All language subtitles for 1255823DD9954F9E94F1E4C923EDCE19_eng

The age and size of the cosmos are written
in light.

The nature of beauty and the substance of
the stars, the laws of space and time,

they were there all along.

But we never saw them, until we devised a
more powerful way of seeing.

The story of this awakening has many
beginnings and no ending.

Its heroes come from many times and
places.

An ancient Chinese philosopher,
a wizard who amazed the caliphs of 11th

century Iraq, a poor German orphan
enslaved to a harsh master.

Each one brought us a little closer to
unlocking the secrets hidden in light.

Most of their names are forever lost to
us.

But somewhere long
ago, someone glanced up

to see light perform
one of its magic tricks.

Who knows, maybe that quirk of light
inspired the very first artists.

Where did all this come from?

How did we evolve from small wandering
bands of hunters and gatherers living

beneath the stars to become the builders
of a global civilization?

How did we get from there to here?

There's no one answer.

Climate change, the domestication of fire,
invention of tools, language, agriculture,

all played a role.

Maybe there was something else too.

In China, more than 2,000 million people
lived there.

A hundred years ago, a philosopher named
Mot Su is said to have observed that light

could be made to paint a picture inside a
locked treasure room.

This was the description of the first
camera.

The camera obscura.

The prototype of all
image-forming cameras,

including the one that's
bringing you this picture.

Taking advantage of this
funny thing that light does

resulted in what could
be called the first movie.

Mot Su, master of light, worked against
all forms of darkness.

A military genius who only used his
talents to prevent violence.

He was legendary for traveling among the
kingdoms of the warring states,

employing ingenious strategies to talk
kings out of going to war.

He was one of the first to dream of
universal love and an end to poverty and

other forms of inequality, of government
for the people.

And to argue against blind obedience to
ritual and authority.

In his writings, you can find early
stirrings of the scientific approach.

By Mot Su's time, the Chinese
had already been recording

their thoughts in books for
at least a thousand years.

Still, our knowledge of him is only
fragmentary.

It consists largely of a collection of
essays attributed to him and his disciples.

In one of them,
entitled Against Fate, a

three-pronged test for
every doctrine is proposed.

Question its basis.

Ask if it can be verified by the sights
and senses of common people.

Ask how it is to be applied and if it will
benefit the greatest number.

Mot Su was extremely popular, but a few
hundred years after his death,

Qin Shi Huang, the first emperor and
unifier of China, took power.

He took a continent and turned it into a
nation that now bears his name.

China.

Most of us know Emperor
Qin for the army of

7,000 terracotta warriors
that guard his tomb.

In Emperor Qin's drive to
consolidate his far-flung empire,

he took drastic measures to
standardize everything within it.

This included mandating a single coinage,
making uniform all weights and measures,

the widths of carts and roads,
as well as the precise way the Chinese

language was to be written, including what
you are allowed to write and think.

Emperor Qin's philosophy,
the only one permitted, was

called legalism, which was
just what it sounded like.

Do as the law says, or else.

It's a philosophy that's not highly
conducive to questioning authority.

The king has an order.

That all the books of the hundred schools
of thought shall be burned.

That anyone who uses history to criticize
the present shall have his family executed.

The works of Motsu and
Confucius and other philosophers

were destroyed in the
world's first book burning.

Hundreds of scholars bravely resisted by
trying to preserve the forbidden books.

They were buried alive at the capital.

Science needs the light of freedom.

It needs free expression to flourish.

It depends on the fearless questioning of
authority, the open exchange of ideas.

Sparks of curiosity in
the writings of Motsu

and his disciples were
effectively stomped out.

It would be another thousand years before
the next movie.

Luckily, our ship of the imagination can
take us anywhere in space and time.

Ancient Chinese and Greeks observed that
light could be made to do wonderful things.

But no one asked that question favored by
small children and geniuses alike.

Why?

Until a thousand years ago.

In the city of Basra, Iraq, there lived
another master of light.

Ibn al-Hazen had a passionate desire to
understand nature.

He questioned everything.

Especially those things that everyone else
took for granted.

How do we see?

He asked.

Some of the great authorities who came
before him had taught that rays come out

of our eyes and travel to the objects we
see before returning to our eyes.

But al-Hazen reasoned that the stars were
too far distant for something in our eyes

to travel all the way to them and back in
the blink of an eye.

Excellent reasoning.

But al-Hazen didn't stop there.

He searched for ways to compel nature to
divulge her secrets.

