Questions about Einstein s theory of relativity

The main points of special relativity:

1) The principle of special relativity (principle of special covariance): all inertial frames of reference are equal, that is, the form of physical laws is the same in any inertial frame of reference. This means that the laws of physics are the same for an observer at rest in a laboratory as for an electron moving at high speed and uniform speed relative to the laboratory.

The earliest experiments in support of special relativity were the Michelson-Morey experiments, which confirmed that the speed of light was constant. Placing an atomic clock on an airplane and disturbing the earth and comparing it with a clock on the ground proved the time dilation effect predicted by special relativity. Today, particles moving at high speed are used in countless fields, and they can be considered as the verification of the theory of relativity.

The main points of general relativity:

1) Equivalence principle: The inertial mass is equivalent to the gravitational mass. One conclusion of this principle is that any point in space-time in the gravitational field is equivalent to an accelerating non-inertial frame.

2) The gravitational effect can be seen as the curvature of space-time.

Experimental arguments for general relativity are:

1.Light bending, measured by Eddington (1919 solar eclipse). But then it became known that there was something wrong with this measurement.

In 2004, the Cassini satellite flew to Saturn to measure the bending of radar waves, verifying the bending effect of light, which is consistent with the accuracy predicted by general relativity within 1/1000.

2.The movement of Mercury's today's point deviates from the calculations of Newtonian mechanics, but it agrees well with the results of general relativity.

No scientific theory can confirm or falsify the existence of God, which are two completely different sets of knowledge. As science has developed, the territory of "God," who is believed to hold the truth, is actually getting smaller and smaller (but perhaps never to be smaller). Einstein once brought out God to illustrate some problems (does God roll dice), and other scientists have also done this kind of thing (Pauli doesn't believe in Tsung-Dao Lee, Yang Chenning's theory of non-conservation of universal symmetry, saying that he doesn't believe that God is left-handed), and even the higgs particles that the current particle experiments are keen to find have been called God particles (in fact, they were originally called goddman particles, which means damn particles, and for some reason, damn them became God), but the so-called physicists have legends related to God, It's basically just a joke.

Special relativity is to explain the microscopic low-speed motion negates the ether theory, and general relativity is to explain the relationship between space and time, it does not recognize gravity, in general relativity believes that all gravitational phenomena are caused by the curvature of space-time. God Questions? He should have said "God doesn't roll the dice" Einstein was a Jew and an atheist, and he was talking about Heisenberg's uncertainty theorem and Pauli's incompatibility principle!

This can only explain and describe a theory, but it is not really logical reasoning.

The frame of reference you are talking about is the set of classical mechanics, that is, macroscopic physics. Love is microscopic physics, and it doesn't apply to this!

No, your understanding of the theory of relativity is a bit problematic.

Yes, Einstein's theory of relativity is based on the assumption that the speed of light is absolute, not relative.

This may be abstract, but I'll give you an example, if you have two trains running together, their relative velocity to each other should be 0, right? Okay, at this time, there is a light on the front of one train, so what is the speed of the light seen by the people on the other train? Quite simply, it's the speed of light.

This is easy to understand. The question is, what is the speed of light seen by a person standing on the ground? Should it be the speed of the train plus the speed of light?

Wrong, Einstein told us, or the speed of light. That is, the speed of light is absolute and not under any frame of reference.

Don't ask why, Einstein didn't tell us why, it's like Euclid's axiom that can't be proven. But the theory of relativity is based on this axiom, which is that the speed of light is absolute. Therefore, at a speed close to the speed of light, there is no reference frame at all, and the reference frame is the case of the macroscopic low speed of the object, and the theory of relativity can degenerate into Newtonian mechanics, and then there is a reference frame.

Do you think it's child's play? What he himself could not prove as an axiom? Actually, this is nothing, it can be said that all modern science is based on the axiom system, you can agree with the Euclidean axiom that a line segment can be extended indefinitely, and there is no reason not to agree with the love axiom of the absolute speed of light.

Maybe one day this axiom will prove wrong, that's fine, but for now it's still useful

As already mentioned in senior physics, Einstein was initially faced with two choices, either to deny Maxwell's theory of electromagnetism or to deny the existence of a frame of reference, and Einstein chose the latter. This is one of Einstein's two fundamental assumptions: that all physical laws are the same in different inertial frames of reference.

The other is that the speed of light in a vacuum is the same in different inertial frames of reference, so it's that person who is moving at the speed of light and not you, and you are not moving at the speed of light. All in all, you shouldn't choose him or you as a frame of reference!

The previous netizens have already said the reason, and I am adding:

2.Uniform motion does not encounter this phenomenon, because if you keep moving at a constant speed, you and your friends will never meet, so you must slow down and accelerate and have a U-turn process;

3.General relativity solves this problem, the stronger the gravitational field, the slower the time, and your friend slows down and turns back to the same process as in a gravitational field, so time passes slowly, so he is younger than you.

