KentuckyFC writes: "Just when you thought it was safe to switch on the LHC, another nightmare scenario has emerged that some critics believe could cause the particle accelerator to explode. The culprit this time is not an Earth-swallowing black hole but a "Bose supernova" in the accelerator's superfluid helium bath. Physicists have been playing with Bose Einstein Condensate or BECs for almost 20 years now. But in 2001, one group discovered that placing them in a powerful magnetic field could cause the attractive forces between atoms to become repulsive. That caused their BEC to explode in a Bose supernova, which was little more than a novelty when it was no more than a microscopic blob of cold matter. But superfluid liquid helium is also BEC. And physicists have suddenly remembered that the LHC is swimming in 700,000 litres of the stuff while zapping it by some of the most powerful magnetic fields on the planet. So is the LHC a Bose supernova waiting to go off? Not according to the CERN theory division which has published its calculations that show the LHC is safe (abstract). It also points out that no other superfluid helium handling facility has mysteriously blown itself to pieces."