Bill Otto, former principal engineer, Lasers and Electro-optics at Boeing, explains more precisely: “In actual white objects, light is actually refracting (and reflecting) through extremely large numbers of small prisms or droplets of dielectric materials. Good examples are (1) a cloud of water droplets (2) a bowl of sugar crystals (3) a layer of snow. [Look carefully, and all that is there in a ‘white’ material is a lot of clear transparent refracting surfaces.] Most of the light is refracted around randomly, and eventually some of it, after several refractions and reflections, comes back in your direction. The same is true in a glass of milk, in white paint, and in white paper.”
For more of Bill’s explanation and diagrams, see
I do not send any questionnaires with boxes for skin color before I take on a new student. If a student works with me and we like each other, a good relationship will begin.