Step-by-step tutorial
Step 1
Gather your materials!
Step 2
Add two parts cornstarch and one part tonic water in a small container.
Step 3
Mix well. This creates a substance that acts as both a liquid or solid - called a non-newtonian fluid! When you press on it, it should feel hard, but when you let go, it should turn back into a liquid.
Tip
If the consistency is too watery, try adding a little extra cornstarch. If it’s too dry, add a little tonic water.
Step 4
Plug in and turn on your blacklight.
Step 5
Pour the oobleck into your hands and begin playing with it under the blacklight! What happens when you squeeze it?
Learn more
Oobleck is called a non-Newtonian fluid because it can change its viscosity. Viscosity is a property of liquids that says how fast they flow or how much they resist their shape changing — kind of like how thick a fluid is. Isaac Newton wrote a law a long time ago that said a liquid’s viscosity was supposed to be a constant (unless you change its temperature). Because he never tried making oobleck, he didn’t know that a changing viscosity was possible!
You can test out viscosity at home by trying to stir different liquids. If it’s tough to stir, it has a high viscosity. If it’s easy to stir, it has a low viscosity. And if its viscosity changes and it gets harder (or easier) to stir, then you’ve found another non-Newtonian fluid!