The world probably won't end today when scientists fire up their atom-smasher, despite popular belief that the 17-mile machine could create a black hole that will obliterate us all.

In fact, conditions approaching the doomsday scenario will only be apparent a couple of weeks from today, once the machine is tested and commissioned – which will start today.
Scientists at CERN (the European Organisation for Nuclear Research) are set to fire the first atoms into the Large Hadron Collider (LHC) today as they begin a weeks-long testing and commissioning cycle.
Once this is completed, they plan to speed sub-atomic particles through 17 miles of tunnels so that they smash together, hopefully replicating conditions that existed shortly after the "Big bang" the brought the universe into existence.
For just a split second, the collision will cause temperatures 100 000-times hotter than the sun.
Scientists are hoping that the experiment will unveil hundreds of new particles that will help them to bring new understanding to the field of particle physics.
They are hoping to uncover the Higgs Boson particle, which will help them explain how and why particles acquire mass.