Scientist Geoffrey Hinton set out to understand the brain and ended up working with a group of researchers who invented a technology so powerful that even they don’t truly understand how it works. This is about a collision between two mysterious intelligences – two black boxes – human and artificial. Subscribe to Black Box, a new series on artificial intelligence, for more episodes. Help support our independent journalism at https://www.theguardian.com/infocus">theguardian.com/infocus