(upbeat music) - Magic is creating the illusion that you can defy the laws of nature.

(upbeat mysterious music) (energetic music) (energetic music continues) - [Audience] Wow, how did he do that?

(energetic music) (crayons shaking) (energetic music) - [Audience] Whoa!

(energetic music) (audience applauds and cheers) - Magic is creating the illusion that you can defy the laws of nature.

Science is the study of how the natural world works.

This is science.

(audience cheers and applauds) The earth is an incredible place.

Seen from space, it's easy to understand why it's sometimes called the blue planet.

The fact that nearly 70% of the Earth's surface is covered with water.

Along with the way light passes through its atmosphere gives it the appearance of a big blue marble, moving through space.

It moves silently, of course.

And from this distance, it's surface appears perfectly smooth.

From this distance, it is smooth.

We know, of course, that the earth is covered with mountains and valleys, as well as canyons and hills but it certainly looks smooth.

Did you know that if the earth were shrunk down to this size, it would be smoother than this pool ball?

It's true.

Even though the surface of the earth is covered with high mountains and deep oceans it would appear smoother than this ball.

But the earth isn't the size of this pool ball.

And regardless of how it looks from space, it's not smooth.

The earth is covered with land forms and water forms such as mountains, and valley, and oceans, and rivers.

Land forms are features that cover the earth's surface.

They are both above and below the surface of the water.

Sometimes we refer to land forms as terrain.

There are many different types of landforms, or terrain, Mountains, plains, and valleys, those are all landforms.

Landforms come in different sizes.

Some are huge and some are pretty small.

The largest landforms are called continents.

- [Speaker] Oh wow.

- Continents are really, really large, continuous land masses.

I mean, they are really large.

They cover around 30% of the surface of the earth.

There are a few different ways to divide them up but we often say there are seven continents.

From largest to smallest they are: Asia, Africa, North America, South America, Antarctica, Europe, and Australia.

While we're talking about really big things, let's also look at some water forms.

A water form is just a body of water.

The largest ones are called oceans.

Again, there are different ways to divide them but we often see them as a list of five.

There's the Atlantic Ocean, and the Pacific Ocean, there's also the Indian Ocean, the Southern Ocean, and the Arctic Ocean.

When you compare them to continents, other landforms really start to appear a lot smaller but some can still be huge.

For example, mountains such as these, are land forms.

Mountains take up thousands of square miles and can reach nearly six miles up into the air.

Did you get that?

Mountains can reach nearly six miles.

- [Speaker] Oh wow - Up into the air.

It's easy to think that nothing can take up as much space as a mountain range because they are huge but another huge landform that can take up just as much room is a plain.

By some measures, the Great Plains regions of the United States takes up around a half a million square miles.

That's more area than is covered by the entire Rocky Mountain region.

Plateaus are sort of a combination of mountains and plains.

A plateau is a large flat region surrounded by slopes.

Plateaus can be very large as well.

The Cumberland Plateau is part of the Appalachian Mountain range and extends across parts of Alabama, Tennessee, and Kentucky.

We can see how there are landforms that are really, really big, yet are still smaller than continents.

In the same way there are water forms that are smaller than oceans yet still take up huge areas.

This picture is of a map of the Great Lakes.

The Great Lakes are the largest group of lakes on earth.

If you're talking about their surface area, rivers can also be really large.

The Mississippi River stretches from the state of Minnesota to Louisiana, that is more than 2000 miles.

- [Speaker] Oh, wow.

- As we start to look at smaller land forms and smaller water forms we can see there are many different kinds.

Like mountains, hills are land forms that are higher than the land surrounding them but they're not nearly as big.

Lakes can also be smaller.

Unlike the Great Lakes many lakes are small enough for you to see across them.

There are many other types of land forms.

This is a valley, a low area surrounded by mountains or hills.

A canyon is similar to a valley but the sides of it are much steeper.

A saddle is a low area between two hills.

Bays are coastal bodies of water connected to an ocean or a lake.

