The Large Hadron Collider (LHC) is a particle accelerator and hadron collider located at CERN, near Geneva, Switzerland (46°14′N, 6°03′E). Currently under construction, the LHC is scheduled to begin operation in May 2008. The LHC is expected to become the world's largest and highest-energy particle accelerator.
When in operation, about seven thousand scientists from eighty countries will have access to the LHC, the largest national contingent of seven hundred being from the United States. Physicists hope to use the collider to test various grand unified theories and enhance their ability to answer the following questions:
Is the popular Higgs mechanism for generating elementary particle masses in the Standard Model realised in nature? If so, how many Higgs bosons are there, and what are their masses?
Will the more precise measurements of the masses of the quarks continue to be mutually consistent within the Standard Model?
Do particles have supersymmetric ("SUSY") partners?
Why are there apparent violations of the symmetry between matter and antimatter? See also CP-violation.
Are there extra dimensions indicated by theoretical gravitons, as predicted by various models inspired by string theory, and can we "see" them?
What is the nature of dark matter and dark energy?
Why is gravity so many orders of magnitude weaker than the other three fundamental forces?
Not to worry:
Concerns have been raised that performing collisions at previously unexplored energies might unleash new and disastrous phenomena. These include the production of micro black holes, and strangelets. Such issues were raised in connection with the RHIC accelerator, both in the media and in the scientific community; however, after detailed studies, scientists reached such conclusions as "beyond reasonable doubt, heavy-ion experiments at RHIC will not endanger our planet"