- Today on Extra Credit, we visit a cave that's over five million years old!

Plus we meet some unsung heroes.

Stay tuned.

(upbeat music) Hi, I'm Mrs. Pizzo.

I'm pleased to meet all of you.

Welcome to Extra Credit where we meet interesting people, explore new ideas, and discover fun places together.

Each episode, we'll introduce you to people who use math, science, sports, and writing to make the world an interesting place.

We have so many great things in store today, but first, I want you to meet our co-host.

- Hi friends.

My name is Emily and I'm so happy to hang out with you today.

Today's theme is Across America.

So, let's celebrate some amazing, important Americans.

I wonder what life would be like without them.

First, let's meet some legends who saved the U.S. space program.

(upbeat music) - Do you know about the woman who saved the American space program?

How about the woman who helped advance the treatment of leprosy?

Can you name the first American woman to receive a PhD in chemistry?

Their accomplishments were nearly lost history, but now, Reactions celebrates some of the great unsung women of chemistry.

(upbeat music) (swiping) In 1957, the Soviet Union launched the first earth-orbiting satellite, Sputnik.

When the first pings of that satellite were heard in the U.S., scientists went into overdrive.

At the time, most American rockets were still exploding at the launch pad and if they made it into air, they didn't have enough power to get into orbit.

The answer to our power problem was better fuel and that's exactly where Mary Sherman Morgan comes in.

Mary worked at North American Aviation, the company tasked with finding a better rocket fuel.

She was the only woman out of 900 scientists working at North American Aviation and the only one without a college degree.

Mary and her team developed a new propellant cocktail called hydine to power the Army's Jupiter-C rocket, which was developed by a much more famous Wernher von Braun.

On January 31, 1958, Jupiter-C with the help of hydine, delivered America's first satellite to space.

Dubbed Explorer-I, the satellite's successful launch was the boost the American space program needed.

Without Mary, the U.S. would've continued to trail behind the USSR in the space race.

Mary's work was top secret and she kept it that way.

She was also fiercely private and her accomplishments were lost among a litany of other amazing space achievements since.

When she died, her son George sat down with some of her former North American Aviation colleagues.

One leaned over and said, "Your mom single-handedly saved the America's space program "and nobody knows it but a handful of old men."

Decades before Mary Sherman Morgan was working at the chemist bench, Alice Ball was working on a better treatment for a very old disease, leprosy.

In 1873, we learned, thanks to Dr. Gerhard Hansen, that leprosy was caused by a bacteria.

We knew the cause and now, we needed a better treatment.

At the time, the best treatment for leprosy were injections of chaulmoogra oil, but the results were spotty, the side effects were unpleasant, and the injections were painful.

Despite all of this, scientists and physicians kept coming back to this nut oil.

Something in it seemed to help patients.

But what was it?

That's where Alice comes in.

Alice was a whiz at natural products chemistry, just the kind of work that was needed on chaulmoogra oil.

By early 1916, she cracked it!

She developed a process to isolate active constituents in chaulmoogra nut oil.

These were fatty acids in the form of ethyl esters.

Injection of these esters provided a more effective relief of leprosy symptoms with considerably less pain and discomfort than shots of the straight oil.

The new treatment was used for decades afterwards.

Sadly, 1916 would also see the end of Alice's all too brief career in chemistry.

On New Year's Eve, at just 24 years old, Alice died.

She never got to see the impact of her work on the treatment of leprosy and for a long time, Alice never got credit.

After her death, another chemist at the college continued her project, but published without any mention of Alice or her previous work.

It was decades before the extent of Alice's contributions were recognized.

Almost 90 years after her death, Alice Ball was awarded the University of Hawaii regions Medal of Distinction.

Finally, I wanna recognize an exceptional woman from my alma mater, the University of Nebraska Lincoln.

Rachel Lloyd was a woman of firsts.

In 1881, she was the first woman to publish research in a major American chemistry journal.

In 1887, she was the first American and the second woman in the entire world to receive a PhD in chemistry.

That same year, Dr. Lloyd became the first female professor at a co-ed institution, UNL.

