What the Collider Might Discover

The world's largest particle accelerator was successfully fired up today for an experiment many predict will fundamentally alter man's understanding of the cosmos. When it reaches full power later this year, the Large Hadron Collider at the CERN laboratory in Geneva will send beams of protons in opposite directions around a 17-mile underground track at a rate of 11,245 circuits a second — a miniscule fraction less than the speed of light — smash them together and then sift through the debris of explosions that replicate the conditions of the Big Bang. The experiment, which has been beset by delays, has taken 25 years to plan, $6 billion to build and involved over 9000 scientists from around the globe.

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Scientists hope to unlock some of nature's most enduring mysteries: why is the universe expanding at an accelerating rate? What stops our own spiral galaxy, the Milky Way, from unraveling and spilling its contents across the universe? How does gravity work? (See pictures of the Large Hadron Particle Collider.)

A prize discovery will be a particle, the Higgs Boson, which scientists believe gives everything in the universe its mass (some physicists call it the God Particle). Previous detectors at CERN and Fermilab near Chicago have failed to find the elusive Higgs, and a planned supercollider in Texas designed to confirm its existence was never finished after Congress cancelled funding in 1993. Now that the LHC is on the quest, some observers herald Europe as the new center of pure scientific research.

"The LHC is a discovery machine," said CERN Director General Robert Aymar. "Its research program has the potential to change our view of the universe profoundly, continuing a tradition of human curiosity that's as old as mankind itself." (See the top 10 scientific discoveries of 2008.)

The driving principle behind the CERN experiment — and indeed physics itself — is that despite its vast and complex appearance, the universe is actually ordered, rational and elegant. Every major breakthrough in physics has shown the cosmos to conform to mathematical equations so symmetrical and satisfying they can only be described as beautiful. (Physics have christened two of the particles they will study at CERN as "truth" and "beauty," after a Keats poem that suggests the two are interchangeable.)

What drives modern physicists forward is a quest for purer beauty. The Standard Model, the theoretical framework that incorporates all current knowledge about the interaction of subatomic particles, is the closest physicists currently have to a theory of everything. But it is becoming increasingly awkward and messy, and it has holes in it. For example, despite all the gravitational forces that should be reining the universe in and slowing it down, it is expanding at a quickening rate. No one knows why. And something seems to cocoon the universe's spiral galaxies, keeping them from spinning out of control. No one knows what.

For the moment, scientists call these unknowns "dark energy" and "dark matter," respectively. The LHC, by examining the subatomic building blocks of the universe, might explain these mysteries and many others, much as a doctor diagnoses a patient by studying blood work. But according to Tejinder Virdee, a particle physicist from Imperial College London, the best-case scenario will be if the machine uncovers something completely unexpected. "Nature can surprise us... we have to be ready to detect anything it throws at us," he said. "You can make conjectures, but unless you verify the conjectures, they are metaphysics. That's why many of us haven't minded spending our entire working lives building this experiment." Searching for truth and beauty, in other words, is good work if you can get it.

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