Can anyone explain to me the special theory of relativity

The special theory of relativity is a theory of space-time created by Einstein on the basis of the work of Lorentz and Poincaré, etc., which is an extension and modification of Newton's view of space. Einstein started from the principle of the invariance of the speed of light and established a new view of time and space. Further, Minkowski provides a rigorous mathematical basis for the special theory of relativity, thus incorporating the theory into the geometry of a four-dimensional space with Minkowski metrics.

Basic arguments. Albert Einstein published the foundational nature of the special theory of relativity, "On the Electrodynamics of Moving Bodies". On the rationale of the special theory of relativity, he wrote:

The following considerations are based on the principle of relativity and the principle of invariance of the speed of light, which we specify as follows:

1 The law by which the states of a physical system change have nothing to do with which of the two coordinate systems in which the state changes are described is the one of the two coordinate systems that move at a uniform speed with each other.

Special relativity.

2 Any ray of light moves at a definite velocity c in a "stationary" coordinate system, regardless of whether the ray is emitted by a stationary or moving object. ”

The first of these is the principle of relativity, and the second is the invariance of the speed of light (artificially assumed). The whole theory of special relativity is based on these two basic principles.

Explanation of the principle. Matter moves eternally in interaction, there is no matter that does not move, and there is no motion without matter, because matter moves in interconnectedness and interaction, therefore, motion must be described in the interrelationship of matter, and it is impossible to describe motion in isolation. That is, the motion must have a reference, i.e. it must be described in a certain frame of reference.

Special relativity.

Galileo Galilei once pointed out that the motion of a moving ship is indistinguishable from that of a stationary ship, that is, when you are in a closed cabin, completely isolated from the outside world, then even if you have the most developed mind and the most advanced instruments, you will not be able to perceive whether your ship is moving at a uniform speed or stationary. It is even more impossible to perceive the magnitude of the speed, because there is no reference. For example, the overall state of motion of the entire universe is not known, because the universe is closed.

Einstein quoted it as the first fundamental principle of special relativity: the principle of special relativity. Its content is:

Inertial frames are completely equivalent and indistinguishable from each other.

The famous Maxelson-Morey experiment completely repudiated the aetheric theory of light and came to the conclusion that light has nothing to do with the frame of reference. In other words, whether you are standing on the ground or on a speeding train, the measured speed of light is the same. This is the second fundamental principle of special relativity, the principle of invariance of the speed of light.

From these two basic principles, all the contents of the special theory of relativity, such as the coordinate transformation and velocity transformation, can be directly derived. For example, the velocity transformation, because of this unique property of light, was chosen as the only ruler of four-dimensional space-time. See.

At the beginning of the development of physics, people did not recognize the speed of light, thinking that the speed of light is infinite, that is, the "simultaneity" seen in any two places is absolute.

But with the development of physics, people have discovered that light has speed, which brings problems, and "simultaneity" is questioned.

For example, how can two clocks be accurately calibrated? When one clock is at 0 o'clock, it takes time to convey this information to another clock, and to accurately calibrate the clock, it is necessary to know the speed of light in order to know the time required for the exchange of information between the two clocks.

Under the concept of absolute space-time, people think that it is enough to measure the speed of light relative to our frame of reference, but the problem arises. It was found that the measured speed of light does not change either with the velocity of the luminaire or with the velocity of the light receiver.

This is completely inconsistent with the theory of velocity superposition, but it is again a measurement fact.

When the theory contradicts the facts, it can only be assumed that there is something wrong with the theory.

Thus the edifice of classical physics crumbled under this fact, and the physics community was in an uproar.

Einstein summarized the theories and experiments of his predecessors, discarded the concept of absolute space-time, accepted the fact that the speed of light does not change in the experimental results, and founded relativistic physics on this basis.

Special relativity.

Theoretically, the conversion relationship between the time and scale observed by the inertial frames is determined. It re-establishes the correctness of classical physics in low velocities and small spaces. Through the introduction of the Lorentz factor, the classical physics theory is extended to the application of high-speed and large-space fields.

