If Hawking's theory is true, it might lead to the discovery of the "Theory of Everything" — the ultimate unifying theory to explain every physical aspects of the universe from black holes to magnetism.

"Black holes ain't as black as they are painted. They are not the eternal prisons they were once thought. Things can get out of a black hole, both to the outside, and possibly to another universe," Hawking said in a 2016 lecture. "So if you feel you are in a black hole, don't give up. There's a way out."

Hawking's humor, optimism, and uncanny ability to explain complex physics in plain words have inspired science lovers around the world.

Leonard Ng, 31 of Singapore, a doctor of engineering, said Hawking was an inspiration for many PhD students at Cambridge. "He's taught me tenacity, just to push on, mental discipline in general and to achieve the objectives I want in life especially academically," he said.

When the illustrated version of Hawking's 1988 Brief History of Time debuted in China in 2002, it sold faster than expected, said Wu Zhongchao, Hawking's former student and translator of the book. He is now a physics professor at Zhejiang University of Technology.

"Chinese media's and the public's obsession with Hawking was like nothing we had ever seen before," he said on the sidelines of the International Congress of Mathematicians in 2002, which Hawking also attended.