Richard Hammond's Invisible Worlds (2010–…): Season 1, Episode 1 - Speed Limits - full transcript

Using the latest high-speed cameras, Richard Hammond takes us on a journey beyond our eye's limits, letting us see secrets hidden in every element of our planet. A world where thin air can ...

The human eye - one of the most
powerful instruments on Earth.

On a clear day, we can spot the
smallest detail in the widest view.

But what the eye sees
is not the full picture.

Alongside the world we see
is a very different world.

An invisible world
of hidden forces and powers.

This shapes
every aspect of life on Earth.

Now, technology can open a door
on that hidden world,

revealing its mysteries,
and showing us the true wonder
of the world we live in.

In our vibrant, hectic world,
we think we spot everything.

But right in the midst
of this busy world, there's
a whole other world going on,

it's just that we can't see it.



To us, it's invisible.

Our eyes are too slow to see
everything that's really going on.

The world is full of things that
happen too fast for us to notice.

Things we miss
in the blink of an eye.

The blink of an eye takes
about 15 milliseconds,

and it takes the human brain
about 150 milliseconds
to process what we see.

We're not aware
of this time lag going on,

but in those few milliseconds,
there are things happening,

extraordinary things
that were never see.

This is the invisible world
of speed...

..where thin air...

can shatter rock

and water can tear through metal.

Where the fastest thing on Earth
is right beneath our feet.



And where we'd see spectacular
events that some thought were UFOs.

If we could stretch time,
we could solve some of the biggest
mysteries of our planet.

Now, using the latest camera
technology, we CAN stretch time,
making the invisible visible.

We can overcome the limitations of
our eyes to see whole new worlds.

Lightning. A billion volts
and hotter than the sun.

But there's even more danger
in what you CAN'T see.

This is Rapid City, South Dakota.

In the middle of America's
lightning belt,

it gets hundreds of
strikes every year.

But there is something strange
about the lightning here...

..something that's becoming
a bigger and bigger problem.

Something too fast to see.

Lightning travels at over
100,000 miles an hour.

So only with super slow-motion
cameras can experts begin to
understand what's going on.

When you view a flash in real time,
it's like seeing a title of a book.

You can see that there was a flash
there that reached the ground,

maybe it flickered a little bit,
but that's all you know.

You come and record this same flash
with these high-speed cameras,

it's like a novel.

It tells a unique story every time
you play it back. Incredible.

In slow motion, we can see what
gives lightning the shape that
launched a thousand horror movies.

Fingers of electricity
hunting for the ground.

And now, these high-speed cameras
are allowing us to catch something

completely invisible
to the naked eye.

The strange lightning that's found
not in the plains, but right
in the heart of Rapid City.

There's a storm brewing.

Specialist cameras set to record
at nearly 300 times slow-motion
are waiting to capture it.

And there it is.

At first it looks like
a normal lightning strike

but the technology
reveals something else.

Instead of lightning shooting
downwards, this lightning
is travelling upwards.

When I played this for the first
time, I was just blown away.

It was just amazing to see it.

And this strange, upside-down
lightning is powerful, it carries
more charge than normal lightning.

But what's really extraordinary
is that upward lightning
is created by us.

Because it's these tall transmission
towers that are triggering

the vast bolts of lightning
firing up into the clouds.

Now, you might think that because
it is going away from the town,

this lightning is harmless.

Unfortunately not.

When the upward bolt hits the storm
clouds, it triggers more lightning

that fires straight back down
to the city.

And it is not just here,
in Rapid City.

As we build more tall buildings,

this new form of lightning is
spreading across the world.

In this high-speed world, there are
surprises hidden in even the most
everyday things we think we know.

Take this, for example.

On the face of it,
that's just one small firework
designed to make people go, "Ahh!"

But in fact, there's an invisible
force at work here,

one hidden in all explosions,
and it's powerful enough

to destroy buildings
or tear through solid rock.

Even this little candle unleashes
a force too fast for us to see,

that reaches way beyond
the pretty sparkle.

And that's what
this special camera shows,

something our eyes can never see.

It's a shockwave -

super-fast, devastating, potentially
deadly, and yet it's just thin air.

I want to take a closer look at
this devastating force in action.

To do that,
I need to blow something up.

So, this rock face,
it's about 100 metres long.

That's what we're going to blow up,

which will mean shifting
about 20,000 tons of rock.

Up here on the top,
we're filling not one, but 20,
separate holes with explosives.

You see, our experiment is
a bit more sophisticated than just
creating one massive explosion.

