3-D Standing Wave Machine

Procedure:

A plain white string is connected to two motors to create beautiful 3D standing waves. Switch the power mode to manual. Move the arms closer together, pivot the heads, tilt the light bar, increase the motor speed, or change the light pattern and flash speed! Red, green, and blue LEDs give you a whole spectrum of color options, or use your own strobe for quantitative observation.

Scientific Principle:

Standing waves are produced by the interference of two waves traveling in opposite directions with the same frequency and amplitude. In a standing wave, the distance between adjacent nodes, or between adjacent antinodes, is equal to one-half wavelength. The number of antinodes determines the harmonic of the standing wave. As the term harmonic may suggest, standing waves are the basis for the sounds produced by many musical instruments. Standing waves are also responsible for the production of light by gas lasers At the heart of the 3-D Standing Wave Machine is a string attached to the shafts of two small, variable speed motors. Each motor sends out a continuous train of waves that travel along the string. These waves interfere to form standing waves.