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 > 0:00:23- # 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 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 > 0:00:47- # Eyes!- Eyes! - Ears!- Ears!- Nose!- Nose!
0:00:47 > 0:00:50# Nina and the Neurons find out what you need to know
0:00:50 > 0:00:53# Nina and the Neurons find out what you need to know
0:00:53 > 0:00:54# Oh, yeah! #
0:00:59 > 0:01:02Oh, hello. I'm just blowing up some balloons.
0:01:02 > 0:01:05You never know when you might need one for an experiment!
0:01:10 > 0:01:13I'm a bit out of breath after all of that.
0:01:13 > 0:01:18I hear a beep, I see a flash, I wonder what they're going to ask.
0:01:24 > 0:01:28- Hi, Nina.- Hi, guys. - We've got a question for you.
0:01:28 > 0:01:32- How does a hot-air balloon fly? - That's a great question.
0:01:32 > 0:01:36How does a hot-air balloon fly? It takes some very clever engineering.
0:01:36 > 0:01:39Come to my workshop and we'll investigate.
0:01:39 > 0:01:42See you soon, Nina. Bye.
0:01:42 > 0:01:46Bye. Well, I'm going to need some help to answer this one
0:01:46 > 0:01:48and I know just who to ask.
0:01:48 > 0:01:50OK, Neurons, time to get to work.
0:02:05 > 0:02:08ALL: Neurons at the ready, Nina!
0:02:08 > 0:02:12OK, today's question is how does a hot-air balloon fly?
0:02:12 > 0:02:16Which neuron would be most useful to help us find the answer?
0:02:16 > 0:02:19- Me!- Me!- Me!- Oh, me!
0:02:19 > 0:02:22Will it be fabulous Felix?
0:02:22 > 0:02:26I can help so very much, if you need the sense of touch.
0:02:26 > 0:02:28Will it be beautiful Belle?
0:02:28 > 0:02:30I send messages to brain from ear,
0:02:30 > 0:02:32if there's a sound I'll help you hear.
0:02:32 > 0:02:34Will it be lovely Luke?
0:02:34 > 0:02:36Looking and seeing day or night,
0:02:36 > 0:02:39I'll help you with your sense of sight.
0:02:39 > 0:02:41Will it be awesome Ollie?
0:02:41 > 0:02:43If it's pongy or whiffy, but you can't tell,
0:02:43 > 0:02:46my messages help your sense of smell.
0:02:46 > 0:02:47Or will it be baby Bud?
0:02:47 > 0:02:53Sour, salty, bitter or sweet, I'm your taste buddy whenever you eat.
0:02:53 > 0:02:55COMPUTER BLEEPS
0:02:57 > 0:02:59It's Luke!
0:02:59 > 0:03:05NEURONS: Go Luke! Go Luke! Go Luke! Go Luke! Go Luke! Go Luke!
0:03:07 > 0:03:10Cool, Nina. I'll be looking out to help ya!
0:03:10 > 0:03:13Today's question is how does a hot-air balloon fly?
0:03:13 > 0:03:16As a hot-air balloon is something we can see,
0:03:16 > 0:03:18Luke'll be helping us.
0:03:18 > 0:03:22Stand by, Neurons, I've a feeling I may need help from you all.
0:03:22 > 0:03:27Right, I need to get the workshop ready before the engineers arrive.
0:03:28 > 0:03:32Sydney loves monkey bars. Thomas loves riding his bike.
0:03:32 > 0:03:34Amy likes walking in the woods.
0:03:34 > 0:03:37I saw a hot-air balloon flying in the sky.
0:03:37 > 0:03:41- A normal balloon doesn't fly.- A hot-air balloon doesn't have wings.
0:03:41 > 0:03:47So today, for one day only, Sydney, Amy and Thomas become the engineers.
0:03:51 > 0:03:53- Hi, guys!- ALL: Hi, Nina.
0:03:53 > 0:03:57Welcome to my workshop and thanks for your question -
0:03:57 > 0:03:59"How does a hot-air balloon fly?"
