As early as 16 years old, Einstein learned from books that light is a very fast electromagnetic wave. He has an idea. If a person moves at the speed of light, what kind of world scene will he see? He will not see the advancing light, but only the electromagnetic field that oscillates in space but stagnates. Is this possible?
In connection with this, he would like to discuss the so-called ether problem related to light waves. The word ether comes from Greece and is used to represent the basic elements that make up objects in the sky. /kloc-Descartes introduced it into science for the first time in the 0/7th century as a medium for spreading light. Later, Huygens further developed the theory of ether, thinking that the medium carrying light waves is ether, which should fill all spaces including vacuum and penetrate into ordinary matter. Unlike Huygens, Newton put forward the particle theory of light. Newton believed that the luminous body emitted a stream of particles moving in a straight line, and the impact of the particle stream on the retina caused vision. Newton's particle theory prevailed in18th century, but the wave theory prevailed in19th century, and the theory of ether developed greatly. At that time, the view was that the propagation of waves depended on the medium, because light can propagate in a vacuum, and the medium that propagates light waves is the ether that fills the whole space, also called optical ether. At the same time, electromagnetism has developed vigorously. With the efforts of Maxwell, Hertz and others, a mature electromagnetic phenomena's dynamic theory-electrodynamics was formed, which unified light and electromagnetic phenomena in theory and practice, and regarded light as electromagnetic waves in a certain frequency range, thus unifying the wave theory of light and electromagnetic theory. Ether is not only the carrier of light waves, but also the carrier of electromagnetic fields. Until the end of 19, people tried to find ether, but they never found it in the experiment.
But electrodynamics has encountered a big problem, which is inconsistent with the relativity principle followed by Newtonian mechanics. The theory of relativity existed as early as Galileo and Newton. The development of electromagnetism was originally included in the framework of Newtonian mechanics, but it encountered difficulties in explaining the electromagnetic process of moving objects. According to Maxwell's theory, the speed of electromagnetic waves in vacuum, that is, the speed of light, is a constant. However, according to the principle of speed addition in Newtonian mechanics, the speed of light in different inertial systems is different, which leads to a question: Is the principle of relativity applicable to mechanics applicable to electromagnetism? For example, there are two cars, one is approaching you and the other is leaving. You see the lights in the front car approaching you and the lights in the back car are far away. According to Maxwell's theory, the speed of these two kinds of light is the same, and the speed of the car doesn't work in it. But according to Galileo's theory, the measurement results of these two items are different. The car coming towards you will accelerate the light, that is, the speed of light in front of the car = speed of light+speed; Light leaves the car more slowly, because the speed of light behind the car = speed of light-speed of light. Maxwell and Galileo's statements about speed are obviously opposite. How can we resolve this disagreement?
Theoretical physics reached its peak in the19th century, but it also implied a huge crisis. The discovery of Neptune shows the incomparable theoretical power of Newtonian mechanics. The unification of electromagnetism and mechanics makes physics present a formal integrity, which is known as "a solemn and majestic architectural system and a touching and beautiful palace". In people's minds, classical physics has reached the point of near perfection. Planck, a famous German physicist, told his teacher when he was young that he would devote himself to theoretical physics. The teacher advised him: "young man, physics is a completed science, and there will be no further development." It is a pity to dedicate his life to this subject. "
Einstein seems to be the man who is going to build a brand-new physics building. During his stay in Berne Patent Office, Einstein paid extensive attention to the frontier dynamics of physics, thought deeply about many problems and formed his own unique views. During ten years of exploration, Einstein studied Maxwell's electromagnetic theory seriously, especially the electrodynamics developed and expounded by Hertz and Lorenz. Einstein firmly believes that the electromagnetic theory is completely correct, but there is one problem that makes him uneasy, and that is the existence of the absolute reference frame ether. He read a lot of books and found that all the experiments that proved the existence of ether failed. After Einstein's research, it was found that ether had no practical significance in Lorentz theory except as an absolute reference system and the load of electromagnetic field. So he thought: Is it necessary to have an absolute frame of reference? Do electromagnetic fields have to be loaded?
