0:00:05 > 0:00:08# If you've got a question and you don't know where to go
0:00:08 > 0:00:12# Ask Nina for some help, she's got a science show
0:00:12 > 0:00:14# She makes sense of her senses 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 > 0:00:21- # Fingers - Fingers!
0:00:21 > 0:00:23- # Eyes.- Eyes! - Ears.- Ears!- Nose.- Nose!
0:00:23 > 0:00:29# Every day we use our senses Wherever we may go
0:00:29 > 0:00:31- # Tongue - Tongue!
0:00:31 > 0:00:32- # Fingers - Fingers!
0:00:32 > 0:00:36- # Eyes.- Eyes! - Ears.- Ears!- Nose.- Nose!
0:00:36 > 0:00:39# Nina and the Neurons find out what you need to know
0:00:39 > 0:00:41# Nina and the Neurons find out what you need to know
0:00:41 > 0:00:44# Luke, he helps us with our eyes and Felix with our touch
0:00:44 > 0:00:47# Ollie sniffs out smells And Belle, she hears so much
0:00:47 > 0:00:50# Bud is Ollie's brother, he helps us with our taste
0:00:50 > 0:00:53# They're Nina's little neurons And they're coming to your place!
0:00:53 > 0:00:55- # Touch your tongue - Tongue!
0:00:55 > 0:00:56- # Fingers - Fingers!
0:00:56 > 0:01:00- # Eyes.- Eyes! - Ears.- Ears!- Nose.- Nose!
0:01:00 > 0:01:02# Nina and the Neurons find out what you need to know
0:01:02 > 0:01:05# Nina and the Neurons find out what you need to know
0:01:05 > 0:01:07# Oh yeah! #
0:01:08 > 0:01:11- Hi, everyone!- ALL: Hi, Nina!
0:01:11 > 0:01:14I've got an interesting experiment to show you,
0:01:14 > 0:01:16involving these three beakers.
0:01:16 > 0:01:19In here is honey,
0:01:19 > 0:01:21in here is water,
0:01:21 > 0:01:23and this one is olive oil.
0:01:23 > 0:01:26First I'll pop in the olive oil.
0:01:32 > 0:01:34Now the water.
0:01:34 > 0:01:37Oooh! What a nice colour that's making.
0:01:37 > 0:01:39And now the honey.
0:01:44 > 0:01:47Oh, fantastic.
0:01:47 > 0:01:49Let's take a closer look here.
0:01:49 > 0:01:53They're not mixing together, look! Here's the oil,
0:01:53 > 0:01:57the water's in the middle and the honey's at the bottom
0:01:57 > 0:02:00so they're all floating on top of one another.
0:02:00 > 0:02:04I've three different balls here. It might be fun
0:02:04 > 0:02:08if you try and guess if each of these will sink or float.
0:02:08 > 0:02:13So let's start with the ping-pong ball.
0:02:13 > 0:02:14THEY SHOUT DIFFERENT THINGS
0:02:14 > 0:02:16Let's see.
0:02:18 > 0:02:19< See!
0:02:19 > 0:02:21Oh! Well, I don't know about you,
0:02:21 > 0:02:24but I'd say that's definitely floating.
0:02:24 > 0:02:26The next ball...
0:02:26 > 0:02:29is a glass ball.
0:02:29 > 0:02:31- THEY SHOUT OUT - Sink?!
0:02:31 > 0:02:33Well, let's see.
0:02:33 > 0:02:35Oh!
0:02:35 > 0:02:37It made a right good plop.
0:02:37 > 0:02:39Your guesses are getting good.
0:02:39 > 0:02:43This is a bouncy ball, so what do you think?
0:02:43 > 0:02:44THEY SHOUT
0:02:44 > 0:02:48If you're not sure, the best thing to do is to try and see.
0:02:48 > 0:02:49Here we go.
0:02:49 > 0:02:51THEY SHOUT
0:02:51 > 0:02:54Now, this is a bit different, look.
0:02:54 > 0:02:58The ball has sunk to the bottom of the water, not through the honey.
0:02:58 > 0:03:03Well, the reason that things float or sink is to do with something
0:03:03 > 0:03:04called density.
0:03:04 > 0:03:07Let's have a look at these three balls.
0:03:07 > 0:03:11They're almost the same size, but the glass ball is much heavier
0:03:11 > 0:03:13as it has a greater density.
0:03:13 > 0:03:15That's the same with liquids.
0:03:15 > 0:03:21Honey has more density than water, and water has more density than oil.
