All language subtitles for NOVA.S51E17.Building.Stuff.Change.It.1080p.WEB.h264-BAE_track3_[eng]

NARRATOR:
We live in a built world.

Engineering and technology,

built upon
innovations and inventions,

stretching back
thousands of years.

Some of our creations,
like machines,

boost our bodies' abilities.

Others help us reach
outside our comfort zones.

We have left an indelible mark
on the planet.

And now the time has come
to use our skills

to make a better world.

WORKER:
...two, three, lower.

NARRATOR:
Like inventing a new way
to fly,

electrically.

Or a device that can smell...

ANN PERSON:
I get very excited
when technology works.

NARRATOR:
...to save food
from going to waste.

THARINDU MADDUMA:
Food waste is
enormous global problem.

NARRATOR:
Creating a machine...
RESEARCHER: Rob, I'm going in.

NARRATOR:
...to heal coral reefs.

ARAN MOONEY:
How do we fix
the environment that's

sort of dying in front of us?

NARRATOR:
Or even combining
a traditional work of art...

LEWIS STETSON ROWLES:
We see this amazing
opportunity to use pottery.

NARRATOR:
...with modern chemistry...

NAVID SALEH:
Could you actually make
something like that?

Do you have something similar?

NARRATOR:
...to provide
clean drinking water.

I made a shape similar to that.

NARRATOR:
"Building Stuff: Change It!"

Right now, on "NOVA."

♪ ♪

NARRATOR:
Human beings have been

changing our surroundings
for thousands of years.

The signs are written
on the land itself.

We're builders and makers.

And the evidence
is plain to see.

ADAM STELTZNER:
Our whole lives are constructed.

We live in the modern world
in a very altered environment.

And all of that alteration

starts and finishes
with engineering.

ANDREA ARMANI:
Engineering can transform
a community by

bringing power,
bringing water, growing food.

DEB CHACHRA:
Taking sewage away, the power
grid, telecommunications,

these are all
engineering systems

that are not about
making any one of us

smarter or stronger or faster,
but making us, collectively,

have more agency
and more capacity.

NARRATOR:
But building the modern world

has come with steep costs

and changes to more
than just the land,

like altering the chemical
composition of our atmosphere.

But now there's a new generation

that wants to engineer
a cleaner planet.

So, as an engineer,

when you see the world as it is,
you begin to think,

"How could we make it better?"

So that's our job,
to take the world as it is

and make it better.

Everyone's
engineering background,

it comes from
that purpose of saying,

"I want to solve a problem
that just changes the world."

NARRATOR:
One daunting challenge
we face today

is to reduce
the carbon emissions

caused by burning fossil fuels.

Electrifying transportation
offers some hope.

On the ground,
cars, buses, trucks

and trains are
gradually making the switch.

But what about in the air?

Is there a way to go green
in flight?

At Joby Aviation
in Marina, California,

engineers think so.

They're testing
a new kind of aircraft.

WILSON:
So, today,

uh, Joby's flight test team

is putting the aircraft
through its paces,

flying range and
endurance missions.

like a helicopter,
able to take off vertically,

but also, like an airplane,

able to fly horizontally
at high speeds.

And it's completely electric.

ARMANI:
The challenge is, you know,

how do we make
a personal helicopter?

How do we make them sustainable?

Right, we don't want to bring
more jet fuel into the world.

WILSON:
It is routine for us to fly

three times a day, cruising
around at about 100 knots.

NARRATOR:
Joby's ultimate dream

is to deploy the aircraft
in cities around the world

as flying taxis,

reducing congestion
on the ground.

Today they're in
the final testing stages

of their latest prototype.

But despite promising results,

they're not taking chances
with humans on this round.

WILSON:
There's actually nobody on board

the aircraft
while it's in flight.

The pilots are simply
sat on the ground

in the ground control station,
flying the aircraft remotely.

NARRATOR:
Technically, it's
known as an EVTOL,

Electric Vertical
Take Off and Landing.

But it's also capable
of level, forward flight.

As we're going through our
airspeed expansion,

we are testing a,
a certain airspeed,

performing a bunch of tests

to make sure
our aircraft is stable,

and then expanding into
different airspeed regimes

all the way
to fully wing-borne flights.

NARRATOR:
This day's testing
is winding down.

A sudden tilt on touchdown
is quickly corrected

by the remote pilot.

Something to tweak
for future flights.

WILSON:
Our analysts look
at the data after the flight

to make sure that
the aircraft is performing

exactly as we expect it to.

NARRATOR:
As Joby engineers work
to realize their dream,

significant engineering
challenges remain

before regular passenger flights
become a reality.

DARAIO:
As you're trying to develop
transportation devices,

you really need to understand
the environment

in which these systems
need to operate

and iterate the
engineering design,

NARRATOR:
Today, it's not uncommon to see
helicopters in city skies.

But they have drawbacks.

They're noisy, the learning
curve to fly them is steep,

they have limited forward speed,
and they burn fossil fuels.

Joby's design is an attempt to
address all of those problems.

VALERO-CUEVAS:
You have identified a problem.

Can you make an airplane

that uses propellers like
a helicopter

but doesn't have
that noise?

Well, you've dreamt it up.

