The Glass Universe

by Dava Sobel

  In December Shapley sent a draft of Miss Payne’s strange report to Russell, the reigning expert on stellar composition. Russell praised her approach but balked at her results. “It is clearly impossible,” he told her on January 14, 1925, “that hydrogen should be a million times more abundant than the metals.”

  Miss Payne had exercised great care in her methodology. Still, there was no gainsaying an authority of Russell’s stature or experience. Obediently, she tempered her conclusions. When she submitted the write-up in February for publication in the Proceedings of the National Academy of Sciences, she pointed to her “improbably high” percentages of hydrogen and helium, and presumed them “almost certainly not real.” In a field as young as the physical chemistry of stars, anomalous outcomes were no cause for shame. Rather, they indicated pockets of mystery for others to investigate and explain.

  • • •

  SOLON BAILEY OFFICIALLY RETIRED from the Harvard Observatory on February 1, 1925, though he did not stop working there. Now seventy, he went on discovering and studying variable stars in globular clusters, and, at Shapley’s suggestion, started writing an authorized history of the observatory.

  William Pickering also retired in 1925. Like Bailey, William, too, continued to practice astronomy, maintaining the Mandeville observatory at his own expense. He purchased a new telescope after Shapley forced him to relinquish the one he had long kept on loan in Jamaica—the 11-inch refractor donated to Harvard by Mrs. Draper in 1886. As soon as the instrument was back in Cambridge, Shapley rededicated it to stellar spectroscopy and photometry.

  The year 1925 brought belated recognition for Henrietta Leavitt, from an admirer who did not yet know that she had died. “Honoured Miss Leavitt,” began the letter of February 23 from Gösta Mittag-Leffler of the Royal Swedish Academy of Sciences. “What my friend and colleague Professor von Zeipel of Uppsala has told me about your admirable discovery of the empirical law touching the connection between magnitude and period-length for the S. Cephei–variables of the Little Magellan’s Cloud, has impressed me so deeply that I feel seriously inclined to nominate you to the Nobel prize in physics for 1926, although I must confess that my knowledge of the matter is as yet rather incomplete.” The writer, a ferocious advocate for the recognition of women in science, had agitated in 1889 to gain a full professorship at Stockholm University College for the Russian mathematician Sofia Kovalevskaya. In 1903 he successfully pressed the Nobel committee to include Madame Marie Curie in the physics prize being awarded to her husband, Pierre, and their countryman Henri Becquerel, the discoverer of radioactivity.

  Shapley responded to Mittag-Leffler on March 9: “Miss Leavitt’s work on the variable stars in the Magellanic Clouds, which led to the discovery of the relation between period and apparent magnitude, has afforded us a very powerful tool in measuring great stellar distances. To me personally it has also been of highest service, for it was my privilege to interpret the observation by Miss Leavitt, place it on a basis of absolute brightness, and, extending it to the variables of the globular clusters, use it in my measures of the Milky Way. Just recently in Hubble’s measures of the distances of the spiral nebulae, he has been able to use the period-luminosity curve I founded on Miss Leavitt’s work. Much of the time she was engaged at the Harvard Observatory, her efforts had to be devoted to the heavy routine of establishing standard magnitudes upon which later we can base our studies of the galactic system. If she had been free from those necessary chores, I feel sure that Miss Leavitt’s scientific contributions would have been even more brilliant than they were.” Shapley requested permission to share this gratifying tribute from Swedish scientists—confidentially, of course—with Miss Leavitt’s mother and brother.

  Miss Payne often congratulated herself for having avoided the routine work foisted on Miss Leavitt. The spring of 1925 found her in what she called “a kind of ecstasy” throughout the six weeks she spent writing her thesis. In it she described the novel nature of her procedures, laid out the stellar temperature scale she had calibrated, and summarized the abundance of the chemical elements in the stars. Based on her earlier exchanges with Henry Norris Russell, she repeated the caveat regarding the huge ratio of hydrogen and helium. Once again she dismissed their colossal abundance as “almost certainly not real.”

