The pendulum wave machine was invented in 1867 by Ernst Mach, an Australian physicist. He constructed this machine while he worked in Prague University. (Different sources make different claims as to who is the true innovator behind the pendulum wave machine however Mach seems to be the most likely candidate.)
Its initial purpose was to display concepts of physics such as the conservation of momentum but in today's world it serves other uses as well. One of the most interesting being light shows. One website that I found to be quite useful with my own research was created by the light show, Ghent Festival. They also used the concept of pendulums and different lengths with lights attached to create an interesting and entertaining spectacle to include in their own show.(Example included below)