Large Hadron Collider

The Big Bang
LHC Computing Grid Globe
(Credit: CERN)

The Large Hadron Collider (LHC) is the most powerful particle accelerator ever built. Based at the European particle physics laboratory CERN, near Geneva in Switzerland, it is the world’s largest laboratory and is dedicated to the pursuit of fundamental science.

The LHC allows scientists to reproduce the conditions that existed within a billionth of a second after the Big Bang. This is the moment, around 14 billion years ago, when the Universe is believed to have started with an explosion of energy and matter. During this first moment of time the particles and forces that shaped our Universe came into existence.

Scientists recreate these conditions by colliding beams of high-energy protons or ions at close to the speed of light. This takes place inside the LHC’s 27km circular accelerator 100m below the ground.

On 4 July 2012 two of the experiments on the LHC, ATLAS and CMS, announced that they had detected a Higgs-like Boson. Further announcements since have confirmed that it is the boson physicists have been looking for since it was predicted 50 years ago. This is one of the greatest discoveries of our time made possible by the unique conditions of the LHC.

Key facts

The LHC is exactly what its name suggests - a large collider of hadrons. Strictly, LHC refers to the collider; a machine that deserves to be labelled ‘large’, it not only weighs more than 38,000 tonnes, but runs for 27km (16.5m) in a circular tunnel 100 metres beneath the Swiss/French border at Geneva.

However, the collider is only one of three essential parts of the LHC project. The other two are:

  • the detectors, which sit in 4 huge chambers at points around the LHC tunnel
  • the GRID, which is a global network of computers and software essential to processing the data recorded by LHC’s detectors

The LHC’s 27km loop in a sense encircles the globe, because the LHC project is supported by an enormous international community of scientists and engineers. Working in multinational teams, at CERN and around the world, they are building and testing LHC equipment and software, participating in experiments and analysing data. The UK has a major role in leading the project and has scientists and engineers working on all the main experiments.

Big Questions addressed by the LHC

Candidate Higgs to two-photon event in CMS
(Credit: CERN)

The Universe started with a Big Bang – but we don’t fully understand how or why it developed the way it did.

The LHC lets us see how matter behaved a tiny fraction of a second after the Big Bang. Researchers have some ideas of what to expect – but also expect the unexpected!


Big Questions about the LHC

The Big Bang
(Credit: CERN)

People sometimes refer to the LHC recreating the Big Bang, but this is misleading. What they actually mean is:

  • recreating the conditions and energies that existed shortly after the start of the Big Bang, not the moment at which the Big Bang started
  • recreating conditions on a micro scale, not on the same scale as the original Big Bang
  • recreating energies that are continually being produced naturally (by high energy cosmic rays hitting the earth’s atmosphere) but at will and inside sophisticated detectors that track what is happening

No Big Bang – so no possibility of creating a new Universe.


Charlotte Jamieson
UK CERN Liaison and Accelerator Programme Manager
Tel: +44 (0)1793 442 027
CERN website:

For media enquiries please telephone: +44 (0)1235 445 627

See also



7 images of Large Hadron Collider
The Big Bang
The Big Bang
Credit: CERN
520 646_th_4.jpg 646_web_4.jpg /646/646_web_4.jpg The Big Bang
LHC Computing Grid Globe
LHC Computing Grid Globe
Credit: CERN
521 646_th_5.jpg 646_web_5.jpg /646/646_web_5.jpg LHC Computing Grid Globe
Candidate Higgs to two-photon event in CMS render
Candidate Higgs to two-photon event in CMS rendered using SketchUp
Credit: CERN
650 646_th_6.jpg 646_web_6.png /646/646_web_6.png Candidate Higgs to two-photon event in CMS render
LHC dipole
3D cut of the LHC dipole
Credit: 2014 CERN
1026 646_th_7.jpg 646_web_7.jpg /646/646_web_7.jpg LHC dipole

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