The question is,

how do you actually
bring it into existence?

WORKER:
All right,

one, two, three, lower.

NARRATOR:
One of the biggest challenges

has been to invent
a new propulsion system.

The idea was to design a vehicle
for four passengers and a pilot

that can rise straight
off the ground

and then somehow transition
to fly like an airplane.

Joby's solution--
six electric motors

that can individually pivot,

propelling the vehicle
up to 200 miles per hour,

eliminating fossil fuels
and reducing noise,

a critical improvement

if they have any hope
of widespread adoption.

That's what gives the aircraft
its unusual profile.

Six smaller propellers

that are quieter than
a single helicopter blade.

But because they're small,

everything depended on finding
the right propeller shape,

a surprisingly
complicated problem,

part art and part science,

with much of the know-how

handed down since the early
pioneers of powered flight.

These propellers may seem
wholly modern.

But if we trace their evolution,

we can see clear connections
to the past.

Leonardo da Vinci's notebooks

contain one of the most famous
early conceptualizations

of a device
resembling the modern propeller.

Da Vinci, in turn,
may have been inspired by

the Greek philosopher Archimedes
and his screw-shaped water pump,

or even by nature.

Certain plants and seeds,
like the maple and sycamore,

have evolved similar shapes.

When they fall from trees,
they look and work

remarkably
like helicopter blades.

At Joby, the design team
is looking for the best shape

to balance power and noise.

We went through a lot
of experimentation

with actual propeller,
uh, prototypes.

to really understand
this phenomenon.

NARRATOR:
To reduce noise, it helps to
understand what causes it.

As each propeller blade
slices through the air,

it creates pressure vibrations.

The strength of those vibrations

depends in turn
on a propeller's shape,

how fast it spins

and the number of blades.

MIKIC:
So we iterated
with a number of designs.

We took blades with
a lot of blade area

and then much thinner blades
and, uh, trying to see

how that results
in acoustic generation.

These propellers
are turning much slower

than traditional
helicopter blades.

We varied the shape,
a lot of experimentation.

I think
this trial and error system

is something that allows us
to ever more refine design,

produce and, uh, test,
which, in multiple iterations,

allows us to arrive to,
uh, to optimal solutions.

NARRATOR:
The company has tested
several blade shapes,

hoping to find
the best combination

of efficiency, lightness
and durability.

To test
each new propeller design,

the company has built
a large circular track

in an old quarry
near Santa Cruz.

MIKIC:
In quarry, we have
what we call "The Whirlybird,"

which is a track kind of like
a roller coaster track

that goes around in circles.

And we have to test
this propeller

not only in hover conditions,
but through all the conditions

that it experienced
through transition

as well as forward flight.

NARRATOR:
On the track,

they test each iteration
of the propeller

for durability and blade design,

as well as for noise.

MIKIC:
And then we adjust the angle
of the propeller,

the speed of the propeller,

the variable pitch on it

to see how it operates
in different regimes of flight

that the real airplane
would experience.

And we can do this
for hours on end,

days on end, uh,
to see how the system performs.

ARMANI:
The design of a propeller

is a very theoretically
heavy lift.

However, at the end of the day,
experimental results rule.

And their ability
to build that huge test ring

to really, you know, compare
their experimental results

with the,
the theoretical predictions

are really
what allowed them to advance

and push
their entire plane forward.

NARRATOR:
Ultimately, they discovered
that their original design,

which was wider,

actually performed better than
subsequent slimmer designs.

The greater surface area
allowed them to slow down

the propeller's rotation speed,

reducing noise while
meeting power requirements.

MIKIC:
When you do the experiments,

you realize you're going down

the wrong path, then you
start to go back and see,

like, well, why is
the thing that I tried to do

that makes things better
actually worse?

So you challenge
your own assumptions.

DARAIO:
Challenging assumption
is something that

is an essential component
in engineering.

Being able to harvest the
advances of divergent thinking

and creative thinking

is something that, in the end,

promotes innovation
and allows us

to advance technology
much faster.

NARRATOR:
A change to the shape
of the propeller

helps with
the nature of turbulence

generated by the blade.

Exactly how they did it,

a Joby representative said,
is a trade secret.

But the result is a vehicle
that the company says

produces 100 times less acoustic
power than a helicopter.

Eventually, they're hoping
to expand their test program

to include passengers

and move toward
full certification

from the
Federal Aviation Administration.

DIDIER PAPADOPOULOS:
Safety is non-negotiable.

Look, I'm gonna put my kids on
these airplanes,

and so this is, this is
close to me,

just as it is close to
everybody else.

routinely with an aircraft
like this,

and be able to do it
relatively low cost

and super available
to the masses, is so exciting.

NARRATOR:
Today, air travel accounts
for an estimated 10%

of the carbon produced
by all transportation.

It's this kind of
experimentation

that could lead to
bigger changes in air travel.

Electrifying aviation
is one of the hardest

engineering challenges we face.

But not every problem requires
such a difficult solution.

When it comes to finding ways
to reduce carbon emissions,

there is some
lower-hanging fruit.

Over thousands of years,

we've gotten
more and more efficient

at growing food
for an ever-growing population.

