The Perfect Machine (5 page)

Less than a century before, Lord Rosse in Ireland had used a huge telescope with a seventy-two-inch mirror to study and sketch spiral nebulae. The size of the telescope, and the long hours Lord Rosse put into his observations, had given credence to his claim that the spiral nebulae could be resolved into individual stars. If there were individual stars in these spirals, they might be “island universes,” separate from but perhaps equal in scale to the Milky Way. The existence of other galaxies outside the realm of our own but as large as the Milky Way, would raise havoc with Shapley’s scale for the galaxy.

In 1898 James E. Keeler had begun a survey of spiral nebulae at the Lick Observatory. Although his telescope, the Crossley reflector, had a mirror just half the diameter of the one Lord Rosse had used, the carefully figured glass mirror provided higher resolution than the speculum (polished metal) mirror in Lord Rosse’s telescope. Keeler also had the advantage of using photographic plates to record images of the spirals. A photographic emulsion can accumulate faint light over a long exposure, building up an image over a period of hours from an object that might be invisible or barely visible to the human eye. A few of the nebulae Keeler photographed, like M31 in Andromeda and M33 in Triangulum, appeared incredibly large in plates taken on the Crossley. Unless they were fundamentally different from all other observable spirals—and there was no reason to believe they were—the tiny apparent size of the thousands of other spirals observed with the reflector suggested that they must be at great distances.

Heber Curtis, who took over Keeler’s survey of the spirals, had concluded that the spiral nebulae were fundamentally different from every other form of celestial object:

Grouped about the poles of our galaxy, they appear to abhor the regions of greatest star density. They seem clearly a class apart.
Never
found in our Milky Way, there is no other class of celestial objects with their distinctive characteristics of form, distribution, and velocity in space…. The evidence at present available points strongly to the conclusion that the spirals are individual galaxies, or island universes comparable with our own galaxy in dimensions and in number of component units.

If Curtis was right—if the spirals were indeed individual galaxies, comparable in scale to our own Milky Way—then Shapley’s model,
with the globular clusters marking the edge of the Milky Way at distances on the order of one hundred thousand light-years, would have placed the spiral nebulae, as separate galaxies, at what every astronomer in 1920 would have argued were impossible distances.

In his concluding remarks Curtis relaxed his tone from the language of his formal presentation. After presenting a brief summary of the evidence on spirals, he turned to Shapley. Where, he asked, do the spirals fit in your scheme? Are they part of this enormous grand galaxy you’ve drawn in your model? Or are they, as the evidence would seem to indicate, separate “island universes,” comparable to our own galaxy, and at distances far beyond the limits of our own galaxy?

Curtis’s questions caught Shapley unprepared. Although Shapley had read the literature about spirals in the journals, he wasn’t ready for the give-and-take of a spontaneous debate on the subject. Less than a month before, he had written to his mentor, Henry Russell, that he would not say much about spirals because “I have neither time nor data nor very good argument.” In his talk he had kept to his word, never mentioning the spiral nebulae or the island universe theory. But on the floor of the symposium, before the distinguished audience, Shapley could not wave Curtis’s questions aside as irrelevant.

And, although Shapley hadn’t studied the spirals himself, a colleague of his, Adrien van Maanen, had been working on spirals at Mount Wilson since 1912. Van Maanen was charming, a bachelor, and as Shapley put it, “society.” He and Shapley had become good friends.

Van Maanen had been measuring the rotation of individual spiral nebulae by comparing photographs of the nebulae taken five years apart. He used an instrument called a stereo comparator, which compares two plates by using a movable mirror to blink rapidly from one plate to the other. If one of the thousands of images on the two plates is in a different relative position, the human eye will catch it when the mirror flips. This was the same technique Clyde Tombaugh would use at the Lowell Observatory in Arizona to search for the still-undiscovered planet beyond Neptune. Van Maanen spent so much time studying the plates of spirals on the instrument at Mount Wilson that a stern warning note was posted: DO NOT USE THIS STEREOCOMPARATOR WITHOUT CONSULTING A. VAN MAANEN.

