6C10.20 - Diffraction - Fingers and Squinting | Instructional Resources and Lecture Demonstrations

See paragraph one in the procedure section.

Code Number:

6C10.20

Demo Title:

Diffraction - Fingers and Squinting

Condition:

Good

Principle:

Diffraction of Waves

Area of Study:

Optics, Astronomy

Disclaimer

Equipment:

A distant or pinpoint light source, your fingers.

Procedure:

Look at a distant light source through a gap in your fingers that are just far enough apart to see through. You should see a diffraction pattern that changes as you increase or decrease your finger gap.

References:

Robert Ehrlich, "Q.9, Squinting at an Unfrosted Bulb", Turning the World Inside Out, p. 201.
Borislaw Bilash II, David Maiullo, "Two-Finger Diffraction", A Demo a Day: A Year of Physics Demonstrations, p. 350.

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