How the machines will take over

In recent months, several prominent champions of technology -- Bill Gates, Stephen Hawking, and Tesla founder Elon Musk among them -- have declared that the greatest threat to humankind is not climate change, nuclear warfare, religious fanaticism or bacterial superbugs. No, according to these famous forward-thinkers, the threat we should really be worried about is advanced artificial intelligence. That is, we should be worried about supersmart robots and computers guided by a globally networked über-entity that will one day be able to outlearn, outthink and outcompete the human species and send it hurtling toward extinction. Late last year, Hawking, a physicist, came right out and told the BBC: "The development of full artificial intelligence could spell the end of the human race." In a recent symposium at the Massachusetts Institute of Technology, Tesla's Musk said that creating advanced artificial intelligence was "summoning the demon."