Not everyone was thrilled to have her there.

Just a year after her arrival, Dr. Lloyd survived an attempt by the chancellor to get rid of her, allegedly because of her Quaker religion.

But UNL faculty supported Dr. Lloyd with a vote of confidence.

Months later, the chancellor was gone and Dr. Lloyd was promoted to full professor.

At UNL, Dr. Lloyd's research helped sugar beets become a major Nebraska crop and made sugar production a viable industry in the state.

Today, Nebraska is sixth in the nation for sugar beet production, an industry that brings in millions to the state economy.

You'd think Dr. Lloyd's life story and professional achievements would be better known, but details were nearly lost to history.

Thankfully, due to a time capsule unearthed at UNL last year, we know more about Dr. Lloyd's pioneering work.

We need pioneers like Mary Sherman Morgan, Alice Ball, and Dr. Rachel Lloyd.

Explorers with grit and determination, though these three didn't always get the glory.

(upbeat music) - Hi helpers!

Do you know that you can be a change maker?

Change makers work to make the world a better place.

Every person can make change by standing up for what is right, like making rules fair for everyone, keeping the earth clean, and helping people in need.

Change makers can be activists, non-profit workers, volunteers, and even kids.

Some famous change makers are Martin Luther King, Jr. who helped make rules fair for people of all skin colors, Jane Goodall who helped protect chimpanzees, and Mulala Yousafzai who helped girls around the world go to school.

Kids can help make the world better too.

We are never too young to be change makers.

- [Narrator] To learn more about Meet the Helpers, visit meetthehelpers.org.

Meet the Helpers is made possible by the Corporation for Public Broadcasting, a private corporation funded by the American people.

- What?

It's that time already?

I've just received word that Dr. Blotch are going to check in with us to see how we're doing with this week's writing challenge, which involves creating menus with tantalizing descriptions.

Are you ready?

Let's go!

(upbeat music) (playful music) - [Dr. Blotch] Morgan?

Hello, Morgan?

- Um, oh, Dr. Blotch, is that you?

- [Robot] Of course, Meg, we're starving!

Are our menus ready yet?

- Well, I can show you what I'm working on right now.

So, I created a menu.

It's called Scoop!

So, it is a bunch of different types of frozen dessert recipes, so it's any ordinary recipe that you would see but then turned into some kind of frozen dessert.

- [Dr. Blotch] Mm, a garlic donut milkshake.

- Ugh, yeah, but that's kind of what I was thinking.

So, I have one item on my menu so far.

It is a sock lint slushie.

So, this slushie is made out of lint and it's cold.

- [Dr. Blotch] At the moment, that sounds like it would be delectable but, what even is a sock lint slushie?

Your menu is missing those details I requested.

- [Robot] Yes yes, the details!

I want to smell the slushie.

- [Dr. Blotch] You know Egan, writers often think through the five senses in order to add more details to their story to help the reader understand their idea.

When you are creating a menu item, you should describe how it smells, feels, tastes, sounds, and looks like.

- Okay, so, let me try this out.

So, for our sock lint slushie, I could write that it smells like socks that have been worn for five days straight.

Keep in mind that I wouldn't eat this myself.

This is for you, Dr. Blotch.

A sock that has been worn for five days straight, that's what it would smell like.

It would feel like soft, fuzzy icicles.

It would taste probably bland but with sharp bursts of ice.

When you bite into it, it sounds like ya know, footsteps walking through fresh snow.

And hm, what am I missing?

Oh, the color.

It's as gray as a day right in the middle of February when the sky is covered with clouds, like very, very gray.

Does that work?

- [Dr. Blotch] Excellent work, Megatron.

We'll begin conducting a sock lint slushie while you and the rest of the 826 Writers get to work on more new dishes.

- [Robot] Bon appetit!

- Thanks Blotch.

(playful music) (upbeat music) (upbeat music) - I really enjoyed visiting Flint, Michigan to meet our friend, James, and learn about his art!

Think about the city you live in.

Why do you think people like visiting your city?