But the road from farm to table
can be long and wasteful.

Globally,
a third of all crops go bad

before they reach the table.

And with food production
accounting for about 30%

of global
greenhouse gas emissions,

reducing food waste
could be one solution

to our climate problem.

At least, that's the idea behind
a Norwegian rot-sniffing robot.

The BAMA food warehouse
in Oslo, Norway.

NARRATOR:
Anne Person is the director
of quality assurance.

We get about 2,000 pallets

in here every night.

NARRATOR:
The produce comes in
from 80 countries.

They're being scanned here.

And then they go straight
to the quality control tower.

This is the first control
that is being done

when it comes to Norway.

NARRATOR:
Inspectors screen the produce

for spoilage, as best they can,
before sending it

to the supermarket.

The problem is we don't have
very much time

to inspect the
pallets.

It's maximum
60 seconds.

we are only able to control
the two upper layers, maximum.

NARRATOR:
That means,
even with experience,

visual inspection
only goes so far.

Inevitably, some spoiled produce
goes undetected

and gets shipped along
with the rest of the produce

all over Norway
to local supermarkets.

PERSON:
So our question was,

how can we check
the whole pallets?

So that's when we started
to look at the new technology.

The goal is increased freshness
and reduced food waste.

If you can detect spoilage
earlier in the value chain,

we are also able to do more

with the products
that we might reject.

We can sort them,
we can give them to food banks.

NARRATOR:
BAMA connected with Tunable,
a small tech company in Oslo,

inventors of an artificial nose,

or machine olfaction device,

that is already
in use monitoring

the amount of greenhouse gasses

emitted by container ships.

Tharindu Madduma is Tunable's
business development manager.

MADDUMA:
BAMA came to us.

They explained
that they had this problem

of determining the quality
of the fruits and vegetables,

being able to do it at
a large scale

and being accurate.

VALERO-CUEVAS:
There's a long history

of inventions

that allow us to extend
our senses.

So we've done that
for sight.

We've done that for hearing.

MADDUMA:
So, we have microscopes,
we have hearing aid,

but smell is still a sense

that we haven't digitalized.

And that's what we're doing.

NARRATOR:
Kristian Hovet
is Tunable's C.E.O.

HOVET:
When you take a breath,

you're doing a
multi-gas analysis.

You're pulling in
molecules,

and those molecules are detected
by your nose,

to tell you
what you're smelling.

NARRATOR:
The challenge for Tunable

was to take their existing
analyzer for emission analysis

and increase its sensitivity

without making the device
too big and cumbersome

to be useful
on a warehouse floor.

So why use smell?

Our noses are
sensitive detectors,

able to identify a wide variety

of chemicals in the air,
even at low concentrations.

Airborne molecules
can also potentially reveal

what's hidden in the pallets.

These molecules tell
a chemical story

of fruits and vegetables
as they rot.

But the device would have to be
far more sensitive

than a human nose,
and able to detect spoilage

more reliably than a human eye.

Produce, like all living things,

decays after death

as microbes consume dead cells,

releasing
volatile organic compounds.

In theory, the team should be
able to tune their machine

to recognize those molecules.

We knew that we could look
at complex gasses.

We redesigned emission analyzer,
and then we started testing.

NARRATOR:
Eivind Jülke Røer

is the lead engineer on
the Tunable e-nose project.

RØER:
So now I'm going
to measure fresh grapes

and then some spoiled grapes.

See our e-nose can smell
the difference.

I'll start with collecting

a sample from
the ambient air

as a baseline for
the measurement.

And the noise you can hear now
is actually the compressor pump

pulling air, uh,
into the analyzer.

So now I'm going to take a
sample from the fresh grapes

to see if there is anything
present there.

NARRATOR:
The probe pulls in air

and then compresses it

by a factor of five,

which increases
the density of the sample

and makes molecules
easier to detect.

Next, infrared light
shines through the sample.

The light then passes
through a chip

that sorts different types
of molecules

based on
the specific wavelengths

of light they absorb,

which ultimately
allows the analyzer

and accompanying software
to reliably detect

the presence and concentration

of molecules
that signal spoilage

with extreme sensitivity.

RØER:
The reading I got now

doesn't really show
any molecules present at all

compared to ambient air,

which is more or less what I
would expect from fresh fruit.

(machine whirring)

So now I'm going
to take a sample

for the, um, spoiled grapes.

We see a clear difference.

We see up to 12% absorption

at ethanol wavelength,
which is a good indication

that we actually smell
the rotten grapes.

So, uh, this looks
really promising.

HOVET:
The fumes we were able
to collect,

we were able to see the,
the kind of the signatures.

NARRATOR:
The engineers then tested

different kinds of
fruits and vegetables

as they decayed, building up a
database of chemical profiles.

HOVET:
We saw a tomato was different,
somewhat, from a banana.

Grapes were different
from avocado, for example.

And we thought, well,
this must be interesting.

(laughs)

(compressed air can sprays)

NARRATOR:
Thor Bakke

is the founder and Chief
Technology Officer of Tunable.

He's been working with
microelectromechanical systems

for over 30 years.

BAKKE:
Tunable is a component,
uh, inside our analyzers.

That's the Tunable filter.

