Atom smashing

Back from holiday (two lovely rain-drenched weeks in Cornwall) to find the countdown has begun!

Just 20 days to go until "First Beam". The moment scientists at CERN in Geneva finally switch on the largest and most complex scientific experiment ever built, the Large Hadron Collider or LHC.

This giant atom smasher (sorry, particle collider) buried under the alps on the Swiss/French border will re-create the conditions that existed just a split second after the Big Bang. To do that the LHC fires two streams of protons in opposite directions around a ring bigger than London Underground's Circle Line. Travelling at velocities approaching the speed of light, and cooled to -271 degrees, the streams of protons are then crossed smashing into each other at fantastic energies.

The results, measured in four giant detectors around the ring, could help solve the most fundamental questions about the nature of the material world, reveal the secrets of dark matter, and even point the way to a theory of everything.

You'll hear a lot more about the project here on the Today programme and across Radio 4 over the coming weeks, and we'll be there live for the "big switch on" on September the 10th. 20 days and counting....