The Day We Found the Universe (37 page)

Edwin Hubble in his office with a picture of the Andromeda galaxy
(Hale Observatories, courtesy of AIP Emilio Segrè Visual Archives)

But Hubble didn't see any pressing need to abolish the “venerable precedent” of preserving the word
galaxy
for the Milky Way alone. The term originated from
galakt
, the Greek word for milk. As a purist, Hubble chose the Oxford English Dictionary as his final arbiter. At the time its pages said the term
galaxy
was “chiefly applied to a brilliant assemblage…of beautiful women or distinguished persons.” “The term
nebulae
offers the values of tradition; the term
galaxies
, the glamour of romance,” concluded Hubble. According to historian Robert Smith, which code word an American astronomer used quickly pinpointed whether they came from the East or West Coast. The intense Hubble-Shapley rivalry had extended into a surprising new sphere. It wasn't until Hubble's death in 1953 that the term
galaxy
became the universally accepted moniker.

Van Maanen was obviously panicky once Hubble's findings were officially out. He soon wrote Shapley asking if there was a list somewhere in the literature of every observation of a nova. “I want to compare them with the novae in spirals,” he said. “After Hubble's discovery of Cepheids I have been playing again with my motions and how I look at the measures.” He was clearly baffled. “I cannot find a flaw in [my measurements of] M33, for which I have the best material. They seem to be as consistent as possibly can be.” He understood that there were two sets of observations in circulation—his and Hubble's—that arrived at “radically different conclusions.” He planned to take more plates for a reassessment.

But Shapley by now had completely switched sides and in response at last lowered the boom on his good friend. “I am completely at a loss to know what to believe concerning those angular motions; but there seems to be no way of doubting the Cepheids, providing Hubble's period-luminosity curves are as definite as we hear they are,” he replied. When van Maanen a few years later again tried to defend his spiral work to Shapley, the Harvard Observatory director replied that he didn't “know what to think of your confounded spirals… There is little chance that we can get the universe out of this mess.” He avoided the topic with van Maanen from that point on.

Considering himself a gentleman at heart, Hubble didn't openly argue with van Maanen either, and hardly anyone else in the astronomical community appeared particularly concerned. But behind closed doors, it was another matter altogether. Personally Hubble felt that van Maanen's paradoxical findings lingered as a stubborn stain on his great accomplishment, a blemish that tarnished his otherwise sterling reputation. In her memoirs, Grace Hubble cheerily declared that the van Maanen episode hardly affected her husband at all, but she told others privately that “van Maanen's contradiction disturbed her husband so greatly from the late 1920s into the 1930s that he sometimes came home from the office and lay on his bed until his anguish abated.” Hubble had been aiming a critical eye at van Maanen's findings for quite a while and had begun preparing a series of private manuscripts, even before he announced that the Milky Way was not the only galaxy in the universe. His sole objective: to find out where van Maanen had gone wrong.

For several years, Hubble kept his doubts to himself and his covert manuscripts stashed away in his office drawer. It appeared that the Hubble–van Maanen conflict would just wither away, likely remembered, if at all, as a minor episode in the history of the island-universe debate. That would have been the case, except that van Maanen was perversely unwilling to admit defeat. He began remeasuring some of his spirals and in Mount Wilson's 1931 annual report it was announced he had found in M101 “a decided internal motion in the same direction as was found in his original measures of this nebula.” With this surprising new strike, the battle was reignited. “They asked me to give him time. Well, I gave him time, I gave him ten years,” responded Hubble to the latest assault. Now faced with van Maanen's implicit slap in the face, the former boxer put his gloves back on and rushed headlong into one of Mount Wilson's most fabled tempests. It had already been simmering in regard to telescope use. Van Maanen was sure that Hubble had been heading up a cabal to deny him a fair share of time on the 100-inch. That's when van Maanen slapped his sign on the front of the Blink, warning others not to use the machine without his permission.

The skirmish even extended into the dining room atop Mount Wilson. Seating arrangements for lunch at the Monastery followed a strict protocol: The observer scheduled to use the 100-inch telescope always sat at the head of the table, the 60-inch-telescope observer to his right, and the solar-tower observer to the left. Down the table it went in order of diminishing telescopic prominence. But one day Hubble arrived on the mountain for a run on the 60-inch and slyly switched the napkin rings, each specially marked with a staff member's name. When the dinner bell rang van Maanen, then working on the 100-inch, proceeded into the dining room and found himself placed lower down, with Hubble victoriously positioned at the table's prime spot. It was the ultimate insult one could receive on the mountain.

Drawing on his former legal training, “Hubble skillfully employed trial tactics to attain a favorable verdict from the court of science,” contends Hubble scholar Norriss Hetherington. First Hubble got his observing partner, Milton Humason, to photograph the Triangulum spiral over two nights in September 1931. He then compared this latest image with a photograph of the same galaxy taken in 1910. This was followed by new photographs of other prominent spirals long studied by van Maanen, such as the Whirlpool and Pinwheel galaxies. Hubble spent hours and hours comparing the old and new plates—picking out comparison stars, just as van Maanen did, and looking for telltale signs of rotation over the years. In the end, he concluded that “no evidence of motion” could be found. In a strategic coup de grâce, Hubble commandeered Seth Nicholson, who had assisted van Maanen in his earlier measurements, to examine the plates as well. This time Nicholson saw no changes whatsoever, at least within the range of probable error. The clever prosecutor had gotten a key witness to reverse his opinion on the courtroom stand. It appeared that van Maanen had made a personal error in regard to spiral rotation, simply finding what he expected to find.

