Months of polishing the surface stretched into years. The continued crises over the new telescope brought an end to the temporary remission of Hale’s dreaded symptoms. The familiar pattern returned: first a ringing in his ears and an agonizing headache, then physical exhaustion, a tingling in his feet, frantic excitement, insomnia, indigestion, spastic colitis, and the sensation that his mind was whirling out of control. The little man who had tormented him in Egypt came back, a dreaded, unwelcome companion offering unsolicited advice. There seemed to be no escape.
The early twentieth century was not an age of medical candor. Hale told no one outside a few close confidants the extent of his torments. When he did confide in a friend, like Harold Babcock, he called the collection of symptoms “Americanitis,” his term for the madness and impatience that Charlie Chaplin later portrayed in Modern Times. Other times Hale called the symptoms, onomatopoeically, the “whirligus.” Whatever he called it, Hale was powerless in the face of its tortures. He tried everything, even thanking the elf and promising to follow its advice. The whirligus would always come back.
The relapse in 1913 sent Hale back to Dr. Gehring’s sanatorium in Maine. Gehring’s diagnosis was that prolonged use of one part of Hale’s brain had allowed poisons generated in a displaced large intestine to accumulate. He labeled the condition ptsosis, and prescribed sawing wood, subconscious exercises, and light massage of the intestinal area. The treatment helped, temporarily relieving the driving headaches and sending away the whirligus. But by summer Hale needed yet another trip abroad to get away from the pressures of the observatory and the unfinished telescope. Hale’s life had become a seesaw, brief moments of relative peace alternating with the tormenting headaches and uncontrollable visions.
During one of the clear moments, in 1914, Hale interviewed an energetic young astronomer in New York. The astronomer came to the meeting primed to discuss the latest astronomical research, especially the variable stars on which he had done considerable work of his own. To his surprise Hale asked him about music, opera, drama—anything but astronomy. George Hale knew that a candidate who came with formidable recommendations from Henry Norris Russell would be a capable observer and astronomer; what he needed to ascertain was whether the man was the right sort of fellow, whether he could function well in the atmosphere of close collegiality that Mount Wilson required. The young astronomer was Harlow Shapley, who would soon be using the sixty-inch telescope for his research on globular clusters.
Through sheer force of will, Hale fought back the horrible symptoms often enough to carry on, recruiting a steady stream of first-rate astronomers for the observatory and dealing with the institutional and administrative problems of a major research institution. When the components of the huge new telescope proved too heavy to go up the mountain on mules, special trucks were bought for the treks up the mountain. The daily trips of the one-and three-ton trucks tore up the road and required regular labor teams to keep the crude path passable. Crisis after crisis came up, and with World War I beginning to draw on American resources, Hale could not turn down the invitation of the National Academy of Sciences that he assist in the organization of a National Research Council, which took over many of the laboratories and facilities at Mount Wilson for war-related research.
George Ritchey, though relieved as optician in charge of the grinding of the mirrors and other optics for the one-hundred-inch telescope, remained at the observatory, and other astronomers still chafed at his sanctimonious and sometimes sadistic attitude. His perfectionism was more than mildly annoying, not only in the time he would spend on the big telescopes, taking one perfect exposure (and, as often as not, forgetting to note the parameters that would make the plate useful for scientific purposes), but in his procrastination of any writing, so that collaborations involving him fell impossibly behind schedule. One night he helped a visiting French astronomer, Henri Chrétien, use the sixty-inch telescope for the first time. Ritchey loaded the telescope’s plate holder and Chrétien spent several hours guiding the telescope, perched precariously at the eyepiece, in freezing temperatures, pushing buttons on a paddle to hold a star image steady in the crosshairs. When the exposure was done, Chrétien knew he had done a good job and was eager to develop this, his first plate on the famed telescope. Then Ritchey told him that it was a blank, that he had not been willing to risk a good photographic plate on a novice.*
Other astronomers, especially Walter Adams, who served as acting director of the observatory during Hale’s absences, were outraged by Ritchey’s sadistic and authoritarian manner. By the middle of the war, Ritchey, who was in charge of war production at the optical shop, began signing his correspondence “Commanding Officer, Mount Wilson Observatory.”
