He is askng for an explanation in terms of quantum mechanics and I gave one, but I prefer the first explanation I gave in term of the speed of light. What is nice about tired light or steady-state universes is that the two explanations are consistent. The big-bang universe is full of inconsistencies and paradoxes which are somehow not paradoxical if you do the math and don't think too hard about the heuristics. In short, it is a mess that can only be sorted out if you think outside of the box which defines it.