The Day We Found the Universe - Marcia Bartusiak [111]
Hubble was gaining more confidence in his findings. And Shapley, in response to the growing body of evidence, at last saw the scientific handwriting on the wall. He cried uncle, acquiescing speedily and graciously. While visiting Wood's Hole in Massachusetts with his family for a summer holiday, helping dredge starfish at one point off Martha's Vineyard, Shapley briefly paused in his frolicking to respond to Hubble's August letter. He described the new results as “exciting.”
“What tremendous luck you are having,” he wrote. “I do not know whether I am sorry or glad to see this break in the nebular problem. Perhaps both.” Shapley knew his change of heart now meant abandoning his Big Galaxy model of the universe and questioning the spiral rotation measurements of van Maanen, his good friend. He regretted that this had to happen, but Shapley was also relieved to have something definite about the spirals at last come to light. Once proven wrong, the Harvard Observatory director didn't look back and quickly adjusted to the new cosmic landscape, soon becoming its most boisterous promoter.
By the end of 1924 Hubble was finally starting to write a preliminary draft of his findings for the Proceedings of the National Academy of Sciences. He was dipping his toe into the proverbial water, but he was hardly leaping into the drink. As Hubble wrote Slipher on December 20, he was still hugely frustrated by van Maanen's contradictory observations on the spiral rotations. If the spiral nebulae truly resided in distant space, at least a million light-years away, no astronomer could possibly see them rotate in a matter of years. How could he make that conflict go away? “I am wasting a good deal of time investigating the possibilities of magnitude effect in van Maanen's measures. The suggestion is very strong among the comparison stars of M33 and M81 but I can not carry it through some of the others,” he told Slipher. Had he truly discerned the source of van Maanen's error? Were the apparent magnitudes of the spiral stars that van Maanen picked out to make his measurements differing from plate to plate because observing conditions were dissimilar or the star was imaged on a different part of the plate? That could make it tricky to pinpoint each star's exact center, which would lead him to mistakenly measure the stars as moving, making it seem as if the entire spiral were rotating. Or was it something else? Before publishing anything, Hubble wanted to confront and overturn each and every result in van Maanen's work that was at odds with his discovery. He closed his letter to Slipher saying that he would not be attending the latest meeting of the astronomical society, starting in ten days in Washington, D.C.
Word of Hubble's discovery was still spreading like wildfire through the astronomical community. Though not yet official, the news even made it into the New York Times. Readers turning to page 6 on November 23, 1924, saw this headline (complete with misspelling): “Finds Spiral Nebulae Are Stellar Systems—Dr. Hubbell Confirms View That They Are ‘Island Universes’ Similar to Our Own.” With Hubble revealing that the Andromeda and other nebulae were at least a million light-years distant, reported the newspaper, then “we are observing them by light which left them in the Pliocene age upon the earth.”
Yet Hubble continued to stall, unwilling to rush his finding into the scientific literature. Though the island-universe theory had been gaining supporters, others persisted in regarding the spiral nebulae as minor entities. But the scent of resolution was in the air. At the December 1924 meeting of the British Astronomical Association, Peter Doig, a prominent figure in British amateur astronomy, presented a paper on the spiral nebulae that cautioned