Spark image
Standing waves

A stationary or standing wave is one in which the amplitude varies from place to place along the wave. The diagram shows a stationary wave. Note that there are places where the amplitude is zero and, halfway between, places where the amplitude is a maximum; these are known as nodes (labelled N) and antinodes (labelled A) respectively.

A node is a place of zero amplitude
An antinode is a place of maximum amplitude

Any stationary wave can be formed by the addition of two travelling waves moving in opposite directions.

© Keith Gibbs 2010