It's used to change the
wavelength of light

so we can scan the wavelength
and do spectroscopy.

Spectroscopy is
very much like, uh,

tuning a radio to find
a particular station.

The gasses are separated
in the infrared spectrum,

just like radio stations.

And then you can basically
detect each one of them.

So that's where the word
Tunable comes from.

NARRATOR:
After extensive fine tuning
in the lab,

it's time for the very first
field test in the warehouse.

STELTZNER:
Sometimes you can't learn

about all of the variables

that will be involved
in an engineered system

sitting on a desk

with a pen and paper or at
a computer screen.

You need to go out
into the field.

and see how it interacts,
learn from that, make changes,

and move forward.

RØER:
Now I'm capturing; I'm in there.

Now I'm ready to do
the measurement on the grapes.

NARRATOR:
Eivind watches the screen,

waiting to see
the telltale grape waveform.

But the pump just whirrs away.

And eventually he gives up.

Uh, I don't really know
what happened here.

Uh...

For some reason, um,
the results wasn't as expected.

NARRATOR:
The first time
definitely wasn't the charm.

Murphy's law.

Yeah.

HOVET:
We know that it works in a
laboratory environment.

So the big thing now

is showing that
it actually works...

(chuckling):
...in real life, and as you see,
there's been some challenges.

CHACHRA:
We tend to think of failure
as a bad thing, right?

That something that is not
supposed to happen, happens.

But if you're doing
anything new,

failure is an integral
part of the process.

And the reason for that
is because we can't

in the real world
until we try them.

NARRATOR:
Turns out
the warehouse temperature,

a chilly 41 degrees Fahrenheit,

affected the test result.

HOVET:
The cold part.

We did know that
it was cold in that area,

but did we take it
on account enough?

No, we didn't.

We should, of course,
have thought about that.

But, uh, but that's
the kind of the learning,

that's the process.

NARRATOR:
Back in the lab,

the Tunable team
recalibrated their chip

to account for
the BAMA warehouse temperature.

They also adjusted the design

to include the pumps
that compress the sample,

increasing the density
of the gas

to compensate for
the lower metabolic rate

of the food in
the refrigerated environment.

RØER:
It will be
really interesting to see

if the alterations
we have, uh, made,

will actually do
the difference in the field.

NARRATOR:
Eivind is back with the latest
iteration of the e-nose.

Further testing in the lab

showed that,
even with the changes,

the machine needs time
to adjust to the conditions

in the warehouse.

RØER:
Now, I'll let the instrument
stay here for the night

to reach a steady temperature,

and then we'll do
measurements tomorrow.

♪ ♪

Well, after a long cold night,

the system
should be ready to go.

(machine whirring)

Now we see absorption of light

at more or less 9.5,
ten microns,

which, um, indicate
ethanol being present.

This really shows that
our new chip is working

in this real environment.

NARRATOR:
Eivind uses the e-nose

to sample the air
from various locations

on the entire pallet stack.

RØER:
Actually, we see a spike at the
ethanol absorption wavelength,

so that might be something.

NARRATOR:
They've taken an important step.

A successful real-world test

of the newest version
of the Tunable e-nose.

I'm not the most
excited guy, but, um...

(giggles)

...this is, uh,
this is exciting.

(e-nose humming)

I expected it,
although you never know.

It's a big win.

I get very excited when
technology works.

NARRATOR:
Still, there is work ahead to
make the technology viable

and, most importantly, scalable.

MADUMMA:
We hope that we can
make them more efficient.

Food waste is enormous global
problem.

So if we can be a part
of the solution, it's huge.

NARRATOR:
Reducing food waste
is one of many ways

engineers are trying
to slow climate change.

But the negative changes
we've made to our climate

are already damaging
some environments

like coral reefs.

MOONEY:
Coral reefs are in decline.

So one of the things
that I really think about

is how do we fix
the environment

that's sort of dying
in front of us?

NARRATOR:
Healthy coral reefs can be
stunningly beautiful

and play a critical role
in coastal ecosystems.

They harbor a tremendous
diversity of marine life

and contribute
to the overall health

of the world's oceans
and their coastlines.

A quarter of all marine species
depend on them for survival.

They're also important
to humans.

Often located in shallow water,

they can protect coastal
communities

from damaging storm surges.

And the reefs host a primary,
sustainable food source

for hundreds of millions of
people around the world.

But as the oceans warm,

corals are struggling
to survive.

Excessive heat drives away
the microscopic algae

the coral depend on.

That leads to
a dramatic loss of color,

known as coral bleaching--

a powerful visual indicator
of an unhealthy reef.

But bleaching isn't the only
indicator of a reef in peril...

MOONEY:
Not only it looks brown

and is lacking these beautiful,
vibrant colors,

but it just sounds dead.

(underwater ambient noise)

NARRATOR:
That's where sensory biologist
Aran Mooney comes in.

MOONEY:
My background is in hearing
and in bioacoustics.

And I study how animals
perceive the world around them.

(wildlife chittering)

Coral reefs are kind of
rainforest of the sea,

and just like
a really rich forest

might have
a lot of birds calling,

and you might hear the monkeys
calling in the background,

coral reefs are really the same.

