light doesn't move at a fixed rate light moves AT the speed of causality in that frame of time causality appears to have a MAXIMUM limit in this universe in a

light doesn't move at a fixed rate light moves AT the speed of causality in that frame of time causality appears to have a MAXIMUM limit in this universe in an "empty" void but every time you hear a story of how they "slowed down light" what they actually did is make causality more complex in a dense medium, so slower