- [Narrator] Quality public television is made possible through the financial contributions of viewers like you who invite you to join them in supporting PBS NC.

[piano intro] - Hi, there.

I'm Frank Graff.

Why are great white sharks visiting North Carolina's coast?

Shipwrecks, as you've never seen them, and creating ultra dark materials.

We'll show you things you've never seen before, next on "Sci NC."

- [Announcer] Funding for "Sci NC" is provided by the North Carolina Department of Natural and Cultural Resources.

[gentle music] ♪ - Hi, again, and welcome to "Sci NC."

There is likely no group of scientists that have done more to raise our awareness and our knowledge of great white sharks than Ocearch.

Their combination of technological innovation and use of social media have provided amazing insights.

Well, now the Ocearch team is turning its attention to North Carolina's coast.

Science producer Rossie Izlar explains what they want to understand.

- [Rossie] It's springtime off the coast of North Carolina and the Ocearch team is trying to solve one of the great mysteries of the great white sharks: Where they mate.

- We're talking about an ancient secret, right?

This is a 400 million year old secret that the ocean is deciding whether or not it wants to reveal to us or not.

- [Rossie] It's a daunting task in the face of North Carolina's turbulent seas.

- This time of year in this area when these big mature animals are here, the weather's tough.

It's super dynamic.

You got the Gulf stream colliding with Hatteras just north of us.

It's windy and maybe you're able to work one in four days across a 22 to 25 day trip and then you have to catch the right shark.

This isn't just a test, a test of endurance, a test of tenacity, a test of stamina.

If it was easy, it'd have been done by now.

- [Rossie] Since 2012, Ocearch has tagged 84 sharks and mapped their range across the world using a gentle catch and release method that leaves the animal unharmed and outfitted with a tracker, discovering where their nurseries are, where they feed and forage, and this is the last piece of the puzzle.

The team suspects that sharks are meeting off the coast of North Carolina because they've seen adults converging here.

- And then all of a sudden the males just continue their sort of dumb male thing of going back and forth.

But then, the females, all of a sudden, shoot offshore from here and they make these enormous loops out into the open ocean.

I mean way past Bermuda, all the way out to what's called the Mid-Atlantic Ridge.

Why would they do that?

And why just the mature adult females?

Well, we think that the best explanation is that's when they're pregnant and they're getting away from the rest of the population, getting away from any more harassment by males.

- [Rossie] Knowing where great white sharks mate is important.

- So, if we can understand the entire life of a white shark, which might run 80 years from birth to old age and death, then we can know where those critical places are in each step of the way.

So these animals have been severely depleted over the last three or four decades and now they're making a return and our work is laying out a path for that return to abundance and also showing us where the critical habitats are where these animals face threats that we need to take into consideration.

- [Rossie] In the more than a hundred shark-centered movies produced since "Jaws," 97% of them featured sharks threatening humans and the antagonist in most of the films have been great white sharks.

Despite our anxiety around sharks, they have more to fear from us than we have from them.

Overfishing and by catch, or getting caught accidentally in fishing nets, are the biggest threats to great white sharks globally and we're discovering that their presence in the ocean is crucial.

- And what we see when we lose our large sharks is we see the entire food web collapse.

Things like seals and squid and other things that sharks really keep under control, begin to wipe out all our fry, all our baby fish, and the seals will wipe out all the stripers, all the cod, all the red fish and so, with sharks and our large sharks at such low levels, we were in a situation where, if we don't find out how to bring them back, how to manage them back, we were gonna really struggle to deliver a working abundant ocean to the future and that's why the white shark things within their life history that are hugely important to make sure they return because they have a lot of challenges, right?

These animals aren't sexually mature till they're 20.

So they have to live 20 years just to replace themselves.

- [Rossie] And that's why Ocearch has crossed the globe tracking great white sharks, revealing the secrets of how and where they spend their lives.

It's not just Ocearch scientists that use this data.

At least 45 scientists rely on samples from Ocearch's team to conduct critical shark research.

- We have to touch far less sharks than if all those 45 scientists were to go out and working on the white shark, for example, and have to collect the sample size they need.

It would be potentially 45 times bigger sample size.

So it's a beautiful thing.

- [Rossie] The team found two males with elevated sperm counts off the coast of North Carolina, but they want a larger sample size to confirm this last life cycle mystery.

So they'll be back to brave the North Carolina weather.

- Now we're really ocean people and we were trying to get involved with things that help make sure our kids could go out and see an ocean full of fish.

Our mission is to return our world's oceans to abundance.

