Please wait for the animation to completely load.

Two sources of light waves that are in phase, of equal frequency, and have the same amplitude are underneath the red rectangle. 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 arbitrary units). Restart. How far apart are the two sources in terms of their wavelength?

This 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.