David talks to Martin Rees about how we should evaluate the greatest threats facing the human species in the twenty-first century. Does the biggest danger come from bio-terror or bio-error, climate change, nuclear war or AI? And what prospects does space travel provide for a post-human future?
How did Facebook get to be so powerful and what, if anything, can we do to take some of that power back? David talks to John Naughton about the rise and possible fall of Mark Zuckerberg’s social media monolith.