According to Einstein's theory of relativity, gravity will slow down time. Therefore, when we approach a black hole, time will indeed slow down due to the strong gravitational effect, and it may even be within a certain range when we approach a black hole. One second has passed, and the outside world has passed 100 years.
If the clock is placed in a place with weak gravity (such as the earth), it is difficult (but still possible) to measure the influence of gravity on time. But if the clock is placed in a place with strong gravity, such as a black hole, the influence of gravity on time can be seen immediately, and the influence varies according to the position of the observer. For a space traveler who falls into a black hole, the increase of gravity will accelerate his cognition of things; He will feel that he was sucked in by a black hole and suddenly reached the "bottom". But for observers who are far away from and unaffected by black holes, the situation is just the opposite. In their eyes, the unfortunate astronaut seems to be moving very slowly. It seems that the closer he is to the black hole, the slower he moves. The reason is that according to the prediction of relativity, the strong gravity of black holes will slow down time. So it seems that astronauts have never fallen to the bottom. At the bottom, all the mass and energy are condensed into a tiny point, space disappears and time stops. All the physical laws that should be applied to the outside world in a black hole have come to an end, so we have no way of knowing what it is like in a black hole.
Schwarzenegger, a scientist, worked out a range in which time and various physical phenomena are different from the outside world. For example, time is slow and gravity is heavy. Because Schwarzenegger worked it out, it is called schwarzschild radius interface, also called event horizon.
Event horizon refers to the state that the time in a black hole is completely different from the outside world. Because light is pulled by gravity, a minute in a black hole may be equal to decades outside. For example, if you are sucked into a black hole now, you will be crushed in one minute. But maybe after a few seconds, you will see others being sucked into the black hole, but it was actually inhaled decades later. ...
/kloc-In the late 9th century, scientists thought that their complete description of the universe was coming to an end. They imagine that space is full of a continuous medium called "ether". Just like sound waves in the air, light and electromagnetic signals are waves in the ether.
However, the opposite result to the view that space is full of "ether" soon appeared: according to the theory of "ether", the propagation speed of light should be a constant value relative to "ether", so if you are in the same direction as the propagation of light, the speed of light you measure should be lower than that you measure at rest; On the contrary, if you travel in the opposite direction to the direction of light propagation, then the speed of light you measure should be higher than that you measure at rest. However, a series of experiments found no evidence of the difference in light speed.
Among these experiments, Ahlport Michelson and Eddie Ward Murray of the Case Institute in Cleveland, Ohio, USA made the most accurate and detailed measurement in 1887. They compared the propagation speeds of two right-angle beams. Because it rotates around the axis of rotation and revolves around the sun, according to reasoning, the earth should pass through the "ether", so the above two beams of light at right angles should be measured at different speeds due to the movement of the earth. Murray found that the speed of two beams of light is different whether it is day or night or winter or summer. Whether you exercise or not, light always seems to travel at the same speed relative to you.
Irish physicist George Fitzgerald and Dutch physicist Hen Zhuo Ke Lorenz first thought that the size of an object moving relative to the "ether" would shrink in the direction of motion, while the clock moving relative to the "ether" would slow down. As for "ether", Fitzgerald and Lorenz thought it was a real substance.
At this time, a young man named Ahlport Einstein, who works in the Swiss Patent Office in Bern, the capital of Switzerland, intervened in the theory of "ether" and solved the problem of the speed of light once and for all.
Einstein pointed out in the article 1905 that the whole concept of "ether" is redundant because you can't detect whether you are moving relative to "ether". On the contrary, Einstein believed that the laws of science should have the same form for all free-flowing observers. No matter how the observer moves, he should measure the same speed of light.
Einstein's idea requires people to give up all the common concepts of clock measuring time. Thus, everyone has his own time value: if two people are relatively static, then their time is the same; If there is mutual movement between them, then their observation time is different.
A large number of experiments have proved that Einstein's idea is correct. An accurate clock rotating around the earth is really different from the accurate clock stored in the laboratory in terms of time indication. If you want to prolong your life, you can fly east by plane, which can superimpose the speed of the earth's rotation. Anyway, you can get a life extension of a few seconds, and you can also make up for the damage caused by eating aviation food.
Einstein's premise is that the laws of nature are the same for all observers who move freely, which is the basis of relativity. The reason is that this premise means that only relative motion is important. Although the perfection and conciseness of the theory of relativity have convinced many scientists and philosophers, there are still many opposing opinions. Einstein abandoned two absolute concepts of natural science in the19th century: absolute stillness implied by "ether" and absolute or cosmic time measured by all clocks. People can't help asking: does relativity mean that everything is relative and there will be no conceptual absolute standard?
This anxiety lasted from the 1920s to the 1930s. 192 1 year, Einstein won the nobel prize in physics for his contribution to the photoelectric effect. However, due to the complexity and controversy of the theory of relativity, the Nobel Prize was awarded without mentioning the theory of relativity.
Until now, I still receive two or three letters a week telling me that Einstein was wrong. Nevertheless, the theory of relativity has now been fully accepted by the scientific community, and its predictions have been confirmed by countless experiments.
