The Day We Found the Universe - Marcia Bartusiak [90]
The two were feeling quite cocky. At this stage, van Maanen at last made it publicly known, in the Proceedings of the National Academy of Sciences, that his observations “raise a strong objection to the ‘island-universe’ hypothesis.” If M33, the prominent spiral in the Triangulum constellation, for example, were several million light-years distant, he pointed out, the motions he detected would represent velocities near the speed of light, “which, obviously, are extremely improbable…[and] afford a most important argument against the view that these nebulae are systems comparable with our galaxy.”
But this declaration was hardly a resolution to the Great Debate. While Shapley and van Maanen were smugly celebrating, Knut Lundmark was visiting the Lick Observatory, using the Crossley reflector to gather the extremely faint light of M33. It was a difficult task, requiring extremely long exposures, one totaling thirty hours collected over four nights. Lundmark eventually saw that the light from the nebula's spiral arms resembled nothing less than the light of ordinary stars. Where other astronomers had seen a fuzzy patch in a spiral arm and called it a “nebulous star,” Lundmark pondered whether each mistlike spot was instead “a great number of very distant stars…crowded together [to] give the impression of nebulous objects.” That led to his cogent conclusion: that his observations of the spiral arms “speak for a large distance.” The respected Swedish astronomer soon became one of the loudest voices championing the existence of other galaxies, and Shapley began to feel sizable pressure on his beloved model of the universe under Lundmark's onslaught.
Meanwhile, Slipher, in Arizona, had dispatched a story to the New York Times revealing that he had found a new “celestial speed champion,” a faint spiral nebula that he judged had to be “enormously large” and “many millions of light years” away. And in the following year, 1922, Ernst Öpik, at the Dorpat Observatory, in Estonia, carried out an elegant calculation demonstrating how the Andromeda nebula must be some 1.5 million light-years distant. He did this by assuming that its mass and luminosity were comparable to those of the Milky Way. This “increases the probability,” reported Öpik in the Astrophysical Journal, “that [Andromeda] is a stellar universe, comparable with our Galaxy.” Thrust and parry. Thrust and parry. The duel over the island universes continued. Nothing would be settled until astronomers obtained a clear and unequivocal distance measurement to a spiral nebula—an observation so clear, so decisive, so comprehensive, that it immediately quelled all doubts.
Poor Shapley, it turns out, did put himself in jeopardy with his performance before the National Academy of Sciences gathering. Still in his thirties, Shapley was judged as too impetuous and immature to be the head of the Harvard College Observatory. Instead, his Princeton mentor, Russell, was offered the position. “Shapley couldn't swing the thing alone,” Russell confided to Hale two months after the conference. “I am convinced of this after…observing Shapley at Washington. But he would make a bully second … if he grew intellectually he would be a prodigy!”
Russell gave the Harvard directorship intense consideration, with the understanding that Shapley would be his assistant. “At this point,” continued Russell to Hale, “I would like to see your expression! I know I have my nerve with me: but,—and here I am very serious indeed,—consider what Shapley and I could do at Harvard! Between us, we cover the field of sidereal astrophysics pretty fully…and I might keep Shapley from too riotous an imagination,—in print.”
But Russell, after nerve-racking deliberation and an attractive counteroffer from Princeton, ultimately declined the job (“I would rather do astronomy,” he confided to Shapley). Harvard came back to Shapley, but not for the top position. Harvard officials brought up the title of “Chief Observer or something of the sort.” He, a bit miffed, curtly turned it down. A month later, however, Shapley reversed