The Man on the Mountain
(See Cover).
Some 30 evenings a year, Astronomer Maarten Schmidt, 36, struggles with an electrically heated flight suit and enters the great, silvery dome of California's Mount Palomar Observatory. There, his tall, gangling frame seems suddenly reduced to Lilliputian proportions by the mammoth, 200-in. telescope that towers above him. An elevator hauls him slowly to a cylindrical observer's cage inside the telescope itself, and the dome's curved doors slide open to the cold mountain air. Perched high above the observatory floor, with classical music from an all-night Los Angeles radio station in the background, he checks his instruments, loads a camera and settles down to his lonely vigil.
Until 5:30 the next morning he stays on the alert for clouds that might obscure the image on his photographic plate or for a sudden movement that could blur it. He nurses his equipment fastidiously as the world's largest telescope swings slowly across the sky, tracking the elusive targets that astronomers call quasars. They are the most distant objects ever seen by man.
By analyzing faint quasar light that traveled billions of years before reaching telescope mirror and camera, Schmidt has uncovered clues to the ancient secrets of the universe. The remote and starlike objects he studies were born, and may have died, long before the earth existed. By decoding some of their signals that have been so long in transit, the Dutch-born astronomer has upset the familar pre-quasar universe of stars and galaxies. He has rocked the worlds of astronomy, physics and philosophy. He has undermined established theories and stimulated fantastic new ones, provoked scientists into bitter controversies and brilliant hypotheses. The cosmic questions that Schmidt's observations have raised reach far beyond mere manned landings on the moon, or even the search for life on nearby planets.
Did the universe have a true beginning? Did it start with a great primeval bang, and has it always been expanding? Or has it existed forever, essentially the same, its galaxies drifting apart while others are born to fill the space between, so that the words "eternity" and "infinity" maintain their literal meaning in an unending past and future? Somewhere out in the vast reaches of space and time, there are sources of energy as yet unimagined by man--unbridled physical reactions that dwarf any conceivable nuclear explosion?
Signals from Space. The distant starlike objects not only pose the questions, they promise the answers. Merely finding them in the first place -- detecting their radio voices and photographing their odd and telltale light-- was a cooperative triumph of radio and optical astronomy. It was Schmidt who discovered the enigmatic properties of the quasars.
A significant step toward this discovery occurred in 1931 when Radio Engineer Karl Jansky of the Bell Tek phone Laboratories accidentally found that radio signals were coming from outer space. But astronomers were slow to recognize that such radio energy--the only radiation besides visible light that can penetrate the earth's atmosphere over a wide frequency range--might offer a powerful new tool for exploring the universe. Little was done to take advantage of the new tool until wartime radar research provided accurate directional antennas and improved electronic techniques.
Immediately after World War II, astronomers all over the world hastened to build steel-ribbed parabolic dishes and ungainly rows of spindly antenna arrays. They even lined a small valley with wire mesh and began to scan the skies for radio sources. These pioneer radio astronomers scanning the sky "saw" only blotchy, vague shapes--like street lights dimly seen through the fog.
To sharpen their vision, they began building larger antennas. In 1946, they devised a new technique: radio interferometry, in which two antennas located at a considerable distance from each other are tuned to radio signals from a single source. Because the radio waves arrive at the antennas at slightly different times, they interfere with each other in a pattern that more sharply defines the position of the source.
Gradually, as the accuracy of radio telescopes improved, the vague shapes in the sky contracted until it became possible for radio observers to direct optical astronomers to smaller and more manageable areas. In 1949, astronomers using these directions spotted the first visible object outside the solar system that was associated with a discrete radio source: the Crab Nebula, the remnant of a star explosion (or supernova) in the earth's Milky Way galaxy. Shortly afterward, they identified the first visible source outside the Milky Way: a large galaxy 50 million lightyears* from earth. In the next decade, as radio and optical astronomy continued their fruitful alliance, about 100 additional galaxies and supernovas were recognized as powerful radio transmitters.
