In theory, the limitation of anything to the speed of light arises from the fundamental structure of spacetime as described by Einstein's theory of special relativity. According to this theory, the speed of light in a vacuum, denoted by 'c,' is a fundamental constant of nature. Here are a few key reasons why anything, including information and matter, is limited to the speed of light:
Spacetime Geometry: According to special relativity, spacetime is a four-dimensional fabric that combines space and time into a unified framework. The geometry of spacetime is described by mathematical equations, and it is through this geometry that the limitation on speed arises. In this framework, the speed of light acts as a cosmic speed limit because it is the maximum speed at which cause and effect can propagate through spacetime.
Relativistic Effects: As an object with mass approaches the speed of light, its relativistic mass increases, and the energy required to accelerate it further also increases. This relationship between mass, energy, and velocity is described by Einstein's famous equation, E=mc². As an object with mass accelerates towards the speed of light, its relativistic mass becomes infinitely large, and therefore an infinite amount of energy would be needed to reach or exceed the speed of light. This implies that it is impossible for anything with mass to reach or surpass the speed of light.
Cause and Effect: Special relativity also introduces the concept of causality, which states that cause and effect relationships cannot be violated. If information or matter were able to travel faster than light, it could lead to situations where the effect precedes its cause, which would violate the fundamental principles of causality and create paradoxes.
These principles and limitations arising from special relativity have been extensively tested and have shown to be consistent with a wide range of experimental observations. The speed of light acts as a fundamental speed limit within the framework of special relativity, and it is deeply ingrained in our understanding of the structure of spacetime and the behavior of matter and energy.