My son is in third grade, and it's time for the science fair. He's interested in doing a project on non-Newtonian fluids (aka Oobleck, from the Dr. Suess book), specifically on the classic cornstarch/water suspension. We've made the stuff plenty of times before, including a kiddie pool full for a birthday party of his about a year ago. My problem is that he needs to come up with a question and hypothesis. I don't want to let him take the easy way out by asking a basic question that he already knows the answer to like "Is Oobleck a liquid or solid?" or "Can you walk on something you can also sink in?" etc.

 

I was hoping someone else might have a good idea for something I can challenge him with. Are there any other surprising things that cornstarch/water might do, where I could let him do this for his science fair but still pose a question he'd have to experiment to answer?

 

Thanks a ton for your time.

I ended up finding that the cornstarch/water suspension is supposed to have some interesting characteristics when heated/cooled, so that's what we're investigating. We took a few other items (like syrup, vegetable oil, and butter) and put a sample of each in the freezer, on the counter, and in a hot pan. He used those as a basis for forming his hypothesis.

Sounds good. I like that you've taken the step beyond simply demonstrating a phenomenon.