0:00:05 > 0:00:08# If you've got a question and you don't know where to go
0:00:08 > 0:00:11# Ask Nina for some help Cos she's got a science show
0:00:11 > 0:00:14# She makes sense of her senses While helping all her fans
0:00:14 > 0:00:17# By doing her experiments with potions and with bangs
0:00:17 > 0:00:19- # Touch your tongue - Tongue
0:00:19 > 0:00:20- # Fingers - Fingers
0:00:20 > 0:00:22- # Eyes- Eyes - Ears- Ears
0:00:22 > 0:00:23- # Nose- Nose
0:00:23 > 0:00:26# Nina and the Neurons find out what you need to know
0:00:26 > 0:00:29# Nina and the Neurons find out what you need to know
0:00:29 > 0:00:32# Luke he helps us with our eyes and Felix with our touch
0:00:32 > 0:00:35# Ollie sniffs out smells and scents and Belle she hears so much
0:00:35 > 0:00:38# Bud is Ollie's brother he helps us with our taste
0:00:38 > 0:00:41# They're Nina's little Neurons and they're coming to your place
0:00:41 > 0:00:43- # Touch your tongue - Tongue
0:00:43 > 0:00:44- # Fingers- Fingers
0:00:44 > 0:00:46- # Eyes- Eyes - Ears- Ears
0:00:46 > 0:00:47- # Nose- Nose
0:00:47 > 0:00:50- # Nina and the Neurons find out what you need to know- Yeah!
0:00:50 > 0:00:53# Nina and the Neurons find out what you need to know
0:00:53 > 0:00:55# Oh, yeah! #
0:00:56 > 0:00:58There! Finished. Oh, hello!
0:00:58 > 0:01:02I've just been making my very own waterfall. Watch this.
0:01:03 > 0:01:05SHE LAUGHS
0:01:09 > 0:01:13Who needs water when you've got sticky notes?
0:01:13 > 0:01:15I can use these later on.
0:01:15 > 0:01:19Oh! I hear a beep, I see a flash, I wonder what they're going to ask.
0:01:19 > 0:01:21COMPUTER BEEPS
0:01:24 > 0:01:26Hi, Nina!
0:01:26 > 0:01:27Hi!
0:01:27 > 0:01:29We've got a question for you.
0:01:29 > 0:01:33How are waterfalls made?
0:01:33 > 0:01:36That's a great question. How are waterfalls made?
0:01:36 > 0:01:40Waterfalls are amazing to see, but what makes the water fall like that?
0:01:40 > 0:01:44Why don't you come to my workshop and we'll investigate?
0:01:44 > 0:01:48BOTH: See you soon, Nina. Bye!
0:01:48 > 0:01:52Bye! Well, I'm going to need some help to answer this one
0:01:52 > 0:01:53and I know just who to ask.
0:01:53 > 0:01:56OK, Neurons, time to get to work!
0:02:10 > 0:02:12ALL: Neurons at the ready, Nina.
0:02:12 > 0:02:16OK, today's question is, "How are waterfalls made?"
0:02:16 > 0:02:19Which Neuron do you think would be most useful
0:02:19 > 0:02:21in helping us find the answer?
0:02:21 > 0:02:23ALL: Me! Me! Me!
0:02:23 > 0:02:26Will it be fabulous Felix?
0:02:26 > 0:02:30I can help so very much if you need the sense of touch.
0:02:30 > 0:02:32Will it be beautiful Belle?
0:02:32 > 0:02:34I send messages to brain from ear.
0:02:34 > 0:02:36If there's a sound, I'll help you hear.
0:02:36 > 0:02:38Will it be lovely Luke?
0:02:38 > 0:02:40For looking and seeing, day or night,
0:02:40 > 0:02:43I'll help you with your sense of sight.
0:02:43 > 0:02:45Will it be awesome Ollie?
0:02:45 > 0:02:47If it's pongy or whiffy, but you can't tell,
0:02:47 > 0:02:50my messages help your sense of smell.
0:02:50 > 0:02:51Or will it be baby Bud?
0:02:51 > 0:02:56Sour, salty, bitter or sweet, I'm your taste buddy whenever you eat.
0:02:59 > 0:03:02- It's Belle! - CHEERING
0:03:02 > 0:03:04Go, Belle! Go, Belle! Go, Belle!
0:03:04 > 0:03:09Go, Belle! Go, Belle! Go, Belle!