Intimate Secrets. Mystery remained. When optical astronomers turned their huge glass eyes on some of the areas of sky manned by radio astronomers as sources of powerful emissions, they found only assortments of faint, nondescript stars. Then, in 1960, aided by pinpoint data supplied by Cambridge University's radio astronomers, and Caltech's Owens Valley Observatory, Caltech astronomers discovered that one stream of powerful signals was coming from what appeared to be a small, faint star. During the next few years, as radio telescopes continued to supply increasingly precise data, the California astronomers discovered three more faint, mysterious objects. Though they were undistinguished in appearance, they stood out like powerful beacons in the radio sky. For want of a more descriptive term, the objects came to be called "quasi-stellar sources," a name that was quickly contracted to "quasars," and reluctantly adopted by astronomers.
Now, the optical astronomers turned to one of their most powerful tools: the spectrograph, which separates light into its component wave lengths by passing it through a prism or a series of fine lines etched on a glass plate. The spectrum of colors that results can be photographed and interpreted by scientists to reveal the secrets of the light's source.
Superimposed on a rainbow of colors ranging from short-wave-length violet light at one end to longer-wave-length red at the other, star spectra show a series of characteristic bright and dark vertical lines that indicate the presence of specific chemical elements. In 1868, one such line in a spectrogram of the sun enabled British Astronomer Norman Lockyer to detect the existence of a new element--helium--before it was discovered on the earth.
Using the 200-in. giant at Palomar, Astronomers Allan Sandage and Jesse Greenstein channeled the faint light from a quasar through spectrographs, using exposures as long as six or seven hours to produce a usuable image on their film. Their painstaking labor produced tiny spectrograms that contained no color, only shadings of black and white, and were one-third of an inch long and a thousandth of an inch thick. Under the microscope, however, Sandage and Greenstein were barely able to discern strange patterns and spectral lines that had never before been observed in stellar spectra. Genuinely puzzled, Greenstein began to work out an elaborate hypothesis suggesting that the quasars were extremely dense and hot nearby objects, probably the remnants of supernovas containing highly excited or unfamiliar elements.
Strange Lines. In 1962, a group of radio astronomers led by Cyril Hazard tried a subtle tactic in an effort to pinpoint a strong radio source that searchers with optical telescopes could not identify. Pointing the Parkes, Australia, 210-ft. dish antenna toward the source, known only as 3C 273,* Hazard's group recorded the precise time that its signals were eclipsed, or blotted out, by the sharp leading edge of the passing moon and the time when they reappeared from behind its trailing rim. Because the position of the moon can be accurately calculated for any given time, the Australians' "lunar occultation gave them an accurate position of the elusive radio source.
When the Australian data reached Astronomer Maarten Schmidt late in 1962, he was able to locate 3C 273 in earlier photographs, which revealed it to be a round, fuzzy, starlike object with a faint, glowing jet protruding from it; he had discovered a quasar that was brighter than any yet recorded by his colleagues.
Soon after, he obtained a good spectrum from the quasar and, like his colleagues Sandage and Greenstein, he was puzzled by the sight of unfamilar spectral lines. But after staring at the spectrum for six weeks, Schmidt had a wild, almost desperate thought. Three closely spaced spectral lines on his photographic plate resembled hydrogen lines. But they were not in the blue segment of the spectrum where they belonged: they were superimposed on the red portion instead. Could they actually be hydrogen lines that had shifted to longer wave lengths?
If 3C 273 was racing away from earth, Schmidt realized, the wave length of its light would be lengthened -- just as the wave length of sound from a train's whistle lengthens (thereby dropping in pitch) as it speeds away from a listener at the railroad station. Such an effect on light is known to astronomers as a "red shift" because it moves the characteristic lines of spectral light toward the red, longer wave length end of the spectrum.
The effect had already been observed in light from distant galaxies, which are receding from the earth as well as from each other. Furthermore, according to a law described by Astronomer Edwin Hubble in 1929 (and never successfully challenged since), the greater the red shift in a galaxy's spectrum, the faster the galaxy is speeding away, and the further it is out in space.