Einstein likes reading philosophical works and absorbing ideological nutrition from philosophy. He believes in the unity of the world and the consistency of logic. The principle of relativity has been widely proved in mechanics, but it cannot be established in electrodynamics. Einstein questioned the logical inconsistency between the two theoretical systems of physics. He believes that the principle of relativity should be universally established, so the electromagnetic theory should have the same form for each inertial system, but there is a problem of the speed of light here. Whether the speed of light is constant or variable becomes the primary question whether the principle of relativity is universally established. Physicists at that time generally believed in ether, that is, there was an absolute frame of reference, which was influenced by Newton's concept of absolute space. /kloc-At the end of 0/9, Mach criticized Newton's absolute view of time and space in Mechanics in Development, which left a deep impression on Einstein. 1905 One day in May, Einstein and a friend Bezo discussed the problem that had been explored for ten years. Bezo expounded his point of view according to Mahism, and they had a long discussion about it. Suddenly, Einstein realized something, went home and thought about it again and again, and finally figured it out. The next day, he came to Bezo's house again and said, thank you, my problem has been solved. It turned out that Einstein thought clearly about one thing: there is no absolute definition of time, and time is closely related to the speed of optical signals. He found the key to the lock, and after five weeks of hard work, Einstein showed people the special theory of relativity.
1905 On June 30th, the German Yearbook of Physics accepted Einstein's paper "On Electrodynamics of Moving Objects" and published it in September of the same year. This paper is the first article about special relativity, which contains the basic ideas and contents of special relativity. Special relativity is based on two principles: the principle of relativity and the principle of invariability of light speed. Einstein's starting point for solving problems is to firmly believe in the principle of relativity. Galileo first expounded the idea of relativity principle, but he did not give a clear definition of time and space. Newton also talked about relativity when he established the mechanical system, but he also defined absolute space, absolute time and absolute motion. He contradicts himself on this issue. Einstein greatly developed the principle of relativity. In his view, there is no absolute still space, and there is no absolute constant time. All time and space are connected with moving objects. For any reference system and coordinate system, there is only space and time belonging to this reference system and coordinate system. For all inertial systems, the physical laws expressed in space and time of the reference system are the same in form, which is the principle of relativity, strictly speaking, the principle of relativity in a narrow sense. In this article, Einstein did not discuss too much about taking the constant speed of light as the basis of the basic principle. It is a bold assumption that the speed of light is constant, which is put forward from the requirements of electromagnetic theory and the principle of relativity. This article is the result of Einstein's thinking about ether and electrodynamics for many years. At the same time, he established a brand-new space-time theory from the perspective of relativity, and gave a complete form of electrodynamics of moving objects on the basis of this new space-time theory. Ether is no longer necessary and ether drift does not exist.
What is the relativity of simultaneity? How do we know that events in two different places happen at the same time? Generally speaking, we will confirm by signal. In order to know the simultaneity of events in different places, we must know the speed of signal transmission, but why didn't we get this speed? We must measure the spatial distance between the two places and the time required for signal transmission. The measurement of spatial distance is simple, but the trouble lies in the measurement time. We must assume that every place has an aligned clock, and the propagation time of the signal can be known from the readings of the two clocks. But how do we know that the clocks in different places are right? The answer is that another signal is needed. Can this signal set the clock right? If we follow the previous thinking, it needs a new signal, so it will retreat indefinitely, and the simultaneity of different places cannot be confirmed. But one thing is clear, simultaneity must be associated with a signal, otherwise it is meaningless to say that these two things happen at the same time.
Optical signal may be the most suitable signal for a clock, but the speed of light is not infinite, which leads to a novel conclusion that two things happen at the same time for a stationary observer but not for a moving observer. Let's imagine a high-speed train, its speed is close to the speed of light. When the train passed the platform, A stood on the platform, and two lightning flashes appeared in front of A's eyes, one at the front end of the train and the other at the back end, leaving traces at both ends of the train and the corresponding parts of the platform. Through measurement, the distance between A and both ends of the train is equal, and the conclusion is that A saw two lightning flashes at the same time. Therefore, for A, two received optical signals travel the same distance in the same time interval and reach his position at the same time. These two things must happen at the same time, and at the same time. But for B in the center of the train, the situation is different, because B moves with the high-speed train, so he will intercept the front-end signal that propagates to him first, and then receive the optical signal at the back end. For B, these two events are different at the same time. In other words, simultaneity is not absolute, but depends on the observer's motion state. This conclusion denies the framework of absolute time and absolute space based on Newtonian mechanics.
