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An Oobleck Recipe and Fun Experiments With a Non-Newtonian Fluid

Linda Crampton has an honors degree in biology. She has taught high school biology, chemistry, and science as well as middle school science.

What Is Oobleck?

Oobleck is a strange and very entertaining liquid. It becomes a solid when pressed, hit, or shaken and then returns to its liquid state when the stress is removed. Playing with oobleck is great fun for both children and adults. It's quick, easy, and safe to make and contains only two ingredients: cornstarch and water. I've found that students in the youngest grade of high school right through to the oldest grade love making oobleck and exploring its behaviour.

Experimenting with oobleck is not only enjoyable but also illustrates some interesting science facts. The only disadvantage is that experimenting with the material can create a mess, but even this problem can be solved (or perhaps reduced) with some careful foresight and preparation.

Corn, or maize, is a nutritious grain. It's also a source of cornstarch, which is helpful for both cooks and oobleck makers.

Corn, or maize, is a nutritious grain. It's also a source of cornstarch, which is helpful for both cooks and oobleck makers.

Green Goo in a Doctor Seuss Story

Oobleck is named after the sticky green substance in the 1949 Doctor Seuss book Bartholomew and the Oobleck. In the book, King Derwen is bored with the weather in the Kingdom of Didd and wants to see something new fall from the sky. He asks his magicians to create a magical spell to solve the problem. The spell causes green oobleck to fall on the kingdom.

The goo creates multiple problems. It traps people and animals and clogs spaces. The king wants the magicians to stop the oobleck falling from the sky, but the cave where they live is covered by the goo. Bartholomew is a page boy in the kingdom. He suggests that the king says "I'm sorry" for his foolish request. Once the king does this, the oobleck disappears.

How to Make Oobleck

Ingredients

1 cup of water
1 1/2 to 2 cups of cornstarch or corn starch (which is called cornflour or corn flour in the UK)

(Any ratio of about 1 part water to 1.5 to 2 parts cornstarch will work.)

Instructions

  • Add the water to a bowl.
  • Children may like to rub some cornstarch between their fingers before they add it to the water. The starch has an interesting, silky feel.
  • Gradually add the cornstarch to the water and mix with a spoon (or your hand).
  • Once you’ve added 1 cup of cornstarch, add some more slowly and start mixing with your hand so that you can feel when the oobleck is ready.
  • Squeeze the oobleck as you add the cornstarch. If it forms a solid ball as you squeeze and then liquifies when you stop squeezing, it's ready to use.
  • If you make a mistake during mixing, add extra water or cornstarch until the oobleck forms.

Some people like to add food colouring to the oobleck for fun, but don't add too much because it can stain skin and clothing. Add a small amount of the colouring to the water before you mix the water with the cornstarch. A green colour would be fun for children who like the Doctor Seuss book. Making green goo could also be a way to introduce children to the book.

Experiments for Children

You might want children to wear an apron during these potentially messy experiments. You might also want to think carefully about where the experiments should be performed and to cover the surface that is being used. In my experience, oobleck can spread widely when used by enthusiastic students.

  • Squeeze some oobleck to make a solid, then open your hand and watch the solid turn back into a liquid.
  • Roll some oobleck into a ball. Open the hand that is holding the ball and watch the solid change into a liquid.
  • Create an oobleck ball and try to pass the ball to someone else before it liquifies. (This is potentially a very messy activity.)
  • Try bouncing an oobleck ball on the rest of the oobleck.
  • Measure how long it takes for strands of liquified goo to drip into a container from a specific height.
  • Rest your fingers on the surface of the oobleck and let them sink, then try to pull your fingers out quickly.
  • Find out how fast you can move your fingers through the goo.
  • Try using a hand or fist to slap or hit some oobleck. A large aluminum tray is good for this experiment.
  • Fill a large container (or two smaller containers) with oobleck. Try walking on the goo. You will have to move your feet rapidly to avoid sinking.
Oobleck is safe, since it can be made with only cornstarch and water. The food colouring added to oobleck may stain clothes, however.

Oobleck is safe, since it can be made with only cornstarch and water. The food colouring added to oobleck may stain clothes, however.

The Creeping or Dancing Oobleck Experiment

Creating creeping oobleck is one of the most interesting experiments with cornstarch goo. The goo seems to have a mind of its own during this activity. To perform the experiment, a speaker that produces sounds that are łoud enough to vibrate the speaker is needed. One with strong base sounds is best. Once a suitable speaker is obtained, the rest of the process is easy.

  • Place the speaker on its side.
  • Cover the speaker cone with strong plastic wrap (such as that used to make a garbage bag) or with a double layer of the wrap. Make sure that the edges of the wrap are securely attached to the speaker box with strong tape.
  • Plug in the speaker.
  • Place a light-weight metal tray containing oobleck on top of the plastic and the speaker cone. Some people place the material directly on the plastic to get a stronger effect. Don't use a large amount of oobleck in case its weight breaks the plastic.
  • Turn the speaker and the source of the music or sounds on and enjoy the strange result.
  • Don’t use an expensive speaker for this process in case the plastic breaks. Watching YouTube videos of the process may be safer for equipment than performing the experiment in real life. Many people find that the plastic protects the speaker, but there's no guarantee that this will be the case.
  • Once the experiment is over, turn off the speaker and unplug it with dry hands.