Each one of these 20 separate
explosions needs to be

choreographed to go off
at 25 millisecond intervals.

That way, each explosion
will fragment the rock,

and open up a face that can then
be hit by subsequent explosions.

At least, that's the theory.

This whole event is going to be
over in about half a second.

So to stand a chance of seeing this,

we're going to need
to film it at high-speed.

We're using a remote trigger
with a short travel,

so I need to be 100 metres away
from the explosion - in that.

Yeah, I know.

But it does mean I'll get to
experience very much at first hand

the impact of 20 separate explosions
detonating within half a second

of one another to try and shift
20,000 tons of rocks.

So in that sense,
I'm lucky to be in there.

Nice!

Oh, yeah.

I feel safe.

So, I arm it with that.
BEEP

That means it's now armed.

Counting down from
five, four, three, two, one.

20,000 tons of rock,
gone in a second.

And I'm still safe,
which is a bonus.

That was quite a rumble.

I really felt that.

Yeah,
just to actually feel the earth move

because of something you have just
triggered, that's quite a sensation.

Yeah.

A little lie-down is needed.

But it's only when we slow down
in the film 40 times that

we can see more
of what just happened

and why I wasn't turned into mush.

There's a flash as
the detonation cable ignites.

And now we can see the blast going
off. One every 25 milliseconds.

But the real force is not the blast.

It's the shockwaves
that each blast releases.

Deep in the quarry face,
the shockwaves are forcing
their way through sheer rock,

eventually erupting at the top.

The shockwaves keep on
expanding outwards,

powerful enough to crumble the rock

and finally tear apart
the entire face.

But thankfully, not mine.

By choreographing the explosions,

we were able to drive and steer
the shockwaves through the rock,

rather than let them spill out
into the air around,

which is why
I was able to get so close.

Not sure I'd want to get
much closer.

So, how can a shockwave cause
such awesome destruction?

To find out, we're going to
trigger one almighty explosion.

We're going to attempt
to see a shockwave.

It'll be over
in the blink of an eye,

but high-speed cameras
will capture every millisecond.

At least, that's the plan.

First, thousands of pounds
of gunpowder are loaded.

That's a lot of gunpowder.

The fuse is set.

To be safe, everyone needs
to be over a mile away -

that's why they're running away
in pick-up trucks.

Except for these guys -

the detonators.

They'll be less than half
a mile from the blast zone,

which is why
they get the armoured car.

Everybody ready? Are you ready, sir?

Range control to security checkpoint,
are you clear? 'All clear.'

Obs one, are you clear?
'We're all clear.'

10/4, stand by for counting. I'll
say it again, stand by for counting.

Five, four, three, two, one...

In an instant, thousands of pounds
of gunpowder explode.

But the shockwave
is completely invisible.

So we need to slow it down
over 100 times,

and then watch it back repeatedly -
from several angles.

Stand by for counting. I'll say
it again, stand by for counting.

Five, four, three, two, one...

The fuse races towards the site.

In a thousandth of a second,
the gunpowder ignites.

In one millionth of a second
it changes from solid to gas.

And there it is.
Finally, we can see the shockwave.

A wall of intense high pressure
in the air.

It's travelling at over
300 metres every second.

So fast that anything in its path
is punched aside.

And now we can see amazing detail.

The shockwave reignites
unburnt fuel, triggering a
secondary shockwave at the tip.

It's the shockwave,
not the explosion itself,
that causes devastation.

In the high-speed world,
thin air can create brute force
and destruction.

But it can also allow us to do
some pretty amazing things.

OK, right, so go for the off, yeah.

A nice bit of back pressure as
you take-off, plenty of left pedal.

And a bit more.

That's it.

There she goes.

Now, bear with me,
I am still learning this.

Now, it's something that we take
for granted, but essentially

nearly two tons of helicopter
and me are being held up by air.

Just very, very fast-moving air.

The rotor above pushes air
downwards, that creates the lift
that keeps me up in the sky.

It's one of the basic principles
of aerodynamics.

But step into the world
of the invisible,

and this benign and useful force
suddenly looks very different.

These planes are flying close
to the speed of sound.

But at this speed,
the air moves so fast

it's about to become
a potentially dangerous force.

Slowed down by nearly 200 times,
just watch what happens on the wing.

At these super high-speeds,
the moisture in the air
suddenly condenses into water.

A cloud forms.

I know that doesn't sound
very scary - a cloud -

but that cloud is like
suddenly dumping
the weight of a car on the wings.

