The LHC operates at nearly absolute zero temperature, colder than outer space, which allows the superconducting magnets to guide the protons most efficiently. Physicists have used smaller, room-temperature colliders for decades to study the atom. They once thought protons and neutrons were the smallest components of the atom's nucleus, but the colliders showed that they are made of quarks and gluons and that there are other forces and particles. And scientists still have other questions about antimatter, dark matter and supersymmetry they want to answer with CERN's new collider. __
