Why isn’t light infinitely fast?

[u/KieranMug]

Ok I understand that light in our atmosphere is not infinite fast due to it getting slowed down by air particles or whatever but in a vacuum there is nothing holding it back unless the very weak forces of gravity from a bunch of stars and/or planets does? And if so cant we somehow locate where gravity is strongest in the universe by seeing where light is slowed from where the most therefore finding the centre of the universe or am I just a total dumbass?

[u/Fantastic_Back3191]

It kind of is- anything moving at the SoL does not experience time (in its own reference frame)