Heat (38 page)

Building 1005 stands above the tunnel. I meet the physicist in front of Building 1005. I worry that I am wasting her time, a tourist of heat interfering with high-energy physics, but she smiles. She, too, enjoys visiting the collider. Although she has worked on it since its beginning, even during its design, there are parts of it that she has not seen. This is the nature of big science. It involves brigades of scientists and engineers, all working together, some never meeting in person but melding the output of their brains to create a collective capable of something like this, capable of seven trillion degrees. She is as interested as I am.

And when her experiments are running, she cannot visit the tunnel. No one can. When the experiments are running, when gold nuclei race around the circuit, occasionally slamming into one another and disintegrating into their elemental early universe stuff, the tunnel is completely off-limits.

Before we go to the tunnel, to the hottest of all places, we tour the refrigeration plant. To make the hottest of all temperatures requires something approaching the coldest of all temperatures. The particles that these geniuses collide have to be accelerated, and that acceleration uses powerful magnets—1,240 of them—and those magnets require the superconductivity that comes with temperatures approaching absolute zero, temperatures approaching 460 degrees below zero Fahrenheit.

We look over the banks of compressors and heat exchangers. Today they sit idle, quiet. During experiments, in operation, they create a deafening din. In principle, it is the same din that comes from a home refrigerator, but scaled up. And instead of Freon or some similar refrigerant, it uses liquid helium, and instead of striving for temperatures at which one can safely store ice cream and salmon, it strives for the very cold temperatures needed to promote superconductivity.

The walk from the refrigeration plant to the tunnel requires no more than five minutes. We go down steps and around a corner into the tunnel itself. Radiation that escapes from the particle beams will travel in a straight line, hitting a concrete wall, leaving anyone around the corner secure.

There are measures to ensure that no one is inside during experiments. There is a badge system, a security camera monitors the coming and going of workers, and access depends on an elaborate key system. No one starts this car unless everyone is outside the tunnel.

The inside of the tunnel itself resembles an underutilized utilidor, big enough for a single lane of traffic, but it holds nothing more than two pipes and a few wires and a rack hanging down from the ceiling, above the pipes. The entire tunnel is scrupulously clean. One could, without hesitation, eat from its floors. The tunnel’s walls curve like the gentle curve of a railroad track. The pipes, at this location, run side by side as far as I can see along the curving route. But elsewhere, beyond my line of sight, they cross.

The pipes, on stands that hold them waist high, are eighteen inches in diameter. A blue racing stripe marks the pipe on the inside track, indicating that its particles will travel clockwise. A yellow racing stripe marks the pipe on the outside track, indicating that its particles will travel counterclockwise.

Each pipe, for the most part, holds insulation. Inside that insulation, smaller pipes hold the liquid helium that cools the magnets. Those magnets surround another pipe, an innermost pipe. This innermost pipe, a few inches in diameter, runs through the center of the outer pipe.

Inside the innermost pipe, for the most part, there is nothing. It holds a vacuum. But in the center of that vacuum, in the center of the innermost pipe, itself in the center of the outer pipe, a beam with a diameter of four one-thousandths of an inch occasionally flows. That beam is occasionally full of flying particles. The particles are gold.

The physicists convert elemental gold into gold ions, gold molecules stripped of their electrons. Those gold ions are sent into that tiny beam in tiny batches. Inside the beams that are inside these pipes—the beam in one pipe going clockwise, the beam in the other pipe going counterclockwise—batches of gold ions are pushed toward the speed of light.

Where those pipes cross, where batches of ions meet in the most dangerous of intersections, gold ions are annihilated. This is not merely a matter of fission. The ions are not merely turned into smaller atoms. They are not merely turned into scattered protons and neutrons. Parts of them are annihilated, some of their protons and neutrons converted to quarks, the particles that make up protons and neutrons. Protons and neutrons are destroyed.

In the lifetime of this supercollider, the physicists will go to great lengths to destroy a few grams of gold. Collectively, the gold they destroy would not be enough for a wedding band. But somewhere out of sight, down this tunnel, around the curve, where the gold becomes quarks, physicists have observed temperatures of seven trillion degrees.

We drive to the PHENIX detector. It sits in a room the size of a gymnasium, but it is a gymnasium with two stories of hardware, all with one purpose: to intercept the debris cast out by gold ions colliding at close to the speed of light, to collect data, to understand.

The hardware looks something like the armature of a giant electric motor. Or like a hospital’s CAT scanner. Or like a metal press of the kind used to crush scrap metal. Or like all of these and none of them. The PHENIX detector is in fact unique, custom built from the ground up at a cost of something like a hundred million dollars, with its metal surfaces painted green and yellow and blue or buffed to an unpainted shine, with cables of black and red.

Now, between experiments, the detector is open, its guts exposed for maintenance. In the middle of it, surrounded by machinery, a single pipe stands out, a tube a few inches in diameter, well above my head. When the experiment runs, monumental collisions occur inside the tiny beam inside that pipe. They have occurred not once or twice but millions of times, at rates of tens of thousands per second. Most are glancing blows, ionic fender benders. But some are head-on, full speed, front bumper into front bumper, headlights into headlights, no braking, no swerving, a game of chicken played right through to its shattering climax.

