Inside the World’s Biggest Particle Collider

A global effort to gain a more complete understanding of the fundamental building blocks of the universe resumed Tuesday near Geneva, as the world’s largest particle collider restarted scientific operations after about a three-year hiatus for maintenance and upgrades.

The Large Hadron Collider, or LHC, operated by the European Organization for Nuclear Research, or CERN, features a 17-mile circular tunnel in which particles like protons are accelerated to nearly the speed of light and then smashed into each other to produce showers of smaller particles. The smashups are analyzed with the help of specialized detectors arrayed around the ring in the hope that the data will reveal previously unknown subatomic particles. That is what happened a decade ago, when CERN scientists announced the discovery of the much-ballyhooed Higgs boson, a particle that gives all matter its mass.