The guests on Hardtalk are people who do much to shape our world. More often than not they are a testament to the talent and potential of the human species. But what if we are living on the cusp of a new era shaped not by mankind but by machines using Artificial Intelligence to build a post-human world. Science fiction? Not according to scientist and philosopher Nick Bostrom who runs the Future of Humanity Institute. Stephen Sackur asks, when truly intelligent machines arrive, what happens to us?(Photo: Nick Bostrom, director of The Future of Humanity Institute)