So basically
a healthy coral reef

has a really
healthy rich soundscape.

(crackling, snapping)

NARRATOR:
Snapping shrimp, lobster,
and fish

create a symphony indicative
of a biodiverse community.

MOONEY:
And a degraded coral reef is
just an impoverished soundscape.

It sounds quiet,
kind of desolate.

So, by listening to
the soundscape,

we can kind of
track that biodiversity

and understand when
that change is happening.

♪ ♪

NARRATOR:
Off the coast of St. John
in the Caribbean,

a team from the Woods Hole
Oceanographic Institution

in Massachusetts

conducts bleaching surveys,

finding evidence of
degraded reefs.

(water splashing)

To your right,
there's some bleached coral.

You knew there's going to be
bleaching here, right?

But then it's freaking
everywhere, right?

YOGI GIRDHAR:
I've been coming here

five or six years now,

this was the first time

I have seen such bleaching.

NARRATOR:
Yogi Girdhar is a roboticist

and computer scientist
at Woods Hole.

GIRDHAR:
I am working on

robots and A.I.

and machine learning-based
techniques

to understand complex ecosystems
in the ocean,

such as coral reefs.

NARRATOR:
A question they pose:

is it possible to build a robot

that can seek out and
find healthy reefs

on its own?
(electronic beeping)

If they succeed,

the robot could provide an
efficient and cost-effective way

to find healthy coral reefs,
map them,

and monitor their health.

(electronic crackling)

The soundscapes recorded
by the robot

could be a vital tool
in diagnosing reef health

and tracking decline
or improvement.

♪ ♪

MOONEY:
Good job, team!

♪ ♪

NARRATOR:
The team has been collecting
data on reefs

for over a decade.

You're going through this.
Yeah.

I might be able to thread
it through here.

NARRATOR:
They have mountains
of information;

including audio and video.

They've even created 3D models
of the reefs

for further study.

Helping them gather this data

is this third-generation robot.

GIRDHAR:
We call it CUREE--

C-U-R-E-E.

It stands for Curious Underwater
Robot for Ecosystem Exploration.

NARRATOR:
It's equipped with sensors,
microphones, and cameras

and is still very much
under development.

GIRDHAR:
The design of a robot

is always evolving.

Our robot is never finished.

NARRATOR:
It's an engineering challenge

with a lot of moving parts.

So they've broken it down
into many small steps.

MARIA YANG:
There are many, many problems

that you can solve
with an engineering solution.

But I think you have to

really understand what
the problem is

and sort of pick the two
or three

that really you want
to address.

trying to solve all
the problems all at once

and you run out of resources.

♪ ♪

NARRATOR:
This morning, the team is
prepping for its latest test

right off the dock.

MOONEY:
All right, Dr. Girdhar.

Are you ready?

Always.

GIRDHAR:
I'll manage the tether.
Got it?

NARRATOR:
To start, they'll place a
speaker on the ocean floor,

playing a recording
of a healthy coral reef.

A sound file they captured

from a previous trip.

SETH McCAMMON:
It should be on.

GIRDHAR: Yeah.
All right.

We hear it.

(electronic crackling)

NARRATOR:
They're hoping the robot

will recognize the sound
through the water

and be able to record it.

In this outing,

the robot is
not moving autonomously.

Researcher Seth McCammon

is operating the robot remotely

to steer and position it
for the test.

I'm getting it in line
with the thing

so we can start to look
at the data.

GIRDHAR:
If the robot doesn't work
with this sound,

it's probably not going to work
on the real coral reef,

so it's a good, good test.

NARRATOR:
Experimenting with sound
underwater

is not a new idea.

In the 1800s,

a Swiss physicist
and a French mathematician,

armed with a bell and stopwatch,

measured the speed at which
sound traveled underwater.

On one side of Lake Geneva,

Charles François Sturm
rang a submerged bell,

(bell ringing)
while Jean-Daniel Colladon

used a long tube to listen
underwater across the lake...

(watch clicks)
...pressing his stopwatch

to keep track of how long
it took

the sound to travel across.

Surprisingly,
they found that water

is a better conduit for sound
than air.

Sound travels through water

roughly five times faster.

Today, the Woods Hole team

will be using
the speed of sound underwater

as part of their calculations.

The robot is equipped

with four microphones
designed for underwater use

called hydrophones.

As the sound from the speaker
speeds through the water

in all directions,

it reaches the hydrophones at
slightly different times--

just milliseconds apart.

The researchers look at
a computer display

that shows
the signals recorded...

(electronic chirping)
...on each hydrophone.

McCAMMON:
And so it will hit one
hydrophone before the others

and by looking at
the relative time of arrival

at those different hydrophones,

we can figure out which
direction it came from first

and then steer the robot
in that direction.

♪ ♪

NARRATOR:
The robot correctly identifies

the direction of the sound--

an important first step
toward autonomous navigation.

♪ ♪

A small but important victory.

♪ ♪

McCAMMON:
It's like you're building
out of LEGOS

and you're building up a house,

brick by brick by brick.

And it only works

when the house is
fully done.