His patience seemed to pay off. Van Maanen reported measurements of large rotations in the spiral nebulae, so large that if the spiral nebulae were at a distance great enough to be outside the Milky Way—at least a Milky Way of the dimensions Shapley proposed—the spiral nebulae would have been spinning faster than the speed of light, a proposition that anyone at the Smithsonian that night understood to be absurd, even without amplification by Professor Einstein from his seat at the head table. For Shapley, van Maanen’s evidence was persuasive. He had written to his friend, “Congratulations on the nebulous
results. Between us we have put a crimp in the island universes, it seems,—you by bringing the spirals in and I by pushing the galaxy out. We are indeed clever, we are. It is certainly nice of those nebulae to have measurable motions.”

“I don’t know what they are,” Shapley answered to Curtis’s question about the spiral nebulae, “But according to certain evidences they are not outside [our galaxy].” As proof Shapley first cited a supernova in the Andromeda Nebula, which had been discovered on a plate taken at the Lick Observatory in 1885. If the Andromeda spiral were outside the Milky Way, he argued, that single exploding star had equaled the light of millions of stars—an idea he presented as absurd. Shapley then cited van Maanen’s data in support of his own view of the size of the universe.

The respected Henry Norris Russell stood up to support Shapley’s position. But Russell’s support was too little, too late. No one else had ever produced measurements comparable to van Maanen’s. The rules of science are unforgiving: Results that cannot be reproduced are suspect.

Heber Curtis took the podium again, suddenly relaxed, ready for repartée. His question to Shapley had subtly but significantly shifted the subject of the evening. Without van Maanen’s data, Curtis pointed out, Shapley’s model of the universe collapsed on the question of the spiral nebulae. Of van Maanen’s data he said, radiating confidence and pausing for effect: “There are some observations that are not worth a damn, and others that are not worth a damn. In my opinion, two damns are no better than one damn.”

The room burst into laughter. Curtis didn’t need to say more as the guffaws of the audience erased all that had gone before. The newspaper reporters, most of whom hadn’t really done their homework or followed the details of the presentations that night, treated the laughter as a verdict. In the popular press, the great symposium on the scale of the universe, the biggest science story of the decade, was decided by a one-liner.

If the newspapers awarded Curtis a knockout, the astronomers in the audience remained divided. Some were content to ignore Shapley’s findings, either because they had been persuaded by Curtis’s arguments or because the small sample of data from a newcomer wasn’t enough to rescale the universe. Others found Shapley’s elegant method and clever use of evidence too compelling to ignore.
^*
Predictably, the participants split their decision. Curtis thought that his approach had
probably been too technical for the audience, but that overall, “the debate went off fine in Washington, and I have been assured that I came out considerably in front.” Shapley was more circumspect in his claims: “I think I won the debate from the standpoint of the assigned subject matter.”

Some were disappointed that the “scientific debate of the century,” instead of revealing definitive new truths about the universe, had turned out a draw. But for one man at the Smithsonian that evening, that very inconclusiveness was the symposium’s most important outcome. George Hale—director of the Mount Wilson Observatory, an officer of the National Academy of Sciences, a distinguished solar astronomer, and the promoter of the original topic for the symposium—diplomatically refused to take a public position on the big questions of the evening. When pressed, Hale answered in statesmanlike fashion that the evidence was intriguing but not yet persuasive.

The important word for George Hale was
evidence
. As an experienced astronomer and the director of a major research facility, he knew that the frontiers of science would always have vague borders. The issues at the symposium had been argued among astronomers for as long as men had gazed at the sky. What made it different now was that Harlow Shapley and Heber Curtis were tantalizingly close to being able to
answer
those questions. Astronomy was at the dawn of one of those breathtakingly exciting moments in the history of a science when scientists were ready to explore a whole new level of inquiry.

As the two men presented data from the most powerful telescopes in the world, George Hale thought about astronomers extending their observations and their cosmologies even further, to the very edge of the universe, to the beginning of time.

