Scaremongers have warned that the collisions at Cern could unleash incalculable danger and perhaps even destroy the Earth. Michio Kaku puts some fears to rest

when pressed by journalists to flatly declare that the worst case scenario cannot occur, physicists shy away, not because we think the event might occur, but because of a loophole in the quantum theory. Because of Werner Heisenberg's uncertainty principle, there is a tiny chance that anything will occur. There is a chance that firebreathing dragons will be produced by the LHC. But the probability of this event is so small, one can show that it will not happen in the lifetime of the universe.