Sep 10, 2008
Science reporter, BBC News
Three decades after it was conceived, the world's most powerful physics experiment has sent the first beam around its 27km-long tunnel.
Engineers cheered as the proton particles completed their first circuit of the underground ring which houses the Large Hadron Collider (LHC).
The £5bn machine on the Swiss-French border is designed to smash particles together with cataclysmic force.
This will re-create conditions in the Universe moments after the Big Bang.
But it has not been plain sailing; the project has been hit by cost overruns, equipment trouble and construction problems. The switch-on itself is two years late.
Read the latest on this story at 'Big Bang' experiment under way.