First Light: The Search for the Edge of the Universe

by Richard Preston

  The news of what Gunn was doing underneath Caltech must have filtered into the scientific community, because shortly before he finished 4-shooter, Gunn received a telephone call from the John D. and Catherine T. MacArthur Foundation, informing him that he had won a MacArthur Fellowship—one of the so-called genius awards. Gunn would collect a slug of money totaling $220,000 over the next five years, which he could spend any way he pleased. He immediately telephoned his wife, who happened to be on a run at a radio telescope.

  “Oh, Jim!” she said. “We can get a box at the Met!”

  “This is serious.”

  “That’s what I’m talking about,” Jill said.

  A box at the Metropolitan Opera seemed a bit extravagant for a couple of astronomers, but they did buy season tickets. Apart from that, Gunn could not figure out how to spend the money. He bought a laser-disk video player in order to watch opera at home, and he wired it into his homemade stereo. He gave some money to graduate students to help them with their travel. The rest of the money is sitting in a bank account. He might have invested some of it in a good pair of prescription reading glasses, but, in his words, “They are tremendously expensive.” He enlarged his Woolworth collection.

  Maarten Schmidt had been watching Gunn from afar. Although trained in classical photography, Schmidt was not unaware of this person who could build an extragalactic camera from out-of-the-Dumpster parts. By the time Gunn had finished building Pfooey, Schmidt wanted to get a collaboration going with Gunn, but then so did a lot of other people. Schmidt had his own reasons.

  In 1967, Schmidt had discovered that as one looks out into space the universe appears to become thickly settled with quasars. He showed that quasars were a pathological aspect of the young universe and are now largely extinct. He wanted to collect a small but carefully selected sample of quasars, in order to understand the characteristics of quasars as a population, in much the way that one would sample the opinions of a few people in order to understand the mood of a nation. Working with a colleague named Richard Green, Schmidt directed a long survey for quasars, using the eighteen-inch Schmidt telescope on Palomar Mountain. Green eventually found ninety-four quasars. When he and Schmidt analyzed their data, they discovered that the population of brightest quasars had burned out sharply and abruptly as the universe evolved, while the less brilliant quasars had malingered. But the Little Eye could not pick up quasars with deep redshifts. Schmidt wondered just how many deeply redshifted quasars might be hidden among the stars.

  Schmidt and other quasar hunters had noticed that quasars seemed difficult to find at great distances, at enormous lookback times. They sensed a falling off. As they explored deeper, they found fewer and fewer quasars, and the redshifts trailed off: 2.69 … 2.75 … 2.88 … 3.40 … 3.78. In 1987, a team found a quasar with a redshift of 4.43, which corresponded to a rough distance (only guessed) of thirteen billion light-years. “You must have perceived a slowing down,” Maarten said to me on the catwalk one night. “Why don’t we see quasars with redshifts of five, six, or seven?” Watching astronomers trying to discover the most distant quasar was like watching javelin throwers trying to break a world record; the javelins were landing close together, approaching a natural limit. Astronomers began to feel that they were looking through a veil of quasars into darkness—into the edge of the universe. The redshift cutoff.

  An astronomer named Patrick Osmer found the first scientifically clear evidence that, as he looked past a redshift of 3.5, he had seen the redshift cutoff begin. But the fine structure of the redshift cutoff remained an enigma. Some astronomers suspected that only the Hubble Space Telescope would be powerful enough to probe to the edge of the universe and thereby to define how and when quasars caught fire. But to reach the redshift cutoff with the Hale Telescope would, for Maarten Schmidt, conclude an odyssey into lookback time that had begun accidentally one afternoon in 1963, when he had dusted a little glass slide with a handkerchief and put it into a microscope.

