First Light: The Search for the Edge of the Universe (24 page)

BOOK: First Light: The Search for the Edge of the Universe
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Down the hall from Maarten’s office in the Robinson building at Caltech, Jesse Greenstein had been working on an article for the
Astrophysical Journal
. Jesse believed that he had found the astonishing secret of a radio star called 3C 48, which was nothing less than this: that 3C 48 was a dwarf star glowing with heavy metals, such as curium, neptunium, and plutonium. One day he
walked into Maarten’s office carrying a bulging manuscript that described his findings. It was forty-one pages long and contained fifteen tables and graphs. “This,” Jesse said, “is the best I can make of 3C 48. If you have any remarks, let me know within a week, and then I’ll send this off.” It hit Maarten’s desk with a heavy sound.

“If I see anything funny, I’ll let you know,” Maarten replied.

On February 5, 1963, Maarten Schmidt got down to business in his office to try to write his article for
Nature
. He placed some leaves of yellow graph paper on his desk (his manuscript paper) and laid out his glass plates of 3C 273. Each plate held a tiny black-and-white stripe, a spectrum. Some of the stripes were only a quarter of an inch long. He had mounted the plates on standard microscope slides with Scotch tape, and now he dusted them lightly with a rather elegantly patterned handkerchief and inserted the slides, one at a time, into a cast-iron microscope. He pulled off his glasses and squinted.

Even in his best spectrum of 3C 273, the features were hard to see. The spectrum clouded the glass like a streak of smoke. The smoke thickened almost imperceptibly, here and there, into broad vertical bands. These bands were the emission lines. Always he worried that he was seeing ghosts. Schmidt could not get over the notion—which had hit him mistakenly, earlier on the mountain—that he was seeing something organized here, something proportional in these lines. The lines fell at decreasing intervals, going from red to blue, as if they were harmonics of an excited atom. He knew also of an invisible infrared line, discovered by J. Beverley Oke, which he could not see in his plates, but he realized that Oke’s invisible line would be spaced regularly with the others. So there would be five regular lines, and two other lines that did not seem regular. Sketching on the graph paper, he tried to construct a model of an atom that might emit harmonics of light. What kind of hot gas could glow in harmonics? “So I got a slight bit frustrated,” he would recall. “ ‘Look here, it
is
regular, isn’t it?’ I said to myself, as it were.”

To satisfy himself that his lines were regular, he decided to check their spacings against the Balmer series of emission lines from glowing hydrogen—the most regularly spaced set of emission lines
known in physics. The Balmer lines were spaced at decreasing intervals. He measured the intervals of the lines in his spectrum, compared them to the Balmer lines, and suddenly he understood. He was
seeing
Balmer lines in the radio star. He was seeing hot, glowing hydrogen in this radio star—except that the colors of hydrogen were pulled far down the spectrum, toward the red end. That would account for five of the lines—all regular. Now, what about the other two lines? If he moved these other two lines back up the scale to normal wavelengths, what would they be? He pulled out his circular slide rule and spun it. Magnesium. Oxygen.

The radio star was made of normal elements. But it was receding from the earth at about 16 percent of the speed of light. This was a Doppler shift. The object was withdrawing in the general expansion of the universe—in the Hubble flow. This wasn’t any star—this was an extragalactic object. A 16 percent redshift would place it around two billion light-years away, among galaxies at the limit of the Hale Telescope’s imaging power—galaxies so faint that when he glanced at one in the mirror with averted vision, he wondered if he was seeing a will-o’-the-wisp. And this object was so bright it had twice burned up a plate.

Schmidt, feeling unable to comprehend the enormity of his discovery, opened his door to let in a little air. At that moment Jesse Greenstein walked past. Maarten said, “Jesse, would you come in for a moment? I want to tell you something.”

Jesse sat down. Maarten told him that he had found an extreme redshift in a radio star.

