Original subtitles

(dramatic music)

It's the beginning of a new era in astronomy.

For the first time, scientists have discovered

ghostly particles that are not just extraterrestrial,

but extra-galactic.

They come from millions of light years away

from where stars explode or super massive black holes

swallow cosmic matter in tremendous vortexes, neutrinos.

They are the most common elementary particles that exist

and the most mysterious.

Every second, 100 billion of them

race at a speed approaching the speed of light

through our bodies, without our ever noticing.

They move unimpaired through the universe

because they can fly easily through anything.

(upbeat music)

For me, the neutrino is the closest thing

to nothing we can imagine.

It has zero size, zero charge, mass very close to zero,

and it interacts so weakly with everything,

but somehow or other the neutrino isn't nothing.

It might be the key to the universe.

For astrophysicists,

the universe is one huge laboratory

in which most things still have to be discovered.

The matter of which the stars, planets,

interstellar gas clouds, and humans are composed

only accounts for a mere 5% of the universe's mass.

The rest is an enormous unsolved puzzle.

The human eye is woefully inadequate

to see everything in the universe.

Astrophysicists are looking for apparatus

that will help them investigate

the tremendous events in the cosmos

for which they have any number of theories,

but precious little concrete information.

(speaking in foreign language)

They are not simply neutrinos,

in our case, neutrinos with particularly high energy.

They are neutrinos conveying a message.

They're ambassadors.

They tell us something about the object

from which they come to us.

This object must be something

in which incredibly high energy is released,

many times higher than that in the sun.

We're looking, for instance,

at neutrinos from the destructive processes of dark matter.

Possibly these neutrinos will give us

an indication of what dark matter is.

(light booming)

(mellow music)

10 years ago, an international team of scientists

started to build a gigantic detector

to catch these high energy neutrinos

in one of the most remote places in the world,

the South Pole.

(engine whirring)

Deep in the ice, the scientists are looking

for the flashes of light that a neutrino releases

when it collides with matter.

With a mobile drilling station,

the research team has melted countless holes

kilometers deep into the Antarctic ice cap.

Here, the ice is so deep and pure

that the detector which measures a cubic kilometer

has sufficient space and ideal conditions.

A hot water drill, which draws down its own weight

as it melts the ice,

has prepared the way for photo sensors

in the crystal clear ice.

The other layer of the ice sheet consists of snow.

The snowflakes change

as they are pressed down deeper and deeper,

over many thousands of years

from graceful ice crystals to compact transparent ice.

The meter high flakes are transformed into firn,

a layer of compacting ice.

More and more snow presses the air out of the firn.

It becomes denser and even more compact

until finally it is a body of ice, almost free of air.

The scientists have introduced photo sensors

the size of basketballs into the ice

on separate strings like threaded beads,

up to a depth of two-and-a-half kilometers.

Within a single day, the drill hole freezes closed.

(people murmuring)

(upbeat music)

(people clapping)

When the work's completed,

a cubic kilometer of ice is full of sensors.

Yeah, there we go.

The gigantic detector is now ready.

Deep within the crystal clear ice,

where it is pitch dark,

thousands of highly sensitive photo sensors

wait for minimal but far reaching traces of light.

And these traces only occur

when a neutrino collides with an ice atom.

In 2013, scientists first discovered

conspicuous traces of light in the IceCube detector.

(speaking in foreign language)

We can't catch the neutrino itself.

It interacts with matter very rarely.

A reaction to that kind only occurs in our detector

if we are very lucky.

Then it reacts with an ice atom

and releases secondary particles,

which moved hundreds of meters through the ice.

Behind them, they draw a ball of light,

which is called Cherenkov light

after the man who discovered it.

And it's this that we identify with the IceCube.

We have succeeded in identifying high energy neutrinos

for the first time, Ernie and Bert.

They had such high energy that it was extremely unlikely

that they were created in the Earth's atmosphere.

These neutrinos must've come from outside our solar system.

When a cosmic neutrino, which is much smaller

than the nucleus of an atom collides with an ice atom,

it leaves behind a trace of light

that spreads over several hundred meters.

The scientists called their discoveries Ernie and Bert,

the breakthrough, after decades of research.

(upbeat music)

All over the world,

scientists are searching for these messenger particles

from the distant universe.

