Black Hole Gonna Eat You. Possibly.

Here's the ATLAS detector from the Large Hadron Collider (LHC) - there's a man standing at the bottom of the picture - which is the particle accelerator thing at CERN in France/Switzerland that smashes protons together.

This ATLAS detector bit is the worlds largest superconducting magnet. To test it, they cooled it down over a six-week period last year to reach –269°C . It was then powered up reaching 21 thousand amps. Afterwards, the current was switched off and the stored magnetic energy of 1.1 GigaJoules, the equivalent of about 10,000 cars travelling at 70km/h, was safely dissipated. I think it measures particle mass by seeing how much their path is deflected.

Anyway, the LHC is really powerful and I think it gets switched on in November if they get their finger out. People inside and outside of the physics community have voiced concern that the LHC might trigger one of several theoretical disasters capable of destroying the Earth or even our entire Universe, including the creating of stable black holes. The CERN people were nice enough to commision a report you can read and they think it's unlikely.

They conclude "no basis for any conceivable threat".