But you need to know

that each single brick
in that

works on its own
in isolation

MABRY:
And so, you have this
massive goal

that you're trying to achieve,

but there needs to be attainable
goals along the way

because ultimately,

you're dealing with a system
of components,

a system of elements

that need to work together

in order for this

to be successful.

NARRATOR:
CUREE is ready to step up

to a bigger challenge.

Locating an actual healthy reef
by sound--

something less predictable than
what the speaker provided.

One of the healthier reefs
in St. John

is in nearby Joel's Shoal.

GIRDHAR:
I propose we drop the robot

like 20 meters...

MOONEY:
We're like ten meters

off the reef right now.

NARRATOR:
They'll place CUREE

approximately 20 meters
from the reef.

(electronic chirping)
To succeed,

it just needs to orient itself

toward the sound.

Robot going in.

All right, cast away!
(electronic melody)

McCAMMON:
So the test today

is mostly just trying
to figure out

if the robot can
accurately determine

which direction
the reef sound is in.

NARRATOR:
It's a more complex test.

This time CUREE is untethered

and the boat is drifting
with the ocean current.

NARRATOR:
If they lose contact,

they could easily lose
the robot entirely,

and all of the engineering
that went into it.

♪ ♪

MABRY:
When they began to design
this autonomous robot

that would go underwater,

there is a need
to make sure that

this thing is able to behave

in an environment where,
if it doesn't,

we can retrieve it...

NARRATOR:
CUREE locates the direction
of the healthy reef.

Which is encouraging.

NARRATOR:
It's another successful test.

(electronic crackling)

The next big hurdle,

can CUREE not only locate,

but then move towards
a healthy reef autonomously.

This will be a crucial milestone
in the mission,

which is to ultimately build
a fleet of robots

to map, monitor, and record

the health of corals
around the globe.

While reefs are under serious
threat all over,

there are some signs of hope,

and some surprising ideas
for ways to protect them;

including one that came from
this team's research.

♪ ♪

In their work, they discovered
that the sound of a healthy reef

might actually have
an indirect healing effect

on a stressed reef.

It has to do with
the coral animal's life cycle.

Newly born baby corals--

tiny larvae--
drift in the ocean,

searching for somewhere
to settle.

It turns out the sound of
a thriving coral reef

signals them
to settle into place.

Once they find a spot,

they can be very resilient

and grow for centuries.

So the more larvae a reef
can attract,

the healthier it will be.

And that gave the team an idea.

We know these reefs
are degraded

and we want
to rebuild them

by attracting the larvae, the
baby coral.

the team found that larvae

could be drawn to recordings
of healthy reefs.

So by placing speakers in
strategic locations,

they could give a boost
where it's needed most.

MOONEY:
And that system actually

leverages the healthy landscape

and plays it back into
the environment

and the idea is that
it induces coral larvae

to kind of choose that
environment and settle.

NARRATOR:
The result?

Up to seven times more
larvae settlement

compared to a degraded reef

without the audio boost.

A very encouraging sign.

♪ ♪

But back to St. John and CUREE.

The team is ready for
the final test of the day.

McCAMMON:
The robot is going
to use the direction

that it's finding
from its hydrophones

and then drive itself

to whatever the nearest
acoustic source is,

which we're hoping is going
to be Joel's Shoal Reef.

NARRATOR:
This time,
since CUREE will pilot itself,

it's tethered for safety.

They put CUREE in the water
and give it the green light.

NATE FORMEL:
Are we expecting it

to be moving or not?
McCAMMON: We are.

NARRATOR:
It looks at first
as though it's orienting

toward the sound of the reef.

It thinks it's moving.

NARRATOR:
But after a few minutes
it's clear

that CUREE isn't making
much headway.

It's just dumb stuff
in the way that I wrote.

NARRATOR:
It seems there's an issue
with the software.

♪ ♪

All right, bring it back.

(ratcheting)

It's coming up.

FORMEL:
I can now see it.

NARRATOR:
They're starting to
lose the light.

It's getting dark.
(indistinct chatter)

NARRATOR:
They weren't able
to check off everything

on the day's to-do list,

yet they remain upbeat.

GIRDHAR:
Overall, I am happy
right now because...

McCAMMON:
We ended the day
with as many robots

as we started
the day with.

NARRATOR:
It's frustrating in
the moment,

but they're making progress.

STELTZNER:
The creative act of engineering

has got disappointment,

has got failure,

and that's how we learn.

(chuckling):
So, it is a big ball of, of...

...two steps forward and
one step back.

When you have
a very massive "Why"

and a very massive purpose for
what you're trying to do,

such as save the coral reefs,

it allows you to experience
the disappointment

but not be defeated by it,

and continue to try the process
of moving it forward.

♪ ♪

If you're not failing
you're not trying hard enough.

(voiceover):
Yeah, it's very frustrating

but when it works,

it's very satisfying.

will require creativity,
innovation,

and a global commitment
to making smart choices.

But we face many other
challenges as well;

like restoring balance
to the land

after decades of
industrial pollution.

♪ ♪

On Navajo land in Arizona,

an Indigenous artist and
engineers are collaborating

on a unique, local approach

to purifying
contaminated drinking water.

(birds chirping)
This pristine-seeming landscape

conceals a serious problem.

