the world 's largest atom-smashing machine is most famous for proving the existence of the higgs boson - but scientists hope it will now unlock even more fundamental secrets of the universe .
physicists at cern , the geneva-based organisation which runs the lhc , are aiming to see dark matter for the first time ever thanks to the device 's upgrade .
it was shut down two years ago - after confirming the discovery of the higgs boson - so that its energy levels could be almost doubled , allowing scientists to carry out more extreme experiments .