The Day We Found the Universe (30 page)

When writing about this point of his life, right after his return from Oxford, Hubble's early biographers uniformly noted that he soon passed the Kentucky bar examination and briefly practiced law in Louisville. That was the story that Hubble told everyone, and it became the standard line for all of his life and several decades afterward. But in truth he did neither. According to a later biographer, Gale Christianson, the closest Hubble came to a legal career was translating what may have been legal correspondence for a Louisville import company conducting business in South America. There is no evidence whatsoever that Hubble handled a professional legal case, despite what he wrote his chums back in England. Hubble was adding more mythic gloss to his résumé. All this time he was actually teaching at the high school in New Albany, Indiana, across the Ohio River from Louisville. For a year he taught physics, mathematics, and Spanish—an experience he never openly discussed later, even though his students were obviously fond of him. After Hubble coached their basketball team to an undefeated season and a third-place finish in the state tournament, they lovingly dedicated the school's 1914 yearbook to him.

High school teaching, though, hardly satisfied Hubble's steadfast hunger for a more illustrious career. He would come to see the fellow Rhodes scholars in his group become respected journalists, authors, poets, and congressmen. He yearned to match their potential in the field of science. “So I chucked the law,” Hubble later reminisced, maintaining the fiction of having had a legal career, “and went back to astronomy and the test was this—I knew it was astronomy that mattered and that I would be happy in astronomy if I turned out to be second-rate or third-rate.”

Earliest known photo of Edwin Hubble with a telescope. Taken in 1914
in New Albany, Indiana, upon his return from Oxford.
(Reproduced by
permission of the Huntington Library, San Marino, California)

With his father's daunting presence no longer an obstacle to his long-standing aspiration, Hubble contacted his favorite astronomy professor at Chicago, Forest Ray Moulton, to inquire about returning for graduate studies. Moulton wrote a glowing letter of recommendation to Edwin Frost, then director of the Yerkes Observatory. Hubble, said Moulton, was a “splendid specimen,” who showed “exceptional ability” in science. Frost promptly took him on, offering a scholarship that covered his $120 tuition and provided $30 a month for basic living expenses.

Frost, who hailed from New England, had joined the staff of Yerkes just months after it first opened in 1897, chosen by Hale to be its first professor of astrophysics. He was best known for his measurements of the radial velocities of the stars (how fast they were moving either toward or away from the Earth) and also served as managing editor of the
Astrophysical Journal
. One day he received a telegraph from a reporter with a plea: “Send us three hundred words expressing your ideas on the habitability of Mars.” A man of good humor, Frost replied, “Three hundred words unnecessary—three enough—no one knows.”

As director, Frost divided the nights at Yerkes, with astronomers working only the first or second half, so they could get some sleep. Certain hours were given over to spectroscopic work, other hours for determining the distances to the stars. In the remaining hours, the observers would carry out such tasks as photometric studies—determining the brightness of stars—or visually observing interesting objects, such as double stars.

In the winter temperatures at Yerkes could reach 15° to 20° F below zero, yet the dome couldn't be warmed as the temperature had to closely match that of the outside. Otherwise, currents of warm air rising in front of the lens would spoil the resolution of the celestial objects in the telescope's sight. “Those who have visited a large observatory on such a night,” Frost recalled, “say that they will never forget that cold eerie place, silent except for the persistent ghostly ticking of the driving clock and the wind howling around the slit in the dome. But there the astronomer sits in his Eskimo suit or fur coat and cap with his eye glued to the eyepiece of the telescope, watching closely to see that his star does not drift away from the crossed spider-threads which mark the center of his field while a plate is being exposed.”

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 galaxies, each the size of the Milky Way, they would have to be millions of lightyears distant to appear so small.

While seemingly prescient in his speculations, his findings at this point were not terribly revolutionary. Others, like Curtis and Slipher, had already made similar statements. Today astronomers judge Hubble's thesis as not very good technically, as it contains few references to earlier work and offers confusing theoretical ideas. “But it shows clearly the hand of a great scientist groping toward the solution of great problems,” Donald Osterbrock, Ronald Brashear, and Joel Gwinn emphasized in an evaluation of Hubble's work. “Hubble was never an outstanding technical observationalist… but he always had the drive, energy, and enough skill to use available instruments so as to get the most out of them… He recognized the right questions to ask, and he had the self-confidence to see what was on his plates, and describe it, where others who had perhaps seen it before had ignored it, or worse, tried to ignore it, because it did not fit the current pictures of the universe that they had in their minds.”

