Sprung a leak: A large dipole magnet is symbolically lowered into the tunnel in Geneva in April 2007 to mark the end of a crucial phase of installation of the Large Hadron Collider (LHC).
Credit: AFP/CERN
Fundamental questions
The LHC took nearly 20 years to complete and at A$6.6 billion (3.76 billion euros) is one of the costliest and most complex scientific experiments ever attempted.
It aims to resolve some of the greatest questions surrounding fundamental matter, such as how particles acquire mass and how they were forged in the "Big Bang" that created the universe some 13.7 billion years ago.
Counter-rotating beams are whizzed around the tunnel and then are smashed together in four huge laboratories.
Over the 10-15 years in which the LHC will operate, masses of data will spew from these collisions and will be scrutinised by physicists around the world.
The Holy Grail will be finding a theorised component called the Higgs boson, which would explain how particles acquire mass. Also dubbed the "God particle," the Higgs is believed to be ubiquitous yet elusive.
