Time travel was once the stuff of fiction, but today it is discussed with utmost seriousness by Physicists. What are they saying about it: is time travel possible, impossible or something in between?
Trying to find the answer to this relies on Einstein’s General Relativity mixed with a dose of Quantum Mechanics, but once we are armed with these, can we find a way forward (and backward) into time?

Ian Stewart read Mathematics at Churchill College, Cambridge before completing his doctorate at the University of Warwick where he is now a Professor of Maths. He was the first recipient of the Christopher Zeeman medal and has held visiting professorships in the United States, Germany and New Zealand. He has given the Royal Institution Christmas lectures and is a fellow of the Royal Society. He was the Gresham Professor of Geometry between 1994 and 1998.