Prof Stephen Hawking, one of Britain's pre-eminent scientists, has said that efforts to create thinking machines pose a threat to our very existence.
He told the BBC:"The development of full artificial intelligence could spell the end of the human race."
His warning came in response to a question about a revamp of the technology he uses to communicate, which involves a basic form of AI.
But others are less gloomy about AI's prospects.
The theoretical physicist, who has the motor neurone disease amyotrophic lateral sclerosis (ALS), is using a new system developed by Intel to speak.
Machine learning experts from the British company Swiftkey were also involved in its creation. Their technology, already employed as a smartphone keyboard app, learns how the professor thinks and suggests the words he might want to use next.
Prof Hawking says the primitive forms of artificial intelligence developed so far have already proved very useful, but he fears the consequences of creating something that can match or surpass humans.
"It would take off on its own, and re-design itself at an ever increasing rate,"...