Let's make slime!

Cornflour slime doesn’t act like a normal fluid. When you apply a force to slime, it behaves differently to what you might expect if you applied the same force to a regular fluid like water. Try and stir your slime quickly. Even punch your slime! What happens?

Slime is a non-newtonian, or stir-thickening fluid. The harder your stir it, the thicker it gets. When you look at cornflour through a powerful microscope, it consists of lots of jagged pieces with rough surfaces. When you apply a quick force to slime, all of the tiny jagged pieces of cornflour get jammed together, preventing water from flowing through your mixture, and the slime acts like a solid. But if you slowly apply a force from slime, water can flow more readily between the cornflour, and the slime acts like a liquid.

Our Scienceworks challenge to you

Test the properties of some other fluids you might be able to find at your house! Some fluids, like honey, are thicker, or more viscous than other fluids such as water. But there are also non-newtonian, stir-thinning fluids, such as tomato sauce and toothpaste, and these fluids become runnier when you apply a force to them! If you hold a bottle of tomato sauce upside-down, does it quickly flow out? What happens if you apply a force and hit the bottom of the bottle?