First Light: The Search for the Edge of the Universe (19 page)

There are asteroids much larger than the Matterhorn traveling on earth-crossing orbits. Sisyphus and Hephaistos, two earth-crossers, are each about six miles in diameter. Either could hit the earth. If either did, the result would be what Gene called a “global catastrophe” to distinguish it from a mere “major event.” The first strong evidence that life on earth might have endured a global catastrophe came in 1980, when Luis and Walter Alvarez and coworkers analyzed an unusual layer of grayish and reddish claystone found near the medieval town of Gubbio, Italy. This claystone dates from about sixty-five million years ago. It is thin—less than an inch thick—but it marks a sharp boundary between beds of rocks below it, containing Cretaceous fossils from the age of dinosaurs, and rocks above it, containing younger Tertiary fossils from the age of mammals. Now known as the K-T boundary layer, it contains abnormally large amounts of rare metals, such as iridium, which are found in much higher abundances in meteorites and comets than in crustal rocks on the earth. The K-T layer has been collected from more than seventy locations everywhere on earth, including the ocean basins. It resembles a coating of paint that was once laid down over the entire planet. The K-T layer also contains microscopic spherules of minerals that may once have been molten glass, shocked mineral grains, and carbon soot. Sixty-five million years ago the sky misted glass, forests on several continents burned, and the planet grew a skin of clay.

The Alvarez group proposed that the impact of a large Apollo asteroid had thrown up enough dust to cause an impact winter,
during which global temperatures dropped for months or years, halting photosynthesis in plants. At roughly the same time at least half of the species on earth vanished, both plants and animals. “If you put that thin layer of clay up in the atmosphere as dust,” Gene remarked, “it wouldn’t let in any more light than a slab of wet clay half an inch thick. The only light at the surface of the earth would have been from luminescent organisms and from fires.” Darkness had triggered the death of much single-celled life in the sea, dynamiting the pyramid of life at its base, causing mass extinctions to ripple upward.

Gene had teamed up with Cesare Emiliani and Eric Kraus to try an idea: that a single projectile, about six miles across, had dropped into the Pacific Ocean. Erupting with the force of a thousand nuclear wars, a shock bubble blew thousands of cubic miles of ocean, atmosphere, and crustal rock into outer space, leaving a hole filling with lava erupting from the earth’s mantle. In one hour a blanket of dust, spreading in free-fall through space, cloaked the earth. The sea returned over the crater as a tidal wave several miles high, which boiled when it hit the lava. The crater might still be preserved in a deep ocean basin—you might find rings on the sea floor. “But we just haven’t explored the oceans that well,” Gene said. The rock and seawater thrown into space came down as mud rains or mud snows over the whole planet, mixed with nitric acid, but a considerable amount of water vapor stayed aloft. Water vapor traps heat from the sun. Global temperatures, after plunging during the time of darkness, bounced upward when the skies cleared. A greenhouse effect had cooked the dinosaurs and turned shallow seas into hot tubs. Small mammals, able to shed heat by virtue of their small bodies, had managed to maintain breeding populations. “That’s one of the ideas you could put into the pot,” Gene said.

Gene’s style as a scientist was to consider the possibilities. When he encountered a promising idea, he felt obliged to try it. By no means had he ruled out the possibility of an intense comet shower. Perhaps a star had passed through the Oort cloud of comets. The Oort cloud would have gone berserk, throwing comets in all directions, some of which would have poured through the solar
system, hitting the earth once in a while, causing stepped or staggered mass extinctions.

Global catastrophes seem to have occurred throughout geologic time. Paleontologists have found evidence for a great dying among the soft-bodied creatures of Precambian times. They have found evidence for two mass extinctions
during
the age of dinosaurs—the first happened at the end of the Triassic period (it may have been caused by the comet or asteroid that made a ringlike puncture in Quebec known as Lake Manicouagan), and the second extinction happened at the end of the Jurassic period. The final extinction of the dinosaurs may have occurred in multiple waves, as if a comet shower had occurred. Or perhaps a giant asteroid had shattered in the Main Belt, injecting a rain of fragments into earth-crossing orbits. During the age of mammals there had been two more horrors, one of them a staggered burst of mass extinctions at the end of the Eocene period.

