The Perfect Machine (3 page)

Heber Curtis, an amateur classicist as well as an astronomer, had brought Latin and Greek texts with him. Reading the classics was a gentleman’s avocation. Hour after hour he would sit with a familiar, leather-bound volume open on his lap, as if he were in a club chair in the Atheneum. Harlow Shapley was fascinated by Curtis’s choice of reading material. He had been educated a generation later, when the classics had already faded in high school and college curricula.

There was no room for extraneous reading in Shapley’s life. He thought of himself as a modern man, with a modern education. His avocation when he couldn’t work on astronomy was nature studies. He was an amateur naturalist, but he approached nature as he approached astronomy problems, carrying a notebook with him wherever he went. If he couldn’t be near the observatory and its instruments, he cataloged the species of insects or plants he found, writing notes as methodically as his logbook of observation runs on the sixty-inch telescope at Mount Wilson.

On one nature walk in California he had stumbled on a colony of ants, scurrying to and from their nest. Shapley timed how fast they were moving. What factors determined the speed of their travel? he asked in his omnipresent notebook. He gathered enough data to hypothesize that the ants’ speed of travel was determined solely by the ambient temperature. Armed with a theory, Shapley needed data. Wherever he went he would search out an ant colony and accumulate more measurements to bolster his theory.

Less than a day from Washington, on the east side of Birmingham, Alabama, the train broke down, close enough to the city that the passengers could still see the smoke-darkened skies from the steel mills. The conductors made the rounds of the cars, reassuring the passengers, but as the day went on and the train stood still under the broiling sun, the passengers grew restless and hot inside the cars. Curtis took one of his classical texts and lay down in the shade to read. As he read he could see Harlow Shapley—notebook, stopwatch, and thermometer in hand—chasing through the jasmine and the new kudzu vines that had been planted to control erosion, in pursuit of a colony of ants.

For a while, the Scale of the Universe seemed far away.

2
Washington

Washington was a sleepy town in 1920, more like the capital of a small state today than the full-time capital of a great nation. Congressmen and senators spent most of the year in their home districts, commuting to congressional sessions of limited duration. The staffs of Congress and the president each numbered a few people. It would take a dozen years before there would be a telephone on the desk in the Oval Office. The British Foreign Office classified the city as a semitropical hardship location. Even the press wasn’t there in droves yet: Washington politics weren’t considered important enough to attract permanent press bureaus or hordes of lobbyists.

April was one of the better months, before the oppressive heat and humidity of summer. The hundreds of cherry trees around the Tidal Basin, a gift only eight years before from the mayor of Tokyo, were in bloom, a welcome relief from the dank mosquito infestations that had once marked the area. Relations with the Japanese weren’t as friendly as they had been in 1912, but most Americans, after the experience of the war to end all wars, weren’t interested in other countries.

The headlines on the newspapers at Union Station were depressing. Warren Harding had replaced the ailing Woodrow Wilson, who had spent the last years of his presidency sequestered in the White House. Wags who had speculated whether Mrs. Wilson or Colonel House was running the Wilson White House now wondered whether
anyone
was running the government. The “Red scare” was in full swing. In the pages of the
Dearborn Independent
Henry Ford attacked what he called the “International Jews”; the revived Ku Klux Klan blamed the woes of the nation on the triad of Jews, Roman Catholics, and blacks; police chiefs like William Francis Hynes in Los Angeles sent squads of officers to break up union and leftist meetings; and almost everyone seemed willing to take a swipe at the Industrial Workers of the World, the Wobblies.

Fortunately there were diversions from the pall of politics. Babe
Ruth, who had pitched and played occasional outfield for the Boston Red Sox, was in his first season with the New York Yankees and proving he was worth the astonishing $125,000 they had paid to get him. Man o’ War was the Babe Ruth of the racetrack, and handsome, charming Jack Dempsey seemed equally unbeatable in the boxing ring.

In the bookstores the talk was of F. Scott Fitzgerald’s daring
This Side of Paradise.
Readers turned down the corners of the pages on which one of Fitzgerald’s heroines confessed: “I’ve kissed dozens of men. I suppose I’ll kiss dozens more,” or, “Oh, just one person in fifty has any glimmer of what sex is. I’m hipped on Freud and all that, but it’s rotten that every bit of real love in the world is ninety-nine percent passion and one little
soupçon
of jealousy.”

