If you’re looking for a fun science-inspired Halloween experiment with the kids, try making Oobleck together! Never heard of Oobleck before? You’re not alone! The first time I heard about it was when I was in engineering school. Oobleck is a non-Newtonian fluid; it has properties of both liquids and solids. If Silly Putty and Slime had a child together, you would end up with Oobleck. You can slowly dip your hand into it like a liquid, but if you squeeze the oobleck or punch it, it will feel solid. It has to do with the non-linear relationship of shear force and the viscosity of the fluid. Did that make sense? The name oobleck comes from the Dr. Seuss book, “Bartholomew and the Oobleck.”
It’s super easy to make. All you need is cornstarch, water, and a little shampoo if you want it to smell good and food coloring if you want to make it a certain color.
- Start the food coloring into the water in a bowl or tub and add the cornstarch a bit at a time.
- Keep stirring until it has a gooey consistency. You’ll want to use your hands.
- Tap your hands and slowly sink yours hands in to feel the difference in consistency when applying different pressures at different speeds. Or if you’ve made a larger quantity in a tub, jump on it and walk slowly on it to feel the difference.