I’ve wondered similar. Light can be bent by gravity and can’t ‘escape’ a black hole. So the speed of light is proportional to gravity and is not a pure constant (right?). We also know speed impacts time. If there was a ‘big bang’ does ‘space time’ change as matter accelerates? Does ‘space time’ change as the acceleration slows? Or stops? Or decelerates? Therefore, time is not a constant either (right?).
If time is ‘relative’ then using constants to estimate the age of anything is only accurate in the ‘short term’ - whatever that actually means.
I love science, work in a technical field - but am no physicist. This has bothered me for a while though and I’ve not seen a discussion surrounding these concepts. Maybe it’s because I’m completely ignorant to why the discussion has no merit.
General relativity says that spacetime itself is bent by gravity* and light just "follows the bend".
*Actually, I think it would say that spacetime is bent by massive objects and gravity is one of the results of that bending.
and can’t ‘escape’ a black hole. So the speed of light is proportional to gravity and is not a pure constant (right?).
Nope. The speed of light through a vacuum is a constant. (The speed of light through a non-vacuum medium can be much lower; that's how lenses work for example.)