The Day We Found the Universe (11 page)

“The hypothesis that the central portion of a nebula like the famous one in
Andromeda
is a single star may be rejected at once,” reported Fath, “unless we wish to modify greatly the commonly accepted ideas as to what constitutes a star.” He suspected the spirals were very remote, as the stars could still not be resolved into individual pinpoints of light, but he had no definitive proof—no slam dunk—to back up that guess. In 1908 there was as yet no way to measure the distance out to Andromeda directly.

As a result, Fath didn't promote his conclusion, perhaps because he was still a lowly graduate student and not in a position of authority to overturn the nebula-as-new-solar-system belief. Or perhaps because Lick Observatory director W. W. Campbell, a careful and conservative man of science, instructed him to downplay his speculations. Whatever the reason, Fath took a particularly cautious tone in the close of his official report. He said that his interpretation “stands or falls” on the question of determining a true distance to a spiral.

The response to Fath's report was like the sound of one hand clapping. Aside from a few outliers, hardly anyone else cared. Fath was soon offered a post at the Mount Wilson Observatory, where he did some follow-up work for a number of years but arrived at no breakthroughs. He eventually settled into a teaching job at Carleton College in Minnesota.

And that's where the matter stood until a man, whom Keeler had once rejected for a Lick graduate fellowship, took over the Crossley reflector in 1910 and continued the groundbreaking work of both Keeler and Fath. And in doing so, Heber Curtis challenged the conventional wisdom with single-minded determination. With great industry and zeal, he took on the problem of the spiral nebulae and made it his own.

Such Is the Progress of
Astronomy in the Wild and Wooly West

A
s Lick Observatory entered its third decade, life on Mount Hamilton continued to be a rustic adventure. Residents hiked the mountain trails, staged amateur theatricals, and read aloud around the roaring fireplace on frosty evenings. As long as the weather was favorable, the telescopes were scheduled for use nearly every night of the year. The lone exception was Christmas Eve, when operations were shut down for the holiday and the graduate students would sneak quietly into the cavernous dome to hang their stockings on the gear of the giant telescope.

There was a new addition to the observatory grounds, a tennis court, where, on Saturday afternoons, as one onlooker described it, “a spectacular performance is kept up, consisting of wild up-bursts of tennis balls, a la Roman candle, followed by hot chases down the canyons.” A molasses jug served as the loving cup for the annual Fourth of July tournament.

Those wanting to go into town often hitched a ride with one of the lucky few, such as Heber Curtis, who owned a car. The astronomer would load people into his Mitchell automobile, nicknamed Elizabeth, making sure to stash a bag of flaxseed in the trunk, so he could pour the seeds into the radiator whenever it started leaking. Pictures of Curtis in his later years, taken after an illness, typically depict a small and stern-looking man. But while he was at Lick, the students knew him as a “wonderfully kind, jolly person, always smiling, always happy.” His genial composure was only broken when he had to sneeze, a feat once described as “remarkable.”

By the 1910s the island-universe theory, dormant for many years, was slowly reemerging among a select group of scientists in both the United States and Europe. These astronomers were specifying that the spirals' sizes and the brightness of their novae only made sense if they were milky ways at great distance. The highly respected English astrophysicist Arthur Eddington was captivated by the vast breadth of this idea; it engaged his theoretical fantasies. “If the spiral nebulae are within the stellar system [the Milky Way], we have no notion what their nature may be. That hypothesis leads to a full stop,” he noted. “If, however, it is assumed that these nebulae are external to the stellar system, that they are in fact systems co-equal with our own, we have at least an hypothesis which can be followed up… [It] opens up to our imagination a truly magnificent vista of system beyond system … in which the great stellar system of hundreds of millions of stars (our galaxy)…would be an insignificant unit.” For Eddington, the heavens just seemed to make more sense viewed from this grander perspective.

The epicenter of this resurgence was located right at the Lick Observatory, where its director, W. W. Campbell, was at last persuaded by the mounting evidence and openly declared that thinking about the spirals as enormous distant bodies was “in best harmony with known facts.” And those facts were largely being gathered by Curtis, one of his most able staff members. Campbell was still focused on his monumental campaign, a virtual assembly line of stellar measurements systematically proceeding from target to target, to catalog the velocities of stars within the Milky Way. The survey was being done in hope that the data would reveal new clues on stellar evolution. It was left to Curtis to get back to the Crossley telescope and revive the observatory's investigation of the spiral nebulae, a program that had not been a top priority since Keeler's death. The compact reflector, however, was still one of the best tools around for imaging and analyzing the hazy celestial clouds.

Curtis, a gifted mechanic, right away made significant improvements to the telescope. First off, he erected a new observing platform that could be raised and lowered by an electric motor, installed a powered dome shutter, and devised a better mechanism for driving the telescope. The mirror had already been remounted in 1904 into a thick metal tube, whose rivets along the side made it resemble a beam on a naval battleship. This telescope remains in operation, now searching for extrasolar planets. It's possibly the oldest reflecting telescope still in use for professional research.

