The possibility that alien life exists in the universe is among the most profound of human conjectures, which today is being investigated not just by science-fiction writers but by scientists.
Brian Clegg was always fascinated by Isaac Asimov's classic Foundation series of books, in which the future is predicted using sophisticated mathematical modelling of human psychology and behaviour. Only much later did he realise that Asimov's 'psychohistory' had a real-world equivalent: game theory.