Why is the speed of light constant?

Because the speed of light is measured by human beings through reference objects, and light is always emitted by the sun, these two are unchanged, so the speed of light will not change.

With the improvement of the sophistication of modern science and technology and equipment, the data of the speed of light is becoming more and more accurate, becoming the most accurate unit of measurement in the human world.

The internationally determined length of 1 meter is defined in 1983 as the length of light transmitted in a vacuum for 1 299792458 seconds.

The constant speed of light in physics means that the speed of light in a vacuum is 299792458 m s, which is kilometers per second. When we don't need to be very precise, we use the narrative of about 300,000 kilometers per second. This constant means that in a vacuum, the observed speed of light by any observer is constant, so the speed of light becomes the standard measure of distance and the most important constant in the universe.

Because the matter that makes up the light is very stable and does not change under any conditions, the concern is very stable.

Chen's Universe Model: Saying that the speed of light is constant, is it considered "covering one's ears and stealing bells"? It is an indisputable fact that light travels at different speeds in different media.

Why the speed of light is constant: Because the speed of light is a constant remorse of the universe, it does not change.

The development of science in the world is an eternal process, and we can now have these high-tech and information age in fact, thanks to the previous scientists for the wireless exploration of the world, such as the famous physical scientist Albert Einstein's "theory of relativity" to explain the speed of light to us The problem of the speed of light, people will ask why the speed of light is constant, why can it be constant and constant?

In fact, the pre-excitation is because the speed of light is a constant setting of the universe, so it will not change. For example, when we sit on a train and see the scenery outside, we feel that we are in motion, but if we compare the train, we ourselves are stationary, this is a relative velocity, but for light, this law does not exist.

In any case, the speed of light is the fastest and stable speed of the entire universe, without any reference, as if an innate attribute meaning is defined, no matter how it is changed, it cannot change its size, which can also be explained by Einstein's "theory of relativity", let's analyze it.

To put it simply, the universe itself is a super-large existence, which is not at all something we can describe in words, there are countless planets and black holes, etc., these are a system, how to load information and transmit, etc., if it can really exceed the speed of light, it can be traversed, which we actually have in modern science fiction movies.

The speed of light is constant in a vacuum, which is a fundamental principle in physics and is elaborated by Einstein's special theory of relativity. There are several reasons and theoretical bases for the constancy of the speed of light in a vacuum:

Experimental observations: Experimental observations of the late 19th and early 20th centuries showed that the speed of light is not affected by the light source or the state of motion of the observer. For example, the Michelson-Morey experiment tried to detect the effect of the Earth's motion in the ether on the speed of light, but the result was negative, i.e., the expected effect was not detected.

Special Theory of RelativityEinstein's special theory of relativity was based on two assumptions: that the laws of physics are the same in all inertial frames of reference, and that the speed of light is constant for all observers in a vacuum, regardless of the relative motion of the light source or the observer.

These hypotheses have led to phenomena such as time dilation and length contraction, which have been experimentally verified.

The electromagnetic nature of light: Light is an electromagnetic wave that is produced by changing electric and magnetic fields. Maxwell's theory of electromagnetism shows that the velocity of an electromagnetic wave in a vacuum is determined by the permissibility and permeability of the vacuum, which are physical constants.

Therefore, the speed of light is determined by these fundamental physical constants.

Consistency in physics: If the speed of light were not constant, many laws and equations of physics would no longer hold. For example, the relationship between energy and momentum will no longer be valid, which will lead to a contradiction in the fundamentals of physics.

It is important to note that the speed of light is constant in a vacuum, but it slows down when light passes through a material medium such as water or glass. This is because light interacts with the atoms and molecules of matter as it travels through matter, causing the light to travel at a reduced rate and trap. However, even in this case, the phase velocity of the light (i.e., the velocity of the wavefront) is still equal to the speed of light in a vacuum.

The speed of light is a constant value, does not change with the speed of the light source, and is consistent in any frame of reference, what can you deduce?

If the speed of light is variable, let's say there is a flashlight and I make it move at the speed of light, with the glowing side facing backwards, and the light it emits should be still in the air. If the speed of light is constant, then even if the flashlight moves at the speed of light, the light it emits will still move at a constant c speed in our opinion.

So what about a person sitting on this flashlight moving together at the speed of light? Because the speed of light is constant, the light he sees should also be a constant value of c, and the light and the person on the side of the road remain relatively stationary, but the light seen by the person on the side of the road is not static, but the speed of c is moving, and the speed of light should be constant. Isn't this time staggered?

What if the flashlight moves faster than the speed of light? Isn't it a contradiction that the person sitting on the flashlight sees the light that is actually moving away from the person on the side of the road, and the person on the side of the road sees the light coming towards him?

If the glowing side of the flashlight moves forward and moves at the speed of light, and I sit on top of the flashlight, I still can't see still light, I still see light at speed C, which should be the same speed of light. And the people on the side of the road saw that I was chasing after the light, this is the theory of relativity, the clock is slow and the ruler is short?

What I don't understand is how the law of the constant speed of light is reversed. How to confirm it? If the speed of light is variable, then we should be able to measure different speeds of light around us, because our earth is autobiographical and orbital, and the entire solar system is moving in four seasons, and our speed is actually very fast, so the light coming from other stars should have different speeds.

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. That's 299,792,458 meters.

The principle of invariance of the speed of light was inspired by the simultaneous solution of Maxwell's equations and confirmed by the Michelson-Morey experiment.

According to the theory of relativity, the principle of conservation of mass energy, mass can convert energy, and velocity is related to energy. If all the mass is converted into energy, then velocity is the limit. This limit is the photon, because the photon has no mass.

Therefore, the transformation of mass and energy is the law of the universe or nature, and the speed of light is the characteristic of the universe or nature.

If there is another different universe, as long as you calculate the conversion of mass into energy and the speed of light, you can understand the different "time" of that universe, and you can also compare the similarities and differences between the universes. Therefore, the Creator defined the universe only by defining the speed of light.

Interestingly, in the Bible Genesis verse 3: God said, Let there be light, and there was light.

When light is close to a massive object, it bends (in fact, the surrounding space-time is bent, and the light walks along the curved space-time, as if the light is also bent). It should be noted here that the so-called "bending" and "straight" are both relative.

Now that we know that the speed of light is constant, that it moves in a straight line along the space-time in which it is located, let's imagine a scenario:

Scenario 1: If there is no gravitational field, light is moving in a straight line, so it takes the shortest time to get from point A to point B. If you think of this light as a spaceship, and you are in it, you will feel that it takes a short time to get from A to B.

Scenario 2: If a sufficiently strong gravitational field is applied to points A and B, space-time will be distorted, and light will move in a straight line along the distorted space-time plane, so the actual distance traveled by light increases, and since the speed of light is constant, the time it takes for light to move from point A to point B becomes longer. If you think of this light as a spaceship, and you're in it, you feel like it's been a long time to get from A to B.

Light moves in a "straight line" in the gravitational field of the universe.

Because the speed of light is independent of the speed of the observer relative to the light source, i.e. the speed of light measured in the inertial frame of rest and motion relative to the light source is the same.

Albert Einstein's special theory of relativity, published in 1905, proposed that the physical principle and the speed of light are the same for any observer moving at a constant speed, regardless of the speed.

If you are in a rocket, you will rush into space with a laser pulse. Observers on Earth will see this pulse move away at the speed of light. But no matter how fast the rocket moves relative to the Earth, say 99% of the speed of light, light still surpasses the rocket at the speed of light.