You may be asking yourself, should we be worried when the LHC powers up and starts to conduct high-energy collisions? Just about every respected scientist in the concerning field has reviewed CERN's intentions and concluded there to be no problems. Einstein's work with relativity on the properties of gravity even predict that no black holes could be created by the LHC, however other higher-dimensional theories do exist which say otherwise . If accurate, the created black holes would be very small and unstable, not existing long enough to exhibit any negative macroscopic effect on the Earth. Even if they managed to remain stable, it would require an enormous amount of time to cause any damage. Aside from these facts a major reason for their confidence lies with Nature itself, cosmic rays of even higher energy make many such collisions every day and they of course have never been observed to cause any danger.