Explain that this is almost always the case, even if the surface is very smooth. Go over these carefully on the board, and make a large chart to refer to. The amounts of each color is called the spectrum of the light. The strongest color in the Sun's light corresponds roughly to yellow. This is right in the middle of the visible spectrum - the colors we can see.
Refraction Now place the straight stick partially into the jar of water.
Point out how, when one looks from above, the stick appears to be bent by the water. This is demonstrated in the diagram above. Black Body Spectrum Discuss the observation that when an electric stove is really hot, the coils give off reddish visible light. That is, all bodies at the same temperature emit the same spectrum. For really hot objects, like the stove, the hotter the object, the more towards the violet end of the visible spectrum it will appear, as opposed to redder end.