Also on the other side of the planet, in Europe,

a research institute on the French coast,

southwest of Toulon,

is the base for a tremendous Mediterranean project.

This building was constructed in the 19th century.

Now it captures the data of minuscule flashes from the sea.

Here, researchers are trying to decode

the neutrinos' oscillations,

their transformation into three so-called flavors

on their flight path.

ANTARES, the small prototype of a neutrino deep sea detector

off the coast of southern France.

It's already sending data.

It's still a prototype.

Within a few decades, a cubic kilometer

large detector field is planned, KM3NeT.

Each box corresponds to one of the detection strings.

Each cross represents the height

and the time of the photon that was detected.

So on these displays, we can see a kind of time history

of the counting rates on the optical modules.

The main source of light that we detect

is from the natural radioactivity of the salt,

the potassium-40 isotope of the salt,

emits a little beat of particle, which emits light.

So most of this light is just due

to this natural radioactivity in the sea,

but every now and then,

we may get a fluctuation or a spike in the time chart,

and that is associated with bioluminescence activity.

In the sea, the organisms have evolved

to emit their own light by luminescence.

And if one of those organisms

comes close to the telescope,

you could even bump into the telescope

and go ouch and make a flash of light in reaction.

(dramatic music)

(speaking in foreign language)

The aim of our research into bioluminescence

is the connection between bioluminescence values

and the physical parameters of the Mediterranean,

which is a small ocean.

Especially the temperature and the salt content

have a great effect on the behavior,

the movement patterns, the mixing ratio,

and currents of the water masses.

We want to understand these dependencies better.

KM3NeT will be a multifunctional

measuring instrument in the sea,

supplying biologists, geologists, and physicists with data.

Apart from neutrinos,

the scientists can already detect specific species

of whales and dolphins in the Mediterranean.

(speaking in foreign language)

Here's the expired time,

and in the verticals, I can read the sound frequencies.

(speaking in foreign language)

Each time a signal is detected,

I see a color code and hear a click.

So I can hear short broadband signals, clicks, in real time,

a few milliseconds after the dolphins or whales,

especially toothed whales and sperm whales, transmit them.

(dramatic music)

20 years ago, we started the development

of the ANTARES telescope.

It took some some while to learn the tricks of the trade

of how to build very large infrastructures

very deep in the sea.

ANTARES was in fact 12 detection strings,

but the project that we're building now, KM3NeT,

will be many hundreds of strings.

So this will dramatically increase the chances

and essentially guarantee that we will be able to have

unambiguous detection of cosmic neutrinos.

(upbeat music)

Neutrinos are all around us,

but we have no idea where they come from,

these elementary particles

that have a thousand times more energy

than those from the world's largest particle accelerator,

the large Hadron Collider in Geneva.

(speaking in foreign language)

The most trivial neutrino source is humans.

All of us have potassium in our bodies.

A radioactive isotope of potassium, potassium-40,

undergoes beta decay, which produces neutrinos.

Our bodies transmit between

4,000 and 5,000 neutrinos per second.

Particle and astrophysicists, however,

are much more interested in solar neutrinos,

which we've already identified.

In fact, on every square centimeter,

say on every fingernail,

60 billion solar neutrinos arrive every second,

and they fly through us,

irrespective of where we're standing,

facing away from the sun or towards it.

Some 60 billion neutrinos race

through every square centimeter,

all over the earth, every second.

The sun burns hydrogen in its core

at a temperature of 15 million degrees Celsius.

Light particles and also neutrinos are emitted.

The sunlight we see has required thousands of years

to pass through the sun's successive layers.

Only the neutrinos leave the core immediately.

Just eight minutes after their creation,

they reach the earth.

But these are low energy neutrinos.

(speaking in foreign language)

We are looking for neutrinos that come to us

from entirely different processes,

not from nuclear reactions as in the sun,

but from massive accelerating processes,

cosmic accelerators similar to our Geneva accelerator, LHC,

but accelerated many times faster,

so with much higher energy.

That's why we're hoping for information

from the cosmic neutrinos,

which we can't derive from any other source.

(mellow music)

Neutrinos are a small part of the cosmic radiation

that constantly rains down on the Earth's atmosphere.

We've known about this radiation

for more than a hundred years,

but where and how these particles originate

is still a puzzle.

