Further informationson the exhibit "Guitar string"
The waves we see on the strings are called "standing waves" because they do not move in one direction. This is different with waves in the sea that move towards the beach, for example. Normally, the guitar strings vibrate so fast that we can't even see these waves. However, the rotating cylinder makes the vibrations of the string visible. Depending on how tightly or loosely a string is tensioned, which can be influenced by pushing the pedal, the wave also varies in size.