30% of the population in
the Navajo Nation

lacks access to
clean drinking water.

Decades of uranium mining

has polluted the land.

The United States government

used the heavy metal

to develop the atomic bomb

and power its
nuclear weapons program

after World War II.

CHACHRA:
When we think of engineering,

people are suspicious
of it because,

for a good part of
the 20th century,

was engineers making
decisions about systems

that affected
a lot of other people.

And often those effects
were not positive.

NARRATOR:
Byproducts of uranium mining,

such as strontium,

can mimic calcium in the body,

causing it to be absorbed
by bones.

The E.P.A. has awarded
$3.8 million

to support
three drinking water projects

to benefit the Navajo Nation.

Some are proposing other, more
homegrown solutions, as well.

(stone grinding)

Deanna Tso is a third-generation

Navajo artist who works in clay.

TSO:
People always ask me,

"When'd you learn how
to do pottery?"

I always say,

"I was born making it."

Both my parents,
my mother and my father,

both did Navajo pottery.

(car doors closing)

NARRATOR:
She has been collaborating
with scientists

Navid Saleh
and Stetson Rowles...

(knocks on door)

Hey!
Good morning.

Hey, Deanna.

NARRATOR:
...on a project meant to address

the water contamination problem

on a very human scale.

SALEH (voiceover):
I believe that engineering
without people

is destined to fail.

SALEH (voiceover):
There is this
experiential knowledge,

knowledge that is housed
within people's lives,

yet to be unlocked.

NARRATOR:
Not all people here use

or have access
to municipal water,

so the goal is
to call upon local knowledge

to find a sustainable way
to purify water

closer to the home.

YANG:
We often think

of engineering as
only being

the latest and greatest
technology.

and, and have been for,

you know,
decades, centuries longer.

And so what can we learn from
those, existing approaches

that are already effective?

So Deanna,
this was something that...

NARRATOR:
On this trip,
the scientists want to build

a new prototype clay filter

for use in household
water containers.

The hope is to integrate
locally sourced minerals

so that the finished filter
will remove uranium byproducts,

like strontium, from the water.

SALEH:
Could you actually make
something like that?

Do you have something similar?

I have one that I make

with the cone shape.

NARRATOR:
Navajo potters like Deanna

use a local tree sap
as a glaze.

Navid and his team wondered
if the sap could be used

as part of a
decontamination filter.

SALEH (voiceover):
What we found was how
much knowledge

the Navajos already had
about the sap.

They already knew it has
health benefits.

So this is a printout
of the...

NARRATOR:
Navid and his team
recently conducted tests

that translated
Indigenous knowledge

into the language of
biochemistry;

quantifying the extent of the
sap's antimicrobial properties.

Now, they hope to expand
the filter's capabilities

to radioactive contaminants.

YANG:
They worked together,
collaboratively,

to make something new and better

that serves her community
in a really, powerful

and very collaborative way.

We can engineer
a shape or a design

that's going to work well,
not only to filter water,

but people will want to use.

(voiceover):
We see this amazing opportunity

to be able to use pottery,

or ceramics, as filters,

because it's so a part

of people's everyday life.

Particularly in places like
the Navajo Nation

where traditional practices
are so important.

TSO:
Okay.

ROWLES:
Which way?

NARRATOR:
Navid and Stetson want to learn
the process of making pottery

the way Deanna's mother
taught her--

because collaboration
is strongest

when it is
truly interdisciplinary.

TSO:
Yes.

You see that
gray spot?

NARRATOR:
Deanna starts from scratch,

harvesting clay from
a rocky outcropping

on Navajo land.

Okay,
so this portion is what?

That portion is clay.
Okay.

SALEH (voiceover):
We often as scientists believe

that we know a lot.

But we forget,

science as a discipline

has only been around
for 500 years.

NARRATOR:
There are many ways of
generating knowledge

besides
the modern scientific process.

CHACHA:
These are all different ways

in which we interact
with the physical world.

That diversity gives
you new ideas.

And thinking about how
to put together

old technologies and
new technologies

might lead to entirely
new paths.

It creates a symbiotic
effect,

because the more people
feel included

in what is being produced
by something,

the producing of that thing.

NARRATOR:
Next-- they source sap
from pinyon trees.

There's one right here,
let's check this one.

♪ ♪

(crunches)
ROWLES: Whoo!

We hit the jackpot
with this tree.

TSO:
We were blessed for the day.

Come on in.
(keys jangling)

I usually just take
this much out.

NARRATOR:
Deanna demonstrates how
to grind minerals

into the fine grains
that make up her clay.

One of you want to go ahead
and give it a try?

ROWLES:
I think there's a lot
of engineering

that goes into creating pottery.

The freedom that it allows
to make any shape.

(squeaking)

STELTZNER:
The fusion of art and
engineering.

Or maybe even the boundaries
between art and engineering...

...perhaps they don't exist.

Perhaps they're really
the same thing,

painted with a different
palette.

NARRATOR:
Stetson and Navid
are working with Deanna

to prototype a shape for
the clay filter.

I don't know if you know
Deanna,

but I've been making
some pottery since high school,

and I made this shape
to try and see

if maybe we can explore
making some shapes together.

I made a shape
similar to that...

