3B50.40 Moire Pattern Transparancies

PURPOSE: To help illustrate the extended interference pattern from two point sources

DESCRIPTION: Two overhead transparancies, each printed with a circular pattern, are placed atop each other on an overhead projector. As the center of the patterns are shifted, the interference maxima and minima are clearly shown on the screen.

SETUP TIME: Minimal

COMPONENT LIST:

    


  1.   Overhead Projector


  2.   Moire Transparancies

SUGGESTIONS: This is particularly helpful for reminding students that interference patterns (especially the interference of coherent light) are not formed solely at screens, but rather are continuous patterns that propagate through space.

REFERENCES: PIRA 3B50.40

OTHER NOTES: