Stephen Hawking has warned against Britain leaving the EU saying it would make us more "isolated and insular".
The theoretical physicist told Good Morning Britain that the UK needed to stay in the EU to protect its scientific research being undermined by Government austerity cuts.
Professor Hawking also warned that Britain would be "ultimately more remote from where progress is being made".
The Cambridge scientist said the mobility of people and grants given by the European Research Council to UK institutions were important reasons for Britons to vote to remain in the bloc on June 23.
Hawking was diagnosed with motor neurone disease in 1963 and given two years to live.
Instead, he wrote A Brief History of Time and became one of the world’s bestselling authors and most famous scientists.
He was also asked if Eddie Redmayne's portrayal of him in the film The Theory Of Everything had boosted his female fan base.
He replied: "I had many fans before Eddie Redmayne played me."
Asked if his knowledge of the universe meant he could explain the popular appeal of Donald Trump, he said it couldn't.
"He is a demagogue who seems to appeal to the lowest common denominator," he said.