State of Shock. Acting on his hunch, Schmidt assumed that the lines he saw were really hydrogen lines. He measured the shift and calculated that 3C 273 was moving away at 15% of the speed of light, or about 28,000 miles per second. This meant, according to Hubble's law, that the quasar must be about 1.5 billion light-years from the earth, instead of being a faint, nearby star -- as most astronomers had assumed.
The more Schmidt calculated, the more problems he raised. Even a very bright galaxy consisting of billions of stars would be much dimmer at this distance, but starlike 3C 273 can be seen easily with a 6-in. telescope. Clearly, more study was needed.
The strongest of hydrogen's lines, called H-alpha, seemed to be missing entirely from 3C 273's spectrum. If Schmidt's theory was right, the line was not missing but had shifted into the infar-red region of the spectrum, where it would not register on an ordinary photographic plate. Schmidt remembered Astronomer Beverley Oke had already studied the spectrum with an electronic gadget sensitive to invisible infrared. Oke had found a prominent line precisely where Schmidt thought that H-alpha should be, shifted into the infrared. 3C 273 was moving faster than seemed possible; it was farther away than anyone had been prepared to believe, and it was brighter than it should be. Schmidt recalls that he "was in a state of complete shock."
When Schmidt's interpretation and Oke's proof were published in Nature, the world of science also went into a state of shock. Astronomer Greenstein promptly shelved his own unpublished quasar theory, admitting that "if it weren't for Maarten, I could have been caught with my scientific trousers down." Instead, he turned to a spectrogram that he had taken from quasar 3C 48 and -- using Schmidt's redshift key -- discovered that 3C 48 was re ceding even faster than 3C 273. By Hubble's law it appeared to be some 4 billion light-years away.
Ultimate Truths. The astonishing distances and speeds proved particularly provocative to cosmologists, who deal with such heady subjects as the history and nature of the universe. More than any other scientists, they are keenly aware that when they look into the night skies they are looking into the past. Because light travels at a swift but finite speed, the sun is seen as it was eight minutes ago, the nearest star as it was four years ago, and the near est galaxy as it appeared 2,000,000 years ago. If Maarten Schmidt and his colleagues were correct, they were seeing quasars as they looked billions of years ago. This long-range view seemed to provide a prime tool for testing cosmological theories about the origins of the universe.
P: STEADY-STATE theorists, led by British Astronomer Fred Hoyle, claim that the universe has always existed, has always been expanding and has looked the same at any point in time. As the galaxies move farther away from each other, steady-staters believe, new galaxies are constantly being formed out of hydrogen that is created and fill the gaps, keeping the expanding universe at a constant density.
P: BIG-BANG believers, including Cambridge University Radio Astronomer Martin Ryle, think that the universe began about 10 billion years ago in an incredibly huge explosion of densely packed matter. Some big-bangers feel that the fragments of that explosion--now galaxies--will continue to move outward and away from each other forever, like spots on the surface of an expanding balloon. Others suggest that the gravitational attraction between the galaxies will eventually overcome their outward motion, pulling them all back together in a cataclysmic collision that will end the universe.
P: OSCILLATING-universe proponents, such as Astronomer Allan Sandage of Mount Wilson and Palomar Observatories, lean toward the concept of a universe that expands after a big bang, contracts to an extremely dense state, and then explodes outward again in an 80-billion-year, never-ending cycle. In one sense that universe, like the steady-state universe, is infinite. Instead of being completely destroyed, it expands again after each contraction. It has been about 10 billion years since the last big bang, Sandage speculates, and only 70 billion years remain before the galaxies crush together again to start the next cycle.
Of the three theories, the steady state seems to have been dealt the most severe blow by studies of the 30 quasars whose red shifts have been determined so far. Because the number of quasars at greater distances--and thus further back in time--appears to be larger, quasars seem to have been more numerous when the universe was younger. And they seem to have disappeared as the universe evolved--a direct contradiction of the major feature of the steady-state universe. In addition, quasars, as calculated by their red shifts, are gradually slowing down, a phenomenon that can be explained by the mathematics of the big-bang and oscillating universes--but not by the equations of the steady state.
