European Organisation for Nuclear Research scientists applaud at the Cern's control centre near Geneva during the switch on operation of the Large Hadron Collider (LHC), the world's biggest atom-smasher in a mission to answer some of the most perplexing questions of the physical universe on Wednesday.

Built in a tunnel 100 metres (325 feet) below ground in a complex straddling the French-Swiss border, the LHC is designed to accelerate sub-atomic particles to nearly the speed of light and then smash them together replicating conditions which prevailed in split-seconds after the "Big Bang" that created the Universe 13.7 billion years ago.

One of the biggest quests will be to find a theorised particle called the Higgs Boson, which could explain nagging anomalies about mass. The Higgs has been dubbed the "God particle," because it is believed to be everywhere but is so elusive.  

Photograph: Fabrice Coffrini/AFP/Getty Images

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