At 27 kilometers long, it is the largest machine in the world. It will accelerate counter rotating beams of protons to within a whisker of the speed of light and smash them head-on 600 million times a second. The most distinctive feature of the Large Hadron Collider, though, is its temperature. At 1.9 kelvin – a smidgen above absolute zero – the LHC is the coldest ring in the universe, unless an alien civilization has built one that is colder.
Were it not for this searing cold, the LHC might have suffered the same fate as the Superconducting Super Collider (SSC), which was on its way to becoming the most powerful accelerator in the world before the US government canned it in 1993. The SSC’s partially completed tunnel, near Waxahachie, Texas, now lies derelict – killed by a ballooning budget
via newscientist tec