>>12561382time dilation at speed c is infinite, light doesn't experience time.
inside a black hole, the light cone (which contains all world lines passing through a point that don't exceed the speed of light) gets all squashed up (as in pic related) and eventually becomes so degenerate that all valid world lines are at the edges of the cone (with speed c). you'd expect the time dilation experienced by an observer following said worldlines to be infinite, hence time 'freezing'.
not sure if that's what they're referring to, or if I misunderstand this so take that with a pinch of salt
perhaps they're just referring to the fact that inside a black hole time and the radial coordinate swap roles, so that the center of the black hole is sort of a point in time and time becomes space
freaky shit, but the event horizon prevents us from ever peering inside a black hole to see what that might actually mean
