Oobleck is a classic science activity that’s sure to please both children and adults. This amazing substance seems to defy logic as it moves from solid to liquid and back again. If you have never played with Oobleck you are in for a wonderfully, fascinating (and messy) surprise. Never fear, clean-up is fast and easy and requires only a wet towel. Roll up your sleeves and let’s explore the science of Oobleck!
Oobleck was first described in the fantastic book by Dr. Seuss, Bartholomew and the Oobleck (1949). The book (the sequel to The 500 Hats of Bartholomew Cubbins), follows the adventures of Bartholomew Cubbins, royal page in the kingdom of Didd, as he attempts to clean up the mess created by King Derwin when the king orders his royal magicians to cause an extremely sticky green substance known as Oobleck to rain from the sky. The story is great. But making Oobleck is absolutely amazing!
Here’s What You Need
- 1 cup Corn Starch
- Large Bowl
- 1/2 cup Water
- Food coloring (optional)
Here’s What You Do
Pour the corn starch into the bowl. If you would like to color your Oobleck, add 5-6 drops of food coloring to your water. I’ve always thought green was a nice color for Oobleck.
Add colored water to your cornstarch and mix.
Now, slowly add the water to the corn starch, and mix with your fingers. You want a mixture that is about 1 part water and 2 parts cornstarch. You may need to add a bit more water if it is too thick or a bit more cornstarch if it is too watery. You’ll know it’s right when the mixture is thick and gooey.
That’s it. Pretty simple, right? Now it is time to play and explore the properties of this really interesting material. Oobleck may look like a liquid but it doesn’t always act like one. You can actually pick it up. Try it. Grab some of your Oobleck and roll in into a ball in your hand. Now, open your hand and watch as the Oobleck runs through your fingers.
You can hold Oobleck like a solid and watch it pour from your hand like a liquid.
As you continue to explore the Oobleck, think about these questions:
- Can you pour Oobleck?
- What happens when you hold it in your hand?
- What happens if you poke it with your finger (quickly or slowly)?
- Is it a solid or a liquid?
- What happens if you smack the top of the Oobleck with your hand?
Clean Up: Oobleck can clog pipes so don’t pour it in the sink! If you have a dumpster or large trash can, dispose of it there. If it gets on the floor or carpet, don’t worry. Once it dries, it vacuums or sweeps up easily. You can also save containers of Oobleck by covering them with plastic wrap and storing them in the refrigerator.
The Science Behind Oobleck
Is Oobleck a solid or a liquid? Maybe it is a solid and a liquid. Impossible. It can’t be both. The truth is that Oobleck is a non-Newtonian fluid. Most of the fluids we know are Newtonian fluids, but non-Newtonian fluids are a weird but interesting group of fluids. When a force (e.g. sqeezing, stirring, slapping) is applied to a non-Newtonian fluid, the viscosity (resistance to flow) of the fluid increases. In simple terms, any force you exert on a non-Newtonian fluid will make the fluid behave more like a solid. The more force you exert, the harder the fluid becomes. Strange but true! Other types of non-Newtonian fluids include quicksand, ketchup, and blood.
Fast Facts about Dr. Seuss
Here are some interesting things you might not know about Dr. Seuss:
- His name was actually Theodore Seuss Geisel. Seuss was his mother’s maiden name. He started using it as a pseudonym in college.
- Dr. Seuss wasn’t a doctor. He added the Dr. to his name later in life as a joke. His father had always wanted him to be a professor.
- Between 1937 and his death in 1991, he published more than 40 books, which have sold half a billion copies between them. His first book, And to Think That I Saw It on Mulberry Street, was rejected by 27 publishers. In response, Dr. Seuss almost decided to burn it.
- One of his most popular books, Green Eggs and Ham, was the result of a bet that he could not write a book using only 50 words.