  Just as Pickering had instituted the Harvard Circulars in 1895 to announce Mrs. Fleming’s discovery of her second new star, Nova Carinae, Shapley inaugurated the Harvard Monographs in 1925 to showcase Miss Payne’s thesis. Instead of tucking her opus into a volume of the Annals, where it would have been distributed to subscribing observatories and scientific institutions, Shapley published Stellar Atmospheres in a hardcover edition and offered it for sale at $2.50 per copy. He sent one as a gift to Russell, who shot back his thanks, claiming, “I have eaten it up since I got it yesterday.” Russell declared Miss Payne’s the best doctoral dissertation he had ever read, with the possible exception of Shapley’s own thesis on the orbits of eclipsing binaries. “I am especially impressed,” Russell said, “with the wide grasp of the subject, the clarity of the style, and the value of Miss Payne’s own results.”

  The stunning takeaway from her work was the revelation that all stars closely resembled one another in makeup. The lettered categories in the Draper Catalogue signified differences in temperature, not variations in chemical composition. Henry Draper would have been amazed.

  The hydrogen question, however, still begged for resolution. If the numerous, intense spectral lines of hydrogen did not signify a true abundance, then what did they represent? As the most salient features in many spectra, the hydrogen line patterns had guided the sorting of stars into categories. Spectral shapes had dominated the preparation of the Henry Draper classification, in much the same way as Pickering, in those early days, had assembled his recreational jigsaw puzzles. He always kept the hundreds of pieces facedown, rejecting any hints from the pictures, and fitting the whole together by shape alone. The new view of spectral lines, now imbued with atomic import, made the prominence of hydrogen lines seem incongruous. This new puzzle appealed to Russell, whose leisure pursuits included solving the crosswords printed in newspapers. Russell openly compared the analysis of a complex spectrum to “the solution of a glorified cross-word puzzle.” He was getting at the nuances of spectral spelling and definition by spending more time at Mount Wilson, leading astronomers there to photograph particular stellar spectra for his study, and also cooperating with physicists at the National Bureau of Standards, benefiting from their laboratory spectra of individual elements.

  In an editor’s foreword to Stellar Atmospheres, Shapley reminded potential readers that the application of atomic analysis to astronomy was a field still in its infancy. Miss Payne’s book, he said, showed the general state of the problem but stood open to revision and expansion in the immediate future. Meanwhile, he concluded with pride, “The book has been accepted as a thesis fulfilling the requirement for the degree of Doctor of Philosophy in Radcliffe College.”

  At the same time as Miss Payne earned her doctoral degree, Miss Cannon accumulated two more, honoris causa. Wellesley College wanted to award her a degree on May 29, 1925, the very day she was set to sail for England, so she booked passage on a different ship departing a few days later. “I assure you, dear President Pendleton,” Miss Cannon said in her acceptance, “that to receive such an honor from my Alma Mater, where my first astronomical work was attempted, where Professor Whiting first led my thoughts toward the marvelous and newly developing subject of spectroscopy, will be the greatest incentive to continued effort and increased zeal in the ever-widening fields of my chosen science of astronomy.” In 1921, in contrast, when the University of Groningen invited her to Holland to accept an honorary doctorate in mathematics and astronomy, she had found the timing inconvenient and asked to have the certificate mailed to her. Nor had she been lured away for even one day from the observatory in 1923, when the national League of Women
Voters named her one of the “Twelve Greatest Women Living in America” (along with social worker Jane Addams, suffragette Carrie Chapman Catt, and novelist Edith Wharton).

  Following the Wellesley ceremony, Miss Cannon embarked for England to attend the mid-July general assembly of the International Astronomical Union at Cambridge University. She traveled solo this time, as her sister, sixteen years her senior, was nearing eighty and unable to accompany her. While most of the conference delegates boarded in students’ quarters, Miss Cannon occupied a room in the observatory residence as the special guest of Arthur Stanley Eddington and his sister, Winifred. During the IAU assembly, Harlow Shapley presented an illustrated talk about Miss Cannon’s progress on the Henry Draper Extension. She went next to stay with her friends Herbert and Daisy Turner at Oxford, where she became the first woman in the history of the university to receive an honorary doctor of science degree. Moving on to Greenwich, she took part in Sir Frank and Lady Caroline Dyson’s celebration marking the 250th anniversary of the founding of the Royal Observatory. The royals attended, too, and Miss Cannon saved a clipping that described the queen’s dress as a soft shade of blue, something between hyacinth and hydrangea.