0:03:21 > 0:03:23Everything has density, even you and me.
0:03:23 > 0:03:26APPLAUSE
0:03:26 > 0:03:28BLEEPING
0:03:28 > 0:03:33I hear a beep, I see a flash. I wonder what they're going to ask.
0:03:37 > 0:03:40Hi, Nina, I'm Aman. I've got a question for you.
0:03:40 > 0:03:45Why does my mum tell me to turn off the tap when I'm brushing my teeth?
0:03:45 > 0:03:47That's a great question, Aman.
0:03:47 > 0:03:50We're going to have fun finding this out.
0:03:50 > 0:03:55- I'll be round soon to help answer your question.- Thanks, Nina. Bye.
0:03:55 > 0:03:56Bye!
0:03:57 > 0:04:01I'm going to need help to answer this one, and I know who to ask.
0:04:01 > 0:04:04OK, neurons, time to get to work!
0:04:19 > 0:04:21ALL: Neurons at the ready, Nina!
0:04:21 > 0:04:26OK, today's question is, why does my mum tell me to turn the tap off
0:04:26 > 0:04:28when I'm brushing my teeth.
0:04:28 > 0:04:31Which neuron will be most useful in finding the answer?
0:04:31 > 0:04:35ALL: Me! Me! Me!
0:04:35 > 0:04:36Will it be fabulous Felix?
0:04:36 > 0:04:41I can help so very much, if you need the sense of touch.
0:04:41 > 0:04:43Will it be beautiful Belle?
0:04:43 > 0:04:45I send messages to brain from ear.
0:04:45 > 0:04:48if there's a sound, I'll help you hear.
0:04:48 > 0:04:49Will it be lovely Luke?
0:04:49 > 0:04:52For looking and seeing, day or night,
0:04:52 > 0:04:54I'll help you with your sense of sight.
0:04:54 > 0:04:56Will it be awesome Ollie?
0:04:56 > 0:04:59If it's pongy or whiffy, but you can't tell,
0:04:59 > 0:05:02my messages help your sense of smell.
0:05:02 > 0:05:03Or will it be baby Bud?
0:05:03 > 0:05:05Sour, salty, bitter or sweet,
0:05:05 > 0:05:08I'm your taste buddy whenever you eat.
0:05:12 > 0:05:14- It's Luke!- Yes!
0:05:14 > 0:05:17ALL: Go Luke! Go Luke! Go Luke!
0:05:17 > 0:05:20Go Luke! Go Luke! Go Luke!
0:05:20 > 0:05:21Go Luke!
0:05:21 > 0:05:25Cool, Nina. I'll be looking out to help ya.
0:05:25 > 0:05:26Thanks, Luke.
0:05:26 > 0:05:30Today's question is, why does my mum tell me to turn the tap off
0:05:30 > 0:05:32when I'm brushing my teeth.
0:05:32 > 0:05:37We're going to a lot of looking about, so Luke's going to be busy.
0:05:37 > 0:05:41Stand by, neurons, I think I might need help from all of you today.
0:05:41 > 0:05:44OK. Let's go!
0:06:01 > 0:06:03Aman's question is about water.
0:06:03 > 0:06:05Dripping water, sloshing water,
0:06:05 > 0:06:08running, flowing and splashing water.
0:06:08 > 0:06:10So today, for one day only,
0:06:10 > 0:06:14Aman and his cousin Elina become The Experimenters!
0:06:16 > 0:06:17Hello, guys.
0:06:17 > 0:06:19Hi, Nina!
0:06:19 > 0:06:23Aman, your question is, why does my mum tell me to turn the tap off
0:06:23 > 0:06:27when I'm brushing my teeth. Why do you want to know that?
0:06:27 > 0:06:32Because my mum says that I shouldn't waste water, but I don't know why.
0:06:32 > 0:06:36Well, Aman, mums usually know best.
0:06:36 > 0:06:40To answer your question, I think we need to investigate further.
0:06:40 > 0:06:42I know just the place to start.
0:06:42 > 0:06:44Luke, are you standing by to help?
0:06:44 > 0:06:48- At your service, Nina. - Excellent. Let's go.
0:06:48 > 0:06:51OK, I've brought you to a reservoir.
0:06:51 > 0:06:53What is a reservoir for?
0:06:53 > 0:06:55- Fishing?- Sailing?
0:06:55 > 0:06:57Feeding the ducks?
0:06:57 > 0:07:00You could do those things in some reservoirs.
