Monday, Apr. 16, 1990

The Ultimate Quest

By MICHAEL D. LEMONICK

The elevator doors opened into a cavernous room in an underground tunnel outside Geneva. Out came the eminent British astrophysicist Stephen Hawking, in a wheelchair as always. He was there to behold a wondrous sight. Before him loomed a giant device called a particle detector, a component of an incredible machine whose job is to accelerate tiny fragments of matter to nearly the speed of light, then smash them together with a fury far greater than any natural collision on earth.

Paralyzed by a degenerative nerve disease, Hawking is one of the world's most accomplished physicists, renowned for his breakthroughs in the study of gravitation and cosmology. Yet the man who holds the prestigious Cambridge University professorship once occupied by Sir Isaac Newton was overwhelmed by the sheer size and complexity of the machine before him. Joked Hawking: "This reminds me of one of those James Bond movies, where some mad scientist is plotting to take over the world."

It is easy to understand why even Hawking was awed: he was looking at just a portion of the largest scientific instrument ever built. Known as the large electron-positron collider, this new particle accelerator is the centerpiece of CERN, the European Organization for Nuclear Research and one of Europe's proudest achievements. LEP is a mammoth particle racetrack residing in a ring- shaped tunnel 27 km (16.8 miles) in circumference and an average of 110 meters (360 ft.) underground. The machine contains 330,000 cubic meters (431,640 cu. yds.) of concrete and holds some 60,000 tons of hardware, including nearly 5,000 electromagnets, four particle detectors weighing more than 3,000 tons each, 160 computers and 6,600 km (4,000 miles) of electrical cables. Tangles of brightly colored wires sprout everywhere, linking equipment together in a pattern so complicated, it seems that no one could possibly understand or operate the device. In fact, it takes the combined efforts of literally hundreds of Ph.D.s to run a single experiment.

LEP and other large accelerators have been built to probe the nature of matter on a scale far smaller than that of the atom. The goal is to answer ancient and fundamental questions: What is the universe made of, and what are the forces that bind its parts together? These questions cannot be answered without an understanding of what happened in the Big Bang, the unimaginably hot and dense fireball that 15 billion years ago gave birth to the universe and all it contains.

In a very real sense, accelerators are time machines that re-create the primordial fireball in miniature to unlock its secrets. The collision of two accelerated particles releases enormous bursts of energy. But that energy instantly condenses into a new array of particles, some of which may not have existed since the Big Bang.

This power to go back 15 billion years in time has touched off one of the most heated competitions in the history of science, a race that pits Europe's LEP against U.S. entries led by the powerful Tevatron at Fermi National Accelerator Laboratory (Fermilab) near Chicago and the Stanford Linear Accelerator Center (SLAC) in California. Huge teams of physicists at the rival centers are working day and night to discover the next new particle and to explain the behavior of those already found. In recent years, each lab has had its share of triumphs.

But none of the current generation of accelerators are big enough or powerful enough to re-create the very earliest fractions of a second after the Big Bang, where answers to the most intriguing mysteries are thought to lie. So U.S. physicists have embarked on a bold quest: the building of a colossal collider that will dwarf today's accelerators. Called the superconducting supercollider, it will have a tunnel that will circle for 87 km (54 miles) * under the cotton and cattle country surrounding Waxahachie, Texas. Expected to be completed around the year 2000, the SSC will cost $7 billion to $8 billion.

That enormous price tag has fueled a growing controversy over how much the U.S. can afford to spend on such megaprojects, especially when the knowledge to be gained is so abstract. Critics complain that the money could be better spent on more practical goals, like fighting poverty and improving education. Some scientists, including many researchers in other branches of physics, fear that funding for the SSC will come out of their own budgets. Cynics have argued that the SSC is just another pork-barrel construction project, being foisted on the public by the powerful Texas congressional delegation and backed by a President from Texas.

Yet the support for a giant accelerator goes deeper than a desire for federal dollars. To many scientists and politicians, national pride is at stake. Proponents insist that the SSC is necessary to keep the U.S. in the forefront of particle-physics research. Americans dominated the field from the mid-1940s to the 1970s, but Europe's CERN started stealing much of the glory in the 1980s. Without the SSC, its proponents contend, many of the best American physicists will emigrate to Europe. In fact, the brain drain has already begun: last year, for the first time, the number of American experimenters working at CERN surpassed the total number of scientists from CERN's 14 member countries who had moved to U.S. research centers.

