Polarization puzzles for the upper elementary grades

The concept of polarization and its most basic consequence, Malus' Law, is usually not taught in the elementary or middle grades because of conceptual difficulties. We introduce the concept of polarization using sunglasses to understand the consequences of parallel and crossed polarizers. We then expand the concept with four puzzles. The puzzles are cut out of sheets of linear polarizers and are viewed through a (hand held) spinning polarizer. The first puzzle is constructed out of wedge shaped pieces of linear polarizer so that the wheel appears to rotate when viewed through the spinning polarizer. The second puzzle consists of concentric circles that appear to radiate outward. The third and fourth puzzles are four- and twelve piece wedges that are manipulated to produce different symmetric designs. We have tested these activities on fifth and sixth graders, and find that they enjoy the manipulative as well as the problem solving aspects of the puzzles. They are also able to understand that when light is polarized, 'whatever it is that waves' (the electric field) is oriented in one direction. The materials are inexpensive and can be easily made by teachers for classroom learning.