Hmm... Emily, what about you?

- I live in Wayland, Michigan.

I think people like visiting Wayland because they enjoy spending time on the lake right outside of town.

- Hi friends.

My name is Calli and I'm from Cheboygan, Michigan.

Some of my favorite things to do in Cheboygan during the summer are jet skiing, tubing, and paddle boarding with my friends.

I also love to go skiing during the winters and eat donuts during the fall.

(upbeat music) - I declare bankruptcy!

(upbeat music) Hey everyone!

My name is Chris Anderson and I'm at Mammoth Cave National Park.

This park is host to the largest cave system in the entire world and is home to over 130 different species of plants and animals.

It's also home to some amazing geologic formations including stalactites, stalagmites, Egyptian formations, and underground rivers.

But how did this system form?

Time to do a little exploring to find out.

(upbeat music) The rocks around Mammoth Cave is made of limestone that formed around 330 million years ago.

Limestone is a sedimentary rock that's easily dissolved in water, which is how this cave system formed.

Here to tell me exactly how that happened is my friend, Rachel Bosch, a geologist at the University of Cincinnati, who researches how caves form.

Hey Rachel, how you doin'?

- Hi Chris, I'm great.

How are you?

- I'm great.

So, explain to me, how does water create a cave system like the one we're in?

- Well, it takes several steps.

The water is all coming from hundreds of feet up above us when it rains on the surface and as that water comes down through the soil, it's picking up little bits of carbon dioxide.

There are animals in the soil.

The animals are breathing in oxygen and they're breathing out carbon dioxide.

That carbon dioxide combines with the water and makes a weak acid, called carbonic acid.

- Carbonic acid, okay.

- And as the water brings the carbonic acid down through the soil and down into the rocks, it hits the limestone and it reacts with the limestone.

It starts dissolving away the limestone, kinda eating away at it.

Eventually, over time, it erodes out larger and larger passages and it can start bringing in little rocks and those can bang into the sides and make the passages even bigger until over thousands and millions of years, you can get passages as big as the ones that we're in today.

- So, how long has Mammoth Cave been forming?

- Mammoth Cave has been forming for about the past five million years.

- Five million, so it took five million years of water breaking this down to create a cave system this big.

- It did.

So, the passage we're in right now can show us ways in which it's changing.

There's water flowing in through the ceiling right over here.

- Yeah.

- And you can see that that little hole there, it gets larger and larger over time as that water just cuts its way back, almost like a waterfall in the surface.

- It's just like, yeah, so over time, that's gonna move further and further back.

- Mmhm.

- Boy, if you sit here long enough, it really makes you wanna pee.

(laughing) Now, you said as we go down to lower levels, there's water flowing through the cave system as we speak, right?

- Yes.

- Can we go down there and take a look?

- Yeah, let's do that!

- All right, let's do it.

(upbeat music) So Rachel, where are we now?

- So, we are at the shores of River Sticks.

- [Chris] The River Sticks.

- [Rachel] The River Sticks.

It sounds ominous, doesn't it?

- [Chris] It does.

- So, we are in the very lowest level of Mammoth Cave where new passages are forming right now.

So, this is the very youngest area of the cave.

- So, this river here is carving out new parts of the cave as we speak?

- Yes!

- That is crazy!

- Isn't it?

- Yeah!

I mean, it's just like any other river.

It's just hundreds of feet underground.

- Right, it's just, it starts on the surface.

It's a river flowing along the surface that goes into a sinkhole and then, you have the river underground.

So it's just like a surface river but, it's got a roof.

- What is that landscape called and how does that work?

- So it's called a karst landscape and the one big difference you can see between karst and other humid area landscapes is that in other landscapes and ya know, in the west, eastern United States, you'll have water flowing in a lot of streams on the surface feeding the main river.

So you have the main river and you have its tributaries and you can see all these tributaries on the surface, streams and waterfalls.

If you come to then, a karst region, like central Kentucky, like most of Tennessee, a lot of West Virginia, these areas don't have those surface streams.

- So, how does physical weathering, like in this river, help form the cave like this?