The international competition has spurred remarkable progress in the effort to understand nature's mysteries. Says theoretical physicist Steven Weinberg of the University of Texas at Austin: "Before, we had a zoo of particles, but no one knew why they were the way they were. Now we have a simple picture." That picture, known as the Standard Model, is based on a set of theories that attempt to describe the nature of matter and energy as simply as possible. The model holds that nearly all the matter we know of, from garter snakes to galaxies, is composed of just four particles: two quarks, which make up the protons and neutrons in atomic nuclei; electrons, which surround the nuclei; and neutrinos, which are fast-moving, virtually massless objects that are shot out of nuclear reactions. These particles of matter are, in turn, acted upon by four forces: the strong nuclear force, which binds quarks together in atomic nuclei; the weak nuclear force, which triggers some forms of radioactive decay; electromagnetism, which builds atoms into molecules and molecules into macroscopic matter; and gravity. An entirely separate set of particles -- the bosons -- are the agents that transmit these forces back and forth between particles, people and planets.

The basic "family" of particles is supplemented by two more exotic families, each of which has a parallel structure: two quarks, a type of electron and a type of neutrino. These two extra families are all but extinct in the modern universe, but they apparently existed in the searing heat of the Big Bang, and only accelerators can re-create them. In fact, all of the quarks in all of the families have been found or re-created -- except for the one called the top, which is believed to be the heaviest of all (its mass is at least 90 times that of a proton). Because it would complete the set and thus vindicate decades of theory building, the top quark has become the object of an intensive international search. And because the top is so massive, it will take the energy of the most powerful accelerators to produce it.

But researchers will be awfully disappointed if all they succeed in doing is to fill out the known family tree of particles. Too much predictability can make science dull. Says Samuel Ting, an M.I.T. physicist and one of the head researchers at CERN: "I will only consider our experiment a success if we discover something really surprising -- new types of quarks, for example -- that would explode the standard theory."

Anyone able to take particle physics beyond the Standard Model will automatically win prizes, prestige and added power in the profession. The quest has attracted some of the most driven personalities in science. The leaders, including Ting, CERN director Carlo Rubbia and Stanford's Burton Richter, are known for their relentless ambition, feisty competitiveness and monumental egos. All have already won Nobel Prizes, but that seems only to have increased their desire for greater achievements. In the rush to get results, they push their staffs mercilessly and are furious -- at least in private -- whenever they come in second.

It is this rivalry that speeds the accumulation of knowledge. Observes Jack Steinberger, another Nobel laureate at CERN: "Competition in science is not always a pretty thing, but it's always stimulating and productive." The search for the nature of matter requires brash risk takers because it is a venture into the unknown and perhaps the unknowable. Explains Roy Schwitters, director of the new SSC project: "The physics we do is like a voyage of discovery. You can imagine you're Columbus. We're setting sail to who knows where -- a new world, we hope."

Only a few places are equipped to catch glimpses of that new world. A look at the major explorers:

Fermilab. The machine most likely to find the top quark first is Fermilab's mighty Tevatron, which has been operating for 6 1/2 years beneath the waving grasses of the Illinois prairie. In the Tevatron, strong magnets guide subatomic particles through a circular tunnel that is 6.4 km (4 miles) in circumference. The accelerator is built as a ring so that particles can go around the track again and again, picking up speed with each lap. The ring was built large so that the particles would not have to make sharp turns.

When the machine is running, one beam of particles travels in a clockwise direction while a separate beam goes the opposite way. After reaching maximum speed, the two beams are forced together, and the particles begin to smash head-on into one another, creating fireballs that are 400 million times as hot as the sun -- but so tiny and short-lived that they pose no danger to the accelerator. The Tevatron can produce 50,000 such collisions in a single second. In each of these explosions, the original particles are transformed into a shower of new, short-lived particles. The collisions take place in a detector, which contains a giant magnet that bends the newly created particles in different directions. Scientists cannot see the fresh matter directly, but its characteristics are recorded in computers, and the trails it leaves can be pictured as brightly colored streaks on a video display screen.

Though the Tevatron is considerably smaller than CERN's LEP, the collisions that Fermilab's accelerator produces are much more powerful. Reason: the Tevatron smashes protons into antiprotons, while LEP uses electrons and positrons.* Protons and antiprotons collide with much more force because they pack more energy than electrons and positrons. Think of it as if the Tevatron were crashing Mack trucks together, as opposed to Volkswagens.

