Sometimes an old viral video needs another airing. In this video from about three years ago, a mixture of corn starch poured into a speaker cone is vibrated at 30 Hz using a signal generator and the video shot at 30 frames per second (coincident timing with the speaker frequency).
Corn starch is a non-Newtonian fluid, which means it does not behave in a “classical” way, it undergoes shear thickening, which means it gets more viscous when a force is applied. You may have noticed it is much easier to stir it slowly than to try and stir it fast.
When the force applied is cyclic, as in the vibrations of the speaker cone, something very odd happens…weird tendrils form and crawl and collapse and regrow.
It’s also worth checking out the ferrofluid sculpture videos that show up when this Youtube clip finishes.