As part of our ‘Spooky Science’, our class investigated a mysterious substance. Not quite liquid, not quite solid, but a little of both… this is a non-Newtonian fluid! You can make this substance at home by mixing a 2:1 ratio of cornstarch to water. Once mixed well, this substance can behave like a solid and like a liquid!
We tested this substance in a variety of ways, including: slapping/poking the surface, sinking a spoon into it, rolling it into a ball, and trying to pour it into another container. We learned that when we kept the substance still (ex: holding it in our hands without moving), it often would pour or drip like a liquid. But if the substance was being moved (ex: rolling it between our hands), it would take on a more solid appearance.
Check out the video below to see how this substance behaves when placed on top of a speaker cone:
Some questions to discuss at home:
- Could we use ingredients other than cornstarch and water to create other non-Newtonian substances? Why or why not?
- What if the ratio (2:1 cornstarch to water) was different?
- Are there other substances that are not really a solid or a liquid, but a bit of both?
- What variables or human error might have impacted our tests?