While trying to explain the duality of light to a young friend I told her it is a mystery of Physics that light is a wave and a particle. How could that be? It has polarized wave properties and it can be bent by gravity like a particle with mass. Think of a wave in the ocean, where the water remains in place and the wave energy moves through the water particles. Then think of a wave in a river where the wave stays in place and the the water particles flow through the wave. One is the movement of wave energy, the other is the movement of water particles through a wave field. It is not a perfect parable but I think it helped.