Only the most skilled pilots,
like these, can cope.

We may think that
we've conquered flight,

but compared to the natural world,

our mastery of the air
is basically rubbish.

Engineers have been wrestling
with the problem of flight

since the Wright brothers
first got airborne 100 years ago.

But it is only now, with the advent
of ultra-high-speed filming

that we can really begin to
understand some of the secrets

of the natural world,
which has, after all,

been working on the same problem
for over 350 million years.

Now, come on,
you've worked it out now.

It's a lot of practice,
it's a lot of years.

Yep, got there in the end.

The first creatures to fly
weren't birds,

they were insects.

For centuries,
their secrets were invisible.

Wing movements
lost in a blur of motion.

We're only now starting to get
the full picture.

The hummingbird hawk-moth
is revealed to be a model
of flying finesse.

With amazing control, it can
hover at a complete standstill,

perfectly poised to gather nectar.

But not all insects
are quite so elegant.

The bumble bee is an aerodynamic
mystery that had scientists baffled.

A big, fat body,
supported only by tiny wings.

Now, how's that supposed to work?

The confusion started over 70 years
ago, when a French entomologist

calculated that bee flight
was aerodynamically impossible.

Ever since, scientists have
struggled to understand just how

a bee's apparently random flapping
can possibly keep it airborne.

And, at first,
even seen in slow motion,

the mystery doesn't get any clearer.

Here she is,
lurching through the air.

She even has to use her legs
to balance herself -

elegant it's not.

The only way she's staying up
is by furiously flapping

at an extraordinary
200 beats every second.

That's why she's so round,

her chest is a mass of muscle
to power the wings.

No, I'm not trying
to set fire to them,

this smoke should help us see
what's happening.

As the bee beats its wings,

air, or in this case, smoke,
is pulled downwards.

This generates lift,

but not enough to keep
the stripy buffoon airborne.

Only in super slo-mo can we see
she's actually rather clever.

At the end of each downstroke,

she twists her wings over.

So, even on the upstroke,
the smoke is still pulled downwards,

giving her double
the amount of lift.

And you don't get that
with an aeroplane.

By looking into the invisible world
of high-speed,

human engineers are discovering
a range of animal secrets

they can use to develop
even better flying machines.

So, why do we miss so
much of what's around us,

when it's perfectly obvious
to other creatures?

A fly, for example,
can see 100 images a second,

allowing it to zoom around at top
speed and not crash into things.

To a fly, our world appears
incredibly slow...

..which is why, annoyingly,
I'm never going to catch it.

But what the fly has in speed,
it loses in detail.

Everything it sees is a blur.

We, on the other hand, have evolved
to see very fine detail.

But there's a trade-off -
our eyes can't do speed.

We process a lot of
information in any one scene,

but it does take time. So much time,
in fact, that the best we can do

effectively is take snapshots
of the world around us.

We take a look,
process the information,

take another look,
process that information, and so on.

Each snapshot lasts
just 100 milliseconds.

And unlike the fly,
our snapshots are very detailed.

So it takes time
to process each one.

Anything that happens in those
milliseconds while we're processing
information remains hidden.

It's as thought it's not there.

So, right now, everything's fine.

I can deal with all the information
coming my way, I can see colour,

yellow track, I can see the curve,
the shape of it.

I can even see the chain moving
to pull my little cart long.

No problem...at normal speeds.

But it's surprising how quickly you
reach the point beyond which

I can't process the information,
because as things get faster,

so strange things
begin to happen to our vision.

Now, it's not that I'm missing stuff

cos I'm looking the wrong way.

I just can't deal with
the information as it comes in.

There's just too much going on!

I can't work out what's what.

My vision hasn't suddenly gone
faulty, this is as good as it is.

The faster things move,

the less time we have to process
all the detail in the picture.

But as things speed up, eventually
the rate of incoming information

exceeds the speed of our neural
processors, and you can't see!

I'm not too sure my stomach
can process it either.

And when it gets too fast,
we simply can't see it at all.

Did you spot this?

When we start to see the things
that are usually invisible,

it shows us how extraordinary
our world really is.

Water becomes thick, elastic.

It even contains a powerful force
that can tear through sheet metal.

Nothing is quite what it seems,
even stuff we think is familiar.

It's not exactly a rare thing
for most of us, rain.

But venture into the invisible
realm, and suddenly the world
as we think we know it changes.

Take a simple raindrop, for example.

We all know that they form
a tear-shape,

fall through the air,
and then land on the ground.