To meet the challenges, the resilient Hoyle has proposed a steady-state variation. In his steadily expanding universe, there could be "bubbles" in which expansion or contraction sometimes takes place. The earth just happens to be in one of the expanding bubbles, he suggests, which accounts for the disturbing quasar observations.
Mere Peanuts. Quasars have actually presented a greater challenge to physicists, who have been working overtime to deal with the implications of Schmidt's discoveries. How can such relatively small bodies generate enough light to be seen billions of light-years away? Where did the energy come from? Early observations suggested that the quasars were only a fifth or as little as a hundredth the size of an average galaxy, which is about 100,000 light-years in diameter. Yet the quasars' light is as much as 100 times more brilliant than light from an ordinary galaxy--despite all of its 100 billion glowing stars--that is the same distance away.
Particularly perplexing is the fact that the light output of many quasars has been observed to vary over cycles as short as three months. To some astron omers, this means that some of the quasars may be as small as 90 light-days in diameter--a distance of 1.5 trillion miles, which is mere peanuts by cosmological standards. If these quasars were much larger, the light and radio waves from various parts of them would arrive at the earth at different times, smearing out the variation and making it unobservable.
The necessity of explaining the prodigious outpouring of energy from such small bodies has generated some fantastic intellectual inventions, some of which may yet turn out to be accurate. Fred Hoyle and a California Institute of Technology colleague, William Fowler, have suggested that quasars might well be massive superstars whose nuclear fires have died down because of the depletion of their hydrogen fuel. Such stars, they say, would begin to collapse, contracting under their own gravity. And the tremendous energy released by matter falling toward the star centers might well be of a magnitude that could explain a quasar's fierce radiation.
Hoyle and Fowler are disputed by other scientists who maintain that gravitational collapse of such a very massive star would quickly result in a mind-boggling consequence: the Schwarzschild singularity. In 1916, German Astronomer Karl Schwarzschild used Einstein's equations to demonstrate that very massive bodies can literally gravitate themselves out of the observable universe. When such stars contract to a critical size during catastrophic collapse, Schwarzschild calculated, their gravity becomes so strong that it prevents any matter, or even radiation, from escaping into space. As a result, the stars simply disappear from view; they would be detectable only by their tremendous gravitational force.
Swedish Physicist Hannes Alven has proposed an equally imaginative theory (TIME, Nov. 19). Elementary particles of matter, he says, have been proved in the laboratory to have their counterparts of antimatter. When matter and antimatter meet, they annihilate each other, with the release of tremendous amounts of energy. Though there may be no antimatter in the neighborhood of earth, the Swede argues, it is not unreasonable to assume that half of the stuff in the universe--including whole galaxies--is made of antimatter. The collision of matter and antimatter galaxies might produce the observed quasarlike energies.
Beyond Virgo. Whenever physicists or cosmologists simply cannot square their theories with Schmidt's claim that quasars exist at cosmological distances from earth, they are left with only one alternative: to offer some other explanation for the firmly established quasar red shift. Timeworn arguments that red shift is caused by light that has become "fatigued" or otherwise altered in long journeys through space--not by recessional velocity--were briefly resurrected and then dropped for want of any evidence. But another theory, proposed by Los Alamos Physicist James Terrell and supported by Hoyle and University of California Physicist Geoffrey Burbidge, was not so easily disposed of.
Quasars, they said, may well be "local" objects expelled from the Milky Way or a nearby galaxy by a recent stupendous explosion. While moving away from the earth at velocities approaching the speed of light, they would show a red shift but would be relatively close by. Thus, it would be easier to explain their brightness, and they would not present a threat to the steady-state theory.
There are convincing arguments against the local theory. Maarten Schmidt, for one, cannot believe that the Milky Way or any nearby galaxy could have produced an explosion great enough to impart such huge velocities to local objects. "There is just not enough energy to have shot them all out," he explains. If the explosion were recent enough so that the quasars were still quite close, adds Astronomer Greenstein, some of them would not yet have passed the earth and would be approaching it rapidly. Their light would therefore be moving toward the blue, not the red end of the spectrum. Though a search is on, no blue shifts have yet been detected in quasars.