  In 1982, Schmidt asked Gunn rather casually if Gunn might be interested in using Pfooey to map the outer structure of the universe. Gunn thought that sounded like a nice idea. Schmidt immediately pulled Don Schneider into the experiment; Don was then Schmidt’s assistant. Schmidt, Schneider, and Gunn began their search by taking more than one hundred electronic snapshots through a prism installed in Pfooey. These snapshots revealed some quasars, but none were particularly near the edge of the universe. Schmidt became restless. The Pfooey snapshots did not cover much sky. He began to think about dramatic solutions. One night when they were taking snapshots, Maarten asked Jim if Pfooey could be turned into a scanner and swept across the sky.

  “That was obviously a big job,” Maarten would recall, “because Jim had to think about my question for five minutes.”

  Jim put his hands over his face. He ran Pfooey’s control program through his memory. He took his hands from his face and said, “Yes, Maarten, we can do it.”

  Merely by changing a few lines of computer code, Gunn turned Pfooey into a scanner, which worked fairly well, except that every time a bright star passed across Pfooey’s sensor chip, it sent electrons caroming like golf balls through Pfooey, which was a pain. The astronomers found a few quasars, but the highest redshift came to only 2.76. A decade ago that would have been a satisfying redshift, but today it was a disappointment. They felt sure that their technique had been good—they had not found any remote quasars simply because such quasars were extremely rare. This surprised them. They concluded, tentatively, that the redshift cutoff was nearby and abrupt; and that therefore the population of quasars had been born suddenly and rather late in the development of the universe. But Schmidt had his doubts about all this. He wondered if there might be a hidden population of quasars buried deep within lookback time, near the beginning of all things. When Gunn finished building 4-shooter, Schmidt asked Gunn if he would not mind turning 4-shooter into a scanner, since with a quartet of cameras it could devour sky. Schmidt felt like a paleontologist walking through a dessicated African valley, sensing the presence of fossil beds under his feet that might hold teeth and skull fragments of missing links and half-imagined creatures; but whether luck and his tools and his hopes would serve him well or not at all, he could not say or know. The edge of the universe haunted Maarten Schmidt, and he now felt that he no longer understood the redshift cutoff at all.

  PART 4

  Discoveries

  Richard Lucinio liked to find reasons to drop by Palomar Mountain. He showed up on Palomar at two o’clock one morning, obviously traveling on business, because he was carrying an attaché case. He stood in front of a video screen, watching a river of galaxies slide past, and said, “Gunn, I have never seen anything like this. Those things are like grains of sand out there.”

  “There are lots of areas of the universe that look like this,” Gunn said casually. “Places where the sky is covered with galaxies. But just because you see beaucoup galaxies in one place and only a few galaxies in the next place, it doesn’t mean that that’s a large perturbation in the structure of the universe.”

  After reflecting on this, the digital wizard went into a small workshop next to the data room, carrying the attaché case. His two dogs followed him. He opened the attaché case, and there was a computer inside it—keyboard, chips, illuminated display. A smell of burning solder drifted through the data room. “A wizard’s work,” Lucinio said, “is never done.” He said that the attaché case was an emergency control system for 4-shooter. “I can hook this thing into 4-shooter and run all the robotics with it,” he said. His dogs grew bored and wandered around the data room. One dog fell asleep underneath the table that held the main video screen. He had a dream, and his paw pads wobbled. He thought he was running.

  One evening Jim and Maarten got into a discussion about television. Most of the TV programs that Jim watched were videos from the Hale Telescope. Maarten, on the other hand, enjoyed late-night television—it helped to clear the quasars from his mind. “I don�
��t imagine you saw the World Wrestling Federation tournaments, James?” he wondered.

  “What?” Gunn said.

  “They were last week. On late-night television.”

  “I am afraid I missed that, Maarten.”

  “That’s too bad. There was this free-for-all. It was involving these exceedingly terrible guys, this motorcycle gang. They seemed to be hitting everybody with chains, including the referees. It was just incredible. Then you should have seen what happened to—what do they call this guy? Ja! Hulk Hogan! This other guy—I mean, this really enormous fat guy—got mad at Hulk Hogan. You could see him getting madder and madder, and then he ran across the ring and just fell on top of this Hogan, rendering him unconscious, as it were. After that they showed him being loaded into an ambulance—”

  “Why do you watch that stuff, Maarten?” Jim asked.

