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BOOK REVIEWS

prove that there was a universe more vast Hubble Wouldn’t Be and varied beyond our Milky Way. Before her work allowed for a definite Hubble without Her method of measurement, there was a GREG MARTINEZ pitched battle between those who advo- cated an enormous universe with those Miss Leavitt’s Stars: The Untold Story of the Woman Who who posited an idea of a smaller, more Discovered How to Measure the Universe. By George compact universe with little or nothing Johnson. New York: Atlas Books, W.W. Norton & beyond our galaxy. Company, 2005. ISBN 0-393-05128-5. 162 pp. After Hubble’s brilliant application Hardcover, $22.95. of Leavitt’s Law to discover galaxies and stars millions of light-years away, astron- n the preface to his short biography nickel more than the other members of omy eventually went on to measure an of Henrietta Swan Leavitt, the sixth “Pickering’s harem,” a group of women expanding universe, a discovery that Iin the Great Discoveries series pub- who did the extremely precise and extra- inevitably led to the Big Bang theory. It lished by W.W. Norton, George ordinarily tedious task of measuring and is difficult to overstate the importance Johnson admits to the incompleteness cataloging the brightness, color, and posi- of her discovery to modern astronomy. of the portrait he paints of this largely tion of each star in the tens of thousands Johnson weaves an absorbing tapestry forgotten giant of twentieth-century of glass photographic plates that Harvard of the colorful personalities and events in astronomy. “Henrietta Swan Leavitt astronomers were collecting. which Miss Leavitt played such an The task of organizing these repeti- deserves a proper biography,” he writes. important role. What disappoints, tive and fragile plates was left to women, “She will probably never get one, so inevitably, is how little of her there is in not only because of their supposed faint is the trail she left behind.” this story. We learn that she suffered strength of concentration but because Because she left behind only scant recurring bouts of long unnamed ill- they were cheap labor. There was never letters, no personal diary or journal, no nesses that would take her away from her any intention of allowing them to work memoir, and only two known pho- beloved variables for years at a stretch. in any capacity that might engage them tographs, this neglect of Miss Leavitt One such stretch, shortly before her hir- in theory, or even the use of imagination seems less an outcome of the marginal- ing at Harvard, led to near total deafness. or insight. Leavitt, through her demon- ization of women in science than the What might otherwise have been a dis- strated brilliance, rose above these inevitable result of her starving biogra- ability had little impact on a person of phers of the materials they need to func- pointless limitations to produce an strong will and even stronger intelli- tion. Johnson writes that he had insight into the relative luminosity of a gence, and was hardly a problem for a intended to use her as a device to begin particular class of variable star called person whose primary job duty was to sit his story of the incremental moves made Cepheid variables. silently, focusing on glass photographic by astronomers to discover and measure Her obsession with these bodies, plates. She lost more work time due to the cosmos beyond the Milky Way. which vary in brightness in periods last- repeated absences to care for other ill and (Indeed, the promotional materials that ing from days to weeks, led to a revolu- dying relatives. Miss Leavitt succumbed announced the launching of this series tionary insight into the measurement of to her final illness, stomach cancer, in projected this volume as a biography of the universe. With the huge number of 1921, at the age of fifty-two. Edwin Hubble.) But Johnson found images available to her, she was able to If she chafed under the cramped role that she was so pivotal to the story of the trace the patterns that revealed that the measurement of the universe that he had rate of variation of a Cepheid was an she was allowed to play in the Harvard to make her the focus of his tale. accurate measure of its actual brightness. Observatory, we have no details of her It is a focus she deserves. She was By comparing the apparent brightness struggles. What it was like for her, pos- hired by the director of the Harvard of these stars against their actual lumi- sessed of such a brilliant mind and College Observatory, Edward Pickering, nosity, one could work out the distance accomplishing the kind of breakthrough in 1902, after seven years of volunteer to any Cepheid variable. This yardstick, that countless scientists have hoped for work at the observatory. Her appoint- called the Cepheid variable period-lumi- but never achieved, was apparently ment to the permanent staff brought her nosity relationship, or Henrietta’s Law, never shared with anyone. In spite of the plum salary of thirty cents an hour, a allowed for the measurement of the dis- Johnson’s excellent effort, she remains a tances between other stars and objects. cipher. But the enormous body of Greg Martinez lives and writes in The significance of this was breath- knowledge she granted us with her dis- Gainesville, Florida. He can be reached at taking. With Miss Leavitt’s yardstick, covery is a fitting epitaph. She probably [email protected]. astronomers like Edwin Hubble could would have wanted it that way.

SKEPTICAL INQUIRER May / June 2006 63