Perhaps the most convincing evidence against the local theory has been presented by Astronomer J. A. Koehler, working with the 210-ft. radio telescope at Parkes. Koehler found evidence that he was picking up radio emission from quasar 3C 273 that had passed through a hydrogen cloud near the Virgo cluster of galaxies, which are about 40 million light-years from the earth--a strong argument that the quasar is even farther away than the galaxy. Admits Physicist Dennis W. Sciama of Cambridge University: "This result appears to dispose of the possibility that the quasi-stellar sources are close to our galaxy."
Embarrassing Record. In the three years since Schmidt made his discovery, noted astronomers have spent long nights vying for the distinction of finding the quasar with the largest red shift. In December, University of California Astronomer Margaret Burbidge briefly held the record, with an observed red shift for quasar 0106 + 01, indicating that it was racing away from the earth at 81.2% of the speed erf light and was the farthermost object known. In January, however, Schmidt found another quasar (1116+12) with a red shift that is even greater and a correspondingly greater velocity. "I feel a little embarrassed about it," he says. "This thing had to be just 1% above Margaret's." So far, about 90 quasars have been identified and 30 analyzed for red shift, most of them by Schmidt, who believes that about a thousand quasars will eventually be found.
While strict interpretation of Hubble's law would place the farthermost quasars more than 8 billion light-years from the earth, Schmidt refuses to assign a specific distance for any beyond the closest: 3C 273. "We do not know that Hubble's law applies at cosmological distances," he explains. "All we can really say is that if the universe is 10 billion years old, then light from the farthermost quasars has been on the way to us for more than 8 billion years. When the light we see today left the farthermost quasars, the earth and the solar system had not yet been born. And we do not know with certainty what the quasar has done or where it has gone in the past 8 billion years. It may now be a galaxy or just some burned-out remnants."
Superb Work. Such grand, galactic thoughts come easily these days to the man who has been puzzling over the stars ever since he was twelve and his amateur astronomer uncle gave him a look through a telescope. Before he finished high school in the Dutch town of Groningen, where he was born, he had become so expert a student of the skies that his teacher exchanged chairs with him during astronomy lessons and allowed him to address the class. "You know that stuff better than I do," the teacher admitted.
By the time young Maarten had enrolled at the University of Groningen, where he studied mathematics, physics and astronomy, his dedication to astronomy had begun to alarm his father, a government accountant. "How can you earn your daily bread by looking at the stars?", the elder Schmidt asked repeatedly. He was placated only by a direct appeal from University Astronomy Professor Adriaan Blaauw, who saw in the eager young student the makings of an able professional. Upon graduation in 1949, Schmidt was offered a job at the University of Leiden Observatory as an assistant to Astronomer Jan Hendrik Oort, who is famous for determining the rotation of the Milky Way galaxy as well as for his pioneer role in the radio mapping of hydrogen clouds. "His work was superb," says Oort. Perhaps as important to Schmidt as the professor's good opinion was his hospitality. At a staff party at Oort's home, Schmidt met a strikingly attractive blonde kindergarten teacher named Cornelia Tom, whom he married in 1955.
The following year, after earning his doctorate from Leiden, Schmidt won one of the greatest prizes available to a talented young astronomer: a Carnegie Institution fellowship. With it he gained entree into the stimulating atmosphere of Pasadena's California Institute of Technology, and access to the fabulous astronomical complex in Southern California. There, all within easy driving distance of Los Angeles, the world's greatest telescopes point skyward. Atop Mount Palomar is the 200-in. Hale telescope and a 48-in. Schmidt (no relation) wide-angle scope. On Mount Wilson is a 100-in. telescope, one of the world's largest, and a 60-in. instrument that would be the pride of most other observatories. The twin 90-ft. antennas of one of the world's finest radio telescopes stare at the sky from nearby Owens Valley.
Schmidt was warmly accepted in Pasadena. "He was an ideal product of the Dutch school," says Jesse Greenstein. "In this country we tend to stress atomic and nuclear physics in astronomy. Schmidt came to us with more classical training. He had, and still has good sharp eyes at the telescope, an old-fashioned virtue in science."
