Fickle Steps - stationary waves on the Duddon

This is Fickle Steps up the Duddon Valley past Seathwaite. We liked the steel hawser to guide you across. I found that it was possible to oscillate it at different frequencies to create stationary wave patterns. Firstly, slow vibrations gave the basic skipping rope pattern - that's the fundamental frequency. Gently vibrating it at twice the frequency - it proved easier to judge than I thought - produced the first overtone which has a fixed point called a node in the middle. That's shown in the bottom picture. I did get the third overtone but judging the frequencies is hard. It works because the initial vibration reflects from the fixing at the far side. The incident and reflected oscillations interfere to produce the fixed pattern.