List Of Has Speed Of Light Always Been Constant 2023. Can light's velocity be constant while the universe expands ? Relativity still holds if the speed of light is anisotropic.
And since both $\epsilon_{0}$ and $\mu_{0}$ are constant, that means that $\frac{1}{\sqrt{\epsilon_{0}\mu_{0}}}$ is also a constant. And the constant speed is defined by the medium (which happens to be vaccum i.e., no medium for light). Web einstein's work advanced the principle that the speed of light is constant in a vacuum and that strange thing occurs the nearer to its speed you reach.