It just happens that one of the primary paths to abundance happens to go through the white shark, our apex predator and the balance keeper.

- [Rossie] Wanna take a deeper dive on current science topics?

Check out our weekly science blog.

- Staying out at sea, North Carolina's coast is known as the graveyard of the Atlantic because the combination of shifting sands and currents as well as wartime activities has sent hundreds of ships to the bottom.

Scientists are now doing a new look at those wrecks.

Producer Rossie Izlar has that story as well.

[gentle music] - [Rossie] Beneath the waters of North Carolina's coast, a massive graveyard stretches from Currituck to Bogue Banks.

More than 5,000 ships have met their end here and those are just the ones we know about.

The reason this region is so perilous has to do with the ever-changing shoals rising from the sea floor.

It's basically a system of underwater dunes that ships can easily run into.

Add piracy and three maritime wars and it's understandable that we call this region the Graveyard of the Atlantic.

- We have very rapid currents fed by the Gulf Stream.

We have shallowing waters, dangerous waters around the capes made up of sand shoals, and we have dynamic storms that pop up at a moment's notice and wreak havoc on the seagoing vessels.

- [Rossie] But there's new life thriving on these shipwrecks.

- So, when we first get eyes underwater, we're descending down the water column.

It's blue, sometimes there's not much light if we're really deep.

We reach the bottom, that sandy bottom, and start to head towards the ship and, on our way there, we often see signs that mean we're approaching the shipwreck.

We see big silvery schooling jacks dart through the field of view of the camera and, once we've reached the shipwreck itself, it's just incredible.

The amount of fish sometimes on these wrecks is so great that it obscures us from seeing the wreck structure itself.

I was just struck by how alive these wrecks were with marine life.

It was absolutely stunning.

[gentle music continues] ♪ - [Rossie] A team from NOAA set out to explore some of these historic shipwrecks.

They came equipped with sonar and remotely operated vehicles, loaded with 4k cameras, to see just how much life these wrecks support and it wasn't easy getting down here.

- The shipwrecks sunk for a reason.

They either sunk during war time or they sunk because of challenges of ocean storms and the seabed and shallow waters and then we encountered those same challenges, except for the war time effects.

[gentle music continues] - [Rossie] But the effort paid off.

Researchers glimpsed unprecedented views of these unique habitats and collected valuable data on how the ships are being used by marine life.

[gentle music continues] - The imaging sonar is a really cool tool.

It transmits sound through the water at very high frequencies.

It allows us to image and detect things almost like an acoustic camera.

So we're transmitting high frequency sound over 10 times a second up to 50 meters away from the ROV or 150 feet and outward about 140 degrees or almost a half circle.

This enhances our ability to detect animals that are using the shipwreck far behind what the camera is able to see and it produces what it is in essence a video, an image of fish moving.

We can sense and detect fish moving around the shipwreck, forming tight schools, or individual sharks swimming through the water column.

[gentle music continues] ♪ Even though we can image very large schools and give us an idea of the quantity of fish or the numbers of fish, we need to deploy something like an ROV in order to capture the images in the video in high definition to help us identify them to species.

[gentle music continues] ♪ - [Avery] These sites really are forming oases for marine life and one of the things that we think may be happening is that these shipwrecks are forming islands, almost stepping stones if you will, that some of these animals can use as they move from place to place, almost like a rest stop.

- [Rossie] As climate change continues to warm ocean waters, more species may be using these rest stops.

- One of the things that the observations we are able to make on this mission will help us understand is what the current snapshot is, what types of fish are living on these shipwrecks, and we can continue to monitor these shipwrecks into the future to understand how that may change over time.

Being able to get eyes underwater on these shipwrecks is pretty rare.

A lot of circumstances have to align for us to get a large research vessel with this technological equipment out into the ocean and then 200 to 800 feet underwater to observe the history and the ecology and that fusion.

- From discovering sharks and shipwrecks to discovering new adventures, producer Evan Howell introduces us to University of North Carolina professor Jim Kitchen, who has visited all 193 United Nations-recognized countries and more.

[upbeat surf rock music] - [Evan] The year was 1969 and it was officially the end of the space race.

That was also the year when Americans landed on the moon, a period that captured the imaginations and dreams of most everyone, including a very young Jim Kitchen.

- One of my earliest childhood memories was sitting in my mom's lap watching the Apollo space launch.

- [Jack] Five, four, three, two, one, zero.

All engine running, lift off.

We have a lift off!

- And I was hooked.

I wanted to be an astronaut.

I saw this rocket lift up toward the heavens and shook the earth and lit up the sky and I just wanted to be an astronaut.