His culture was open to new ideas and
questioning.

It was the golden age of science in the
Islamic world.

One that stretched from Cordoba in Spain
all the way to Samarkand in Central Asia.

Christian and Jewish scholars
were honored guests at the

research institutes of Baghdad,
Cairo and other Islamic capitals.

Instead of burning
books, the Caliphs sent

emissaries around the
world in search of books.

The Caliphs lavishly
funded projects to translate,

study and preserve them
for future generations.

Much of the light of ancient
Greek science would have

been permanently
extinguished without their efforts.

The reawakening to science that took place
in Europe hundreds of years later was

kindled by a flame that had been long
tended by Islamic scholars and scientists.

The Arabs also imported ideas from India
to the West.

Including the so-called Arabic numerals
that we all use today.

And the concept of zero.

Which comes in handy when you want to
write billions and billions.

Arabic astronomy was
so influential that we still

call most of the bright
stars by their Arabic names.

And the Al's in algebra, algorithm,
alchemy and alchemy.

And alcohol are just
some of the traces left from

the time when Arabic was
the language of science.

In the 11th century, Ibn
al-Hazen set about trying

to test his ideas about
light and how we see.

So he devised an experiment to determine
how light moves.

He erected a tent in full daylight and
sealed it tightly so that only a single

ray of light could pierce its inner
darkness.

With little more than his brains and a
straight piece of wood, a ruler.

Al-Hazen had accomplished a great leap
forward in the history of science.

He discovered that light moves in straight
lines.

But he was just getting started.

Al-Hazen figured out that the key to
forming any image, whether you're talking

about an eye or camera obscura,
is a small opening to restrict the light

that can enter an otherwise darkened
chamber.

That aperture excludes the chaos of
extraneous light rays that surround us.

The smaller the aperture, the fewer
directions that light can come from.

And that makes the image sharper.

So instead of being blinded by the light,
we can see everything it has to show us.

Al-Hazen made his own camera obscura and
dazzled the caliphs.

A camera obscura works best in bright
light.

The stars of the night sky are way too dim
for this.

We somehow need a bigger opening to
collect light.

But we also need to maintain focus.

A telescope collects light from any spot
in its field of view.

Across the entire lens or mirror.

An opening much larger than the camera
obscura hole.

This is one of the first telescopes.

The one that Galileo looked through in
1609.

With it, he pulled aside the heavy curtain
of night.

And began to discover the cosmos.

Al-Hazen made it possible
for a telescope to have a

much larger light collecting
area than our eyes have.

Big buckets catch more rain than small
ones.

Modern telescopes have larger collecting
areas, highly sensitive detectors.

And they track the same object for hours
at a time.

To accumulate as much of its light as
possible.

Space-based telescopes such
as the Hubble have captured

light from the most distant
and ancient galaxies.

Giving us vastly clearer pictures of the
cosmos.

Al-Hazen discovered how images are formed
by light.

But that was far from his greatest
achievement.

Ibn Al-Hazen was the first person ever to
set down the rules of science.

He created an error-correcting mechanism.

A systematic and relentless way to sift
out misconceptions in our thinking.

Finding truth is difficult.

And the road to it is rough.

As seekers of the truth, you will be wise
to withhold judgment and not simply put

your trust in the writings of the
ancients.

You must question and critically examine
those writings from every side.

You must submit only to
argument and experiment

and not to the
sayings of any person.

For every human being is vulnerable to all
kinds of imperfection.

As seekers of the truth, we must also
suspect and question our own ideas.

As we perform our investigations.

To avoid falling into prejudice or
careless thinking.

Take this course and truth will be
revealed to you.

This is the method of science.

So powerful that it
has carried our robotic

emissaries to the edge of
the solar system and beyond.

It has doubled our lifespan.

Made the lost world to the past come
alive.

It has brought us to the present.

Science has enabled us to predict events
in the distant future.

And to communicate with each other at the
speed of light.

As I am with you right at this moment.

This way of thinking
has given us powers that

Alhazen himself would
have regarded as wizardry.

But it was he who put us on this rough,
endless road.

And now it has taken
us to a place where

even light itself is
enshrouded in darkness.

Light has properties unlike anything else
in the realm of human existence.

Take the speed of light.

The basic particle of light, a photon,
is born traveling at the speed of light.

As it emerges from an atom or a molecule.

A photon never knows any other speed.

And we have not found
another phenomenon that

accelerates from zero to
top speed instantaneously.

Nothing else can move as fast.

