The LHC is a 27 kilometer (16.8 mile) long particle accelerator — the largest in the world — which has been in development for decades. It was built to get as close as we can to studying the particle interactions that we believe took place at the birth of the universe.
Possibly the most important of the particles scientists intend to study is the long-theorized Higgs boson (popularized as the “God particle”). It is the only Standard Model particle which has not yet been observed, and it is believed to be the particle that imparted mass to the other elementary particles in the first instants after the “big bang”.
What does this mean to us non-particle-physicists? Basically, if the upcoming tests show that the Higgs boson is a real particle, we will have the best and most complete evidence we’ve ever had for the “big bang”. If it is not found, we will know that there is a fundamental problem with our current understanding of particle physics.
The first high-energy collisions are planned for late October, so expect to hear more and bigger news then!