In this demo the amplitudes of the two interfering waves are added, and the result is shown as a height or depth on a mesh surface. You can clearly see the stationary nature of the nodal lines:

Here is an interactive animation that demonstrates the motion of a surface over which two circular periodic waves interfere. Instructions and information below.

To interact with the micrometer simulation, you can

  • drag the mouse to rotate view
  • use mouse wheel to zoom in /zoom out
  • turn each source on or off using the checkboxes labeled ‘1’ and ‘2’.
  • Make the two sources oscillate in phase or in opposite phase.
  • Move the sources to the middle or to the edge of the surface.
  • Change the distance between the sources, called d.
  • adjust wavelength, frequency and amplitude using slider

Modified from