0:03:09 > 0:03:12Brilliant! I'm all ears, Nina.
0:03:12 > 0:03:15Today's question is, "How are waterfalls made?"
0:03:15 > 0:03:19Because waterfalls make lots of noise, Belle will be helping us,
0:03:19 > 0:03:22but stand by, Neurons. I may need help from all of you.
0:03:22 > 0:03:26I need to get the workshop ready before the Explorers arrive.
0:03:28 > 0:03:32Ollie likes eating prawns and Maya loves bodyboarding in the sea,
0:03:32 > 0:03:36but they both want to know, "How are waterfalls made?"
0:03:36 > 0:03:38Some waterfalls are really big.
0:03:38 > 0:03:41How are waterfalls made?
0:03:41 > 0:03:46So, today, for one day only, Ollie and Maya become the Explorers!
0:03:51 > 0:03:53- Hi, guys! - BOTH: Hi, Nina!
0:03:53 > 0:03:56Welcome to my workshop and thank you for your great question,
0:03:56 > 0:03:59"How are waterfalls made?" To find out,
0:03:59 > 0:04:02let's start by using our senses.
0:04:02 > 0:04:06ALL: Whoop-woo! A senses experiment! We're ready, Nina.
0:04:06 > 0:04:09First, let's find out more about what a waterfall is
0:04:09 > 0:04:11by taking a look at this model.
0:04:11 > 0:04:16Some rivers have waterfalls and I've got some little pretend leaves here
0:04:16 > 0:04:19that I'm going to put into our model river
0:04:19 > 0:04:21so you can see how the water moves.
0:04:24 > 0:04:26Whoa!
0:04:28 > 0:04:29Hee-hee!
0:04:31 > 0:04:34The river runs downhill over the rock,
0:04:34 > 0:04:38but the rock stops here and there's a big step down,
0:04:38 > 0:04:41so the water falls over the edge into the pool below
0:04:41 > 0:04:43and that's why it's called a waterfall.
0:04:43 > 0:04:46There's lots of different waterfalls in here.
0:04:46 > 0:04:49There's one there, one there and a big one here.
0:04:49 > 0:04:54Now, let's have a look at some real waterfalls in action.
0:04:54 > 0:04:58This is Niagara Falls. It's really big, isn't it?
0:04:58 > 0:05:00BOTH: Yes!
0:05:00 > 0:05:04In fact, it's one of the biggest waterfalls in the world
0:05:04 > 0:05:08and it makes a lot of noise. The more water that falls over the edge,
0:05:08 > 0:05:10the more noise a waterfall makes.
0:05:10 > 0:05:12And waterfalls aren't made by people,
0:05:12 > 0:05:15they're part of our amazing world.
0:05:15 > 0:05:17Now, let's have a look at another one.
0:05:17 > 0:05:21- What do you see here? - Lots and lots of rock.- That's right.
0:05:21 > 0:05:25There are lots of different layers of rock on top of each other. Hmm.
0:05:25 > 0:05:29Oh, I wonder if these rock layers have something to do with how
0:05:29 > 0:05:32a waterfall is made. Let's find out!
0:05:32 > 0:05:34Now, there are lots of different types of rock.
0:05:34 > 0:05:37Some are really hard and some are softer,
0:05:37 > 0:05:40like a pencil wears away when we use it to draw.
0:05:40 > 0:05:42In front of us we have two types of rock
0:05:42 > 0:05:46and we're going to see which one is hardest by scratching them
0:05:46 > 0:05:50with sandpaper and seeing which one wears away or becomes smaller.
0:05:50 > 0:05:52- Are you ready? - BOTH: Yes!
0:05:52 > 0:05:57Go! And we'll scratch the dark rock first. Phew!
0:05:57 > 0:05:59LOUD SCRAPING
0:06:00 > 0:06:04Oh, that's a really funny scratchy sound!
0:06:04 > 0:06:07It makes me feel quite shuddery! Woo!
0:06:16 > 0:06:18Phew! Oh!
0:06:18 > 0:06:20Now, let's move on to the white rock.
0:06:33 > 0:06:34Oh!
0:06:34 > 0:06:36This is hard work.
0:06:36 > 0:06:39Why don't we stop and have a look at our rocks?
0:06:40 > 0:06:43OK, now which one was the easiest to wear away?
0:06:43 > 0:06:45- The white one.- Yeah, the white one!
0:06:45 > 0:06:48The white one rubbed away really easily.
