Making Oobleck

One of my favorite activities builds on a fantastic book by Theodor Seuss Geisel (also known as 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…that’s amazing!

Here’s What You Need

• Corn Starch
• Water
• Food coloring (optional)
• Bowl

How’s that for a list of materials. It can’t get much simpler than corn starch and water.

Here’s What You Do

In your bowl, slowly add the water to the corn starch (you may want to color the water green…for added effect). Stop when the corn starch/water mixture is thick and gooey. Remember, you’re making Oobleck…not gravy.

That’s it. One step. Pretty simple, huh? As you 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)?
• Can you roll it into a ball?
• Is it a solid or a liquid?

Clean Up: Oobleck will clog sinks 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 putting 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.

Wondershop Fast Fact

Here are some interesting things you might not know about Dr. Seuss:

• His real name was Theodore Seuss Geisel – Seuss being his mother’s maiden name. He started using it as a pseudonym at university. He added the Dr later, as a joke, because his father had always wanted him to get a doctorate and become a professor.
• Between 1937 and 1991, when he died aged 87, he published more than 40 books, which have sold half a billion copies between them – more even than J K Rowling’s Harry Potter books. He nearly burned his first book, And to think that I saw it on Mulberry Street, after it was turned down by 27 publishers.
• 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.

Source: BBC News