Large Hadron Collider

About the LHC

The LHC is an international research project based at CERN in Geneva, Switzerland, where scientists, engineers and support staff from 111 nations are combining state-of-the-art science and engineering in one of the largest scientific experiments ever conducted.

The LHC is the latest and most powerful in a series of particle accelerators that, over the last 70 years, have allowed us to penetrate deeper and deeper into the heart of matter and further and further back in time. The next steps in the journey will bring new knowledge about the beginning of our Universe and how it works, as the LHC recreates, on a microscale, conditions that existed billionths of a second after the birth of our Universe.

What is the LHC?

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 and
   * 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.

What will the LHC do?

The LHC will allow scientists to probe deeper into the heart of matter and further back in time than has been possible using previous colliders.

Researchers think that the Universe originated in the Big Bang (an unimaginably violent explosion) and since then the Universe has been cooling down and becoming less energetic. Very early in the cooling process the matter and forces that make up our world ‘condensed’ out of this ball of energy.

The LHC will produce tiny patches of very high energy by colliding together atomic particles that are travelling at very high speed. The more energy produced in the collisions the further back we can look towards the very high energies that existed early in the evolution of the Universe. Collisions in the LHC will have up to 7x the energy of those produced in previous machines; recreating energies and conditions that existed billionths of a second after the start of the Big Bang.

The results from the LHC are not completely predictable as the experiments are testing ideas that are at the frontiers of our knowledge and understanding. Researchers expect to confirm predictions made on the basis of what we know from previous experiments and theories. However, part of the excitement of the LHC project is that it may uncover new facts about matter and the origins of the Universe.

One of the most interesting theories the LHC will test was put forward by the UK physicist Professor Peter Higgs and others. The different types of fundamental particle that make up matter have very different masses, while the particles that make up light (photons) have no mass at all. Peter’s theory is one explanation of why this is so and the LHC will allow us to test the theory. More of the Big Questions about the universe that the LHC may help us answer can be found here.

How does the LHC work?

The LHC accelerates two beams of atomic particles in opposite directions around the 27km collider. When the particle beams reach their maximum speed the LHC allows them to ‘collide’ at 4 points on their circular journey.

Thousands of new particles are produced when particles collide and detectors, placed around the collision points, allow scientists to identify these new particles by tracking their behaviour.

The detectors are able to follow the millions of collisions and new particles produced every second and identify the distinctive behaviour of interesting new particles from among the many thousands that are of little interest.

As the energy produced in the collisions increases researchers are able to peer deeper into the fundamental structure of the Universe and further back in its history. In these extreme conditions unknown atomic particles may appear.

Who benefits?

There are two types of benefit that the LHC project produces for the UK. The less easily measured benefits are:

   * new understanding of the physical world,
   * training of world class scientists and engineers,
   * maintenance of a vibrant, world class UK research base and,
   * a leading role in a major international project.

More easily appreciated are the knowledge, expertise and technology that is spun off from the LHC and can be directly applied to development of new medical, industrial and consumer technologies (more...[1])

The science of the LHC is far removed from everyday life, but the fact that the science is so extreme constantly pushes the boundaries of existing technical and engineering solutions. Simply building the LHC has generated new technology.

The LHC is not primarily about building a better world. Rather, it allows us to test theories and ideas about how the Universe works, its origins and evolution. The questions asked, and answers found, are so fundamental that the information from LHC experiments will only be applied many years in the future, if at all. However, this is an experiment and one of the surprises from the experiment may be new science that can be applied almost immediately.

For Students Exploring the outer limits of knowledge

The LHC is the most exciting science adventure of this decade; a huge international project exploring the boundaries of our knowledge and theories about the world we live in. The LHC experiments will help us understand the origins and evolution of our universe and possibly reshape how we think about the physical world. Screen shot of particle detectives home page

See a young physicist describing how the study of particle physics has affected our lives and our understanding of the universe we live in and hear how the LHC may be our window into a weird world of missing matter and quantum physics.

[2] the fundamental building blocks of nature, [3] the fundamental forces of nature, [4] the quantum world and the hunt for the Higgs boson.

Drive our simulator at and learn how LHC scientists will conduct their experiments. This website includes a collection of resources for 14-16 and 16+ year old students on 'how science works' and particle physics. Your own discoveries or listen to the video clips of students questionning scientists about the LHC project and download Powerpoint presentations on LHC science.

There are simulations and pages of information on particle physics at the Lancaster Particle Physics pages. These are suitable for AS/A2 16+ students. There is a section dedicated to the LHC.

A simple game that illustrates how scientists search for new particles can be found on the Science Museum's website.

UK scientists have major roles in this project, which involves thousands of scientists and engineers from around the world working in harmony, to build and run the biggest experiment in the history of science. The project will continue for at least 15 years, so anyone considering science as a GCSE option now could be working on the LHC ... and contributing to new discoveries … in the future.

The science of the LHC is directly relevant to areas of the A-level (and equivalent) curriculum, but the project is also an example of how science works and there are many role models and career stories among the diverse community of scientists, engineers and administration staff working on the LHC.

A lot of resources on the LHC and particle physics are available and more will be produced over the life of the project. Visit the resources pages on the STFC website to download, or order, a stunning A1 poster of the ATLAS detector and an A5 fold out booklet that describes some of the big questions that researchers expect the LHC to answer. You can also download a poster describing the CMS detector (jpg 69kb) and a booklet describing the evolution of the universe (pdf 9.1mb) from the CMS area of CERN website. The ATLAS experiment has two posters available to download (or order) from the ATLAS store. Booklets, DVDs and other materials are also available. --Ashimjgec08 15:23, 24 May 2009 (UTC)#REDIRECT LHC#REDIRECT lhc