After discovering Bartholomew and the Oobleck, by Dr. Seuss, by sheer random luck at the library last week, and enjoying it on the basis of its story alone for several days, I told Rondel that oobleck was actually something we could make at home. I wasn’t sure if he would want to, but he spent the whole next day (while I was at work) telling my husband how he was going to get to make oobleck with Mommy, so at that point it was going to have to happen!
And happen it did:
Oobleck is, in its simplest form, a mixture of cornstarch and water. We added some food coloring to try to make it green like it is in the Dr. Seuss book, but we obviously should have added more! The proportions of the two ingredients have to be just right (approximately a 1:2 water:cornstarch ratio), but when they are, the mixture stops behaving like a liquid or a solid and becomes a non-Newtonian fluid. In other words, the way it responds is based on the force you apply. Let your hand sink down slowly into the bowl and it feels like water; try to pull your hand back out quickly and the substance instantly hardens around you. (For a good overview of the science, check out this article from Cornell).
I spent a lot of time just playing around with it on my own before I could convince the boys to touch it, but after they got over the initial weirdness of it they didn’t want to stop. Rondel in particular enjoyed the odd sensation of it and kept immersing his hands in and pulling them out again over and over and over. In fact, because our air is so dry, I had to keep adding water to the oobleck so he could keep playing with it as long as his interest held – which ended up being about an hour and a half, and would have been longer if we hadn’t desperately needed to put Limerick down for a nap.
Oobleck is definitely a messy activity. Because of the way it sticks to your skin, it’s not going to stay nicely contained in a mixing bowl! However, since it’s just cornstarch, it does hose off of everything fairly easily (much to my neighbors’ relief… the newly returned snowbirds aren’t used to the kids playing in the common area and were worried about the mess). It will also dry out your skin, so it might be good to have lotion on hand for after the clean-up. This was my first time playing with it as well, although I’ve read about it before, and I highly recommend it (and the book!) for both you and your kids!