null: Professor Brian Cox takes an audience of celebrity guests, including Charles Dance and Rufus Hound, and members of the public on a journey into the wonderful universe of the Doctor, from the lecture hall of the Royal Institution of Great Britain. Drawing on the latest theories as well as 200 years of scientific discoveries and the genius of Einstein, Brian tries to answer the classic questions raised by the Doctor - can you really travel in time? Does extra-terrestrial life exist in our galaxy? And how do you build something as fantastical as the TARDIS?