The Glass Universe: The Hidden History of the Women Who Took the Measure of the Stars. Дава Собел

Чтение книги онлайн.

СКАЧАТЬ star at a time. Each spectrum imaged in this manner spread over an expanse of at least four inches, even before enlarging. The gratifying increase in detail gave Miss Maury much to ponder as she examined the plates under a microscope. In the same blue-violet region of Vega’s spectrum where her uncle had photographed four lines in 1879—and ten in 1882—she now counted more than one hundred.

      Along with measuring the distances between the lines and converting them to wavelengths, she was expected to classify each spectrum according to Mrs. Fleming’s criteria. But Miss Maury had so much more detail to work with that she could not confine her impressions to those parameters. Some of the lines she looked at were not simply thick or intense, but also hazy or fluted or otherwise noteworthy. Such nuances surely deserved attention, for they might illustrate as yet unsuspected conditions in the stars.

      • • •

      WHEN HARVARD’S SECOND MOUNTAIN reconnaissance headed West in November 1888, Pickering opted out. He could not possibly afford enough time away from the observatory to fulfill the mission’s ambitious itinerary, which was to begin site testing near Pasadena, California, and continue among the Andes in Chile and Peru. He put his brother, William, in charge. While in California, the team would also visit the Sacramento Valley to observe and photograph the total solar eclipse of January 1, 1889.

      Ordinarily, Pickering did not support eclipse expeditions, on practical grounds. He deemed the expense too high, given the high risk of failure. An ill-placed cloud during the scant moments of totality could scotch the whole enterprise (as he had learned firsthand when he went to Spain with former director Winlock for the eclipse of December 22, 1870). But if, as in the present case, the path of totality nearly crossed the path of exploration for the new Boyden Station, Pickering would not object to a small detour.

      Favorable weather smiled on the observers for the New Year’s Day eclipse. Excitement at the rare sight, however, shook the astronomers and the large crowd of onlookers alike. At the start of totality, the spectators started to yell. The noise drowned out William’s call to the person counting out the seconds, and his struggle to make himself heard caused him to take fewer pictures than he intended. He also forgot to remove the lens cap from the spectroscope.

      From his disappointment in Sacramento, William went south to Mount Wilson, where he and a few assistants were to test atmospheric conditions by observing for several months with a 13-inch telescope they brought along for that purpose. At the same time, the other half of the team departed for South America. In Pickering’s grand scheme, two mountain observatories were better than one. A California aerie would improve on the work done at Cambridge, while an additional satellite station in the Southern Hemisphere would widen Harvard’s field of view to encompass the entire sky.

      Pickering entrusted control of the South America venture to Solon I. Bailey, age thirty-four, who had joined the observatory staff as an unpaid assistant two years earlier and quickly proven himself deserving of a salary. Like Pickering, Bailey had a younger brother with a talent for photography, and so, with Pickering’s blessing, Solon appointed Marshall Bailey as his second-in-command, and planned to meet him in Panama after the eclipse. Facing a trip expected to last two full years, Solon took along his wife, Ruth, and their three-year-old son, Irving.

      The February 1889 voyage aboard the San Jose of the Pacific Mail gave Bailey occasion to practice his Spanish with several fellow passengers, whose names he recorded in his journal. On deck, he enjoyed watching Venus sink into the sea after sunset, “plainly seen till she touched the water.” In the predawn February sky, he sighted the Southern Cross for the first time. Bailey had loved the stars since his boyhood in New Hampshire, where he witnessed the great natural fireworks of the 1866 Leonid meteor shower. Now he would meet a sky’s worth of new constellations, which prospect inured him to whatever hardships lay ahead.

      The bulk of the Andes expedition supplies—everything from photographic plates to prefabricated buildings—traveled with Marshall from New York to the Isthmus of Panama, then overland, past the recently aborted French canal effort and the graveyards of fever victims to another ship bound for Callao, near Lima.

      The party rode the Oroya Railroad twenty miles east from Lima to Chosica, and from there the Bailey brothers ascended on foot and by mule to elevations of 10,000 feet or more. Their native guides nursed them through bouts of altitude sickness with an effective local remedy, namely the odor of bruised garlic. No particular peak impressed Bailey as ideal, but he needed to seize the good weather of the dry season, and so settled for a nameless mountain with the least obstructed view. It stood just over 6,500 feet high, barely accessible by a path that switchbacked up and around for eight miles. The Baileys labored alongside a dozen locals for three weeks to improve the route from the hotel in Chosica to the site, and then helped drag eighty loads of equipment up that road to the makeshift observatory. When the family moved in on May 8 along with their Peruvian assistant, two servants, cats, dogs, goats, and poultry, their only neighbors were centipedes, fleas, scorpions, and the occasional condor. They relied on a muleteer for daily supplies of water and food.

      The Baileys assessed the brightness of the southern stars with the same meridian photometer that Pickering had used in Cambridge, in order to make their observations exactly comparable to his. Similarly, they photographed the southern stellar spectra for the Henry Draper Memorial with the selfsame 8-inch-aperture Bache telescope that had seen nightly duty through the project’s first two years. Mrs. Draper replaced the original workhorse at Harvard with another of the same specifications.

      Solon Bailey stayed in touch with Pickering as regularly as the mails allowed. When he shipped the first two cases of glass plates to Cambridge, he said they came from an as yet unnamed place that he would like to call Mount Pickering.

      “Mt. Pickering might wait,” the director wrote back on August 4, 1889, “until I have done as good work as you have on a Peruvian mountain.” With local approval, the Baileys christened the site Mount Harvard instead.

      When the October onset of the rainy season halted work on Mount Harvard, Bailey moved his wife and son to Lima, then set off with his brother to scout better locations for a permanent base. It took them four months to find a place that met their requirements, on the high desert plain near the town of Arequipa. At 8,000 feet, the air was clear, dry, and steady, and the nearby volcano, El Misti, was nearly extinct.

      • • •

      WHILE THE BAILEYS EXPLORED PERU, Edward Pickering became engrossed with the odd spectrum of a star called Mizar in the handle of the Big Dipper. The star had first drawn his surprised attention on a Draper Memorial photograph taken March 29, 1887, which showed an unprecedented doubling of the spectrum’s K line. (Although Fraunhofer’s original lettering ended at I, later researchers added other labels.) Soon after Pickering shared the unusual news with Mrs. Draper, the strange effect vanished as suddenly as it had appeared. Subsequent images of Mizar’s spectrum failed to recover the double K line, but still Pickering kept watching for its return. On January 7, 1889, Miss Maury saw it, too. Pickering, who rarely invoked an exclamation point, wrote Mrs. Draper, “Now it seems nearly certain that it is sometimes double and sometimes single!” Although, he quickly added, “It is hard to say what this means.” He suspected that Mizar, also known as Zeta Ursae Majoris, might turn out to be two stars with virtually identical spectra, too closely aligned to be seen separately, even through a big telescope.

      Miss Maury could picture the Mizar pair as two wary combatants, circling each other while vying for advantage. Her distant vantage point made it difficult to distinguish the two separate bodies—impossible, in fact, when either one stood in front of the other along her line of sight. But Mizar’s twin fighters were emitting light. As they revolved, their relative motions slightly altered the light’s frequency: the approaching starlight shifted slightly toward the blue end of the spectrum, the receding starlight toward the red. Those shifts added up to the small K-line separation that created the doubling effect.

СКАЧАТЬ