Stephen Hawking has said that he fails to understand the popularity of Donald Trump, the presumptive US Republican presidential candidate. ITV's Good Morning Britain asked the man who has widened the world's understanding of time, space, stars, galaxies and black holes if he could explain the popular appeal of the billionaire tycoon. Hawking, perhaps the world's most famous living scientist and the author of one of the world's best-selling books, replied: "I can't. He's a demagogue who seems to appeal to the lowest common denominator." He also ventured once again into political issues, appealing to British voters to back the remain campaign in the EU referendum on 23 June – not just for economic and security reasons, but for the sake of science as well.