written by Wolfgang Christian and Loo Kang Wee

The Wave Machine model simulates the wave machine produced by John Shive at Bell Laboratories and made famous by the PSSC Simple Waves film.  The machine consists of horizontal bars welded to a torsion rod that is perpendicular to the bars.  The simulation allows the user to change the lengths of the bars, thereby simulating the effect of a wave propagating in a non-uniform medium.

The simulation allows various pulse shapes to be sent down the machine by selecting a function for the twist of the first rod or by dragging the first rod.  For example, applying a Gaussian twist produces a Gaussian traveling pulse but the width of this pulse depends on the wave speed.  The far end of the wave machine can be free or clamped and this changes the nature of the reflected wave.


The  Wave Machine model is a supplemental simulation for the article "Standing Waves in a Nonuniform Medium" by Paul Gluck in The Physics Teacher 49(2), 76-77 (2011) and has been approved by the authors and The Physics Teacher editor.  The Wave Machine model was created using the Easy Java Simulations (EJS) modeling tool.  It is distributed as a ready-to-run (compiled) Java archive.  Double clicking the ejs_mech_osc_chains_WaveMachine.jar file will run the program if Java is installed.

• Download ejss_model_WaveMachine.zip - 487kb Compressed File

Published August 19, 2023
Last Modified August 19, 2023

EJS JavaScript spource code for Wave Machine JS model.

• Download ejss_src_WaveMachine.zip - 118kb Compressed File

Last Modified August 19, 2023