The Day We Found the Universe - Marcia Bartusiak [70]
“While I cannot pretend to have anticipated the view of the stellar system that now seems to be emerging,” responded Eddington, “I do not feel any objection to it either.” This was a confidence booster for Shapley, who was still essentially a rookie in astronomical circles and assuredly grateful for support from such a renowned figure.
Shapley didn't forget to give his boss, George Ellery Hale, then out of town on stressful war business, advance notice as well. “May I impose upon your time for a little while, with an off-hand talk about my astronomical work—divert your attention from earthly troubles to heavenly affairs?” wrote Shapley. The young staff astronomer hardly knew where to begin and for brevity's sake he cautioned Hale that he was leaving out the “probablies, perhapses, maybes, apparentlies, and other such necessary weaknesses in scientific exposition…. So my assumed surety … is neither over-confidence nor a whistling in the dark, but an agreement between us.”
True to character, Shapley fashioned one of his ubiquitous tall tales to present his case to Hale: “The first man, away back in the later Pliocene, who knocked out a hairy elephant with his club, or saw his pretty reflection, or received a compliment, became suddenly conceited (it was a mutation) and there immediately evolved the first reflective thought in the world. It was: ‘I am the center of the Universe!’ Whereupon he took himself a wife, transmitted this bigotry of his germplasm, and through hundreds of thousands of years the same thought without much alteration has been our heritage.” And now, he assured Hale, he would furnish the remainder of the story.
Shapley reminded Hale that he was determining the distances to all the globular clusters then known and was getting ready to publish a series of papers announcing the results: twenty pages of tables, nearly a dozen figures, and around a hundred pages of text in all. For Hale, Shapley summarized his results in three, single-spaced typed pages. The bottom line, he said, was this: The Milky Way is huge, some 300,000 light-years in width, and the Sun is far away from the hub. “Start a messenger on a light-wave down the main highway from the center,” wrote Shapley, and he'd end up at Earth about sixty-five thousand years later. Moreover, he said, “there is no plurality of universes… The galaxy is fundamental in what we call the universe.” True to his impetuous nature, Shapley threw caution to the wind. The Milky Way was now so big, he figured, it had to be the dominant feature of the universe.
When the Milky Way was thought to span only 10,000 or 30,000 light-years, it was easier to think of the spiral nebulae as separate galaxies. But everything changed when Shapley claimed the Milky Way was far larger. If the Andromeda nebula was also a galaxy and with similar dimensions to the Milky Way, its distance would have to be farther out than anyone anticipated to appear as it did on the sky. And that meant that the novae that lighted up within Andromeda's disk were even more luminous than any known physical law could possibly explain. Within a matter of months, Shapley made a complete about-face regarding the spiral nebulae. Once a believer in island universes, Shapley now considered it more reasonable to assume that Andromeda and the other spirals were simply closer: either nestled cozily inside our galactic borders or situated just outside, as smaller outlying colonies. They were no longer the Milky Way's equal in grandeur and power but mere appendages. He even speculated at one point that they might be blobs of nebular material somehow being repelled by the Milky Way at high velocities, perhaps due to radiation pressure or electrostatic forces. As our galaxy travels through space, surmised Shapley, it might be driving “the nearby spirals to either side