You are awesome! Succinct. Clear. Respectful of we who are unschooled in theoretical physics. I cannot help but think that gravity is more fundamental than light. The force that moves the universe compels it to syntropy, what ancient philosophers called conatus. The tendency of animate and inanimate matter to evolve, seemingly in contradiction to entropy. I think it supports the theory that the universe is not a closed system, but is powered by infinite energy.

I read a recent post on Medium where someone even suggested that gravity might be the consciousness of nature. A bit metaphysical, I suppose, but certainly intriguing in that science doesn't really understand either...yet.

Thank you for your answer!