First Light: The Search for the Edge of the Universe Page 3

  A leading scientific instrument usually remains on the cutting edge of science for a few years, until a better instrument comes along, but the Hale Telescope has been breaking trail into the deep for forty years, principally because of the Palomar gadgeteers. The Hale is no longer the largest telescope on earth—Caltech recently built a larger one, called the Keck Telescope, on Mauna Kea in Hawaii, which has a mirror made of glass segments that add up to the equivalent of a four-hundred-inch telescope. The Hale Telescope is, however, world-class. It contains a suite of hypersensitive instruments, of which 4-shooter is one. These instruments, together with the size of the telescope’s mirror, make the Hale one of the best telescopes on earth. The Hale is a masterwork of Depression engineering, the Apollo project of the 1930s. Colossal, welded, gray, aloof, massive, agile, apparently indestructible, and uncompromisingly and magnificently extragalactic, the Hale Telescope stands among all telescopes as the climax of dreadnought design. There will never be another telescope like the Hale, because, in the first place, no amount of money could build the Hale Telescope today, and in the second place, the philosophy of telescope design has changed. A new generation of earth-based telescopes is being built, containing large mirrors hung in airy frames, built more like aircraft than ships. Then there is the Hubble Space Telescope, which is a canister that was tipped into orbit three hundred miles above the earth, from the cargo bay of the space shuttle Atlantis. But for the time being, the Hale is the world heavyweight champion. The Hale will likely continue to be regarded as one of the world’s great telescopes until well into the twenty-first century.

  The Hale is a versatile telescope. In addition to its two-hundred-inch primary mirror, it contains a total of eleven smaller mirrors that can be moved and angled in order to reflect and condense light into various points inside or near the telescope, where instruments can be placed. The Hale is a refinery for light. It collects a huge amount of starlight and pours it into a minuscule area. When 4-shooter is plugged into the Hale, starlight lands on the Hale’s primary mirror and bounces up to a small secondary mirror (four feet across) at the top of the telescope. The light then bounces downward into 4-shooter, sitting in the hole in the two-hundred-inch mirror. By the time the starlight enters 4-shooter, it has been narrowed down from a beam two hundred inches across into a beam fourteen inches across. The beam of starlight enters a window in 4-shooter, where it is further shrunk and bounced among mirrors. Finally it lands on four electronic chips known as CCDs. Each chip is the size of a child’s fingernail. In the end, the light that falls on the main mirror of the Hale Telescope—209 square feet of starlight in all—is distilled onto four chips having a total surface area equal to one postage stamp.

  The Hale Telescope as drawn by Russell W. Porter in 1939, before the telescope was finished. Even though he could only imagine it in its finished state, Porter captured the grandeur of the Hale. The telescope’s tube is the open structure of girders. The prime focus cage, where an astronomer can sit and stare directly into the mirror, is at the upper left of the picture, at the top of the telescope. The mirror is at the bottom of the tube, lower right. The curved horseshoe bearing is toward the upper right of the picture, profiled against the night sky, which is apparent through the open dome slit. (Photograph courtesy of Palomar/Caltech)

  4-shooter is Jim Gunn’s favorite toy. It can take four pictures of the sky simultaneously. These pictures can be joined edge to edge to make a four-paneled mosaic. 4-shooter has taken pictures of newborn stars shining through dust cocoons, and of elderly carbon stars coughing bubbles of hydrogen, and of sheets of gas blown from stars that have exploded and died. The camera has made images of dwarf galaxies, of starburst galaxies, and of elliptical galaxies studded with warty globules of stars. It has unveiled the explosive central nuclei of Seyfert galaxies and has looked into their quasarlike cores, filigreed with sable dust. It has taken snapshots of colliding galaxies flinging away threads of stars as they dance and merge with one another. 4-shooter has exposed supergiant cannibal galaxies feeding upon other galaxies for lunch. 4-shooter has imaged rich swarms of galaxies interorbiting like clouds of gnats, and it has mapped gravitational lenses, which are warps in spacetime that break the light of quasars into double, triple, and quadruple mirages from the dawn of time.