Heber Curtis standing by the renovated Crossley telescope
(Mary Lea Shane Archives of the Lick Observatory, University
Library, University of California-Santa Cruz)

When Curtis rekindled Keeler's pursuit of the spiral nebulae, the island-universe theory was regarded as just a good guess, an intuitive suspicion. Curtis was after more concrete proof. He started to dig deeper into the problem, in the same way that Keeler would likely have proceeded. But Keeler had a mere two years to work with the Crossley before his death; Curtis, fortunately, had more time, which allowed him to extend astronomy's knowledge of the spirals throughout the 1910s. This celestial quest became, in the words of a fellow astronomer, Curtis's “magnum opus.”

No one was more surprised perhaps at the zigs and zags in Curtis's career path than Heber Doust Curtis himself, who went to college at the University of Michigan in Ann Arbor, at the same time that Campbell happened to be teaching there. But their paths never crossed, for Curtis was a dedicated student of the ancient languages—Latin, Greek, Hebrew, Sanskrit, and Assyrian—earning first a bachelor's degree, then a master's. At this stage, Curtis voiced no interest whatsoever in science and never set foot inside an observatory. After teaching high school briefly in Detroit, he moved to California in 1894 to become a professor of Latin and Greek at Napa College, a small institution north of San Francisco. Curtis seemed destined for a life of quiet scholarship in the classics, until he came upon a small telescope at the college and on an impulse began to tinker with it.

His tiny college later merged in 1896 with the University of the Pacific, situated in the San Jose area, and he moved there, opportunely within the shadow of Lick Observatory. He continued his astronomical activities and got so caught up in his newfound hobby—and so adept at observing—that he was chosen to teach mathematics and astronomy at the small college. He was even able to spend some time on Mount Hamilton during the summers of 1897 and 1898 as a special student. The experience convinced him that he wanted to make astronomy his life's work. He hoped to continue at the Lick Observatory as a graduate student, but his inadequate preparation in science put up roadblocks. Keeler, Lick's director at the time, was looking for someone more professionally skilled in spectroscopy. Curtis was finally offered a fellowship at the University of Virginia, where for his PhD he reluctantly focused on a more mathematical topic, celestial mechanics, although along the way he made sure to get as much instrumental experience as possible. It was a risky move. He was resigning from a college professorship to start anew as a student in a field in which he had no prior training—and with a growing family to support as well.

Serendipity offered an assist. Just as Curtis was headed east in 1900 to begin his doctoral studies, Lick astronomers William Campbell and Charles Perrine were traveling to Georgia to scrutinize a solar eclipse, whose shadow was scheduled to cut across the southeastern United States. Curtis signed on as a helper, saying he was “ready and glad to be put at anything from a shovel up.” Given this opportunity, he proved to the Lick men that he could handle a telescope and spectrograph as if he had been using them all his life. Campbell took notice. As soon as Curtis finished his degree at Virginia in 1902, Campbell, by then Lick's director, hired him on as an assistant. To Curtis, having lived on a small mountain in Virginia was simply good training for a life on Mount Hamilton, where kids hunted rattlesnakes for fun in the summertime.

Curtis arrived at Lick covered in thick yellow dust from the long stagecoach ride, raring to begin his research straightaway. For the first few years, he focused on traditional Lick specialties, such as measuring stellar velocities, computing the orbits of binary stars, and going on solar-eclipse expeditions. Life was fairly routine, until one memorable April morning in 1906 when the mountain experienced a minor temblor. Damage was minimal at the observatory—a few coal-oil lamps overturned, loosened bricks on some of the buildings—but looking toward San Francisco, Lick residents saw an enormous tower of black smoke. They didn't realize how serious the disaster was until noon, when the daily stage from San Jose, which normally ran like clockwork, never showed up. By evening the astronomers turned Lick's 12-inch telescope completely horizontal and aimed it toward the Golden Gate, the strait connecting San Francisco Bay to the Pacific Ocean. Through the scope they saw three miles of fire-front, burning fiercely. “And, naturally, the lens inverted everything, so we saw buildings fall up and flames sweep down—which was a weird, weird sight…. It reminded me of… Dante's
Inferno,”
said Douglas Aitken, who had lived on the mountain at the time as a young boy.

Curtis missed all the excitement because two months earlier he had arrived in Chile to head up Lick's southern station on the summit of San Cristobal, on the outskirts of Santiago. With him were his mother, wife, and three small children. After a few years they became so comfortably settled in Chile that they contemplated an extended stay, having become fluent in Spanish and grown fond of the South American lifestyle. “Queer how completely we seem to have taken root here,” noted Curtis. But in 1909 Curtis received an unexpected invitation to return to Lick, not as an assistant or associate, but as a senior astronomer. Short on staff, the observatory needed an experienced hand to work with the Crossley reflector. In accepting the post, Curtis became Keeler's anointed successor, the next in line to tackle the mystery of the spiral nebulae.

Curtis first spent time getting to know the Crossley's strengths and weaknesses: What were the faintest stars it could photograph? How many hours of exposure were required? He had the good fortune to start his new venture just as a famous celestial visitor, Halley's Comet, visibly reappeared in the skies in 1910, as it did every seventy-six or so years, providing a superb target to test out the Crossley's photographic abilities. The comet this time passed relatively close to Earth, creating quite a stir throughout the world, so by the time it completely disappeared from telescopic sight in 1911, the Crossley and other Lick telescopes had taken nearly four hundred pictures of its spectacular passage.