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 > 0:00:20- # Touch your tongue!- Tongue! - Fingers!- Fingers!
0:00:20 > 0:00:23- # Eyes!- Eyes!- Ears!- Ears! - 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 > 0:00:39# Bud is Ollie's brother, he helps us with our taste
0:00:39 > 0:00:41# They're Nina's little Neurons and they're coming to your place
0:00:41 > 0:00:45- # Touch your tongue!- Tongue! - Fingers!- Fingers!
0:00:45 > 0:00:48- # Eyes!- Eyes!- Ears!- Ears! - Nose!- Nose!
0:00:48 > 0:00:51- # Nina and the Neurons find out what you need to know!- Yeah!
0:00:51 > 0:00:56- # Nina and the Neurons find out what you need to know!- Oh, yeah!- #
0:00:56 > 0:00:59Oh, dear! Ow! Oh!
0:00:59 > 0:01:02Oh, hello there. I'm just making a cave.
0:01:02 > 0:01:05But it's really dark in here, I can't see a thing.
0:01:05 > 0:01:07Ah! This should help.
0:01:07 > 0:01:09Whoo!
0:01:09 > 0:01:10Oooh!
0:01:10 > 0:01:14- BEEPING - Oh, I hear a beep, I see a flash.
0:01:14 > 0:01:16I wonder what they're going to ask.
0:01:21 > 0:01:23- ALL: Hi, Nina.- Hi!
0:01:23 > 0:01:27- We've got a question for you. - How are caves made?
0:01:27 > 0:01:31That's a great question, how are caves made?
0:01:31 > 0:01:35Caves are great fun to look inside and explore, but why are they there?
0:01:35 > 0:01:39Why don't you come down to my workshop and we'll investigate?
0:01:39 > 0:01:41- ALL: See you soon, Nina. Bye!- Bye!
0:01:41 > 0:01:45I'm going to need some help to answer this one,
0:01:45 > 0:01:49and I know just who to ask. OK, Neurons, time to get to work.
0:02:04 > 0:02:07ALL: Neurons at the ready, Nina.
0:02:07 > 0:02:10Today's question is how are caves made?
0:02:10 > 0:02:13Which Neuron do you think would be most useful
0:02:13 > 0:02:17- in helping us find the answer? - ALL: Me! Me!
0:02:17 > 0:02:19Will it be...fabulous Felix?
0:02:19 > 0:02:23I can help so very much if you need the sense of touch.
0:02:23 > 0:02:25Will it be beautiful Belle?
0:02:25 > 0:02:27I send messages to brain from ear,
0:02:27 > 0:02:30if there's a sound, I'll help you hear.
0:02:30 > 0:02:32Will it be lovely Luke?
0:02:32 > 0:02:34For looking and seeing, day or night,
0:02:34 > 0:02:37I'll help you with your sense of sight.
0:02:37 > 0:02:38Will it be awesome Ollie?
0:02:38 > 0:02:41If it's pongy or whiffy but you can't tell,
0:02:41 > 0:02:43my messages help your sense of smell.
0:02:43 > 0:02:46Or will it be baby Bud?
0:02:46 > 0:02:51Sour, salty, bitter or sweet, I'm your taste buddy whenever you eat.
0:02:54 > 0:02:56It's Belle!
0:02:56 > 0:02:59ALL: Go, Belle! Go, Belle!
0:02:59 > 0:03:04Go, Belle! Go, Belle! Go, Belle! Go, Belle!
0:03:04 > 0:03:06Brilliant. I'm all ears, Nina.
0:03:06 > 0:03:09Today's question is how are caves made?
0:03:09 > 0:03:11Because caves are full of sounds and echoes,
0:03:11 > 0:03:14Belle will be helping us today.
0:03:14 > 0:03:18But stand by, Neurons, I may need help from all of you.
0:03:18 > 0:03:22I need to get the workshop ready before the explorers arrive.
0:03:22 > 0:03:24Joshua likes sailing with his family,
0:03:24 > 0:03:29Parisa loves doing cartwheels, and Raymond's favourite colour is blue.
0:03:29 > 0:03:32But they all want to know, how are caves made?
0:03:32 > 0:03:35- There's caves near my house. - How did they get there?
0:03:35 > 0:03:38What's inside the cave?
0:03:38 > 0:03:40Today, for one day only, Joshua, Parisa
0:03:40 > 0:03:43and Raymond become the explorers.
0:03:48 > 0:03:51- Hi, guys.- ALL: Hi, Nina. - Welcome to my workshop.
0:03:51 > 0:03:55Thank you for your great question, how are caves made?
0:03:55 > 0:03:58To find out the answer, let's start by using our senses.
0:03:58 > 0:04:03ALL: Whoo-whoo! A senses experiment! We're ready, Nina.
0:04:03 > 0:04:07First, let's have a look at this picture of a cave.
0:04:07 > 0:04:09What does it look like?
0:04:09 > 0:04:12- A big hole in the ground. - That's right.
