Cern's Large Hadron Collider makes first collisionsBy Paul Rincon
Science reporter, BBC News
Engineers working on the Large Hadron Collider (LHC) have smashed together proton beams for the very first time.
The step was described as a "great achievement" for those working on the giant physics experiment.
The low-energy collisions came as researchers circulated two beams simultaneously in the LHC's 27km-long tunnel earlier on Monday.
The LHC is designed to smash together beams of protons in a bid to shed light on the nature of the Universe.
Researchers working on the collider have said they are delighted with the quick progress made since the machine restarted on Friday.
Operated by the European Organization for Nuclear Research (Cern), the LHC is the world's largest machine and will create similar conditions to those which were present moments after the Big Bang.
"It's a great achievement to have come this far in so short a time," said Cern's 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 programme."
Housed in a tunnel 100m beneath the Franco-Swiss border, the LHC uses some 1,200 "superconducting" magnets to bend proton beams in opposite directions around the tunnel at close to the speed of light.
At allotted points around the "ring", the proton beams cross paths, smashing into one another with enormous energy.
Large "detector" machines located at the crossing points will scour the wreckage of these collisions for discoveries that could roll back the frontiers of knowledge.
Scientists will search for signs of the Higgs boson, a sub-atomic particle that is crucial to our current understanding of physics. Although it is predicted to exist, scientists have not yet detected it.
http://news.bbc.co.uk/2/hi/science/nature/8375486.stm
