Incredible Speed Of Light Constant Over Time 2023. As mentioned, the speed of light is the fastest speed in the universe, and it is always a constant in a vacuum. As the universe has expanded in volume light has slowed down, perhaps going so far as back to the big bang when it was infinitely fast and there was no time because everything happened at once etc.
In particular i am not really convinced that the measured speed of light is the same in every reference frame. Einstein established this within his. To measure the speed of light in one direction, you'd need a synchronized stopwatch.