- So, the physical weathering part would be the fact that all of these materials in here, we can see, there's a bunch of, this is a pretty big piece of gravel.

- Yeah.

It's got a lot of sand too, like clay.

- Yeah, it's got a lot of sand, silt, clays, all these different green sizes.

These are not dissolving in the cave.

This has traveled from outside of the cave.

- Oh, this came from outside the cave?

- That came from outside the cave.

That's made out of sand stone.

- Oh!

So this isn't limestone like it is here.

It was transported here by the river.

- Yes!

- Oh and I can imagine, if this is tumbling on the bottom of the river, it's gonna knock some other things loose.

- Exactly.

- Interesting, so as millions of years, over a really long time, all these little rocks and pebbles like this help break down other pieces of rock within the cave because the river is carrying them and it's kind of using it to kinda bump and shape and ya know, carve out a whole cave system.

- Right, almost like a sand blaster.

(upbeat music) - Chemical weathering is when air, water, or living things break down rock through a chemical reaction.

Here at Mammoth Cave, most of the chemical weathering is done by water.

That's because when it rains, the water absorbs some carbon dioxide from the atmosphere and the soil, making it slightly acidic.

When that rainwater seeps into the ground and comes in contact with the rock, it reacts with it, breaking it down.

You can reproduce this reaction at home by placing a few drops of acid, like lemon juice or vinegar, on some limestone.

That fizzing you see is gas being given off by the acid as it reacts with the limestone.

Geologists use this test in the field to test the type of rock they're studying.

If the rock fizzes, it's limestone.

Chemical weathering is a big part of how caves like this form.

Slightly acidic water reacting with the rock, breaking it down, and forming a cave.

(upbeat music) Chemical and physical weathering are major factors in how caves are formed and the changing surface of our earth.

Next time you're at Mammoth Cave National Park or next time you're just outside, see if you can identify some examples of physical and chemical weathering.

Before we go, I want to thank Rachel Bosch for being our guide through this cave system and explaining how it formed.

I also want to thank Mammoth Cave National Park for allowing us to tell their story to kids and adults everywhere.

Lastly, I want to thank you for watching.

We'll see you next time on Science Around Cincy.

Hey everyone.

My name is Chris Anderson and I'm at-- - [Cameraman] Actually, back to one.

I zoomed out too early.

(laughing) - Placing a few drops (blubbering)-- (upbeat music) We're done with it.

- Hey mathematicians.

Are you ready for our daily math challenge with Diane?

Today, we'll use our minds to identify the traits of different triangles.

I wonder how many different types of triangles there are.

(upbeat music) - Hey everyone, Diane here.

Today, we are going to be using our wonderful minds to think about how we can identify different characteristics of different triangles.

Before we jump into it, let's talk about what we know about triangles.

Share that with your people and me too.

Ah, yes, it is three-sided.

And it's a closed figure.

Oh, that was another good one!

There are different types, like equilateral.

So, here are some different triangles.

Right now, let's take a little bit of time to look at these triangles.

What do you see they have in common?

Do you notice some things that are very different?

(light guitar music) Ah, so you noticed that some of the triangles have different side lengths.

Yes, I see that with this one here.

I heard someone else say something about the corners of some triangles.

We call these angles and yes, some have very different size angles.

We have three ways to talk about angles for today.

There are more but we'll save them for another time.

A right angle is 90 degrees, like the corner of a paper or an L. We then have an acute angle that's smaller than 90 degrees, like when a cabinet is mostly closed or I'm using my hand as a mouth.

And then, there are obtuse angles that are larger than 90 degrees.

Like when a cabinet is all the way open and I'm looking for my favorite cereal for a snack.

Or when my arm is almost all the way straight.

We'll come back to these triangles, but what I want you to do now is hop up and find a spot where you have some space.

Let's do some math yoga.

That's right.

We're going to be making triangles with our bodies.

You can use your arms, your legs, the floor, a wall, whatever to help you.

(swiping) We are going to start with making any triangle that you want.

