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CERN scientists seek to replay the universe’s birth

CERN scientists seek to replay the universe’s birth
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First Published: Tue, May 15 2007. 09 18 AM IST
Updated: Tue, May 15 2007. 09 18 AM IST
90 Metres below Meyrin, Switzerland: The first thing that gets you is the noise.
Physics, after all, is supposed to be a cerebral pursuit. But this cavern almost measureless to the eye, stuffed as it is with an Eiffel Tower’s worth of metal, eight-story wheels of gold boxes, thousands of kilometres of wire and coils, echoes with the shriek of power tools, the whine of pumps and cranes, beeps and clanks from wrenches, hammers, screwdrivers and the occasional falling bolt. It seems no place for the studious.
The physicists, wearing hard hats, kneepads and safety harnesses, are scrambling like Spiderman over this assembly, appropriately named Atlas, ducking under waterfalls of cables and tubes, and crawling into hidden cavities stuffed with electronics.
They are getting ready to see the universe born again.
Again and again and again - 40 million times a second, to be exact.
Starting sometime next summer, if all goes to plan, subatomic particles will begin shooting around a 27-kilometre, or 17-mile, underground ring stretching from the European Centre for Nuclear Research, or CERN, near Geneva, into France and back again.
Crashing together in the bowels of Atlas and similar contraptions spaced around the ring, the particles will produce tiny fireballs of primordial energy, recreating conditions that last prevailed when the universe was less than a trillionth of a second old.
Whatever forms of matter and whatever laws and forces held sway Back Then - relics not seen in this part of space since the universe cooled 14 billion years ago - will spring fleetingly to life, over and over again in all their possible variations, as if the universe were enacting its own version of the movie ”Groundhog Day.” If all goes well, they will leave their footprints in mountains of hardware and computer memory.
”We are now on the endgame,” said Lyn Evans, of CERN, who has been in charge of the Large Hadron Collider, as it is called, since its inception. Call it the Hubble Telescope of Inner Space. Everything about the collider sounds, well, large - from the 14 trillion electron volts of energy with which it will smash together protons, its cast of thousands and the 10 billion Swiss francs it cost to build, to the 128 tons of liquid helium needed to cool the superconducting magnets that keep the particles whizzing around their track, and the three million DVDs’ worth of data it will spew forth every year.
The day it turns on will be a moment of truth for CERN, which has spent 13 years building the collider, and for the world’s physicists, who have staked their credibility and their careers, not to mention all those billions of dollars, on the conviction that they are within touching distance of fundamental discoveries about the universe.
If they fail to see something new, experts agree, it could be a long time, if ever, before giant particle accelerators are built on Earth again, ringing down the curtain on at least one aspect of the age-old quest to understand what the world is made of and how it works.
”If you see nothing,” said a CERN physicist, John Ellis, ”in some sense, then, we theorists have been talking rubbish for the last 35 years.”
Fabiola Gianotti, a CERN physicist and the deputy spokeswoman for the team that built the Atlas, said, ”Something must happen.”
The accelerator, Gianotti explained, would take physics into a realm of energy and time where the reigning theories simply do not apply, corresponding to an era when cosmologists think that the universe was still differentiating itself, like a dividing embryo, evolving from a primordial blandness and endless potential into the forces and particles that constitute modern reality.
She listed possible discoveries like a mysterious particle called the Higgs boson that is thought to endow other particles with mass, new forms of matter that explain the mysterious dark matter waddling the cosmos and even new dimensions of spacetime.
”For me,” Gianotti said, ”it would be a dream if, finally, in a couple of years in a laboratory we are going to produce the particle responsible for 25% of the universe.”
Halfway around the ring stood her rival of sorts, Jim Virdee from Imperial College London, wearing a hard hat at the bottom of another huge cavern. Virdee is the spokesman, which is physics-speak for leader, of another team, about 2,500 strong, with another giant detector, the poetically named Compact Muon Detector, which was looming over his shoulder like a giant cannon.
”The prospect of discovery,” Virdee said, is what sustained him and his colleagues over the 16 years it took to develop their machine. Without such detectors, he said, ”this field which began with Newton just stops.”
”When we started, we did not know how to do this experiment and did not know if it would work,” he said. ”Twenty-five hundred scientists can work together. Our judge is not God or governments, but nature. If we make a mistake, nature will not hesitate to punish us.”
