Thursday, January 6, 2011
World's Largest 'Atom Smasher' Goes Online
During the wee hours Eastern U.S. time today, an international team of scientists in Switzerland flipped a switch to bring online a gargantuan machine that could change forever what we know about the universe. While the control center erupted with applause and hundreds of thousands watched a live Internet broadcast of the event, skeptics ducked for cover over worry the world would go out with a Big Bang the same way it came in.
That didn't happen.
"It's a fantastic moment," said Lyn Evans, director of the Large Hadron Collider, as the instrument is known. "We can now look forward to a new era of understanding about the origins and evolution of the universe."
The approximately $9 billion LHC is the world's largest particle accelerator and likely the most daunting machine humans have ever built. Although often referred to as an atom-smasher, the collider won't actually smash atoms but rather protons—relatively large bits that make up the nucleus of an atom. By shattering protons into shards of barely-matter so infinitesimally small and nearly devoid of mass, scientists hope to generate the postulated Higgs boson, the missing link that spawned something from nothing—matter from galactic goo—in the earliest instants of the Big Bang. Indeed, the cosmic progenitor of Everything.
An estimated 10,000 people from 60 countries have helped design and build the accelerator and its massive particle detectors, including more than 1,700 scientists, engineers, students and technicians from 94 U.S. government-supported university and national laboratories.
On the count of trois, 9:30 am local time at the European Organization for Nuclear Research (CERN) in Geneva, officials set in motion one of two proton beams whizzing around the icy 17-mile ring. Later they sent a beam in the opposite direction.
Scientists have been cooling all eight sectors of the instrument to a superfrigid -271 degrees C (-520 degrees F) over the summer and powering up its 9,500 magnets, which are so powerful they bend beams of almost nothing traveling at nearly light-speed to keep them within the circle. Some of the magnets focus the beams to improve the chances proton meets proton in a cataclysmic crash that produces the mysterious boson.
"It's like sending needles from either side of the Atlantic and getting them to collide halfway," said David Barney, a physicist affiliated with one of the detectors.
But if no one has ever seen a Higgs boson, how will scientists know when they find one?
Researchers admit the odds of such tiny particles colliding are very low—maybe 20 collisions for every 200 billion particles. Still, the beams will be so particle laden and run at such high speeds, the instrument at full bore can generate up to 600 million collisions every second.
Six massive particle detectors stationed around the ring will look for different collision products and measure their positions, their charges, speed, mass and energy and how the particles decay. Two detectors—A Toroidal LHC Apparatus (ATLAS) and the Compact Muon Solenoid (CMS)—will look specifically for bosons but also explore extra dimensions and the vast, dark matter and energy that make up most of the universe but remains hidden from modern instrumentation.
A total of 41 international funding agencies participate in the ATLAS detector project and 37 participate in the CMS detector project. The U.S. Department of Energy and the National Science Foundation have contributed $531 million to support construction of the two detectors.
LHC scientists say the crashes will produce a boson maybe once every few hours per experiment. At that rate, it could take 2 to 3 years to gather enough data to formulate a reliable picture of the particle. It's no surprise then, the instrument is supported by a huge high-performance computing grid capable of crunching massive amounts of data—some 15 petabytes (15 million gigabytes) annually. Computing centers, including the Open Science Grid in the United States, are located around the globe for scientists worldwide to access the data for analysis.
Over the next few weeks, LHC operators will bring both proton beams into play at the same time and ramp up the machine's acceleration systems to begin real-time experiments.