[upbeat music] But I came to college at UNC and wasn't smart enough to become an astronaut so I became an entrepreneur and began promoting low earth orbit space trips 'cause I wanted to go to space, but that didn't happen either.

I didn't sell enough trips to go to space and then Challenger happened and so I kept the dream alive.

My parents were public school teachers and so June, July, and August, they put the kids in the back of the wood-paneled station wagon and off we'd go from South Florida to Washington State.

They were explorers.

They were adventures.

Wantin' to go to space, wantin' to be an astronaut was just normal.

- [Evan] Over the next 30 years, Kitchen then traveled to the 193 United Nations-recognized countries.

- After walking across this planet, it was my goal to see that whole spectacle from space and so I dubbed space 194.

- [Evan] And, in March 2022, he got his chance as a passenger on the Blue Origin rocket, the Blue Shepherd.

- So it was four days of intense training.

What they were preparing us for was launch day activities.

So what to expect from the time we woke up until the time after we landed.

We had a zero G plan, what we would do once we get to space.

They also wanted us to learn how to get in and out of a seat and buckle our seat belts, a five point harness, which is a lot more difficult than you would imagine.

So we had a 45 minute delay.

At the countdown, when the clock started, ten, nine, eight, it was very emotional because I realized that this 50 year journey to space was actually gonna happen.

- [Man] Seven, six, five, four, commanded to start.

Go.

[fire crackles] - It felt like being in an electric car and accelerating from zero to a hundred in a half a second and then going from a hundred to 500 miles an hour in another few seconds and my face was just, it was wow!

It was all I could take and I just remember thinking, "Hang on, hang on."

I did not wanna be that guy that passed out, went to space and everyone was like, "How was it?"

And then I was like, "Well, I don't remember."

So I was just hangin' on for dear life.

- [Evan] Only the fourth Blue Origin rocket to haul humans to space, the booster rocket is a 60 foot tall reusable rocket traveling at over 3000 miles an hour to get the passengers where they want to be.

- We get to MECO.

MECO is main engine cutoff and then separation happens right after we're all rooting for separation.

We wanna hear that large thud that everyone's heard so much about.

Why?

Because, if it doesn't separate, everything's flying back to Earth all together in one piece and, yeah.

- [Evan] Booster rocket did separate and returned by itself at so-called launch site one in Texas.

The capsule then reached what's known as a Karman line, officially recognized as where space begins.

That's when the capsule coasted upward to an altitude of just over 66 miles.

- And so I looked at my own window behind me and there it was: The Earth, about one quarter of the window, and then three quarters of that four foot window was the darkest, most eternal, the blackest of black, completely void of light, and I was just mesmerized by the whole scene.

Having seen space in a book or in a movie was not at all the same as seein' it live.

We were just all completely dumbfounded and it was just one of those mind numbing experiences.

For me, I called it an out of body experience.

Just seeing that it was like nothing I had ever or will ever experience.

It's been emotional since I've gotten back.

I was very emotional when I landed.

Why?

Because, personally, it was a 50 year odyssey to get to space, but also I'm a teacher and, for me, this whole notion of anything is possible, pushing through boundaries, and keeping those dreams alive was really important for me to experience.

But, to be able to to be able to share that with my students, having lived that, was what was most meaningful.

- [Evan] And here's an update to our story.

A couple of weeks after returning to Earth, Jim Kitchen added a few more miles to his travel adventures.

Miles probably as spectacular as that trip to space.

Kitchen visited the deepest point on earth.

It's about 200 miles off the island of Guam in the Pacific Ocean.

That deep point is named Challenger Deep.

It is in the Mariana Trench, seven miles beneath the ocean's surface.

It took the submersible that Kitchen and a pilot were we're riding in about four hours to reach Challenger Deep.

There is no light, no oxygen, freezing temperatures, and crushing pressures.

But Kitchen says he was amazed to still see life.

Tiny anthropods, creatures with an exoskeleton, and bacterial mats which are chemosynthetic.

That means they make food from chemicals in sea water, no light needed.

He said, "If you've ever seen dark, you haven't seen that dark."

Speaking of dark, this next story is a dark story.

Well, not dark in the sense of the dark side or something bad, it's about the color black.

In fact, here's Melissa Salpietra with a quick review of just how we see colors, white and black and everything in between.

- [Melissa] Consider a rainbow.

Although it may seem magical, what you are really seeing is an incredibly accurate visual representation of the electromagnetic spectrum.

