Chladni Figures - Bowed

Purpose

To show two-dimensional standing waves in a metal plate.

Equipment

Plates with holding clamp, bow and sea sand.

Suggestions

Practice bowing technique.

Images

Description

Sand is sprinkled onto a circular or square thin metal plate, which is then stroked along the edge using a violin bow. The salt moves to nodal lines of the standing wave pattern. Stroking at one point while holding your finger at another point to forces a node at that point, if desired, creating a variety of standing wave patterns.

References

Robert H. Johns, Bow for Vibrating Plates, TPT 12, 500-501, (1974). A. T. Jones, Sound (van Nostrand, New York) 172-180, (1937).