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 > 0:00:36# Ollie sniffs out smells and scents And Belle, she hears so much
0:00:36 > 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! #
0:00:55 > 0:00:58NINA CHUCKLES Oh, hello there.
0:00:58 > 0:01:01My little boats are going to have a race.
0:01:01 > 0:01:03OK. Who do you think will win? Ha-ha!
0:01:03 > 0:01:05Go.
0:01:05 > 0:01:07Oh-oh-oh-ohh!
0:01:07 > 0:01:09Oh, and just the yellow team.
0:01:09 > 0:01:10BEEPING
0:01:10 > 0:01:14I hear a beep, I see a flash! I wonder what they're going to ask!
0:01:18 > 0:01:20- BOTH:- Hi, Nina.
0:01:20 > 0:01:22Hi!
0:01:22 > 0:01:26- We've got a question for you. - Can we build floating houses?
0:01:26 > 0:01:31Oh, that's a great question. Can we build floating houses?
0:01:31 > 0:01:33We know that people build houses on land.
0:01:33 > 0:01:37But could we build a house that floats on water?
0:01:37 > 0:01:40Why don't you come down to my workshop and we'll investigate?
0:01:40 > 0:01:43- BOTH:- See you soon, Nina. Bye.
0:01:43 > 0:01:45Bye.
0:01:45 > 0:01:48I'm going to need some help to answer this one,
0:01:48 > 0:01:50and I know just who to ask.
0:01:50 > 0:01:52OK, Neurons, time to get to work.
0:02:08 > 0:02:10- ALL:- Neurons at the ready, Nina.
0:02:10 > 0:02:14OK. Today's question is, can we build floating houses?
0:02:14 > 0:02:18Now, which Neuron would be most useful in helping us find the answer?
0:02:21 > 0:02:22It's Luke.
0:02:22 > 0:02:27- ALL CHANT:- Go, Luke! Go, Luke! Go, Luke! Go, Luke!
0:02:27 > 0:02:30Go, Luke! Go, Luke! Go, Luke!
0:02:30 > 0:02:34Cool, Nina! I'll be looking out to help you.
0:02:34 > 0:02:37Today's question is, can we build floating houses?
0:02:37 > 0:02:41It would be really exciting to see a house floating on water.
0:02:41 > 0:02:44Luke will be helping us. But standby, Neurons.
0:02:44 > 0:02:47I've a feeling I may need help from all of you.
0:02:47 > 0:02:51I need to get the workshop ready before the experimenters arrive.
0:02:53 > 0:02:56Sugar likes being the goalie when playing football.
0:02:56 > 0:02:59Poppy loves playing snakes and ladders.
0:02:59 > 0:03:04But they both want to know can we build floating houses?
0:03:04 > 0:03:10So, today, for one day only, Sugar and Poppy become the experimenters.
0:03:15 > 0:03:18- Hi, guys. BOTH:- Hi, Nina.
0:03:18 > 0:03:21Welcome, and thank you for your great question -
0:03:21 > 0:03:23can we build floating houses.
0:03:23 > 0:03:26This is what a floating house might look like.
0:03:26 > 0:03:30All houses on land have a base underneath called foundations
0:03:30 > 0:03:32to stop them sinking into the ground.
0:03:32 > 0:03:36And floating houses would also need foundations
0:03:36 > 0:03:38to stop them sinking into the water.
0:03:38 > 0:03:40But how would they work?
0:03:40 > 0:03:44Why don't we try building foundations for a floating house
0:03:44 > 0:03:46- to found out more? BOTH:- Yeah.
0:03:46 > 0:03:50- ALL:- Whoop-whoo! An experiment! We're ready, Nina.
0:03:50 > 0:03:53So, I've got a box here with five sides.
0:03:53 > 0:03:56I'm going to pop it into the water.
0:03:56 > 0:04:00And I want you guys to watch what happens.
0:04:03 > 0:04:05Hey, it's floating!
