Gravity causes the 27km ring of the Large Hadron Collider near Geneva to shrink and expand by 1mm twice a day
In 1992, physicists working on the Large Electron-Positron (LEP) Collider near Geneva, whose subterranean tunnel loop now contains the Large Hadron Collider, noticed something odd. Twice a day they had to boost the energy of their circulating electrons and positrons (‘antimatter’ partners of electrons) to keep them in the ring. After scratching their heads, they realised that tides happen twice a day. What was happening was that the gravity of the Moon was causing the rock of the Jura Mountains, into which LEP was bored, to bulge upwards. This increased its length so that the magnets were no longer the right strength to trap the beam within the tunnel. Surely one of the most esoteric effect of the tides there is!
The LEP Collider, as seen from the air in the late 1980s. It’s since been dismantled but the circular tunnel remains; it now houses the Large Hadron Collider