Five ways AI might destroy the world: 'Everyone on Earth could fall over dead in the same second'

Artificial intelligence has progressed so rapidly in recent months that leading researchers have signed an open letter urging an immediate pause in its development, plus stronger regulation, due to their fears that the technology could pose "profound risks to society and humanity". But how, exactly, could AI destroy us? Five leading researchers speculate on what could go wrong. It has happened many times before that species were wiped out by others that were smarter. We humans have already wiped out a significant fraction of all the species on Earth.