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Okay, imagine you have a giant swimming pool filled with what looks like thick, milky water. If you slowly step into the pool, you will sink straight to the bottom just like normal.
But what if you try to sprint across the top of it? What if you jump off the diving board and land directly on the water?
Normally, jumping into water results in a massive splash. But with this weird milky liquid, if you jump onto it, you don’t sink. You don’t even make a splash. Instead, the exact second your feet hit the surface, the liquid instantly turns into a rock-hard solid. You can literally sprint across the surface of the pool without getting your feet wet.
Then, when you stop running and stand still, the ground melts back into a liquid, and you slowly sink.
This is not magic. It is a very real, very weird substance called Oobleck. Let me explain why this liquid completely ignores the laws of physics and decides to fight back when you punch it.
Sir Isaac Newton’s Rule
To understand Oobleck, you have to know about a famous scientist named Sir Isaac Newton. Hundreds of years ago, he wrote a massive rulebook on how liquids are supposed to act.
Newton said that the “thickness” of a liquid (which scientists call viscosity) only changes if you change the temperature. For example, if you want honey to pour faster, you put it in the microwave to make it warm. Temperature is the only thing that matters.
Normal liquids like water, milk, and apple juice follow Newton’s rules perfectly. We call them Newtonian fluids.
But Oobleck? Oobleck does not care about Sir Isaac Newton at all. Oobleck is a Non-Newtonian fluid. Its thickness doesn’t just depend on temperature; its thickness completely changes depending on how much force or pressure you put on it!
If you want to read all the hardcore physics behind fluid dynamics and viscosity, the Institute of Physics (IOP) has some amazing breakdowns of how liquids flow.
The Secret Traffic Jam
So, why does applying pressure make Oobleck turn solid?
Oobleck is actually just a mixture of regular water and tiny, microscopic grains of cornstarch.
Imagine driving your car down a busy highway. If all the cars are driving slowly, everyone can perfectly weave in and out of lanes. Everything flows smoothly. That is what happens when you slowly push your hand into Oobleck. The water acts like a smooth highway, and the cornstarch grains slowly slide past each other.
But what happens if every car on the highway suddenly slams on their brakes at the exact same time? You get a massive, gridlocked traffic jam. Nobody can move.
That is exactly what happens when you punch the Oobleck. By hitting it super fast with a lot of force, you squeeze all the water out from between the cornstarch grains. Without the watery highway, the rough cornstarch pieces violently crash into each other, locking together in a microscopic traffic jam. For a split second, they form a solid brick wall that stops your fist dead in its tracks!
The second you stop pushing, the water flows back between the grains, the traffic jam clears up, and it instantly turns back into a liquid puddle. You can read more about how microscopic particles lock together over at Science Buddies.
Making Your Own Traffic Jam
The craziest part about Oobleck is that it is ridiculously easy and safe to make. You probably have the ingredients in your kitchen cabinet right now.
It gets super messy, so you definitely want a massive Heavy Duty Plastic Mixing Bowl so it doesn’t spill all over your mom’s floor. You can even put your bowl of Oobleck on top of a giant stereo speaker. When you play a really loud, bass-heavy song, the sound waves will act like invisible fists, punching the liquid and making the Oobleck literally stand up and dance in solid, weird shapes!
To read more about how scientists are actually using Non-Newtonian fluids to create flexible, bulletproof armor for the military, bookmark the articles at the National Science Foundation (NSF).
Quick Oobleck Summary
What you need:
– 2 cups of Cornstarch
– 1 cup of Water
– Food coloring (optional)
– A very large plastic mixing bowl
– Your bare hands!
Step-by-step guide:
1. Pour the cornstarch into your large mixing bowl.
2. Add a few drops of food coloring to your water, then slowly pour the water into the cornstarch.
3. Try to mix it with your hands. Notice how if you squeeze it hard, it turns into a solid ball in your palm!
4. Open your hand and watch the solid ball instantly melt back into a liquid and drip through your fingers.
5. Try punching the liquid in the bowl as fast and as hard as you can. It won’t splash; it will feel like punching a wall!
10 Non-Newtonian Brain Teasers
Think your brain flows perfectly? Try to solve these 10 thick riddles!
1. The Riddle: I am the fancy science term used to describe the “thickness” of a liquid. What am I?
The Answer: Viscosity.
2. The Riddle: I am the famous scientist who made the original rules about how liquids are supposed to flow. Who am I?
The Answer: Sir Isaac Newton.
3. The Riddle: I am the classic baking ingredient you mix with water to create this bizarre, physics-breaking liquid. What am I?
The Answer: Cornstarch.
4. The Riddle: I am the physical action you must do to the liquid to force it to instantly turn into a solid. What am I?
The Answer: Punch it (or apply force/pressure).
5. The Riddle: I am the everyday event on a busy highway that perfectly describes how the cornstarch locks together. What am I?
The Answer: A traffic jam.
6. The Riddle: I am the invisible energy created by a loud stereo speaker that can actually make the liquid stand up and dance. What am I?
The Answer: Sound waves.
7. The Riddle: I am the state of matter that the Oobleck turns into the second you relax your hand and stop squeezing. What am I?
The Answer: A liquid.
8. The Riddle: I am the super tough, military safety gear that scientists are currently trying to build using these exact same liquids. What am I?
The Answer: Bulletproof armor.
9. The Riddle: I am the exact ratio of cornstarch to water you need to mix to make the perfect puddle. What is the ratio?
The Answer: 2 to 1 (2 cups cornstarch, 1 cup water).
10. The Riddle: I am the large, deep container you absolutely need to use so you don’t ruin your kitchen counter. What am I?
The Answer: A mixing bowl.
The Wrap Up
Oobleck is the ultimate proof that you don’t need dangerous acids or toxic metals to break the laws of physics. Sometimes, you just need a box of cornstarch and some tap water.
By understanding how microscopic traffic jams work, you can literally run across water like a superhero. If you want to dive deeper into how fluid dynamics govern everything from ocean currents to the blood in your veins, definitely read through the American Physical Society (APS). Now go make a mess in the kitchen!
Cited Sources & Evidence
- Institute of Physics (IOP)
- Science Buddies
- National Science Foundation (NSF)
- American Physical Society (APS)