All we know is that

it's a highly energized particle radiation,

comprising mainly protons and atomic nuclei.

(speaking in foreign language)

The charged cosmic particles

are diverted into magnetic fields.

That's to say they meander through space,

and as they come from a particular direction,

they get so distracted that they arrive on earth

from the opposite direction.

So we can't trace their route or their source.

Their path is distorted.

So we need neutral particles which don't get distracted.

That's why neutrinos are ideal for us

because they are neutral,

because they come from compact objects

from which light can't escape,

and because they can simply fly through matter.

They're distracted neither by stars nor specks of dust.

(mellow music)

Here in the Mediterranean,

the KM3NeT detector is being constructed.

It will be built in three sections,

one of them off the coast of Italy,

another off the coast of France,

and the third off the coast of Greece.

They will be four kilometers underwater

and digitally linked to form a giant detector.

In its maximum extension

KM3NeT will be 10-cubic kilometers large.

Whereas ice is the detecting medium

of IceCube at the South Pole,

the detecting medium here will be water.

But deep sea conditions make entirely different demands

on the planning and construction of the detector.

To read the data from the water,

the scientists are installing an infrastructure

on the seabed which will gather the data,

bundle it, and transfer it via special, deep sea cables

to the analysis stations on the coast.

(upbeat music)

With an instrument the engineer's call Worm,

which uses extreme water pressure,

they dig a deep channel into the upper layers

of shell and stones until they strike

a harder layer of rock.

On this solid foundation, an accompanying diver

lays the cable and immediately covers it

with shell, limestone, and mud for protection.

To pile the detector and to transfer the data

from the detector to the shore,

we have just a submarine cable

which is a telecommunications cable.

Then to actually transfer the data,

we use these optical fibers.

So in the KM3NeT cable, we have 36 optical fibers.

To protect the cable from the possibility

of boat anchors damaging the cable,

we have this extra armor plating

around the cable, two layers,

an inner layer here and a thicker outer layer here.

Further out to shore, it's a single armor,

and then when it's in deep water below a thousand meters,

there is no protection.

It's just the polyethylene cable.

(mellow music)

Zeuthen, south of Berlin, is the location

of one of the leading centers of neutrino research,

the German electron synchrotron, DESY.

This is where a team of particle physicists

developed the sensors

from which IceCube at the South Pole is constructed.

(speaking in foreign language)

In this glass sphere, you see a photo magnifying tube.

It's held in this optical module,

and it's very light sensitive.

As soon as a single photon falls on this side,

it produces a tiny electrical current.

The electronic module here in the upper part of the sensor

emits the current.

This is the glass sphere that protects the sensor

from the enormous pressure of the deep ice.

And inside, we have the electronic module,

which amplifies the tiny electrical current,

digitalizes it, and then sends a signal

to the IceCube laboratory on the surface.

(dramatic music)

Thousands of synchronized sensors

measure the precise time and strength of the light event

and communicate the data.

In their laboratory,

the researchers are already working

on the next generations of light sensors.

They should be cheaper, simpler, and more efficient.

One idea is to conduct

the Cherenkov light through coated tubes.

The scientists are looking for ultraviolet light.

The post-doctoral student Jakob van Santen

is getting ready for his first assignment at the South Pole.

(speaking in foreign language)

You have to be really fit to fly to the South Pole.

I have to get a thorough medical checkup.

When I get the okay,

I'll set off for Christchurch, New Zealand.

I'll have to wait there for quite a while

until the weather conditions are right.

Then, I'll fly eight hours to the Antarctic coast,

and then one-and-a-half hours to the South Pole.

I've been working on the IceCube project for a long time,

but I've never seen my experiment.

I'm really looking forward to that.

And it's great to be traveling

to a place which only a few people have visited.

(dramatic music)

The journey to the South Pole

is an adventure for the young scientist.

The Antarctic is larger than Europe.

It's surface includes land, continental ice,

and a gigantic ice sheet.

98% of the region is covered in snow and ice.

In summer, the ice surrounding the southern-most continent

melts to three million square kilometers,

one-sixth of its winter surface.

Because of the altitude of its terrain,

the extremely low temperatures, and low precipitation,

the Antarctic is also one of the driest regions,

in fact, the world's largest desert.

It's many days before van Santen

finally reaches the Antarctic.