Let's take a simple example to illustrate the significance of this conversion:

Suppose a person is moving at the speed of light (no one doubted that it can reach the speed of light before the advent of relativistic physics), see what happens.

Let's say the distance is 1,000 kilometers (this length is arbitrary), you time him at the end of the line, start the time when he passes the starting point, and stop when he reaches the end point.

However, when he reached the end through the information of the beginning, he also reached the end. The results of the timing showed that he ran 0 distance in 0 seconds.

Because he moves at the speed of light: when he is seen at the beginning, he is at the end, and the distance is 0. Time is 0.

What if it wasn't the speed of light? Obviously, the closer you get to the speed of light, the slower time becomes, and the shorter the distance.

We made assumptions earlier, and if there were no prior assumptions, what we saw was a phenomenon that no one would tell you how far he had traveled at the speed of light. This is what has been observed, and there is no way to verify whether this fact is true or not, because there is no faster speed than the speed of light to test the speed of light. Nor does it occur to anyone to verify whether a thing seen is true.

The Lorentz transform is derived from the fact that the speed of light is finite but unchanging.

This conversion factor solves the conversion relationship between time and scale observed at relatively high speeds. Observation errors caused by the finite speed of light are eliminated.

1. The special theory of relativity predicts some new effects (relativistic effects) that Newton's classical physics does not have, such as time dilation, length contraction, transverse Doppler effect, mass-velocity relationship, mass-energy relationship, etc.

2. Special relativity has become one of the foundations of modern physical theory: all microscopic physical theories (such as elementary particle theory) and macroscopic gravitational theories (such as general relativity) meet the requirements of special relativity. These relativistic kinetic theories have been confirmed by many high-precision experiments.

3. Special relativity includes not only a series of inferences such as time dilation, but also Maxwell's Hertzian equation transformation. Special relativity requires the use of mathematical tools that introduce tensors. Special relativity is an extension of Newton's theory of space-time, and to understand special relativity, it is necessary to understand four-dimensional space-time, which is mathematically formed as Minkowski geometric space.

<>1. The special theory of relativity states that the faster a person moves, the slower the person's time, and when an object moves at the speed of light, then his time is stationary. To give a layman's example: when you see an object, you can't see it because it glows, but if you move it away from the object at the speed of light, you won't see it.

If an object is emitting a beam of light, then the light emitted before the second will never be seen, that is, the second will never pass, so time stops. If it is less than the speed of the light and dust, then the same reason, the time will be shortened. It's like seeing a train coming, if it moves in the same direction as the speed of the train, the train won't overtake everyone.

2. Special relativity is relatively difficult to understand, and it can be explained by comparing objects with the speed of light.

1. What you are talking about is actually the "twin paradox".

It depends on your athletic status.

If you exercise with A, it seems to you that B slows down, i.e. B only walks a little bit.

If you don't exercise like B, you feel that A slows down, i.e. it seems to you that when A walks in one lap, B walks more than one lap.

If your movement is different from A and B, it depends on how well you are moving relative to them.

You don't need to stay with A and B, as long as the movement state is the same (or different)) 2, it depends on the fact that you are in ** when they happen.

You say "observation", so the phenomenon observed in different locations is different.

1.The theory of relativity is like this, depending on which coordinate system you are in, if you are with A, you will feel that B is walking slowly, if you are with B, you will feel that A is walking slowly, if you are also moving, you see that A and B are moving at high speed, then you will feel that A and B are moving slowly.

It happens first, and then B happens because you go through A first, and it takes time for B's events to reach you.

1. The moving clock slows down, the time of b, t= 1-(u c) 2*t', the time of t'a, and u is the velocity of b.

2. To determine whether an event occurs at the same time, it is necessary to see whether it is at the same time and in the same place, which is also calculated according to the Lorentz transform.