The principle of the invariance of the speed of light in one direction, the principle of the invaria

Theory of RelativityFrom a theoretical point of view, the "principle of invariance of the speed of light" refers to the fact that the speed of light is constant in one direction, and the speed of a beam of light transmitted in one direction is c no matter which inertial frame it is in. Or, to put it another way, two separate beams of light emitted from the same light source transmit "in one direction", regardless of the movement of the light source, and the two beams of light should have the same velocity measured in either inertia. The one-way direction here is the light that is always transmitted in the same direction according to the literal meaning, or more precisely, the light that is not refracted or reflected, and "travels freely", you can compare it to the "particles moving in a straight line at uniform speed" in Newtonian mechanics. The theory of relativity never says "the principle that the average speed of light does not change".

As for why this concept exists, we can start with the Michelson-Morey experiment. In this experiment, a beam of light is divided into two beams using a beamsplitter (so that they have different directions relative to the rotation of the earth), so that the two beams of light are reflected and return to their original positions, forming interference fringes. If the speed of light of these two beams of light is different, a certain shift in the interference fringes can be expected.

Since this shift was not observed, it is generally believed that this verifies that the two beams of light, which are propagating in different directions relative to the Earth's motion, have the same velocity.

However, due to the use of reflection in this experiment, there are incident light and reflected light in the optical path, and according to the existing experimental results, it can be explained if it is assumed that the speed of light after the incident and reflection average of the two beams in the propagation process is equal. In the same way, other similar experiments, because the path of the beam propagation must always be changed (because we can only use interference in our experiments, and interference requires the coherence of the light source, so that the two beams of light used for the experiment must come from the same place, and they must interfere, so they must converge in the same place, so that it is impossible to use two beams of light transmitted in one direction, and they must change the direction of their propagation in the process), therefore, some people will argue that these experiments can only prove that the speed of light does not change on average, so they propose the so-called " The average speed of light does not change".

However, this has nothing to do with whether the theory of relativity is correct or not. For example, there are no experiments that have proved Newton's first law (where do you go to find an object that is completely free from force?). But we still use Newtonian mechanics at low speeds.

It is true that we have not experimentally "proved" that the "one-way" speed of light is constant, but we have enough experiments to support the relativity inference that this is a hypothesis, and there is no empirical proof that the pseudo-one-way speed of light is constant.

Light is directional, and you know that.

Light is composed of light particles, and the movement of this particle has a direction. The average speed of light is supposed to be obtained when viewed from the side of the light particle's motion. The unidirectional speed of light is measured by observation from the front of, or behind, the direction of the light particle's movement.

The result designation of the withdrawal is different for the two.

To be honest,I didn't understand what the landlord wanted to ask.。。。 Hey

The principle of the invariance of the speed of light is as follows:

The speed of light in a vacuum is the same for any observer. The principle of invariance of the speed of light, in the special theory of relativity, refers to the fact that the propagation speed of light in a vacuum is a constant regardless of the inertial frame (inertial frame of reference) in which it is observed, and does not change with the relative motion of the light source and the frame of reference in which the observer is located. This value is 299,792,458 meter seconds.

Basic Definitions:

There are two basic principles of special relativity, namely the principle of relativity and the principle of invariance of the speed of light. The principle of invariance of the speed of light: In any inertial frame, the velocity of light in a vacuum is equal. This assumption is called the principle of invariance of the speed of light.

Basic Explanation:

The principle of invariance of the speed of light is one of the two basic assumptions of special relativity, in which it means that the propagation speed of light in a vacuum is a constant relative to the observer, regardless of the inertial frame of reference in which it is observed, and does not change with the relative motion of the light source and the observer's frame of reference. This value is 299,792,458 meter seconds.

Confirmed information:

Fold one of the basic starting points:

The principle of invariance of the speed of light was obtained by solving Maxwell's equations simultaneously and confirmed by the Michelson-Morey experiment. The principle of invariance of the speed of light is one of the basic starting points for Einstein's creation of the special theory of relativity.

The speed of light in a folded vacuum:

In general relativity, since the so-called inertial frame of reference no longer exists, Einstein introduced the principle of general relativity, the principle that the speed of light does not change in the form of the laws of physics: the speed of light in a vacuum is the same for any observer.

System Information:

The principle of invariance of the speed of light: the propagation speed of light in a vacuum is a constant, regardless of the inertial frame (inertial frame of reference) in which it is observed. Four facts that prove that the speed of light does not change.

1) Stellar light aberration.

2) Stars are all small dots one by one.

3) Stars are stationary.

4) The Michelson-Morey experiment of sunlight. The fact that the optical travel difference of any stellar remains constant for a long time proves that the light travel difference does not change with time, so the speed of light does not change with time. The difference in light travel for all stars is angular distance, proving that all stars have the same speed of light.

Analysis: If there is a beam of light in the k system propagating with velocity c in a certain direction (here you might as well take the x-axis direction), i.e., v = c, then the Lorentz velocity transformation formula is used. The propagation velocity of this beam in k is v = i.e., the speed of light in a vacuum observed in other inertial frames is also c in accordance with the principle of invariance of the speed of light.