Relativity holds that the speed of light is constant in all inertial reference frames, and it is the maximum speed at which an object moves. Due to the relativistic effect, the length of the moving object will become shorter and the time of the moving object will expand. However, due to the problems encountered in daily life, the speed of motion is very low (compared with the speed of light) and the relativistic effect cannot be seen.
Einstein established relativistic mechanics on the basis of completely changing the concept of time and space, pointing out that the mass increases with the increase of speed, and when the speed approaches the speed of light, the mass tends to infinity. He also gave a famous mass-energy relation: E=mc2, which played a guiding role in the later development of atomic energy.
The establishment of general relativity
1905, Einstein published his first article on the special theory of relativity, which did not immediately arouse great repercussions. But Planck, the authority of German physics, noticed his article and thought that Einstein's work could be comparable to Copernicus's. It is precisely because of Planck's promotion that relativity quickly became a topic of research and discussion, and Einstein also attracted the attention of academic circles.
1907, Einstein listened to his friend's suggestion and submitted the famous paper, and applied for the position of supernumerary lecturer at Federal Institute of Technology, but the answer was that the paper was incomprehensible. Although Einstein is very famous in the German physics field, in Switzerland, he can't find a teaching post in a university, and many famous people began to complain about him. 1908, Einstein finally got the position of supernumerary lecturer and became an associate professor the following year. 19 12 years, Einstein became a professor, 19 13 years, at the invitation of Planck, he became the director of the newly established Institute of Physics of Emperor William and a professor at Berlin University.
At the same time, Einstein is considering expanding the accepted theory of relativity. For him, there are two problems that make him uneasy. The first is the problem of gravity. Special relativity is correct for the physical laws of mechanics, thermodynamics and electrodynamics, but it cannot explain the problem of universal gravitation. Newton's theory of gravity is beyond distance, and the gravitational interaction between two objects is instantaneous, that is, at infinite speed, which conflicts with the view of field on which relativity is based and the limit of light speed. The second problem is the non-inertial system, and the special theory of relativity, like the previous physical laws, only applies to the inertial system. But in fact, it is difficult to find the real inertial system. Logically speaking, all natural laws should not be limited to inertial systems, and non-inertial systems must also be considered. It is difficult for special relativity to explain the so-called twin paradox. Paradoxically, there are two twins. My brother is traveling near the speed of light in a spaceship. According to the effect of relativity, the high-speed clock slows down. By the time my brother came back, he was very old, because he had been on the earth for decades. According to the principle of relativity, the spacecraft moves at a high speed relative to the earth, and the earth also moves at a high speed relative to the spacecraft. Brother looks younger than brother, and brother should look younger. This question can't be answered at all In fact, special relativity only deals with uniform linear motion, and my brother has to go through a process of variable speed motion to come back, which relativity can't handle. While people are busy understanding the relative special relativity, Einstein is accepting the completion of the general relativity.
1907, Einstein wrote a long article about the special theory of relativity, "On the Principle of Relativity and Its Conclusions". In this article, Einstein mentioned the principle of equivalence for the first time, and since then, Einstein's thoughts on the principle of equivalence have been developing continuously. Based on the natural law that the inertial mass is directly proportional to the gravitational mass, he proposed that the uniform gravitational field in an infinitely small volume can completely replace the frame of reference for accelerating motion. Einstein also put forward the view of closed box: no matter what method is used, the observer in closed box can't be sure whether he is still in the gravitational field or in the accelerating space without gravitational field. This is the most commonly used viewpoint to explain the equivalence principle, and the equality of inertial mass and gravitational mass is the natural inference of the equivalence principle.
1915438+01In June, Einstein submitted four papers to the Prussian Academy of Sciences. In these four papers, he put forward a new viewpoint, proved the precession of Mercury's perihelion, and gave the correct gravitational field equation. At this point, the basic problems of general relativity have been solved, and general relativity was born. 19 16 years, Einstein finished his long paper "The Basis of General Relativity". In this article, Einstein first called the theory of relativity that once applied to the inertial system as special relativity, and called the principle that only the physical laws of the inertial system are the same as the principle of special relativity as special relativity, and further expressed the principle of general relativity: for any moving reference system, the physical laws must be established.
