Speed of Light Reflection: Einstein's Train & Mirrors

[C4m]

Maybe this is way too primitive. But doesn't most of these variables affect the different end results how far the light travels and how much time it takes accordingly?

-PoV
-Angle
-Distance

This might be a 0.000000000001-ish difference, yet its a difference.

 

[Drakkith]

Maybe this is way too primitive. But doesn't most of these variables affect the different end results how far the light travels and how much time it takes accordingly?

-PoV
-Angle
-Distance

This might be a 0.000000000001-ish difference, yet its a difference.

If you measure the distance the light travels over some time interval, it is ALWAYS c in a vacuum. The only things that change how long it takes to reach some point is the distance to that point and the path the light takes to reach it.

In the context of astrophysical jets, the light is traveling in very nearly a straight line to get to us, so the only other variable left is the actual distance between the jet and ourselves.

 

[Sagittarius A-Star]

And there is no difference if mirrors moves away or not?

No. The speed $c$ is invariant. It this the same in the mirror's rest frame and in each other frame.

Did you ever play billiards?

There is a difference.
As others mentioned, billiard balls have a non-zero invariant mass

$m=\frac{E}{c^2}\sqrt{1-u^2/c^2}$.

Light has $m=0$ and therefore moves at $u=c$.

 

[Vanadium 50]

This might be a 0.000000000001-ish difference, yet its a difference.

I'm not sure how this can be sensibly discussed. It's effectively saying you don't believe relativity and you guess the correct answer is something different. OK, so now what?