He rarely passed up an opportunity to give the staff of the optical laboratory or visitors to the observatory his views on the one-hundred-inch-telescope project. He had spent long enough with the disk, he said, to know that it changed shape with even slight changes in position, and that the layers of air bubbles from the three separate pours had fatally weakened the glass. Ritchey’s success in figuring the mirror for the sixty-inch telescope weighted his predictions. Doubts about the new telescope were widespread.
5
First Light
Their hundred inch reflector, the clear pool,
The polished flawless pool that it must be
To hold the perfect image of a star.
And, even now, some secret flaw—none knew
Until tomorrow’s test—might waste it all.
Where was the gambler that would stake so much,—
Time, patience, treasure, on a single throw?
The cost of it,—they’d not find that again,
Either in gold or life-stuff! All their youth
Was fuel to the flame of this one work.
One in a lifetime to the man of science,
Despite what fools believe his ice-cooled blood,
There comes this drama.
If he fails, he fails
Utterly.
—ALFRED NOYES, WATCHERS OF THE NIGHT
It was 1917 before the telescope was ready for first light.
The weather was clear and cool when the group left Pasadena for the drive up to Mount Wilson, the kind of November evening in Southern California that condenses enough moisture to require windshield wipers on a clear evening. Pasadena is a flat city, with streets laid out in a rectangular grid. Were it not for the palm trees that line the main streets, the stucco exterior walls, and red tile roofs, it could pass for a midwestern city.
The mountains arise abruptly at the northern edge of the city. As the party drove up the rugged nine-mile path from the base of Mount Wilson, through patches of scrub oak, sagebrush, and black-cone fir, layers of fog closed in, first scattered, and then so dense that driving was difficult. Only at the summit, at 5,700 feet, did they break through the fog that obscured the light of the sprawling Los Angeles basin below.
The city’s pain was the astronomers’ gain: The frequent fogs below the summit, and the inversion layer that trapped pollutants in the Los Angeles Basin, were a blessing on Mount Wilson. The fog scattered and occluded the light of the city below, and the inversion stabilized the atmosphere. From the peak the sky overhead was filled with stars, pinpoints in a celestial dome of black velvet. The stillness of the atmosphere left the star images stable, without the twinkle that inspires poets and frustrates astronomers. Mount Wilson has among the best seeing of any observatory site in the world.
That cold November night in 1917, twenty men walked across the narrow wooden drawbridge to the one-hundred-inch telescope. The dome was immense, dwarfing the dome of the sixty-inch telescope in the distance. A table had been set up so each of them could sign the logbook that W. P. Hoge, night assistant on the sixty-inch telescope, used to record the evening’s events.
The great telescope loomed above them, a seventy-five-foot-high erector set of riveted black steel girders and huge brass gears. An astronomical tel
escope is an impossible combination of the scale of a battleship and the precision of a microscope. The heart of the telescope was a fraction of an ounce of silver, the coating of the great mirror that had been polished to as perfect an optical shape as the opticians could achieve. Everything else—the whole huge structure of girders, gears, bearings, and drive mechanisms—was there to cradle and aim that ounce of silver.
The mounting had been fabricated by the Fore River Shipbuilding Company in Quincy, Massachusetts—a division of Bethlehem Steel more accustomed to building naval gun turrets than precision optical devices. Sections of the telescope tube were so large they had to be shipped around Cape Horn to Los Angeles Harbor. Assembled, the instrument weighed one hundred tons. The clock mechanism alone required a ton of bronze castings, one and a half tons of iron castings, a two-ton driving weight, a seventeen-foot driving wheel, and a maze of hand-machined gears, each wider than a man’s reach. Altogether the telescope, dome, and shutters needed thirty electric motors to move them.
