Here is a great DIY experiment that you should definitely try at home.
Oobleck, a name based off of Dr. Seuss’s “Bartholomew and the Oobleck”, is just one such example of a Non-Newtonian fluid. Try this DIY out for yourself. All you’ll need is about 1.5 cups of cornstarch and one cup of water.
Most substances and materials that exist can be put into one of the four states of matter: solid, liquid, gas, and plasma. However, there are some mixtures that can’t fall into those categories, or that can be in more than one of them. Non-Newtonian fluids are one such thing. A Newtonian Fluid is a liquid that has an expected viscosity, or flow rate even when under stress such as a change in pressure. A Non-Newtonian fluid has a non-linear change in viscosity when introduced to a stressor, meaning that it will act a bit weird and unexpected.
When left alone, this mixture acts as a liquid. It has a definite size, but takes the shape of it’s container. However, when you apply a sudden force, such as hitting it or squeezing it in your hands, then it’s viscosity greatly increases. It acts as a solid, having a definite size and its own shape.