Dark energy is supposed to make up two-thirds of the universe. But troublingly CERN has yet to find any evidence of it. Have we got our story of the universe wrong - might dark energy be the ether of our time? Do we need a new account of the universe, or is it too soon for such radical solutions?
Our very own mathematician Peter Cameron joins the debate, hosted by the BBC's Sue Nelson withTempleton Prize winning cosmologist George Ellis and Cambridge physicist David Tong.