Biological evolution, it seemed, consisted of periods of stability followed by abrupt developments. After a mass extinction, surviving organisms would branch out, evolving into new forms of life. The evolution of the mammals had been one such explosion, perhaps. The extinction of the dinosaurs might have been heralded by a star shining during the day—a star passing through the Oort cloud—and by an unusual number of comets hanging in the dawns and sunsets, year after year, as the Oort cloud dropped rogue comets, disturbed by the passing star. But if an asteroid had hit the earth, there would have been no warning at all, except the presence of Jupiter in the sky, serene and delicious, and, as always, raking the asteroid belt, flinging asteroids at the earth. If not for Jupiter, perhaps, the dinosaurs might have had time to become slim creatures examining quasars with mirrors, while today we would be balls of fur with no brains and saucer eyes, chewing insects and howling at the night.

“We’ll put you to work tonight,” Carolyn said to me.

“What are we doing?” asked Gene from under the telescope.

“I’m going to teach him how to change film.”

“Good.”

She said to me, “Watch Gene’s time and do the countdown for him when his time is up. This is a four-minute exposure.”

The red numbers on the digital clock hurried along, dividing time into tenths of a second.

“God damn you!” Gene said to the telescope, not to me, and the telescope answered him with a flash of sparks. I heard
zeee, zeee
while he got the crosshairs back on his star. He closed the shutters and rotated the telescope. After some clanking in the dark Gene gave me a film holder containing an exposed cookie of film. I gave him the fresh film holder. Next I had to run to the control desk.

“While Gene is slewing the telescope,” Carolyn said, “you read off the coordinates of his next exposure. Hit the buttons to rotate the dome. Hand him his control paddle. Write down the time, the temperature, the name of the observer, and the relative humidity. Then go downstairs to the darkroom, holding the exposed film holder tight against your chest.” She took me down to the darkroom. “Changing film is quite easy,” she said, switching off the lights. “Turn over the film holder and shake it,” she said. “The film drops into your left hand. Do you feel it? Hold it by the edge. A fingerprint could obscure a comet.” She told me to run my hand along the counter until I found a drawer. The drawer held a lightproof box and a stash of film—the entire night’s work. I had to put the film in the box, close the box and drawer, and load a new film into the film holder, writing the number of the exposure on the film with a pencil. All in total darkness. “Now scurry upstairs,” she said. “I say scurry, because by now the observer—”

“What are you guys doing?” came faintly down the stairs, right on cue.

“Assure the observer that everything’s going fine:
Everything’s going fine, Gene
. It’s like learning how to fly.”

On my first solo I disappeared into the darkroom with a film holder clutched against my chest. I was gone for a long time, leaving Gene stranded on the telescope.

“Hurry up!” the Shoemakers called.

The Shoemakers heard a loud boom in the darkroom. Their night assistant had walked into a wall.

“Everything’s going fine!” I shouted. I had accidentally switched on some blue lights, which I was afraid would expose the film, until I realized that the blue lights were inside my head. I staggered upstairs with a fresh film holder.

“Try to hold it against your chest,” Carolyn reminded me.

“Okay,” I said.

“Did you leave the lights out?”

“Yes.”

“Did you write down the number on the film?”

“What number?”

“The number of the exposure.”

“Which exposure?”

“The one you’re holding.”

“Uh-oh.” I ran downstairs to write the number on the film.

Bangs in the darkroom told the Shoemakers that I was having further navigational problems.

When rotating the dome, the night assistant failed to note the difference between left and right. He could not locate the stop button, causing the dome to spin out of control. Night assistant read aloud a wrong coordinate, causing observer to try to search San Diego for minor planets. Night assistant violently whanged a table, belonging to the California Institute of Technology, with his head. Sounding a note of unwarranted optimism, Gene’s voice came from under the telescope: “Things are shaking down after a bumpy start.”

By the end of the run, the Shoemakers had exposed a total of 144 pairs of photographs. Gene developed them and hung them on lines to dry. “I just know there are Trojans in these fields,” he said, “but Carolyn’s got to find them.” He and Carolyn put the films into glassine bags. The bags went into a box, and the box went into the trunk of the Fury. That evening the Shoemakers and their night assistant drank a small glass of white wine as a toast to the success of planet hunting, and the Shoemakers pointed the Fury at Flagstaff by the light of a waxing moon that told the end of October dark time.

