Wellen auf dem Wasser

Push the handle of the pump and watch the forming waves and the surface of the sandy bottom. The wave denotes the rotational motion of water particles triggered by the wind or earth tremors. They have a peak called the crest. The lowest place, the trough, is found between two crests. The length of the wave is given by the distance between two crests and the height of the wave is the height difference between the crest and the trough. The shape of the wave considerably changes when the wave approaches the shore. As soon as the wave meets another from a different direction the waves interfere. They add up, sometimes becoming stronger while elsewhere they can cancel each other out. The result of wave interference is either constructive or destructive interference.