Alabama's STEM explores is made possible by the generous support of the Holle Family Foundation established to honor the legacy of Brigadier General Everett Holle and his parents, Evelyn and Fred Holle.

Champions of servant leadership, science, technology, engineering, math, all coming up right now on Alabama STEM explorers.

Welcome to Alabama STEM explorers.

My name's Peyton.

Today, we're at the McLane Science Fair with my friend Christopher.

Thank you for having me, Peyton.

Especially on a day like today.

You know, the weather's been changed ing lately.

I don't know if you've noticed, but it's gotten me thinking about, well, where all this weather comes from.

Now, I could talk to a meteorology.

Just.

That's a scientist who studies the weather.

And when you talk to a meteorologist, I find it's a lot like talking to a cook or a baker.

You know how a baker uses the same few ingredients?

Same milk, sugar, flour, butter to make all sorts of different things.

Well, a meteorologist knows that the same three weather ingredients can come together to make all sorts of different weather.

And that's what I want to share with you today.

And we're going to start right here by bringing those three ingredients together in our weather.

Cooking pot.

And we're going to start with temperature.

Now I'm going to need something cold.

Can you think of something cold?

Ice.

Ice.

This cold that's 32 degrees Fahrenheit.

But I can think of something colder than regular ice.

Can you?

Dry ice.

Dry ice is not frozen water.

It's frozen carbon dioxide.

And you're right, it freezes not at 32 degrees, but at -110.

But I've got something even colder than that.

Colder than ice, colder than dry ice, colder than the coldest place on Earth on the coldest day of the year.

It's called a liquid nitrogen.

And it is a staggering negative at 321 degrees.

And it's the first thing I'm going to add to my cooking pot.

And a great time for us both to put on our scientific safety goggles.

But not only that, since I'll be handling the liquid nitrogen, I'll need my special scientific gloves as well.

Now, once again, this liquid nitrogen is -321 degrees.

That's 321 below 003210.

Sounds a little like a countdown, right?

Peter, can I count on you to count down with me?

On the count of three, I'm going to add our temperature to our weather cooking pot.

All right, here we go.

Three, two, one.

There it is.

Almost right away, our liquid nitrogen starts boiling back into a gas.

And speaking of gas, Peyton, this is really embarrassing, but I forgot to bring the next ingredient on our list.

I didn't bring air.

Do you know where I can find some?

Here?

Yeah.

Air is all around us.

So would you mind putting air into our weather?

Cooking pot?

We can do it right from over here.

Perfect.

It's in there.

And just in time for us to add our last ingredient.

And what was that ingredient again?

Temperature.

We've got temperature.

That's our liquid nitrogen.

We've got air.

I think we're missing water.

Water.

So I'm going to pour our water here into this pitcher.

And on one more count of three, I'm going to pour in our very last ingredient.

You know what?

This is a big experiment.

So let's do this one from five.

You can do it all the way from back here.

Trust me, I'm doing you a favor.

Here we go.

In five, four, three, two, one.

Oh, Holy cow.

No, Peyton, Either either I'm wrong or we've made a kind of weather you have seen before.

What does this look like to you?

A cloud?

It does look like a cloud.

But unlike a cloud, way up in the sky, this is sinking down, down, down to the floor.

We've got a name for weather like that, a cloud that sits here at ground level, what do we call it?

Fog and fog is exactly what we've made right here in this very room.

Now, fog is just one of the kinds of weather those three ingredients can make, and it can make some far more extreme weather at that.

But before we get there, let's look at each ingredient on its own and learn what it contributes to our recipe.

But first, let's set this this alright now.

With that out of the way, let's take a look at the ingredients we just put together.

And we'll start with temperature.

Now, to test our temperature, I'll be using this balloon.

Now, take a look.

Peter, is there anything inside my balloon?

No, no, you would think not.

And yet, well, the same thing is in my balloon as is in this room right now.

What is it?

Air.

Air?

