I'd long wondered what would happen if you superimposed two lasers, say, offset so that they would cancel each other out over their whole trajectory. It seemed

I'd long wondered what would happen if you superimposed two lasers, say, offset so that they would cancel each other out over their whole trajectory. It seemed like a violation of conservation of energy, but if "paired photons" like this are considered to still exist despite being "cancelled out" it makes more sense. Which raises an interesting question- are paired photons a candidate for dark matter? The paper might discuss this, but from an I'm-at-work-and-also-a-layman glance I can't make much of the sections on the vacuum and inertia.