"Big Bang" machine experiences first particle collisions

GENEVA, Nov. 23 (Xinhua) -- The world's most powerful atom smasher on Monday experienced the first collisions of particles, only three days after it was restarted, the European Organization for Nuclear Research (CERN) said.

The world's most powerful atom smasher on Monday experienced the  first collisions of particles, only three days after it was  restarted, the European Organization for Nuclear Research (CERN)  said.

"Today the Large Hadron Collider (LHC) circulated two (particle) beams simultaneously for the first time, allowing the operators to test the synchronization of the beams and giving the experiments their first chance to look for proton-proton collisions," the Geneva-based organization said in a statement.

From early in the afternoon, the two particle beams were made to cross at four points, and the detectors recorded four collisions, it said.

"It's a great achievement to have come this far in so short a time," said CERN Director General Rolf Heuer. "But we need to keep a sense of perspective -- there's still much to do before we can start the LHC physics program."

Housed in a 27-kilometer, circular tunnel at the Swiss-French border near Geneva, the giant machine was designed by scientists to unlock many secrets of the universe by recreating the conditions immediately after the Big Bang which happened some 13.7billion years ago.

That can only be done by colliding two beams of particles circulating in opposite directions at close to the speed of light.

The machine was restarted on Friday, after more than one year of repairs. It was first started on Sept. 10, 2008, but suffered a serious malfunction only nine days later.