Hale was no novice with telescopes. He had already shepherded through construction three great telescopes, each larger than any before it. The next step, in his mind, was not just an increment over those machines, but a leap in technology and design, an instrument orders of magnitude larger and finer than any that had ever been built. He had enough experience with telescopes to know that to design and
build a machine on that scale and to those specifications would require an unprecedented national engineering and scientific effort: the coordination of the talents and efforts of hundreds of scientists, engineers, designers, artists, and craftsmen all over the country; the cooperation of the largest corporations, universities, and research institutions in the land; an appropriation of funds larger than any that had ever been made in support of a single scientific instrument; the extension of optics, metallurgy, control systems, and large-machine-construction technology to limits few had ever imagined possible; and a coordination of facilities and individuals that had never been attempted.

Anyplace but the America of the 1920s, it would have been an inconceivable project. The war that had humbled and exhausted Europe had been one more challenge for the United States—a challenge, like the Panama Canal or the Brooklyn Bridge, that could be solved with American resources, might, and spirit. While Europe licked its wounds, exhausted, enveloped in still-unsolved questions of diplomacy and hegemony, Americans talked of damming the great rivers of the West, bridging the Golden Gate at the entrance to San Francisco Harbor, building skyscrapers and super liners that would dwarf the achievements of an earlier era.

Even in that optimistic America of the 1920s, the machine Hale had in mind would press the limits of technology, stretching the confidence of a cocky nation perilously close to hubris. But science is compelling, the promise of timeless answers irresistible. And George Hale, as the secretary of the National Academy of Sciences had learned, was not a man to take no for an answer.

3
The Worrier

Even as a boy, growing up in Chicago, George Hale worried too much. The family firm, Hale Elevators, had profited handsomely from the construction boom after the Great Chicago Fire, and the Hale’s lived well. A few split branches in the family tree, including the divorce of George’s maternal grandparents, caused a stir in their time, but quiet money, a reputation for generosity, and a splendid town house gave William Hale and his family a secure position in Chicago society.

George was a sickly child. The doctors could find no explanation for his chronic stomach trouble, backaches, and fainting spells, so George’s mother, a semi-invalid who confined herself to dark rooms because of paralyzing headaches, prescribed her own medicine, a regimen of reading—Homer,
Robinson Crusoe, Don Quixote,
and Grimms’
Fairy Tales.
George acquired, or inherited, both her love of literature and her unpredictable, terrifying headaches.

When his mother retired to her dark room, George liked to experiment with tools and instruments. His brother and sister would discover him lost in a world of his own. When they spoke, he didn’t answer. If they made a loud noise, he seemed not to hear it. To those who had never seen the concentration of a scientist absorbed in his work, George’s behavior was mystifying. He didn’t seem an ordinary boy. On a trip to London, George’s friend bought magic tricks; George spent his allowance on an expensive spectroscope.

Each new passion became an obsession: When he became interested in microscopy, his father bought him a fine Beck binocular microscope. For months microscopy excluded all other interests, until it was replaced by the next passion. George’s father worried about his son. What would become of a boy with no focus, no plans or ambition, who preferred puttering alone to sports and friends, whose dabbling in one science after another seemed to lead nowhere?

Then George discovered astronomy. As far as anyone in the family could remember, it started when he read Jules Verne’s
From the Earth
to the Moon.
Soon nothing else mattered. He devoured books and articles about astronomy, visited observatories, interviewed astronomers and telescope makers, planned his own astronomy journal, and fired off a flurry of letters to general interest magazines, offering to write articles. He was thirteen years old.

Before his fourteenth birthday the enthusiastic young astronomer got up the nerve to call on Sherburne Wesley Burnham, a quiet Chicago court reporter by day and obsessed amateur astronomer by night. Burnham let young Hale assist him in his painstaking observations of double stars. One evening he told Hale about a secondhand four-inch telescope, built by the well-known optician Alvan Clark, that was available at the right price. It was the first of many telescopes that George decided he must have.