[The Science of Oobleck: Exploring Non-Newtonian Fluids]-[Oobleck! Make Up Your Mind! (Encore - 8/2/21)]

Wow in the World · B1 · 2021-08-02

📋 Summary

The Fascinating Science of Non-Newtonian Fluids: A Deep Dive into Oobleck

In a recent episode of Wow in the World, hosts Mindy and Guy Raz take a whimsical yet educational approach to explaining the properties of matter, specifically focusing on the mysterious and behavior-defying "non-Newtonian fluid" known as oobleck.

Defining Matter and the "Trickster" Fluid

The episode begins with a humorous attempt at meditation, quickly transitioning into a scientific exploration of matter—solids, liquids, and gases. Mindy introduces the concept of oobleck, a mixture of cornstarch and water, which she describes as a "non-Newtonian fluid." Unlike "Newtonian fluids" such as water, which maintain a constant viscosity regardless of the force applied to them, oobleck behaves as a "scientific trickster." It does not play by the traditional rules of matter, appearing as a liquid one moment and acting like a solid the next.

The Physics of Oobleck: Force and Viscosity

To understand why oobleck changes states, the hosts reference research from engineers at MIT. The key lies in the tiny particles of cornstarch, which are roughly 100 times smaller than a grain of sand. These particles are heavily influenced by temperature and electric charges.

When one moves slowly through the mixture, the electric charges between the cornstarch grains cause them to repel one another, allowing them to slide past each other like a "creamy liquid." However, when sudden, significant force is applied—such as when a person attempts to rollerblade across the surface—the particles are pushed together so rapidly that they cannot repel each other. This contact creates friction, causing the particles to "bunch together" and transform the fluid into a solid. This shift in viscosity, or thickness, based on the force applied, is the hallmark of a non-Newtonian fluid.

Practical Applications and Experiments

The episode features several demonstrations to prove this concept. When Dennis, a character in the show, tries to move quickly through the pool of oobleck, he becomes stuck as the fluid turns solid under his pressure. Conversely, when he is lifted out slowly, the mixture returns to its liquid state.

Beyond the fun of the "Poobleck" pool, the hosts note that researchers are looking into real-world applications for this technology. One intriguing possibility is using non-Newtonian fluids to fill "potholes" in roads. Because the material can remain fluid to fill a space and then harden under the force of passing vehicles, it presents a unique engineering solution to infrastructure problems.

Conclusion

By blending playful narrative with concrete scientific principles, Wow in the World effectively demystifies a complex topic. The episode highlights how the interaction of microscopic particles and physical force can create materials that defy our standard expectations of matter, turning a simple kitchen experiment into a lesson on advanced fluid dynamics.

🎯Key Sentences

I gotta let you know that

It's going to be a November to remember.

But for now, let's get on with the show.

It doesn't matter.

Okay, back it up, boys.

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📝Key Phrases

music to your ears

get on with the show

full of surprises

play by the rules

give me a hand

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📖 Transcript

Grownups, Wondery Plus subscribers can listen to Wow in the World early and ad-free right now.

Join Wondery Plus in the Wondery app or Wondery Kids Plus on Apple Podcasts.

Hey, Wowzer fans, Mindy here.

And before we start the show, I gotta let you know that this November, with a special new episode featuring our friends at Circle Round and Terrestrials on Radiolab for Kids,

And don't miss when Elmo from Sesame Street stops by Wow in the World to make us all belly laugh on November 24th.

Oh, but that's not all, Reg.

Or study on the web version →