The land around them shelters them from the waves and other effects of the ocean or lake.

There are many kinds of landforms.

Now let's take a look at how landforms are made.

How did a mountain form?

How did the Grand Canyon form?

Hmm.

What about rivers and lakes?

Perhaps you know that the scientific definition of force is an influence that can change the motion of an object.

Force can cause something to move or to stop moving.

It can speed up or slow down a moving object.

Force is usually referred to as a push or a pull, and force is what creates land forms.

There are two types of forces that create land and water forms.

One type of force is constructive force.

Think about the word construct.

That word means to make something.

That's what a constructive force is.

A force that makes something that wasn't there before.

The other type of force that creates land forms is destructive force.

Think about the word destructive.

That means to destroy or tear down something.

A destructive force makes a land form by taking away earth material.

As you can imagine, it takes a lot of force to create something like a mountain or a canyon.

It takes a lot of force and usually it takes a lot of time.

With just a few exceptions, constructive and destructive forces act slowly, very slowly.

Let's look at constructive forces.

Remember construct means to make something that wasn't there before.

One of the most dramatic constructive forces is a volcano.

To understand a volcano it's important to know how the earth is put together.

The earth has a few layers and all of them are different.

The outer layer of the earth is called the crust because, well, it's like a crust.

It's hard and solid, made of rock, and with a thin covering of soil.

Below that is the mantle.

The mantle is mostly solid but its outer layer is molten and can move freely.

Below the mantle is the core.

The core is usually described as being two parts, the outer and inner core.

Okay, back to the volcano.

A volcano occurs where there is an opening in the crust.

The opening might be a rupture in the crust or it might be where two tectonic plates come together.

Tectonic plates are large sections of the earth's crust that sort of float on the mantle.

When the material in the mantle is allowed to escape between or through the plates, it comes to the surface as lava.

Above ground it's called lava, below ground it's called magma.

Cooled lava is a type of rock.

And the collected lava can form huge mountains.

The Hawaiian islands are examples of landforms.

Mountains and hills that were formed by volcanoes.

This picture of famous Waikiki Beach shows the diamond head crater in the background.

It's inactive now.

That crater allowed molten rock to escape from below the earth, helping to form the island of Oahu.

Volcanic eruptions are an example of a constructive force.

An opening occurred between the plates in the Pacific Ocean, lava came out and collected, and the Hawaiian islands were formed.

Yay for volcanoes.

Another constructive force is sediment deposition.

Let's break that down.

Sediment is nothing more than tiny pieces of rock.

Sand is an example of sediment.

Sand is literally tiny pieces of rock.

But there are particles even smaller than sand, sediment.

Sediment is carried by wind or water from one place to another.

As the sediment is carried, it is deposited where it starts to collect with other sediment.

Deposition deposited.

Deposition deposited.

Sediment deposition is the result of tiny pieces of rock, or sediment, that are carried someplace and deposited there.

In this picture, you can see how material is collecting at the mouth of this river.

The land is expanding out into the lake.

This is the result of sediment deposition.

Sediment deposition also forms islands, like these barrier islands.

Many of the hills and mountains of Alabama, Georgia, and Tennessee were formed millions of years ago when sands settled before hardening into sandstone.

Earlier I talked about the layers of the earth.

I said that the outer layer is called the crust and then later I talked about how the crust is actually made up of plates.

They don't move very fast but those plates are always moving.

As they move, they bump up against one another or move away from one another.

This doesn't have to happen just at the edges of the plates.

Sometimes it happens at small cracks, or faults, in the middle of the plates.

When we can actually feel the plates move we call that an earthquake.

(ground rumbles) The ground is moving and we can feel it.

Those three forces, volcanoes, sediment deposition, and crustal deformation are constructive forces.

They put earth material where it wasn't before.

So what about those destructive forces I mentioned earlier?

Destructive forces make land forms by taking away material.

There are two primary destructive forces, weathering and erosion.

Both of these forces are very powerful.

