What is a whirlpool?

Have you ever pulled the plug in your bathtub and watched the water do a little spinny dance down the drain? That tiny swirling funnel is actually a mini whirlpool! But did you know that out in the wild ocean, these spinning watery tornados can grow large enough to swallow a whole school bus?! Join Mira and Finn on an incredible underwater adventure to discover the wild science behind why water loves to spin! We'll learn how the exact same space-math that spins galaxies—called the conservation of angular momentum—also controls your bath water! You'll travel to Norway to see the strongest tidal whirlpool in the world, where 110 billion gallons of ocean water squeeze through a tiny gap every six hours. Then, we will listen for a roaring Scottish whirlpool crashing against an underwater pyramid, and sail over to Japan to marvel at massive 66-foot-wide spinning vortexes! Are giant whirlpools just nature showing off, or do they serve a secret purpose as giant ocean blenders for hungry sea creatures? Plus, we finally bust the famous myth about spinning toilets! Grab your life jacket and let's dive into the spinning world of whirlpools!

Transcript

SPEAKER_01 0:48

Welcome to Science Is Not Boring by kidopoly.com. I'm Mira. And I'm Finn. Today we have a very special shout out to Henry in San Clemente, California, who asked all about the science of whirlpools. Great question, Henry. This one is for you. But before we dive in, Finn, did you know there is a whirlpool in Scotland so loud you can hear it roaring from 10 miles away?

SPEAKER_00 1:15

10 miles? That's like hearing a lawnmower from the next town over.

SPEAKER_01 1:21

Exactly. The powerful roaring sound is made when the strong ocean currents crash against a huge pyramid-shaped rock hiding underwater.

SPEAKER_00 1:31

Wow, okay. I am definitely impressed by how powerful water is.

SPEAKER_01 1:37

Well, don't worry, we are safe on land today. Because today we are exploring why water loves to spin.

SPEAKER_00 1:44

From the little swirly drain in your bathtub to massive roaring ocean vortexes.

SPEAKER_01 1:50

We are pulling the plug on the secrets of whirlpools right after this. So, Finn, think about when you pull the plug in the bathtub. What does the water do?

SPEAKER_00 2:00

It doesn't just go straight down, it does this little spinny dance, swirling round and round into a tiny funnel.

SPEAKER_01 2:08

Yes, that spinning funnel is a tiny whirlpool. And the science behind it is a physics rule called the conservation of angular momentum.

SPEAKER_00 2:17

Wait, angular moment what?

SPEAKER_01 2:20

The exact same math that governs a spinning galaxy in outer space is what makes your bathwater spin. It's a universal law.

SPEAKER_00 2:29

A bathtub is like a mini galaxy.

SPEAKER_01 2:31

Kind of. It's all about how mass, size, and speed work together. Think of an ice skater spinning on the ice. When they have their arms stretched out, they spin kind of slowly, right?

SPEAKER_00 2:44

Yeah, but when they pull their arms in tight to their chest, they spin super fast.

SPEAKER_01 2:49

Exactly! That is the conservation of angular momentum in action. If the size of the spinning circle shrinks, the speed has to go up, so the total momentum stays balanced.

SPEAKER_00 3:01

Oh, so when the bathtub water gets pulled toward the tiny drain, it's like the skater pulling their arms in.

SPEAKER_01 3:07

You got it! The water is moving toward a smaller space, so it starts to spin faster and tighter until it creates a dip in the middle.

SPEAKER_00 3:16

But wait, does the ocean have a giant plug at the bottom? How do ocean whirlpools happen?

SPEAKER_01 3:22

No giant ocean plug. In the wild, whirlpools happen when super strong tides are forced through a really narrow gap between islands or rocks.

SPEAKER_00 3:32

So instead of a drain, the water is being squeezed through a tight hallway.

SPEAKER_01 3:36

Exactly! When billions of gallons of rushing tide crash into underwater mountains or deep holes, the water twists and starts to spin. Whoa, that sounds way more intense than a bathtub. Oh, it is. The strongest tidal whirlpool in the whole world is in Norway. A place called Saltstromen. Saltstromen? Where exactly in Norway? It's just above the Arctic Circle, near a town called Boder. There is a narrow strait that connects two massive fjords.

SPEAKER_00 4:10

And let me guess, a lot of water tries to squeeze through.

SPEAKER_01 4:14

A mind-blowing amount! Every six hours, the ocean tide pushes 400 million cubic metres of water through a gap that is only 490 feet wide. 400 million cubic metres? How much is that? That's about 110 billion gallons of water. Enough to fill over 160,000 Olympic swimming pools.

SPEAKER_00 4:42

All squeezing through a little gap every six hours. The water must be moving so fast.

SPEAKER_01 4:48

It reaches speeds of 25 miles per hour. That is 22 knots, which is crazy fast for a boat to navigate. How big do the actual whirlpools get? The spinning funnels at Saltstrom can be up to 33 feet wide and 16 feet deep.

SPEAKER_00 5:07

16 feet deep? You could easily fit a whole school bus inside a hole that big. Wait, why would anyone want to live next to a giant swirling washing machine?

SPEAKER_01 5:28

Because the spinning water keeps the strait from freezing in the winter. And all that swirling stirs up food from the ocean floor. Oh, I bet all those snacks attract a ton of fish. It's a fisherman's paradise. The world record for catching a type of fish called a coalfish with a pole was set right there, weighing 50 pounds.

SPEAKER_00 5:50

Whoa, that fish is heavier than my little cousin.