Game of cosmic leapfrog
The advent of the CERN collider also cements a shift in the balance of physics power. That shift, away from American dominance of what has been called the queen of science, the quest to understand what the world is made of and how it works, began in 1993, when the US Congress cancelled the Superconducting Supercollider, a monster machine under construction in Texas. The supercollider, the most powerful ever envisioned, would have sped protons around a 54-mile racetrack before slamming them together with 40 trillion electron volts.
For decades before that, physicists in the US and Europe had leapfrogged one another with bigger, more expensive and, inevitably, fewer of these machines, which get their magic from Einstein’s equation of mass and energy. The more energy that these machines can pack into their little fireballs, the farther back in time they can go, closer and closer to the Big Bang, the smaller and smaller things they can see.
Recalling those times, Evans said: ”There was a nice equilibrium across the Atlantic. People used to come and go.”
Now, Evans said, ”the centre of gravity has moved to CERN.”
The most powerful accelerator now operating is the trillion-electron volt Tevatron, colliding protons and their antimatter opposites, antiprotons, at the Fermi National Accelerator Laboratory in Batavia, Illinois. But it is scheduled to shut down by 2010.
CERN was born amid vineyards and farmland in the countryside outside Geneva in 1954 out of the rubble of postwar Europe. It had a two-fold mission of rebuilding European science, which had been decimated by the exodus of Jewish scientists to the US, and of having European countries work together.
Today, it has 20 countries as members. Yearly contributions are determined according to members’ domestic economies, and a result is an annual budget of about a billion Swiss francs. The vineyards and cows are still there, but so are strip malls and shopping centres.
It was here that the World Wide Web was born in the early 1990s, but the director general of CERN, Robert Aymar, joked that the lab’s greatest fame was as the locus of an international metaphysical conspiracy in the novel ”Angels and Demons,” by the author of ”The Da Vinci Code,” Dan Brown.
In 1994, after the supercollider collapse gave its own collider a clear field, the CERN governing council gave its approval. The United States eventually agreed to chip in $531 million for the project. CERN also arranged to borrow €300 million from the European Investment Bank. Even so, there was a crisis in 2001 when the project was found to be 18 percent over budget, necessitating cutting other programs at the lab. The collider’s name comes from the word hadron, which denotes subatomic particles like protons and neutrons that feel the ”strong” nuclear force that binds atomic nuclei.
Whether the Europeans would have gone ahead if the United States had still been in the game depends on whom you ask. Aymar, who was not there in the ’90s, said there was no guarantee then that the United States would succeed even if it did proceed.
”Certainly in Europe the situation of CERN is such that we appreciate competition,” he said. ”But we assume we are the leader, and we have all intention to remain the leader. And we’ll do everything which is needed to remain the leader.”
To match the American machine, however, the Europeans, with a much smaller tunnel - 17 miles instead of 54 - and a restricted budget, had to adopt a riskier design, in particular by doubling the strength of their magnets.
”In this business, society is prepared to support particle physics at a certain level,” Evans said. ”If you want society to accept this work, which is not cheap, you have to be really innovative.”
Cocktail-party physics
The payoff for this investment, physicists say, could be nothing less than a new understanding of one of the most fundamental of aspects of reality, namely the nature of mass.
This is where the shadowy particle known as the Higgs boson, a k a the God particle, comes in.
In the Standard Model, a suite of equations describing all the forces but gravity, which has held sway as the law of the cosmos for the last 35 years, elementary particles are born in the Big Bang without mass, sort of like Adam and Eve being born without sin.
The Higgs idea is crucial to a theory that electromagnetism and the weak force are separate manifestations of a single so-called electroweak force. It showed how the massless bits of light called photons could be long-lost brothers to the heavy W and Z bosons, which would gain large masses from such cocktail party interactions as the universe cooled.
The confirmation of the theory by the Nobel work at CERN 20 years ago ignited hopes among physicists that they could eventually unite the rest of the forces of nature.
Moreover, Higgs-like fields have been proposed as the source of an enormous burst of expansion, known as inflation, early in the universe, and, possibly, as the secret of the dark energy that now seems to be speeding up the expansion of the universe. So it is important to know whether the theory works and, if not, to find out what does endow the universe with mass.
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First Published: Tue, May 15 2007. 09 18 AM IST
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