I stare at the point of collision, at the tube that, when the experiments are running, holds the action. I am distracted by it. Its presence converts me into a rubbernecker. But it is more than that. I am more like a novitiate drawn to the altar. For a moment, I cannot take my eyes away from the tube. In looking, I trip over a rail on the floor and almost fall. I embarrass myself by staring at the tube, drawn in by what has happened here. In this tube, a phase transition occurred, similar to the phase transition from ice to water, from water to steam, but here it was from matter made of protons and neutrons to something else, something different from normal matter. It was a phase transition that left behind a quark soup at seven trillion degrees.

Yet there is nothing to see, nothing but a shining pipe sitting idle and surrounded by machinery. Each collision lasted no longer than a fraction of a fraction of a fraction of a second, and although gold nuclei are large compared to the nuclei of more common elements, they are small. The heat dissipates long before it reaches the walls of the tube, like the heat from a burning race car dissipating before it reaches fans in the upper bleachers. The tube that has contained seven trillion degrees stands intact, inanimate, unassuming and inexpressive of what went on within its walls.

The particles of interest to the physicist, the debris from head-on collisions, fly through the walls of the pipe. The debris moves through the spaces between the molecules of metal just as light moves through glass. Some of them—enough of them—are intercepted by detectors. Those detectors send their signals to computers. Those computers generate beautiful starburst diagrams that show the track lines of debris. And from those track lines, physicists know, among other things, the temperature at the point of collision. It is as though they have an infrared thermometer capable of reading a temperature from the tiniest of points, for the tiniest fraction of a second.

The strange thing, the physicist tells me, the really weird thing, is what they found at seven trillion degrees. They found something unexpected, something that the theorists had not predicted. They found that materials at this temperature behave as almost perfect liquids, as strongly coupled plasmas. They found a quark soup that flowed without resistance, with almost no viscosity.

Liquids like this have been found before, but never at extremely high temperatures. Liquids like this, nearly perfect liquids, liquids with almost no viscosity, are known to form at temperatures approaching absolute zero.

The physicist and her colleagues must have felt much the same as the physicist Isidor Rabi did in the 1930s. Confronted with the unexpected discovery of subatomic particles called muons—particles that were not predicted by then current theory, particles that did not fit with then current theory—Rabi made a remark remembered by every particle physicist. His remark: “Who ordered that?”

Today string theorists work to understand what the behavior of quark soup means. They work with equations that make no sense, forcing the math to explain what remains, for now, unexplainable.

“What comes next?” I ask the physicist. And she understands my meaning. She knows that I am asking if there will be higher temperatures, and what these higher temperatures might do. She says that the collider in Switzerland, the Large Hadron Collider, has a circumference eight times greater than that of the Brookhaven collider. It smashes lead ions into one another with fourteen times the power of the Brookhaven collider. Nothing has been published yet, nothing is for sure, but she believes the physicists at the Large Hadron Collider may already have achieved temperatures 30 percent higher than hers.

“Quarks are thought to be the fundamental building blocks of the universe,” she tells me. But her voice carries a thread of doubt. It may be that quarks are the end of the road, that no amount of heat will reduce quarks to something smaller, to something even more elusive. On the other hand, every time that physicists have found the smallest building blocks, something smaller has come up. There were molecules, and then atoms, and then protons and neutrons, and then quarks. And now what? 

Two centuries ago, Antoine Lavoisier thought of heat as a subtle fluid. A century ago, the theoretical groundwork behind the atomic bomb was framed. A half century ago, the first nuclear bomb was exploded, and seven years later the first hydrogen bomb. Now controlled collisions annihilate protons and neutrons and generate seven trillion degrees of heat in the name of peacetime research. And a hundred years from now?

Tyndall, in his biography of Faraday, felt compelled to justify science. He talked of electric wires crisscrossing London streets. “It is Faraday’s currents,” he wrote, “that speed from place to place through these wires.” But in contrast, this: “What has been the practical use of the labours of Faraday? But I would again emphatically say that his work needs no such justification and that if he had allowed his vision to be disturbed by considerations regarding the practical use of his discoveries, those discoveries would never have been made by him.”

As for myself, I play with candles and walk through fires and read the words of long dead writers, I burn pilfered peat, I stare at Bronze Age corpses, I drink oil, and I am forever enthralled by Brookhaven’s pipes. At the top of the thermometer, beyond any temperature that I could possibly imagine, those pipes explore conditions near the beginning of the universe. And across the water, in Switzerland, a larger collider sends lead nuclei hurtling toward one another—lead instead of gold, so heavier particles, traveling just as fast or faster, smashing into one another in ways that will create still hotter temperatures, reaching back in time just an instant closer to the birth of the universe, to a time that remains entirely mysterious and speculative. In my day-to-day life, bundled in a thick coat or standing before my woodstove or moving along a snow-covered trail, I find myself thinking of those pipes. And when I think of them, I remember that at the top of the thermometer lies matter with the audacity to behave as though it were absolutely cold, flowing like a perfect liquid, and without a doubt doing so in a manner that will change the way in which people understand the history of the early universe, that time before the first second passed, before protons and neutrons, before hydrogen and stars, before our earth warmed and cooled and warmed again.