Exactly.

Now, is this very hot air?

No.

So is it very cold air?

No.

Which means it's room temperature.

Room temperature.

Exactly.

And a full of a room temperature, air.

Take a look.

It's not very inspiring, is it?

No, no, It sinks to the ground.

It flattens like a pancake.

Pretty deflating an experience.

Yeah, but what if we heat that air up?

What do you think will happen once we make the air inside this balloon?

A whole lot hotter?

Maybe there will go up.

Maybe the air will go up.

That's a perfectly valid hypothesis.

But once we've formed a hypothesis, there's only one way to discover the truth for sure.

What do we have to do?

Try it out.

We have to try it out.

We have to do an experiment.

Now, this experiment may take a few tries, so bear with me, please.

Here we go.

Take a numeral.

Oh, no.

Hands up.

I think I've gotten it because you may already notice a change is my balloon sinking to the ground?

No.

Flattening like a pancake?

No, no.

In fact, it's doing something rather different.

What happened to my balloon?

It went up.

It went up.

And while it was in the air, was it well, flat as it was on the ground?

No, No.

In fact, was in fact.

Well, it got bigger.

And that makes sense when you think about what you and I do on a hot summer day.

I don't know about you, but on a hot, sunny day, I know I like to spread out so cup all those sunny rays and air does the very same thing.

You see air like everything is made of matter molecules.

And as I heat the air up, those molecules get more energetic.

As they get more energetic, they speed up.

As they speed up, they spread out and our balloon gets bigger and bigger.

But that's not what you said earlier.

Earlier, you said it went up, but why did it go up?

To understand that we need to understand density.

Now let's test your knowledge.

We'll start easy.

Which of these is bigger?

The balloon.

The balloon.

So I'm going to hand you my balloon.

Hold onto it for me.

Now.

I'm going to give you these smaller objects now and tell me which one weighs more.

This one.

This one by a lot.

It might be smaller, but it's heavier.

There's literally more stuff crammed inside a smaller space, more stuff in a smaller space.

That's density.

Our weight is more dense.

It turns out that denser objects sink below less dense objects, and the opposite is true, too.

As our air spread out in our balloon, it became less dense than the air around it.

So it didn't sink.

It flew.

It flew, it rose.

Now that's what happens when we heat our air up.

But what would happen if we cool that down To test it out?

We're going to use a balloon.

This balloon now, like any balloon, it's big.

It's puffed up, it's light as a feather.

But will that change as we cool it down?

Well, that's where our liquid nitrogen comes back to play.

Now, in just a moment, Peyton, I'm going to pour our liquid nitrogen in our metal bowl, cooling down our balloon and all the air inside it.

So once our air is colder, what's going to happen next?

It's going to become more dense, kind of become more dense.

Well, that's one hypothesis, but there's only one way to find out the truth for sure.

What do we have to do?

Test it out?

We have to test it out.

And that's exactly what we're going to do now, just like before, I'll be pouring my liquid nitrogen in to our bowl.

Now, remember, liquid nitrogen is 321 below 03210.

Can I count on you for another countdown?

Yeah.

Here we go.

In three, two, one, zero.

Here we go.

Now, I want you to notice any changes at all, starting with what you see here.

Peyton.

Is this usually, what, a balloon sounds like?

No, No.

What do you hear?

It sounds like crunching leaves.

Like crunchy crackly.

Not that bouncy, rubbery balloon we saw earlier.

Speaking of which, do you remember what our balloon looked like?

Big and puffy?

Did it look anything at all like this?

No, no.

Our balloon got small.

Not only that.

Well, it sinks to the ground like a stone.

So did our balloon pop.

Hold on.

Look, as it heats back up, it goes right back to its original size and shape.

So what's going on here?

Well, to understand it, think about what we do on a cold winter's day.

I don't know about you, but when I get cold, I like to get nice and small, cuddle together with all the blankets around me.

And air does the very same thing.