The great one-hundred-inch-diameter mirror was mounted at the bottom of an open tube of riveted steel, eleven feet in diameter and more than forty feet long. The tube pivoted at its center in a heavy steel yoke; motors turning hand-machined gears rotated the tube on the pivots to direct the telescope to objects higher or lower in declination. The steel yoke was suspended at each end on huge floats in mercury bearings and precisely aligned with the axis of the earth, so that as the telescope turned synchronously with rotation of the earth, the heavens would seem to stand still. The massive yoke was designed by Francis Pease, an astronomer at the observatory, in the so-called English style, with the north end closed. The price of the great rigidity was that the telescope could not be lowered enough to be aimed at objects around the north celestial pole. This telescope would never see Polaris.
The auxiliary mirrors, eyepieces, spectroscopes, and other instruments that would record the light of faint objects were mounted at the opposite end of the tube from the mirror, all in precise alignment with the primary mirror. A deviation of a fraction of a millimeter in the alignment would degrade the image. The tiniest wobble in the mounting would make the image too unsteady for photography or spectroscopy. Astronomical telescopes are unforgiving instruments.
The twenty men on the mountaintop that night included astronomers, machinists, electricians, and carpenters. Hale had also invited the poet Alfred Noyes, in the hope that he might capture and record the majesty of the occasion of first light. Hale deliberately did not invite the press. Hale had a scientist’s skepticism of journalistic oversimplification and sensationalism. Noyes captured Hale’s fears of the press:
As for the stars, if seeing them were all,
Three thousand million new-found points of light
Is our rough guess. But never speak of this.
You know our press. They’d miss the one result
To flash “three thousand millions” round the world.
Once the sun dropped below the horizon, the only illumination inside the dome was dim red night-lights. They too would be turned off when the actual observations began. Through the open shutters of the huge dome, the visitors could see the sky, punctuated with uncounted pinpoints of light. Even for the experienced astronomers, who had spent hundreds of nights on mountaintops with the big telescopes, it was an inspiring sight. Mountaintop observatories create the feel of a cathedral, with the heavens as their ceiling.
If it worked, the new telescope would almost triple the light-gathering ability of the sixty-inch telescope Shapley had used for much of his work. But in 1917 no one could say for sure whether a telescope as large as the new one-hundred-inch reflector would ever achieve its theoretical resolution of faint and distant objects. The effective resolution of a large telescope is limited by the turbulence of the earth’s atmosphere. Mixed air of varying density, which produces the twinkling of stars, leads to irregular refraction under magnification: Stars appear as blurred images instead of pinpoints of light. The larger the lens or mirror of a telescope, the more light rays from widely separated paths are united in a single image, and the more sensitive the instrument becomes to the tremors of the atmosphere. Even at a site like Mount Wilson, with its superb seeing, there were many who thought that the sixty-inch telescope was already pressing against the limits.
Although the new telescope was intended for use almost exclusively for photographic and spectrographic work, an eyepiece was mounted that evening so they could visually test its resolution and light-gathering ability. When the sky was dark enough, Walter Adams pressed buttons on the control panel to swing the great telescope around toward Jupiter. The others gathered around the base of the telescope as Hale was given the privilege of the first look through the eyepiece. He climbed the ladder to the eyepiece, high above the concrete floor, stared for a moment, then came down the ladder without saying a word.
Adams, an astronomer and experienced optician, went next. He couldn’t believe what he saw through the eyepiece. Instead of a single image of Jupiter, there were six or seven overlapping images in the eyepiece. “It appeared,” Adams later wrote, “as if the surface of the mirror had been distorted into a number of facets, each of which was contributing its own image.” If that was the best the telescope could do, it was worthless for astronomical work.
Hale and Adams looked at each other, wondering if the predictions of doom for the big telescope had come true. Had telescope building reached its limit? Had they labored for most of a decade—raising the funds and painstakingly building the giant machine—for nought?
Then someone recalled that the workmen on the mountain had left the dome open during the day. Maybe the sun shining on the mirror during the day had heated it enough to distort the images. The astronomers waited around. Every fifteen minutes one of them climbed the ladder to check the eyepiece, until someone suggested that a watched pot doesn’t boil.