Hubble wrote up his findings for publication, but his bosses were not pleased at all with his first draft. Breaking all the rules of dispassionate scientific discourse, Hubble's grudge with van Maanen was starkly visible upon the page. “Its language was intemperate in many places and the attitude of animosity was marked. He objected to any material change in the wording and a deadlock seemed to be indicated,” confided Mount Wilson director Walter Adams to the president of the Carnegie Institution of Washington, John Merriam. Like the preparations for a treaty between two warring nations, resolution involved delicate diplomacy, although in this case the principals involved worked at the same place. Frederick Seares, who served as the editor for papers written at Mount Wilson, did not want the battle to go public. If he solely published Hubble's criticism of van Maanen's work, it would be as if he were taking sides. A serious man known for his courtly manner, Seares wanted to maintain a certain decorum. Otherwise, morale at the observatory could plummet.

Seares decided that it would be best to prepare a joint statement, to be published under all the names of the people involved in reviewing the case—Hubble, van Maanen, Nicholson, as well as Walter Baade, a new staff member who had also assisted. All the parties agreed to this cooperative effort—except for Hubble, who opposed it violently. He declared “no compromise, no compromise” as the truce was worked on, insisting on no watering down of his views of the evidence. Hubble was sure he was right and van Maanen wrong. Adams was appalled by this response. “I do not feel that Hubble's attitude in this matter was in any way justified… This is not the first case in which Hubble has seriously injured himself in the opinion of scientific men by the intemperate and intolerant way in which he has expressed himself,” Adams reported to Merriam. Seares was so exasperated by Hubble's pigheaded attitude that he was almost ready to tell him, “Print what you like, but print it elsewhere.”

It was a moment when Hubble's discretion and judgment completely failed him. Although all the facts were assuredly in his favor, his obstinate manner in this episode deeply hurt his relations at the observatory. “The attitude of van Maanen in the matter was much superior to that of Hubble,” concluded Adams. “Hubble, who had much the better of the general weight of evidence, showed a distinctly ungenerous and almost vindictive spirit.” Hubble had become the big man in astronomy and could tolerate no lesser colleagues. He had begun to blithely ignore his duties on international committees when the chores didn't suit his schedule and was also less willing to join cooperative projects at the observatory, acting more as an individual driven by personal ambition than as a member of a larger staff. Adams lamented that he “recognized this curious ‘blind spot’ in almost every important dealing” he had with Hubble.

Hubble's increasing worldwide fame was inflating his ego, already outsized as it was. Never great pals with his astronomical colleagues, he widened the breach with his boorish behavior. He broke promises, ignored vital correspondence, took more travel than the norm (with pay), and failed to show up at meetings that he said he would attend. Adams's remarks were a reflection of the growing irritation at Mount Wilson with this loutish conduct, but it was hard to rein in the observatory's most famous staff member. Hubble was, after all, the discoverer of the modern universe. Hubble's family, too, was deeply affected by his self-centered concerns. When his mother died in 1934, Hubble did not try to return from England, where he was then traveling, once he was cabled the news. By then he hardly interacted with his family or helped them much financially. Never once did Grace meet her in-laws. “Great men have to go their own way,” his youngest sister, Betsy, said with resigned acceptance many years later. “There is bound to be some trampling. We never minded… With Edwin, it was out of sight, out of mind. When he was with you, you were the only person in the world, but if you were away, he would forget you. His head was in the stars.”

In the end, Hubble and van Maanen grudgingly arrived at a gentleman's agreement. After much discussion with Adams (and a lot of arm-twisting), Hubble at last consented to publish a brief statement on his own, which was to be accompanied by a paper by van Maanen in which he acknowledged the existence of possible errors in his research. Hubble's brief note came out in the May 1935 issue of the
Astrophysical Journal
. It was a mere four paragraphs plus a table, summarizing his measurements of M81, M51, M33, and M101. All arrived at the same conclusion: no “rotations of the order expected.” In an orchestrated move, the
Astrophysical Journal
had van Maanen's paper immediately follow. After including new plates taken with the 100-inch telescope in his reevaluation, van Maanen conceded that his measured motions were now smaller. “[My] results, together with the measures of Hubble, Baade, and Nicholson…make it desirable to view the motions with reserve,” he stated. Van Maanen promised a “most searching investigation in the future,” but as the years progressed he never followed up.

The one nagging discrepancy keeping Hubble from his full triumph—the unquestioned discovery that the spiral nebulae were truly separate galaxies—was at last resolved. In print, the two adversaries symbolically shook hands and went their separate ways. But, from that point on, whenever the two passed each other in the observatory hallways, they exchanged not a word.

Using the 100-Inch Telescope
the Way It Should Be Used

W
hile it appeared that Hubble had clinched astronomy's brass ring, solving the mystery of the spiral nebulae once and for all, a nagging problem remained: how to explain the galaxies' astounding velocities, first spotted by Vesto Slipher in the 1910s. Why were the spiraling disks speeding away from us? They “shun us like a plague,” exclaimed Eddington. It was a puzzle whose solution would prove to be even more momentous than Hubble's settling the island-universe controversy.

Hubble began to focus his full attention on the cosmic exodus in 1928. That summer the International Astronomical Union was holding its triennial general assembly in the picturesque city of Leiden, set along the Old Rhine in southern Holland. With fine weather to entice them, more than three hundred delegates attended the gathering, where they were entertained with boat excursions down the city's noted canals, gliding past scenery painted by Rembrandt three centuries earlier. It was the height of the Roaring Twenties, and Europe was overflowing with tourists. “Most of the Americans appear to be over here this summer, always on the run scooping up culture with both hands, buying walking sticks and spats, post cards,” noted Lowell astronomer Carl Lampland, who attended the meeting.