0:04:05 > 0:04:07Oh.
0:04:07 > 0:04:08Uh-oh.
0:04:08 > 0:04:10SHE CHUCKLES
0:04:10 > 0:04:13- What's happening, experimenters? - It's sinking.
0:04:13 > 0:04:16We wouldn't want our house to sink, Nina.
0:04:16 > 0:04:18Yes!
0:04:18 > 0:04:21The water is getting in through the joins.
0:04:21 > 0:04:24Oh, no. It's sinking.
0:04:24 > 0:04:27Having joins in the box meant that water got in.
0:04:27 > 0:04:29So, how could we make it better?
0:04:29 > 0:04:34- Have one with no joins. - Great idea. Let's try that.
0:04:34 > 0:04:37We've got some runny paste here that will go hard
0:04:37 > 0:04:40and we've got the mould in the shape of a box.
0:04:40 > 0:04:42So, let's pour our runny paste.
0:04:42 > 0:04:45That's it. Go for it.
0:04:45 > 0:04:46And stop.
0:04:46 > 0:04:48Oh, lovely. SHE CHUCKLES
0:04:50 > 0:04:52Ooooh!
0:04:52 > 0:04:56When it goes hard, the paste will stay in the shape of the box
0:04:56 > 0:04:58even when the mould's taken away.
0:05:02 > 0:05:05Oh! I think our foundations are ready now.
0:05:05 > 0:05:08Here we go.
0:05:08 > 0:05:09Ooh.
0:05:13 > 0:05:14SHE CHUCKLES
0:05:16 > 0:05:17There we go.
0:05:17 > 0:05:22I'm going to put this box into the water, just like the last one.
0:05:28 > 0:05:30SHE GASPS
0:05:30 > 0:05:32Hey!
0:05:32 > 0:05:34This box is floating, too.
0:05:34 > 0:05:36But is it leaking?
0:05:36 > 0:05:37- No.- No.
0:05:37 > 0:05:41That's right. This box looks the same as the other one,
0:05:41 > 0:05:42but what's different?
0:05:42 > 0:05:44- There are no joins.- That's right.
0:05:44 > 0:05:47Because the box has no joins, water can't get in.
0:05:47 > 0:05:51As long as there's no water in the box, it will keep floating.
0:05:51 > 0:05:55The foundations of a floating house could be made in the same way.
0:05:55 > 0:05:57Except from concrete.
0:05:57 > 0:06:01- How can concrete float? - Good question.
0:06:01 > 0:06:06Well, concrete IS very heavy. So, how can a concrete box float?
0:06:06 > 0:06:11Hm. I think we need to go somewhere with lots of big floats to find out.
0:06:16 > 0:06:19Off we go for another adventure.
0:06:19 > 0:06:22Maybe we're going to a swimming pool with lots of floats.
0:06:22 > 0:06:25Or we can make a splash-splash sound in the water.
0:06:25 > 0:06:29Or a big bathtub with lots of floating toys!
0:06:29 > 0:06:34Well, it's not a bathtub, but I CAN see lots of things floating.
0:06:47 > 0:06:50So, your question was, can we build floating houses?
0:06:50 > 0:06:53So far, we've discovered that floating houses
0:06:53 > 0:06:56are built on foundations made of moulded concrete.
0:06:56 > 0:07:00But now we want to know how heavy concrete can float.
0:07:00 > 0:07:03We've come here to Amsterdam in the Netherlands
0:07:03 > 0:07:06to have a look at these special houses.
0:07:06 > 0:07:08What do you notice about them?
0:07:08 > 0:07:12- They're floating.- Yes! This is a whole village of floating houses.
0:07:12 > 0:07:17Lots of people wanted to live here, but they ran out of land to build on.
0:07:17 > 0:07:20They built floating houses on the water instead.
0:07:20 > 0:07:21Shall we have a look around?
0:07:21 > 0:07:24- BOTH:- Yes! - Let's go.
