I had not heard of oobleck until I started teaching in the US. But when I read the Dr Seuss book Bartholomew and the Oobleck with my first grade (Year 2) class, they asked, "Can we make oobleck?" We were exploring materials and their properties as part of our science unit, so this sounded like a good idea.
A little online research by my wonderful assistant Jessica revealed that oobleck (a non-Newtonian fluid, similar to quicksand) can be easily whipped up with just cornflour and water. Adding food colouring for a more dramatic effect is optional (this does stain little fingers, so we decided to leave it out). The final consistency should resemble thick yoghurt.
The children loved getting messy as they created, stirred, mixed and explored this fascinating new material - real hands-on science. It also provoked wonderful questions, as oobleck has the properties of both a solid and a liquid, but is neither. "How can it be runny, but then feel hard when you press down on it?" asked Sam.
His observations were accurate. If a force is applied, oobleck gets thicker. When at rest, it reverts to its fluid state. My pupils were able to roll up tight balls of oobleck in their fists. But as they opened their hands, it dripped through their fingers "like gooey gunk" (which they assured me is the correct term).
Rachel, one of our high-school science teachers, popped her head around the door. "It's a thixotropic mixture," she informed us. Now that is a big word for first grade.
Once we had cleaned up the classroom, we found lots of entertaining YouTube videos showing how you can walk (or sink) in a pool of oobleck, and even make it dance on a stereo speaker.
My pupils enjoyed the whole experience so much that they taught the kindergarteners all about oobleck at our recent school science fair. And I enjoyed it so much that I have since shared this fascinating, fun resource with my former colleagues back in the UK. I hear oobleck is now taking Luton by storm.
Quicksand has the same properties as oobleck. Should you find yourself stuck in quicksand, try gently swimming to the shore very slowly. The slower you move, the less quicksand will resist.
Mary McCarney is a first-grade teacher and grade level leader at Atlanta International School in the US.
Visit YouTube for examples of oobleck experiments.
whitechica2 shares a number of gooey recipes for messy lessons.
Or try Science Museum Learning's video and lesson plan about Newton's nemesis.
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