He flies the last leg of his journey to the South Pole

in a U.S. Army supply plane.

He lands on the ice sheet at an altitude of 3000 meters.

It's summer here, and it's high season.

Researchers come to the South Pole in summer.

Only a skeleton crew remains during the dark cold winter

to keep the detector running.

Everyone who comes here is excited to reach the South Pole,

but some suffer from altitude sickness

from the moment they arrive.

It takes a few days to acclimatize.

For the researchers,

the new Amundsen-Scott South Pole Station

is an oasis in the middle of the ice desert.

It guarantees their survival.

The station can accommodate several hundred people.

Everything here is simple and practical.

(wind whooshing)

But Scott and Amundsen, who were the first

to reach the South Pole more than a hundred years ago

would be astonished by the comfort and technology.

This is an astrophysics hotspot.

Deep in the eternal ice,

the researchers are discovering cosmic light signals.

IceCube is searching for neutrinos

that have flown through the earth,

ones that entered the Northern Hemisphere.

Ones that entered the Southern Hemisphere

are looked for in the Mediterranean,

for only neutrinos can fly through the earth.

(upbeat music)

The KM3NeT detector will also search for particles

that have traveled through the earth.

Since the Mediterranean is more than 5,000 meters deep,

Catania, on the east coast of Sicily,

is an ideal spot for a research station.

A team of European scientists is here

to install the first section of the detector on the seabed.

Physicists have adapted the structure of the photo sensors

to deep sea conditions.

Water pressure, salt, and sea currents

are formidable challenges.

The sensitive electronic module has to be protected

to make the most precise measurements at any moment.

(speaking in foreign language)

The biggest problem is that these objects

have to be placed at a depth of 4,000 meters in the sea.

Everything has to be correct

because it's very difficult

to pull them back up from the sea to repair them.

So everything has to work perfectly

before the mission begins.

It takes a long time to produce and test each optical module

before it can be released and deployed in the sea.

(light electronic music)

(speaking in foreign language)

This kind of physics, the astrophysics of neutrinos,

is a completely new branch of physics.

It's absolutely innovative.

With these neutrinos, we'll make a new map of the heavens.

The physicists register the sensors to sort the data

they will receive out of the depths.

(dramatic music)

In the Scott-Amundsen Station at the South Pole,

Jakob van Santen is now feeling at home.

He can reach the IceCube on foot.

(speaking in foreign language)

It's a beautiful day, almost no wind,

summer temperatures of minus 30 degrees Celsius,

glorious sunshine.

The station is about 500 meters behind me,

and in front of me, it's only about 500 meters

to the IceCube laboratory.

I'm going there now to see how our detector is doing.

(dramatic music)

(snow crunching)

(speaking in foreign language)

These rods and flags are the only parts of the IceCube

you can see on the surface.

Most of the detector lies

one-and-a-half kilometers under my feet.

IceCube is a superb neutrino detector,

a gigantic high-tech ice cube,

(upbeat music)

buried two-and-a-half kilometers deep

in the eternal ice at the South Pole.

It's dark down there, and the ice is extremely pure.

Light is able to illuminate IceCube without distractions.

The eyes of the telescope watch

for the tiniest flashes of light.

5,200 photo sensors register

the weak light of the particle tracers,

which can travel many hundreds of meters through the ice.

When light signals are discovered, the sensors

transform them into electrical signals and conduct these

along the steel cables to the surface, to IceCube,

into the brain of the telescope.

Hello.

The first computer center

has already been installed in IceCube.

It registers all the data from the ice,

filters it roughly,

and then sends it to research centers all over the world.

Data from each of the more than 5,000 sensors in the ice

is gathered here.

This is the detector's control center.

It receives its power from here,

thousands of meters of cable

and cupboards full of computers.

Day and night, a small team of scientists

monitors the electronics in the IceCube.

I'm hired to keep the detector running.

So, whatever happens, I have to solve it.

This makes me happy

because these lights you see in the back,

if you see green, yellow, red,

then IceCube is taking data.

It's beautiful, eh? Yeah.

Very photogenic too.

I've been taking a lot pictures here of the cables.

(upbeat music)

To keep the detector running,

some of the scientists remain on the ice during the winter.

Then it is minus 70 degrees Celsius here and always night.

The sun stays below the horizon.

