Large Hadron Collider is activated

The team was holding its breath in the countdown to the switch-on after a series of technical hitches, including problems with the cooling system.

The £5 billion machine has been described as a 17-mile racetrack around which two streams of protons - building blocks of matter - run in opposite directions before smashing into one another. Reaching 99.99 per cent of the speed of light, each beam will pack as much energy as a Eurostar train travelling at 90 mph.

The flashes from the collisions may help scientists reproduce the conditions that existed during the first moments after the Big Bang at the birth of the universe.

Physicists hope to learn more about the origins of mass, gravity and mysterious dark matter.

But concerns have been voiced - in particular by the German chemist Professor Otto Rossler - that black holes created by the LHC will grow uncontrollably and “eat the planet from the inside”.