Strained Glass - Physics Demonstrations - Strained Glass | Physics Undergraduate Labs

Overhead projectors can become hot during extended use. Avoid leaving plastic materials on the stage for prolonged periods as they may warp or deform, potentially affecting the stress patterns or damaging the sample.

Purpose

Strained glass placed between crossed polarizers on an overhead projector reveals internal stress patterns as colorful birefringence fringes. Students observe how mechanical stress creates optical anisotropy and how rotating the analyzer changes the visible interference colors.

Safety Warnings

Warning: Projector Heat

Purpose