This model illustrates (and animates) the movement of an oscillating surface. For instance, this could represent a drumhead that has been struck. The center four squares in this model are the source of the oscillation, and as they vibrate up and down, the surrounding cells dampen the effect.
Start - acts as a switch to determine when to run the model
Step - the time step to use in this model
Iteration - how long the model has been running
Pulse - the value that will be used for the center square
The center square on the graph should glide up and down, alternately creating a peak and a valley. The lower the time step, the more smoothly (and slowly) the animation will move.