The world’s largest particle accelerator has powered down. CERN has switched off the Large Hadron Collider to begin Long Shutdown 3 (LS3), its biggest overhaul yet, swapping 1. 2km of magnets to build the High-Luminosity LHC. The upgraded collider will boost collisions tenfold when it restarts from 2028, fully operational by 2030. No black holes, no doomsday, just a very expensive maintenance window.