First Light: The Search for the Edge of the Universe

by Preston, Richard

  By the end of the next night the astronomers had found five more quasars with deep redshifts. “A couple of years ago,” Don remarked, “I would have gone nuts finding just one of these things. Familiarity breeds contempt.”

  The following night Gunn rebuilt 4-shooter in the garage, working by flashlight. Juan Carrasco noticed a weather front coming in. Maarten spent much time on the catwalk, watching clouds gather. He saw lightning on the horizon, which bothered him. Lightning can contaminate sensors and make it difficult to read the colors of a quasar. As the weather deteriorated, they managed to get another remote quasar. A few minutes before dawn, they shot the last deep suspect, which turned out to be another quasar near the beginning of lookback time. The sun came up, and clouds enveloped the mountain. The team had now turned up nine high-redshift quasars, all of them at the limits of the optically known universe.

  Gunn finished his work with 4-shooter and left for the East Coast. In the afternoon a thick fog covered the mountain. Maarten and Don kept a vigil in the dome, even though the weather was looking poorer all the time. Maarten hunched over a desk, elbows out, in a pool of lamplight. He was wearing his brilliant red shirt. When Bach came on the stereo, he whistled, but he did not whistle for Beethoven. He was sketching something on a piece of yellow graph paper.

  Don stretched out in a chair and tried to read a newspaper. He kept dozing off. (“These older astronomers have a lot more stamina than I do,” he said.) He went up on the catwalk to try to wake up, and he saw that the fog had become bursts of rain. When he returned to the data room, Maarten said, “Come over here, Don. I want to show you something. Look at this.” Maarten placed the paper under the lamp, then said, “I have been fitting our earlier data into these quasars we have just found.” He removed his glasses, took up a pencil, and squinted. “I can put in the last points,” he said, and then he traced the shape of the redshift cutoff.

  “Whoa,” Don said.

  Maarten Schmidt plotted the space density of the quasars over the lifetime of the universe. He started the line at Time Zero. At Time Zero—the creation—there had been no quasars. His pencil traveled horizontally for a while, indicating the passage of the dark time, when apparently no quasars had existed. For roughly one billion years the universe had remained relatively dark while it exfolded in secret. Then Maarten’s pencil line moved upward. The earliest quasars burst across the face of the deep, here and there, each one spreading the luminosity of trillions of suns—gamma rays, X rays, optical light, heat, microwaves, radio—beacons of unearthly color. These were the primeval quasars: the elusive early population, a fossil bed that Maarten had wondered if he might find. Quasars had been scattered thinly at first. Then, during a brief interval of time, Maarten’s pencil line went to the top of the graph—the quasar population exploded and ascended into brilliance. Somewhere around two billion years after the creation, the universe had dazzled with quasars. Maarten’s line crested laterally and started downward in a glide. The quasars peaked out rather slowly. One billion years passed. Maarten’s line dropped faster. The population of quasars collapsed. The line flattened; the quasar population thinned out. Five billion years passed, then ten billion years, and when Maarten’s pencil touched Time Present, the quasars had ceased to exist.

  Don watched the chronicle of first light, feeling the hair on his neck crawl. He had not expected Maarten to try this, even though somewhere in the back of his mind he had known all along that these nine quasars might imply the shape of the redshift cutoff. Something like the following thought crossed his mind: This is the first glimpse.

  Maarten dropped the paper into his briefcase. He felt slightly embarrassed. He began to think that he might have gone too far in drawing the picture. The curve might be wrong. But he could not help showing his sketch to Don. “I was boasting to him,” Maarten would later admit. “Having no high-redshift quasars didn’t tell us much. Once you get some, it is really tempting to make assumptions.”

  They walked down to dinner at the Monastery. When they returned to the dome, Maarten suggested a game of pool. The pool room is a chamber on a lower floor. There, in the old days, on rainy nights, the nabobs among the Palomar astronomers had hunkered down and gambled for nickels. Maarten and Don shot cowboy pool, a game that Milton Humason brought to Palomar, and the only pool game played there by the older astronomers. You rack and break only three balls, and the game switches to billiards at the end. Maarten told Don about his and Corrie’s plans for travel. They did not talk about quasars. On Palomar Mountain it is considered bad form to talk science during a game of cowboy pool.