0:03:59 > 0:04:03To find out the answer, let's start by using our senses.
0:04:03 > 0:04:07NEURONS: Woop-woo! A senses experiment! We're ready, Nina.
0:04:07 > 0:04:12First, let's take a look at a hot-air balloon in action.
0:04:12 > 0:04:16LUKE: Whoa, look at that colourful, big balloon flying in the sky.
0:04:16 > 0:04:18Beautiful!
0:04:18 > 0:04:23- BUD:- Oh, it's got a giant picnic basket underneath!
0:04:23 > 0:04:26It's not a picnic basket, Bud!
0:04:26 > 0:04:28That's the basket for the people.
0:04:28 > 0:04:33So, we know that a hot-air balloon can fly, but how does it do it?
0:04:33 > 0:04:37To find out, we need to know a bit more about air.
0:04:37 > 0:04:42Air is all around us, but we just can't see it. It's even in this bag.
0:04:42 > 0:04:45Woo-woo-woo!
0:04:45 > 0:04:49Just like it is in a normal balloon that you'd have at a party.
0:04:49 > 0:04:54- So what do you think will happen if I let it go?- It'll fall.
0:04:54 > 0:04:56Well, let's see.
0:04:56 > 0:05:02Oh, you were right. When I let go of the bag, it fell.
0:05:02 > 0:05:06It's the same as the balloons we blow up at home. They don't lift up.
0:05:06 > 0:05:11But let's see what happens if we make the air inside a bag hot
0:05:11 > 0:05:14using my very own special air heater.
0:05:14 > 0:05:17Remember, hot things are dangerous
0:05:17 > 0:05:19so you should never try this at home.
0:05:21 > 0:05:25MACHINE WHIRRS
0:05:29 > 0:05:33There should be plenty of hot air in there now.
0:05:35 > 0:05:36Whoo, ah!
0:05:38 > 0:05:40So, what happened?
0:05:40 > 0:05:42It floated up.
0:05:42 > 0:05:47Yes, it floated up, and that is because hot air rises up the way.
0:05:47 > 0:05:50When we heated the air inside the bag,
0:05:50 > 0:05:53the hot air rose up and it lifted the bag up with it.
0:05:53 > 0:05:57But when we weren't, the air inside the bag cooled down.
0:05:57 > 0:06:00And as the hot air cooled, the bag came down.
0:06:00 > 0:06:03What goes up, must come down.
0:06:03 > 0:06:07So, from our experiment, we found out that hot air rises,
0:06:07 > 0:06:10whereas cold or normal air sinks.
0:06:10 > 0:06:14But that was just a light bag with a little bit of hot air in it.
0:06:14 > 0:06:17I wonder what would happen if we heated lots of air.
0:06:17 > 0:06:19Let's find out!
0:06:22 > 0:06:26Here we go! I can't wait to see where we'll end up today!
0:06:26 > 0:06:30- BELLE:- Nina said it was somewhere with lots of air.
0:06:30 > 0:06:35Maybe it's somewhere really windy! Whoosh!
0:06:35 > 0:06:38We're about to find out, we're here!
0:06:38 > 0:06:42These are hot-air balloons and they are full of hot air.
0:06:42 > 0:06:45They're much bigger than our bag.
0:06:45 > 0:06:48Let's go and take a closer look at one!
0:06:58 > 0:07:02Brilliant, the fan has filled all of the balloon with air.
0:07:02 > 0:07:05- But it's quite cool air, isn't it? - Yes, it is.
0:07:05 > 0:07:08So, now it is time to heat up the air,
0:07:08 > 0:07:10just like we did with our bag.
0:07:10 > 0:07:13So, let's go outside and see how they do it.
0:07:14 > 0:07:18Look, as the burners are heating the air, the air is rising
0:07:18 > 0:07:22and pushing the balloon up. Just like earlier with our bag.
0:07:22 > 0:07:26But you know, I don't think we can see very well from here.
0:07:26 > 0:07:29We need to get in the balloon. What do you think?
