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. “We aim to have all eight sectors of the LHC at supercooled temperature by about July 15,” said a Cern spokesman.

It is the biggest attempt at supercooling ever seen and is critical to the success of the project, which is designed to investigate the conditions immediately after the Big Bang – the moment of creation – and the fundamental make-up of matter.

When the LHC goes live in August, it will enable scientists to accelerate tiny particles called protons close to the speed of light and study what happens when they smash into each other.

Professor Nigel Glover of Durham University, who will be one of the scientists analysing data from the LHC, said: “We are really going into new territory. We will be able to recreate the conditions immediately after the Big Bang. We hope we will find things we expect . . . and things we don’t expect. It is the most exciting experiment in particle physics in the last 25 years.”

And it wouldn’t work without the fridges.

The LHC will operate by firing particles round tubes running in a circular tunnel nearly 17 miles long. They will be accelerated both ways to such velocity that each proton will circle the tunnel more than 11,000 times a second. Then at certain points – including in the huge Atlas detector – a few particles will collide, explode and, it is hoped, reveal previously unseen aspects of the universe.

The beam of particles will be bent, focused and controlled by 9,300 magnets positioned around the tunnel, with the key ones being 1,232 “dipole” electro-magnets, each weighing about 35 tons. They are made using metals that, at temperatures of -263C and below, become “supercon-ducting”. That means they carry electricity without resistance, making them vastly more powerful than a “warm” magnet.

The first step in making these giant magnets so cold is to use liquid nitrogen to cool them to -193C. That, however, is the easy part. Then the magnets are immersed in baths of liquid helium, and refrigeration turbines reduce the temperature to -268C.

To crack the last few degrees to -271.25C, the LHC has to use a complex pumping system to reduce the pressure of the helium. At -271C helium becomes a “superfluid” flowing with virtually no viscosity, which means it can conduct away heat very efficiently.

All this technology, costing £2.5 billion, will in the end produce collisions with about the same energy as generated when you clap your hands. But it will be concentrated into a space billions of times smaller.

From collisions of such concentrated violence, scientists hope to uncover much more about the building blocks of the universe. At present nobody knows, for example, why elementary particles have mass or why the matter we can see seems to make up only about 4% of the estimated mass of the universe. The LHC may reveal what scientists call “dark matter” and “dark energy” are – if they really exist.

When the LHC becomes fully operational in August, top of the list of objectives is to observe the “Higgs boson”, a hypothetical particle proposed in 1964 by Professor Peter Higgs of the University of Edinburgh to solve the problem of how matter gets mass. If it is found, Higgs, now 79, is likely to win the Nobel prize for physics.

That is, so long as the super-fridges do their stuff.

Times Recommends

• Swine flu vaccine for all as drug rushed through
• Artificial sperm and the race to build a baby
• BBC jets out stars to tout for prizes