electricity and magnetism, and vibrations and waves. These consist largely of engaging and sometimes alarming classroom demonstrations of such fundamental physical principles as the action of a pendulum, which Lewin demonstrates by straddling a steel plumb bob suspended from the ceiling and whizzing back and forth across the room (a photo of him doing this serves as the book's jacket illustration).
"One of my favorite in-class demonstrations involves two paint cans and a rifle," he tells us. To show his students that air is compressible and water isn't, he fires at both cans, one full and the other partly full of water, and the former explodes ("As you may imagine, it's really very dramatic").
All this is a far cry from quantum theory or, say, the fluctuating two-dimensional branes that some of Lewin's more theoretically inclined colleagues think constitute the physical world's real reality. But Lewin, a physicist of the experimental variety, takes a slightly jaundiced view of theoretical physics. "I'm skeptical of theories that can't be verified by means of measurements," he writes. "[W]hen theory gets way out there, I am reminded of my grandmother, [who] used to tell me, for instance, that you are shorter when standing up than when lying down." She was right, as it happens, and Lewin demonstrates it in class with the aid of some snugly calibrated and exceedingly cool measuring equipment.
Physics can indeed be alarming, especially when you're deep into quantum territory, where information appears to be transmitted at greater than light speed and an electron finds itself in two places at once. Such matters evoke the kind of existential horror that's a lot worse than worrying that your pendulum-borne professor will smack his head against a desk.
Nevertheless, Lewin's joy in communicating "the workings of our world and its astonishing elegance and beauty" is infectious. You will learn a lot from "For the Love of Physics": How to see rainbows in the shower and fogbows in the fog (car headlights; pull over); how to give yourself a halo; how to make a battery with a potato, a penny, a nail and a couple of wires. The concluding chapters are a primer on his specialty, cosmic X-rays (so named because, initially, "they were 'unknown' (like the x in an equation)." In his attractively unworldly (for an author) way, he peppers his book with helpful Web addresses. Those of you who are sick and tired of the printed word can catch him swinging back and forth on YouTube or at ocw.mit.edu/courses/physics/8-01-physics-i-classical-mechanics-fall-1999/video-lectures/lecture-10.
Lippincott is a freelance editor specializing in science.