Hubble was certainly astute enough to realize that his initial research on the nebulae merely scratched the surface. In his thesis he made sure to note that his “questions await their answers for instruments more powerful than those we now possess.” He was already thinking ahead, keenly aware that another place, the Mount Wilson Observatory, in southern California, was swiftly becoming the world's premier astronomical institution, with a record-breaking 100-inch telescope under construction. In turn, Mount Wilson's director, Hale, was similarly aware of Hubble. He had been hearing reports of an exceptional young man at Yerkes who was looking into faint nebulae and, after consulting with University of Chicago professors, he offered Hubble a job, contingent on the successful completion of his doctoral degree.

“I have offered Hubbell
[sic]
a position with us at $1200. per year,” wrote Hale to Adams, his second in command. “He will talk the question over with Frost in the near future.” Frost had no problem with Hubble leaving Yerkes. In fact, the Yerkes director was probably relieved, for he didn't have the money to offer his graduating student a well-paid position, as he had hoped, and was glad to hear that Hubble had another prospect in hand, and an excellent one at that.

In the course of working toward his degree, Hubble had spent hundreds of hours at his scope, photographing a vast array of nebulae and classifying them. Yet, as published, Hubble's thesis consisted of just nine pages of text, eight pages of tables, and two photographic plates. That it turned out a bit thin was largely due to the unusual circumstances of its final preparation. Hubble had planned to finish up in June 1917, but on April 6 of that year Congress approved President Woodrow Wilson's plea for the United States to enter World War I. Within days Hubble asked Frost for a letter of recommendation to obtain a commission in the army. Upon hearing that officers' training camp was starting in mid-May, Hubble hurriedly submitted the latest draft of his thesis, which he knew was decidedly “scimpy.” On the advice of Frost, he plumped it up a bit by attaching his paper on NGC 2261, his variable nebula. Even then, Frost did not find it suitable for publication in the prestigious
Astrophysical Journal
and eventually sent it to the lesser
Publications of the Yerkes Observatory
. War fever obviously allowed Hubble's shakily composed thesis to pass without major rewrites. The young recruit handled himself superbly during his final oral examination, though, and the six-man committee awarded him his doctoral degree magna cum laude. Three days later, on May 15, he reported for duty at Fort Sheridan, a military reservation on Lake Michigan, north of Chicago.

As for his promised position at Mount Wilson, Hubble had already sent a letter to Hale a month earlier telling him of his desire to enter the reserve officers corps and asking how it would affect his job offer. Hale replied it was “natural” to apply for a commission and said he hoped “to renew as soon as you are able to accept it.” Hale even supplied one of Hubble's needed recommendations to enter officer training.

For a year, Hubble's army division stayed in the United States, largely relegated to teaching new recruits. At one point his astronomy background came in handy. His commanding officer requested that he instruct his fellow trainees how to use the stars to guide their nighttime marches. While others joined the artillery and were commissioned as lieutenants, Hubble chose the infantry, where he could enter at a higher rank, as a captain. By September he was put in charge of the 2nd Battalion, 343rd Infantry Regiment of the 86th Division at an Illinois base. “Stirring times,” Hubble wrote a friend from his new camp. “I can't picture myself missing the gathering, as it were, of the clans.”

Commended for his contributions, Hubble was promoted to major, just eight months after he joined. He finally made it to Europe in September 1918, his men reassigned to various divisions to serve as replacements. Hubble was sent to a combat training camp in France, but what exactly happened afterward is debatable (his full military record was destroyed in a fire). Hubble always claimed he saw some action in the trenches and later told his wife that he had been rendered unconscious at one point by a shell exploding nearby and awoke in a field hospital, whereupon he quickly dressed and departed. Nowhere in his discharge papers, though, is there a record of his participation in any battles, engagements, or skirmishes. Beside each listed category, only the word
none
appears. Furthermore, no “wound chevrons” were authorized for him to put on his uniform. Perhaps his exploits were never precisely documented in the fog of war or possibly Hubble was fastening more adornments to his reinvented self, tall tales that Grace proceeded to faithfully record, with unquestioning belief, in a memoir after his death. What seems most honest and unadorned is what Hubble wrote to Frost right after the war ended: “I barely got under fire.”