But we try to accelerate other particles
closer and closer to the speed of light.

They resist more and more as though they
are getting heavier and heavier.

No experiment yet devised has ever made a
particle move as fast as light.

What was that?

Did you hear something?

Was I?

Oh yeah.

I don't know anything else in life that
behaves like light.

I cannot reconcile its strange properties
with everything else my senses tell me.

Our urge to trust our senses
overpowers what our measuring

devices tell us about
the actual nature of reality.

Our senses work fine for life-size objects
moving at mammal speeds.

But they're ill adapted for the wonderland
laws of light speed.

We don't even know why there's a cosmic
speed limit.

Time stands still.

You know when you're traveling at the
speed of light.

But he is light anyway.

Isaac Newton's enduring fascination with
light began when he was a child.

In this very house.

By the time he was in his
twenties, Newton became the

first person to decipher
the mystery of the rainbow.

Newton discovered that
sunlight, or white light,

is a mixture of all the
colors of the rainbow.

Major discovery.

He named the displays of colors a
spectrum.

From the Latin for phantom, or apparition.

Begging

your pardon, Master Newton.

But Cook Fred said that your dinner will
spoil, sir.

No, Isaac.

Don't put the magnifying glass down.

Something even more amazing is hidden in
the light.

A code.

A key to the cosmos.

Isaac Newton didn't miss much.

But that one was a beaut.

He just walked right past the door to a
hidden universe.

A door that would not swing open again for
another hundred and fifty years.

It would fall on another scientist,
working in the year 1800, to stumble on a

piece of evidence for the unseen worlds
that surround us.

By night, William Herschel
scanned the heavens

with the largest
telescope of his time.

By day, Herschel performed experiments.

From Newton's earlier
work, it was known

that sunlight is a
blend of different colors.

And everyone knew, just from being
outside, that sunlight carries heat.

William Herschel asked whether some colors
of light carry more heat than others.

The nature of
scientific genius is to

question what the rest
of us take for granted.

And then do the experiment.

The thermometer that Herschel placed
outside the spacecraft was his control.

The control in any experiment always lacks
the factor being tested.

That way you know if
what you're testing is

really the thing responsible
for the observation.

In Herschel's experiment,
the relationship

between color and
temperature was being tested.

And so his control was a
thermometer over the part of the

white sheet that was not
illuminated by sunlight at all.

Here's that sound again.

What is that?

Okay, red light is warmer than blue light.

Interesting discovery, but not exactly
revolutionary.

No, there's nothing wrong with your
thermometer.

You've just discovered a new kind of
light.

Herschel was the first to
detect this unseen presence

lurking just below the
red end of the spectrum.

That's why it came to be called infrared.

Infra is Latin for the word below.

It's invisible.

Our eyes are not sensitive to this kind of
light, but our skin is.

We feel it as heat.

Now that's a really big discovery.

But far greater secrets were still hiding
deep inside the light.

At about the same time that William
Herschel was discovering infrared light in

his parlor in England, a
young boy named Joseph

Fraunhofer was trapped
in hopeless drudgery.

He stood over a cauldron of toxic
chemicals and endlessly stirred.

Joseph had been orphaned
at the age of 11 and given to a

harsh master named
Weichelberger, the royal mirror-maker.

He prevented Joseph from going to school.

Instead, Joseph labored in
the glass-making workshop by

day and tended to the master's
household chores by night.

Hurry up!

That's stupid.

And remember, no reading.

Until Joseph got his big break.

Weichelberger's house collapsed.

Maximilian, the future
king of Bavaria, hurried to

the scene of the calamity
to see if he could help.

Maximilian was known
for taking an interest in his

subjects, which was
highly unusual for its time.

In attracting the concern of the future
king of Bavaria, young Joseph Fraunhofer

found an aperture into a different
universe.

And not just for himself.

Prince Maximilian gave Joseph money and
asked his privy counselor to provide

further help to the boy should it be
needed.

Weichelberger continued to exploit him and
prevent him from attending school.

But the prince's counselor
intervened, offering

Joseph a position
at the optical institute.

This small gesture of kindness really paid
off.

By the time he was 27, Joseph Fraunhofer
was the world's leading designer of

high-quality lenses, telescopes,
and other optical instruments.

His firm was housed here in the old
Benedikt-Guyen Abbey.

In the early 19th century, this was
top-secret, ultra-high technology.

The Benedikt-Guyen monks of earlier times
had taken a vow of secrecy.