Air is made of matter molecules.

As those molecules cool down, they slow down.

As they slow down, they gather in together.

As they scrunch up together, our balloon gets smaller.

Smaller.

Not only that, you were right.

It got more dense.

Meaning?

Was it quite as light as it was before?

No, no, it's sank.

Peyton, we've learned something really interesting about temperature.

We learned that hot air rises and expands its, but cold air shrinks and sinks.

But there's one more ingredient we have yet to test.

We've seen temperature, We've seen air.

What are we leaving out?

Water.

Water.

Unfortunately, yeah.

I poured all my water out.

So where else can I get water?

I don't know.

Well, what if I told you there's water in the air we breathe.

About 3% of the air we breathe is made up of tiny, invisible droplets of water called water vapor.

And there's water in the air you breathe out as well.

So if I want to capture that invisible water, I'm going to need to take your breath away.

Now, Peter, can you do me a favor?

Yes.

I need you to get this balloon about the size of a basketball.

You think you can do that for me?

Yeah.

All right, Now, as you inflate your balloon, let's think about what's going into that ball.

Not only carbon dioxide, but oxygen, nitrogen, water vapor and a yes spit.

Now, that'll come back into play later.

But in the meantime, that looks good to me.

I'll take that from you.

Tie it off and we're going to test it out now, just like before.

Peyton we're going to be cooling your balloon down, but this time it will be your breath.

And we've seen what happens to the outside of a balloon as that air cools down.

We're about to find out what happens to the inside.

Now, I want you to form a hypothesis.

When you cut this balloon open, what do you think we'll see inside?

Nothing.

Nothing at all?

Absolutely.

After all, air is invisible, is it not?

Well, here's what you're going to do.

I'm going to give you these scissors.

When I bring you the balloon.

You're going to snip straight down the middle.

Think you can do that for me?

Let's see what happens next.

All right, Go ahead.

Cut it open.

Just like that and take a look.

Payton, can you hold on to that for me, please?

And what do you see?

Swirl it around a white liquid.

A white liquid.

Payton, you're literally holding your breath.

That's your breath as a liquid, of course.

See all that frozen get left?

Well, that's your spit.

So we'll put that aside for now.

You see, as we cool the air down, draw it closer, it becomes a new state of matter from a gas to a liquid.

Liquid.

Exactly.

And believe it or not, you've seen this before.

You didn't need liquid nitrogen to do it.

Ever walk outside on a cold winter day?

Breathe out.

What do you see?

So you see fog.

That's water vapor from your breath, cooling into a liquid.

See all this?

Yes.

That's not nitrogen, that's water vapor.

So we'd seen so, so much and learned so much.

We've learned that as air heats up, where does it go?

Up?

Up.

And it carries all that invisible water vapor with it.

Of course, we know from experience, the higher we go, the colder it gets.

That's why the tops of mountains and only the tops are often covered in snow.

Cold air goes where?

Down, down.

And it leaves those clouds behind.

We have hot, rising, wet air and cold, sinking dry air that's going to start to rub together.

Rub together like your socks on a carpet.

Have you ever rubbed your socks on a carpet before?

Yeah.

Then you know what it feels like to build up static electricity.

Now we don't have huge masses of air in this room, but we do have this.

This is a Van de Graaff generator, and it's basically a giant socks on a carpet machine.

So here's what you're going to do.

Peyton, you can leave your goggles here on my science desk, and I'd like you to walk up these steps here.

Once you're at the top, go ahead and place your hands on our Van de Graaf dome.

Now, when I turn it on, this belt is going to start spinning and building up static electricity like our hot, wet air does is it rubs against our cold, dry air.

Ever wonder what a static feels like?

Let's find out.

Here we go.

In three, two, one.

Now, Peyton, already You should feel something changing, something different.

A little peculiar.

Could you do me a favor and shake out your hair for me?

What do you feel?

You feel that static in your body?

Well, I'm going to stop our banded graph, and we're going to wait for it to slow down.

