Revamped 'Big Bang' machine successfully restarts after 2 yr shutdown

The world's most powerful particle collider, that will allow physicists to explore uncharted areas of the dark matter that makes up the universe, was recently restarted after being turned off for two years during a major renovation project.

The Large Hadron Collider has restarted, with protons circling the machine's 27km tunnel for the first time since 2013, the BBC reported.

Particle beams have now travelled in both directions, inside parallel pipes, at a whisker below the speed of light.

Actual collisions will not begin for at least another month, but they will take place with nearly double the energy the LHC reached during its first run.

Scientists hope to glimpse a "new physics" beyond the Standard Model.

The experiment teams have already detected "splashes" of particles, which occur when stray protons hit one of the shutters used to keep the beam on-track. If this happens in part of the pipe near one of the experiments, the detectors can pick up some of the debris.

The LHC allows beams containing billions of protons travelling at 99.9 per cent the speed of light to shoot through the massive collider in opposite directions.

Powerful magnets bend the beams so that they collide at points around the track where four laboratories have batteries of sensors to monitor the smash-ups.

The sub-atomic rubble would then be scrutinized for novel particles and the forces that hold them together.

More than 10,000 scientists work directly or indirectly on the LHC's four experiments, while the facility itself operates on a budget of nearly 1.5 billion dollars a year.