The use of smartphones in the introductory physics laboratory has recently received attention since it provides the possibility to perform a variety of didactic experiments. Smartphones equipped with several built-in sensors, controlled by appropriate software, allow students to explore physical phenomena and carry out various measurements of physical quantities. In this article, after a brief historical introduction about the discovery of light polarization and the development of the polariscope/polarimeter, we describe a low-cost and easily constructed smartphone polarimeter that provides a quantitative way of experimenting with light polarization. In particular, we discuss a didactic activity concerning the use of the smartphone ambient-light sensor to measure the intensity of light coming through two properly oriented polarizing filters, which follows the well-known Malus’s law.
In Icelandic medieval legends, to detect the direction of the Sun on cloudy or foggy days during navigation, Vikings used the sunstone (sólarsteinn), probably the Iceland spar (calcite,...