What operator acting on the vacuum state (vacuum state of the box?) gives a m^3 box of cosmic background radiation at 2.7K? As the temperature 2.7K slowly drops (wait a million years) must our operator above change in time? Do photons scatter via gravitions so that their energy changes (very slowly) in time ? We have a box of photons that over time has fewer and fewer photons (?) and their average energy over time decreases (?). Does energy change in jumps or continuously? Something is going on in my box? Thanks for your help!