0:07:00 > 0:07:02But it's not their main purpose.
0:07:02 > 0:07:05A reservoir is a special loch that collects water.
0:07:05 > 0:07:09When it rains, the reservoir fills up with water,
0:07:09 > 0:07:14- and the water travels through lots of pipes to people's houses.- Wow!
0:07:14 > 0:07:17That sounds like miles and miles of pipes.
0:07:17 > 0:07:20I can't see any pipes, Nina!
0:07:20 > 0:07:24The reason we can't see any pipes is because they're underground.
0:07:24 > 0:07:28Now, let me try something. Stay there.
0:07:32 > 0:07:35I just collected water from the reservoir.
0:07:35 > 0:07:37Would you like a drink of water?
0:07:37 > 0:07:39No, yuck!
0:07:39 > 0:07:41Why not? What's wrong with it?
0:07:41 > 0:07:45- It's all mucky. - It's got bits floating in it.
0:07:45 > 0:07:46Yes, you're right.
0:07:46 > 0:07:51Birds and fish have been swimming in it, plants have been growing in it,
0:07:51 > 0:07:55insects and leaves have been falling into it. It's not very clean.
0:07:55 > 0:07:57But don't worry. I have an idea.
0:07:57 > 0:08:00I need some things for an experiment.
0:08:00 > 0:08:02This glass...
0:08:03 > 0:08:07..this plastic bottle with the bottom cut off...
0:08:08 > 0:08:11..and some cotton wool.
0:08:11 > 0:08:14I'll sit this cotton wool in the neck of the bottle.
0:08:14 > 0:08:19But there are still some things missing to make the experiment work.
0:08:19 > 0:08:22We need big stones, little stones and some sand.
0:08:22 > 0:08:25Let's see if we can find them here.
0:08:28 > 0:08:31That's the sand, now some smaller stones.
0:08:35 > 0:08:36Oooh!
0:08:36 > 0:08:39Oh, nice size, perfect.
0:08:41 > 0:08:43Let's whop that in there.
0:08:43 > 0:08:47Now I'll pour the water from the reservoir into the bottle.
0:08:47 > 0:08:52Aman, can you hold the glass steady for me. Thank you.
0:08:52 > 0:08:54Here we go.
0:08:55 > 0:08:58Whoa, oh, some twigs there.
0:08:58 > 0:09:01Now, let's watch closely.
0:09:01 > 0:09:03Oh, it's coming!
0:09:03 > 0:09:05It's coming out the bottom!
0:09:05 > 0:09:07Oh, there's lots of twigs!
0:09:07 > 0:09:09Wow, look at the water.
0:09:09 > 0:09:12- It's much cleaner.- That's right.
0:09:12 > 0:09:15It's because the layers trap the bits
0:09:15 > 0:09:17that were floating in the water.
0:09:17 > 0:09:18It's called a filter.
0:09:18 > 0:09:21So would you like to drink it now?
0:09:21 > 0:09:24- No.- No.- Neither would I! The bits have gone,
0:09:24 > 0:09:26but it's not completely clear.
0:09:26 > 0:09:29There might be germs in there that we can't see.
0:09:29 > 0:09:34Before reservoir water is safe to drink, the germs must be taken out.
0:09:34 > 0:09:37That happens at a water treatment plant.
0:09:37 > 0:09:39- Would you like to visit one?- Yes!
0:09:39 > 0:09:41Brilliant! Let's go.
0:09:43 > 0:09:48This is the big pipe where the water comes in from the reservoir.
0:09:48 > 0:09:52This huge filter cleans the reservoir water.
0:09:52 > 0:09:54It's just like the filter we made.
0:09:54 > 0:09:56What's happening now?
0:09:56 > 0:10:01That's the dirty floating bits all being washed away.
0:10:01 > 0:10:05This is where the water's cleaned a bit more
0:10:05 > 0:10:07and all the germs are removed.
0:10:07 > 0:10:11Then the water travels through lots of pipes
0:10:11 > 0:10:15to get to people's houses like those over there.
0:10:15 > 0:10:20As you can see, cleaning the water takes a lot of time and energy.
0:10:20 > 0:10:23So, now we know where our water comes from
0:10:23 > 0:10:25and how it gets to our houses.
0:10:25 > 0:10:29- But we still haven't answered your question, have we?- No.
0:10:29 > 0:10:33Why does my mum tell me to turn the tap off when I'm brushing my teeth?