Now go ahead and take your hands off and wander down.

First of all, thank you for doing that, Peyton.

Great job.

You can join me back behind the desk and we're going to talk about what we learned.

Well, welcome back.

Now, Peyton, did you notice your hair standing on end?

Yes.

You often feel this before a lightning strike if you ever notice your hair standing up, just as it did before.

Well, that means it's time to take cover.

And speaking of which, well, they often say don't sweat the small stuff, but weather has its own ideas.

You see, as things cool down, they change their density, same as when they heat up.

Air likes to move from areas that are cold to areas that are warm.

They like to move from areas of high pressure to areas of low pressure.

The faster that movement, the faster the wind, the faster the wind, the faster the degree.

And that can spell pretty dire consequences.

But no use talking about it.

Do you want to see what I mean?

Yes.

Well, to do it, we're going to need McWanes Science Center's patented state of the Art storm launcher.

So I'll be right back.

Don't go anywhere.

All right.

Here we are back with McWanes Science Center's patented state of the art pencil launcher.

Now, why bring out a device like this for a talk about weather after all?

Well, isn't weather just a sunshiny day, a walk in the park, a little breeze on the skin?

Well, weather can be a lot more than that.

What if I told you Storms, hurricanes have been known to hurl lightweight debris like this pencil up to 400 miles per hour.

Well, let's put it another way.

I want you to put this pencil through this piece of wood a quarter inch thick.

You feel confident you can do it?

Maybe that's the spirit.

All right, here we go.

In 3 to 1.

Okay.

Three, two, one.

And oh, well, not even a mark.

So do you think it's even possible to put a pencil through a piece of wood?

Maybe.

May be with a little wind on our side, as I said earlier.

Well, air moves from areas of high pressure to areas of low pressure.

As things get cold, they build up in pressure, warm up.

They release that pressure.

Now, the higher the difference in those two areas, the faster that air moves.

That means the difference between a light breeze and a Category five hurricane.

Now, I can talk about the difference all day long, but I think it might be more effective to show you.

What do you say?

Let's do it.

All right, then.

Into this end of our storm launcher, I have our projectile, our simple on sharpened pencil.

So into the chamber it goes close, that uptight.

And there it is behind, protected and very thick.

Plexiglass, of course, will need our target at the other end.

And so back in this slot goes our what?

Let's tighten it up.

Make sure it can't budge an inch.

Can you test my handiwork?

Not going anywhere.

I'll get it a little lower so I can close the lid and we'll be just about ready to launch now.

Yeah, No.

Good.

All right, then.

Let's close our device tight.

Now, in just a moment, when I press this button, I'm going to be releasing 120 p s i.

That's pounds per square inch.

And that's a measurement of pressure here.

And believe me when I say 120 PSI, that's a whole lot of pressure.

Have you ever felt under pressure, Peyton?

Yes.

Well, doesn't hold a candle to this.

You're ready to see what 121 PSI really looks like?

Of course, I think this deserves a big countdown here we go.

from five, four, three, two, one, And not only did our pencil go right through it, split in half.

So the next time someone told tells you to shelter in place because there's a storm coming, well, it might be time to sweat the small stuff.

I hope you've seen how these three simple ingredients, air temperature and water, can come together to make all kinds of weather small and big.

Well, thank you for having me at the McWane Science Center today.

A pleasure.

As always.

Taking in your welcome back anytime.

And we'll see you next week for another episode of Alabama STEM Explorers.

Thanks for watching.

Alabama STEM Explorers.

If you missed anything or you want to watch something again, you can check out our website at Frame of Minds dot org.

maybe you have a STEM question we could answer here on the show.

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Thanks again for watching.

We'll be back next week.

Alabama STEM explorers is made possible by the generous support of the Holle Family Foundation established to honor the legacy of Brigadier General Everett Holle and his parents, Evelyn and Fred Holle.

Champions of servant leadership.