The Large Hadron Collider (LHC) is back in business after major upgrades, whipping protons around a 17-mile track at almost the speed of light. The ‘collider’ part of the machine’s name comes from its chief aim–making protons smash into each other. It isn’t easy to make protons collide. Isolated from hydrogen atoms, the protons are remarkably tiny–nearly 3,000 of them inhabit a beam that’s thinner than a hair from your head. Yet the LHC is so powerful that scientists will create 600 million collisions per second with the revamped machine.
The collisions create huge numbers of subatomic particles that swiftly disappear, but not before they are recorded by detectors for analysis. This is how the elusive Higgs boson was detected. The energy upgrade is expected to produce even more revelations, perhaps including a first look at the particles that account for “dark matter”–the substance that theoretically constitutes most of the universe. The LHC work is controversial, too, with a contingent of people who believe scientists are playing God at CERN. These people believe the LHC results could be more like the Bible’s Revelation than scientific revelations like the Higgs boson. Just check out the comments here. But Stephen Hawking says there’s no danger.