0:10:33 > 0:10:36I've got an idea! Come on, this way!
0:10:38 > 0:10:40OK, your mum must have a good reason
0:10:40 > 0:10:44for telling you to turn the tap off when you brush your teeth.
0:10:44 > 0:10:47so we'll do an experiment to find out why.
0:10:47 > 0:10:50You'll brush your teeth for two minutes.
0:10:50 > 0:10:55Aman, you brush your teeth in that sink with the tap running.
0:10:55 > 0:11:00Elina, you brush your teeth in this sink without the tap running.
0:11:00 > 0:11:04At the start you can wet your brush and rinse it at the end.
0:11:04 > 0:11:06- Are you happy?- Yes, Nina.
0:11:06 > 0:11:08OK, let me get my stopwatch.
0:11:08 > 0:11:12So are you ready...steady...go!
0:11:20 > 0:11:23I like the feel of a bristly toothbrush,
0:11:23 > 0:11:28- hard at work. - Yeah! Brushing teeth is great!
0:11:28 > 0:11:31It tastes all cool and fresh.
0:11:31 > 0:11:33And smells minty too.
0:11:33 > 0:11:37Listen to all that water splishing and splashing.
0:11:37 > 0:11:40Oh, I just love that sound.
0:11:40 > 0:11:41Time's up!
0:11:41 > 0:11:43And stop.
0:11:43 > 0:11:45So rinse your toothbrushes.
0:11:47 > 0:11:52OK, so Aman you've used six litres of water, isn't that amazing?
0:11:52 > 0:11:56Elina, you've only used a tiny bit. What a difference!
0:11:56 > 0:11:58Let me see your teeth.
0:11:58 > 0:12:00Very good job. Nice and clean.
0:12:00 > 0:12:04Aman, your teeth don't look any cleaner than Elina's
0:12:04 > 0:12:08- did you need all that water to brush your teeth?- No, Nina.
0:12:08 > 0:12:12Hmm, I think we've just answered your question.
0:12:13 > 0:12:15OK, Aman, your question was
0:12:15 > 0:12:20why does my mum tell me to turn the tap off when I'm brushing my teeth?
0:12:20 > 0:12:24Firstly we discovered that our tap water comes from reservoirs
0:12:24 > 0:12:29far away from our homes and we found out that water needs to be cleaned,
0:12:29 > 0:12:32and that takes a lot of time and energy.
0:12:32 > 0:12:35If you don't turn the tap off you waste lots of
0:12:35 > 0:12:38precious, delicious, lovely clean water.
0:12:38 > 0:12:41It'll just run down the plughole.
0:12:41 > 0:12:45That's right. If you do turn the tap off, you're saving water
0:12:45 > 0:12:48which saves energy and that helps protect the planet.
0:12:48 > 0:12:50Thanks, Nina!
0:12:50 > 0:12:53- Bye, guys!- Bye, Nina!
0:12:57 > 0:13:00# Help protect our planet
0:13:00 > 0:13:03- # Go eco,- Go eco!
0:13:03 > 0:13:06# Walk to school or cycle
0:13:06 > 0:13:09- # Go eco,- Go eco!
0:13:09 > 0:13:13# Turn off the tap, switch off the light
0:13:13 > 0:13:16# Recycle what you can
0:13:16 > 0:13:18# Help protect our planet
0:13:18 > 0:13:21- # Go eco,- Go eco!
0:13:21 > 0:13:23# Go eco! #
0:13:23 > 0:13:26Ah, it's been such a great day, man,
0:13:26 > 0:13:31looking at that lovely reservoir filled with beautiful cool water.
0:13:31 > 0:13:34It's been a marvellous day.
0:13:34 > 0:13:38It was so interesting watching them make a water filter.
0:13:38 > 0:13:40Oh, I've had a brilliant day,
0:13:40 > 0:13:46hearing all that splishing and splashing, I love the sound of water.
0:13:46 > 0:13:48I've had a fabby day,
0:13:48 > 0:13:51brushing teeth is great fun!
0:13:51 > 0:13:53I've really enjoyed myself today,
0:13:53 > 0:13:58there were so many minty smells when they brushed their teeth.
0:13:58 > 0:14:02We've had a sensational time. I hope you enjoyed it too.
0:14:02 > 0:14:03See you again soon! Bye!
0:14:03 > 0:14:05Bye!
0:14:05 > 0:14:07Subtitles by Red Bee Media Ltd
0:14:07 > 0:14:10E-mail subtitling@bbc.co.uk