Polarized Plastic Stress Colors
Bright rainbow stress patterns appear.
Teaching & key ideas
What you do: View clear plastic between crossed polarizers.
What students see: Bright rainbow stress patterns appear.
Why it works: Stress changes how polarized light travels through the plastic.
Question to ask: Why can clear plastic suddenly show colors?
Lesson flow
Predict → demonstrate → observe → briefly explain → ask: Why can clear plastic suddenly show colors?