The Compact Muon Solenoid (CMS) is one of two main detectors at the LHC. It weighs 12,500 tons, measures 69 ft. (21 m) in length and is a key research tool for 2,000 scientists hailing from 37 countries. It was built above ground and lowered into placeââ¬âa sensible strategy for so massive a piece of hardware. Here it is seen in 2008, just before it was completed. (Panorama by Peter McCready)
Thereââ¬â¢s something almost ironic about the disparity of scales between the Large Hadron Collider and the subatomic particles itââ¬â¢s built to study. The collider itself measures 17 mi. (27 km) in circumference, sits 380 ft. (116 m) below ground and cost $10 billion to build. Its detectors and magnets alone weigh tens of thousands of tons. As for the particles that are produced by the proton collisions that take place in the LHC tunnels? They are so tiny and evanescent that they flash into and out of existence in just a few trillionths of a second. But you can learn a lot in that flicker of time.
In order to create the quantum crack-ups that are the whole reason the LHC was built, swarms of protons are sent whizzing around the subterranean racetrack in opposite directions until they attain 99.9999991% of the speed of light. When they collide, they briefly recreate the conditions at the moment of the Big Bangââ¬âin manageable miniatureââ¬âand generate some of the primal particles produced then too. The Higgs boson was one of the most sought-after of those particles, but it had eluded detection for nearly 50 years. When its existence was at last proven in the LHC and announced on July 4, champagne corks popped both within and without the physics world. And with good reason.
