Polarized Plastic Stress Colors

Bright rainbow stress patterns appear. Ask students to predict what will happen. View clear plastic between crossed polarizers. Key idea: Stress changes how polarized light travels through the plastic. Ask: Why can clear plastic suddenly show colors? Safety and cleanup: Handle polarizers gently. https://www.google.com/search?q=%22Polarized+Plastic+Stress+Colors%22+science+demonstration+experiment