I feel like I understand photons just as poorly as I do consciousness.
This is not an answer, just more questions.
Reincarnation cannot be disproven either, however. This is what makes this tricky. They claim that one does not need faith for Buddhism, but I think we need faith for even science, because we cannot personally prove all the claims around us.
I'm still very confused and a bit frustrated this is preventing me from enjoying the happiness that I usually get from my Monday class. Many of the books I've read have stated it's much more important to want to cultivate compassion for all beings than in believing in reincarnation, so I should likely focus on that instead. Not believing is a non-virtue, but then so is killing anything, even insects, and I don't see myself stopping eating meat, not swatting mosquitos or not putting out ant-traps in my home any time soon.
EDIT: if we continue the light analogy, then at death the consciousness is spit out, say as x-rays, based on the conditions of that past light. If we then assume that a human life can't absorb the x-ray, then it will pass through the human life until it finds something made of "lead" which might be the animal of a body and is absorbed. This would allow for a single consciousness to travel without being so complex as to have a plan as to where it was going but still have the effects of karma guide where it ended up.
I like this model. I'm sure I still don't have it right, but it's a interesting model to think about.