...and it looks like this.

And we do make these
traditional Navajo pipes.

Do you think you can
make some grooves

similar to something
like this?

Kind of like an accordion
basically,

so it has the same surface area
but in a smaller size.

♪ ♪

NARRATOR:
Adding grooves increases the
total surface area of the shape.

More surface area
will mean more contact

with the water inside.

TSO:
I'm going to show you

an option we have
that we can try:

Coil.
Yeah. Making a coil.

Making a coil.

♪ ♪

NARRATOR:
Next, the new prototypes

need to be fired.

SALEH:
We have been working
with Deanna

for almost nine years now.

TSO:
Make sure we have it covered
nice and good.

SALEH:
Working with her side-by-side

as an equal partner
intellectually,

only opens opportunities that
are more meaningful

than we scientists would
ever find

sitting at our desks.

NARRATOR:
The last step:

heat and strain the pinyon sap,

creating
the microbe-resistant resin,

which acts as a glaze
to coat the pottery.

And now, a new addition
to the filter.

ROWLES:
Can you grab the zeolite?

NARRATOR:
The scientists are using
powdered chabazite,

a type of
naturally occurring zeolite,

found abundantly on Navajo land.

♪ ♪

Chabazite is a porous crystal

made of sodium, calcium,
and aluminum silicates

that has the ability to trap

and absorb contaminants.

♪ ♪

Finally, Deanna applies
the resin.

TSO:
The pottery itself
has to be hot.

The sap has to be hot.

NARRATOR:
The team hopes the chabazite

will add function to the resin,

removing uranium byproducts,
like strontium,

from any water that comes
into contact with it.

ROWLES:
Wow, the colors are beautiful.

♪ ♪

NARRATOR:
Back at the University of Texas
at Austin,

it's time to test their water
filter prototypes in the lab.

We've got some of
the clay.

NARRATOR:
Using the materials

they sourced with Deanna,

the scientists create
small clay discs...

ROWLES:
...try and just punch out,

a little disc like that...

NARRATOR:
And coat them with the same
chabazite-enriched resin.

These are tiny lab versions
of Deanna's pottery.

To test the discs,

the researchers expose them

to strontium-contaminated water

to see if the resin
will successfully absorb

the uranium byproduct.

♪ ♪

If the filter works as expected,

the chabazite will capture
strontium from the water

through ion exchange
as the water passes through.

♪ ♪

ROWLES: Hey, Andrei.
ANDREI DOLOCAN: What's up, bud?

Here's the sample.

Yeah, thank you.

NARRATOR:
Senior research scientist

Andrei Dolocan

loads a sample into
an ion mass spectrometer.

It scans the sample

on the molecular level,

layer by layer,
over several hours.

When it's done,

the result
is a map of the elements

within the scanned
sample surface.

When the clay disc
is completely scanned,

it's time
to check the results.

This is the
strontium signal.

NARRATOR:
The data show that
the strontium is found

in the same places as chabazite
in the resin...

DOLOCAN:
We have the zeolite,
obviously sodium,

aluminum-silicon.

Uh-huh.
DOLOCAN: Okay.

And now the, strontium is
increasing exactly like...

NARRATOR:
It's an encouraging sign

that the chabazite is working
as expected

when used with
Deanna's pottery technique.

SALEH:
So I guess it was a really,

successful run, Andrei.

Yeah.
We can see association

of strontium
with the zeolite.

DOLOCAN:
I agree, this is a good start.

ZILEVU:
One thing that I've learned

from the research and
design process

is that kind of doing

co-creation activities
with the end user,

it's really a way to kind
of bridge and create

new, innovative process,

because you're bringing
the people

who are using the technology

throughout the whole journey.

So this is the one
that Deanna made...

NARRATOR:
Now a few steps closer
to their goal,

the researchers will work

to incorporate Deanna's spiral

and the chabazite's
filtering power

into their final design.

So moving forward,

I think the most difficult
engineering challenge

is yet to come.

And I think it's going to be

translating our results from,

you know, a lab scale experiment

to something that's going
to be usable

in households throughout
the Navajo Nation.

♪ ♪

(birds chirping)

MABRY:
At the end of the day,

we want
to unlock human potential.

And in order
to unlock human potential,

we are not doing
ourselves a justice

if we continue to only demand
certain solutions

from a subset of
our populations,

the more we can get
more people included,

the more we can unlock

not just solutions to problems
that we now see,

but things that are yet to come.

♪ ♪

NARRATOR:
As we change our world through
engineering,

it's up to us to make changes;

for all of us, by all of us.

ARMANI:
I think we're all engineers.

We all build things,

we all design things.

(chuckling):
We all break things

and then have to fix them

and put them back together.

NARRATOR:
And we get to decide

what comes next.

What if we were to design this?

What if the world was
to look like this

in 50, 100 years?
What could that look like?

♪ ♪

ALI HAJIMIRI:
The engineer's work
is never done...

If you're not failing,
you're not trying hard enough.

You can always create
something new.

♪ ♪

NARRATOR:
Building stuff

to change the world.

♪ ♪

♪ ♪

♪ ♪

♪ ♪

♪ ♪

♪ ♪

♪ ♪