Engineers checking the electronics of the cryogenic instrumentation under a dipole magnet
It’s the world’s biggest test-tube, and the most highly-anticipated physics experiment ever. On 10 September the most powerful particle accelerator on the planet goes fully into action for the first time.
The system has been 20 years in the making and has involved the work of thousands of scientists from 60 countries. The first beam of particles in the Large Hadron Collider (LHC) will begin to circulate around a 27-kilometre underground tunnel at CERN that lies beneath France and Switzerland.
The aim of this gigantic experiment is to recreate the conditions of the early universe, just a trillionth of a second after the Big Bang, and answer some deep questions about the strange world of subatomic particles.
Ten facts about the LHC and CERN
- When the 27-kilometre long circular tunnel was excavated, in an area between Lake Geneva and the Jura mountain range, the two ends met up to within one centimetre
- Each of the 6,400 superconducting filaments of niobium-titanium in the cable produced for the LHC is about 0.007 mm thick – which is about 10 times thinner than a human hair
- If you added all the filaments together they would stretch to the Sun and back five times, with enough left over for a few trips to the Moon
- The central part of the LHC is the world’s biggest fridge. At a temperature colder than deep outer space, it will contain iron, steel and the all important superconducting coils
- The pressure within the LHC’s beam pipes will be about 10 times lower than that on the Moon. This is an ultrahigh vacuum
- Protons at full energy in the LHC will be travelling at 0.999999991 times the speed of light. Each proton will go round the 27 km ring more than 11,000 times a second
- At full energy, each of the LHC’s two proton beams will have a total energy equivalent to a 400-tonne train travelling at 150 kilometres an hour
- The data recorded by each of the LHC’s big experiments will be enough to fill around 100,000 DVDs every year
- Despite some fears in the media, the scientists say the system is completely safe and will not be doing anything that has not happened “100,000 times over” in nature since the Earth has existed
- Tim Berners-Lee invented the World Wide Web while working at CERN almost two decades ago
Learn more
See a live webcast of the event
Watch Dara O’Briain talking about the experiment. Before becoming a broadcaster and comedian he studied maths and theoretical physics at UCD.
Read a safety statement from CERN about the experiment
Check out the Large Hadron Rap, written and performed by Kate McAlpine, who works in CERN’s press office
Read Tim Berners-Lee’s explanation to children of the origins of the Web
