Turns out Stephen Hawking, one of the world's premier theoretical physicists, is baffled by the popularity of the presumptive Republican presidential candidate in the United States.

Hawking — known for his ground-breaking discoveries on space-time, black holes, and quantum gravity — was asked by the hosts of the ITV show Good Morning Britain if he could explain the rise of Donald Trump.

"I can't," Hawking said in a prerecorded statement that will be broadcast Tuesday morning. "He is a demagogue who seems to appeal to the lowest common denominator."

Hawking also urged British residents to vote in favor of staying in the European Union on June 23, arguing that an exit would be economically damaging.

"Gone are the days when we could stand on our own against the world," he said.