Jesse’s face went pale. Jesse said, “Oh, my goodness!” A flash of something close to horror crossed his mind at that moment. In an instant Jesse saw that his theory of the radio stars was all wrong. He realized that he had
seen
a redshift in 3C 48! But he had rejected it. Instead he had convinced himself that the thing was a tiny star, drenched with curium, neptunium, and plutonium! He said, “We ought to look at 3C 48.”

They dug up Jesse’s manuscript, and in a few moments Jesse announced that 3C 48 had a redshift of 37 percent. Jesse’s face went into an extreme redshift. He had already mailed his paper to the
Astrophysical Journal
.

In Maarten’s words: “Our eyes were opened.”

3C 48 was departing at more than one-third the speed of light. It would be five billion light-years away—and it was a brilliant point of light! Maarten and Jesse covered a blackboard with calculations. They could not believe what their eyes told them. They groped with chalk for a way to explain these emission lines without resorting to a redshift. They began shouting. The noise brought Bev Oke into Maarten’s office. Schmidt and Greenstein challenged Oke to disprove a redshift in these lines. He could not. Jesse telephoned the
Astrophysical Journal
and asked the editors to suppress his paper. (“It was a fascinating paper,” Jesse would say to me as he recalled these events years later. “Except that it was wrong.”) By 5:30
P.M.
, the universe had grown too strange to be contemplated without a drink. Jesse suggested that they go back to his house. When the three astronomers showed up looking for liquor, Jesse’s wife, Naomi, was flabbergasted. Caltech astronomers never went out drinking on Tuesday nights. “What’s happening?” she asked.

Maarten could not sit on the couch. He walked up and down. If these things—which could no longer be called radio stars—were deep in the universe, then the light they shed equaled the thermal burning of an entire galaxy all at once!—yet crammed into a tiny area, as if some force had crushed a hundred billion stars into a pinpoint and ignited it. And the jet! That jet coming out of 3C 273 looked like a blowtorch flame. The jet would be as long as three galaxies. It was horrible—what kind of force in nature could make a jet of gas three times bigger than a galaxy? “We acted so strange,” Maarten recalled. “We were shouting.” While Maarten seemed almost dismembered from nervousness, Jesse navigated through the wake of “that first terrible afternoon,” as he called it, with the help of Schimmelpenninck cigars (“The Apex of the Dutch Cigar Industry”) and Chivas Regal Scotch whisky. “Let me have some of that, too, please,” Maarten had said, pointing to the whisky. Looking back on it all now, Jesse says, “We had broken through a bubble in which we had been trapped. That is a deep feeling for a scientist. When you are working within a field and a discovery like this happens, the feeling is absolutely incommunicable; it’s organic.”

Maarten drove home. For many hours that night in his living
room, he has recalled, “I paced up and down like a caged tiger.” He was thirty-three years old.

Corrie asked him what was wrong.

He said, “Something terrible happened at the office today.” He told her that he had found an object among the most distant galaxies that burned with a terrifying light. He would have to publish. So little time, and what would he say about it? Walking around the living room, he asked himself, “Are you making a mountain out of an antheap? Or if not, what do you say? Boy, I will have to say something!” He wondered if he was overlooking some simple, innocent, rather ordinary explanation for these emission lines. What a fool he would make of himself if he published an article declaring that a bright star was two billion light-years away! “It all came clear, already, what the future held,” he would later say. “Because if you see very bright objects with such large redshifts, then somewhat fainter ones must have much bigger redshifts.” Maarten and Corrie put the children to bed, but Maarten could not sleep. They had recently bought their first television set. He switched it on and tried to watch a show. He realized that many more of these objects would soon be discovered. They would be fainter, of course, because they would be farther away. The next twenty-five years of his life stood in front of him as a straight road pointing into lookback time, and space opened before him into a gulf that sparkled with remote fires. To search for these things would be to probe down into time, almost into a different universe, and to watch a brutal, inexplicable drama occurring in an alien place. When he saw the test pattern on the television, he went to bed, asking himself, over and over again, Is there a way out?