The oobleck forms strange, changing tendrils as it solidifies and then liquifies in response to the vibrations coming from the speaker. Watching the tendrils can be fascinating. Two of my senior students demonstrated creeping oobleck during a project on non-Newtonian fluids. They used an iPod touch to drive the speaker.

How to Dispose of Oobleck

Never pour oobleck or cornstarch down the drain. The drain may block if liquid oobleck solidifies inside it. Instead, pour or scrape the oobleck into a garbage can. The dried material becomes a powder and is easy to brush away.

Wash your containers and hands (and any other body parts or clothing covered with oobleck) only when most of the material has been removed and put in the garbage container. Warm water will help to remove oobleck remnants from hands.

What Are Newtonian Fluids?

Most fluids are classified as “Newtonian” fluids. They’re named after Isaac Newton, the famous scientist who lived from 1643 to 1726. He made many extremely valuable contributions to our present knowledge of science. Newton stated that fluids have a constant viscosity (ability to flow) if the temperature is kept constant. Applying a force or stress to the fluid doesn’t change its viscosity.

An example of a Newtonian fluid is water. If you press your hand on water in a container, the water doesn’t resist the force that you’re creating or change its viscosity and your hand falls into the water. It you try to walk on the water, you sink.

What Are Non-Newtonian Fluids?

Non-Newtonian fluids behave differently from Newtonian ones when a force or stress is applied to them. If you press, hit, or shake a non-Newtonian fluid, its viscosity changes. In some fluids the viscosity increases while in others it decreases. In oobleck, the viscosity increases with stress as the oobleck resists the applied force and the liquid becomes a solid.

Four Types of Non-Newtonian Fluids

TypeDescriptionExampleAction

Shear Thickening or Dilatant

Viscosity increases as stress increases

Oobleck

Squeezing or hitting oobleck causes it to solidify.

Shear Thinning or Pseudoplastic

Viscosity decreases as stress increases

Tomato sauce or ketchup

Shaking a bottle of thick ketchup causes the ketchup to become more liquid.

Thixotropic

Viscosity decreases as a stress is applied over time

Honey

Continually stirring solid honey causes it to liquify.

Rheopectic

Viscosity increases as a stress is applied over time.

Cream

Continually whipping cream causes it to become thicker.

This is a typical oobleck mess. Don't let the mess discourage you from making oobleck, though. The process is great fun.

This is a typical oobleck mess. Don't let the mess discourage you from making oobleck, though. The process is great fun.

Why Does Oobleck Solidify Under Stress?

Oobleck is a colloid, which is a mixture consisting of large but still microscopic particles suspended in another substance. Cornstarch particles are spread through the water in liquid oobleck but aren't dissolved in it. The starch particles exist as long chains.

When the oobleck is not under pressure, the cornstarch chains and water molecules slide past each other and the oobleck is a liquid. When pressure is applied, the cornstarch molecules are pushed together and water molecules are pushed out of the way. Friction increases as the cornstarch molecules come into contact. The starch molecules can no longer slide over one another and the oobleck appears to be a solid. When the pressure is removed, water moves in between the starch molecules again and the oobleck returns to its liquid form.

It should be noted that some scientists believe that there are additional processes at work in oobleck solidification. It may not be a simple process. Researchers at Georgetown University think that the study of oobleck's behaviour could be useful in the creation of soft robots and a new type of body armour.

Walking on Oobleck or Custard

Traditional custard is a mixture of egg yolks and milk which is heated until it thickens. While I was growing up, however, “custard” meant Bird’s Custard to me. This is sold as a powder containing cornstarch mixed with artificial flavour and colour.

If custard powder is mixed with water in the right proportion, oobleck forms. If you had enough of the custard oobleck you could put it in a pool, as shown in the video below. Then you could walk on custard, as the demonstration shows.

An Educational and Fun Activity

Don't let the potential messiness of playing with oobleck discourage you from performing the activity. It can certainly be a very messy activity, especially when performed by enthusiastic children (or even by eager adults). It's wonderful to have a fun and safe experiment for youngsters that can also teach them about the science of fluids, though. With some guidance from a parent or teacher, playing with oobleck can be not only fun but also educational.

References

© 2011 Linda Crampton

Comments

Linda Crampton (author) from British Columbia, Canada on July 21, 2020:

You're welcome, Lois.

Lois Wist on July 21, 2020:

Thank you so much!!!

Linda Crampton (author) from British Columbia, Canada on July 20, 2020:

Hi, Lois. Thank you for asking for permission to use the material. The videos were obtained from YouTube. The creators have enabled online sharing, so it should be fine for you to use the videos, as long as you don’t claim ownership of them. The text is copyrighted to me, however. The science facts in the article can be used, but the wording is mine and mustn’t be copied. Good luck with your course.

