Someone asked a strange question: Why did Einstein think that gravity does not exist?
<h1 class= "pgc-h-arrow-right" > which is nonsense, a guess of a science blindness. </h1>
Einstein only traced the origin of gravity, used the field equation to explain the nature of gravity more brilliantly, and corrected some errors in Newtonian classical mechanics from the dynamic aspect, so that human understanding is closer to the real world.
Newton's law of universal gravitation is expressed as F=GMm/r².
That is to say, the magnitude of gravitational F is proportional to the product between the gravitational constant G and the interacting objects M and m, and inversely proportional to the distance between the centroids between the objects r square.
This law is still valid and is applied to many scientific studies and practices. For example, the three cosmic velocities are converted according to the law of gravitation.
Based on these three speeds, people can launch artificial celestial bodies and fly away from Earth's gravity to space.
< h1 class= "pgc-h-arrow-right" > Einstein's theory of general relativity reveals the essential properties of gravity. </h1>
Although Newton's law of universal gravitation reveals a force that is universal in this world, and it also derives the law of this force, he has not been able to explain what the source of this force is and why it exists.
Therefore, it stays at the level of knowing what it is and not knowing why it is so.
Don't look at this as just a step forward, but the conclusions reached can completely change the way humans perceive the world.
Einstein's general theory of relativity holds that mass is the root of gravity, and that the cause of gravitational force is the distortion of mass to surrounding space-time.
Just like a stone thrown into the water, or a fish swimming in the water, it will create ripples or whirlpools on the water, which will affect the surrounding material.
< h1 class= "pgc-h-arrow-right" > objects, regardless of size, will have this kind of space-time disturbance. </h1>
The phenomenon manifested by this perturbation is the space-time vortex or space-time trap, which affects the motion of objects in this range, resulting in the phenomenon of falling into each other's traps, and what we see is the mutual attraction of objects, which is gravity.
The gravitational pull of small-mass objects is very weak, so it is generally difficult to express and measure, and when it comes to large-mass objects, the gravitational force is very large.
The larger the mass of the celestial body, the larger and more violent the space-time vortex, and the small object will fall into the vortex when it passes, and it seems to be attracted to the large celestial body.
The curvature of space-time caused by the gravitational vortex of massive celestial bodies can even affect the light rays that pass through, such as the light of distant stars when passing near the Sun.
<h1 class= "pgc-h-arrow-right" > Einstein's prediction was confirmed by the scientific community shortly after the publication of general relativity. </h1>
In order to confirm the theory of the curvature of space-time, in 1919, the Royal Academy of Sciences sent two expeditions led by the famous astronomer Eddington, one to Principe, West Africa, and the other to the Amazon Forest, the two best observation sites for total solar eclipses, confirming Einstein's prediction.
Einstein predicted that starlight would pass by the edge of the Sun with a deviation of 1.74 arcseconds. But the sun's rays are too strong, and this deviation cannot be verified at all.
This phenomenon is only possible during a total solar eclipse, which is why Eddington led an expedition to the optimal total solar eclipse observation point, and their observations confirmed Einstein's prediction at the best moment of the total eclipse.
When Eddington telegraphed the news to Einstein, he simply said wittily: "I am not at all surprised, for it would be a pity for God if it were not detected." ”
This is the style of a master, the confidence of a master of science in his research results.
The astronomer Dyson announced in the Lecture Hall of the Royal Academy of Sciences: "After careful study of the negatives, I solemnly declare that they unquestionably confirm Einstein's prophecies. ”
The whole hall boiled over, and since then general relativity has spread all over the world, becoming the most basic and cutting-edge theory of modern physics.
According to the deduction of general relativity field theory, many predictions have been produced, such as black holes, gravitational waves, time expansion, gravitational lensing, etc., which have been confirmed one by one, and applied to space exploration and daily life, so that human scientific and technological civilization has risen to a new level.
< h1 class = "pgc-h-arrow-right" > what is the modifier of Einstein's theory of curvature of space-time for gravity? </h1>
The law of universal gravitation was derived by Newton under the guidance of a static cosmology, and is the embodiment of an absolute view of space-time. These theories are applicable in the low-speed system, and once you enter the high-speed system, there will be errors, and even miss thousands of miles.
Einstein's field theory tells us that gravity causes space-time to bend, and when this space is deformed, time changes, so space-time is relative, not absolute, in different coordinate systems.
At the same time, he introduced the time expansion effect in the high-speed system as early as special relativity, the faster the speed, the slower the passage of time; and in the gravity system, the greater the gravity, the slower the time flow will be.
The temporal expansion effect of velocity and the time expansion effect of gravity must be considered when we observe and move, otherwise our observation and long-distance voyage will not have accurate results.
Therefore, modern launch satellites and probes, as well as space navigation, must be modified in the relativity of space-time, otherwise it will lead to inaccurate navigation, impossible communication, and the probe spacecraft can not reach the destination.
<h1 class="pgc-h-arrow-right" > time dilation effect follows the following formula:</h1>
Special relativity velocity time expansion calculation formula: t'=t/√ [1-(v/c)²]
where t' is the velocity time expansion effect value; t is the first clock time record of the observer at low speed; v is the speed at which the second clock moves relative to the first clock; and c is the speed of light.
The general relativistic calculation formula for gravitational time expansion is: t'=tx√ (1-2GM/rc²)
Wherein, t' is the gravitational time expansion effect value, t is the time flow value of the low gravitational inertial system observer, G is the gravitational constant, the value is 6.67x10^-11N·m²/kg², M is the celestial mass, r is the celestial radius, and c is the speed of light.
The most typical example of use is the GPS navigation system. Because the navigation satellite is running at an altitude of more than 20,000 kilometers above the surface and at a speed of 14,000 kilometers per hour, it is smaller than the Earth in terms of gravity, so the satellite time is 45 microseconds faster than the surface of the earth, and at this speed, the time will pass 7 microseconds slower every day.
<h1 class = "pgc-h-arrow-right" > fold inside and out, 38 microseconds faster than the surface every day. </h1>
1 second is equal to 1000 microseconds, which is insignificant for our daily lives and can be completely ignored. But for a navigation system that requires precision, if it is not adjusted according to relativity, it will accumulate about 10 kilometers of positioning error every day, and such navigation will make you unable to find the north.
Therefore, for the atomic clocks on the satellite, it is necessary to adjust the vibration frequency so that the time of heaven and earth can be accurately consistent, so that it can be accurately positioned and navigated.
Therefore, Einstein's theory of relativity only more accurately understands the laws of the world, and he does not deny gravity, let alone "think" that gravity does not exist.
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