  Moving quickly around the cage, Gunn appeared to be a tiny figure fighting a tangle of wires, dwarfed by the immensity of the Hale Telescope. He could not see what he was doing, because he had inherited a set of nearsighted eyes from his father. “I can’t see up close, and I can’t see far away, either,” he would say, explaining that he owned a large collection of Woolworth spectacles of varied magnifying powers that he planted everywhere from Princeton to Caltech to Palomar Mountain in order to have a pair of glasses within reach whenever he needed them, but at the moment he had forgotten to leave a pair of glasses inside the Hale Telescope. He hit a switch.

  “Donz,” he called into an intercom. He was calling for his fellow astronomer Don Schneider.

  “Greetings,” a voice crackled.

  “I need a pair of young eyes,” Gunn said.

  A door in the wall of the dome flew open, and Don Schneider ran onto the dome floor and scrambled up the stairs into the cage. In addition to his blond hair and beard, Don had a narrow face and intense, flickering blue eyes. He pulled a wool cap down nervously over his head and said, “It’s going to be chaos tonight.” He stood well back from Gunn’s tangle of wires.

  “Take it easy,” Gunn said.

  “What a disaster,” Schneider said. “It looks like it’s going to fog up tonight.” He informed Gunn that the computer system had recently gone insane.

  “Yeah,” Gunn said. “That’s not a problem. Tell Barbara to write some lines of code to fix it.” Gunn held out a fistful of wires. “Will you hold this?” he said. The wires trembled; Gunn had developed the shakes from lack of sleep.

  “Have you had something to drink?” Schneider asked, smiling at Gunn’s shakes.

  “Absolutely not. I have been trying for half a fucking hour to solder three wires.”

  Their heads bent toward the tangle. They worked fiendishly. Plumes of breath and burning rosin smoked in the cold air. Suddenly a flashbulb went off nearby. Don Schneider glanced around. A group of schoolchildren had arrived, with their teachers, to view the progress of American science. The children stood behind a wall of glass—a viewing gallery for visitors, which runs along one side of the dome. The purpose of the glass is to prevent human bodies from flooding the dome with warm air, which would warp the mirror, throwing the stars out of focus. Warm air would also ripple out through the viewing slit of the dome at night, thereby causing the stars to twinkle. Astronomers hate twinkling stars, because twinkling throws the stars out of focus. Fortunately the glass wall also prevents visitors from hearing profanity, which is a type of noise that can be heard often enough coming from the cage at the butt of the Hale Telescope.

  “Sun’s going down right on schedule,” Schneider remarked.

  Gunn laughed an edgy laugh.

  They finished splicing wires from the kludge into 4-shooter. Pushing his toe around the floor of the cage, Gunn found a roll of transparent packing tape, the kind that is reinforced with threads of nylon. Palomar Glue. Gunn cut a piece of tape with his knife and taped the kludge firmly to the side of his camera. “Palomar Glue,” he said, “is what holds this place together.”

  In the data room next to the telescope, Maarten Schmidt sat hunched over an oak desk, in a pool of light thrown from a lamp. He was the senior astronomer on the experiment. The Principal Investigator. The boss. “You see James in a controlled panic,” he explained to me. “That is not unusual.” Schmidt was a reserved man, gangly and tall. During his lifetime he had spent around five hundred nights on the Big Eye. He described his role in this experiment as much like that of the manager of a baseball team. His star pitcher—Gunn—appeared to be in trouble. All afternoon Gunn had been rushing around, saying, “Don’t worry, Maart
en, we’re almost ready.” Maarten had begun to wonder if he might have to cancel the experiment that night and use the Hale Telescope for some other purpose. That might delay the search for quasars by six months, a year, who could tell? Schmidt had become used to delays. He had been searching for quasars for twenty-two years.

  Jim Gunn and Don Schneider walked into the data room. Maarten Schmidt said to them, “I think we had better get to dinner.” He added to Gunn, “Are you coming with us, James?”

