An extremely rare manuscript written by Albert Einstein and a close friend in 1913 was sold by Christie’s auction house today. The 54-page document provides a rare insight into how Einstein came up with the theory of relativity. Marco Werman talks to theoretical physicist Lee Smolin of the Perimeter Institute for Theoretical Physics at the University of Waterloo in Ontario, Canada, about what the 108-year-old manuscript tells him about the thought process and work habits of his intellectual hero.