The Day We Found the Universe - Marcia Bartusiak [23]
With his innovative spirit and success in restoring a once-despised instrument, Keeler pushed reflectors to the forefront of astronomical research. Campbell, who had been carrying out his program to map the motions of the stars, knew that Lick needed a second telescope in the southern hemisphere to complete the observations. Chosen as Keeler's successor to the directorship, he decided to build another 36-inch reflector, similar to the one that Keeler so successfully got working. In 1903 this telescope was erected on a site outside Santiago, Chile, where it was in operation for twenty-five years. The refractor at Lick had cost hundreds of thousands of dollars; Campbell built his Chilean scope for a thrifty $24,000.
In the fall of 1901, just a year after Keeler's death, the Yerkes Observatory assembled a trial reflector of its own in one of its small domes. With a mechanical system far superior to the Crossley, which allowed the mirror to be highly stable, this Yerkes reflector yielded photographs of nebulae that were even better than Keeler had obtained, despite its smaller 24-inch aperture. “The results obtained with the two-foot reflector show that very fine atmospheric conditions are necessary for the best results,” reported the telescope's builder, George Ritchey. “It is interesting to think of the photographic results which could be obtained with a properly mounted great reflector in such a climate and in such atmospheric conditions as prevail in easily accessible parts of our country, notably in California.”
Keeler not only turned reflectors into astronomy's instrument of choice, he inspired astronomers to take a new look at the universe. Was the cosmos defined as simply the Milky Way, or was there more to the universe than met the unmagnified eye? Keeler took a problem previously tackled by amateurs, for the most part—the spiral nebulae—and turned it into a prime concern for professional astronomers. He gave traditional astronomy a good shake at the end of the nineteenth century and in the process reinvigorated a debate that had been going on for centuries. What was the true nature of those irresolvable nebulae—so mysterious, so enthralling—that pervaded the celestial sky? Could the universe possibly be far larger?
Grander Than the Truth
Contemplating a universe of magnificent vastness has not been a recent affair. In the first century B.C., the Roman poet and philosopher Lucretius approached the question with cunning logic: “Let us assume for the moment that the universe is limited,” he posed. “If a man advances so that he is at the very edge of the extreme boundary and hurls a swift spear, do you prefer that this spear, hurled with great force, go whither it was sent and fly far, or do you think that something can stop it and stand in its way?” For Lucretius and a few Greek thinkers before him, it was hard to imagine that an impenetrable cosmic barrier existed. It seemed ludicrous.
But Lucretius's reasoning never flourished. It was overshadowed by the authoritative cosmology espoused by Aristotle in the fourth century B.C. The noted Greek philosopher preferred a motionless Earth poised in the center of a celestial sphere of set dimensions, a concept of such influence that it endured for centuries. Over that time scholars only occasionally reflected on the possibility of a universe significantly bigger. In the sixteenth century, for example, Thomas Digges in England imagined the stars scattered throughout a boundless space, while