A
ugust had come to Palomar Mountain, bringing a warm wind blowing through ferns and carrasco oaks and around the catwalk of the Hale Telescope’s dome, where a lean figure watched the sun depart. Maarten Schmidt and his quasar team had returned for a run of four nights—their second probe for quasars. In the meanwhile, Don Schneider had been working on a computer program to scan the computer tapes for quasars, but he had not scanned any tapes yet.

Inside the data room, James Gunn, Barbara Zimmerman, and Don Schneider clustered around a computer screen, trying to get the camera on the Hale Telescope to talk to them. The computer screen came to life. It said:
UTILITIES … ROBOTICS … WELCOME TO 4-SHOOTER
.

Zimmerman said to Gunn, “Rewind and erase, Jim.”

Gunn typed to 4-shooter:
REWIND
.

4-shooter said,
OK
.

But 4-shooter was not okay. “The tape goes out to lunch!” Gunn said. He sighed and pulled off his glasses. “What happens to it?”

“How the hell do I know?” said Barbara Zimmerman. “Try
another
rewind. Be sure and check the unit this time.”

REWIND
, Gunn typed again.

OK
, said 4-shooter.

UNIT
? asked Gunn.

10
OK
,
said 4-shooter.

The door of the data room swung inward, and Juan Carrasco entered, holding the box of marinated jalapeños.

“Hi, Juanito,” Gunn said.

“Hello, hello,” Juan said. “Where is Maarten Schmidt?”

“Who?” Don wondered.

Juan smiled. “
Doctor
Maarten Schmidt.”

“Never heard of him,” Don said.

“The tall gentleman.”

“Oh, the tall gentleman. He’s out checking the weather.”

Juan put his box on a shelf, took off his hard hat, and sat at his console. Hitting switches, he started the oil pumps. He powered up a set of controls known as the phantom and the windscreen. He hit a toggle switch. The lights in the room flickered and steadied as a generator kicked in. He tapped a computer keyboard. Seven stories of steel and fourteen tons of flame Pyrex glass—the Hale Telescope—began to move slowly, visible through a window in the data room. “Just checking the weights, Jim,” he said.

Maarten Schmidt entered. “Hallo, Juan. How are you?”

“Fine, Maarten, and yourself?”

“Fine,” Schmidt said. “And the weather is looking agreeable.” Schmidt pulled a circular slide rule from his briefcase. The slide rule was about the same age as Don Schneider. Schmidt called it—in reference to the Hewlett-Packard series of pocket calculators—“my H-P Zero.” Removing his glasses and squinting at the H-P Zero, he began calculating some coordinates for the strip of sky that the team would scan tonight, looking for quasars.

The conversation turned to music.

“Somebody played the Dead Kennedys up here a while ago.”

“You won’t hear any of that stuff when Gunn is around.”

“I bet Gunn has listened to the whole Ring Cycle in prime focus.”

“Eh, probably not all of it,” Gunn said. “Italian opera is very much more preferable. Now the Verdi
Requiem
is the most incredible piece of music ever committed to—”

“Jim’s interest in opera is his only character defect.”

OK
, said 4-shooter.

Don Schneider turned to Juan Carrasco. “We want to open the dome. Is that all right?”

“You may open,” Juan said.

Don went out onto the dome floor. The data room rumbled. Maarten Schmidt watched the window of the data room as the doors of the dome slit drew apart and an amethyst twilight washed
over the Hale Telescope. The telephone rang, and Maarten picked it up. “Two-hundred-inch,” he said, and began a quiet conversation with a colleague.

Don returned and said to the night assistant, “Juan, have you checked the dials?”

“It seems I should put in a correction,” Juan said.

The astronomers were calibrating the telescope and the sensors.

Jim Gunn said, “Let’s go to another star.”

“Moving,” said Juan, hitting toggles, and a high-pitched whine carried through the data room. Dials spun. He said, “We are there.” A bright star came up on the screen.

Gunn’s little blue box, the kludge, still hung from 4-shooter on a piece of tape. Richard Lucinio, the digital wizard, now long recovered from his bad stomach, was rebuilding the computer that controlled 4-shooter, but the little kludge would stay taped to 4-shooter for one more run.

“How ready are we?” Maarten asked, looking around.

“Very ready,” Don said.

“All right,” Maarten said. “Juan!”