Each of those colors your eyes detect are an example of different wavelengths and different frequencies of energy being transferred from the sun, through the vacuum of space, refracting through the particles in the atmosphere, entering your eye, and being processed by your brain.

And, incredibly, the light we see is only a tiny fraction of the electromagnetic energy traveling all around and even through us.

Humans can only detect wavelengths between 700 nanometers and 400 nanometers with our naked eyes.

These wavelengths are what we call visible light.

All other wavelengths of electromagnetic radiation are invisible to us.

We can't see it even though it's there.

So, although a rainbow may seem magical, the two little energy detectors in your head deserve some credit too.

- [Announcer] Do you want to explore more cool science facts and beautiful images of North Carolina?

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- So, remember, white light is composed of all the colors of the rainbow.

We see colors because objects reflect some colors and absorb all the others and we perceive the color black when all the colors of the spectrum are absorbed.

Then, there's ultra dark materials.

Producer Rossie Izlar shows us black in a whole new light.

[gentle music] - [Rossie] Some animals have perfected the art of being black.

[gentle music continues] - There's a really beautiful bird called the superb bird-of-paradise that shows up on all the nature shows when it does its mating dance and spreads out its wings into a big, black oval and then has a blue smiley face on it [gentle music continues] and the blue smiley face shows up really beautifully because the background is just like looking into a hole.

- [Narrator] These butterfly species use contrast to attract mates too and their scales can be 10 to a hundred times blacker than charcoal.

Deep ocean dwelling fish use their ultra black scales to hide from both predators and prey.

Researchers at Duke University are studying these ultra black creatures because, it turns out, humans have found uses for things that are super black too, like coating the insides of telescopes so they can absorb enough sunlight to get us images like this.

[gentle music continues] Our phones are also coated with black.

- Your phone is an extremely black surface so that you can use it in the daytime and this is also why, if you leave an iPhone out in the sun, it gets so hot that it shuts down because every single piece of light that hits that iPhone goes straight in.

[upbeat electronic music] - [Rossie] So scientists are trying to understand how these animals are making themselves so black so that maybe humans can learn from them.

[upbeat electronic music continues] To make something ultra black, you need it to absorb light.

- You not only have to absorb the light, you have to bounce it around, what we call scatter.

You need to have a whole lot of scattering.

If you remember, back in the day, they would have velvet Elvis paintings and the reason velvet is black is because it's got all these little black hairs that stick up and, as the light comes in, the light bounces around between the hairs.

It can't just bounce back out and, every time it hits a little black hair, it loses a little bit more of itself and so, the fish and the butterflies that do this, they do this by creating structures that have a huge amount of light bouncing around in a very, very small space.

- [Rossie] Here's what an ultra black butterfly scale looks like under an electron microscope.

- [Sonke] The butterflies do another structure that sort of sucks light down these holes and then traps 'em in a little catacomb cave where it bounces around inside the cave and, again, can't find its way back out and the neat thing about it is they're doing it in ways that are a lot more sturdy than what we do technologically.

[gentle music] ♪ - [Rossie] Today, one of the blackest substances in existence is called Vantablack.

It's made from microscopic structures called carbon nanotubes which trap light and they are very delicate.

- So, if you push down on a piece of Vantablack, it's no longer that black forever.

But these fish and these butterflies, I mean, they exist in the world.

The fish are swimming around.

They're likely not bumping into anything but they have to deal with currents and movements of the body and, butterflies, they're running into things.

They're getting rained on.

They're living their entire life with these scales and clearly they hold up and they're still just as black.

- [Rossie] That's why the team is studying ultra black creatures.

Alex created a mathematical model to figure out which parts of these elaborate structures matter most for absorbing light.

That way, engineers can replicate it for materials we need to be super black because, right now, those fragile carbon nanotubes are the best we've got.

[gentle music continues] - [Sonke] The thing that animals are incredibly good at we're very bad at.

We're good at building things down to about a millimeter or so in size, but it's really hard to build things that are much smaller than that and cells are incredibly good.

In fact, that's where they like to build the most is to build structures that are the thousandths of a millimeter kind of size and they can build these just beautiful arrays that do absolute magic with light and so on.

- [Announcer] Hey, parents, teachers and homeschoolers, looking for lesson plans?

You'll find free interactive ones about all types of science covered by "Sci NC" online.

- And that's it for "Sci NC" for this week.

Be sure to check us out online.

I'm Frank Graff, thanks for watching.

[gentle music] ♪ - [Announcer] Funding for "Sci NC" is provided by the North Carolina Department of Natural and Cultural Resources.

[gentle music] ♪