Knowledge about the relativity chord dimension

Documentary] Dimension: A Math Walk.

Learn how the universe works.

Walk through the wormhole with Morgan Freeman.

Time Machine. Einstein Trilogy.

Step into Stephen Hawking's cosmic world.

Looking up at the night sky: Big**.

Book] Does God Roll Dice - A History of Quantum Physics

From One to Infinity

Adventures in the Physical World

Magical Two-Dimensional Nation

The encyclopedia should be enough for you, and, I agree with the guy downstairs, I've also seen those documentaries, it's excellent, I hope it can help you.

To buy books, if you want to learn advanced ones, you must have a deep mathematical foundation, and popular science is not for those who are interested. It is recommended to buy Tongji's advanced mathematics for self-study first, and then buy some physics books. It's hard but it's fun.

A Brief History of the Theory of Relativity.

RelativityThe theory of relativity is the essence of physics.

Albert Einstein and the theory of relativity.

。。。How do you answer this?

Find it for yourself, competition books, college physics books and the like.

The real answer is also a copy, and I'm not interested in this work.

In fact, the theory of relativity destroys the idea of absolute time, but it also establishes the existence of absolute velocity. This absolute speed is the speed of light. The reference for the speed of any object should not be absolute rest, but the speed of light.

Einstein's theory of relativity simply means that everything in the world is relatively static and in relative motion. For example, if I sit on a stool, I am relatively stationary with the stool and the surrounding objects, while I am in relative motion with the moon (or the sun, a car moving outside the window, or a pedestrian) (i.e., the distance and relative position between each other change).

As the saying goes, "time is like an arrow", time and our lives pass at a speed of 300,000 kilometers and seconds, if you travel at the speed of light, the result is as if you are driving a high-speed car to catch up with the train, the train is compared to "time" (or time) You are at the same speed as the train, then your relative position (or motion) with the train is stationary, that is to say, you are relatively still with time, then your life (or time) does not pass, so your age stays at this moment. Back on Earth, life on Earth is still passing at a speed of 300,000 kilometers per second, and of course the difference between the speed of rotation and the speed of light is a problem that seems outrageous.

The relative counterpart is absolute (not antonym). The theory of relativity means that there is an absolutism relative to it, and it is the classical theory of mechanics. In classical mechanics, time and space are absolutely constant, and in relativity, both time and space are relatively variable.

In this way, things will appear that we can't imagine. These things have yet to be confirmed.

The core of the theory of relativity is:

Time is different for different observers.

So that there is no contradiction.

For example, two people stand together, A moves and B does not move, relatively, you can say that B moves and A does not move Or the simplest, you sit on the train, the train you make is stopped, but the train next to you is moving, and you will also have the illusion that the other car is stationary, and the car you are sitting on is moving

After the light surpasses the speed of light, in fact, I don't think it is possible to reverse time, at most, he catches up with the light that spreads, simply put, a beam of light from the sun to the earth, I remember that it is definitely not a second to arrive, the current optical imaging technology is to accept the light emitted by the sun from the stage, so we can only see the sun dozens of seconds ago, in fact, we can only do this degree of time reversal, the speed is fast, and we can only catch up with the rays of the sun that used to be, we can only observe, But it's absolutely impossible to be in it.

Simply put, the closer the speed is to the speed of light, the slower time passes.

If you move faster than the speed of light, you can turn back time.

Answer: 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.

Special Theory of Relativity: Newtonian Mechanics, Electrodynamics, Calculus, Matrices.

General Relativity: Differential Geometry.

Relativity. The theory of relativity is a theory about the relationship between the motion of matter and time and space. It is one of the theoretical foundations of modern physics.

The theory of relativity was established and developed by Albert Einstein and others at the beginning of this century on the basis of summarizing experimental facts (such as the Michael Murray experiment). Previously, the classical view of space-time (epithetically represented by the Galilean transformation) had led to a series of sharp contradictions. In view of these problems, the theory of relativity has established a new law of space-time and motion of high-speed objects in physics, which has played a significant role in the development of physics in the future.

The theory of relativity is divided into two parts: the special theory of relativity and the general theory of relativity.

The basic principles of the special theory of relativity, established in 1905: (1) In any inertial frame of reference, the laws of nature are the same, which is called the principle of relativity. (2) In any inertial frame, the vacuum speed of light c is the same, i.e., the principle of invariance of the speed of light.

It follows that when the quantities of time and space are transformed from one inertial frame to another, the Lorentz transform should be satisfied, not the Galilean transform. This leads to a number of important conclusions, such as the fact that the sequence of the two events or whether they are "simultaneous" appears to be different in different frames of reference (but the law of cause and effect still holds).

When measuring the length of an object, the length of the moving object in the direction of its motion is measured to be shorter than when it is at rest. Similarly, when measuring the time process, you will see that the moving clock is progressing more slowly than the stationary clock. The mass m of the object increases with the increase of velocity v, and its relation is that m0 is the mass at rest, which is called the mass at rest.

The velocity of any object cannot exceed the speed of light c. The mass-energy relation between the mass m and the energy e of the object satisfies the equation e=mc2. The above conclusions are consistent with the current experimental facts, but the effect is only significant when moving at high speeds.

In general, relativistic effects are so small that classical mechanics can be considered an approximation of relativistic mechanics at low speeds.

In 1916, the general theory of relativity was established, and its basic principles were: (1) the principle of general relativity, that is, the laws of nature can be expressed in the same mathematical form in any frame of reference. (2) The principle of equivalence, that is, the gravitational force in a small volume range and the inertial force in a certain acceleration system are equivalent to each other.

According to the above principle, the gravitational force arises due to the existence and certain distribution of matter, which makes the properties of time and space uneven (the so-called space-time curvature); and thus established the theory of gravitational field; Special relativity, on the other hand, is a special case of general relativity when the gravitational field is weak. Some important conclusions can be derived from the general theory of relativity, such as the precession law of Mercury's perihelion; Light rays bend in the gravitational field; In a stronger gravitational field, the clock is slower (or the spectral lines in the gravitational field move towards the red end), etc. These conclusions are generally consistent with subsequent observations.

In recent years, the conclusions of general relativity have been confirmed with higher precision by measuring the delay in the time of the back-and-forth propagation of radar waves in the sun's gravitational field. The theory of relativity is of great historical significance, but many issues still need to be studied.