0:04:12 > 0:04:15A cave is a big hole under the ground.
0:04:15 > 0:04:18It's made of rock, and often there's water in there.
0:04:18 > 0:04:25Whoo! It must have taken someone really strong to dig that!
0:04:25 > 0:04:28Actually, Bud, caves aren't made by people.
0:04:28 > 0:04:32- They're part of the world around us. - How do they get there?
0:04:32 > 0:04:36Well, this cave looks like it's got water in the walls,
0:04:36 > 0:04:40so I wonder if water has something to do with how caves are made.
0:04:40 > 0:04:41Let's find out.
0:04:41 > 0:04:44We all have two glasses of water in front of us.
0:04:44 > 0:04:48And we also have some sugar and some glass marbles.
0:04:48 > 0:04:52Let's see what happens when we mix the sugar with the water.
0:04:52 > 0:04:53Let's go.
0:04:57 > 0:04:59That's it. Get it all in there.
0:05:07 > 0:05:09Good stirring, everyone.
0:05:11 > 0:05:13You're doing really well.
0:05:15 > 0:05:17Ooh!
0:05:19 > 0:05:23- What's happened?- It disappeared. - Yes!
0:05:23 > 0:05:26The sugar disappears because it dissolves.
0:05:26 > 0:05:28Water can dissolve things.
0:05:28 > 0:05:31The sugar is still there, we just can't see it.
0:05:31 > 0:05:35So when it dissolved, it mixed in with the water.
0:05:35 > 0:05:39Now let's try dissolving these glass marbles.
0:05:39 > 0:05:41Pop them in one at a time.
0:05:46 > 0:05:48Give it a stir.
0:05:59 > 0:06:01- They're still there!- Yes!
0:06:01 > 0:06:05So water can dissolve some things, like sugar,
0:06:05 > 0:06:08but not other things, like glass marbles.
0:06:08 > 0:06:12So we know that caves aren't made by people,
0:06:12 > 0:06:14they're part of the world around us.
0:06:14 > 0:06:18And we've found out some things, like sugar, dissolve in water,
0:06:18 > 0:06:22but some things, like marbles, don't.
0:06:22 > 0:06:23That's right, Neurons.
0:06:23 > 0:06:28I wonder if water could dissolve rocks to make caves.
0:06:28 > 0:06:31We need to look into this a bit deeper to find out.
0:06:33 > 0:06:37Look at them go. I wonder where we'll end up today?
0:06:37 > 0:06:40Nina said we had to look deeper to answer the question.
0:06:40 > 0:06:44I know! The swimming pool! That's really deep.
0:06:44 > 0:06:47I hope Nina's brought her armbands!
0:06:47 > 0:06:48THEY LAUGH
0:06:48 > 0:06:50Sh, everyone, we're here.
0:06:57 > 0:07:03To answer your question, we've come to look inside a really big cave.
0:07:03 > 0:07:06So far, we've found out that caves aren't made by people
0:07:06 > 0:07:08and water can dissolve things.
0:07:08 > 0:07:13But now we want to know if water can dissolve rock to make caves.
0:07:13 > 0:07:17- Are you ready to do some exploring? - ALL: Yeah!
0:07:17 > 0:07:18Let's go!
0:07:18 > 0:07:20Remember, caves can be dangerous,
0:07:20 > 0:07:24so you should always have an adult with you when you're near one.
0:08:02 > 0:08:07Look at this, explorers, this is where a new cave is forming.
0:08:07 > 0:08:09What do you notice?
0:08:09 > 0:08:12- There's water in there.- Yeah.
0:08:12 > 0:08:15Rainwater from above ground is coming down into the cave,
0:08:15 > 0:08:18and it's dissolving the rock to make a hole.
0:08:18 > 0:08:22Only a small amount of rock has been dissolved by the water so far.
0:08:22 > 0:08:26Slowly, the water will dissolve more of the rock
0:08:26 > 0:08:29until, eventually, it's a big underground cave.
0:08:29 > 0:08:34But it will take a very, very, very long time for a cave to form.
0:08:34 > 0:08:36Who wants to see a big one?
0:08:36 > 0:08:38Hee-hee-hee! Let's go!
0:08:40 > 0:08:43Look at this! Hello!
0:08:43 > 0:08:45ALL: Hello!
0:08:45 > 0:08:48Hellooo!
0:08:48 > 0:08:51I love the sound of echoes.
0:08:51 > 0:08:53It's huge, isn't it?
0:08:53 > 0:08:56And look at all the water on the walls.
0:08:57 > 0:09:00There's lots of rainwater coming down from above,
0:09:00 > 0:09:06and it has very slowly dissolved this rock to make a really big cave.
0:09:06 > 0:09:10And what do you notice about the cave walls?
0:09:10 > 0:09:12They're all bumpy.
0:09:12 > 0:09:14Yes, the walls are bumpy.
0:09:14 > 0:09:18That's because there are different types of rock here.
0:09:18 > 0:09:21Some of the rock is like our sugar, and it dissolves in water.
