The Day We Found the Universe - Marcia Bartusiak [2]
It was the astronomical news of the century and yet Hubble, astonishingly, was not present—at this, his moment of triumph. Instead, the staid and respected Princeton University astronomer Henry Norris Russell stood in for Hubble that morning and relayed his findings to the conferees. From all accounts, Hubble was neither sick nor detained by family matters. He might have been put off by the long and wearying cross-country train ride, but the reason for his absence was possibly more idiosyncratic. Hubble, a former legal scholar trained in weighing evidence, was concerned that by the time of the astronomy meeting he hadn't countered every feasible argument against his finding. At his own observatory, in fact, a colleague had gathered the strongest ammunition against his conclusion, evidence Hubble couldn't yet refute. This loose end bothered him immensely. What Hubble craved was an airtight case—no stone unturned, no question left unanswered—before stepping up to the podium himself. Being caught in a scientific error was Hubble's greatest nightmare. Back in California the young astronomer was fretfully asking himself, Could I possibly be wrong?
With the stunning pictures of our resplendent cosmos now so widely circulated, such a part of the routine imagery that surrounds us daily, it's difficult to remember that less than a hundred years ago astronomers' conception of the universe was very different than it is today. There were no quasars, no distant galaxies, no exotic black holes or wildly spinning neutron stars. No one even knew for sure how the Sun could keep generating its tremendous energies over billions of years. What was called “the universe” consisted of a single, disk-shaped collection of stars that cuts a magnificent swath across the celestial sky. With Earth located within this great stellar assembly, we peer outward through the disk and perceive it as a band (much the way a plate looks viewed from its side). Known since ancient times as the Milky Way because of its ghostly white visage, our galaxy a century ago was not just the sole inhabitant of the cosmos. It was the cosmos—a lone, star-filled oasis surrounded by a darkness of unknown depth.
A few voices of dissent could be heard, arguing against this perspective. A growing number of small spiraling clouds were being sighted in the heavens; these faint celestial objects were lurking wherever a telescope gazed away from the Milky Way into deep space. Were these spiral nebulae close to us or were they farther off? No one knew, because at the turn of the twentieth century astronomers didn't yet have the means to determine their distance with assured accuracy. The only thing they could do was speculate. Some looked at these nebulae, shaped like springs unwinding, and thought, “Ah, nearby solar systems in the making.” Others observed the same tiny clouds and imagined them as a host of sister Milky Ways so distant that their stars melded into faint and misty whiteness. That would mean the Milky Way was not special at all but merely one island of stars caught in the midst of a far larger archipelago. But the majority of astronomers rejected this strange—even frightening—concept. That other galaxies existed seemed inconceivable, and so they fiercely clung to what they perceived to be their pivotal place in the cosmos. Nicolaus Copernicus may have moved Earth and its inhabitants from the hub of the solar system in the sixteenth century, but humanity remained comforted by the notion that it retained a privileged position in the very heart of the Milky Way, the sole galaxy. They rested easy knowing they resided in the very center of the universe. There was no hard-and-fast evidence to suggest otherwise.
The Milky Way over the Kitt Peak National Observatory, Arizona (Photo by Michael R. Cole, UrbanImager)
That contentment was shattered, though, as astronomy underwent a spectacular transformation, starting in the waning years of the nineteenth century. “This was an era of extraordinary change in every phase of human life on this planet,” recalled Edwin