The speed of light is 300 thousand kilometers per second, which is really fast, but it doesn't need any power and there is no acceleration process. To put it bluntly, light is the speed of light when it is born, and it must be the speed of light.

Traditional thinking tells us that any object needs an acceleration process when it reaches a certain speed, which is also in line with our daily life cognition and experience. For example, there is a process for a car to go from standstill to 100 kilometers per hour. It stands to reason that light should be like this, but it is not like that. The speed of light propagating in different media does change, but once it returns to a vacuum, the speed will still remain at 300,000 kilometers per second.

Introduction to the speed of light?

The speed of light refers to the propagation speed of light waves or electromagnetic waves in vacuum or medium. The speed of light in a vacuum is the maximum speed at which natural objects can move. It has nothing to do with the observer's speed of motion relative to the light source, that is, the measured speed of light is the same in the inertial system of static and moving light source. The mass of an object is also related to the speed at which it moves.

The mass of an object will increase with the increase of speed. When the speed of an object approaches the speed of light, its mass will tend to infinity, so it is impossible for an object with mass to reach the speed of light. Only photons with zero rest mass always move at the speed of light. When the speed of light is superimposed with any speed, it is still the speed of light. The velocity synthesis does not follow the laws of classical mechanics, but follows the laws of relativistic velocity synthesis.

The above content is referenced from Baidu Encyclopedia-Light Speed