  “It helps me get to sleep.”

  “I don’t see how.”

  “Part of the problem is that the television seems exceedingly difficult to turn off.”

  “There’s a switch on it, Maarten.”

  “That’s too much trouble.”

  “There’s also a plug on the wall.”

  “Ja, but who wants to get out of bed for that?”

  To pass the time while they watched galaxies, Gunn and Schneider held science-fiction quizzes.

  “ ‘The planets you may one day possess,’ Don quoted, ‘but the stars are not for Man.’ Who said that?”

  “ ‘The stars are not for Man.’ I know that line,” Gunn said. He walked back and forth. “Karellen. Karellen said that, in Childhood’s End. By Arthur C. Clarke. One of the best science-fiction books ever written.”

  “Yes. It had to be Karellen,” Don said, “because he was the only one who talked of deep motives—and he was the alien. But Dune is the best science-fiction book ever written.”

  “No, no, Don, Childhood’s End.”

  “I agree with you that Childhood’s End is a great book,” Don said. “But ‘The stars are not for Man’—those are the saddest words I have ever read. And do you remember these words: ‘Yes, we have had our failures’?”

  Gunn paced the room with his hands in his pockets. He was wearing his standard eyeglasses, the pair with electrical tape around the nosepiece. His down jacket piled up in a sort of hunch over his back. “Sure!” he said. “That was also Karellen!”

  Juan Carrasco, who generally listened to such discussions without comment, smiled and said, “ ‘We have had our failures.’ I like that.” The astronomers grinned at the night assistant and said nothing. Yes, Juan had seen them all.

  I asked Gunn one night, “Do you think there is life in these galaxies—somebody out there scanning the Milky Way?”

  “Well …” A gleam entered his eye. Glancing at Don Schneider, Gunn said, “Maybe not in every galaxy. Maybe somebody in every third galaxy is looking at us.”

  Don Schneider turned a level look on Jim Gunn. Don was shocked, or professed to be, because he didn’t believe in the existence of intelligent life out there. With a honed edge in his voice Don said, “It’s amazing, Jim, to think that we really are alone in this big universe.”

  It was Gunn’s turn to be shocked. “Why, Donz! Don’t you believe it for a moment!”

  “I am a scientist. I believe evidence. I will believe any evidence you care to show me regarding the existence of aliens.”

  “Evidence! All the evidence to show there is no intelligent life out there amounts to absolutely nothing.”

  “I have locked onto a debating shyster,” Don said.

  “It is amazing, Don, to think how crowded this universe is.”

  “I am ready to be convinced.”

  “You will.”

  “When?” Don demanded.

  Jim Gunn did not answer. He smiled archly and sipped a Von’s Lemon-Lime soda.

  Don turned to the night assistant for support. “You see, Juan, as with all my debating activities, my opponents just turn their backs, crushed in utter defeat, yet affording me no satisfaction whatever.”

  “Yes,” the night assistant agreed, “that is depressing.”

  Gunn said, “The number of civilizations out there is—”

  “Zero,” Don interrupted.

  “Infinity.”

  “Well, the answer is one of the two,” Don said, abruptly sounding less certain of himself. He said, “Have you seen that Twilight Zone, ‘To Serve Man?”

  “Terrific story,” Jim said. “I read it.”

  “Well, then.”

  “Well, what, Donz?”

  “Well, as you know, the aliens came to earth, and they brought a book with them. Do you remember the title of that book, Jim? To Serve Man. Everybody was so happy about that. Then doubtless you remember what happened.” Don gave a rather involved plot summary, the punch line being that To Serve Man had been a cookbook.

  Gunn did not reply.

  “Also,” Don asked, “where is everybody?”

  Gunn nodded toward the screen. “Right there.”

  Don said, “You have to admit that my point of view is equally defensible.”