There was no way out of this universe. Schmidt, Oke, Greenstein, and Matthews (the radio astronomer) scrambled to write a string of papers for
Nature
, which all appeared in a row. Schmidt’s paper came first—“3C 273: A Star-Like Object with Large Redshift.” It was two pages long. There was nothing much to say, really. Nature had turned out not to be complicated and explainable, but uncompromising, simple, and mysterious. Nature offered alibis to no one. These two pages marked a turning point in the history of astronomy, announcing a new heaven spattered with explosive, eerie phenomena—two
pages that were a prologue to two decades of astronomy that would reveal pulsars, accretion disks, black holes, gamma-ray bursters, radio jets, gravitational lenses, and the baroque, inevitable logic of the Big Bang, the moment of creation. When more and more quasars were discovered, and when their deepening redshifts pointed his way into lookback time, Maarten Schmidt came to see that when he had dusted that slide with his handkerchief and stuck it in the microscope, he had accidentally stumbled into a quest known as observational cosmology, whereby one tries to figure out the structure and history of the universe by examining it in a looking glass.

As for Jesse Greenstein, he would soon blow a good deal of money amassing a collection of Japanese Zen paintings. Jesse considered his paintings not exactly a consolation for having let the redshift of the quasars slip through his grasp, but rather a lesson. “I had known that 3C 48 had a redshift,” he said. “And I had thrown that notion out. ‘This is nonsense,’ I said.” He collected paintings that illustrated Zen koans, riddles. One of his favorites shows an old poet riding in a boat, watching geese fly across a cloudy, moon-illuminated sky. The poet is looking up, and one can hardly see his eyes. The riddle is: How does the old poet catch the geese? And the answer is: He has already caught them.

J
im Gunn and Don Schneider were working in the data room, trying to prepare 4-shooter to scan. They hammered at keys, while Maarten Schmidt chatted with Juan. Suddenly Jim and Don shouted, “Oh, no!” and ran out of the room.

“Anything wrong?” Maarten called after them.

No reply.

A printer in the data room started spitting paper. It said:

OK

OK

OK

Maarten contemplated it with a smile.

OK

OK

OK

“It’s saying okay all the time,” Maarten said, “but I don’t think it’s okay.”

OK

OK

OK

Jim and Don raced back into the data room. They pounded keys, trying to soothe 4-shooter.

“I don’t understand a blessed thing of what is going on at the moment,” Maarten said. “Actually it feels quite normal.”

“Now it’s okay,” Jim said, while Don gathered up a mound of coiled computer paper. Maarten hovered over them. He said, “You are boldly going where no man knows what he is doing.”

They persuaded 4-shooter to start scanning, and stars and galaxies
drifted up the screens, but the galaxies looked very different this time. Each galaxy threw out a vertical smear, resembling a candle flame. The screen displayed images of galaxies as seen through flat pieces of glass known as diffraction gratings. Such glasses decompose light, as does a prism. Jim had placed the glasses in front of the four cameras inside 4-shooter, so that the light of every object in the field of view passed through the glass on its way into the camera. This technique smashes apart the light of everything in the telescope’s field of view. The galaxies appeared to be on fire. Each flame was a spectrum emerging vertically from the galaxy. During two nights of scanning, 4-shooter would pass over the same strand of sky twice, taking direct images on the first night, taking images through diffraction gratings on the second night, thereby acquiring pictures of about 120,000 objects along with their broken colors, all of which information would be recorded on tape. Don’s computer would later combine the images to intensify the light, and then automatically search the spectra for emission lines typical of quasars. In that way the team hoped to find quasars.

“We are working!” cried Maarten. He strode to the stereo, and within moments he had found Mozart.

The astronomers gathered around a screen to read the spectra.

“Maarten, look at this,” said Jim, his finger tracing bumps and gaps in a candle flame. “That’s an early M star.” (He later explained to me that an M star is a cool, reddish, aging star.)

Maarten took off his glasses and squinted at it. “Ja,” he said. “A rather blue M-type.”