SPEAKER_01 5:53

But if you think Norway is wild, let's talk about the one in Scotland. It's called the Gulf of Corivreken. Corrivreken? Is that the one you mentioned earlier? The one that roars? Yes. It's located between two Scottish islands called Jura and Scarborough. The water rushes in at about 10 miles per hour, but it hits a huge, pyramid-shaped rock hiding underwater. An underwater pyramid? That sounds like a trap. It basically is. The rushing water hits the rock, which rises from a depth of 230 feet, creating giant whirlpools and waves up to 30 feet tall.

SPEAKER_00 6:35

And that's what makes the roaring sound that you can hear 10 miles away. Exactly.

SPEAKER_01 6:40

The roar is so famous, you can hear the powerful rushing water from 10 miles away.

SPEAKER_00 6:46

That is so loud! It really sounds like a giant, roaring, natural washing machine.

SPEAKER_01 6:53

It totally is. The strong currents hit that underwater rock, and the rushing water gets thrown up and twisted around to create massive standing waves and giant spinning funnels. So the shape of the sea floor makes it spin. Exactly. It pushes the water in a circular motion, creating an amazing twisting puzzle of currents. It is incredible to see how the wild ocean moves.

SPEAKER_00 7:19

Wow, that is so cool! I never realised that nature could create such wild underwater features.

SPEAKER_01 7:25

It really is. But size-wise, Japan has a whirlpool that might beat them all. The Naruto whirlpools. Like the ninja! Wait, how big do they get? During spring tides, the Naruto whirlpools can reach 66 feet in diameter. The water level on one side of the strait is almost five feet higher than the other side.

SPEAKER_00 7:47

So it's basically a mini waterfall trying to level itself out while spinning. Exactly.

SPEAKER_01 7:53

The Pacific Ocean water is rushing into the inland sea, creating massive, roaring circles that tourists actually go see on special sightseeing boats. Boats? That sounds like the most incredible sightseeing trip. The boats are perfectly safe. But it's incredible how nature creates these massive spinning forces just by moving water through tight spaces.

SPEAKER_00 8:18

But do whirlpools actually do anything important? Or are they just nature showing off? They are super important!

SPEAKER_01 8:26

Remember how we said they stir up fish in Norway? Whirlpools act like giant blenders for the ocean.

SPEAKER_00 8:32

Giant blenders? Are they making fish smoothies?

SPEAKER_01 8:36

Sort of. They pull nutrients from the deep dark bottom of the ocean, all the way up to the surface where the sunlight is.

SPEAKER_00 8:44

Oh, so all the little sea creatures get a free buffet.

SPEAKER_01 8:47

Exactly! Phytoplankton, the tiny plants of the sea, use those nutrients to grow. And then little fish eat the plankton. And then bigger fish eat the little fish. You got it. And the crazy currents give seabirds an easy dinner, because smaller fish get temporarily dazed by the spinning water.

unknown 9:07

Haha!

SPEAKER_00 9:08

So it's a dizzy fish buffet for the birds.

SPEAKER_01 9:11

Exactly. And here is another wild fact. Some smaller whirlpools actually form at the base of huge waterfalls. Oh, like Niagara Falls. Yes. The Niagara Whirlpool is a massive basin where the rushing river takes a sharp 90-degree turn, creating a giant counterclockwise spin.

SPEAKER_00 9:31

Okay, speaking of spinning, is it true that toilets and bathtubs spin in different directions, depending on what side of the world you live on?

SPEAKER_01 9:39

The Coriolis effect. It's actually a famous myth. The Earth's rotation only affects huge systems like hurricanes. No way!

SPEAKER_00 9:49

So why does my bathtub water spin at all?

SPEAKER_01 9:52

It's just random. It depends on the shape of your tub, microscopic bumps in the porcelain, or even how the water was moving when you pulled your foot out.

unknown 10:01

Haha.

SPEAKER_00 10:02

So my big toe is more powerful than the rotation of the Earth.

SPEAKER_01 10:06

In your bathtub, yes. Alright, Finn, it is time for the whirlpool quiz. Are you ready?

SPEAKER_00 10:13

Okay, my brain is spinning, but I'm ready.

SPEAKER_01 10:16

First question. What is the scientific rule that makes a spinning ice skater and a whirlpool spin faster when they pull inward? Next one. How many gallons of water rush through the Saltstramen Strait in Norway every six hours? Question three. What is the name of the loud, roaring whirlpool that is located in Scotland? Here's number four. How heavy was the world record coalfish caught near the Norwegian whirlpool? Last question. In Japan, how wide can the massive Naruto whirlpools get? Great job! Let's see how you did. The first answer is conservation of angular momentum. For question two, 110 billion gallons of water. Number three, the answer is it is the Gulf of Corrievreken. Question 4. The record fish caught weighed exactly 50 pounds. And the final answer is the Naruto whirlpools can get up to 66 feet wide.

SPEAKER_00 11:42

Wow, I will never look at my bathtub drain the same way again. It's like a tiny Naruto whirlpool right in my house. Just keep an eye on that spinny dance. Good idea. If you guys had fun spinning around the world with us today, please leave us a five-star review.

SPEAKER_01 11:59

Yes, if you think the conservation of Angular Momentum is as cool as a spinning ice skater, just scroll down and tap the five stars on your app.

SPEAKER_00 12:08

And don't forget to head over to our site, kidopoly.com. We've got tons of fun learning games and activities there.

SPEAKER_01 12:15

Absolutely! We love hearing from you. So if you want to shout out on the show like Henry, or just want to say hi, email us at hello at kidopoly.com.

SPEAKER_00 12:27

I wonder what Henry is going to investigate next.

SPEAKER_01 12:30

Well, whatever it is, we're ready for it. See you next time on Science Is Not Boring. Bye everyone.