  Don Schneider was a devout Roman Catholic, and he preferred to think of the human species as a chosen people, and space as the final frontier. He believed that humanity was slowly readying itself for what many people involved in astronomy felt was the inevitable step. They called it the Breakout—that we would reach for the stars, not with a mirror but a ship. “Space,” he said, “is our manifest destiny.” What bothered him was the thought that if alien civilizations existed, then some of them would have advanced a few billion years ahead of us. One billion years amounted to four rotations of a galaxy, four galactic years. Homo sapiens had lasted, so far, for just forty minutes out of a galactic year, whereas a culture two billion years ahead of us would be eight galactic years old. “Powerful cultures,” he said, “always destroy less technologically advanced cultures. When the Europeans landed in North America, they were only a few thousand years ahead of the Indians, and look what happened to the Indians.” Don believed that a contact with aliens might be the greatest danger we would ever face. A global nuclear war or a plague from a hot virus would kill a lot of people but would not be likely to kill the human spirit. He felt that even to believe in the existence of alien civilizations would be to erase the purpose of his life as a scientist. A two-billion-year-old culture would be four times as distant from us in time as we are from the trilobites. If there was somebody out there, what would they care for the ambition of a slime mold?

  Gunn, for his part, wondered what he would do if a civilization offered him two billion years’ worth of science. He imagined that knowledge as a symbolic language written in a book—a book with all the answers in it. “Would I open that book?” he wondered out loud. “I don’t think I would open it. Well, I would not be able to resist the temptation. We would read it, but we would not understand it, although we would know it was written by somebody who did understand, and that would kill us.”

  Maarten remained silent during the alien debates. He preferred to stick to conservative questions that he thought he could answer with a telescope, such as that of the unpublished history of the universe.

  One night the astronomers were watching spectra float up the screen, the way one likes to stand on a bridge over a lazy stream and observe different shapes and species of leaves drift by on the water, while Juan Carrasco was watching the temperature of the mirror. He said abruptly, “The humidity is going up.” He was worried that a dew might fall on the mirror.

  The astronomers came over to Juan’s instruments.

  Maarten said, “We are barely over the dewpoint.” A warning light began to blink. Maarten said, “Those numbers are falling like crazy.” A buzzer went off. “We have to close,” Maarten said.

  Juan threw a switch. “Mirror closed.”

  The galaxies snuffed out.

  Juan climbed to the catwalk. He saw a narrow moon. He extended his arm and placed his thumb ov
er the moon. A glory of faint cirrus clouds haloed his thumb. He slapped the outside wall of the dome. It felt wet and cold. He returned to the data room and announced that the sky held structure. The astronomers talked and decided that the clouds would last. In that case, Juan said, the astronomers could find him downstairs. Pulling a ring-binder notebook from a shelf, he said, “I am going to do motor inventory.”

  The Palomar engineers were attempting to “characterize” the Hale Telescope, which is another way of saying that they were trying to figure out how it worked. Juan had been given the assignment of locating every motor in the dome. The ring-binder notebook contained a long list of motors. “It is my job,” he explained to me, “to determine which of these motors exist.” He pulled on a pair of rubber boots and took the elevator down one level. I followed him. We crossed a walkway and arrived at a set of electric pumps that drove oil up into the telescope.

  We were deep in the bowels of the dome. He turned on his flashlight and pointed it around, into dim areas, across cabinets covered with dials and racks full of radio tubes. This was the graveyard of instruments. When a gadgeteer’s machine had outlived its usefulness, the astronomers left it there to collect dust and possibly to serve as a source of parts. Someday 4-shooter would be sitting here. Juan consulted his notebook. He stepped into a drip pan that contained puddles of Flying Horse telescope oil. He said that during motor inventory, he might find that a motor listed in the blueprints had never been built. Or he might discover a mystery motor that had been running calmly since Harry Truman was president. He bent over and read a serial number on a motor. “That checks out,” he said. He walked around, poking at things. He said, “I have found five Vickers pumps here, but there are supposed to be six. I can’t locate the sixth pump. It may not be here at all. There is some confusion about what exists in this telescope and what does not exist.” He touched the brim of his hard hat and pointed his flashlight around.