  The rise and fall of the quasars, as seen by Maarten Schmidt. This curve shows the number of quasars born and burning over time, as the universe evolved. You can see that quasars started to burn when the universe was just a few hundred million years old. After two billion years the universe was rich with quasars, and then they quickly faded away. Now they’ve gone dead, as the graph shows. The quasar called 3C 273 is shown. It’s actually quite close to us in time and space, and yet it seemed a very long way off when Maarten Schmidt first identified its distance, in 1963. (Graph courtesy of Maarten Schmidt, from an article by him in the Journal of the Royal Astronomical Society of Canada, 1993)

  For his part, Don sensed—or believed—that the astronomical community had become concerned that Schmidt, Schneider, and Gunn were not finding any distant quasars. Now he could imagine people saying, “These guys finally got their act together.” Don would later say, “Finding those quasars certainly made the years of frustration worth it. I shouldn’t call it frustration. Nature is the way she is.” He took hard, sloppy shots at the pool game.

  “Our work is finally starting to pay off,” Maarten believed. “We now have a simplistic picture of the redshift cutoff. We have a prospect that we can come up with the real curve in a couple of years. The assumptions in the little drawing that I made for Don are what we are going to investigate.” Nine quasars added up to a hint. A larger sample of quasars might tell the whole story. “It will be of interest to see just how fast the turn-on of quasars happened,” he said. “It seems that the turn-on was not as sharp as we had originally supposed. That will have to come out of a good, solid statistical sample.” He suspected that a quasar might be the birth of the nucleus of a galaxy. If so, then the quasars would be beacons signaling some kind of birth-wave of galaxies. “Quasars may happen in many galaxies,” he said, “but that we don’t know. It depends on the duty cycle of a quasar—how long an individual quasar lasts. We don’t know how long a quasar lasts.”

  His graph had showed the growth and retreat of a forest. A forest could last much longer than a tree. Trees grew and died, the forest waxed or waned. If the core of a galaxy were to go quasar, how long would the blow-off last? Would the galactic core go off like a flashbulb? Or would the quasar burn steadily for a billion years? “If the life span of an individual quasar is brief,” Maarten went on, “then almost every galaxy could have its own quasar. If quasars last a long time, then not every galaxy can have its own quasar.” There were other mysteries. Had the quasars been hidden behind walls of dust in the early universe? Did a quasar begin its existence shrouded in a dust cocoon? Did quasars hatch out of cocoons? Or had the early universe been free of dust, and had the quasars simply brightened rapidly? It seemed that the Hale Telescope had now been pushed as far as it would ever go, at least in sheer distance. As to whether the Hubble Space Telescope might detect any structures or objects beyond the apparent redshift cutoff, nobody could say.

  Now that he could chart the redshift cutoff, he wondered if mapping the far side of an ocean was as important as discovering the ocean in the first place, as he had done two decades ago.

  His feeling brought to mind the words of Robert Louis Stevenson: “It is better to travel hopefully than to arrive.” When the game switched to billiards at the end, he saw that he was far ahead of Don Schneider. He tried to take some goofy shots to let Don catch up, but he accidentally won the game.
Maarten was a reluctantly precise billiard player.

  That characteristic fitted the Maarten Schmidt of Don Schneider’s imagination—a European gentleman who had appeared in Reader’s Digest at Don’s grandmother’s house when Don was eleven years old. When he considered the workings of time, it seemed as though he were living through the happy ending of a book—shooting cowboy pool with Maarten Schmidt, they having become the first two people on earth to glimpse the rise of the quasars. It seemed as believable as life itself.

  For Maarten Schmidt, the best moment of the experiment had actually occurred long ago, when he had first suggested to Jim Gunn that they might throw a net for quasars by scanning a CCD camera across the universe. “That was probably my happiest moment in this work,” he remembered. He had never imagined himself as what he called “technically developed,” and yet he had taught a trick to James E. Gunn. That gave him a greater feeling of satisfaction than having seen the redshift cutoff.