0:06:48 > 0:06:50So which one do you think is the hardest?
0:06:50 > 0:06:52The dark rock.
0:06:52 > 0:06:54Yeah, the dark rock is hardest
0:06:54 > 0:06:56because it's hardly worn away at all.
0:06:56 > 0:07:01Now, all rocks feel hard to us, but some rocks are harder than others,
0:07:01 > 0:07:05and harder rocks are more difficult to rub away than softer rocks.
0:07:05 > 0:07:09BELLE: 'Oh! So waterfalls are made when the bottom of a river
0:07:09 > 0:07:13'makes a step and the water falls over the edge.'
0:07:13 > 0:07:15- FELIX:- 'All rocks feel hard to us,
0:07:15 > 0:07:18'but some rocks are harder than others.'
0:07:18 > 0:07:22- LUKE:- 'Softer rock is easier to wear away than harder rock.'
0:07:22 > 0:07:26That's right, Neurons! Maybe hard and soft rocks have something to do
0:07:26 > 0:07:31with how a waterfall is made. Let's go somewhere noisy to find out.
0:07:35 > 0:07:39OLLIE: On the road again. I really enjoy our trips with Nina.
0:07:39 > 0:07:44- BELLE:- Nina said we're going somewhere really noisy! Hoo-hoo!
0:07:44 > 0:07:48- I'm going to be busy.- BUD:- Oh! Oh! Maybe we're going to see a rocket!
0:07:48 > 0:07:51That's really noisy! Lift off!
0:07:51 > 0:07:55FELIX: I don't think anything could be noisier than you, Bud.
0:07:57 > 0:08:01So, in order to answer your question, "How are waterfalls made?"
0:08:01 > 0:08:04What better place to come than a real waterfall?
0:08:04 > 0:08:07- LAUGHING:- Isn't it lovely? - BOTH: Yes!
0:08:12 > 0:08:15So far, we've found out that waterfalls are made
0:08:15 > 0:08:19when the bottom of the river makes a step and the water falls over
0:08:19 > 0:08:22the edge, and we also found out that some rock is hard
0:08:22 > 0:08:27and some is soft, and they can also be found in layers.
0:08:27 > 0:08:29Can you see any layers of rock here?
0:08:29 > 0:08:30- There!- There!
0:08:30 > 0:08:34Yes! The top layer of rock is made from hard rock
0:08:34 > 0:08:35and it's harder to wear away.
0:08:35 > 0:08:39The softer layer of rock is that layer underneath
0:08:39 > 0:08:43and it's easier to wear away. In fact, look...
0:08:43 > 0:08:48You can see the water has worn it away so much, it's left a big hole.
0:08:49 > 0:08:52Oh, ho, ho! It's quite noisy, isn't it?
0:08:52 > 0:08:54BOTH: Yes!
0:08:54 > 0:09:00You can say that again! It's like the noisiest shower ever!
0:09:00 > 0:09:02And look at all the layers.
0:09:03 > 0:09:06The water has worn away the rock at the bottom
0:09:06 > 0:09:10and the rock at the top is sticking out more than the rock underneath,
0:09:10 > 0:09:14and it's called an overhang because it's hanging over.
0:09:14 > 0:09:16- Over...- Hang!- Over...- Hang!
0:09:16 > 0:09:18BOTH: Got it!
0:09:18 > 0:09:22And look, there's a big pool where the waterfall lands
0:09:22 > 0:09:24and continues its journey down the river.
0:09:24 > 0:09:28- OLLIE:- So, now we know waterfalls sometimes have an overhang.
0:09:28 > 0:09:32- FELIX:- An overhang is where rocks stick out further
0:09:32 > 0:09:34on top than underneath.
0:09:34 > 0:09:36Exactly, Neurons!
0:09:36 > 0:09:38I wonder if we could make our own waterfall.
0:09:38 > 0:09:41Let's go back to the workshop to find out.
0:09:42 > 0:09:45So, you asked, "How are waterfalls made?"
0:09:45 > 0:09:49And so far we've discovered that when a river flows over
0:09:49 > 0:09:52hard and soft rock, the rocks get worn away differently
0:09:52 > 0:09:55and make a step which the water falls over.
0:09:55 > 0:10:00But now we want to see if we can make our very own waterfall.
0:10:00 > 0:10:03So, let's try. We're going to imagine that this sand
0:10:03 > 0:10:06is our softer rock and it wears away easily.