Adams and Hale walked glumly from the new dome down to the Monastery, the multiple images of Jupiter fresh in their minds, Ritchey’s predictions of failure hung in the air like a curse. Already astronomy in the United States had divided into two camps: While the California astronomers worked on building bigger and better instruments, astronomers at some of the eastern universities, with limited access to good viewing sites, argued that astronomy didn’t need bigger or fancier instruments. What was needed, they said, was more and deeper analysis of the data that was already available, accumulated in thousands of painstakingly compiled ledgers at the observatories. Ritchey’s assessment of the new mirror added fuel to the fires. Outside the Mount Wilson offices and optical laboratories, there was no shortage of doubters, who had joined Ritchey in predicting failure for the machine.
Hale and Adams agreed to meet at the telescope at three in the morning for another look.
In his room at the Monastery, Hale didn’t even undress. He couldn’t sleep and couldn’t concentrate on the mystery he had brought with him. He knew the new telescope wasn’t without problems. Some were the results of deliberate compromises. Francis Pease’s design for the mounting provided great rigidity, and the mercury flotation systems on the pedestal bearings provided smooth motions, but the support beam at the end of the closed cradle made it impossible to lower the telescope to point at the celestial pole. To insulate the telescope from changes in the air temperature outside, the dome had been fabricated of a double thickness of thin sheet steel, with an insulating air space between. Still, it didn’t take extensive calculations to determine that the immense plate-glass mirror would be slow to adjust to changes in the ambient temperature.
At two-thirty in the morning, earlier than they had planned to meet, Hale walked back to the dome. Walter Adams showed up too, confessing that he also couldn’t sleep. By then Jupiter was out of reach in the West. They chose a bright star for their second test. The night assistant didn’t identify the star in the logbook.* After the earlier observations of Jupiter, they probably assumed that the logbook would be short-lived.
Again they slewed the telescope around, and again Hale climbed the ladder to take the first look through the eyepiece. This time he came away from the eyepiece with a broad smile on his face. For the first time in years, his impish eyes sparkled. “With his first glimpse,” Adams remembered, “Hale’s depression vanished.” Adams took a look for himself. The image of the star stood out in the eyepiece as a single, sharp point of light, dazzling in its brilliance. Within hours everyone on the mountain had come over to take a look through the eyepiece.
Spirits were high, but even with the most spectacular images anyone had ever seen in a telescope eyepiece, the results of the evening had been a mixed success. The long, cool hours of the night had been enough to let the mirror resume its normal figure, but further tests confirmed that it took twenty-four hours to cool the mirror of the telescope ten degrees Celsius. During the cooling period the telescope was useless for accurate observations, which meant that sudden changes in the weather on the mountain would severely limit its use. The addition of a cold-water pipe system behind the disk, an effort to maintain the temperature of the mirror, didn’t really help because the night temperatures on Mount Wilson were unpredictable. The only way the telescope could be used without the disasters of that first night was to keep the dome tightly closed all day, with the mirror housed in a cork-lined insulating chamber. And even when a complex routine was established to limit the thermal instability of the mirror, it became clear during the later testing that the definition of the telescope fell off in certain inclinations. The one-hundred-inch was a temperamental machine.
Yet for all its teething problems, the telescope put to rest the doubts that had raged about whether the atmosphere, even at a site like Mount Wilson, was steady enough to permit a large telescope to reach its limits of resolution. Within months observers were using the telescope to reach out to distant objects too faint to resolve on the sixty-inch telescope. As bugs in the mirror supports and temperature stabilization procedures were gradually worked out, the telescope produced significant results. Exposures for images and spectrograms of distant objects that had required several nights on the sixty-inch could be completed in a single session on the one-hundred. On a good night, when the mirror settled down and behaved itself, the telescope could resolve faint objects well beyond the reach of the sixty-inch telescope. Astronomers queued up for time on the machine. The limits of the universe, the elusive edge that tantalizes astronomers, had been pushed back.
The Perfect Machine Page 8