Lois Wist on July 20, 2020:

May I use the overview and the videos of this article to create an online lesson plan for my students? I have a Physics degree and wish use this information to enlighten my students on Non-Newtonian Fluid. This is for a private online non-credentialed education course not public or private school.

Linda Crampton (author) from British Columbia, Canada on February 16, 2015:

Thank you very much, WASSUP!

WASSUP on February 16, 2015:

AWESOME

Linda Crampton (author) from British Columbia, Canada on September 19, 2012:

Hi ICarrie. Yes, with three kids in the home oobleck experiments could be very interesting! As long as you're prepared for the mess though, playing with oobleck will probably be fun for everybody. Thanks for the visit and the comment.

Carrie Jones from Georgia on September 19, 2012:

Awesome!!! I almost forgot about that book. I read it as a child until the cover came off and a few more times after that. I am excited to make this experiment and family time activity. We are going to have to read the book and play with our very own ooblek. Hope it doesn't take over the whole house. With three kids you never know.

Linda Crampton (author) from British Columbia, Canada on September 11, 2012:

Hi, unknown spy. Yes, oobleck is amazing, and great fun to play with! Thanks for the comment.

Life Under Construction from Neverland on September 11, 2012:

woowww that was amazing!!! this is really fun to try

Linda Crampton (author) from British Columbia, Canada on July 14, 2012:

Hi, ptosis. Thanks for commenting. Yes, making and playing with oobleck is fun for adults as well as children!

ptosis from Arizona on July 14, 2012:

I had no idea it was so easy to make - I thought it was high dollar/high tech stuff. Fun to do on a rainy day and make a kid wonder. (parents also!)

Linda Crampton (author) from British Columbia, Canada on October 07, 2011:

Hi, CMHypno. Thanks for commenting. The oobleck experiment is fun, and it can be educational, too. The cornstarch goo is very popular with children!

CMHypno from Other Side of the Sun on October 07, 2011:

Never heard of oobleck before, but it looks like a fun experiment to try out. Thanks for the great tips Alicia

Linda Crampton (author) from British Columbia, Canada on October 06, 2011:

Thank you for the visit and the comment, Tina. Yes, exploring the properties of oobleck is very enjoyable for children!

Christina Lornemark from Sweden on October 06, 2011:

This was total news to me, I have never heard nor seen it before! This was so fun to read and learn about Oobleck and it must be a great activity to do with children! Thanks for this interesting and useful hub!

Tina

Linda Crampton (author) from British Columbia, Canada on October 04, 2011:

Hi, Prasetio. Thank you once again for the vote! Oobleck experiments are a lot of fun to perform.

prasetio30 from malang-indonesia on October 04, 2011:

Nice experiment. Actually I had never know about this before. I learn much from you. Thanks for share with us. Vote up!

Prasetio

Linda Crampton (author) from British Columbia, Canada on October 03, 2011:

Thanks for the visit and the votes, Chatkath. I think that "oobleck" is a lovely word! It also sounds strange, which suits the nature of the cornstarch and water mixture very well.

Kathy from California on October 03, 2011:

Most entertaining hub Alicia! Oobleck! My vocabulary just grew, as I have never heard of it, making your hub that much more fun! I have got to try this one! Voted up, useful and interesting!

Linda Crampton (author) from British Columbia, Canada on October 03, 2011:

Hi, Movie Master. Thanks a lot for commenting and for the vote. Playing with oobleck is fun, and it's interesting to observe its behavior, too!

Movie Master from United Kingdom on October 03, 2011:

Hi Alicia, what a fun hub to read and I am so excited about making Oobleck, now I know exactly what I will be doing next week with my grandaughter!

Voting up and thanks for sharing.

Linda Crampton (author) from British Columbia, Canada on October 02, 2011:

Thank you, snizinspiredbyGod. It is fun to play with oobleck.

The experiment with the speaker is my favorite one - I find it fascinating to watch the oobleck tendrils!

snizinspiredbyGod on October 02, 2011:

Where were you when I was in science class? Enjoyed. Can't wait to try it!!!

Linda Crampton (author) from British Columbia, Canada on October 02, 2011:

Hi, Becky! Making and experimenting with oobleck would be a great homeschooling activity. The only precaution that needs to be taken is to prepare for the mess that will probably be created! Thanks for commenting.

Linda Crampton (author) from British Columbia, Canada on October 02, 2011:

Thank you very much, b. Malin. I appreciate your comment! I enjoy writing all my hubs, but I must admit that creating this one was especially fun. Oobleck is a wonderful substance because it's safe and easy to make and playing with it can be enjoyable for people of any age!

Becky Katz from Hereford, AZ on October 02, 2011:

I homeschool my daughter. I can see an oobleck class coming up. Looks fun.

b. Malin on October 02, 2011:

How much Fun was this Hub to read Alicia...Wow, who knew? Oobleck...So Useful, and so Interesting...It's all so Magical. I will Bookmark to show friends and family. Thanks for sharing!

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