0:10:06 > 0:10:10And underneath this sand is a layer of hard rock, like this one,
0:10:10 > 0:10:13and it's harder to wear away.
0:10:13 > 0:10:16Now, let's see what happens when we add our very own river
0:10:16 > 0:10:18by using this watering can.
0:10:26 > 0:10:27SHE GASPS
0:10:31 > 0:10:32Oh!
0:10:32 > 0:10:34Do you see what's happening?
0:10:34 > 0:10:37The sand's going downwards.
0:10:37 > 0:10:40Yeah, our softer rock is getting worn away.
0:10:44 > 0:10:46The water's rubbing it away,
0:10:46 > 0:10:50but the hard rock underneath is not being worn away at all.
0:10:51 > 0:10:53SHE GASPS
0:10:58 > 0:11:02Look! Now lots more soft rock is getting worn away,
0:11:02 > 0:11:06we can see the hard rock sticking out and making an edge.
0:11:10 > 0:11:14And that edge makes a waterfall!
0:11:14 > 0:11:17ALL: Waterfall!
0:11:17 > 0:11:20Yay! We've made our own waterfall!
0:11:20 > 0:11:22SHE LAUGHS
0:11:22 > 0:11:24And...
0:11:24 > 0:11:27this is exactly how a waterfall works.
0:11:30 > 0:11:35- BUD:- Wow, so the soft rock gets worn away easier than the harder rock.
0:11:35 > 0:11:38BELLE: The harder rocks end up
0:11:38 > 0:11:40sticking out and making a waterfall.
0:11:40 > 0:11:42That's right, Neurons.
0:11:42 > 0:11:46# Nina and the Neurons! #
0:11:46 > 0:11:50So, your question was, "How are waterfalls made?"
0:11:50 > 0:11:51I think we've answered it.
0:11:51 > 0:11:55BUD: 'Some rivers have waterfalls where the bottom of the river
0:11:55 > 0:11:59'forms a step and water falls over the edge.'
0:11:59 > 0:12:02- OLLIE:- 'Soft rock is easier to wear away than harder rock.'
0:12:02 > 0:12:07- FELIX:- 'As the river runs over the rock, it wears away the softer rock
0:12:07 > 0:12:11- 'quicker than the hard rock. - LUKE: 'And that makes an overhang.'
0:12:11 > 0:12:13- BELLE:- 'Waterfalls can be really loud!
0:12:13 > 0:12:16'I love all the splashing noises!'
0:12:16 > 0:12:18So, I hope that's answered your question.
0:12:18 > 0:12:21BOTH: Thanks, Nina. Bye!
0:12:21 > 0:12:22You're welcome! Bye!
0:12:25 > 0:12:29If you want to know more about the science that's all around us,
0:12:29 > 0:12:33go to the Nina section on the CBeebies website. Have fun!
0:12:33 > 0:12:39# Every day the sun comes up it brightens up the sky
0:12:39 > 0:12:41# A brand-new day to understand
0:12:41 > 0:12:45- # A chance to ask ourselves why - Why?
0:12:45 > 0:12:50- # There's a world of possibilities outside our front door- Front door
0:12:50 > 0:12:55# So every day take a look around and explore
0:12:55 > 0:12:58- # Explore,- explore,- explore - explore
0:12:58 > 0:13:04- # Exploring in the garden- Grass - exploring in the park- Rivers
0:13:04 > 0:13:10- # Exploring in the daytime- Mountains - And even when it's dark- Planets
0:13:10 > 0:13:14# Look at the Earth look at the sky Look at the world before us
0:13:14 > 0:13:17- # Explore,- explore,- explore,- explore
0:13:17 > 0:13:20# We're always on the lookout
0:13:20 > 0:13:23- # We're Earth explorers - O-oh o-oh
0:13:23 > 0:13:26- # We're Earth explorers - O-oh o-oh
0:13:26 > 0:13:29# We're Earth explorers. #
0:13:30 > 0:13:33Exploring is about looking at the world around us,
0:13:33 > 0:13:36asking why and finding out the answer.
0:13:36 > 0:13:39Whether it's deep underground, at the end of your playground
0:13:39 > 0:13:43or above the clouds, keep exploring our exciting world.
0:13:43 > 0:13:46See you again soon. Bye.
0:13:46 > 0:13:47ALL: Bye.
0:13:47 > 0:13:50Subtitles by Red Bee Media Ltd