Only the moon follows its regular course.

This is perfect for viewing

the iridescent polar lights,

ionizing solar wind that meets the earth's atmosphere

and is diverted to the poles.

But now during summer at the South Pole,

when it's winter in Europe, the sun never sets.

It circles the pole at a fixed distance to the horizon.

The rhythm of day and night is suspended.

The day has 24 hours of sunlight,

and you can't orientate yourself on the sun's position.

It's just a single day that never seems to end.

Jakob van Santens' trip to the high-tech detector IceCube

in the Antarctic ice ends after 10 solar days.

(upbeat music)

A large computer farm in the grounds of DESY near Berlin

is both a modern memory and a gigantic computer.

The data from IceCube at the South Pole

is transmitted here by satellite.

Disruptive signals and other influences are filtered out.

(speaking in foreign language)

We do this for billions of events in IceCube

and fish out the rare events of cosmic neutrinos.

Data analysis is a very complicated process.

Where did the neutrino interaction

take place in the detector?

How much energy did the event have,

and what direction did it come from?

It's like looking for the needle in a gigantic haystack,

looking for neutrinos that have so much energy

that they could have originated outside our galaxy.

The scientists continue filtering

the countless events in the ice

until they come across the decisive light signals.

(speaking in foreign language)

This is the raw data.

We see the whole detector,

but not in real time, much slower.

I've only read out one second here,

but that's 1000 times slower than in real time.

Switch to real-time please.

Then the clip lasts one second and flashes madly.

Filtering the data more and more,

the researchers arrive at their goal.

The strongest light trails in the ice

have a diameter of up to 600 meters,

a 600-meter long light trail left by a particle,

so small that it's invisible.

(speaking in foreign language)

Now we really only see a trace.

Here, the trace clearly passes through the detector,

a myon producing Cherenkov radiation, no question.

Ernie and Bert are no longer alone.

Since discovering them,

researchers have been able to identify

other cosmic neutrinos.

The one with the most energy to date,

they have named Big Bird.

(speaking in foreign language)

We are hoping to be able to identify

the sources of these high energy neutrinos

as soon as possible.

The big question is how is this cosmic radiation produced?

How has it accelerated?

What are the cosmic accelerators that must exist?

I hope I don't have to spend the rest of my life

researching these questions,

but I definitely want answers to them,

the sooner, the better.

Downtown Berlin, location of the Zeiss Planetarium.

(dramatic music)

This is one of Europe's largest planetariums,

and the city administration is making it

one of the most modern.

The news of the extra-galactic neutrinos

fascinates the director.

To show them in the planetarium dome at the reopening

would be sensational.

Planetarium Director Tim Florian Horn

is a specialist in visualizing cosmic phenomena.

Using the most modern projection techniques,

he wants to make the latest developments and discoveries

intelligible to his visitors.

The Berlin Planetarium is a modern theater of science.

(speaking in foreign language)

Whenever anything new is discovered,

we want to talk about it and show it.

We can help people understand neutrinos best

if we can show their path through the cosmos.

That works very well in the planetarium

because our audience gets an idea

of the enormous distances in the universe.

(upbeat music)

(speaking in foreign language)

In real time, of course, they'd need months to fly

through the solar system,

so we have to suspend some natural laws.

We fly faster than the speed of light

to a place where in reality,

we would be destroyed by radiation.

If we ventured beyond our Milky Way,

we wouldn't be able to see other galaxies

because our eyes weren't created for that.

It's a narrow path we're treading.

We want to be scientifically correct,

but also intelligible for the audience.

So we have to make compromises in scientific accuracy

in the interests of intelligibility.

Basically we're a translation office for science.

To visualize the newly discovered neutrinos,

Horn meets up with a neutrino researcher,

Christian Spiering,

and a visual artist in the animation department

at the Potsdam Babelsberg Film Studios.

Their aim is to bring a cosmic neutrino to the screen

to make the discovery of an invisible object

comprehensible to a wide audience.

None of them knows what a neutrino really looks like.

(speaking in foreign language)

If we want to represent neutrinos, what can we show?

How do we conceive of a neutrino?

How might it move through the universe?

(speaking in foreign language)

I can only imagine how a neutrino moves,

and I imagine something like the trail of a jet plane

without seeing the plane itself.

I'm really only interested in how and why it flies its path.

