Science for Preschoolers - Oobleck

In honor of the upcoming birthday of Dr. Seuss I decided to make Oobleck with the kids. This substance's funny name comes from a Dr. Seuss book called Bartholomew and the Oobleck. In this book a king is bored with the regular weather and asks for something different to fall from the sky: a green sticky substance that is called Oobleck.

Some scientific facts: all fluids have a property known as viscosity that describes how the fluid flows – commonly thought of as how thick or thin a fluid is. When a fluid’s viscosity is constant (doesn’t change with force) it is referred to as a Newtonian fluid, for example: water and milk.

However, the viscosity of some fluids changes depending on the stress or force applied to it. These fluids are referred to as non-Newtonian fluids.

Oobleck is an example of a non-Newtonian fluid. It is a mixture of cornstarch and water that becomes more viscous when agitated or compressed. Under force Oobleck behaves like a solid, without force it flows like water. This kind of fluid is called a dilatant material or a shear thickening fluid.

Other examples of non-Newtonian fluids include:

Why make Oobleck? Because it's fun!

Pound on it with your fist and it is as solid as a rock...

in contrast - without force it is a liquid mess :)

Best of all - jumping on a pool of Oobleck... endless fun!

The aftermath is a garden filled with 40 lbs of sticky Oobleck, just like in Dr. Seuss's book :)