Both can happen slowly or quickly.

Weathering is when big rocks are turned into small rocks.

There are two types of weathering.

Physical weathering is when rocks are actually broken up into smaller pieces.

This often happens when water seeps into a crack and freezes, the expanding water breaks the rock.

This can also happen when a tree or other plant grows in a crack in a rock.

The roots expand and the rock is broken.

Tree roots are pretty powerful.

In addition to physical weathering there is also chemical weathering.

This takes place through chemical reactions.

These reactions cause the rock to rust or dissolve.

Chemical weathering is very powerful.

Huge cave systems, such as Mammoth Cave, were formed by water reacting with rock such as limestone.

The second type of destructive force is erosion.

Erosion is when earth material such as rock, sand, and soil is actually moved.

This movement might take place by wind, water, or just plain old gravity.

As you can see here in this picture of the Grand Canyon erosion is quite a powerful force.

Rivers, both big and small are also formed by erosion.

Once water starts to flow, watch out.

Erosion is taking place.

The earth is pretty amazing.

It's covered with land forms that are also pretty amazing.

These land forms and the forces that cause them are also pretty amazing.

Earth, our home, is really, really quite amazing.

(upbeat music) I love social media.

It's remarkable being able to connect with people all over the world instantly.

I have a famous friend that said something mean about another person on Twitter.

Later after my friend thought about it, he deleted the tweet and then he tweeted that he was sorry for being mean.

I tweeted a compliment to him for trying to be better and not be mean.

In the meantime, someone else said something mean to me about my tweet.

I really, really wanted to write something mean and hilarious back.

It was funny, but really mean.

I did not respond at all.

Days later, I responded to that mean tweet and said, "I understand what you meant and thought that the most important thing was my friend was trying to be better."

He was, we all mess up.

When we do, the best thing is to say you're sorry and try to do better in the future.

(upbeat music) Magic is creating the illusion that you can defy the laws of nature.

(upbeat mysterious music) (energetic music) (energetic music continues) (audiences laughs) (energetic music) Magic is creating the illusion that you can defy the laws of nature, Science is the study of how the natural world works.

This is science.

(upbeat music) (audience cheers and applauds) There are more than 700 named muscles in the human body.

I thought I'd stay very still and not move a muscle but it isn't working and that's very good news.

Many of my muscles are moving even though I'm standing as still as I can.

My heart is still beating.

I'm still breathing.

My stomach is digesting my lunch.

I'm blinking to keep my eyes comfortable.

You and I have a whole bunch of muscles that work all of the time, whether we're trying to move them or not.

Our heart, also called the cardiac muscle, works nonstop.

It works for us all the time.

It pumps the blood we need through our body.

It does this even when we are sleeping.

My heart is very busy.

How much blood is my heart pumping in a circle through my body?

A lot.

Every day, an average adult heart could pump out as much blood as this tank will hold, 2,500 gallons.

It does this every day, every day of your life.

- [Speaker] Oh wow.

- That's kind of amazing, isn't it?

Yes, it is.

Your heart muscles beat on their own whether you are thinking about them or not.

There are also some muscles that work all the time but that you can control.

For example, my eyes, they blink all day whether I'm thinking about them or not but I'm also able to make them blink.

I'm very good at blinking.

See.

(drum roll) You breathe without thinking about it as well, but again you can control it.

(breathes deeply) (drum roll) (breathes rapidly) I'm also a pretty good dancer.

Muscles do so many things.

Muscles generate heat to keep our bodies warm.

Muscles help keep your joints stable and your posture strong, Muscles pump blood, and other liquids, through our bodies to keep all of our cells energized.

How can they do so many jobs?

Muscles even make it possible to talk.

We'll use this as a model.

Inside your body are your vocal cords.

As air passes between your vocal cords muscles pull on them to change the pitch of your voice.

Did you know that your vocal cords are muscles?

(balloon squeaks) That's how you can (balloon squeaks) change the pitch of your voice.

