Quantum Generations: A History of Physics in the Twentieth Century (review)

Quantum Generations: A History of Physics in the Twentieth Century. By Helge Kragh. Princeton, N.J.: Princeton University Press, 1999. Pp. xiv+494. $29.95.

Physics, above all other branches of learning, underpins the microelectronics, the radiations of diverse wavelengths, and the molecular engineering that guide our life today, and in Quantum Generations Helge Kragh has provided a comprehensive and accessible history of physics in the twentieth century. Over the past thirty years, studies of late-nineteenth-century and twentieth-century physics have set the standard for scholarship in the history of science with respect to methodology, effective use of source material, elaboration of explanatory theses, and prose style. Kragh has provided the best synthesis to date, displaying clear insight, judicious selection of primary material (both published and unpublished), and wide reading in the extensive secondary literature.

The narrative is a history of ideas with two significant departures. First, Kragh often centers his discussion on quantitative trends, from employment statistics and production of Ph.D.'s to funding throughput and literature output. As a result, his generalizations achieve a cogency often lacking in intellectual history. Second, Kragh seeks to probe national competition in research by identifying where physicists worked. In the first third of the century, physics flourished above all in Germany; after that, in the United States. In the middle part of the century, military funding overwhelmingly supported physical research. In the first half of the century, physics suffered an eclipse in France; in the second third, it developed significant strengths in Japan and Italy. Across the middle of the century, Kragh identifies a style for American physics and national differences in cosmology.

Kragh intentionally neglects atmospheric physics and geophysics, and he restricts his discussion to events in Europe, the United States, and Japan. But the prose, as well as the analysis, is skewed against other contributors and contributions. For example, more than thirty Nobel laureates in physics through 1998, listed in table 28.3, do not find a place in the book's index, and about half of the absentees claim a nationality other than Germany or the United States. Some readers may be troubled by the national tags: the Braggs count only for England, and Born counts only for Germany; Einstein counts only for Switzerland; Raman counts for India, but Marie Curie does not count for Poland; Chandrasekhar counts only for India, while Homi Bhabha "was from India, but worked in England" (p. 202). Other readers will find it inelegant that elite, Ivy League institutions turn up so frequently. Even the University of Rochester is identified for Robert Marshak and his two-meson theory (p. 203). But farther down the page, when a seminal contribution from Université de Montréal is at issue, we learn only about "the Italian physicist Bruno Pontecorvo, at the time working in Canada (he would later emigrate to the Soviet Union)." The next page refers to the "Brazilian physicist Cesare Lattes"; three pages along comes the semiclassical quantum theory in 1952 of David Bohm, "the young American physicist." George Gamow, who garners about as much space in the index as Rutherford or Planck, is bereft of nationality and institution. In these pages alone, physics extends from Montréal to Boulder to Rio de Janeiro and São Paulo.

One theme in Quantum Generations concerns the insensitivity of disciplinary norms in physics to cultural variation: The early history of quantum electrodynamics (notably the contributions of American and Japanese physicists) "together with other examples from the history of science . . . supports the hypothesis that the cognitive content of physics does not depend significantly on the sociocultural environment" (p. 335). A reader will find, however, that the evidence presented does allow for just such dependence. For example, Kragh brusquely discounts Paul Forman's persuasive analysis of the way that Weimar physicists assimilated an antirational and acausal zeitgeist by uncritically embracing Heisenberg's principle of indeterminacy. And although evidence...