Last night, scientists at CERN (the European Center for Nuclear Research) turned on the Large Hadron Collider, the worlds largest particle accelerator located outside Geneva Switzerland. This experiment will send two protons going in opposite directions speeding around a circular ring 17 miles in circumference. The protons will then be smashed together and scientists will observe the reaction. The goal of this project is to find out answers about the makeup of matter and the origin of the universe. Specifically, scientists are hoping to find evidence for a theoretical particle called the Higg's Boson.
Here is a video that might help you understand the significance of the LHC: