Please wait for the animation to completely load.

Two sources of light waves of equal frequency and amplitude are shown. The magnitude of the electric field is represented by the light and dark areas. The lighter the spot, the greater the magnitude of the electric field at that spot (position is given in nanometers). Restart.

1. What wave pattern would result if the phase of the bottom source was increased by 180°? Explain.
2. How would the pattern be different if, instead, the top source was changed?

The applet calculates seven frames and then runs continuously. For a large number of sources, or for very small wavelengths, this calculation can take some time so let the applet finish calculating all seven frames.