6H30.10: Three Polaroids on the Overhead
Description: A continuation of 6H30.10 (Polaroids on the Overhead), this demonstraion shows what happens when
a third polaroid is placed inbetween the first two. If the first two were oriented so that almost no light was passing through,
and the third was put inbetween at a 45º angle, some light will pass through. This is counter intutive for most students.
- 3 square polarizers
- Overhead projector
- Have the two polarizers on the overhead arranged so that little to no light is passing through.
- Insert a third polarizer in between the two at a 45º angle. Note that it actually makes it lighter.
- Most students have the misconception that even less light would go through.