04 Oct Oobleck
Thanks to YouTube the unicorn is always coming up with weird things he wants to try. Not that I’m complaining, it’s how you learn but sometimes I just want to curse YouTube haha.
This week it was Oobleck.
Oobleck, named for a gooey substance that fell from the sky in a Dr. Seuss story is a thick solution of cornstarch in water. The first time I heard about it though was in a series I was watching where the professor did it outside in the university courtyard and they were running across it (the first time they did the run his friend fell in as the mixture was quite right hahaha).
What’s fascinating about it is that it’s a “non-Newtonian” fluid that doesn’t respond to outside forces the way you’d expect. So the harder you stir it, the thicker it gets and the more it resists your stirring. Hit it hard enough, say with a hammer, and it instantly hardens enough to shatter. Hold it in your hand and make a fist and it’s hard but release the pressure on it and open your hand and it will pour out as a liquid.
The phenomenon that lets oobleck do what it does is called “shear thickening,” a process that occurs in materials made up of microscopic solid particles suspended in a fluid. Examples include drilling mud used in oil wells and fluid used to couple automobile transmissions to the wheels.
It’s messy and if you add food coloring it WILL stain your hands but it’s a lot of fun and will keep your kid (and maybe even yourself) entertained for hours. 2 parts cornstarch to one part water. Or just mix till you get it right. should be hard if you put pressure and soft if you are calm.