Scientists at Cern in Geneva have restarted the Large Hadron Collider (LHC) experiment, which hopes to shed light on the origins of the universe.
The vast experiment - involving the largest machine in the world - will smash together beams of protons to recreate the conditions in the first moments after the Big Bang.
On Friday evening, several hours earlier than expected, two stable proton beams were sent in opposite directions around the LHC. The Cern scientists said the process had gone smoothly.
The LHC was first put into operation in September 2008 but was shut down nine days later because of an electrical fault.
The scientists said they had learned from the earlier breakdown and understood the machine far better than they had a year ago.
What are these?
One-Minute World News 
E-mail this to a friend 
Bookmark with:
What are these?