Why r both the photon & electromagnetic wave models accepted as a single theory & y was it hard to accept?

Answer 1

It is because of something called wave-particle duality of light. It basically says that light can exist as either a particle or a wave, and has properties of both, but not at the same time. And so, light is a particle, the photon, as well as a wave, the electromagnetic wave. This is so hard to accept because it completely goes against all our intuition and our classical definitions of particles nad waves, but then again, that is what quantum mechanics does. It doesn't make any sense at all, with what quantum entanglement or the double-slit experiment, but when it comes down to the actual mathematical equations and phenomena it starts to make sense.