Giant particle accelerator

Installation of the world's largest particle physics collider began yesterday beneath the Swiss-French border.

A 15m-long magnet weighing 35 tonnes was lowered into place, the first of 1232 of the same size that will be placed in the tunnel to speed subatomic particles around the 27km accelerator.

The aim is to make the particles - in this case protons - travel at nearly the speed of light until they collide, emitting a shower of even smaller particles that will reveal mysteries about the makeup of matter.

The US$1.8 billion ($2.4 billion) accelerator is being built by the European Organisation for Nuclear Research, known by the French initials CERN.