You can never say 'never' but all measurements have led us to believe that c is a universal constant at this stage in the development of the Universe. There is a lot of evidence for this in the spectrum of light that we receive from millions of light years away. Exactly the same structure is observed in the spectrum of the light that's received and that strongly implies that the quantum mechanics at work out there is exactly the same as the QM we use here. If c were different, you would expect everything else to look very different and it doesn't.LogicobraElphfaVolf said:
The current accepted value for the speed of light in a vacuum is approximately 299,792,458 meters per second.
The speed of light was first measured by Danish astronomer Ole Rømer in 1676 using observations of the moons of Jupiter.
If the speed of light were not constant, it would have a significant impact on our understanding of the fundamental laws of physics, such as the theory of relativity. It could also potentially affect the behavior of light and electromagnetic radiation, leading to changes in the behavior of matter and energy.
So far, all evidence points to the speed of light being constant. The theory of relativity, which is supported by numerous experiments and observations, is based on the assumption of a constant speed of light. Additionally, the speed of light has been measured to be the same in all directions, indicating that it is indeed a constant value.
The speed of light plays a crucial role in many technologies that we use daily, such as telecommunications, GPS, and satellite communication. It also allows us to observe and study distant objects in space, giving us a better understanding of the universe. Additionally, the constant speed of light is essential for the functioning of the laws of physics that govern our world.