Originally Posted by Frosstbyte

Well, I mean, that's kind of the nature of experimentation, isn't it? We had no idea what would happen when we first discovered nuclear power or an internal combustion engine or fire, but we haven't destroyed the world with them (yet).

And furthermore, the only thing unique about this one is its size. There are many smaller ones around the wold which have been in use for years to no ill effect. If you want to have a crazy doomsday thing to worry about, worry about the Mayan long count calendar ending, because the LHC is not gonna give you much.