Summary:
Watch the video and think about:
• the different things that are hotter or colder than our bodies
• any possible effects of warm air rising and cool air sinking.
Captions:
Ruben Meermen: Music
Child: The Surfing scientist is the best.
Children: Three
Ruben Meermen: Uh oh.
Child: The Surfing scientist is awesome.
Child: Surfing science is like amazing.
Ruben Meermen: Now it's time to start doing experiments with this stuff. What do you think?
Children: Yes
Ruben Meermen: Oh yes. Alright, well let's get rid of all these little bits and pieces. We'll chuck this under there and we'll start with just by having a look at what this liquid looks like.
So, I'm going to put my beaker here. I'm going to put on some gloves because it's a little bit dangerous. Don't worry about where you're sitting, it's very safe.
But where I'm standing I have to wear gloves and I also need to wear some goggles to protect my eyes. Now we are ready to have a look at it.
Let's pour some in the beaker for starters and just see what it looks like. That's pretty amazing isn't it? Here it comes. Liquid nitrogen. Hello.
Now can you see that inside this container there's a clear liquid. Looks a lot like water doesn't it?
But it looks like water when you put it onto the stove and make it really hot. It looks like boiling water.
Now the first thing we want to figure out when you see liquid nitrogen is because it looks so much like hot water a lot of people wonder if it's hot or cold.
So, here's a really good way to figure out if it's hot or cold. Have a look at this cloud. Which way is it going? Up or down?
Children: Down
Ruben Meermen: Down. And if someone's boiling a kettle for a cup of tea, which way does the cloud go? Up or down?
Children: Up
Ruben Meermen: Up, so do you reckon this is hot or cold?
Children: Cold.
Ruben Meermen: Oh, very good. Now to find out just how cold it is we are going to do a really cool experiment. Experiment number one.
We're going to pour liquid nitrogen into a great big bucket of water to see if. Well what does water turn into if you make it really cold?
Children: Ice
Ruben Meermen: Ice. So, let's pour some liquid nitrogen into this container of water and we'll see if we can make any ice. Now think about this.
Big container of water like this in your freezer at home would it take a long time or a short time to get some ice?
Children: Long.
Ruben Meermen: It would take a pretty long time wouldn't it? Alright well let's see how the liquid nitrogen can do it. On the count of three.
Ruben and children: One, two, three.
Ruben Meermen: Wow, have a look at that. It's making heaps of this amazing cloud and if you are wondering what that is. Have you ever breathed out on a very cold morning? And you get a cloud.
Child: Yes, frost.
Ruben Meermen: Fog, so this cloud here is made up of exactly the same stuff that comes out of your mouth. It's just a cloud made out of water. It doesn't last for very long.
Can you see that it's completely evaporating before it hits the ground. And look at that.
And look at that. And because that cloud's in the way I can't quite see if there's any ice in here yet. So let's have a look. Is there any ice?
Get out of the road cloud. I think there is some ice. I just need to wait a little bit for the liquid nitrogen to evaporate away, then I can reach in and grab out yes there it is.
Let's see if I can grab it out for you, have a look at, oh it broke oh come here, oh I keep breaking it there it is look at that it's made ice. So what does that tell you about liquid nitrogen? Is it hot or cold?
Children: Cold
Ruben Meermen: And it must be a lot colder than your freezer at home because your freezer's about five degrees below zero or maybe minus ten roughly depends on how old your freezer is but it takes ages to make ice.
This stuff does it like really fast so it must be colder. I'll tell you how cold it is after I have had a little bite of the ice. Mm beautiful, you can eat this ice.
You shouldn't eat your experiments if you don't know what they are but that one's pretty safe because it's just water that's been turned into ice.
Now this stuff, a lot colder than your freezer. It's even colder that the coldest day ever on planet earth that we know of.
The coldest day ever that we know of is minus eighty nine degrees Celsius in Antarctica. That's in the Guinness book of records.
You can check it up. But this stuff is minus one hundred and ninety six degrees Celsius.
So probably the coldest thing you are ever going to see and also very, very useful for doing experiments
Ruben Meermen: .
Summary:
Watch as Ruben shows us what happens when liquid nitrogen is poured over a balloon and consider these questions:
• What happens to air when we make it cold or warm?
• What might happen when you heat or cool a solid?
Captions:
Ruben Meerman: Right we're going to blow up a balloon and pour liquid nitrogen all over it to see what happens to the air inside. So first of all. Got to blow it up.
And I want you to remember that I'm tying a knot in this balloon and that the knot stops all of the air escaping back out of the balloon. So we'll put it there.
Invisible air trapped inside a nice, big beautiful blue balloon. Let's pour liquid nitrogen all over it and see what happens. What do you reckon might happen? Will it pop? Dunno.
Maybe it'll change colour or maybe it'll change shape, maybe it'll become a giraffe shape balloon. Who knows.
Well let's find out. We'll start pouring on the liquid nitrogen on the count of three. There's a lot of fog so it's hard to see. But here we go.
Ruben and children: One, two, three.
Ruben Meerman: Oh it didn't pop. But it's doing something now. Hello ah.
Children: It's shrinking.
Ruben Meerman: It's shrinking. And, can you hear it? Sounds like a …
Child: plastic bag
Ruben Meerman: Sounds like a plastic bag. And it's nearly all gone. Amazing well, I should be able to squash it so that it looks like there's absolutely no air left in here.
Ruben Meerman: But here's the amazing thing. Remember I tied a knot in the balloon?
Children: Yes
Ruben Meerman: No air can get out of this balloon so what you are seeing is what happens to air when you make it cold. It shrinks.