I'm going to make one using my lower body as one side, my upper body as a second side and the floor as my third side.

So, go ahead and get into your poses and we're gonna take some deep breaths.

(relaxing music) Be the triangle.

You are the triangle.

All right, do my sides look pretty close to being equal?

They look pretty close to me.

Y'all are doing a great job with your poses.

(swiping) When the sides are all equal, that is called an equilateral triangle.

Equi for equal and lateral for sides.

If we look at the angles of this triangle, what do you notice?

Yeah, I heard several different ideas.

One person said there are three of them.

Someone else said it looks like all of them are less than 90 degrees.

Does anyone remember what those are called?

Say it with me everybody.

Acute angles.

Let's try another triangle pose.

I wanna make a triangle with three different side lengths.

Let's try that out.

You can get creative with this.

Maybe have someone with you help you out.

(swiping) So, I'm gonna stretch out my legs and I'm gonna put my arms like I'm trying to touch my ankle.

You can see deep breaths.

Right here is my triangle.

Hold it just for a little bit.

(light music) All right.

(swiping) Some people made really big differences when they were making their triangles.

Other people made some really small differences like bending their elbow or knee to change the length of the sides.

So, as you can see from the example that I had, I used my stretched out leg, arm, and body to make three different side lengths.

This is called a scalene triangle.

All three sides are different lengths and it could look like this.

Do you notice anything about the angles of this triangle?

Yeah, that's true!

Someone said it looks like one is obtuse and the other two are acute.

That's what I notice too.

We could also call this triangle an obtuse triangle because of that one obtuse angle.

So now, hop up if you're sitting for one final triangle pose.

This time, I want you to try and make a triangle with two sides that are congruent.

I'm going to try it just using one leg, but feel free to get creative again.

All right, here we go.

(light music) Woo, if you lose your balance, that's totally fine.

We make a triangle right here.

All right, deep breath.

Everybody see the triangle?

All right.

Everybody got their pose?

I think you're doing a great job.

Do you think this one was more challenging than the others?

When a triangle has exactly two equal sides, it's called an isosceles triangle.

For this one, I also have a right angle, so it could be called a right triangle too.

From our triangles up here, do you see any that have a right triangle too?

Yeah, this is the one that caught my eye first.

Maybe it's the same one for you.

(swiping) Now that we've gotten our examples for all of our triangles, let's look at the rest of these.

It's neat how even though all of these are all the same triangles, they don't exactly look the same.

Look at that.

From our yoga poses, we have sorted our triangles into groups based on their side lengths.

We talked some about the angle measurements and you'll also get a chance to practice that with some other activities.

Today, we focused on equilateral triangles with three equal sides, isosceles triangles with two equal sides, and scalene triangles with no equal sides.

We also got to see some right angles, acute, and obtuse angles.

Thanks for the yoga class.

Keep practicing those triangle poses.

Bye y'all.

(upbeat music) (pencil scratching) (child laughing) - Welcome to Impact at Home where we practice interrupting prolonged sitting with activity.

I'm Claire and this is Kemper and we're here to help you get moving for the next eight minutes.

You'll be surprised at what these moments of movement can do for you and the rest of your family so you can stay active and healthy at home.

So, go ahead and get up and let's start moving.

For this movement activity, we're going to be focusing on bone health and exercise.

Exercise can help build and maintain strong bones.

So let's go ahead and just start it up with some jumping jacks.

When we're talking about bone health, we have repetitive movements that can really help to keep those bones nice and strong.

Not only do we want to keep our bones strong and getting stronger, but maintaining bone health becomes particularly harder as we get older.

So, the more repetitive movement that you can do now is gonna be amazing.

All right, from here, we're gonna keep that impact going by going into some lateral hops.

I'm gonna show ya.

So, bring those feet together.

We're gonna go back and forth.

Good, get ready to join me.

- Okay.

- We're gonna be here.

Now, what you can do, if popping back and forth is a little bit funky for your ankles, you can just go straight up and down in your regular ankle hop.

Perfect.

Stay with Kemper for those ankle hops.

