The discussion becomes particularly interesting as soon as we try to look from the light s perspective. The light assumes to always move at a constant velocity, i.e. the ratio of the spatial distance and the temporal distance are always the same. It is this analogy that allows us to compare possible experimental set-ups with light in moving media to astronomical objects like black holes. Finally, this analogy allows us to think of experiments in a laboratory being models of cosmic events with the mathematical analogy allowing us to draw conclusions about the universe from what we have seen on Earth. More on light in moving media can be read in Ulf Leonhardt's homepage , in my publications or in one of the popular articles that have been written on the topic.
More pictures are available here.