This local tradition and the ability to
restrict access to Fraunhofer's laboratory

allowed him to maintain control of trade
and state secrets.

Fraunhofer was
experimenting with prisms to find

the best types of glass
for precision lenses.

How, he wondered, could he get a better
look at the spectrum that a prism produced?

Friedrich, bring me the theodolite,
please.

Okay, while Fraunhofer sets up his
theodolite as a kind of telescope,

I want to show you something in another
part of the Abbey.

Sound waves are so beautiful to hear.

Imagine how beautiful they'd be to see.

Organ pipes have different lengths.

I press a key.

It sends compressed air into a particular
pipe, producing sound waves.

If we could slow the sound waves down a few
hundred times, they would look like this.

The length of the pipe
determines the length

of the sound wave
that can fit inside it.

A short pipe gives you a short sound wave.

Short sound waves have high pitch or
frequency.

Let's stop the waves for a better look.

The distance between adjacent waves is
called the wavelength.

A long pipe gives you a long sound wave,
with a low pitch or low frequency.

Hmm.

The medieval manuscript
of this music, Carmina

Burana, was discovered
in this very abbey.

Sound waves can't travel through a vacuum.

They need matter to ride on, like
molecules of air or water or rock.

But light waves fly solo.

They can move through
empty space and fast, a

million times faster than
sound waves and air.

And the wavelengths of the light we see
are so much shorter than sound waves,

about 50,000 light waves would fit right
in here.

Oh yeah, Fraunhofer.

Just in time.

We didn't miss it.

Just as the wavelength of
sound determines the pitch that we

hear, the wavelength of light
determines the color that we see.

But how does a prism spread out the colors
concealed in a beam of sunlight?

When light travels through air or space,
all its colors move at the same speed.

But when it hits glass at an angle, the
light slows down and changes direction.

Inside the prism, each color moves at a
different speed.

In glass, violet light, which is carried
by the shortest waves we see, slows down

more than red light, which has the longest
waves.

These changes in speed
pry the colors apart, sending

their waves off in
slightly different directions.

That's how a prism works.

If I seem unduly emotional about this,
it's because Joseph Fraunhofer is about to

do what Isaac Newton could have done but
didn't.

And it will have a powerful effect on the
course of my own life.

You are witnessing the marriage of physics
and astronomy.

The birth of my own field of science.

Astrophysics.

Written in the light.

Those vertical black lines?

The secret code.

Fraunhofer looked at them and wondered
why.

A code that comes to us from an alien
universe.

What is the message written in these dark
vertical lines?

What are you?

Who are you?

It took a hundred years of thinking.

Lovely, isn't it?

Why?

There are many layers to the fine
structure of beauty.

The chemistry of the earth and its
atmosphere.

The evolution of life.

Many distinct threads.

Let's just examine one at the surface.

The colors of nature that dazzle us.

What's really happening?

How does the red, the blue, the
astonishing palette of nature's colors,

how do they happen?

Light waves of different lengths from the
sun strike the earth.

The petals of these
particular flowers absorb all

the low energy, long
red wavelengths of light.

But the petals reflect the shorter high
energy blue wavelengths.

That interaction between
starlight and petal,

or water, or Van Gogh,
is what makes blue.

The longest waves, the ones we see as red,
have the lowest energy.

Color is the way our eyes perceive how
energetic light waves are.

A sunset.

A flag.

The eyes of your beloved.

That shiny new car.

The feelings they inspire happen when
something inside you is triggered by a

particular variation in the frequency and
energy of light waves.

And the secret message, those black
vertical lines in Fraunhofer's spectrum?

What makes them?

They occur when the light waves of those
particular colors are being absorbed.

It happens on another
level of reality, far

smaller than the world
we're used to operating in.

To get there, we'll need to become ten
billion times smaller than we are.

We could pick any one of these atoms.

But let's go for the hydrogen atom.

The hydrogen atom is the most plentiful
kind of atom in the cosmos.

And the simplest.

It has only one electron.

And only one proton.

We've entered the Quantum Round.

It doesn't correspond to ordination.

This is an extraordinary human experience.

Common sense is no help here at all.

Take the hydrogen atom's electron,
for example.

In an atom, an electron doesn't exist
between orbitals.

It disappears from one orbital and
reappears in another.

It's as if you took an elevator from the
second floor to the fourth floor,

but ceased to exist in between.

And another thing.

Quantum elevators only stop at certain
floors.

The sizes of the
electron orbits are strictly

limited and different for
the atoms of every element.

That's why the elements are different.