Juan hit three toggle switches with three fingers on his left hand, while simultaneously typing instructions to a computer with his right hand. The Big Eye gave off an
oooeee
as it slewed to the part of the sky where the quasar scan would begin. “We are there,” Juan said.

Maarten said, “We have to stop the pumps, gentlemen.” To Juan he added, “Gentlemen, you may stop your pumps.”

“Pumps off,” Juan said. He worked his way down a row of toggle switches. A whine of Vickers pumps died away, and the telescope settled and locked onto its bearings. “Phantom and windscreen off,” he said.

Gunn hit a key to start the transit, and stripes flashed across the video screen. “Uh-oh,” Gunn said.

Maarten peered at the stripes on the screen. “Confound it, James! This is exceedingly strange.”

“4-shooter’s not happy,” said Barbara Zimmerman. “It got hassled.”

Then the screen filled with galaxies.

The astronomers relaxed.

The galaxies were moving upward across the screen. If 4-shooter behaved, then the galaxies would move all night, while the computer recorded a strip of sky that curved in a C-shaped arc through many constellations—a cyclorama of star fields following a line of latitude around the northern pole star. 4-shooter was supposed to scan the strip automatically, without further help from the astronomers. The strip was narrow: a poppy seed held at arm’s length and passed across the sky would trace a strip of similar size.

“Well, that’s it,” Gunn said. “Nothing more to do.”

Don Schneider regarded Gunn with a raised eyebrow, and Gunn regarded Schneider with a grin. Later Don turned to the night assistant. He spoke quietly. “So how’s life been treating you?”

“Very well, Don, and you?” Juan replied.

“Fine. How are Lily and the girls?”

“Fine, thank you, Don.”

“Are you going to take a vacation this summer?”

“We are going to stay with Lily’s mother. She has been very sick.”

“I’m sorry to hear that,” Don said.

Maarten took his glasses off and leaned forward with his nose nearly against the screen, until the light of the video gave his face a bluish tint. “This is fantastic!” he said. “
Things
are going by!”

“Pretty good,” Don said.

“Pretty damned good!” The Principal Investigator was in fine spirits tonight. If 4-shooter kept going, Schmidt might get some quasars.

Don remarked, “We’ve never been able to see one quasar go by.” Quasars were rare, and they looked too much like stars; it would take a computer to find them.

“It would be agreeable to see a quasar,” Maarten said. He was so tall that he could not get comfortable in a chair, and so he stood up and began to walk around the data room. He spun on his heel and said, “This is a crazy kind of observing.”

“Not very astronomer-intensive, is it?” remarked Jim Gunn.

“The normal standard procedure around here,” Maarten said, “is running and screaming. Tonight you could hear a pin drop. If I had a pin, why, I would drop it.” He put a finger on a cloud of galaxies passing by. “These things are going lickerty-snick-bit … 
lickerty-snip-bop.” He turned to Don Schneider: “What’s it you say?”

“Lickety-split,” Don said.

Not long afterward the screen began to blink like an advertising sign, and the astronomers began shouting in frustration.

“Confound it!” cried Maarten.

“What is this?”

“This looks like Las Vegas.”

Gunn held his hands over the keyboard, fighting an urge to tell 4-shooter to quit fooling around. He had learned, however, that every time he interrupted 4-shooter’s scanning with a command, 4-shooter would go dead.

Don said, “We’ll have to get Jim a dummy keyboard, to give him something to play with.”

“That won’t work,” said Barbara Zimmerman. “He can always find a way to lunch the system.”

A rich cluster of galaxies erupted from the bottom of the screen—a pack of elliptical galaxies resembling a scuba diver’s bubbles.

“Wow,” Maarten said dreamily. “All these phenomena. All that stuff floating around out there.”

A barred spiral drifted by. A white needle passed—a spiral galaxy viewed edge-on. A nearby star painted a white cross on the screen—the star had blasted the CCD sensor chip, splashing white rays across the screen. A sparkle of light glimmered. Don Schneider pointed to the sparkle and said that a cosmic ray had hit the sensor chip there. “It was probably a muon,” he said. Faint field galaxies passed, cosmic confetti, wind-driven snow.

