Zhao Zheng of Beijing Normal University: The most unclear concept of physics is the concept of "time".

"Keeping your eyes open in search of the true nature of the universe has always been one of the most fundamental purposes of physics".

Brian Green, the leader of string theory, and Lee Smalling, the founder of cyclic quantum gravity, had to write such language in the face of his own "unified theory", as Brian Green said in "The Structure of the Universe": "Thoroughly understanding time and space has become the most timid challenge for physicists, and it is also the most popular prey" "Every direction of time, forward or backward, makes no difference in the laws, and this is the origin of a huge mystery." There is no distinction in the direction of time in the equations of fundamental physics, which is inconsistent with our daily experience".

Lee Smalling wrote in the foreword to "What is Time?" in the preface to The Rebirth of Time: "This question is deceptively simple, but it is incomparably important, and it bears the brunt of it in our exploration of the mysteries of the universe, from the big bang to the future of the universe, from the confusion of quantum physics to the great unity of forces and particles, all the problems facing physicists and cosmologists, in the final analysis, are asking: what is time?"

Similarly, in the book Quantum Space, Lee Smalling expresses his view of time: "The ubiquitous mathematical structure of quantum gravity theory leads us to conclude that time is an illusion." But the question is: "Whatever the meaning of the mathematical structure, there is no doubt that we are experiencing the passage of time."

"Seeing time as an illusion puts us in a series of cosmological conundrums. We cannot explain why the laws of physics take the form we see, nor can we judge the initial conditions that dominated the earliest states of the universe, but can only ponder the increasingly annoying fine questions of the laws of physics, or simply abandon the ship and flee to the chordal landscape, the eternal inflation, or the multiverse.

In this case, how can physics move forward? ”

The article is based on the national science and technology book documentation center "Probability analysis of time pattern and its estimation of constant A"