A new monthly series invites leading commentators on the century to give their views on the landmark events that have changed the way we think and act. In the first programme, Manuel Castells, author of The Information Age and professor of sociology and city and regional planning at the University of Berkeley, California, talks to Peter Conrad about the wave of libertarianism in the sixties, the creation and collapse of Communism, and the impact of the technological revolution on how we pass information around the globe.