This video explores some of the non-Newtonian behaviors of oobleck when shaken. The pattern across the surface once the vibrations start is called Faraday waves, a type of nonlinear standing wave that forms once a critical vibrational frequency is passed and the flat surface of the fluid becomes unstable. Toward the end of the video, the frequency of the vibrations is increased until “finger-like protrusions” form. This is a behavior exhibited by shear-thickening non-Newtonian fluids.
Using non-Newtonian fluids as “liquid armor” is an active area of research and development. Here students demonstrate the efficacy of shear-thickening as a defense against sudden impact by dropping a bag of oobleck containing a raw egg from different heights.
Non-Newtonian fluids are a favorite for displaying odd behaviors. High-speed video simply improves the experience.
Remember, though, that non-Newtonian fluids don’t actually become solids when you hit them. They just react similarly to a solid because they exhibit a nonlinear response to deformation.
What happens when you fill a pool with a non-Newtonian fluid? Well, for one, you can hold races across the surface! In this video, the pool is filled with a mixture of cornstarch and water, a shear-thickening fluid known as oobleck.