A few adventurous women had started wearing short-sleeved or sleeveless dresses in the evening, sometimes showing their knees and stockings rolled below the knee. A risqué few even smoked in public and went out in the evenings without corsets because, as the whispered saying had it, “Men won’t dance with you if you wear one.” They were the fringe exception, the radicals who attracted sensational press and wagging fingers from the guardians of morality. Still, it wasn’t hard to imagine that before long there would be bathing-beauty contestants in skin-tight suits with naked legs, cheek-to-cheek dancing, people getting “blotto,” and necking and petting in parked cars—exactly the stuff the moralists most feared.

The National Academy of Sciences didn’t even have a building of its own in 1920, which was why its annual meeting that year was scheduled to be held in the strange, turreted, brick castle of the Smithsonian Institution in the middle of the empty mall that ran from the Capitol to the Potomac. On the evening of April 26 a steady stream of motorcars drove up to the sheltered portico of the castle. The founders had modeled the institution after the long-established academies of Europe. They wisely stopped short of the formal dress that might have evoked protests of outrage from those who would be sure to insist on American plains pun. In France or England plumes and sashes were de rigueur. The men who came to the annual meeting of the American academy—science was not yet a proper pursuit for a woman—dressed in dark wool suits for the occasion. Even science was supposed to be democratic in America.

The ticket George Hale had gotten for Shapley entitled him to a seat at the head table, among the notables. He sat next to W. J. V. Osterhout of the Botany Department at Harvard, but the banquet had been served before Shapley had a chance to talk about his nature studies. They were still eating when the speeches began.

Stylized elocution was fashionable in 1920. A parade of long-winded speakers followed one another to the podium, first to honor the Prince of Monaco for his support of oceanographic studies, then to
praise the achievements of a bureaucrat named Johnson, who had devoted his life to hookworm control. To keep his own nervousness in check, Shapley silently cataloged the speeches: “Johnson the Scientist,” “Johnson the Operator,” “Johnson the Man.” Out in the audience he could see heads nodding off.

Einstein was at one end of the head table, next to the secretary of the Netherlands Embassy, there to accept a prize on behalf of the Dutch scientist Pieter Zeeman. During one of the speeches Einstein leaned over to whisper something to the Dutchman. Reporters later rushed to ask what Einstein had said. He said, the Dutchman reported with a grin, “I have just got a new Theory of Eternity.”

Finally it was time for the much-publicized symposium. Shapley came to the podium first. He had never before addressed a large audience of non specialists.

As Shapley looked around the room, one of the few faces he could recognize was that of his mentor at Princeton, the legendary Henry Norris Russell, the dean of American astronomy. Russell was a shy and formal professor, given to strolling the Princeton campus with his cane in hand, brushing aside students in his way and addressing even his best graduate students as if they were servants. For all his formality, Russell was an inspiring teacher, and he had been profoundly appreciative of the superb graduate student who had come his way. As Russell put it years later: “I had this struggle with darkening at the limb of an eclipsing binary. All these observations had to be worked over; it looked hopeless, and then the good Lord sent me Harlow Shapley.”

Shapley’s diligence and success studying eclipsing binary stars at Princeton earned him the prized postdoctoral appointment at the Mount Wilson Observatory, in the hills above Pasadena, California—then the home of the world’s largest telescope. Shapley, brashly self-confident, was sure “that I could do something significant at Mount Wilson if the people there gave me a chance…. My desire, almost from the first, was to get distances.”

Distances
—how far away the various objects in the heavens were from our vantage point on the earth—seem an obvious question for the astronomer. In 1914, when Shapley came to Mount Wilson, there were few convincing answers. From our perspective, in an era of powerful telescopes on earth and in space, and after a remarkable revolution in the sciences of astronomy and astrophysics, it is astonishing to realize how limited man’s understanding of cosmology was earlier in our own century. When Shapley arrived at Mount Wilson astronomers could pinpoint the location of objects within a few arc seconds,
^*
but
they had few tools or techniques to determine the distance to the objects they saw in the night sky. Kepler and Newton had provided the mathematics to calculate the orbits of planets, and refined observations made it possible to calculate the distance to the planets with remarkable precision. But even the most sophisticated observatory equipment presented objects beyond our solar system to the astronomer as they appeared to the casual observer: like pinpoints of light on the inside of a great black sphere overhead—as if they were all at the same infinite distance away. Without a method of determining distances, the myriad objects the astronomer could see or photograph in his or her telescope were effectively a two-dimensional frieze.