Einstein's general theory of relativity holds that space-time will be curved due to the existence of matter, and the gravitational field is actually a curved space-time. Einstein's theory that space is bent by the sun's gravity well explains the unexplained 43 seconds in the precession of Mercury's perihelion. The second prediction of general relativity is gravitational redshift, that is, the spectrum moves to the red end in a strong gravitational field, which was confirmed by astronomers in the 1920s. The third prediction of general relativity is that the gravitational field deflects light. The gravitational field closest to the earth is the solar gravitational field. Einstein predicted that distant starlight would deflect 1.7 seconds if it passed through the surface of the sun. 19 19, encouraged by British astronomer Eddington, Britain sent two expeditions to observe the total solar eclipse in two places. After careful study, the final conclusion is that the starlight does deflect around the sun for 1.7 seconds. The Royal Society and the Royal Astronomical Society officially read out the observation report, confirming that the conclusion of general relativity is correct. At the meeting, Tang Musun, a famous physicist and president of the Royal Society, said, "This is the most significant achievement of gravity theory since Newton's time" and "Einstein's theory of relativity is one of the greatest achievements of human thought". Einstein became a news figure. 19 16, he wrote a book "On Special Relativity and General Relativity", which was reprinted 40 times by 1922, and was also translated into more than a dozen languages and widely circulated.
The significance of relativity
Special relativity and general relativity have been established for a long time. It has stood the test of practice and history and is a recognized truth. Relativity has a great influence on the development of modern physics and modern human thinking. Relativity logically unifies classical physics and makes it a perfect scientific system. On the basis of the principle of special relativity, special relativity unifies Newton's mechanics and Maxwell's electrodynamics, pointing out that both of them obey the principle of special relativity and are covariant to Lorentz transformation, while Newton's mechanics is only a good approximate law of low-speed motion of objects. On the basis of generalized covariation, general relativity establishes the relationship between local inertia length and universal reference coefficient through equivalence principle, obtains the generalized covariant forms of all physical laws, and establishes the generalized covariant gravity theory, and Newton's gravity theory is only its first-order approximation. This fundamentally solved the problem that physics was limited to the inertia coefficient in the past, and got a reasonable arrangement in logic. Relativity strictly examines the basic concepts of physics such as time, space, matter and motion, and gives the time-space view and material view of scientific system, thus making physics a perfect scientific system logically.
Special relativity gives the law of high-speed motion of objects, and puts forward that mass and energy are equivalent, and gives the relationship between mass and energy. These two achievements are not obvious to macroscopic objects moving at low speed, but they are extremely important in the study of microscopic particles. Because the speed of microscopic particles is generally relatively fast, and some of them are close to or even reach the speed of light, the physics of particles cannot be separated from relativity. The mass-energy relationship not only creates the necessary conditions for the establishment and development of quantum theory, but also provides the basis for the development and application of nuclear physics.
General relativity has established a perfect theory of gravity, mainly involving celestial bodies. Today, relativistic cosmology has further developed, and gravitational wave physics, compact astrophysics and black hole physics, which belong to relativistic astrophysics, have made some progress, attracting many scientists to study.
A French physicist once commented on Einstein: "Einstein will be at the forefront of physicists in our time." He is and will be one of the most outstanding superstars in the human universe. "In my opinion, he may be greater than Newton, because his contribution to science has entered the structure of the basic essence of human thought more deeply."
Respondents: Yaoge-Shusheng Grade 2 7-113:13.
Relativity is the basic theory about space-time and gravity, which was mainly founded by Einstein and divided into special relativity (special relativity) and general relativity (general relativity). The basic assumptions of relativity are the principle of invariance of light speed, the principle of relativity and the principle of equivalence. Relativity and quantum mechanics are two basic pillars of modern physics. Classical mechanics, which laid the foundation of classical physics, is not suitable for high-speed moving objects and objects under microscopic conditions. Relativity solves the problem of high-speed motion; Quantum mechanics solves problems under microscopic subatomic conditions. Relativity has greatly changed the common sense concepts of the universe and nature, and put forward new concepts such as simultaneous relativity, four-dimensional space-time and curved space.
Special relativity is a kind of relativity that is limited to the discussion of inertial system. Newton's view of time and space holds that space is a flat, isotropic and isotropic three-dimensional space-absolute space, and time is a single dimension independent of space (so it is absolute), that is, absolute view of time and space. Special relativity holds that space and time are not independent of each other, but a unified four-dimensional space-time whole, and there is no absolute space and time. In the special theory of relativity, the whole space-time is still flat, isotropic and isotropic, which is an ideal situation corresponding to the "global inertial system". Special relativity assumes that the speed of light in vacuum is constant, and Lorentz transformation can be deduced by combining the principle of special relativity and the above-mentioned space-time properties.
