The Day We Found the Universe - Marcia Bartusiak [67]
But it was yeoman's work, painstaking routines that took four years to complete. Shapley was securing the distance to every Milky Way globular cluster known at the time, sixty-nine in all. With the assistance of Edison Hoge, he took some three hundred photographs. Some exposures were only ten seconds in length, but others lasted up to two hours. Most took minutes. Afterward there was the brutal labor at the work-table analyzing what the images revealed. By 1917 he was writing a colleague that “the work on clusters goes on monotonously—monotonous as far as labor is concerned, but the results are continual pleasure. Give me time enough and I shall get something out of the problem yet.” By then the war was on, but Shapley didn't sign up. He claimed that Hale had convinced him to stay at his job.
Some of the globular clusters (circled) surrounding the Milky Way
(Harvard College Observatory, courtesy of AIP Emilio Segrè Visual Archives)
Shapley didn't particularly enjoy his nights alone with the stars. What drove him back to the telescope month after month were his findings. With the first hint of dawn in the east, as the dome slit slowly closed with a noisome squeal, nearby coyotes would answer in kind with a serenade of high-pitched howls. At night's end, he and the other astronomers would walk back to the Monastery, sometimes whistling a merry tune if the viewing went well and forgetting that they might be disturbing the daytime observers—the solar astronomers—who were still fast asleep. Once in bed themselves, though, the nighttime observers could easily be wakened by the stirrings of the daytime crew. Both sides were together at noontime lunch, which offered the opportunity to settle any squabbles.
Shapley was curious about nearly everything that came his way when on the mountain. “The most unwarranted fun of all comes from bugs,” he wrote a colleague while trapped in a snowstorm on Mount Wilson. “Not that I know much about them, but I am so interested that I would like to turn biologist.” In a way, he did. He began to study the travels of ants around the observatory, noticing that the higher the temperature, the quicker their pace. One species ran fifteen times faster once the Sun heated the insects by an additional 30°C. As he put it, he had discovered the “thermokinetics of ants.” Setting up “speed traps” to gauge the ants' pace precisely, he boasted he could estimate the day's temperature to within one degree by their perambulations. “Another method is to read your thermometer,” he wryly added. His findings were published in scientific journals. For further rest and relaxation, he and his wife climbed all the nearby mountains—little and big—collected plants, and killed any rattlesnakes that came their way.
Between 1916 and 1919 Shapley published his growing body of data on the globular clusters in an extended series of papers, collectively titled “Studies Based on the Colors and Magnitudes in Stellar Clusters.” Each article progressively added another piece to the puzzle. Shapley was taking his reporting skills to a new beat. And in carrying out this endeavor he was ultimately forced to alter his original mental picture of the universe. It began to dawn on Shapley that the Milky Way was far larger than anyone had previously conceived. The first hints arrived when he estimated that some well-known star clusters within the