The chemistry of anything is determined by
its electron orbits.

The force that holds an electron in orbit
has nothing to do with gravity.

It's a force of electrical attraction.

The electron dances a wavy
ring around the central nucleus of

a hydrogen atom and makes
quantum leaps from orbit to orbit.

Up or down.

The larger the orbit, the greater the
energy of an electron.

An electron has to get
energy to leap to a larger

orbit, and it has to lose
energy to jump back down.

Every upward leap is caused by...

an atom absorbing a light wave.

But we have no idea what causes the
downward leaps.

What we do know is that such leaps always
produce a light wave whose color matches

the energy difference between the
orbitals.

The Sun's surface radiates light waves of
all colors.

If you look at sunlight through a prism,
you'll see its spectrum.

When you magnify the spectrum with a
telescope, as Joseph Fraunhofer did,

you raise the curtain on the electron
dance within the atom.

When the energy of the
electron flags and it drops

to a lower orbital, the
light wave it emits scatters.

Most of it doesn't reach us.

It leaves a dark gap or black vertical
line in the spectrum.

These dark lines are
the shadows cast by

hydrogen atoms in the
atmosphere of the Sun.

Sodium atoms cast different shadows.

Their electrons dance to a different tune.

A grain of table salt is composed of
sodium and chlorine atoms, 10 million

billion of them, doing their crazy dances
in a single grain of salt.

And a single iron atom with 26
electrons...

is like a great big production number in a
Broadway musical.

When you look at a star
with a spectroscope, you see

the dark lines from all the
elements in its atmosphere.

Show me the spectrum of
anything, whether here on Earth or

from a distant star, and
I'll tell you what it's made of.

Fraunhofer's lines are
the atomic signatures

of the elements writ
large across the cosmos.

As with every other major
revelation in the history of

science, it opened the way to
newer and deeper mysteries.

And to the revelation that there were many
more sequels hiding in the light.

When Joseph Fraunhofer combined a prism
with a telescope and turned it towards the

skies, he brought the stars much closer to
us.

When he was only 39, he contracted a fatal
illness, perhaps as a result of his early

and long-term exposure to the toxic
chemicals of glassmaking.

You never know where the next genius will
come from.

How many of them do we leave in the
rubble?

The prince and his
kingdom were immeasurably

enriched by the act of
kindness to a poor orphan.

Fraunhofer's discoveries
transformed Bavaria from

a rural backwater to a
technological powerhouse.

As he lay dying, the government was
desperate to preserve every shred of his

precious knowledge about the high
technology of optical glass.

But it could only be
divulged to a person with

top security clearance,
the director of the Mint.

The government kept Fraunhofer's
technology from making perfect optical

glass a state secret for another hundred
years.

This would prove to be a major obstacle for
someone we'll meet later in our journey.

But Fraunhofer would
allow no such secrecy where

his pure scientific
research was concerned.

He knew that science
requires openness to flourish,

that our understanding of
nature belongs to the world.

As soon as Fraunhofer
discovered the spectral

lines, he published
everything he knew about them.

And the reverberations of his momentous
discovery echo still.

His spectral lines
revealed that the visible

cosmos is all made
of the same elements.

The planets.

The stars.

The galaxies.

We, ourselves, are all of life.

The same star stuff.

He made it possible for us to know what's
in the atmospheres of other worlds.

And in galaxies millions of light-years
away.

Spectral lines revealed not only the
composition of far-off objects,

but also their motion towards or away from
us.

Using them, we discovered that our
universe is expanding.

But perhaps the greatest
revelation of spectroscopy

is the discovery of
the thing it cannot see.

A hidden universe of dark matter.

Six times more massive than the familiar
cosmos.

It's made of some
mysterious substance that does

not emit, reflect, or
absorb any kind of light.

We only know it's there because of its
gravity, which pulls on all the galaxies

and speeds up the visible stars within
them.

There are many more kinds of light than
our eyes can see.

Confining our perception
of nature to visible light

is like listening to
music in only one octave.

There are so many more.

They differ only in wavelength,
but over a huge range.

For instance, infrared light.

The kind that William Herschel discovered.

Or X-ray light.

Or radio light.

Or in gamma ray light.

These are not just different ways of
seeing the same thing.

These other kinds of light reveal different
objects and phenomena in the cosmos.

In gamma ray light, for example,
we can see mysterious explosions in

distant galaxies that we would otherwise
miss.

And in microwave light, we can see all the
way back to the birth of our universe.

We have only just opened our eyes.