General relativity is a theory published by Einstein in 19 15. Einstein put forward the "equivalence principle", that is, gravity and inertia force are equivalent. This principle is based on the equivalence between gravitational mass and inertial mass (currently confirmed by experiments to be between 10? Within the precision range of 12, there is still no difference between gravitational mass and inertial mass). According to the principle of equivalence, Einstein extended the principle of relativity in a narrow sense to the principle of relativity in a broad sense, that is, the form of physical laws is unchanged in all reference systems. The motion equation of an object is the geodesic equation in the reference system. Geodesic equation has nothing to do with the inherent properties of the object itself, but only depends on the local geometric properties of time and space. And gravity is the expression of local geometric properties of time and space. The existence of material mass will cause the bending of time and space. In curved space-time, objects still move along the shortest distance (that is, along the geodesic-in Euclidean space). For example, the geodesic movement of the earth in curved space-time caused by the sun actually revolves around the sun, resulting in a gravitational effect. Just like on the surface of the earth, if you move in a straight line, you actually walk around the great circle on the surface of the earth.
Inverse Relativity: Relativity has also been criticized by many people, who think it is wrong and greatly hinders the development of society. However, this view is not accepted by the mainstream scientific community.
Einstein and his theory of relativity
In addition to quantum theory, an article entitled "On Electrodynamics of Moving Objects" published by Einstein in 1905 triggered another revolution in physics in the 20th century. This paper studies the influence of object motion on optical phenomena, which is another difficult problem faced by classical physics at that time.
/kloc-in the mid-9th century, Maxwell established the electromagnetic field theory and predicted the existence of electromagnetic waves propagating at the speed of light C. By the end of19th century, Maxwell's theory was completely confirmed by experiments. What is electromagnetic wave? To whom is its propagation speed c? At that time, the popular view was that the whole universe was full of a special substance called "ether", and electromagnetic waves were the propagation of ether vibration. But people find that this is a theory full of contradictions. If we think that the earth is moving in the static ether, then according to the principle of velocity superposition, the speed of light propagating in different directions on the earth must be different, but the experiment denies this conclusion. If we think that the ether was taken away by the earth, it is obviously inconsistent with some astronomical observations.
1887, Michelson and Morey made a very accurate measurement by using the interference phenomenon of light, but they still didn't find any movement of the earth relative to the ether. In this regard, H.A. Lorenz put forward a hypothesis that all objects moving in the ether should contract along the moving direction. From this, he proved that even if the earth moves relative to the ether, Michelson could not find it. Einstein studied this problem from a completely different way of thinking. He pointed out that all difficulties can be solved as long as Newton's concepts of absolute space and absolute time are abandoned, and there is no need for ether at all.
Einstein put forward two basic principles as the basis for discussing the optical phenomena of moving objects. The first is called the principle of relativity. That is to say, if the coordinate system K' moves at a constant speed relative to the coordinate system K without rotating, it is impossible to distinguish which coordinate system is K and which coordinate system is K' in any physical experiment made relative to these two coordinate systems. The second principle is called the principle that the speed of light is constant, which means that the speed of light c (in vacuum) is constant, and it does not depend on the moving speed of the luminous object.
On the surface, the constant speed of light seems to conflict with the principle of relativity. Because according to the classical law of mechanical speed synthesis, the speed of light should be different for the two coordinate systems, k' and k, which move at a relatively uniform speed. Einstein thought that if we want to admit that these two principles do not conflict, we must re-analyze the physical concepts of time and space.
The law of velocity composition in classical mechanics actually depends on the following two assumptions: 1. The time interval between two events has nothing to do with the motion state of the clock used to measure time; 2. The spatial distance between two points has nothing to do with the motion state of the ruler used to measure the distance. Einstein found that if the principle of light speed invariance and the principle of relativity are recognized to be compatible, then both hypotheses must be abandoned. At this time, the simultaneous events of one clock are not necessarily simultaneous for another clock, and they are relative at the same time. In two coordinate systems with relative motion, the values obtained by measuring the distance between two specific points are no longer equal. Distance is also relative.
If an event in the K coordinate system can be determined by three spatial coordinates X, Y, Z and a time coordinate T, and the same event in the K coordinate system is determined by X', Y', Z' and T', Einstein found that X', Y', Z' and T' can be solved by a set of equations. The relative velocity of the two coordinate systems and the speed of light c are the only parameters of the equation. This equation was first derived by Lorentz, so it is called Lorentz transformation.
