It's a liquid.....it's a solid.....it's Oobleck!!
-Food coloring (optional)
To make oobleck, add 2 cups of cornstarch and 1 cup of water in a bowl. If you want to color your oobleck like we did, add a few drops of food coloring. It will definitely take some effort to mix the water and cornstarch. I would recommend adding the water to your bowl first...and slowly add the cornstarch as you stir.
Oobleck is a non-Newtonian fluid, which basically means that if you push or squeeze it, it will act like a solid object. But when you let it stand still, it will act like a liquid and flow smoothly. So hit it hard and it will feel like you are punching a wall, but put your hand in the mixture gently and it will flow around your hand like water!
Just as a follow up to my earlier post, my girlfriend sent me this hilarious video of oobleck on the Ellen DeGeneres Show.