Adam Rutherford presents a special tribute to the science of Stephen Hawking. He is joined by Fay Dowker, a former PhD student of Hawking and now a professor of theoretical physics at Imperial College, Professor Carlos Frenk, a long-time colleague and friend and fellow physicist and science communicator Professor Brian Cox. They look at the scientific legacy of Stephen Hawking and the role that his work played in bringing us a step closer to a single grand theory that explains how the universe works.