Or I simply imagine a neutrino as the Greek letter nu.

That's enough for me.

Basically, I only see a formula.

On this issue, I ask myself where do they come from

how do they move, how do we show that?

(speaking in foreign language)

I'll make a suggestion.

I'm the neutrino.

I fly through the room.

Yes, a subjective flight might be the answer.

I race through the universe, various galaxies approach,

I leave them behind, then comes empty space,

just empty space.

Then at some point, our galaxy turns up

and then a blue sphere in the distance,

and that's the earth.

So far, Spiering has only thought of neutrinos

as particles without a shape.

The visual artist presents him with various ideas.

(speaking in foreign language)

That's more like an atomic model,

certainly not a neutrino in my understanding.

For me, a neutrino is more like a point

without structure, very tiny.

Okay, next suggestion,

a model that shines and appears to be intangible

with an external oscillation.

(speaking in foreign language)

That looks more like friendly elves,

oscillating around a green sphere

with green vibrating bands.

I understand.

(speaking in foreign language)

This one's interesting, out of focus.

It makes me think immediately of solar eruptions.

Of course, we also have the problem

that certain images are already familiar.

This one probably looks like Star Trek.

It wafts around indecisively in space.

(speaking in foreign language)

And it looks very wound up.

Yes, very excited neutrino.

(speaking in foreign language)

Previously, I saw something interesting

in the computer preview,

a sharply defined sphere rather than like a billiard ball.

If those edges could fray out or blur,

I think we would be closer to the ghostly particle.

For me, it's just a bit too big in relation to the screen.

No problem.

Yes, like that, let's try that.

(dramatic music)

In the Center for Particle Physics in Marseilles,

the French research team is getting ready to install

the first KM3NeT detector chain.

These are the eyes of the telescope

and the photo multipliers are very, very sensitive to light.

They can catch just one single photon.

The human eye actually requires about seven photons

before you can trigger that you've detected something,

whereas these are much more sensitive than the human eye.

And we need to measure the position where the photon arrives

on the detector with a few centimeter precision.

But of course, in the bottom of the sea,

we have the sea currents and in fact,

everything is slightly moving.

And so inside the optical module,

we have some very precise compasses

which measure the rotation of the sphere

and its inclination in all directions.

As soon as a neutrino hits

the nucleus of an atom in the detector,

it races on as a myon.

The myon emits light

and activates the individual senses on its flight path.

From the direction of the flight path,

the researchers can reconstruct the position of its source.

The amount of the light that we detect in the telescope

actually depends on the energy of neutrino.

So if a low energy neutrino was to interact,

there wouldn't be very much light,

whereas, when it's a very high energy event,

the whole detector will be lit up like a Christmas tree.

KM3NeT will be a powerful, deep sea detector,

the counterparts of IceCube in the northern hemisphere.

Each detector string is 800-meters long

and carries 18 sensors the size of basketballs.

So, if you were able to walk around on the seabeds

amongst the forest of detectors,

I think it'd be quite an impressive sight to see.

The telescope is not rigid.

It floats on the water current.

So every sensor has to continuously redefine its position.

That's the only way the researchers can determine

the direction of the neutrinos.

Back to the animation studio.

From the planetarium,

Tim Florian Horn has brought a software program

that can simulate the known universe.

In these vast spaces, the team tries to create

a dead straight path for the neutrino

from its source to the earth.

(speaking in foreign language)

A graphic card or a computer system can't represent

these large scales sensibly.

We have to be a bit cunning.

We'll compress the various coordination systems,

and we'll fly much faster than light.

When we're crossing matter,

whether it's the earth or an asteroid,

it would be good to try and zoom in on the atomic level.

I mean the level where, as a neutrino,

I only see an atom in front of me,

the nucleus in the center with a few electrons circling it.

Because at the end of the day,

an atom is an empty system

through which the neutrino flies completely unhindered.

Basically the whole of earth consists

of these empty systems.

And that's why it's porous for the uninvited neutrinos.

The atomic level should show why the neutrino

can fly unhindered through walls and whole planets,

a flight through the void.

In Marseilles, the researchers are preparing

to transport a detector string.

(speaking in foreign language)

Here, we have the structure we use to install KM3NeT

at a depth of four kilometers in the Mediterranean.