Join me if you wanna go a little bit more challenging.

Good.

We're gonna be going for a long time today getting that repetitive movement, so stick with us.

Get your breath, here we go.

We've got about 10 more seconds.

Nice.

Five, four, three, two, one, shake it out.

- Whoa!

- Whew, I know!

As well as repetitive movements, we also have resistance-based movements that are going to be really good to maintain bone health.

So, if you have water bottles, soup cans, those are great substitutions for bands or dumb bells.

In this next group of exercises, stick with us to get some up-downs, as well as some modified up-downs and then Kemper is gonna be doing some resistance based training using those water bottles and I'm gonna be doing fast punches left and right.

So, get ready.

We've got those up-downs.

Stick with me for a challenge.

Go with Kemp if you wanna warm up with it a little bit.

Gonna bring the hands to the floor kicking those feet back in three, two, one.

Let's go, hands down.

Kick those feet out, pull up, stand slowly.

Yeah, good.

I see you!

Yes!

You're gettin' the hang of it now.

Good, hands come right down, pop the feet out, pull right in, stand through the feet.

Well done.

We've got two more.

Yes, one more.

All right, quick switch.

I'm gonna be doing those fast left-right.

If you have something that can add weight to your bones, we're gonna be going with Kemper going overhead press.

Nice.

All right, so my arms are startin' to feel a little bit of a burn.

If you are here and those water bottles are starting to feel really heavy, you can follow Kemper and go in alternating one at a time.

All right.

Go for about five more seconds.

We're gonna take up-downs one more time.

Yes, you can!

In three, two, one.

Fast switch, let's go.

Feet back, pull up, stand.

Good job, everybody.

Whew, I knew you can.

This is gonna keep your heart rate up.

All of these different planes of movement, these different directions that I am challenging my body is so good for your bones.

Stand through the feet.

Push, let's get two more.

You've got this, Kemper!

Last one.

And fast left-right.

Right into it, grab those weights.

Grab those dumb bells, bands, water bottles, cans.

You are doing fantastic.

Good.

I'm gonna add one last challenge here with this exercise.

I'm gonna bring those hips down.

- Whoa!

(laughs) - All right, good, good, good.

Keep those arms going.

Five, and four, three, two, one!

And shake it out.

Good job, Kemper.

You're gettin' strong.

All right, last thing we're gonna do is from the ground or from a seated position.

To follow up with different angles of plains of movement, we're not gonna work our obliques which are on the side of our torsos.

They're also incorporated with a lot of core movement.

So, I'm gonna be doing that more challenging movement, straight leg, oblique crunch.

This is where you're really gonna focus in on bending right at the spine, right where the hips and rib cage meet.

Perfect.

I'll show you a couple more times.

Pushing that elbox up to meet the knee.

I'm gonna come back down.

Beautiful.

Kemper is activating those exact same muscles from a seated position.

He's pushing his right elbow to his opposite knee and really squeezing the ribs into the hips.

Amazing.

Hopefully you've been joining us for here.

Let's get a couple more reps. Nice and controlled, use your breath.

Awesome, I know it's hard.

If you're with me on the floor, you can bend those knees.

Good, feel it right here.

Let's go two more.

Nice, last one.

Awesome.

Go ahead and add a little switch.

Disco move on the floor.

We'll do that again, don't worry.

All right, hinge at the hips.

Push elbow to knee and then back down, good.

You look amazing.

I know this is hard, challenging yourself each and every day is so important for your mental health as well as your bone health.

Good, exhale hard, breathe, control.

No matter if you're on that couch or with me, nicely done.

Good, reach, push in.

All right, Kemper, we're gonna finish in a plank position.

- Oh boy.

- You're gonna put your elbows on the couch.

I'm gonna put my elbows on the floor.

We've got two more reps here.

Last one and big switch.

Five seconds to get into it.

Three, two, one.

You're up on your toes.

You're pushing through the elbows.

Watch that tailbone.

Squeeze the tailbone underneath of you.

Like you're zipping up a jacket from your hips all the way up to your neck.

Push down through the elbows.

