This week we have a new sensory mixture, Oobleck, in our classroom. What is Oobleck? Well, it is a simple mixture of water and cornstarch. Is it solid? Is it a liquid? It actually behaves as both!
Other familiar substances, like water, change states from solid to liquids to gasses by changing temperature. But Oobleck is a pressure dependent mixture. Oobleck changes states from a solid to a liquid by changing the pressure placed upon it. Applying pressure on the mixture of Oobleck increases its viscosity (thickness). A quick tap on the surface of Oobleck will feel hard and wet. The pressure from a finger pushes the cornstarch particles together. But, if you slowly slide your finger into the mixture, through the water, the corn starch particles have time to move out of the way, creating a smooth liquidy path. This pressure (created through a child’s hands playing) physically changes the Oobleck from a solid to a liquid.
Back and forth, fingers and hands poke, drag, squeeze and drip. It can be soothing to some children, almost meditative, who want to spend all of playtime with their hands moving around, exploring the different states of this mysterious mixture. Sensory play stimulates learning through exploration, curiosity, problem solving and creativity. Nerve connections in the brain are built through sensory play and language and motor skills are strengthened
For others, it can seem a bit disconcerting. Is it slimy? Will it get on my clothes? Will it come off of my hands easily? And while teachers don’t ever insist that a child play with Oobleck, we do try and model how wonderful it can be. And we offer tools like spoons and glue paddles, for those who really don’t want to get their hands into it.
Feel free to make some Oobleck at home. Just mix equal parts water and cornstarch in a container that allows enough room for a child to move their hands around freely.