  “Yes, in a minute.” Gunn crossed the room and sat down at a computer terminal beside Barbara Zimmerman. She was frantically writing computer code that she hoped would operate Gunn’s kludge.

  Maarten Schmidt and Don Schneider took the elevator to the ground floor and emerged from the dome into afternoon sunlight. They followed a trail among cedar trees and withered ferns dotted with old snow. They avoided mentioning quasars. Maarten said to Don, “You never saw my mark-zero flashlight, did you? It dated from 1950. It was an Eveready. Now it seems I have lost it.” A rooster crowed in the distance.

  They descended into a hollow where the Monastery stands, a building where the astronomers visiting Palomar Mountain take their meals and sleep during the day. The Monastery has stucco walls and a gabled roof, and it resembles a summer resort gone a little to seed. Schmidt and Schneider sat down at the single long table in the dining room. Several other astronomers, who were working on other telescopes at the observatory, had already arrived. There was a pile of steaks on the table. Astronomers generally require a massive dinner, because the cold in the unheated domes can grow so bad at night that the only bulwark between the astronomer and hypothermia might be a couple of rib-eye steaks inside the astronomer’s belly and a bag of Oreos in his hand. The astronomers talked quietly, over a clink of china.

  “We’re trying to get 4-shooter to read out at a controllable rate,” Don Schneider said.

  “At what rate?” asked an astronomer.

  “One hundred and forty million bytes per hour,” Schneider said.

  “That’s incredible,” the astronomer said.

  “We should fill twelve tapes a night with data,” Schneider added.

  At the end of the table sat a woman and a man who listened but did not take much part in the conversation. Carolyn Shoemaker had gray hair, cut in bangs, and brown eyes. She wore a maroon sweatshirt and blue jeans. Her husband, Eugene Shoemaker, had a broad face, salt-and-pepper hair, and a clipped mustache. They were a handsome couple. One would imagine them to be normal grandparents, if one did not know that they spent a good deal of their time roaming the Australian outback looking for giant, eroded craters left by asteroids and comets that had smashed into the earth. Gene said, “We’re having all kinds of trouble with our telescope.” He was referring to the eighteen-inch Palomar Schmidt Telescope, which stood in a small dome three hundred yards south of the Hale Telescope.

  “It’s an old telescope,” Carolyn said with affection.

  “One of the guide motors has been stalling on us,” Gene said. “I think the motor’s brushes are shot.” He and Carolyn were on Palomar Mountain to search for asteroids and comets.

  Carolyn said, “Gene has to dive under the telescope and start the motor by hand, before the photograph smears.”

  “I have to move fast,” Gene said. “I have to grab it around the driveshaft and give it a spin.”

  Jim Gunn and Barbara Zimmerman walked in. They sat down and nodded to everyone, and Gunn dragged a steak onto his plate with a fork.

  “That’s not all of it,” Gene Shoemaker went on. “We’ve got some kind of backlash in the main gear. The telescope is jumping all over the place. We can’t hold it on a star.”

  Jim Gunn said, “It sounds like the gears are worn, Gene.”

  “Exactly,” Gene said.

  “There’s the problem,” Jim said. “The gears need a weight on them.”

  “Exactly,” Gene said.

  “Get some rope and a two-by-four,” Jim said. “Lash the two-by-four to the telescope. Then hang a piece of lead on it.”

  Everyone laughed, including Gene Shoemaker. He saw that Gunn actually had a point there, and he reminded himself to bring some pieces of lead with him the next time he and Carolyn visited Palomar Mountain.

