The role of color vision in answering the question: why is the sky blue?

Studying electromagnetics is a more gratifying experience when the theory is used to explain easily observed, physical phenomena, such as the blue color of the daytime sky. We show the color that the average observer associates with monochromatic light of a given wavelength. The scattered radiation is greatest at the shorter wavelengths, the blue end of the spectrum, so this is often offered as the reason for the blue sky. However, from these considerations, we could equally well say that the sky is violet. At this point, another factor must enter the argument, and that is the response of the human visual system.