The Linac 2 (Linear Accelerator 2) is pictured at the European Organisation for Nuclear Research (CERN) in Meyrin near Geneva October 16, 2008. REUTERS/Denis Balibouse/FilesReuters - Dark matter, which scientists believe makes up 25 percent of the universe but whose existence has never been proven, could be detected by the giant particle collider at CERN, the research centre's head said Monday.