An important result of relativity is the relationship between mass and energy. Einstein assumed that all observers have the same speed of light, which means that nothing can travel faster than the speed of light. What happens if particles or spacecraft are constantly powered? The mass of the accelerated object will increase, and it is difficult to accelerate any more. It is impossible to accelerate a particle to the speed of light because it needs infinite energy. The equivalent relationship between mass and energy was summed up by Einstein in his famous mass-energy equation "E = mc2", which is perhaps the only physical equation that can be known by women and children in the street.
When the uranium nucleus splits into two small nuclei, huge energy will be released due to tiny quality defects. This is one of the many conclusions of the mass-energy equation. During the period of 1939, World War II was overcast. A group of scientists who realized the application of fission reaction persuaded Einstein to overcome his scruples as a pacifist and wrote a letter to then US President franklin delano roosevelt, persuading the United States to start a nuclear research program, which led to the Manhattan Project and the explosion of the atomic bomb over 1945 Hiroshima. Some people blame Einstein for discovering the relationship between mass and energy because of the atomic bomb, but this kind of blame is just like blaming Newton for discovering gravity because of a plane crash. Einstein didn't participate in any process of the Manhattan Project and was frightened by the huge explosion.
Although relativity is perfectly combined with the relevant laws of electromagnetic theory, it is incompatible with Newton's law of universal gravitation. Newton's theory of gravity shows that if you change the distribution of matter in space, the gravitational field of the whole universe changes at the same time, which not only means that you can send signals that travel faster than the speed of light (which is not allowed by relativity), but also requires an absolute or universal concept of time, which is abandoned by relativity.
Einstein knew this incompatible difficulty from 1907, when he was still working in the patent office in Bonn, but he didn't think deeply about it until 19 1 1, when Einstein was working in Prague, Germany. Einstein realized the close relationship between acceleration and gravity field. A person in a sealed compartment can't tell whether his own pressure on the floor is because he is in the gravity field of the earth or because he is accelerated by a rocket in a weightless space. All this happened before the era of Star Trek. Einstein thought people were in elevators, not in spaceships. But we know that if you don't want the elevator to collide, you can't accelerate or fall freely in the elevator for a long time. If the earth is completely flat, people can say that the apple fell on Newton's head because of gravity, which is equivalent to Newton's head hitting the apple because Newton and the earth's surface accelerated. However, on the premise that the earth is round, the equivalent relationship between acceleration and gravity no longer holds, because people on the opposite side of the earth will be accelerated in the opposite direction, but the distance between the observers on both sides will remain the same.
19 12 years, when he returned to Zurich, Switzerland, Einstein was inspired. He realized that if some adjustments were introduced into real geometry, the equivalent relationship between gravity and acceleration could be established. Einstein imagined what would happen if the space-time entity formed by the three-dimensional space and the fourth-dimensional time was curved? His idea that mass and energy will bend space-time may have been proved in some ways. Like planets and apples, objects tend to move in straight lines, but their trajectories seem to be bent by gravity because space-time is bent by gravity.
With the help of his friend Marshall Grossman, Einstein learned the theory of curved space and surface. When bernhard Lehman developed these abstract theories, he never thought that they would be related to the real world. 19 13 years, in an article jointly published by Einstein and grussmann, they put forward a view that gravity as we know it is only an expression of the fact that space-time is curved. However, due to Einstein's mistakes (Einstein is a real person and can make mistakes), they failed to find out the relationship equation between the curvature of space-time bending and the energy quality contained in it.
When he was in Berlin, Einstein continued to study this problem. He has no family disputes and is basically unaffected by the war. 1915438+01June, Einstein finally discovered the equation of the relationship between space-time curvature and the energy quality contained in it. 19 15 In the summer, during his visit to the University of G? ttingen, Einstein discussed his ideas with mathematician David Hilbert, who discovered the same equation a few days earlier than Einstein. However, as Hilbert admitted, the honor of this new theory belongs to Einstein, who linked gravity with curved space-time. We should also thank civilized Germany, because it is precisely because of it that such scientific discussions and exchanges can still be carried out without being affected during the war at that time, which is in great contrast with what happened 20 years later (referring to World War II, editor's note)!
The new theory of curved space-time is called "general relativity" to distinguish it from the original theory that does not contain gravity, and it has been renamed "special relativity". 19 19, the "general theory of relativity" was proved in a rather grand form: at that time, a British scientific expedition to West Africa observed the tiny movement of a star close to the sun in the sky during the solar eclipse. As Einstein predicted, the light emitted by a star will be bent by the sun's gravity when it passes near the sun. This is direct evidence to prove curvature of spacetime. Since 300 BC, Euclid completed his "The Elements", which is the greatest revolutionary update for human beings to perceive their existence in the universe.
Einstein's "general relativity" changed "time and space" from a passive event background to an active participant in a dynamic universe, which led to great difficulties in the frontier of science and remained unsolved at the end of the 20th century. The universe is full of matter, which in turn leads to the bending of space-time and brings objects together. When explaining the static universe with "general relativity", Einstein found that his equation had no solution. In order to adapt his equation to the static universe, Einstein added a term called "cosmological constant", which bends space-time again to separate all objects. The repulsive effect introduced by the cosmological constant will balance the mutual attraction of objects and allow the long-term balance of the universe.