(balloon squeaks) It's all controlled by muscles.

In fact, you might be able to feel your vocal cords vibrate.

Put your fingers on the middle of your throat, about right here and talk.

Cha cha cha.

Can you feel that movement?

That's your vocal chords vibrating.

Then the muscles of your mouth and tongue change the way those noise vibrations come out.

La-la-la-la-la-la-la.

My vocal chords are making noises and my mouth and tongue are changing them into words.

And that's not the only way muscles help us to communicate.

There are 43 muscles just in your face and they are great for non-verbal communications.

You can show surprise.

There's disgust.

Anger.

Fear.

And all the other emotions.

There are four major muscle groups in your body.

There are the muscles of your head and neck, muscles of the upper extremities, the muscles of the trunk of your body, (elephant roars) and the muscles of the lower extremities.

Your muscles are connected to your bones by tendons.

Tendons are cords that are flexible.

Tendons are flexible but not stretchy.

Hmm, like rope.

See, flexible (springing sound) but not stretchy.

(bell dings) They move like this, (springing sound) but not like this.

(bell dings) There are even different types of muscles.

The kinds we usually think of are called skeletal muscles.

They help your body move when you're thinking about it.

There are smooth muscles also called visceral muscles.

The visceral muscles are inside your organs like your stomach, intestines, and some blood vessels.

They contract to move food from your stomach and blood through some parts of your veins and arteries.

There is also a type of muscle that is only in your heart.

They're called cardiac muscles.

And when these muscles contract they pump blood through your body.

(heart beat) You may have noticed when I'm demonstrating what muscles do I'm only squeezing.

See.

(heart beats) This is gonna' seem crazy, but the only thing muscles can do is contract.

Muscles never push.

They can only pull.

That sounds impossible.

With all the things I can do the muscles in my body can only pull.

How is that possible?

How can I jump up?

(springing sound) There are eight muscles in my tongue and if they all only pull how do I stick my tongue out?

How can I push my arm out with only muscles that pull?

This sounds impossible.

So I've built this device to test it.

One of the great things about science is when something seems wrong you can often test it for yourself and that's what I'm gonna' do.

I'm going to use this model to try to answer this question.

How can I push my arm using only muscles that pull?

You can see this is a little like an arm.

Where the muscles might be, I've installed a bungee cord like this one.

As you can see, it stretches out but on its own it can only pull.

You can't really push anything with a bungee cord.

Let's do the test.

I'll pull this fake arm so our bungee cord is stretched out and tight.

I can lock it in place by holding it.

In your body, skeletal muscles are activated by an impulse from a nerve cell.

Me holding the boxing gloves will be like a fake nerve cell.

When I let go of it, our bungee muscle will hopefully contract.

Now let's see what happens when we activate our nerve cell to contract the muscle.

(bell dings) (birds chirp) - [Speaker] Let's see that again in slow motion.

- [Speaker 2] Okay.

(bell dings) (birds chirp) (birds chirp) Looks like it works.

The human body is really amazing.

Muscles are really amazing, and you are too.

- [Speaker 3] And now something silly.

(upbeat music) - Okay, I'm gonna' need a towel and you're gonna' need to move.

In your body skeletal muscles are activated by something that I can't remember.

Nerve and puzzle.

- [Person Off Camera] Key words here.

Rolling after lunch, 150 to 175.

(Steve laughs) All right, talking about sediment deposits.

- Oh, sediments and deposits.

Cut, woo, we're so good.

(upbeat rock music) ♪ Biologically, chemically, atomically ♪ ♪ Everything is connected ♪ (upbeat rock music continues) ♪ Everything is connected ♪ ♪ Everything ♪ - [Announcer] Major funding for this program provided by Jason Isbell and Amanda Shires, Keep Alabama Beautiful, and Northrop Grumman.

♪ Yes the ocean is deep ♪ ♪ And the sky is so high ♪ ♪ And the earth is so wide ♪ ♪ It's a mystery, but deep down everyone knows ♪