The sky on the television screen was a mass of blots and smears. Some spectra had dark cuts in them—absorption lines. Others showed swellings—emission lines. The astronomers noticed many M stars. M stars, they said, superficially resembled quasars. “Most of them are pretty close to us,” Schneider said. “Within a few thousand light-years away.” Later he touched the screen. “There’s an emission galaxy,” he said, indicating a bright, violent galaxy with something nasty burning in its core, perhaps a mini-quasar.

“Ah, yes,” Maarten said, tracing the spectrum with his finger. “Look at that. An N galaxy.” He pointed to a bundle of horizontal
spikes in the candle flame. “You can see emission lines, but it is clearly a galaxy and not a quasar,” he said.

These multiple transits on the Big Eye suggested the rhythm of long-distance driving across North America at night. Galaxies sparkled on the video screens like the lights of lonely towns. The talk rose and fell, and often the astronomers stared in silence.

“A carbon line?” Don said, touching another spectrum moving on the screen. “This could be a quasar.”

“For this we need the supercomputer,” Maarten said. He twirled his circular slide rule. “The emission lines on that object are a bit too far apart to be carbon. So I’d say that’s a magnesium break. It’s only an emission galaxy. Sorry, gentlemen.”

Later Maarten said to Jim, “I think it’s about time we saw a quasar go by, James, don’t you?”

“Absolutely.”

“We need to see a quasar,” Don said.

One night the door of the data room swung open, and an astronomer who had been working on the forty-eight-inch Schmidt telescope walked in. “I am really ticked off,” he said. “It’s the second bomber tonight.”

“The second what?” Don asked.

“B-52! Some idiot up there crossed right through my field with a blinking strobe light and all kinds of insanity. He just ruined my plate. I think those guys are vectoring off our domes on night bombing runs.” He leaned over and looked at the screen. “Hey. This is impressive. Have you seen any quasars?”

“We would surely like to,” Gunn said.

“Gunn, this is really impressive. You could sell tickets to this.”

Gunn called to Schmidt, who was on the other side of the room, “Maarten, did you hear that? Who cares about a few spectra when you can get a hundred thousand?”

“Ja, that’s pretty good!”

On another occasion Schmidt, who had been walking restlessly around the room, suddenly whirled on his feet. He had seen something moving on the screen, out of the corner of his eye. “By God,”
he said. He ripped off his glasses. He grabbed a ruler and put it against a spectrum floating up the screen. He pulled out his circular slide rule and twirled it. “Redshift, let me see! Yes! That was a quasar!”

The astronomers’ chairs, which were on wheels, thundered up to the video screen. “That was a bright one,” Gunn said as the quasar disappeared at the top of the screen.

During the past year, Don Schneider had been writing a massive engine of software to find quasars, which, everyone hoped, would find this quasar again. To my eyes the quasar had been indistinguishable from the hordes of spectra splattered across the monitor. Maarten’s reaction reminded me of a fly fisherman, working a slick in a Maine river, who hears an odd, faint skitter of droplets, turns, and, without missing a beat in his cast, drops the fly three feet up-current from the boil of a resting salmon.

A blast of white flooded the screen. “A little tiny star,” Jim mused. “You couldn’t see it with the naked eye.”

Don remarked, “I just hope we don’t cross Orion’s Belt.”

“Say! Which way were we supposed to be going?” Maarten joked.

“Or the moon,” said Juan Carrasco. “Then it would be good-bye screen.”

A cluster of galaxies drifted up the screen, spectra bleeding out of them.

“It looks like those galaxies multiplied,” said Juan.

“It’s the other way around,” Don said. “They eat each other up.”

“Is that right?” said Juan.

Maarten pointed to the screen. “That little galaxy, Juan, is that big one’s lunch for the next billion years.”

“Something terrible happened at the office today.” After Christmas, 1963, at a conference held in Dallas, astronomers argued about the proper name for these quasi-stellar objects. Someone proposed the name Dallas Stars. Someone else thought they should be called Kennedies, in memory of President John F. Kennedy, who had been shot in Dallas the month before. (The term
quasar
finally became official in 1970.) Maarten Schmidt began receiving record amounts of dark time on the Hale Telescope. Sitting alone in prime
focus and zeroing the crosshairs to the music of Bach, Maarten Schmidt broke open the universe.

