Why is the speed of light regarded as the universal speed limit?

According to Einstein's theory of special relativity, the speed of light is the universal speed limit. This means that nothing can travel faster than the speed of light in a vacuum, which is approximately 299,792,458 meters per second. The speed of light is regarded as the universal speed limit because it is the maximum speed at which information or matter can travel in the universe.

One of the key principles of special relativity is that the laws of physics are the same for all observers who are moving at a constant speed relative to each other. This is known as the principle of relativity. Another principle is that the speed of light is always constant, no matter how fast an observer is moving. This is known as the principle of the constancy of the speed of light. Together, these principles imply that nothing can travel faster than the speed of light.

The implications of the universal speed limit are profound. For example, as an object approaches the speed of light, its mass increases and its length contracts. This is known as time dilation and length contraction. At the speed of light, an object would have infinite mass and zero length, making it impossible to accelerate further.