In gravitational lensing effect, there are two types of time delay; geometric delay, gravitational delay.
gravitational time delay is not caused by "distance", and speed is "distance/time". the distance is not change but time is expansion, so I came to a conclusion that "light of speed is slow down around gravitational body".
I want to ask that 'Principle of Constancy of Light Velocity' is not applied in "general relativity"?
I guess the reason is the main assumption of special relativity(The laws of physics are invariant -that is, identical- in all inertial frames of reference -that is, frames of reference with no acceleration-, wikipedia "special relativity") is only applied in inertial frame.
Am I correct?
If It's correct, I have a one more question. If there is the spaceship which is accelerating to speed of light, Does the light which emitted from the spaceship have different speed of light with '299,792km/s'?