Galaxies may or may not be the basic organizational structure in the universe—no one really knows. Perhaps a majority of astronomers today believe that galaxies are
not
the major units of mass in the universe. The dark matter, or missing mass, discovered by Fritz Zwicky might be almost anything. For all anybody knows, the dark matter might include swarms of Jupiter-sized planets. The Milky Way might be stuffed with planets. The dark matter might be comets, or it might be shards of iron. It might be linear defects in spacetime known as cosmic strings. Jim Gunn often referred to the dark matter as “the stuff.” That term suggested how much Jim Gunn knew about the dark matter. One fashionable candidate for the dark matter is
the Wimp. The Wimp is hypothetical. The Wimp might be some kind of Weakly Interacting Massive Particle. Wimps might be able to flow through matter without touching it. Wimps might collect in invisible clouds around galaxies. On the other hand, the stuff, whether it be Wimps or not, might not be connected to galaxies at all. If the immense voids among superclusters contain the dark matter, then no one can say what the dark matter is.

Galaxies dapple the sky more richly than foreground stars in the Milky Way. While all but a few galaxies (Andromeda, the Clouds of Magellan) are invisible to the naked eye, galaxies are apparent to telescopes. The sky is a pointillism of galaxies. The disk of the full moon covers a minimum of twelve thousand galaxies. Among any given field of twelve thousand galaxies there might be—at most—about twenty-five quasars, many of which would be too faint to be detected during a scan. Maarten had estimated that several nights’ worth of scans might possibly yield two deeply redshifted quasars—the remotest ones—or none at all. Scanning for quasars was like rolling dice: the laws of chance came into play, and you never knew what might pop up.

“Well, I’m off,” Barbara Zimmerman said. Once again she had helped Gunn to establish contact with the robots inside his camera. Now Gunn could talk to the robots by himself.

“So long, B. Z.,” Gunn said.

“Drive carefully,” Schmidt said to her. “It’s getting late.”

There was a lull while the astronomers stared at the screen in silence. Juan Carrasco pulled one of several notebooks from his box of marinated jalapeños and made some notes in it. He felt that the only way to begin to guess what was going on inside the Big Eye was to keep track of its vital signs. He felt that the Big Eye had its good nights and its bad nights. On the first day that he had reported to work on Palomar Mountain, he had written on the cover of an empty green notebook: “Love and Ambition are the wings to success. 1969.”

He had been afraid that he would fail—that he would crash the telescope. His old fear still touched him once in a while. He tried not to think too hard about the glass giant, moving out there in the darkness. The green notebook showed signs of much use. He had had to repair it with packing tape, Palomar Glue.

Other notebooks had followed the green notebook. While at first he had stuck to critical information (“astronomers’ favorite radio station: KFAC 92.3 on the dial”), he had also wondered: “What happened at the moment of creation? How did the stars and galaxies come into being? How will the universe end?”—jotting questions for Jim Gunn, hoping that Gunn could answer them. Gunn, however, had been working fiendishly for most of his life to answer these very same questions, without ever attaining satisfactory answers, because (Juan noted) “What we have here is a fundamental problem.”

On a shelf within easy reach, Juan placed a tattered dictionary, and when he heard a savory word, he looked it up to get the nuances. Some of the astronomers seemed to forget that the night assistant was taking notes. When they spoke of their fellow astronomers, he recorded what he had heard:

When the astronomers saw something spectacular on the video screens, he made a note of it for posterity: “Supernova!!!”

He also kept a set of official chronicles in a gigantic red-and-black book of medieval appearance, known as the Observatory Log: “Scattered cirrus, moderate NW wind. Dr. Richard Preston (journalist) 30 yrs. old.”

The box of marinated jalapeños accumulated emergency gear: seven Duracells and two extra flashlight bulbs. Two rolls of tape and some string, which he would lend to astronomers. One fever thermometer (the astronomers were careless about their health, and it was sometimes necessary to take their temperature). One bottle of Campho-Phenique (“Very good for fever blisters,” he said). The marinated jalapeños box also held numerous Polaroid snapshots of beautiful objects: a ring nebula in Cygnus; a pair of nameless interacting galaxies; a comet named 1983d, which will not be seen again by human eyes until the early summer of A.D.
3027. The box held a religious booklet, bearing a message from John Greenleaf Whittier to humanity: “Nothing before, nothing behind: The steps of Faith fall on the seeming void and find the rock beneath.”