I'd like to correct a misconception you've said repeatedly in this conversation.
Not all energy levels are quantized. There is no minimum energy of a photon. A photon at some hypothetical minimum would have to gradually lose energy as it travels through expanding spacetime (according to our current models), and thus it will decrease.
It is not at all clear what this apparent violation of conservation of energy is resolved by. It's a glaring flaw in that law which is otherwise very reliable. Photons lose energy as they travel through expanding spacetime, and it is not at all clear where that energy goes.
Kinetic energy isn't quantized, either. An object's speed is not universal. It can only be defined relative to another object. It can take on literally any value based on what it is in relation to.
Distances are not quantized. Directions are not quantized. We'd see crystal artifacts when looking out at space if it were, and we don't.
In short, the only things we can reliably say are almost certainly quantized are certain properties in *bound* systems. An electron in an atom can have only certain values of its kinetic energy, but an electron not bound to an atom can have any energy.
Reply With Quote