Interference animations
A two-dimensional, circular wave, depicted by gray scale.
Addition of waves is by direct superposition. For two identical waves, the
result is simply a doubling of the amplitudes at all times and places.
Offset waves interfere, resulting in alternating nodes (directions in which the
waves cancel completely) and antinodes (directions in which the waves
add constructively).
The pattern of nodes depends on the wave spacing: more nodes for wider
spacing.