  Miss Payne, who also attended the 1925 astronomy meetings, remained in England for the summer, at home with her mother and sister, Leonora, an aspiring architect. (Her archaeologist brother, Humfry, was away on a dig in Greece.) “I could wish to be back at work,” she wrote Shapley at the end of July; “it took a visit to Cambridge to convince me finally that a return to America is a cause for jubilation rather than resignation, which is a piece of useful business done.” In the fall she rejoined the Harvard Observatory as a postdoctoral fellow. She rented an apartment in Cambridge and registered as a lawful permanent resident of the United States, looking forward to full citizenship and voting rights. Suddenly she found herself strapped for cash. Her previous stipends had been paid at the start of each month, which led her to expect a continuation of the same payment schedule. But now, embarrassed, she realized she must wait for her paycheck till month’s end. To make up the urgent deficit, she pawned her jewelry and her violin.

  CHAPTER THIRTEEN

  The Observatory Pinafore

  CECILIA PAYNE DISCOVERED she loved having a home of her own. Settled in the new apartment, she indulged with pleasure in what she called “the feminine urges” to cook, sew, and entertain. “When one is spending several years in bringing a project to fruition,” she explained, “there is great satisfaction in producing a masterpiece in the kitchen in a couple of hours.”

  Miss Payne had pictured herself “a rebel against the feminine role,” before recognizing that her real rebellion “was against being thought, and treated, as inferior.” She did not at all mind being treated as different—“Of course women are different from men. Their whole outlook and approach are testimony to it”—so long as none of her fellow scientists looked down on her on account of her sex. She faced scant risk of that at the Harvard Observatory, where Annie Jump Cannon could bake a batch of oatmeal cookies for a meeting of the Bond Astronomical Club and then lecture authoritatively to the assembled about her latest findings in spectroscopy.

  Miss Cannon had lately moved with her elder sister, Mrs. Marshall, into a pleasant bungalow on Bond Street, just beyond the border of the observatory grounds. She called the place “Star Cottage,” and it hummed with observatory social life. A motto inscribed in calligraphy in Miss Cannon’s guest book expressed the philosophy, “Since Eve ate apples / Much depends on dinner.” The book’s pages preserved occasions such as “Observatory maidens for supper” (with the signatures of all sixteen invitees), “Edward Fleming to lunch,” and “Tea out of doors. Col. & Mrs. Ames, Adelaide.”

  The observatory community’s paragon of domesticity, however, was surely Martha Shapley. Like the earliest female influences—the wives, sisters, and daughters of the previous directors—Mrs. Shapley had been introduced to astronomy through family ties. Even so, her own skill as a mathematician predated her marriage and exceeded her husband’s abilities in that field. Having helped Harlow with the calculations for his Princeton dissertation, Martha went on to write her own papers for the Astrophysical Journal about the orbits of eclipsing binary stars. In Pasadena, she and Harlow coauthored articles on Cepheids. After the move to Cambridge, despite the duties of caring for four children (she gave birth to the fourth, Lloyd, on June 2, 1923), Mrs. Shapley continued computing the orbital elements for eclipsing binaries. Although she received no salary, her name appeared on numerous Harvard Circulars and Bulletins reporting her contributions. At the same time, she carried on the hospitality tradition of Lizzie Pickering, often inviting visiting scientists to board with the family in the director’s residence adjoining the observatory. Harlow’s convivial style of leadership required Martha to throw frequent parties at which staff members and distinguished guests mingled, played Ping-Pong and charades, and made music. She herself was such an accomplished classical pianist that no one minded when the sounds of her practicing reached the offices. In her role as director’s wife, Mrs. Shapley became widely and affectionately known as “first lady of the Harvard College Observatory.”

  The core group of older computers, originally hired by Pickering, soldiered on in the Brick Building under Shapley’s new management. Louisa Wells had joined the observatory in 1887, Florence Cushman in 1888, Evelyn Leland, Lillian Hodgdon, and Edith Gill in 1889, followed by Edith’s sister, Mabel, in 1892, and Wellesley graduate Ida Woods in 1893.

