People in ancient times did not have a scientific understanding of the phenomena of nature. In the eyes of the ancients, all operations in this world were dominated by gods, so many myths and legends appeared. With the continuous progress and development of mankind, science has begun to sprout, and some wise men have begun to look at everything in this world with a scientific eye.

Speaking of the origin of human science, many people think of the Western world. Yes, science entered the human world from the West. Especially since the 17th century, Western science has made a qualitative leap, that is, the great scientist Newton. Put forward the law of universal gravitation.

Speaking of Newton, I believe my friends all know that such an inconspicuous daily phenomenon of an apple landing has attracted Newton’s attention. He thought: Why did Apple land instead of flying to the sky? Through constant thinking, the existence of gravity was discovered, which opened a new direction of exploration in human physics.

Newton deduced the mathematical expression of universal gravitation by observing the motion of celestial bodies and the motion of earth’s matter, combined with Kepler’s three laws of planetary motion. Gravity was discovered by Newton, and this discovery is of great significance to mankind. It opened a chapter for us to study the laws of the nature of matter.

According to the law of universal gravitation, as long as there is mass, there is gravitation between everything. The magnitude of gravitation is inversely proportional to the square of the distance and proportional to the mass. With the law of universal gravitation, we have also initially unveiled the laws of motion between galaxies and celestial bodies in the universe. Many people are curious, why can so many galaxies and celestial bodies in the universe be suspended and move very regularly? All the mysteries are related to gravity.

Gravity dominates all motions in the universe. Newton discovered the existence of gravitation, let us understand that the bridge between all things is gravitation. But what is the essence of gravity? Newton discovered gravity, but he didn’t explain to us: what exactly is gravity? How is it produced? Where did it come from?

From the discovery of gravity by Newton in the 17th century to the end of the 19th century, scientists have been exploring the nature of gravity for more than 200 years, trying to understand how this mysterious gravity comes from? If there has been no progress.

At the beginning of the 20th century, a great new star in the scientific world had risen, and he was Einstein. Einstein was also very curious about the nature of gravity. He didn’t recognize all the conjectures about the nature of gravity at that time. After exerting his imagination, he proposed the general theory of relativity.

The introduction of the general theory of relativity gave a major breakthrough in the issue of gravity and allowed scientists to find new directions for exploration. General relativity is actually a theory of gravitation, but it analyzes and studies the problem of gravitation from a completely different perspective.

Einstein believed that gravity is not a force in the traditional sense, but an effect derived from geometry. The theory of relativity tells us that the universe is not flat, but there is a bending phenomenon. We can imagine the universe as a film that can be compressed infinitely. Massive objects exist on this membrane. These massive objects will exert pressure on the cosmic membrane, thereby forming depressions, so that the surrounding objects will be bent. After the space structure is bent, the matter will follow the curved space. Movement, so the universal gravitation is shown.

Based on this principle, Einstein created the gravitational field equation, which can better describe various gravitational phenomena in the universe, surpassing Newtonâ€™s gravitational theory. For any theory to become the truth, it needs scientific experiment to prove it, so has Einstein’s gravitational field equation been proved by scientific experiment? Of course it is.

Through the new theory of gravity proposed by Einstein, scientists found that when a distant star passes near the sun, there will be a more obvious deflection phenomenon. According to the principle of relativity, this is because the mass of the star is larger and the space around it is more distorted. , So when the photon passes here, there will be a more obvious deflection motion, which is fully in line with the calculation results of general relativity.

Through the theory of relativity, Einstein also predicted other gravitational phenomena, such as the existence of black holes, gravitational waves, and gravitational time expansion effects. These gravitational phenomena have been confirmed one by one with the continuous advancement of human science and technology. Real photos of black holes were first released in 2019, and gravitational waves were actually detected by scientists in 2016.

These gravitational phenomena once predicted by the theory of relativity have now become reality one by one, which once again proves the correctness of the theory of relativity and the greatness of Einstein. Therefore, in the ranking of great scientists in the scientific world, Einstein won the first place, while Newton can only be ranked second.

So did Einstein find the essence of gravity? Can the theory of relativity fully explain the mystery of gravity? The answer is no. Although the theory of relativity is very great and allows us to understand the phenomenon of gravity from another level, it still has limitations and is not the ultimate theory of gravity. There are some gravitational phenomena that still cannot be explained by the theory of relativity, such as the problem of singularities, the quantum theory of the microcosm, etc.

The singularity is related to the origin of the universe, but what is the singularity? There is no definite answer yet. Only by truly understanding the nature of gravity can it be possible to truly understand the singularity problem. In addition, many phenomena in quantum mechanics completely subvert our cognition. The gravitational phenomenon in quantum is completely different from the macroscopic gravitational phenomenon, and it is impossible to explain quantum mechanics with the macroscopic gravitational theory.

Therefore, Einstein’s description of gravity is only an approximation to the essence of gravity. Although it is close to the essence of gravity, it is still some distance away from the true essence of gravity. It is not the ultimate theory of gravity. If it is the ultimate theory of gravity, then both the singularity problem and the quantum gravity problem in the micro world can be solved.

Einstein naturally understood that his theory of relativity had not completely solved the essence of gravity, so in his later years, he had been devoted to the research and exploration of the grand unified theory, but unfortunately he did not break through until his death. The Grand Unification Theory has always been the most mysterious and complicated problem in the current scientific community. If anyone can truly understand it, he may be able to surpass Einstein and sit on the throne of the leading scientific community.

On the road of research and exploration of the Grand Unified Theory, scientists have proposed a variety of conjectures, such as quantum gravity theory, string theory, etc. In the theory of quantum gravity, the graviton is very important. It is an elementary particle with no rest mass and the speed of light. However, until now, scientists have not found any evidence for the existence of gravitons.

String theory is even more lofty. Its basic point is that the basic unit of nature is not point particles such as electrons, photons, neutrinos, and quarks, but very small linear “strings.” String theory also puts forward the theory of multidimensional space, which believes that our universe is divided into 11 dimensions, and the space for human existence is only a three-dimensional universe.

String theory can perfectly decipher the essence of gravity. If its correctness can be proved, then the problem of the essence of gravity can be solved. At that time, human civilization will enter a new stage and become an advanced civilization in the universe. Unfortunately, string theory is completely contradictory to our current physical theory, and no evidence has been found to prove its correctness.

If string theory is correct, many things in modern physics will be completely overturned and will be rewritten. Therefore, for scientists, both hope that string theory is correct, but also hope that it is just a conjecture. Of course, the pace of science is constantly moving forward. Whether string theory is correct, as long as we have enough time, I believe there will be an answer in the future.