These discoveries enabled physicists to devise a compelling picture of the universe at the subatomic level. Known as the Standard Model, it is considered the most successful scientific theory in history.
It has been able to explain an array of processes through its description of the subatomic world and the dynamics of the four essential forces of the universe: gravity, electromagnetism, the weak force governing radioactive decay, and the strong nuclear force, which binds protons and neutrons together in an atom's nucleus.
But there are problems. First, the Standard Model can't explain why the universe is composed of matter. According to theory, equal amounts of matter and antimatter would have been created in the Big Bang, which created the universe. As soon as they met, they should have annihilated each other, releasing photons of light.
"You should end up with a universe with only light," said Tatsuya Nakada, who directs another of the four major particle detectors at CERN.
The Standard Model also fails to explain why particles have mass.
"In all our equations, the most fundamental particles that we know matter is made of come up massless," said Pauline Gagnon, an Indiana University physicist who works on a detector known as ATLAS. "We know that's a flaw in the Standard Model."
The answers, scientists believe, lie in reactions with the extreme energies that occurred during the first moments after the Big Bang. To reach those energies, they have to push particles as close to the speed of light as possible.
The CERN collider uses a powerful electromagnetic field to accelerate particles. "Think of a swing," said Sandor Feher, a fast-talking Hungarian-born physicist, as he strode through a section of the long collider tunnel. "Each time the beam comes around, the field pushes it a little faster."
At the peak, the hydrogen protons in the new collider will reach 99.9999991% of the speed of light. Each packet of protons will complete 11,245 laps around the collider every second and carry as much power as a speeding train.
The collider will consume as much energy as all the households in Geneva, running up an annual electric bill of $30 million.
To guide the proton beams through the twin tubes of the collider, 9,600 magnets will continually tune the positively charged protons as they speed around the collider. The superconducting magnets are cooled with liquid helium to minus 456.25 degrees, a whisker above absolute zero.
