Forgive my naive question - I am not a scientist. Why does radiation radiate? Particle a sits there giving off radiation - ok but why? Why does the radiation move away from the source instead of simply sitting there or indeed radiating inward as opposed to out? I ask this because we see this effect and accept it but cannot yet describe the mechanism for Gravity - can it not just be the opposite and equal reaction to radiation from mass and directed inward? Forgive me if this isa stupid question.