Professor Jim al-Khalili talks to Cern physicist Tejinder Virdee, about the search for the elusive Higgs boson, also known as the "God particle".
Last December, scientists working at the Large Hadron Collider caught a tantalising glimpse of the Higgs; but they need more data to be sure of its existence.
Twenty years ago, Tejinder set about building a detector within the Large Hadron Collider that's capable of taking 40 million phenomenally detailed images every second.
Finding the Higgs will validate everything physicists think they know about the very nature of the universe: not finding it, will force them back to the drawing board.
By the end of the year, we should know one way or the other.