At such (magnitude) of distances, our notion of miles (and kilometers) has no kinda breaks down ...

For example , inside a black hole - time stops - because light can't travel at all due to gravity .. for all practical purposes (if there is one :-) the black hole, thus, has infinite distance ( universal scale) with in it .. quite possible we are inside a black hole - information is encrypted on the event horizon in n-1 dimension ..

Btw - in radiative zone , light doesn't slow down , it is that a photon is consumed by tightly packed nucli as soon as it walks (at the speed of light) for one mm ...