0:07:29 > 0:07:31- ALL: Yeah!- Hee-hee-hee, let's go!
0:07:31 > 0:07:33LUKE: Hurry up, Nina.
0:07:33 > 0:07:37You don't want to miss the boat, or should I say basket?
0:07:37 > 0:07:40Oh, this balloon is really big.
0:07:40 > 0:07:44- Do you think it's big enough to lift us up?- Yeah!- Well, let's see.
0:07:44 > 0:07:49Can you loosen the ropes for us, please? Here goes!
0:07:52 > 0:07:54Yay, it's lifting us up.
0:07:54 > 0:07:57Engineers discovered that if we heat more air,
0:07:57 > 0:08:00it can lift bigger things, like us.
0:08:00 > 0:08:04What do you think will happen as the air starts to cool?
0:08:04 > 0:08:06We'll go down.
0:08:06 > 0:08:08Well, let's see.
0:08:08 > 0:08:13Oh, yes. Ha-ha-ha! Just like that.
0:08:13 > 0:08:16- Shall we do it one more time?- Yeah!
0:08:16 > 0:08:18OK, hot air up!
0:08:22 > 0:08:23Cool air...
0:08:23 > 0:08:26- ALL: Down!- Hee-hee!
0:08:26 > 0:08:31So, now we know how engineers make balloons fly using hot air!
0:08:31 > 0:08:34But we still don't know why hot air rises.
0:08:34 > 0:08:38I think we need to go back to the workshop to find out.
0:08:38 > 0:08:42So, your question was - "How does a hot-air balloon fly?"
0:08:42 > 0:08:47So far we've discovered that hot air rises and cool air sinks.
0:08:47 > 0:08:49Now, we want to know why hot air rises?
0:08:49 > 0:08:52It's time for one final experiment!
0:08:52 > 0:08:56So we want to know what happens to air when it gets hotter.
0:08:56 > 0:09:00I'm going to put this bottle into some warm water.
0:09:00 > 0:09:04And I've put some marbles in it, just to weigh the bottle down.
0:09:04 > 0:09:09And watch what happens to the balloon on top.
0:09:09 > 0:09:12FELIX: Remember, it's important not to touch hot water
0:09:12 > 0:09:14or it could burn you.
0:09:16 > 0:09:20- What's happened? - The balloon's blowing up.
0:09:20 > 0:09:24Yes, as the air in the bottle heats up, it takes up more space
0:09:24 > 0:09:26and blows up the balloon.
0:09:26 > 0:09:31We haven't added any more air, the air gets warm and expands,
0:09:31 > 0:09:34which means it takes up more space.
0:09:34 > 0:09:37Hey, I can expand too, when I do this.
0:09:37 > 0:09:40Whoa, I'm taking up more space!
0:09:40 > 0:09:42That's right, Bud.
0:09:42 > 0:09:45Air is a bit like a ball of cotton wool.
0:09:45 > 0:09:49When it heats up, it expands and takes up more space.
0:09:49 > 0:09:56So, if we all pick up our cotton wool and gently pull it like this.
0:09:57 > 0:10:01It's the same amount, it just takes up more space.
0:10:01 > 0:10:06So now let's see what happens if I put the bottle into the cold water.
0:10:14 > 0:10:16Oh!
0:10:16 > 0:10:18The balloon's gone down.
0:10:18 > 0:10:22Yes. If we cool the air, it takes up less space,
0:10:22 > 0:10:26just like if we squash our cotton wool back into a ball.
0:10:28 > 0:10:31So we know that hot air takes up more space,
0:10:31 > 0:10:35but we still don't know why hot air rises. Come with me.
0:10:37 > 0:10:41We're going to pretend that all these balls are air.
0:10:41 > 0:10:46The blue balls are cold air, because they take up less space.
0:10:46 > 0:10:48And the red balls are hot air,
0:10:48 > 0:10:52because they've expanded and take up more space.
0:10:52 > 0:10:54I'll pop those back in here.