  There is a saying among astronomers that five billion people concern themselves with the surface of the earth, and ten thousand with everything else. These people are the practitioners of what is said to be the world’s oldest science. The astronomers conduct their craft from the vantage point of a droplet of iron and silicates orbiting a G2 star that is now drifting at the inner edge of the Orion Arm of the Milky Way. The Milky Way is a spiral galaxy containing approximately one hundred billion suns. If the Milky Way has other names, the astronomers do not know them yet. They have made some progress in the twentieth century, having learned that the Milky Way is a member of what they call the Local Group. The Local Group is a clump of several dozen galaxies, including the Andromeda galaxy and the Clouds of Magellan, that together constitute a virtually unnoticeable knot of galaxies near the outskirts of the Local Supercluster, which is a cloud of many thousands of galaxies. If a galaxy were a leaf, then a supercluster would be the size of a tree. The Local Supercluster amounts to about one-millionth of the observable universe, which throngs with superclusters in the way that a forest is populated with trees. In the more distant parts of the astronomers’ universe—as they see it—the brilliant lights called quasars gleam with a physical power that transcends any forces the astronomers have noticed anywhere near the earth. The astronomers do not fully understand quasars—what they are or how they burn—although many quasars are bright enough to be seen with a modest amateur telescope.

  Maarten Schmidt hardly touched his dinner. He seemed preoccupied. There was a smell of coffee in the air.

  Barbara Zimmerman said to Maarten Schmidt, “I think we’ve gotten Jim’s little box going.”

  Maarten tapped his fingers on the table and turned to Jim. “Well, James, what next?”

  “Keep working, I guess,” Gunn said. He and Zimmerman suddenly stood up and walked out of the room.

  Schmidt laughed. “I didn’t mean that literally!” he called after them.

  At twilight, on a catwalk that encircled the Hale dome, Juan Carrasco and Don Schneider studied the rising fog, which seemed to be pooling in nearby valleys. Don craned his neck, looking up. He said, “What do you think the weather’s going to do, Juan?”

  Juan pointed to the west. He said, “There’s Venus.”

  “I suppose you consider that a good sign.”

  “Oh, yes,” Juan said.

  “This fog is definitely getting worse,” Don said, glancing around. Juan studied a gauge. “The humidity isn’t bad.”

  “That’s if you believe instruments.”

  Juan slapped the wall, feeling for dew. “Tricky,” he said.

  “There’s definitely some structure up there in the atmosphere. Kind of scuzzy,” Don said.

  “High haze can improve the seeing.”

  “Have you ever thought of running for political office, Juan?”

  They walked around to the north side of the dome, traveling clockwise on the catwalk. The fog had drowned the Los Angeles basin but had left the San Gabriel Mountains bare and stark on the horizon. The peeping toads had grown louder, welcoming the fog. There were three other telescopes in operation on Palomar Mountain, apart from the Hale Telescope, and as Juan and Don circled, they could see the dome of each telescope in turn: the forty-eight-inch Schmidt telescope, which was being used to make an atlas of the sky; the eighteen-inch Schmidt telescope, which these days was used mostly by the Shoemakers and other planetary astronomers to search for asteroids that could hit the earth; and the sixty-inch Oscar Mayer Telescope, a general-purpose instrument endowed by the family of the hot-dog baron, because Oscar Mayer had liked stars.

  Juan made up his mind about the fog. “I think we’ll be all right,” he said. Don nodded, went indoors to a red
button located on the inside wall of the dome, and pressed it. The dome shutters began to move open, drawing apart like eyelids, exposing the telescope to the cosmos. A knife-blade of sky appeared overhead, slowly fattening into a crescent speckled with early stars. The Hale Telescope became a network of shadows against the sky.

  The job of the night assistant is to operate the telescope for the astronomer. This not only promotes efficiency but also prevents the astronomer from wrecking the telescope. Given half a chance, an astronomer will cleverly destroy a telescope. For that reason the Palomar night assistants had been given authority over the astronomers in many matters, especially when it came to deciding whether to open or close the dome of the Hale. This was an important decision. For example, a professional astronomer, famished for light, might open the Hale during cold, humid weather. That could let a dew settle on the mirror. The dew could mix with dust on the mirror, which would turn into an acid mud that could etch the glass, thus destroying the mirror in a few hours. The Hale mirror is the size of a living room floor. It weighs fourteen and a half tons. It required fifteen years to make, from the first failed casting in 1934 to the final figuring of the glass in 1949—ground down to a concave dish and polished to a precision of four-millionths of an inch over its entire surface. Four-millionths of an inch is a distance equivalent to splitting the thickness of this page one thousand times.