  The Flemish weavers put their stitches into the back side of the cloth. They could not see the true form of their work until they stopped weaving and walked around to the front of the tapestry. Don wondered what people of the future might say about the birth of the quasars. He said, “A hundred years from now, for all we know, somebody may say, ‘These people had it all wrong.’ Nature is always doing something under the rug where you can’t see it. Every generation thinks they have uncovered the last rug. They lift up the rug, and they find another rug underneath.”

  Maarten Schmidt hungered for quasars, and the scanning went on. One night at the Big Eye he walked back and forth in the data room, humming to himself. He fiddled with the contrast on the video screen. “Isn’t that a nice spiral,” he said, touching a drifting galaxy. “Whack,” he said, and gave the galaxy a twist with his finger.

  “Oww!” said James E. Gunn, stirring in a chair.

  “What’s up, James?”

  Gunn glanced at the clock. “It’s four-thirty! Never mind me, Maarten. I can punch a return key with the best of them.” Gunn stood up. He said to me, “You said you wanted to look at the mirror.”

  “What’s going on?” wondered Don Schneider.

  Pulling on his down jacket, Gunn said, “I thought I would take Richard Preston up to the top of the telescope and let him look down on the mirror.”

  Don smiled skeptically. “What are you trying to do, Gunn, get a spectrum of Richard’s head?”

  I followed Gunn inside the dome. He led the way onto the aluminum diving board, the lift that carries people to the top of the telescope. The lift wobbled under the weight of two people. He turned off his flashlight. He punched a button. There was a rumble, and the lift went up along the inside of the Hale dome, while the yoke and horseshoe bearing dropped away into darkness. The lift stopped. We were hovering at the top of the dome, beside the lip of the telescope, and the stars hung close overhead.

  I fumbled with my notebook and pencils. Gunn reminded me not to drop any pencils when I looked down the tube: a pencil falling five stories through the telescope could damage the mirror.

  I walked to the end of the lift, leaned over a railing, and looked into the barrel of the Hale. Then I realized why Gunn had warned me not to drop any pencils. A sheet of stars was hanging a few feet from my face, floating in the mouth of the Hale Telescope. It was an optical illusion. The stars seemed to have been thrown to the top of the telescope, where they were suspended in space. I waved my hand through a veil of stars. The illusion was perfect. It seemed as though if one reached out a hand, one could catch a fistful of stars from the mouth of the Hale. The mirror, far below, seemed to be a flat black void.

  “Nice, isn’t it?” Gunn remarked. “The mirror is projecting an image of the sky into your eyes. Those are real images of stars, as far as your eyes are concerned. Your eyes are cameras. The eye is always a camera, of course, only now it’s a camera on the Hale Telescope.”

  The Hale had magnified the stars and their colors, chryselephantine colors—white, blue-white, and pale gold. At that moment I felt an envy of all astronomers, as well as an envy of the builders of an instrument that could enclose and reimage the creation.

  “Hah, what a fantastic night,” Gunn said. “Arcturus is absolutely steady.” He leaned back, put his elbows on the rail of the lift, and looked up at the sky. His glasses glinted faintly in the starlight. “Astronomy is not terribly important,” he said. He fell silent for a moment, admiring Arcturus. Then he said, “Although it is one of the more important things we do as a species.” He did not see any contradiction there. He said, “Being an astronomer, it’s easy to get a sense of futility about it all. I am afraid we don’t live very long. The species won’t live very long, either.” He gave a kind of sigh. “When one is a child, one doesn’t have a sense of purpose—and that, I suppose, is one of the many extremely good things about being a child. You get a little older and you get a sense of purpose. Young scientists, young people in general, are so terribly serious. They think they know where they are going. We become adults when we decide it’s not so serious, after all.” He paused. “But the sense of wonder never goes away. I guess that’s why I like it up here. It’s seventy feet closer to the stars.”

  “Do you ever dream about this telescope?” I asked him.

