Somewhere in my internet surfing at work one day, I found an article about oobleck--a substance that is neither liquid nor solid, and something that Dr. Seuss turned into a character in one of his books. With Dr. Seuss in mind and a childish obsession with science projects I decided to try my hand at making oobleck!
Oobleck two parts cornstarch to one part water, which forms this pancake batter-smelling, silly putty-meets-glue-feeling concoction. Being that it's neither liquid nor solid, you can pick up pieces of it and roll it into a ball, but it subsequently oozes out into a liquid once you stop applying pressure to it. If it drops onto a hard surface, it will ooze, but you can pick up the ooze as a solid. When you try to throw it, it turns into a liqud.
I don't understand why no one let me play with this stuff as a kid!!! It's totally not harmful, wouldn't hurt a kid if they accidentally consumed it, it cleans up like a dream (just add water and it's not oobleck anymore!), and is SO MUCH FUN. Mark and I played with the oobleck for way longer than was probably appropriate for adult members of society, but it was worth it.
P.S. I filmed this video with one hand and played with oobleck in the other, so it's not the best representation, but you'll get the gist. Now go make it for yourself and play!
And, for those who are REALLY interested in oobleck, you should check out these videos where people walk on oobleck and where oobleck dances on a speaker.