Extract from The Book of Universes by John D. Barrow

The old gentleman walking down the street looked the same as ever—distinguished but slightly dishevelled, in a Bohemian style, a slow-walking European on an American main street, sad-faced, purposeful but not quite watching where he was going, always catching the attention of the locals as he made his way politely through the shoppers and the contra-flow of students late for lectures. Everyone seemed to know who he was, but he avoided everyone’s gaze.