  Miss Cannon and Miss Maury, also part of the observatory’s old guard, had originally stood out because of their college education in astronomy. By 1925 they were flanked by easily a dozen female students, alumnae, and holders of advanced degrees. Margaret Harwood, for one, had gone out West to earn her master’s years before Shapley bent the Pickering Fellowship to the purpose of graduate study. Adelaide Ames and Cecilia Payne were currently guiding the research of two master’s candidates, Harvia Hastings Wilson from Vassar and Margaret Walton of Swarthmore College. The observatory also embraced a new rank of female guest researcher, in the person of Professor Priscilla Fairfield, Ph.D. Miss Fairfield had earned her doctorate in astronomy in 1921 at the University of California, Berkeley, and since then taught courses in “Celestial Mechanics” and “Measurement and Reduction of Photographic Plates” at Smith College in western Massachusetts. When she first came to work at Harvard in the summer of 1923, she asked for only a modest allowance toward local living expenses. In 1925, in addition to her summer stay, she was making the two-hundred-mile round trip between Northampton and Cambridge on any weekend when rain released her from supervisory duty at Smith’s student observatory.

  The appreciative Shapley won a $500 grant for Miss Fairfield from the Gould Fund of the National Academy of Sciences. “I suggest that you proceed at once in spending the money,” he advised her on November 23, 1925. “May I suggest also that you try to arrange to spend it rather rapidly and efficiently, for I believe that with a little help from here, and a considerable success with the Gould Fund money, Smith College will support the work in a year or so.” Miss Fairfield was comparing the spectra and proper motions of giant and dwarf stars belonging to Draper class M, in order to more clearly define the line distinctions between them. She used the Gould income to pay her student computing assistants thirty cents an hour. “It seems to me,” Shapley added, “that we have the possibility now of building up a useful measuring or computing bureau at Smith, with two objects in view—to get the scientific work done and save one’s soul; to make Smith College the girls’ school where graduate astronomical work is done.” In a handwritten postscript, he conceded that last wish a “funny statement from a Radcliffe professor!”

  Shapley naturally sought to expand his graduate astronomy program to include men as well as women. At first, with only the Pickering Fellowship to offer, he could do nothing more than refer qualified male applicants to opportunities elsewhere. That s
ituation changed in 1926, thanks to the generosity of Visiting Committee chairman George Agassiz. The new Agassiz Fellowship allowed the admission of Frank S. Hogg, from the University of Toronto, as the first seeker of a doctoral degree in astronomy at Harvard (as opposed to Radcliffe) College. Mr. Hogg’s arrival coincided with that of the new Pickering Fellow, Helen B. Sawyer, of Mount Holyoke College. It soon became apparent that Mr. Hogg, who analyzed the spectra of comets, and Miss Sawyer, who studied star clusters, awakened a more than scientific interest in each other. Their courtship overturned a private joke that had long circulated around the observatory: Why is the Brick Building like Heaven? Because there is neither marrying nor giving in marriage there.

  • • •

  AFTER THREE ATTEMPTS to salvage the Arequipa enterprise by decamping to sites in Chile for the cloudy months, John and Dorothy Paraskevopoulos accepted a new Harvard mission. Shapley’s strenuous campaigning on behalf of the observatory had brought in $200,000 from the Rockefeller Foundation’s International Education Board and an equal amount from sources within the university—enough to transplant the Boyden Station at last from Peru to South Africa. In November 1926 the Parases started packing the equipment for the voyage east. They planned to use the Bruce as the premier telescope at Bloemfontein until a larger, more modern one replaced it. Construction of a 60-inch reflector, destined to be the biggest in the Southern Hemisphere, was already under way in Pittsburgh at the firm of J. W. Fecker.

  Pickering had purchased a 60-inch reflecting telescope in 1904, hoping to improve his program of visual photometry. That instrument, however, built by British astronomer Andrew Ainslie Common, behaved poorly, and Pickering, after a few years of tinkering with it, set the 60-inch aside. Shapley scavenged one of the relic’s glass mirrors for resurrection in the new 60-inch.