Hawking also proved the area theorem of black holes, that is, the area of black holes does not decrease with the increase of time. This naturally makes people associate the area of a black hole with the entropy of thermodynamics. ?
1973, he considered the quantum effect near the black hole, and found that the black hole would emit radiation like a blackbody, and the temperature of the radiation was inversely proportional to the mass of the black hole, so that the black hole would gradually become smaller because of the radiation, but the temperature was getting higher and higher, and finally it ended in a last-minute explosion. The discovery of black hole radiation is of great significance, which unifies gravity, quantum mechanics and statistical mechanics.
1974, his research turned to the theory of quantum gravity. Although people haven't got a successful theory, they have found some characteristics of it. For example, space-time is not flat on the Planck scale (10-33cm), but in a bubble state. There is no pure state in quantum gravity, the law of causality is broken, and the unknowability rises from classical statistical physics and quantum statistical physics to the third level of quantum gravity.
After 1980, his interest turned to quantum cosmology. The subtitle of A Brief History of Time is "From the Big Bang to the Black Hole". Hawking believes that the contribution of his life lies in that, within the framework of classical physics, the inevitability of black holes and big bang singularities has been proved, and black holes are getting bigger and bigger;
However, under the framework of quantum physics, he pointed out that black holes became smaller and smaller due to radiation, and the singularity of the Big Bang was not only smoothed out by quantum effects, but the whole universe also started from here. Hawking made it clear that he tried to understand the spirit of God. This makes the conclusion of all efforts so far even more surprising: the universe has no edge in space, no beginning and end in time, and the creator has done nothing.
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His outstanding point is that when I read his book A Brief History of Time at the age of 20, I really felt the beauty of physics. He made me believe that we can understand the mysteries of the universe, which will be a beautiful and pleasant thing.
Mr. Hawking is an outstanding scientist and a fighter who has been fighting diseases for a long time, and has made great contributions to science and mankind. Mr Hawking visited China three times before his death. China leaders met with him, and China scientists and science lovers had a pleasant exchange with him.
Mr Hawking cares about the development and construction of China, and he also speaks highly of China's scientific and technological progress. Mr Hawking also loves China culture very much. It was with his strong persistence and the help of his assistant that he finally climbed the Great Wall of China. We express our condolences and regrets for the unfortunate death of Mr. Hawking and our condolences to his family. I believe that Mr Hawking and his contribution will be remembered forever. (Comments by Foreign Ministry Spokesperson Lu Kang)
References:
Baidu Encyclopedia-Hawking