The Day We Found the Universe - Marcia Bartusiak [96]
Occasionally visitors were invited to look through the telescope. A favorite target was a dazzling cluster of stars in the constellation Hercules. One man, upon viewing the great cluster, remarked to Frost right before the 1908 presidential election, “So you say that each of those points of light is a sun and each one is larger than ours. And you allege that this cluster is so far away that the light requires thirty thousand to forty thousand years to reach us? Well”—with a sigh—“if this is so, I guess that it doesn't really matter whether Bryan or Taft is elected.”
Graduate work in astronomy at the University of Chicago was primarily carried out right on the premises, at the observatory itself. When Yerkes first opened, it was one of the foremost observatories of its time. But when Hale, its founder, moved to California to build his even greater astronomical establishment atop Mount Wilson, taking with him the cream of Yerkes' observers, only the older astronomers whose creative years were long over or the second tier stayed behind. Frost himself was slowly losing his eyesight due to cataracts and could no longer observe, the ultimate tragedy for an astronomer. With a few exceptions, most students who completed their PhD at Yerkes around this time made no major contributions to astronomy. Hubble, though, did not let Yerkes' declining fortunes deter him.
Right before starting at Yerkes in the fall of 1914, Hubble attended a meeting of the American Astronomical Society held on the campus of Northwestern University in Evanston, Illinois. It was the eventful meeting when Vesto Slipher presented his awe-inspiring results on the speedy velocities of the spiral nebulae, which created such a commotion. Mingling with the great astronomers of the day, Hubble must surely have sensed the importance of Slipher's announcement. Hubble was after astronomical fame (though just inducted into the AAS, he managed to get in the front row for the meeting's group photo) and here was a compelling mystery garnering everyone's attention. It could be that his decision to focus on the nebulae was made that very week, as he joined in the ovation, standing up with the audience, clapping his hands in honor of Slipher's achievement.
As a graduate student, the lowest rung in the observatory hierarchy, Hubble didn't have regular access to Yerkes' grand 40-inch telescope. But, driven and self-reliant, he took advantage of the equipment that was available to him and took over the observatory's 24-inch reflector, then standing idle, a curious situation since it was the same two-footer that George Ritchey had built years earlier to compete with Lick's productive Crossley reflector. Hubble attached a camera to the telescope and proceeded to take pictures of various nebulae. Soon these images became the topic of his doctoral thesis, “Photographic Investigations of Faint Nebulae.” His first discovery was finding that certain faint nebulae could change. He compared his photographic plate of a nebula called NGC 2261, a comet-shaped cloud of gas, with ones taken earlier at other observatories. His latest photo displayed distinct differences, indicating that the nebula had to be relatively small and close by. (This object, located within the Milky Way, is now known as Hubble's variable nebula.)
In many ways, this endeavor became a trial run for his later work on galaxies. Although Hubble's telescope was small by modern standards, he was able to discern that the faint white nebulae were not all spiral disks (as many then believed); some were also bulbous, what later came to be known as elliptical galaxies. He could also see that many of these nebulae crowded together on the sky. Much as astronomers did in earlier centuries with stars, Hubble was hoping to learn something about nebulae from their distribution over the sky. “Suppose them to be extra-sidereal [outside the Milky Way] and perhaps we see clusters of galaxies,” wrote Hubble about his findings. “Suppose them within our system, their nature becomes a mystery.” He even estimated that if they were separate