Except they don't necessarily
do any of those things.

Looking at this downpour
with specialist cameras reveals
the surprising story of rain.

Every raindrop
begins as a perfect sphere.

As they fall, air resistance
causes the drops to flatten.

Real footage slowed down

shows that they're really,
well, wet hamburgers.

In fact, they never, ever form
the classic teardrop we imagine.

So much for
the raindrops' tear shape.

High-speed filming shows
what happens next to these
airborne hamburgers.

This rare sequence reveals
something quite extraordinary -

rain that simply vanishes.

Bigger raindrops can swell and
inflate like balloons

until they burst, exploding
into smaller and smaller drops.

Some of these tiny drops never
actually hit the ground,

they're just dispersed into the air.

But there are still enough
big drops left to land on us.

In the high-speed world,
water becomes thick...

..dense...

..an alien environment
that we struggle to get through.

Over time, a strong swimmer can
manage about two miles an hour.

But that's a crawl compared
to other mammals, like this fella,

the dolphin, who speeds
through five times faster.

But it's only in slow motion
that we can see

why the dolphin
is so much at home here...

..and why we aren't.

Water is 800 times thicker than air.

So thick that it pulls and
distorts our soft bodies as we swim,

causing drag, which holds us back.

Now watch what happens
to Mr Dolphin here.

The water doesn't distort his body
at all, passing smoothly over it.

That's because the dolphin has
much thicker skin, like rubber,

that stops his blubber flapping.

So, while we struggle
to make headway,

a dolphin is barely trying.

And when it needs to
swim even faster,
the dolphin makes it look easy.

Slowed down 40 times,

we can suddenly see things
invisible to the naked eye...

..like the way the water
flows cleanly around its
torpedo-shaped body

so the dolphin
can speed through effortlessly,

saving his energy for, well,
showing off, basically.

Yes, yes, very good.

Have a fish.

And if he can't be
bothered with all this,

he can hitch a ride on the surf.

But there's something
really strange about water,

and it's hiding beyond our sight.

Lurking in these warm, clear waters,
is an invisible force...

..capable of tearing through metal.

A force that is, even now,

destroying this boat.

To see this force in action,
we're going to need some help.

In this tank is a tiny creature,

but it's armed.

Hiding under the rock
is a pistol shrimp,

and it's packing a lethal weapon.

This crab is heading into trouble.

Our shrimp is ready for a scrap.

At first sight, it looks like he's
punching the intruder with his claw.

But, in fact,
something much stranger is going on.

Its weapon isn't exactly
the claw itself, not directly.

The weapon is invisible,

as I shall now demonstrate
with this paint brush.

I'm not getting in there with it,
it's armed.

Right...

Come on.
SNAP!

Oh! Did you hear that?

SNAP!

That noise is a big clue
as to what's going on.

It's too fast to see, so let's have
a look at it again in slow motion.

The sound we hear
is not from the claw itself

but from an amazing invisible force.

The claw snap happens so fast
it causes a high-speed water jet

which shoots forward
at almost 60 miles an hour,

fast enough to vaporise
the water and form a bubble.

And that's a lot more dangerous
than it sounds.

The temperature inside the bubble
reaches over 4,000 degrees,

and, as it collapses,
this massive energy is released

like a superheated shockwave,
stunning, or even killing, its prey.

The knockout punch
comes not from the claw

but from the super-hot power
of a bubble.

This incredible force
is called cavitation.

It happens whenever water is forced
to move at extreme speeds,

and it can do a lot more
than scare off a little crab.

Up to now,
it's been completely invisible.

Using ultra high-speed cameras,
we can finally see it in action.

This propeller is spinning so fast
it vaporises the water around
the tips of the blades...

..creating streams of
super-hot bubbles.

As they collapse, they release
a massive wave of energy...

..bombarding the propeller blades.

It's so powerful,

it can destroy the metal itself.

Cavitation ruined this propeller

after a single journey
across the Atlantic.

Our everyday world, familiar,
ordinary, even a bit boring.

But hidden beyond
the timescale of our eyes

lie truly amazing phenomena.

And some of the fastest of all
happen not in the air

or in the water,
but right under our feet.

The plant world lives
according to an entirely different
time-frame to ours,

which is why this all looks
very peaceful, calm, relaxing, even.

But, in fact, there's a war going
on. It's just that we can't see it.

By squeezing weeks into seconds,

we see plants locked
in a battle for survival,

competing for sunlight, space,
and for the attention of insects.

But plants don't just do slow.