The KM3NeT sensor lines stretch hundreds of meters high

vertically from the seabed.

800 meters when set for the higher energies

and 200 meters high for our setup here in France.

But before installing these vertical structures,

we first wind the cable, which is a flexible cable,

onto this vertical structure.

Every action is carefully planned and tested several times.

The scientists roll a string

with the census spheres into a big ball.

They have developed a special anchor

to secure it on the seabed.

The final step in the construction hall

is to load the rolled up string onto the yellow anchor.

The first sensor chain is ready for shipping.

Together with the anchor, it's loaded and sent off.

A research vessel transports it 40 kilometers off shore.

Tonight, the first KM3NeT string is due to reach

the bottom of the Mediterranean

at a depth of three-and-a-half thousand meters.

(upbeat music)

Slowly, at a speed of 12 meters per minute,

the anchor and sensors sync onto the seabed.

They are accompanied by submersible robots,

steered by engineers on board the research vessel.

Four-and-a-half hours later, the load reaches the bottom.

Robotic arms attach cables linking the anchor

with the deep sea infrastructure

that transmits energy and information

to the coastal station.

Then a buoy hoists the frame.

The sensor string unwinds vertically from the metal frame

like wool from a ball

and releases the individual photo sensors

to their specific final positions.

Assembling the first detector string is successful.

Many hundreds more will follow.

Soon, KM3NeT will also be able

to identify extra-galactic neutrinos.

(upbeat music)

In the Berlin Planetarium,

the researcher animation team wants to take a look

at its first results, a cosmic premiere screening.

Scientists view the universe as a gigantic laboratory

for testing the validity of the basic laws of physics

and to investigate regions

in which gravity, density, and temperature

are extremely high,

there where stars explode or implode,

and a black hole is created.

A cosmic explosion in a gigantic particle accelerator,

a million light years away,

an enormous jet sent out by a gigantic black hole

in the heart of an active galaxy.

These jets can reach hundreds of thousands of light years

into intergalactic space.

They accelerate the cosmic particles,

thereby producing neutrinos.

A neutrino flies slightly slower than the speed of light.

Since it comprises only a smidgen of matter

and isn't charged,

other particles don't decelerate it

or distract it from its flight path.

So it can pass through everything

without risking a collision.

Atoms, of which our bodies are made,

consists of more than 99% empty space.

Between the nucleus at the center

and the even tinier electrons circling it,

there's a great deal of space for the neutrino

and nothing but an electrical field.

But unlike most other particles,

the neutrino doesn't register electrical forces.

It has to collide directly

with a nucleus for it to be stopped,

and that occurs very, very rarely.

This rare event can only be discovered

with the aid of gigantic detectors.

Only by chance,

and with a slight risk estimated by the scientists,

does a neutrino strike an atomic nucleus.

Now these extra-galactic neutrinos

have been identified for the first time.

Ernie and Bert are the mega stars

of astro and particle physics.

(speaking in foreign language)

In discovering cosmic neutrinos,

we have opened a new window.

However, we haven't opened it fully, just a crack.

We know there's something there,

but we haven't mapped this new landscape yet.

(dramatic music)

(speaking in foreign language)

When we find more of these particles

and trace them to definite sources,

we'll be able to create a mosaic,

and then we'll be able to say

how these sources really function,

how the wildest machines in the cosmos work.

Modern physics shows that the behavior

of elementary particles at the smallest level

and the development of the universe as a whole

are inseparably linked.

With models and theories, scientists are trying to gauge

and extend the boundaries of physics.

Neutrinos will help to prove those theories.

(explosion booming)

So, our main goal will be to discover

a single point-like source of neutrinos,

so that could be sources like black holes,

accreting matter,

collisions of black holes or supernova explosions.

To be sure that we detect such a source,

we would need something like 10 neutrinos,

pointing from a single location in the sky.

(dramatic music)

History has shown that every time

you switch on a new telescope,

you should not be surprised to have a surprise.

(speaking in foreign language)

If there are highly developed civilizations

perhaps they don't want to be spied on

by underdeveloped civilizations like ours.

Maybe they decided not to use

electromagnetic waves to communicate,

but something quite different, for instance, neutrinos.

Just imagine, that would mean that neutrinos are something

like Morse code from extraterrestrial civilizations.

(upbeat music)