It will be the coldest place on Earth, more deeply frozen even than outer space. About 330ft underground near Lake Geneva in Switzerland this weekend, the temperature should reach -271.25C.
That's just 1.9 degrees above absolute zero, the lowest temperature theoretically possible. But creating this outsize freezer may help unlock the secrets of the universe and our origins.
The Big Chill is under way inside the giant particle accelerator at the European Organisation for Nuclear Research, known as Cern. Last week four tankers made the final deliveries of more than 1,000 tons of liquid nitrogen which, along with helium, is being used in a series of mega-powerful fridges.
Three-quarters of the accelerator, properly known as the Large Hadron Collider (LHC), should be supercooled by today.…