[Novo]

Scientists have hailed a successful switch-on for an enormous experiment which will recreate the conditions a few moments after the Big Bang.

They have fired a beam of particles called protons around the 27km-long tunnel which houses the the Large Hadron Collider (LHC).

The £5bn machine on the Swiss-French border is designed to smash particles together with cataclysmic force.

Scientists hope it will shed light on fundamental questions in physics.

The beam completed its first circuit of the underground tunnel at just before 0930 BST.

"There it is," project leader Lyn Evans said when the beam completed its lap. There were cheers in the control room when engineers heard of the successful test.

He added later: "We had a very good start-up."

The LHC is arguably the most complicated and ambitious experiment ever built; the project has been hit by cost overruns, equipment trouble and construction problems. The switch-on itself is two years late.