0:07:41 > 0:07:44These houses are built on concrete foundations,
0:07:44 > 0:07:46like the floating house we made.
0:07:46 > 0:07:49But we want to know, how can heavy concrete float?
0:07:49 > 0:07:54So, let's do an experiment. OK, you both have balls of clay.
0:07:54 > 0:07:56They're both the same weight.
0:07:56 > 0:07:59- So, do you think they'll float? - No, Nina.
0:07:59 > 0:08:02Why don't you try this one, Sugar?
0:08:02 > 0:08:03Oh.
0:08:03 > 0:08:07You were absolutely right. It's sunk to the bottom.
0:08:07 > 0:08:11What do you think we could do with this other ball to make it float?
0:08:11 > 0:08:14- Spread it out. - That's a really good idea.
0:08:14 > 0:08:19So, can you flatten it out for me and then make it into a cup shape?
0:08:19 > 0:08:20On you go, Poppy.
0:08:26 > 0:08:28OK, that's looking really good.
0:08:28 > 0:08:31Why don't you try popping it onto the water?
0:08:33 > 0:08:37Hey, hey, look at that! It's floating!
0:08:38 > 0:08:42So, even though they both weigh the same, the cup shape is floating
0:08:42 > 0:08:46because the weight is spread out so it takes up more space.
0:08:46 > 0:08:50The ball, its weight is tightly packed together, so it sunk.
0:08:50 > 0:08:54And when something is packed together tightly, we call it dense.
0:08:54 > 0:08:59Mm, so "dense" means "packed close together".
0:08:59 > 0:09:02Everything has a density. Even water.
0:09:02 > 0:09:06So, the ball is denser than the water, so it sank.
0:09:06 > 0:09:10But because we spread this ball out into a cup shape,
0:09:10 > 0:09:13it was less dense than the water, so it floated.
0:09:13 > 0:09:16Really heavy things like concrete can float
0:09:16 > 0:09:19as long as their weight is spread out over enough space.
0:09:19 > 0:09:24- Does a floating house move about in the water?- Great question, Sugar.
0:09:24 > 0:09:27Let's do one final experiment to find out.
0:09:29 > 0:09:32So, you asked, can we build floating houses?
0:09:32 > 0:09:36But now we want to know if floating houses will move about.
0:09:36 > 0:09:39So, have a look at this boat over here.
0:09:39 > 0:09:42So, can you see why it doesn't float away?
0:09:42 > 0:09:47- It's tied up.- Yes, it's tied up to a pole that can't move.
0:09:47 > 0:09:52- Floating houses are tied up, too, so they don't float away.- Oh, phew!
0:09:52 > 0:09:54Let's have another look at the boat.
0:09:54 > 0:09:59- Can you see how it's bobbing up and down in the water?- Yes, Nina.
0:09:59 > 0:10:00It wouldn't be much fun
0:10:00 > 0:10:04if your floating house was bobbing up and down all the time.
0:10:04 > 0:10:05You'd get seasick.
0:10:05 > 0:10:09But floating houses are tied up in a clever way so they don't move about.
0:10:09 > 0:10:11So, let's investigate.
0:10:11 > 0:10:14We've got two floating houses here
0:10:14 > 0:10:17and we need to get them tied up before they float away.
0:10:17 > 0:10:21Now, Sugar, in your tray, you've got two poles on one side.
0:10:21 > 0:10:25And, Poppy, you've got two posts on the opposite sides.
0:10:25 > 0:10:28All right, so let's get them tied up.
0:10:32 > 0:10:33Excellent work, guys.
0:10:35 > 0:10:37- Ta-da!- Great work, experimenters.
0:10:37 > 0:10:41You've tied up the floating houses so they won't float away.
0:10:41 > 0:10:45Which one is nicer to live in? Let's make some waves to find out.
0:10:45 > 0:10:48You can make the waves using these pieces of card.
0:10:56 > 0:10:59OK, experimenters, stop there.