It gets smaller. Now if air gets smaller when you make it cold, what do you think is going to happen when we take the balloon out of the liquid nitrogen again and let it get warm. Well it get even smaller or will it get
Children: bigger
Ruben Meerman: Very good. Alright, well let's take it out of there and see if you're right. Here comes the balloon, looks a little bit unhealthy doesn't it? But something's happening.
What if I blow on it? It's getting bigger. It sounds funny doesn't it? It's crackling. And look, that looks like Antarctica.
Children: Laughter
Ruben Meerman: And that sort of looked a bit like global warming. Did you see it all disappear? Wow. Well it's back to normal.
You were right. The balloon got bigger when we heated it up again. That's a pretty cool trick.
.
Summary:
As you watch the video, think about:
• the effect of the Sun cooling and warming the air around the Earth
• how day and night is related to the Earth spinning in space.
Captions:
Ruben Meerman: Let's do it with one of these balloons. These are hilarious. You can turn them into, well you can turn them into balloon dogs and I can make two types of balloon dog
I can make either a poodle or a sausage dog. What do you prefer poodle or a sausage dog?
Children: Poodle, poodle, sausage
Ruben Meerman: Hands up for a poodle and hands up for a sausage dog. Oh sorry poodle's going to win today. You beauty. Well let's blow the balloon up a little bit first and then we'll
Child: The poodle's going to die.
Ruben Meerman: Well let's see what happens. First of all I better teach you how to do this because I won't have time to make all of you a sausage, a poodle I should say
so I'm going to teach you how to make a poodle and then you'll be able to make your own.
So you start by making a bubble for a head but you have to hang on to that for the moment because if you let go it just comes undone.
So make a bubble for head and then make two more bubbles for ears. There's two little bubbles and join them together like so and them twist them around
and now you've got two little ears and a cute little head.
Just repeat the same thing to make some legs. So we'll make another bubble for a neck and then two bubbles for legs and you do exactly the same thing I did with the ears.
You bring them together like so and you twist them together and you’ve got a pair of legs.
Now you need just two more legs at the back and we're nearly there, one two there they are join them together, twist them and to finish him off we've got to give him a cute little pom pom on the end of his tail.
And that's really simple. You just squeeze a little bit of bubble up towards his tail and you've got a poodle.
Oh he's so cute. His name is Pepe.
No Pepe is going to perform his death defying liquid nitrogen dive.
Child: I bet he comes alive again.
Ruben Meerman: He'll be alright. I can see a few of you are a little bit worried about him. Don't panic. He's only going to dive into this beaker. He's only a balloon. Don't try this with a real poodle.
We'll fill it up a little bit more. And then we'll see how he goes. I think he'll be OK. Now a little bit more in there.
Righto now on the count of three, Pepe the stunt poodle performing the liquid nitrogen dive.
Ruben and children: One, two, three
Ruben Meerman: Oh in you go Pepe.
Children: Laughter, look at its tail.
Ruben Meerman: Poor little fella. Hey Pepe, hello. I'm not sure if he's feeling too well. Maybe we'll fish him out of there with the rescue tongs. Here he comes.
Now this is his best trick, it's called coming back to life. Here we go, one, two, three. Hello Pepe, hello.
How are you feeling? Not too good. We'll grab him by the tail and uh oh. Here he comes. Pepe. Oh my goodness coming back to life.
What's happened to you mate. He's lost his tail and look at his little nose it's all frozen. We'll defrost his little nose and he's sort of a bit twisted up isn't he?
We might just fix his back legs and we'll fix his front and we'll fix his. Is he better yet?
Child: No
Ruben Meerman: We need to fix this too. This is a very complicated medical procedure. We'll squeeze here and we should get his tail back there. On the count of three.
Ruben and children: One, two three
Ruben Meerman: Hey look and it's back. And he's even wagging it, oh you beauty. Now I think I'll leave Pepe here with your teacher today and maybe your teacher can decide who gets to take Pepe home.
If it's you, please be careful with him I know he looks cute doesn't he? He's got a cute little button nose, cute little tail looks friendly doesn't he but in actual fact ruff! Oh sorry.
Naughty dog he's not trained so just keep him on a short leash. But we'll let him go and have a bit of a sleep for now so you might want to say goodnight Pepe.
Ruben and children: Goodnight Pepe.
Ruben Meerman: Off you go and he's going for a little sleep.
We're going to do more experiments but hopefully you'll remember that experiment because next time you're learning about the weather just remember that the weather happens on planet earth
because we have this stuff called air and where's my big balloon gone.I'll just grab it. Hey hey come back. Hey got it.
Got away from me. Well you know the stuff in here it's invisible stuff called air and you know that the planet that we live on planet earth is surrounded it's got a blanket of this air stuff around it.
And you also know that planet earth does this every day right, we spin. And if the sun was over there shining on this side of planet earth then this would be the daytime side and this would be the
Ruben and children: night time side.
Ruben Meerman: And as spin out of sunlight you also know that the sun is really, really hot so it makes everything warm
and now you know by having seen this experiment that the air on this side of planet earth even though it's invisible and you can't see it you know that when it heats up because the sun's shining.
What does air do when you heat it up?It gets a little bit
Ruben and children: bigger.
Ruben Meerman: And on this side of planet earth, night time when the sun goes down the air cools down and gets a little bit
Ruben and children: smaller.
Ruben Meerman: And that is what gives us weather on planet earth. It's amazing. Such a simple thing does all of our amazing weather, so I reckon it's pretty cool.
Ruben and children: One, two, three
Child: The surfing scientist is cool and amazing.
Child: The surfing scientist has cool experiments.
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