Question

What are some examples of light as a particle?

Answer 1

Poynting-Robertson and Photoelectric effect

Explanation:

Light behaving as a wave is really simple to see. There's diffraction, interference of light as a wave, such as in the double-slit experiment, etc.

One indicator is that photons have momentum. So, when light bounces off an object, you do impart a very tiny force onto it.

One very interesting observation is that photons from the sun may cause its outer layer to slow down, while not confirmed yet, we do know photons from the sun do collide with dust in space, and cause them to slow down, called the Poynting-Robertson effect.

Another interesting phenomenon is the Photoelectric effect, now explained by the fact that light is a particle, since it can also eject electrons with low intensity, whereas it should not be able to, following classical theory that light is a wave.

There are a lot more phenomena, but these are the most interesting ones I know.