A gentle, long period wave is barely disturbed, and just raises and lowers the water level at the piling. However, a wave about the size of the piling is scattered sideways. In this way dust takes the white light from the sun and reorganizes it by wavelength. The background color of the sky comes from scattered light, and is blue, while the image of the sun comes from direct light, and is yellow-red. If the number of scatters is very large, the sun will appear blood red.
Milk is slowly mixed into the water.
As the milk is added, the circle of light on the wall will turn red, and the tank of water, blue. This is a little bit confusing, in that glasses usually appear to be quite rigid just like any other solid material. In fact, almost all glasses can quite accurately be described as being a liquid which has been cooled so far below its melting point that it is extremely viscous and thus has the mechanical properties of a solid. In a crystal every atom is precisely arranged. Each atom is a certain distance from its neighbors, and the bonds between atoms always have the same angles with other bonds.