We found ourselves on a recent Saturday morning in the amphitheater of the Stanford Linear Accelerator Center, a place on the western edge of the Stanford University campus of rolling hills, well-groomed lawns and gnarled oaks taking the sun. A pool of shimmering pink ice plant marks the guard's station and the entrance to a quadrangle of office buildings in the boxy style of many California State University campuses.
The center is devoted to the care and feeding of the accelerator, whose public side is a concrete structure two miles long, a cross between the Maginot line and a box that a florist might find useful for very-long-stemmed roses. The private side, where the work is done, is buried 20 feet deep to protect the oaks, the amphitheater and the 1,400 people who work there from the radiation generated when the accelerator is working and the 50 million watts of electricity it pulls from Pacific Gas & Electric Co. transmission lines is hurling atoms at speeds approaching that of light.
Our host was Sidney Drell, a physicist a few months into his 60s, with the square jaw of a boxer, thick spectacles and a rugged face that lights up whether he is talking about the precise world of atomic particles, in which he spends part of his time, or the ragged world of humanity, politics and arms control. His intense involvement in both led him to leadership in an international crusade to free his close friend and fellow-physicist, Andrei D. Sakharov, from banishment for talking back to Soviet leaders on matters of conscience. We were part of a group of two dozen friends who know him as a dogged arms-control advocate and who had come to see what he does when wearing his hat as deputy director of the accelerator and not as co-director of Stanford's Center for International Security and Arms Control.
He and his colleagues, he told us, stalk quarks, the mysterious and elemental glue that binds together the bits and pieces of the nucleus of the atom, bundles of energy and anti-energy that in turn hold together all of us and everything around us. In earlier phases of the quark hunt, power was poured into a copper tube the size of a dime that runs the length of the linear accelerator so electrons could ride the power surges like "surfers on a wave," as Drell put it, calling on a gift for simile that is the only window many of us have on the science he practices.
At the end of the two-mile ride through the accelerator's dime-sized tube, the surfers smash against a target and break apart in a concrete pillbox packed with instruments that record the resulting debris so that researchers can scroll through computers later and determine what had been hurled out of the nuclei.
Over time, the power pumped into the copper tube has become so great that Einstein's formula, E = mc 2, has come into play. Energy's conversion into mass meant the electron surfers weighed 100,000 times as much at the end of their two-mile ride as at the start, and instead of smashing atoms they squashed them. "It was like a collision between a Mack truck and a Volkswagen," Drell said, a turn of events not useful to quark hunters. To get beyond that phase, Drell and his colleagues built a small loop at the end of the tube so that the accelerator took on the shape of the dime-store gadgets children use to blow soap bubbles. Electrons now surf down the accelerator's copper tube and flow one way when they get to the loop; positrons ride along with them and flow the other. When they meet at the halfway point, and the inevitable collision occurs, Einstein's principle has turned both into Mack trucks.
The center is now building its third, still larger, loop to move physics closer to its goal of breaking apart the smaller segments of the nucleus instead of simply squashing them. If theoretical physicists are right, debris from future collisions should produce tens of thousands of a fragment, a heavy force, buried in atoms that physicists call the Z-nought, of which a few dozen have splattered into the accelerator's instruments during the quark hunt that began when the accelerator smashed its first atom in the early 1960s. The hope is that the fragments may be the missing link between the properties of gravity and electromagnetism that physicists believe, but have yet to demonstrate empirically, are related.
"That is our Holy Grail," Drell said, "the unifying theory of physics." With thousands of Z-noughts to examine rather than dozens, Drell said, "we would be close to explaining what happened in the Big Bang"--the explosion of energy that physicists believe created the universe of which earth is but a particle and the breathtaking pool of pink ice plant a mere sub-particle. "We won't be able to tell you what happened in the instant before the Big Bang," he said. "That we must leave to the theologians. But we could lay it all out after that instant."