0:10:59 > 0:11:02Sugar, what happened to your floating house?
0:11:02 > 0:11:04It bobbed up and down.
0:11:04 > 0:11:08- It WAS bobbing up and down. What about yours, Poppy?- It didn't move.
0:11:08 > 0:11:11It didn't move, and that is because, Sugar,
0:11:11 > 0:11:14your house was only tied up on one side,
0:11:14 > 0:11:17so the waves could easily push it up and down.
0:11:17 > 0:11:20And, Poppy, your house was tied up on opposite corners.
0:11:20 > 0:11:25That stopped it moving up and down with the waves and held it still.
0:11:25 > 0:11:28Which floating house would it be nicer to live in?
0:11:29 > 0:11:31I think so, too.
0:11:31 > 0:11:35So, floating houses are tied up at the opposite corners just like this.
0:11:35 > 0:11:38That stops them bobbing about in the water
0:11:38 > 0:11:41so the people inside don't get seasick.
0:11:41 > 0:11:44# Nina and the neurons! #
0:11:45 > 0:11:48So, your question was, can we build floating houses?
0:11:48 > 0:11:50I think we've answered it.
0:11:50 > 0:11:56Floating houses need foundations to stop them sinking into the water.
0:11:56 > 0:11:59The foundations can be made by moulding concrete.
0:11:59 > 0:12:03They're spread out so they're less dense than water.
0:12:03 > 0:12:07Floating houses are tied to poles to stop them floating away.
0:12:07 > 0:12:11Tying the houses in opposite corners stops them bobbing up and down.
0:12:11 > 0:12:16- I hope that's answered your question. BOTH:- Thanks, Nina. Bye.
0:12:16 > 0:12:18Oh, you're welcome. Bye.
0:12:21 > 0:12:25If you want to know more about the science that's all around us,
0:12:25 > 0:12:28go to the Nina section on the CBeebies website.
0:12:28 > 0:12:30# Superstructures
0:12:30 > 0:12:31# Superstructures
0:12:31 > 0:12:36# Superstructures, superstructures Superstructures
0:12:36 > 0:12:39# Some of them are tall Some of them are wide
0:12:39 > 0:12:42# They're bumpy, lumpy, wiggley-tee
0:12:42 > 0:12:44# Wiggley-tee
0:12:44 > 0:12:48- # Some of them are strong Some of them are small- Like me!
0:12:48 > 0:12:50# They're windy, whirly, whooshy, too
0:12:50 > 0:12:52# All around
0:12:52 > 0:12:54# Look over here
0:12:54 > 0:12:57# Build it, stack it, pile it up
0:12:57 > 0:13:00# Come on, let's get building
0:13:00 > 0:13:02# Building, building, building
0:13:02 > 0:13:06# Race it, hold it, make it stick
0:13:06 > 0:13:09# Come on, let's get building
0:13:09 > 0:13:13# Come on Let's get building
0:13:15 > 0:13:19# Some of them are cosy-warm Some of them are chilly
0:13:19 > 0:13:24- # Keep us safe and hide us, too - Hide us, too
0:13:24 > 0:13:27# Some of them are just for fun or help us to stay dry
0:13:27 > 0:13:30# They're underground and high up, too
0:13:30 > 0:13:32# Look around
0:13:32 > 0:13:34# Over here
0:13:34 > 0:13:37# Build it, stack it, pile it up
0:13:37 > 0:13:42- # Come on, let's get building. - Building- Building- Building
0:13:42 > 0:13:46# Race it, hold it, make it stick
0:13:46 > 0:13:49# Come on, let's get building
0:13:49 > 0:13:53# Come on, let's get building! #
0:13:54 > 0:13:57There are superstructures everywhere.
0:13:57 > 0:14:02Whether they're big or small, wide or tall, you can all get building.
0:14:02 > 0:14:04See you again soon. Bye!
0:14:04 > 0:14:07- ALL:- Bye! - Get building!