The Large Hadron Collider (LHC) uses an array of 9,300 supercooled electromagnets to guide and accelerate particles – namely protons, around the 27km underground ring at CERN in Geneva, up to speeds extremely close to that of light. At their fastest, these particles travel at around 299.8 million metres per second completing 11,245 laps of this ring every second. This is equivalent to travelling around the circumference of the Earth seven and a half times in one second.
The LHC has two rings with beams of trillions of particles zooming around in opposite directions. Detectors are placed at certain points where the pipes intersect causing collisions to occur. As both the particles are travelling in opposite directions at nearly the speed of light, you might expect their combined collision speed to be almost twice the speed of light. However both particles would measure their collision speed to be less than the speed of light. This seems counter-intuitive but is accounted for by the slowing down of time and warping of space as explained by Einstein’s special theory of relativity. This theory explains why no particle with mass should be able to travel faster than light, as it would require an infinite amount of energy to get there!
Answered by – Rik Sargent