If you have never heard of Oobleck before, then you are in for a world of fun! Oobleck is described in the dictionary as “a fluid made from cornflower and water that temporarily thickens or solidifies when a force is applied.” However, this description does not do it enough justice because Oobleck is so much more interesting than that. It’s more like something from outer space! So, what exactly is Oobleck, and how do you make it?
Oobleck is a non-Newtonian fluid, a substance or suspension that can mimic the characteristics of a liquid or a solid and can change its viscosity. It’s runny when it is undisturbed and goes solid when it is moved around too fast. It is made by combing water (25%) and cornstarch (75%).
The name “Oobleck” comes from a 1949 book by Dr. Seuss called “Bartholomew And The Oobleck.” It is a story about a mysterious green, slimy substance that falls from the sky, forcing a young boy named Bartholomew Cubbins to save his kingdom. This slime is called “Oobleck!” This article will discuss everything about this exciting goo, including how it’s made.
What Is Oobleck
According to researchers at MIT, “cornstarch particles are so small, they can be influenced by temperature, and by electric charges that build up between particles, causing them to slightly repel against each other.”
Ken Kamrin, an associate professor of mechanical engineering at MIT, says, “As long as you squish slowly, the grains will repel, keeping a layer of fluid between them, and just slide past each other, like a fluid. But if you do anything too fast, you’ll overcome that little repulsion, the particles will touch, there will be friction, and it’ll act as a solid.”
Interesting Fact – Quicksand and ketchup are both examples of non-Newtonian fluids.
How To Make Oobleck
In the experiment below, we will show you how to make your very own Oobleck so that you can test the theory as mentioned before.
There are a few ways to add color to your Oobleck. Some people make their Oobleck by mixing the water and the corn starch first and adding the food coloring afterward, and some mix the food coloring into the water before mixing it into the corn starch.
What You Need
- 1.5-2 Cups of cornstarch
- 1 Cup of water
- Food coloring (any color)
- Mixing bowl
- A spoon or mixing stick
- Newspaper to cover the surface you are working on (this could get messy)
- Prepare your working surface by laying down some newspaper.
- Add a few drops of food coloring (of your choice) to the water and mix well.
- Pour the colored water into a mixing bowl.
- Add the corn starch to the water (bit by bit) and mix it with a spoon or a mixing stick until combined.
- Once you achieve a consistency that goes solid, if you move it around fast and it goes back to a liquid state when you leave it (non-Newtonian), Then you know you are done.
If the substance is too runny (unable to go solid when force is applied), add more corn starch to the mixture.
If the substance seems too dry, add a few drops of water until your spoon glides through the mixture if you move it slowly and crumbles if you move it faster. Its resistance to flow increases when you apply pressure to it
When you lift the spoon, the goo should run down in a dripping, slimy manner.
When you grab a handful, it goes hard, and then it starts oozing out again, unlike any liquid you’ve ever seen, but a liquid non the less. Remember, it is both a solid and a liquid, depending on the circumstances.
Adding the food coloring to the water before mixing it with the corn starch gives you an even color throughout. However, adding the color after you have made your Oobleck is a lot more fun.
It looks so cool as you move the coloring around, and it makes some fascinating patterns you would not have seen if you added the color to the water first. Be sure to give both methods a try.
You can add multiple colors to your Oobleck. Try to create colors by mixing colors such as;
- Blue + yellow = green
- Blue + red = purple
- Yellow + red = orange
Time To Play!
- Grab a handful of Oobleck, squeeze it hard and slowly relax your hand. Watch it ooze through your fingers.
- Drag your finger through it as fast as you can and see how it crumbles.
- Pour it into a balloon (using a funnel), tie it and squeeze the balloon in your hand. Do it softly and hard to feel the different viscosities.
- Leave the Oobleck in a glass jar for a few hours. The liquid and the solids will start to separate since it is a suspension and not a liquid.
- If you have powerful speakers (a sub-woofer works best), place a bowl full of Oobleck on top of it, turn up the volume, and watch it “dance” to the beat. You can see this experiment by checking the video below:
- Make a few batches of Oobleck in different colors. Find a tray to work on, but make sure the sides are high enough to keep the Oobleck from running over the edges. Add blobs of each color onto the tray. You can even place colors on top of each other. Observe how the colors merge and make beautiful patterns.
- Add glow-in-the-dark pigment to your Oobleck and see it come alive in the dark. This works better if you have a black light to bring out the glow.
- Instead of using water, add 1 part dishwashing liquid to 2 parts corn starch to make stretchy Oobleck.
- You can fill up a large container with Oobleck, and if you run over it, you will get to the other side without sinking. Check the video below to see people walking on Oobleck”
How Long Does Oobleck Last?
Unlike dough which can dry out quite quickly, Oobleck can be revived again. If you store it in an air-tight container when you are done playing with it, it can last for days, and best of all, if it gets a little dry, all you need to do is add some more water to it until you have the same consistency that you started with.
The best, most effective way to store your Oobleck to make it last longer is by freezing it. Do not place it in an open mold or container. Instead, put it in a zip lock freezer bag to prevent it from drying out.
When you want to use it again, all you need to do is leave it to defrost, or you could place the bag (sealed)in some warm water to speed up the thawing process. Freezing your Oobleck prevents bacteria and mold from growing on it.
Both of these storage (preservation) methods are effective, but I prefer freezing it to keep it bacteria-free for longer.
I hope this amazing experiment blew your mind! It is fun and educational, making it one of the best science projects for kids to try out.
It teaches them about colors, mixing colors to make new colors, viscosity, ratios, and much more. Be sure to try this with your kids. I guarantee you they will love it, and so will you!