Book Review : Capturing the Elusiveness of Physics

Longing for the Harmonies: Themes and Variations From Modern Physics by Frank Wilczek and Betsy Devine (Norton: $19.95; 361 pages)

Suppose all of the scientists in the world are brought together into one huge arena--the L.A. Coliseum wouldn’t hold them--and are asked to write down all of the unanswered questions in their field.

These questions are then collected and put on a giant blackboard. The scientists then go home to their laboratories and continue their work. As they come up with answers, they notify the keepers of the blackboard, who cross off those questions from the list.

Eventually, which may be a long time, all of the questions are answered. Would the world then possess perfect knowledge of everything?

No way. For it is both the paradox and the pleasure of knowledge that each answer begets new questions that you didn’t even know were questions before. Nowhere is this basic fact more evident than in physics, which has labored mightily for three centuries to explain the physical world around us and is still scratching its head in wonder.

Major, Fundamental Problems

“It is no small part of the charm of physics that, after more than 300 years of astonishing progress, there remain absolutely major and fundamental problems,” Frank Wilczek and Betsy Devine write in their engaging but difficult book, “Longing for the Harmonies,” a valiant effort to make the details of modern physics accessible to general readers.

They almost succeed. The trouble is, the details of modern physics--the ins and outs of quantum mechanics, quarks, fields, Higgs bosons, muon decay, QED (quantum electrodynamics) QCD (quantum chromodynamics) and the like--cannot be made accessible to readers without at least an undergraduate degree in the subject.

But do not despair. There’s plenty in this book for the rest of us. Wilczek, a physicist at UC Santa Barbara, and Devine, a science writer with a degree in engineering, do a very good job of combining science with philosophy of science and many dollops of common sense. They write with an engagingly low-keyed style that helps take the curse off the difficulty of their material.

Here is one of their refreshing descriptions of how science actually works:

“In the textbooks, only the successful ideas are recorded. You get the impression that the history of science is a totally progressive, orderly, logical development of ideas. But when you read research at the frontiers of knowledge, you quickly realize it’s not that way at all. Different people, all respected experts, are trying completely different and mutually contradictory approaches. The good ideas, the ones that eventually find their way into textbooks, are out there, all right--but they are out on the shelf surrounded by all kinds of junk, which is packaged by its authors as attractively as possible and, of course, is never clearly labeled ‘junk.’ ”

Operates on Two Levels

The book operates on two levels. It is most successful when it steps back from the details of physics and tells us about the nature of physics. It is least successful when it is explaining those details, which more than once gave me a case of the MEGO’s--my eyes glazeover.

This is not the authors’ fault. Their explanations are as good as one gets, and they make especially good use of analogies and examples. But the material is very hard, and I hope no one is going to give me a test on these subjects.

Still, all is not lost. Even if the details of quantum physics remain a mystery, its puzzling conclusion is clear: “In coming to terms with quantum physics,” the authors write, “we are forced to expand quite drastically our vision of physical reality.”

At the subatomic level, reality is governed by randomness and chance. That much is well known. What’s more, quantum physics tells us that reality does not exist until it is observed, a conclusion that certainly seems to contradict our basic assumptions about the world.

Furthermore, the authors note, “the universe contains a diverging infinity of branching worlds,” which implies that there are alternative realities--an infinity of them--where things have developed differently.

“We have come to enjoy the idea of branching worlds, and we heartily recommend them,” Wilczek and Devine write. “Have you made mistakes in your life? Do you have fantasies about different roads you might have taken? Did you pick the wrong college, marry the wrong person, or choose the wrong profession? Or do you, perhaps, have a wart you don’t like? It is a comfort to think that there are worlds in which each of these things is different.”

Unusual stuff for a book about physics. Yet these are not wild speculations based on mystic who-knows-what. These are the implications of the current state of knowledge, which is itself grounded in experimental data that has been verified many times.

Physics seeks to uncover what is unchanging amid constant change. The physical reality we see before us every day is not constant. The laws behind all of this appear to be the constants, and they are accessible to reason, we think. Modern physics tells us that matter changes, but energy is the basic given.

“The whole idea of science is really to listen to nature, in her own language, as part of a continuing dialogue,” the authors correctly write. “In this dialogue, the scientist plays the role of straight man, asking questions in the form of experiments, but nature’s answers are what the audience has come to hear.”