  “Oh, yeah. Sure.” He sounded embarrassed. “I dream about it all the time.” He said that he experienced recurrent dreams about the Hale Telescope. “The dreams are always set in prime focus, and I don’t know whether you would call them dreams or nightmares.” He would be sitting on the tractor seat at prime focus and staring down into the mirror through the eyepiece of a camera. “I see a set of red crosshairs with a guide star on them.” He said that he might also hear human voices singing the words “et lux aeterna luceat eis”—“May the eternal light shine on them.” Listening to the voices, he would punch the paddle, trying to get the crosshairs zeroed on his guide star, trying to see something faint and indiscernible in the mirror, one of those things out there. But he was never able to quite see the thing, whatever it was. “What it all means,” he said, “I don’t know.” He turned around and said, “The sky is coming up.” The head of astronomical twilight was creeping over the eastern ridge of Palomar Mountain. “We’d better get down,” he said.

  The lift pulled away and descended. It came to a halt, and Jim Gunn walked onto the floor, moving respectfully beneath the Hale Telescope, covering his flashlight with his hand, because 4-shooter would be taking data until the moment of astronomical dawn.

  And dawn had arrived. Maarten Schmidt took command. He stood behind the night assistant and said, “Regretfully, Juan, you may stop the transit whenever you want.”

  “Starting the pumps,” Juan said. A high-pitched whine ramped up. The telescope floated on Flying Horse telescope oil.

  Don Schneider stood looking at the video screen. “The sky is holding up pretty well,” he said, meaning that he could see galaxies even while twilight took hold. A moment later he said, “We’re losing it.” The mirror caught the dawn and flared, and the galaxies washed away and vanished from the television screens.

  “Take it to zenith,” Maarten said.

  Juan hit the slew switches.

  Don hovered over Juan. “Look at his hands,” Don said. “They’re trembling with fear.”

  “Rock steady!” Juan protested, raising his voice over the rumble of the slew. “We are there,” Juan said.

  “Mirror closed?” asked Maarten.

  “The mirror is closed,” Juan said.

  Don went downstairs to collect the last computer tape of the night. He returned in a moment and placed the tape in the cardboard box.

  “Good night, Juan.”

  “Good night.”

  “See you tomorrow night.”

  The astronomers hurried out of the data room and crossed the summit of Palomar Mountain, following a trail that took them down to the Monastery, where they would sleep all day. This was Don’s favorite moment: threading among cedars in the c
ool light.

  Juan also liked morning. He enjoyed the feeling that civilization had entrusted the Big Eye to him. He took his time putting the Big Eye to sleep. He closed the dome. He inspected an empty glass jar that had recently held a mass of Oreos. He noted the weather in the Observatory Log: “Fog—partly clear, then clear—light NW wind.” He donned his hard hat and stuffed his notebooks into the marinated-jalapeños box and carried the box to his locker. He found a rag in the locker and stepped on the rag. He walked in zigzags underneath the Hale Telescope, holding the rag under his toe, scuffing up the clear puddles of Flying Horse telescope oil that always bled a little from the bearings, a few tablespoons a night.

  He was looking forward to watching the morning news with Lily. They would sit at the kitchen table in their house, and she would ask him how things had gone. “Todo fue bien”—all went well. As his day ended, hers began; she taught school on the mountain. He would sleep through the morning, wake up at noon, maybe cut a little firewood, sleep through the afternoon. The Hale Telescope never appeared in his dreams.

  He left his time card by the door: he had logged eleven hours. He opened the door. The sky had become a transparent blue. He closed the door behind him and stepped into the parking lot. He saw pink in the east, milky fog in the valleys, and a few late stars fading fast. He liked to look into the blue of morning. This was such a beautiful feeling. That clear color in the air told him that he and all the other night assistants and astronomers on Palomar Mountain had been working hard up there last night. Working hard on the sky. He touched the brim of his hard hat and glanced back at the dome, white and round like an ancient temple, while a thought crossed his mind, by no means for the first time, that he was only paying his respects to a temple of science.