On April Fool’s Day, 1965, the
Astrophysical Journal
stopped the presses to wait for a letter to the editor from Maarten Schmidt. The letter was no joke. After two years of work he had found five quasars. By a series of tight deductions, he had linked the emission lines of the five quasars into a ladder of logic that had taken him into breathtaking distances. One quasar, he found, was redshifted by 70 percent. Expressed as a ratio, that quasar’s redshift was 0.7. (Astronomers usually express redshift as a ratio rather than as a percentage.) Another quasar had a redshift of 1.03—redshifted by 103 percent. The monster was a quasar called 3C 9, with a redshift of 2.01—an awesome 201 percent—and yet this quasar was bright
blue
in color, because a normally invisible ultraviolet glow in the spectrum, called the Lyman alpha line, had been redshifted down into visible wavelengths, where it tinted the quasar with the color of a pale sapphire.

Astronomers do not know the exact distance from our neck of the woods to a deeply redshifted quasar, because astronomers have not yet been able to link redshift to a distance scale. For example, the quasar 3C 9, with a redshift of 2.01, is probably somewhere between ten and sixteen billion light-years distant from the Milky Way; the photons coming from that quasar are anywhere from two to three and a half times as old as the earth. Maarten once said that he was quite proud of his April Fool’s quasars. By showing that one could find a quasar with a redshift of 2.01, he had tripled the range of the Hale Telescope in all directions from the earth. He had opened up a shell of explorable space that, in terms of volume, was fifty times bigger than the volume of space that had been available to the Hale Telescope before. In a letter to an editor he had enlarged the known volume of the universe fifty times over. “That,” he said, “was the most difficult job I have ever done.”

The news of quasars reached the pages of
Reader’s Digest
in the year 1966, and a copy of that magazine traveled to an old lady who lived on a farm near Heartwell, Nebraska, which was then a hamlet
without a paved street, situated on the high, treeless plains south of the Platte River. Her name was Mrs. Gertrude Schneider. On Sunday afternoons her eleven-year-old grandson, Donnie, used to drop by to visit with her and, incidentally, to read her
Reader’s Digest
. It was at his grandmother’s farm, reading
Reader’s Digest
, that Don Schneider first learned about Maarten Schmidt. He began to feel the presence of quasars over his head. “That was when I gave up dinosaurs for astronomy,” Don says. “It was the last career switch I ever made. By the time I was in sixth grade, I knew that I was going to be an astronomer, at least as much as a child can ever know what he will become.” Don always felt that he had chosen a normal career. “How anyone can go out at night and look up and
not
want to be an astronomer is beyond me.”

When he told his parents that he was going to be an astronomer, they were pleased, because they originally had not had high hopes for Donnie. He had been a slow baby. At the age of three and a half Donnie still had not learned how to talk. They had begun to fear that he was mentally retarded, and they had made plans to send him to a doctor. Then one day Donnie was sitting in his grandmother’s lap while she read a book to him, hoping to encourage him to speak. She pointed to a picture of a barrel and said, “Keg. Can you say that? Keg.”

“Barrel,” Donnie said.

“What?”

“Barrel,” he said, pointing to the word.

“Are you reading this?”

“Yes.”

She flipped the pages, pointing to other words, and he read the words aloud. He had not had anything to say until he could read it first, at three and a half.

Donnie puzzled his mother too. Eileen Schneider taught catechism in Sunday school, and when Donnie was in first grade, he was one of her pupils. She tried to explain to the children what would happen at the end of the world, at the coming of the Son of Man. She read from Matthew: “ ‘The sun shall be darkened and the moon shall not give her light and the stars shall fall from heaven and the powers of heaven shall be moved.…’ ”

BOOK: First Light: The Search for the Edge of the Universe
10.69Mb size Format: txt, pdf, ePub
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