Cornstarch And Water

10113
cornstarch and water

Cornstarch And Water

Next up is a fascinating substance that is also very easy to make–all you need is cornstarch and water. Get ready to amaze your little ones with Oobleck!

What You Will Need

– 1 cup water
– 2 cups cornstarch
– food coloring
– cookie sheet
– speaker or subwoofer

What You Will Do

Mix the cornstarch and water in a mixing bowl. That’s it, you’ve just made Oobleck.

Now, place the Oobleck on the cookie sheet and rest it on the speaker. You’ll want to drive it with a 55 KHz subwoofer test tone or some bass-heavy music.

You may have to jiggle the Oobleck to get it going or vary the volume.

Check out this video to see it in action.

What is Going On?

Is it a liquid or is it a solid? The answer is both, or neither. It’s actually a non-Newtonian fluid. Confused? That’s ok.

We’re used to seeing materials change properties or phases when we vary their temperatures. We cool water to make it ice and heat it to turn it into steam. Water is a Newtonian fluid, as is air. We won’t get into the exact definition of Newtonian fluids if you’re interested, Wikipedia link can surely help you out. Oobleck is a type of material known as a dilatant or shear thickening fluid. The viscosity increases with pressure.

So, if you move your fingers through the oobleck slowly, it will feel like a liquid. If you hit it quickly with some force, it will react like a solid.

Extra credit- fill your kids’ swimming pool with oobleck. You can walk/run across the surface easily. Stop, and you’ll sink. Awesome!

Want a kit that makes this even easier? Get it here:

Comments

SHARE
Previous articleFood Coloring Experiment
Next articleHoop Glider
Oliver Gauss

Oliver has a degree in physics and mathematics and has completed all but his dissertation for a Ph.D. in Physics. He believes actual science should decide scientific disagreements, and that most people who use “science” to defend their emotion-based opinions have no idea what science actually is.

Oliver is the editor of WeWantScience.com and has two new sites coming out soon. Stay tuned!