0:09:21 > 0:09:24The other type of rock is a bit like the marbles
0:09:24 > 0:09:28and doesn't dissolve in water, so it's still there.
0:09:28 > 0:09:33So it takes a very, very, very long time for a cave to form.
0:09:33 > 0:09:37Caves are made by water dissolving the rock underground.
0:09:37 > 0:09:39How fascinating!
0:09:39 > 0:09:41That's right, Neurons.
0:09:41 > 0:09:44Let's see if we can make our own cave.
0:09:47 > 0:09:50So you asked, how are caves made?
0:09:50 > 0:09:54So far, we've found out that caves are part of the world around us
0:09:54 > 0:09:58and are made by rainwater slowly dissolving the rock underground.
0:09:58 > 0:10:02Let's see if we can make our very own cave.
0:10:02 > 0:10:07Now, let's imagine that this is the ground.
0:10:07 > 0:10:13It's made of two types of rock, the modelling clay is one type of rock,
0:10:13 > 0:10:17and the sugar cubes is another type of rock.
0:10:17 > 0:10:21We're going to see if we can make our own cave by making it rain.
0:10:21 > 0:10:25I've added some blue colouring so it's easier to see what's happening.
0:10:25 > 0:10:27Here we go!
0:10:54 > 0:10:58- Do you see what's happening? - The sugar is dissolving.
0:10:58 > 0:11:02Yes! The rainwater is dripping through
0:11:02 > 0:11:04and making the sugar cubes dissolve.
0:11:04 > 0:11:09And when the sugar dissolves, it's taken away by the water,
0:11:09 > 0:11:12leaving a big hole underneath.
0:11:12 > 0:11:14We've made our own cave!
0:11:14 > 0:11:18So caves are made by rainwater dripping underground
0:11:18 > 0:11:22and dissolving the rock to make a big hole!
0:11:22 > 0:11:24Brilliant!
0:11:24 > 0:11:25That's right, Belle.
0:11:25 > 0:11:29And there are different types of rock in caves.
0:11:29 > 0:11:32Some are dissolved by water and some aren't.
0:11:32 > 0:11:37The roof here and in our model hasn't been dissolved.
0:11:37 > 0:11:41- Are you ready to go back above ground, explorers?- ALL: Yeah!
0:11:41 > 0:11:45# Nina and the Neurons! #
0:11:46 > 0:11:49So your question was, how are caves made?
0:11:49 > 0:11:51I think we've answered it.
0:11:51 > 0:11:55We found out that caves aren't made by people.
0:11:55 > 0:11:59Most of them are made by rainwater getting underground.
0:11:59 > 0:12:00Drip, drip, drip!
0:12:00 > 0:12:04Water dissolves things like sugar and some types of rock -
0:12:04 > 0:12:06very slowly.
0:12:06 > 0:12:10Water dissolves some rocks underground, making a big hole.
0:12:10 > 0:12:15But some rocks don't dissolve, and that makes the roof.
0:12:15 > 0:12:17Now, that's what I call clever!
0:12:17 > 0:12:21So I hope that's answered your question.
0:12:21 > 0:12:23ALL: Thanks, Nina. Bye.
0:12:23 > 0:12:26You're welcome. Bye.
0:12:28 > 0:12:32If you want to know more about science all around us,
0:12:32 > 0:12:36go to the Nina section on the CBeebies website. Have fun!
0:12:36 > 0:12:42# Every day the sun comes up, it brightens up the sky
0:12:42 > 0:12:44# A brand-new day to understand
0:12:44 > 0:12:47# A chance to ask ourselves why
0:12:47 > 0:12:48# Why?
0:12:48 > 0:12:54# There's a world of possibilities outside our front door
0:12:54 > 0:12:58# So every day, take a look around and explore
0:12:58 > 0:13:01# Explore, explore, explore, explore
0:13:01 > 0:13:07- # Exploring in the garden!- Grass! - Exploring in the park!- Rivers!
0:13:07 > 0:13:10- # Exploring in the daytime! - Mountains!
0:13:10 > 0:13:13- # And even when it's dark!- Planets!
0:13:13 > 0:13:18# Look at the earth, look at the sky look at the world before us
0:13:18 > 0:13:21# Explore, explore, explore, explore
0:13:21 > 0:13:24# We're always on the lookout
0:13:24 > 0:13:27- # We're earth explorers - Oh-oh, oh-oh
0:13:27 > 0:13:30- # We're earth explorers - Oh-oh, oh-oh
0:13:30 > 0:13:34# We're earth explorers. #
0:13:34 > 0:13:37Exploring is about looking at the world around us,
0:13:37 > 0:13:39asking why and finding out the answer.
0:13:39 > 0:13:43Whether it's deep underground, at the end of your playground
0:13:43 > 0:13:47or way above the clouds, keep exploring our exciting world.
0:13:47 > 0:13:49See you again soon. Bye.
0:13:49 > 0:13:51ALL: Bye.