The polarization of skylight an example for classroom discussion

Polarization is a unique property of electromagnetic radiation (light). It is discussed at all levels of scientific education, from introductory courses in physics to graduate courses in electromagnetism. As with most physical theories, students appreciate a practical example, particularly when it involves natural phenomena. The polarization of skylight and its use by insects for navigation is such an example. In the remainder of the paper, a simple explanation for the cause of this polarization and for its distribution over the sky is presented. In this brief abstract, the equations describing the phenomenon are not included; they are discussed in the presentation