Landlord, what the second floor said is right, I'll explain it to you:

In the theory of relativity, time and space are relative, for example: if you say that you have been on the earth for an hour, this has to take a frame of reference, if you choose the earth as the frame of reference, then you have only passed an hour relative to the earth, and there is not an hour relative to the spaceship, maybe 59 minutes.

The theory of relativity assigns the speed of light to the limit speed in the universe, and no object with mass can reach the speed of light, because the mass of an object accelerating to the speed of light is infinite, and the energy required is also infinite.

The speed of time in the theory of relativity is only caused by the difference in the frame of reference, even if you can accelerate you to the speed of light, your time does stop, but you don't feel that your time stops, you don't feel anything else, you feel that you are completely normal.

The third floor also said that "the light you see is the speed of light, but the light itself doesn't think so", and the light will think that you are the speed of light.

The essence lies in the fact that the "relative" landlord still does not understand.

You see light at the speed of light, but light doesn't think so.

The special theory of relativity is to be used in an inertial frame, and the revolution around the earth is not an inertial frame.

Moreover, the so-called 1s is the "apparent" time on the spacecraft, if it moves at high speed, we will see that the clock on it moves very slowly, and the human movement is so slow that it almost stops, and we can only see the clock on the spacecraft go for only 1 second after a year.

So the ship flies fast, but we'll see that everything in the ship evolves slowly, and that's it.

You will see the spaceship speeding past your eyes at close to the speed of light, like a beam of light flying in front of your eyes, because when you look at that ship, it is your time. But as a person on a spaceship, he has his own time, and his time is much slower, as it is said upstairs that "everything in the whole spaceship evolves slowly" but as a person on the ship, they themselves do not feel this "slowness", which is also relative to the observer under the spaceship.

The theory of relativity is a basic theory about space-time and gravity, mainly founded by Albert Einstein, and is divided into special relativity (special relativity) and general relativity (general relativity). The basic assumptions of the theory of relativity are the principle of invariance of the speed of light, the principle of relativity, and the principle of equivalence. The theory of relativity and quantum mechanics are the two fundamental pillars of modern physics.

Classical mechanics, which laid the foundation of classical physics, is not suitable for objects moving at high speed and objects under microscopic conditions. The theory of relativity solves the problem of high-speed motion; Quantum mechanics solves problems under microscopic subatomic conditions. The theory of relativity has greatly changed mankind's "common sense" concept of the universe and nature, and has put forward new concepts such as "simultaneous relativity", "four-dimensional space-time" and "curved space".

Special relativity.

Main article: Special theory of relativity.

Special relativity is a theory of relativity that is limited to discussing the case of inertial frames. Newton's view of space-time saw space as a straight, isotropic, and point-identical three-dimensional space, and that time was a single dimension (and therefore absolute) independent of space. The special theory of relativity holds that space and time are not independent of each other, but are a unified four-dimensional space-time whole, and there is no absolute space and time.

In special relativity, space-time as a whole remains flat, isotropic, and point-isotropic, an ideal condition corresponding to a "global inertial frame". The special theory of relativity takes the speed of light in a vacuum as a constant as the basic assumption, and the Lorentz transform can be deduced by combining the principle of special relativity and the properties of space-time mentioned above.

General relativity.

Main article: General theory of relativity.

The general theory of relativity is a theory published by Albert Einstein in 1915. Albert Einstein proposed the "equivalence principle", which states that gravitational and inertial forces are equivalent. This principle is based on the equivalence of gravitational mass with inertial mass (so far experiments have confirmed that the difference between gravitational and inertial mass is still not seen in the range of accuracy of 10 12).

According to the principle of equivalence, Einstein generalized the principle of special relativity to the principle of general relativity, that is, the form of the laws of physics is invariant in all frames of reference. The equation of motion of the object is the geodesic equation in that frame of reference. The geodesic equation has nothing to do with the inherent properties of the object itself, but only depends on the local geometric properties of space-time.

Gravity is the manifestation of the geometric properties of space-time. The existence of material mass will cause the bending of space-time, in which the object still moves along the shortest distance (i.e., along the geodesic line - in Euclidean space, it is a linear motion), such as the earth's geodesic motion in the curved space-time caused by the sun, which is actually revolving around the sun, causing a gravitational effect. Just as on a curved surface of the earth, if it moves in a straight line, it actually walks around the great circle of the earth's surface.

The vernacular means that when you walk, you're moving relative to the ground, and vice versa.

It's the equivalent of one person being in the toilet and the other being waiting outside the toilet.

The special relativity theory of moving ruler is shortened, and the moving clock is delayed; I don't know in a broad sense.