The sun emits light waves with a range of frequencies. Some of these frequencies fall within the visible light spectrum and thus are detectable by the human eye. Since sunlight consists of light with the range of visible light frequencies, it appears white. This white light is incident towards Earth and illuminates both our outdoor world and the atmosphere that surrounds our planet.
The interaction of sunlight with matter can result in one of three wave behaviors: absorption, transmission, and reflection. The atmosphere is a gaseous sea that contains a variety of types of particles; the two most common types of matter present in the atmosphere are gaseous nitrogen and oxygen. These particles are most effective in scattering the higher frequency and shorter wavelength portions of the visible light spectrum. This scattering process involves the absorption of a light wave by an atom followed by reemission of a light wave in a variety of directions. The amount of multidirectional scattering that occurs is dependent upon the frequency of the light.
-Why are the skies blue?
-Why are sunsets red?
You could also just enjoy them (but, understanding them is such a conversation starter):
|Photograph of Maui sunset by Becky Henderson|
Thrill your dates/science/physics teacher (and I pray those sets are "mutually exclusive" ) in the fall with the answers at:
Blue Skies and Red Sunsets - The Electromagnetic and Visible Spectra