document: 20 October 2016 Last updated at 14:40 BST
  In a short speech, Prof Hawking said: "The rise of powerful AI will be either the best, or the worst thing, ever to happen to humanity. We do not yet know which."
  Read more: Stephen Hawking - will AI kill or save humankind?
summary: Prof Stephen Hawking has discussed the potential pitfalls of artificial intelligence, at an event in Cambridge marking the opening of the Centre for the Future of Intelligence.