Oobleck - solid or liquid?

Описание: Chief Scientist Carl Nelson demonstrates the interesting properties of Oobleck - a mixture of cornstarch and water.

This substance is often called non-Newtonian because its viscosity changes depending on the force applied to it. Mix it gently and it behaves like a fluid. Apply a force and it hardens into a solid.

To mix up some Oobleck grab a box of cornstarch, some water and a mixing bowl. In general, a mixture of about 1.5 cups of cornstarch to 1 cup of water is a good starting point. You will have to tweak these amounts to get the perfect mixture. Keep in mind that the mixing process can get messy so be prepared to clean up.

Pour the cornstarch into a large mixing bowl and slowly add the water. You are shooting for a mixture that feels kind of like honey and tears a bit when you run your hands across the top. You will have to experiment with more or less cornstarch or water until you get the right mixture. If you want to color your Oobleck add some tempera paint. You can use food coloring if that’s all you have on hand. Food coloring tends to stain more than the paint, especially if you have a spill while preparing your Oobleck.

One thing to keep in mind is that Oobleck is a suspension, not a solution. The cornstarch does not dissolve in the water like salt or sugar would. Instead, the tiny starch particles are suspended in the liquid. If you let it sit long enough in a glass, the cornstarch will settle to the bottom leaving a layer of clear water on the top. This is why it is very important to *not* pour Oobleck down the drain. Should the suspension separate in your drain pipes, you will be left with a hard clump of cornstarch that will block the drain. The best way to get rid of you Oobleck is to simply put it in your trash can.