The preparations are almost complete: the largest particle accelerator in the world,the Large Hadron Collider or LHC,is due to be reactivated after a year of repairs. CERN calls the LHC the largest experiment in the world,with 10,000 scientists from a host of countries working to make it possible.The heart of the machine is a 27 kilometer long ring of magnets that will smash protons together with such force that new sub-atomic particles can be created. Scientist are hoping the three billion euro endeavor will help shed light on some of the most puzzling questions of modern physics.