When his two-year fellowship ended, Schmidt returned home, intent on educating his daughters in Holland. But the lure of Southern California was too great. "Those big telescopes are a little like drugs," he explains. "Once you've worked with them, it's hard not to return." In 1959 he accepted the offer of an assistant professorship at Caltech and came back to Pasadena. The following year, after immersing himself in the specialties of his American colleagues--spectroscopy, cosmic radiation and extragalactic phenomena--he took over the job of retiring Astronomer Rudolph Minkowski, who had been working on spectrograms of radio galaxies. Almost immediately, he found himself "struggling quietly" with the riddle of the curious objects that turned out to be quasars.
Relaxing Habit. Today he devotes part of his time to work on basic theory "trying to figure out what it all means," part to preparation for classwork. He usually teaches radio astronomy or galactic dynamics for three hours a week to Caltech's bright undergraduate and graduate students. This semester, however, normal staff rotation has left him without any classes, enabling him to devote full time to the pursuit of his quasars. Despite the challenges of his job, though, he takes pains never to miss dinner at home. "It is," says Corrie Schmidt, "the only time he really has with the children." At bedtime, Anne, 5, Maryke, 7, and Elizabeth, 9, all stand prim and proper in line, awaiting their ritual kus (Dutch for kiss) from Daddy.
In the evening, Maarten usually mixes work with relaxation. "If I'm doing difficult creative work," he explains, "I keep at it for only a quarter of an hour or so at a time." In between these sessions, he sometimes watches television with Corrie, easing his busy brain with such shows as The Man From U.N.C.L.E. and Get Smart! Another relaxing habit, imported from Holland like the Schmidts, is an occasional belt or two of volatile Dutch Bols gin.
Music provides the Schmidts with still another form of diversion. Maarten plays the violin, Corrie the piano, and both are fond of chamber music. Visiting astronomers and relatives are often pressed into chamber music recitals at the Schmidt home. "If I play," admits Schmidt, "it has to be in an intimate circle. Only my best friends can really stand it."
Even as Schmidt strives to learn about his quasars, scientists are busy investigating other clues from the distant reaches of the universe and looking for new ones. In New Jersey, researchers at the Bell Telephone Laboratories have recorded the dying whisper of what might be radio waves emitted by a cosmological bang 10 billion years ago. In Washington last week, Navy scientists reported that a high-flying Aerobee rocket had detected strong X-ray sources associated with distant galaxies. And NASA officials are preparing for the launching later this month of an orbiting observatory equipped with telescopes for the continuous detection of ultraviolet, gamma and X-ray radiation that cannot be seen through the earth's atmosphere.
All the astronomical excitement, all the ambitious experiments, all the arguments over theory seem more and more a modern version of the confusion that boiled in the wake of Galileo Galilei's telescopic report on the realities of the solar system. The 17th century Italian startled scientists and theologians alike; the 20th century Dutchman has had an equally jarring effect on his own contemporaries as his discoveries have pushed man's scientific horizons out to the farthest reaches of the observable universe.
Just as Galileo set the stage for Sir Isaac Newton, who compiled the laws of planetary motion and gravitation, Schmidt and his colleagues are forcing their contemporaries to exercise their inventive imaginations merely to comprehend what the great observatories have seen, and the clues collected from faint spectrograms may lead science into a new era of understanding. If astronomers can find an explanation for the birth of quasars, they may yet be able to find the secrets of Creation itself; and if physicists become familiar with the mechanics of elemental reac tions far out at the boundaries of perception, they may yet learn the ultimate secrets of matter and energy on earth. For science is fast advancing into areas where the old theories may no longer apply, where the old rules may no longer work. And if Maarten Schmidt's inspired deductions point the way toward totally new equations to account for the nature of the cosmos, Palomar's telescope will have led man to his closest glimpse of universal truths.
* A light-year is the distance that light, at a speed of 186,000 miles per second, travels in a year: about 6 trillion miles. * "3C" stands for the Third Cambridge Catalogue of Radio Sources. The other numbers designated each source's position in the sky.
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