0:10:54 > 0:10:57So, we've got lots of hot and cold air mixed up together.
0:10:57 > 0:11:02Let's see what happens if we move our hot and cold air balls about.
0:11:02 > 0:11:06Amy, could you give it a good mix and a shake for me, please?
0:11:06 > 0:11:09That's it. Get your hands right in there. Good girl!
0:11:09 > 0:11:14LUKE: Those big red balls are pushing their way to the top.
0:11:15 > 0:11:19Wow, the hot air balls gradually lifted to the top
0:11:19 > 0:11:23and the cold air balls settled on the bottom.
0:11:23 > 0:11:28And this shows us what happens with hot and cold air. The hot air rises.
0:11:28 > 0:11:33That's because hot air is lighter than the colder air around it.
0:11:33 > 0:11:35# Nina and the Neurons! #
0:11:37 > 0:11:40Your question was, "How does a hot-air balloon fly?"
0:11:40 > 0:11:42And I think we've answered it.
0:11:42 > 0:11:48We discovered that hot air rises and cold or normal air sinks.
0:11:48 > 0:11:51A hot-air balloon is filled with lots of air which is then heated
0:11:51 > 0:11:55and the hot air lifts up the balloon.
0:11:55 > 0:11:58To come down again, you let the air cool.
0:11:58 > 0:12:03Hot air rises because it expands and is lighter than the air around it.
0:12:03 > 0:12:07And if you have enough hot air, you can lift a big balloon,
0:12:07 > 0:12:10and even people, up into the sky.
0:12:10 > 0:12:13Just like us in our very own hot-air balloon.
0:12:13 > 0:12:17- I hope that answered your question. - Thanks, Nina. Bye.
0:12:17 > 0:12:20You're welcome. Bye.
0:12:20 > 0:12:24If you want to know more about the science and engineering
0:12:24 > 0:12:29that's all around us, go to the Nina section on the CBeebies website.
0:12:29 > 0:12:30Have fun!
0:12:30 > 0:12:33- Pulling!- Pushing!- Twisting!- Mixing! - Squeezing!- Floating!
0:12:33 > 0:12:35# Go engineering!
0:12:35 > 0:12:38# Go engineering!
0:12:39 > 0:12:42# When we need to fly it, make it, shape it
0:12:43 > 0:12:45# Go engineering!
0:12:45 > 0:12:48# Go engineering!
0:12:48 > 0:12:50# When we want to build Go engineering
0:12:50 > 0:12:53# Engineering
0:12:53 > 0:12:57# When you've got to solve a problem But you don't know how to do it
0:12:57 > 0:13:00# It's time to go engineering
0:13:00 > 0:13:02# Engineering
0:13:02 > 0:13:06# When you want to lift it, stick it, pop it, bend it
0:13:06 > 0:13:09# It's time to go engineering
0:13:09 > 0:13:11# Engineering
0:13:11 > 0:13:13# Go engineering
0:13:13 > 0:13:16# Go engineering
0:13:16 > 0:13:19# When you need to fly it, make it, shape it
0:13:19 > 0:13:20# Engineering
0:13:20 > 0:13:25- # Go engineering - Go engineering
0:13:25 > 0:13:27# When you want to build Go engineering
0:13:29 > 0:13:30# Engineering! #
0:13:32 > 0:13:35Aah, it's been such a great day, man,
0:13:35 > 0:13:36seeing all those bright,
0:13:36 > 0:13:39colourful balloons. There was lots of hot air.
0:13:39 > 0:13:45I've had a fabby day, especially going on a balloon ride!
0:13:45 > 0:13:46Up and away!
0:13:47 > 0:13:50I really enjoyed myself today.
0:13:50 > 0:13:54Shaking the balls around was fun - shaky, shaky!
0:13:54 > 0:13:57Remember, engineers help to build the world.
0:13:57 > 0:14:00They use science to solve problems.
0:14:00 > 0:14:02See you again soon. Bye!
0:14:02 > 0:14:04ALL: Bye!