All properties and events in the physical universe are governed by laws, and those laws hold true at every time and place in the universe.**
I have just googled “the speed of light” and was returned over 2.6 billion results in 0.79 seconds. I am guessing, because I won’t be checking through all the results, that each will state the speed of light to be 299,792,458 metres per second.
At the same time when the laws of the universe come into contact with consciousness, interesting things happen, new energies being generated that we find difficult to articulate and measure, though not impossible. Jesus of Nazerath described himself as the light of the world on at least one occasion and perhaps we can see our lives as being small lights for the world, each bringing something different and, if we were to deny it, but break the fundamental truth about ourselves.
In the end, only we can articulate just what this “light” might be; only we can measure whether it’s offering some light into another person’s darkness. It’s why we’re here.