The Memory Business

Published: Dec. 29, 2011, 6:30 p.m.

Simon Schama reflects on how the world - ten years on - remembered the events of 9/11. And he ponders why it's vital to remember. "Ten years is an aeon in tweet-time", he writes, but 9/11 "bleeds - in every sense - into today's front pages".

Producer: Adele Armstrong.