Lifting through the core, relax your shoulders, relax your neck.

You're gonna be feeling this right where you wear a belt.

Let's go for five, four, three, two, and one.

Great job, everybody.

I hope you enjoyed today's movement break.

Impact at Home is a chance to apply the skills you may have learned in your PE class to improve your health.

To learn more about the health benefits associated with daily movement, visit inpactathome.umich.edu.

Don't forget to fill out your daily log.

We'll see you again during your next workout.

(upbeat music) (light guitar) (upbeat music) - [Narrator] The Indiana Dunes had been a national lake shore since 1966, but they only became a national park on February 15th, 2019.

So, what's in a name?

A national park doesn't receive more funding than a national lake shore, but it's seen as a major upgrade.

- We didn't really realize how important it was gonna be to the public.

The higher profile, the number of people who are coming here, literally the day that the change happened, we started getting emails and phone calls from all over the country saying, "We hear you're a national park.

"We're gonna come visit."

- [Narrator] While there are 419 sites in the national park system, it's the 61 national parks that get the attention and the visitors, like this couple from South Carolina.

- We probably would not have come to the Indiana Dunes National Park if it wasn't a national park.

I would just say it's a bucket list, I think.

- [Narrator] The part stretches from east of Gary to Michigan City, Indiana and within that stretch, there's the Port of Indiana bustling with industry, Indiana Dunes State Park, and several beach towns.

At 15,000 acres, it's less than one percent of the size of Yellowstone, but it's 15 miles of beach, 50 miles of trails, and unparalleled views are all within a two hour drive of millions of potential visitors.

- A lot of folks come just for the beach and they have no idea what's back here.

- [Narrator] Further from the lake front, national park status protects dunes, bogs, and wooded areas, but there are still threats.

A growing number of researchers, park staff, and volunteers are working to better understand the threats and how to lessen them.

The park has a citizen science program where anyone can volunteer to help with certain ongoing research programs.

These volunteers are collecting dragonfly larvae to test for changes in mercury levels.

- It's a wonderful opportunity for people to get involved with scientific research and it's great for the researchers too because when they use the help of volunteers, they can collect a lot more data than they would normally be able to collect if they were doing it on their own or just with a couple graduate students.

- [Narrator] Water levels are another concern because they have changed dramatically.

The Army Corp of Engineers says Lake Michigan rose six inches from May to June.

To an inch short of the historic June high and high water causes erosion.

Erosion damaged one of the park's eight beaches.

The National Parks Conservation Association says erosion claimed 30 feet of beach and parts of access trails at Portage lake front and River Walk on the park's east side.

And on the east end, at the dune known as Mount Baldy, visitors discover how damage to the 123 foot attraction was created by nature and humans alike.

- Feel the wind!

What do you think that wind's doing?

- [Narrator] Visitors running down the dune destroyed plants that held the sand in place.

With the plants gone, the dune began to move and covered up oak trees.

- From the inside out, they decompose and now they have hollow chambers in em.

- [Narrator] The underground hallows make the dune unstable and public access is restricted on Mount Baldy.

The park is now trying to preserve and even restore the dune by planting native vegetation like marram grass to stabilize the sand.

- Our primary mission in the park service and of course, here at Indiana Dunes is resource preservation so that these resources are here for future generations.

We want the public to come in but, if we don't take care of this, there's nothing for them to see.

- [Narrator] Park goers that are often awestruck at the sight of the dunes.

- I think that the response to first seeing the dunes is whoa 'cause they're huge and you're like, "That's not what it should be like.

"This shouldn't be both the desert and the ocean."

But it's' not the ocean or the desert, so killin' it.

(light music) - Well friends, our time has come to an end.

See you next time!

- On the next episode of Extra Credit, make a kite with supplies around your house, learn about teamwork from the Minecraft team, plus a sneak peek at what it's like to work for the NBA.

Check out Extra Credit on the Michigan Learning channel.

- [Narrator] This program is made possible in part by Michigan Department of Education, the state of Michigan, and by viewers like you.

(upbeat music)