The Large Hadron Collider

Find information about the world's most sophisticated and expensive science project

by Mark Hughes
Alice Checking

Two scientists checking equipment in the central tube of the LHC. Photo by Antonio Saba courtesy of CERN


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Taking 14 years to build at a cost of $8 billion, the world's largest and most powerful particle collider was activated for the first time in September 2008. Built outside Geneva by CERN Laboratories, an organization funded by 20 nations, the Large Hadron Collider (LHC) is the most expensive and sophisticated science project ever undertaken.

Super-smash up

Physicists will use the LHC to conduct experiments designed to enhance our understanding of the origin and evolution of the universe. One of the most anticipated experiments will involve re-creating the particles that were present about a trillionth of a second after the Big Bang. This primordial energy will be generated by accelerating protons—by electricity and magnetism—to great speeds along a tubular race track and then measuring the energy and reactions that are produced when the protons smash into each other. Such collisions occur all the time in nature; this is the first time such conditions will be reproduced in a laboratory setting.

Deep Underground

The race track of CERN's LHC is 17 miles long and is located 300 feet beneath the Swiss-French border. The length of this track will aid in accelerating trillions of protons to speeds exceeding 99.99% the speed of light. This means protons can travel 11,000 times around the 17-mile track in a single second, producing more than a billion head-on collisions.

Unsolved Mysteries

Physicists hope the LHC will help solve such mysteries as the origin of mass. At present, the mass of any object can be found easily, but answering the question of where mass itself comes from is elusive. Higgs particles, also called the Higgs Boson, have been theorized as the source of mass in the universe. Mathematical evidence for these particles has been an accepted and unifying feature of physics for the last quarter century, but direct evidence for the existence of these particles has been hard to come by. Physicists hope the LHC will provide the evidence to prove or disprove the Higgs theory once and for all. Others anticipate testing theories including dark matter, super symmetrical particles, and trans-dimensional particles.

Malfunction and a Spring Restart

A large helium leak on 23 September 2008 required a temporary shut down of the LHC. It is believed that the leak was caused by a faulty electrical connection between two of the accelerator's magnets. The temperature of the LHC is slowly being increased so that the magnets can be safely opened up for inspection—this will take three to four weeks. Since the time needed for this investigation abuts the LHC's scheduled winter maintenance period, restart of the LHC will occur sometime around early spring of 2009. It should be noted that problems such as these are to be expected with a cutting edge machine of this magnitude.

Will the LHC Destroy the World?

Prior to the activation of the LHC, some people voiced concern that it would destroy the world. Click here to read about the five most common fears about the LHC and reasons for why you should not be worried.

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