The methods we use to measure distance on earth are useless for astronomical distances. We obviously can’t use a tape measure or yardstick. We can’t scale the size of a familiar object the way a hiker estimates the distance across a valley by comparing the apparent size of known objects like a fellow hiker, because stars appear as pinpoints of light in even the most powerful telescopes. Triangulation—calculating distance to a remote object by measuring angles to the object from two widely separated points—is an inviting technique, but in 1914 no equipment on earth had the resolution to measure the parallax of a star from two points on earth. Even the longest baseline available to an earth-born observer—the span of the earth’s orbit around the sun—is tiny compared to the distance of the closest stars. Measurements taken six months apart show a parallax shift of the star against the background of other stars only for the closest stars.

Many astronomers reluctantly accepted the limitations of the available technology. The energy of astronomers went into the laborious and unrewarding task of cataloging data: measuring positions, spectra, and apparent brightness of stars. Columns of numbers accumulated at observatories; generations of women scribes tested their vision on the tables of copperplate numbers. The data would all,
someday,
be invaluable, the secrets to understanding the most basic questions of cosmology—as soon as someone figured out how to use it.

Shapley chose the problem of distances precisely because it was a bold enough problem to make a mark in the world of astronomy. To his good fortune, just about the time he came to Mount Wilson, there was an unexpected breakthrough in the techniques of astronomy from what many in the world of early-twentieth-century science would have thought the least likely source—a woman.

At Harvard the “computers” who worked long days and nights calculating and tabulating observational data, were women, hired by Edward Pickering, the longtime director of the Harvard College Observatory, for twenty-five to thirty-five cents per hour. They worked with quill pens and black ink, writing long lists of figures in neat script, without corrections. Pickering had turned to women out of exasperation
with a male assistant. Declaring that even his maid could do a better job, he hired Williammina P. Flemming, a twenty-four-year-old Scottish immigrant, to assist him. She stayed for a total of thirty years and before long was in charge of an entire staff of women assistants. Flemming, a divorced mother, supported herself on the meager wages Pickering paid. Other computers were college graduates interested in science. The prevailing social notion of “separate spheres” for men and women left them no room in the observatories and laboratories.

Henrietta Swan Leavitt came to the Harvard College Observatory from the Society for the Intercollegiate Instruction of Women, the forerunner of Radcliffe College, in 1895. Pickering stacked glass photographic plates from Harvard’s Southern Station observatory in Peru in front of her and told her to look for variable stars, stars that cycled in brightness.

It was tedious work. Star by star Leavitt compared glass photographic plates of the same area of sky until she found a speck that was darker or fainter than it had been on a plate taken earlier or later. With enough plates of the same area of sky, and records of when the plates were exposed, she could measure the period of the variable stars—how long it took to cycle from maximum to minimum brightness. After years of laborious measurements Leavitt had cataloged more than 2,400 Cepheid variable stars, named after the constellation Cepheus, where they were first discovered.

Not content just to catalog the data, Leavitt searched for a correlation between the intrinsic brightness of the Cepheid variables and the period of their cycle. In 1908 she tried plotting the logarithm of the period of variable stars in the Small Magellanic Cloud, and hence at the same distance, against their apparent brightness. The data on her graph fell on a straight line: Cepheids a thousand times as luminous as our sun completed their bright-dim-bright cycle in three days; Cepheids ten thousand times as luminous as our sun took thirty days to complete their cycle. By 1912 she had graphed enough data to publish an article, “Periods of Twenty-five Variable Stars in the Small Magellanic Cloud,” in the Harvard College Observatory
Circular.
After the article appeared Pickering ordered her not to pursue the subject further. His attitude mirrored what was then a widespread viewpoint: A lady of science’s place was in the back room, writing columns of numbers, not in the observatory or the scientific journals.