The Tevatron collisions produce dense blizzards of particles. Most are uninteresting because they have been observed before, but the chances are relatively good that hidden somewhere in the debris is an exotic new particle. Finding it, though, is no easy task. One reason CERN chose to make LEP an electron-positron machine is because of its comparatively "clean" collisions; though fewer particles are produced, they are easier to locate and study.

Fermilab's physicists believe they have already seen what might be the top quark, but they will have to gather a lot more data to confirm such a discovery. Confidence is already building. Contends James Trefil, a George Mason University physicist: "If the top quark is going to be found, it is going to be found at Fermilab sometime in the next five to six years."

Fermilab is led by director John Peoples, who is widely respected for being a hands-on physicist. But experiments at the lab are not dominated by superstars, such as CERN's Rubbia and Ting. Instead, the atmosphere is one of relative consensus and collegiality. Explains researcher Melvyn Shochet, who commutes to Fermilab from the University of Chicago: "We have pushed to set up a more democratic system, rather than an autocratic system where one person heads up the project." When one team of scientists goes off duty and another comes on, they often share an informal dinner right in the control room. "There's Chinese food with chopsticks, dripping all over the logbooks," says Fermilab physicist Drasko Jovanovic.

It would be a mistake, though, to assume that Fermilab's scientists are any less competitive than their rivals at other labs. The masters of the Tevatron positively gloated last year when they defeated Stanford in a race to measure the mass of the Z 0 particle, a boson that carries the weak force. Says Thomas Devlin, a Rutgers physicist working at Fermilab: "That was fun to beat out our West Coast colleagues. They were hopping mad for a time, but they learned they weren't the only ones to walk on water. It's time they recognized that we also can do good work."

CERN. "Many people doubted that Europe could pull off this venture," said French President Francois Mitterrand in a speech at the gala official opening of CERN's new accelerator last November, "but the achievement of LEP shows that Europe can harness its cultural diversity." In fact, LEP, which took more than four years and nearly $1 billion to build, is much more than a European showcase; it is a laboratory for the entire world. It has attracted scientists from 29 countries in both the West and the East. More than one- third of the Soviet Union's particle physicists are registered to work at $ CERN, as well as a quarter of their colleagues from China.

Most of LEP's 2,000 scientists are split into four teams, each of which operates one of the four particle detectors spread around the accelerator ring. The team leaders are Americans Ting and Steinberger and Italians Ugo Amaldi and Aldo Michelini. The groups compete just as fiercely with one another as they do with outside rivals, creating a setting that is more charged with tension than the comparatively fraternal atmosphere at Fermilab.

The tone and pace for the whole CERN operation is set by Rubbia, a pushy director with a thirst for glory and little patience for laggardly performances. Says one senior CERN researcher: "Rubbia is insensitive, abusive, intolerant and high-handed." Yet no one denies his brilliance, energy and vision. "He works incredibly hard," observes a staffer, "and every waking minute is dedicated to physics." Concedes a critic: "If he was not respected intellectually, he would not be able to get away with the way he behaves. The other mitigating factor is that he is rude to everybody, high and low; he doesn't discriminate." Says Rubbia: "This is my life. There are no half measures."

Rubbia's hard-driving style has paid off. In the early 1980s he was leader of a CERN detector team that discovered the W and Z 0 bosons, crucial linchpins in the Standard Model. That earned Rubbia and colleague Simon van der Meer the Nobel. But Rubbia sometimes goads his scientists into announcing results prematurely. In 1984, for example, he said CERN had found evidence of the top quark, but later had to retract the claim.

By all accounts, the toughest team to belong to at CERN is Ting's. The stern leader would never allow chopsticks and Chinese food in his control room -- or any kind of refreshment, for that matter. He once sent a memo to his staff decreeing that there should be no tardiness, food, drink, joking or shooting the breeze in his lab. "Working for Ting," says one of his senior staffers, "requires the same sort of commitment as taking monastic vows back in medieval times. There is no room here for anybody who is not consumed by the desire to push back the frontiers of physics."

There are no doubt plenty of frontiers left for CERN to push back. Though LEP does not appear to be powerful enough to find the top quark, the "clean" electron-positron collisions could reveal many other exotic phenomena. One long shot is the much-sought Higgs boson, named for British theoretical physicist Peter Higgs, one of the first to recognize its importance. According to some theories, the Higgs boson is what gives all particles their mass. The idea is that everything in the universe is awash in a seaof Higgs bosons, and particles acquire their mass by swimming through this "molasses."

