American Scientist

The Discoveries: The Great Breakthroughs in 20th-century Science, Including the Original Papers. Alan Lightman. xviii + 553 pp. Pantheon, 2005. $32.50.

Why is it that Hamlet and Moby Dick are universally recognized as great works of art, whereas the original scientific papers of luminaries such as Albert Einstein or Barbara McClintock—containing creative and imaginative leaps just as profound—are seldom read, even by scientists? Troubled by this incongruity, physicist, novelist and science writer Alan Lightman has collected 25 of the most important scientific publications of the last century in a volume titled The Discoveries. Ranging from Max Planck's introduction of quantum discontinuity into black-body radiation (1900) to Paul Berg's pioneering recombinant DNA techniques (1972), the discoveries marked by these papers represent exhilarating forays into the unknown. Each paper is accompanied by a short essay by Lightman describing the historical context and the scientists' inspirations and motivations.

Great scientific papers, Lightman insists throughout, are works of art:

Like poetry, these papers have their internal rhythms, their images, their beautiful crystallizations, their sometimes fleeting truths. . . . In these papers, we see enormously gifted human beings grappling with the nature of the world.

The Discoveries is thus far more than a lineup of 20th-century science's "greatest hits." It is an attempt to show that reading formal scientific literature can offer a window into the minds of great scientists. Lightman certainly has a point: Great scientific work of the past is rarely encountered in its original form, whether by professional scientists, their students or the educated public. Retrospective accounts of great discoveries hardly ever present a window onto the scientific imagination, or into the individual thinking style of the scientist herself.

The trouble is, neither do most scientific papers. Consider the contrast between Otto Loewi's matter-of-fact 1921 report on chemical neurotransmitters and the feverish, dream-inspired, late-night activity that led to their discovery. Or James Watson and Francis Crick's dry 1953 announcement in Nature of their model for the structure of DNA, compared with the sensational rivalries and ruthless race to the finish portrayed in Watson's memoir, The Double Helix. The conventions of scientific literature tend to obscure what Lightman's essays place in the foreground: the "prejudices, passions, and personal judgments" that propel scientists to discovery.

The essays bring each discovery to life as a dramatic human event, but they do little to inspire close readings of the original publications. Many of the papers will remain incomprehensible to the nonspecialist, even with Lightman's guidance. This is unsurprising, because most scientific publications—whether groundbreaking or routine—are expressly written for specialists. They are not meant to be easily grasped even by scientists outside the discipline or subdiscipline of the author. Thus the short and densely mathematical paper of 1967 in which Steven Weinberg presents his brilliant unified theory of weak and electromagnetic interactions may seem jarringly impenetrable next to Lightman's elegant account of the symmetry principles underlying its argument. (Weinberg himself is known for his exceptionally well-written books on physics for a general audience.) Rather than elucidating the internal rhythm and style of the historical papers, Lightman's essays may tempt the general reader to skip them altogether.

The essays about the papers form the real backbone of the book and take up two-thirds of its 509 pages. As one might expect, Lightman is most masterful on topics in physics. At his best, he seamlessly weaves technical material and philosophical reflections into his gripping accounts of the flawed but brilliant men and women who drive scientific change. Alexander Fleming's discovery of penicillin, Edwin Hubble's proof of the expansion of the universe and Weinberg's development of unified field theory are all beautifully narrated. For context Lightman draws judiciously on numerous biographies and histories of science. At times, though, he goes against established consensus in the historical literature. He has Planck committed in 1900 to the position that "energy has a granularity," even though many historians argue that Planck was uncomfortable with taking quantization that far. And he portrays Albert Michelson and Edward Morley's attempt to measure the properties of the ether as a crucial experiment in the history of relativity—a myth debunked by the eminent Einstein scholar Gerald Holton decades ago.

The Discoveries provides a compelling snapshot of a scientific century teeming with big ideas. Some readers will undoubtedly quibble over the omission of personal favorites such as general relativity or continental drift. But the fact is that Lightman has compiled an array of profoundly original and influential discoveries. We may have to look elsewhere, however, to understand the elusive creative processes of discovery. Consider the brilliant and reclusive McClintock, whose description of her own dawning comprehension of transposons (or "jumping genes") Lightman wisely allows to speak for itself:

When you suddenly see the problem, something happens—you have the answer before you are able to put it into words. It is all done subconsciously. This has happened too many times to me, and I know when to take it seriously. I'm so absolutely sure. I don't talk about it, I don't have to tell anybody about it, I'm just sure this is it.

Lightman's map of 20th-century science beautifully conveys the human drama of discovery but leaves its imaginative unfolding as mysterious as ever.