Let's suppose that the speed of light would not be a constant but a function of something. As is quite clear now, universe is expanding exponentially. If the speed of light would actually be a function of this expansion, maybe in terms of cosmological constant... We would never find this out because the measure of distance (definition of meter) is now locked; meaning it is defined in terms of the speed of light! Also, in a way we know that the speed of light may indeed be a function of cosmological constant because very distant targets are escaping us faster than the speed of light? Is it hence indeed so that the speed of light just can't be measured, or defined currently by any independent means?
Asked
Active
Viewed 237 times
1 Answers
5
The speed of light is now fixed due to the current definition of the metre and the second. Ir is now exactly 299,792,458$ms^{-1}$.
See Speed of light at Wikipedia
So, today, if you perform an experiment to measure the speed of light, you are really calibrating your equipment rather measuring the speed of light.
The speed will not change again until we redefine the metre or the second.
badjohn
- 2,095