Millions of Chinese mourned the death on Wednesday of globally admired British theoretical physicist Stephen Hawking, 76, for his indomitable spirit and insightful probing of cosmic mysteries.

Netizens flooded Hawking's official Weibo account to bid farewell after the news broke in China around noon. They left more than 50,000 new comments in five hours under his last update, when he lauded young pop star Wang Junkai in November for caring about life beyond Earth.

"Cherish the memory of Mr Hawking. You forever belong to the stars and universe, and your teachings will forever be in my heart," Wang wrote, ending his sentence with a candle emoji.

News of Hawking's death quickly became the top-trending topic on Weibo and search engine Baidu. More than 380 million reads and 236,000 comments were generated on Weibo in the first five hours after the announcement.

Wang Jianyu, president of the Chinese Academy of Sciences Shanghai branch, said, "Hawking was truly an extraordinary man who gave birth to so many brilliantly innovative ideas in his so dreadful physical condition."

Hawking died of complications from amyotrophic lateral sclerosis, a degenerative disease of the nervous system that he defied for decades.

"The death of such a scientific giant is a great loss to the science community. But his thoughts and ideas will be carried on by future young scientists," Wang said. "As we mourn, science will continue to flourish."

Hawking's major scientific achievements included groundbreaking theories on the extreme conditions of black holes, super dense objects with gravity so strong that not even light can escape.

He hypothesized that black holes can emit particles and thermal radiation at an extremely slow rate near their edges, and thus can potentially evaporate. Scientists later named the theoretical emission "Hawking Radiation".

This theory thrilled scientists worldwide because it combined Einstein's General Theory of Relativity, which studies massive objects, with quantum mechanics, which deals in tiny particles, into a single, possibly observable cosmic event.

These two theoretical frameworks are the bedrocks of modern physics. So far, they have been shown to be accurate and essential in describing their own subjects, but are incompatible when used together, Hawking said.