Maybe you've wondered what sound waves look like?
The video below shows you sound's geometric vibration patterns, called Chladni patterns, named for "Father of Acoustics" Ernst Chladni (1756-1827). Chladni published one of the first treatises on the science of sound. (A musician, he invented both the euphonium and the clavicylinder; a meterorite enthusiast, he was among the first to claim, correctly, that meteorites originated in outer space and, subject to earth's gravity, fell from the sky.)
Note: You might want or need to adjust the video's sound.
(My thanks to Open Culture, where I first saw this visualization.)
Chladni Plates: First Step Towards Visualizing Sound at Whipple Collections