Using Lorentz transformation, it is easy to prove that the clock will slow down because of movement, the ruler will be shorter when it is moving than when it is at rest, and the sum of speeds satisfies a new law. The principle of relativity is also expressed as a clear mathematical condition, that is, under the Lorentz transformation, the space-time variables X', Y', Z' and T' with apostrophes will replace the space-time variables X, Y, Z and T, and any expression of natural laws will still take the same form as before. What people call the universal law of nature is covariant for Lorentz transformation. This is very important for us to explore the universal laws of nature.
Besides, in classical physics, time is absolute. It has always played an independent role different from the three spatial coordinates. Einstein's theory of relativity involves time and space. It is believed that the real world of physics is composed of various events, and each event is described by four numbers. These four numbers are its space-time coordinates T and X, Y and Z, which form a four-dimensional continuous space, usually called Minkowski four-dimensional space. In relativity, it is natural to examine the real world of physics in a four-dimensional way. Another important result caused by special relativity is about the relationship between mass and energy. Before Einstein, physicists always thought that mass and energy were completely different and were separately conserved quantities. Einstein found that in the theory of relativity, mass and energy are inseparable, and the two conservation laws are combined into one. He gave a famous formula of mass and energy: e = mc2, where c is the speed of light. So quality can be regarded as a measure of its energy. Calculations show that tiny masses contain enormous energy. This wonderful formula has laid a theoretical foundation for mankind to obtain huge energy, make atomic bombs and hydrogen bombs, and use atomic energy to generate electricity.
Most physicists, including Lorenz, the founder of relativistic transformation relation, find it hard to accept these new concepts introduced by Einstein. The obstacle of the old way of thinking made this new physical theory not familiar to physicists until a generation later. Even in 1922, when the science prize was awarded to Einstein by the Royal Swedish Academy, it only said, "Because of his contribution to theoretical physics and because he discovered the law of photoelectric effect." Not a word about relativity.
Einstein further established the general theory of relativity in 19 15. The principle of relativity in a narrow sense is limited to two coordinate systems with uniform motion, while the principle of relativity in a broad sense cancels the restriction of uniform motion. He introduced an equivalence principle, arguing that it is impossible for us to distinguish between gravitational effect and non-uniform motion, that is, non-uniform motion and gravity are equivalent. He further analyzed the phenomenon that light will be bent by gravity when passing near a line, and thought that the concept of gravity itself was completely unnecessary. It can be considered that the mass of the planet makes the space around it curved, and the light takes the shortest path. Based on these discussions, Einstein derived a set of equations, which can determine the curved space geometry caused by the existence of matter. Using this equation, Einstein calculated the displacement of the perihelion of Mercury, which was completely consistent with the experimental observation, and solved a long-term unexplained problem, which made Einstein excited. In his letter to Erenfest, he wrote that this equation gives the correct value of perihelion. You can imagine how happy I am! For days, I was so happy that I didn't know what to do. "
1915165438+1On October 25th, Einstein submitted a paper entitled "Equation of Gravitation" to the Prussian Academy of Sciences in Berlin, which fully discussed the general theory of relativity. In this article, he not only explained the mystery of the perihelion motion of Mercury's orbit found in astronomical observation, but also predicted that the starlight would deflect after passing through the sun, and the deflection angle was twice that predicted by Newton's theory. The first world war delayed the determination of this value. 19 19 The total solar eclipse on May 25th provided people with the first observation opportunity after the war. Eddington, an Englishman, went to principe island on the west coast of Africa and made this observation. 165438+1On October 6th, Thomson solemnly announced at the joint meeting of the Royal Society and the Royal Astronomical Society that Einstein, not Newton, had proved this result. He praised "this is one of the greatest achievements in the history of human thought." Einstein discovered not an island, but a brand-new continent of scientific ideas. "The Times reported this important news under the title of" Revolution in Science ". The news spread all over the world, and Einstein became a world-famous celebrity. General relativity has also been elevated to a mythical sacred position.
Since then, people have shown more and more interest in the experimental test of general relativity. However, because the gravitational field of the solar system is very weak and the gravitational effect itself is very small, the theoretical result of general relativity deviates very little from Newton's gravitational theory, which makes the observation very difficult. Since 1970s, due to the progress of radio astronomy, the observation distance has far exceeded.