In fact, this has become one of the biggest opportunities lost by human beings in the history of theoretical physics. If Einstein continues to work in this direction instead of introducing the "cosmological constant" flexibly, he may be able to predict whether the universe is expanding or contracting. However, it was not until the 1920s, when the 100 inch planetarium on Mount Wilson observed that galaxies farther away from us were moving away from us at a faster speed, that we began to seriously consider the possibility of the universe changing with time. In other words, as time goes on, the universe is expanding and the distance between any two galaxies is increasing steadily. Einstein later called "cosmological constant" the most serious mistake in his life.
"General relativity" has completely changed the discussion direction of the origin and destination of the universe. The static universe may exist forever, or at some point in the past, when it was born, it was already in its present form. On the other hand, if galaxies are moving away from each other now, they should have been close to each other in the past. About 654.38+0.5 billion years ago, they may even touch and overlap each other, and their density may be infinite. According to the general theory of relativity, the Big Bang marked the origin of the universe and the beginning of time. In this sense, Einstein is not only the greatest figure in the past 100 years, but also deserves people's respect for a longer time.
In a black hole, space and time are so curved that the black hole absorbs all the light and no light can escape. "General relativity" therefore predicts that time should end in a black hole. However, the equation of general relativity does not apply to the two extreme cases of the beginning and end of time. So this theory can't reveal what happened in the Big Bang. Some people think that this is a symbol of God's omnipotence, and God can create the universe in the way he wants.
But others (including myself) think that the origin of the universe should obey a universal principle that holds true at all times. We have made some progress in this direction, but we are still far from fully understanding the origin of the universe. The reason why general relativity can't be applied to the Big Bang is that it is incompatible with another great conceptual breakthrough in the early 20th century-quantum theory. Quantum theory was first put forward in 1900. Max Planck, who worked in Berlin at that time, found that the radiation emitted by red-hot objects could be interpreted as the light emitted by energy units of a specific size. Planck called this unit of energy a quantum. For example, radiation is like bags of sugar. In the supermarket, you can't buy as many as you want. You can only buy a kilo set meal. In a paper written by Einstein in 1905, Planck's quantum hypothesis may explain the photoelectric effect, that is, some metals release electrons when they receive light. This effect is the basis of modern photo detectors and TV photography applications, so Einstein won the Nobel Prize of 192 1.
Einstein studied the concept of quantum until the 1920s, when Werner Heisenberg of Copenhagen, paul dirac who built the bridge and Evan Schrodinger of Zurich put forward the quantum mechanism, thus showing a new picture of reality. According to their theory, small particles no longer have a certain position and speed. On the contrary, the more accurate the position of small particles is, the less accurate their velocity measurement is. or vice versa, Dallas to the auditorium
Einstein was so confused about the arbitrariness and unpredictability in this basic law that he finally failed to accept the quantum mechanism. His famous motto "God does not roll the dice" expresses this feeling. Nevertheless, most scientists have accepted the new laws of quantum mechanism and acknowledged their applicability, because these laws not only agree well with the experimental results, but also can explain many previously unexplained phenomena. These laws have become the basis of the development of contemporary chemistry, molecular biology and electronics, and also the cornerstone of science and technology that has changed the whole world for half a century.
1933, when the Nazis ruled Germany, Einstein left the country and gave up his German citizenship. He spent the last 22 years of his life at the Institute for Advanced Science in Princeton, New Jersey. Natri launched a movement against "Jewish science" and Jewish scientists (expelling Jewish scientists is one of the reasons why Germany can't build an atomic bomb), and Einstein and his theory of relativity are the main goals of this movement. When told that a book named 100 Scientists Against Einstein had been published, Einstein replied, why 100? One is enough to prove that I am wrong, if I am really wrong.
After World War II, he urged the allies to establish a global organization to control nuclear weapons. 1952, he was awarded the presidency by the newly established Israel, but he refused. "Politics is temporary," he wrote. "Equations are eternal." The equation of general relativity is his best epitaph and monument. Together with the universe, they will never decay.
In the past 100 years, the world has experienced unprecedented changes. The reason is not politics or economy, but science and technology-science and technology directly derived from advanced basic scientific research. No scientist can better represent the advanced nature of this science than Einstein. (This article is slightly abridged)
As early as 19 19, Einstein promised to award the Nobel Prize to his Serbian wife mileva Mariko. At that time, Einstein was convinced that he would win the Nobel Prize, but he didn't think it was because of his contribution to the photoelectric effect.
Note 2 StarTrek is a TV series that is being broadcasted in America.
Note 3 mileva Mariko accompanied Einstein to Berlin at first, then left immediately, took their two sons back to Switzerland, and divorced three years later. After Einstein married his divorced cousin elsa, who had a daughter at that time, elsa gave Einstein meticulous care and accompanied him through the years of exploring "general relativity". Mariko contributed to Einstein's "Special Theory of Relativity", but she never mentioned that she was engaged in teaching mathematics and physics after her divorce.