But what the CERN researchers really expect, and hope, to find is something totally unpredicted. "In science nobody really knows what is going to come next," says Rubbia. "We always pretend that we know the answers, but nature keeps advising us that we don't."

To keep finding new answers, Rubbia is determined to improve CERN's technology. He plans to boost LEP's power 50% in the next year or two. CERN is also trying to persuade its member nations to put up the money to build a proton-proton collider in the same tunnel with LEP. Called the large had ron collider, it would be four times as powerful as the Tevatron and almost half as forceful as the proposed superconducting supercollider in Texas. Rubbia thinks he can finish the LHC several years ahead of the SSC and thus beat the Americans to many important discoveries. If the LHC measures up to Rubbia's expectations, SSC could end up standing for superfluous supercollider.

SLAC. Burton Richter, director of the Stanford Linear Accelerator Center, is the maverick of particle physics. While others have recently concentrated on circular accelerators, he has touted the merits of linear models. His latest machine shoots streams of electrons and positrons down a straightaway and then loops them through two semicircular sections onto a collision course. Linear accelerators cannot produce nearly as many collisions as do circular models of comparable power, but Richter claims that the noncircular approach can be an economical way to make discoveries in the vanguard of physics.

Richter has already made his share of breakthroughs. In 1974 he found and named the psi particle, which gave physicists conclusive evidence that quarks really exist. For spotting the psi, Richter shared the Nobel with Ting, who found the same particle at the same time and called it the J. The particle now bears both names, but, says Richter, "when you're talking to Ting, you'd better call it the J/psi. When you're talking to me, call it the psi/J."

Last fall Richter did it again. He was using his new linear collider in a duel with his better-equipped rivals to measure the life-span of the Z 0, the ! particle that carries the weak nuclear force back and forth between other particles. Just one day before CERN was set to announce its measurement, Richter called a press conference to put forward his own figure. The calculation was extremely significant because it provided strong evidence that only three families of matter exist. CERN's Steinberger was furious at being upstaged. "I guarantee our results are more accurate than Stanford's," he told the New York Times. "The people at Stanford knew perfectly well that we were going to do this. They timed their press conference to get in ahead of us, even though we have ten times as much useful data. They've done some nice work, but I don't like it when they try to beat us by one day."

Richter believes that LEP is the end of the line for circular electron- positron colliders. He once calculated that a LEP-style machine with ten times LEP's power would have to be at least 2,700 km (1,680 miles) around. Thus Richter is convinced that linear colliders are the machines of the future. He is hoping to build a 7-to-8-km (4.4-to-5-mile) linear model that he figures could be five times as powerful as LEP. The only catch: it would require acceleration technology that has not yet been invented.

Superconducting Supercollider. For all Rubbia's and Richter's plans, the SSC will clearly have the best chance of unlocking the deep secrets of the universe. Its scale and complexity will make even LEP look puny. The 10,000 magnets will require as much steel as a battleship and enough superconducting wire to circle the earth's equator 25 times. The counterrotating beams of protons, each as thin as a fork's tine and containing quadrillions of particles, will whip around the ring-shaped tunnel 3,000 times, producing up to 100 million collisions, every second.

Building such a mammoth machine from scratch is scary even to Schwitters, a Harvard physicist and leading particle experimentalist who left Fermilab to take charge of the SSC. Says he: "We have to build the equivalent of the Fermilab complex and then the SSC itself." Moreover, since no one has ever built an accelerator of such size and power, each component will have to be reliably mass-produced, which will inevitably cause unanticipated problems. Schwitters is determined to use the best possible designs, even if Congress grimaces at the $7 billion-plus price tag. Former Fermilab director Leon Lederman, one of the early champions of the SSC, thinks it would be idiotic to cut corners on such a complex machine. Says he: "The worst thing in the world would be to build a machine that doesn't work, or one where you have to struggle along."

Another challenge facing Schwitters, who alternates between private fights with Government bureaucrats and public appearances in cowboy boots and a ten- gallon hat, is to recruit hundreds of physicists to work on the accelerator. That may not be so easy. Once it is built, the SSC will be a magnet for young, ambitious scientists. But since Congress will have to appropriate hundreds of millions of dollars each year for the next half-decade for the project, there is always a chance that the money will suddenly dry up, along with jobs. CERN's budget, on the other hand, is shouldered by 14 European governments, thereby spreading the risks and costs.

But for the top physicists, who will have no trouble finding jobs even if the SSC construction were to stop suddenly, the lure of the giant collider is irresistible. In fact, the leaders of the 500-scientist teams that will eventually run the SSC's enormous detector experiments are already beginning to organize. One such collaboration is being formed by Ting. Politically shrewd, he has wooed physicists from a number of weapons laboratories and Southeastern universities, which until now have not been powers in the field of particle physics. Observers expect he will run the experiment in the strictly hierarchical fashion he has displayed at CERN. At the same time, physicists from Lawrence Berkeley Laboratory, Fermilab, Argonne National Laboratory and Japan are drawing up a collaboration that will be run along the more democratic lines of Fermilab. The clash of cultures between the CERN and Fermilab styles of management may make the sociology of the SSC nearly as interesting as the science.

The science should be nothing short of spectacular. By the SSC's projected start-up date of 2000, most of the i's and t's of the Standard Model should long since have been dotted and crossed. Finding the Higgs boson should complete the task. But, contends Columbia University's Frank Scuilli, "there are intrinsic limits to the model, and people believe those limits are going to show up in the SSC, along with a whole new layer of matter we didn't know of before."

The layer that theorists most eagerly hope for is a new class of matter called supersymmetric particles, whose existence is predicated on the so- called grand unified theories now being explored by physicists. Some think that supersymmetric particles are the long-sought components of "dark matter," the invisible stuff that is believed to make up 90% or more of the universe.

Supersymmetric particles could also give a boost to superstring theory, one of the hottest ideas in theoretical physics. Superstring theory holds that every particle is really a vibrating loop of stringlike material that exists in ten-dimensional space (most of these dimensions are confined to such a small scale that we never notice them). Whether the string takes on the role of a quark or an electron or a Higgs boson depends simply on how it vibrates.

Or the theorists may be on the wrong trail entirely. While such ideas as supersymmetry and superstrings may be elegant physics, the supercollider could just as easily reveal a subatomic monkey wrench. That could force a crisis in physics, followed by a far more basic set of theories than physicists now dream of. It may be, for example, that quarks are not fundamental after all, but are themselves made of still more basic building blocks. Some forward thinkers have already coined a name for the ingredients of quarks: preons.

But is finding such exotic particles worth the multibillion-dollar price tag of the SSC? Is it a good investment? No one can know what the payback will be, but past breakthroughs in physics have tended to create whole new industries. Radar, X rays, television, microwaves, semiconductors, computers, lasers -- technologies that now produce as much as a quarter of the U.S. gross national product -- stemmed from discoveries in quantum physics made between 1910 and 1930. "If all of the physics generated by the SSC and its cousins doesn't have a profound effect," says Lederman, "it will be the first time in history."

There is no reason for the U.S. to shoulder the full cost of the SSC. When the supercollider was first proposed, it was assumed that other countries would help support the project both scientifically and financially, much as CERN's LEP is backed by its participating nations. Several foreign governments have offered to do just that. The Japanese have made involvement in the SSC a high priority, and even India has offered to donate $50 million worth of goods and services. Unfortunately, nothing has come of these overtures. Part of the problem, insiders say, is lack of follow-through by the staff at the Department of Energy, which is overseeing the venture. But the SSC remains ( all-American largely because a few key Congressmen still believe that sharing knowledge about subatomic particles is somehow akin to sharing the secrets of the atom bomb.

Whether or not the U.S. pays the entire cost of the of the project, there are no guarantees that the SSC will yield practical results anytime soon or that the physicists will not be back ten years from now asking for an even costlier machine. In the end, the only real justification for building the supercollider is for its value to science, for what it may add to the storehouse of human knowledge. It is difficult to put a price on such a commodity. How much is it worth to know what matter is made of, or what happened in the very first moments after the Big Bang? The answer will vary from individual to individual. Some people think the space program was a big waste of money. Others believe it was worth the cost just for one picture of the earth floating like a fragile island of life in the black void of space.

Particle accelerators have come a long way since the 1930s, when they were literally no larger than a bread box. Since then, each bigger and better machine has pushed physics to a new energy level and has uncovered important and fascinating new facets of matter. If the SSC is built, it should do the same -- taking yet another step in a mind-stretching adventure whose end is not yet in sight.

FOOTNOTE: *Antiprotons and positrons are examples of antimatter, a rare set of particles that mirror normal matter. A proton is positively charged, but an antiproton is negative. The counterpart of the negative electron is the positive positron.

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