This timescale according to
which the plant world lives
is exactly that, a scale.

And plants can exploit
the extremes at either end of it,

so when they need something to
happen fast, they can do fast.

Watch this.

You see?

No, you won't have done,
because it happens too fast to see.

We'll have to slow it down
to see what's actually happening.

This Himalayan balsam is
firing out seeds at an astonishing
six metres a second.

Flinging them in all directions
like a toddler with a plate of peas.

Sending them far enough to keep
its own patch free from competition.

OK, so what do you think is the
fastest accelerator on the planet?

A rocket?

A jet fighter?

A missile?

Nope. Thanks to the latest
in high-speed cameras,

we now know
it's something else entirely.

And it's found right here
in the British countryside.

The fastest living thing on the
planet is in this field right now.

It's not some supersonic
species of falcon, or a cheetah.

We're in Herefordshire, they
don't have them here anyway.

It's not those two, either. But
it's got something to do with them.

What it is, is right here.

Down, it's smaller,

it's down...it's right here.

Yeah, this. Well, not actually this,

but this horse poo
is home to hundreds of tiny fungi

and it is literally
the speediest thing on the planet,

in there.

Well, not exactly the fungi
themselves, but their spores.

Here they are,
just starting to appear now.

When these grow up,

they will be capable
of feats of acceleration
that the mind can barely comprehend.

These little beauties, pilobolus,

can do 0-20
in two millionths of a second,

and pull 20,000G,
which is a lot.

Astronauts on a space shuttle
have to cope with four.

Get anything past five G, pretty
much, and people start passing out.

Now watch the spores.

They're the black bits on the top.

At normal speed,
they seem to simply vanish...

..because they have one of the
speediest lift offs on the planet.

It's so fast that it's invisible.

It's only recently,
with the development of
ultra high-speed cameras,

that we've had any idea of
the incredible high-speed performers
hidden in humble horse poo.

Slowed down 10,000 times, we can
see them hurtling through the air.

It's so fast,
it's like us being catapulted
to 100 times the speed of sound.

All of which begs the question, why?

Why does a fungi that lives in poo

need to be the speediest thing
on the planet? Why?

Well,
for our fungal family to survive,

their spores need to get gobbled up
by a friendly grass eater.

This horse, for example.

But he won't eat grass from
an area around any pile of poo,

known, rather charmingly, as,
"the zone of repugnance".

Which it kind of is.

So the fungus has to
launch spores beyond that,

which means clearing
over two metres.

But there's a problem.

The air's too thick.

You see, the smaller you are,
then, relatively speaking,

the thicker the air gets.
Imagine this coin

were a tiny pilobolus spore.

There it goes.

But, to the tiny spore,
the air is thick, like honey.

And would stop it in its tracks.

The only solution
is to go fast enough

to power through the thick air into
the fresh, poo-free grass beyond.

And that's exactly
what the fungal spores do.

Underneath each tiny head,
an explosive bubble
of liquid pressure builds up

until, finally, it bursts,

launching the spore at its tip
more than two metres away.

I know, it's impressive.

Yep, your head's really heavy.

Close-up, you're quite ugly,
you know that, don't you? Get off.

By looking into
the invisible world of high-speed,

we discover extraordinary events,

even in something as ordinary
as a garden pond.

These little creatures,
water striders,

had long been a bit of a mystery.
Nobody could work out quite how

they could propel themselves across
the surface of the water so quickly.

They can scoot forward
nearly two metres every second.

And they're achieving something
of biblical proportions,

actually walking on water, skating
across the surface without sinking.

Only by seeing what time usually
renders invisible to us

can we understand
what's really going on,

and it's got something to do
with what's about to happen here.

Normally, this is too fast to see.

But watch what happens
in slow motion,

as the droplet of milk
hits the water surface.

Instead of breaking,
the water surface stretches,

bouncing the milk drop
back up into the air.

The water behaves as if it has
a thin elastic film on the surface.

It's called surface tension.

And it's this elastic membrane
that allows the water strider

to stand on the water,
rather than sinking into it.

He's also using that
elastic surface tension

to catapult himself across the pond
at the equivalent of about 600mph.

In coloured water,
we can see the force

of the strider's legs
as they push across the surface.

The high-speed artist
of the invisible world.

To us, this is just a pond.

But to the water strider,
it's a giant trampoline.

Now we're going even further,
looking far above us

to reveal the invisible secrets
on the very edges of our world.

At the edges of our world,
high above our heads,

are even more astonishing events.

The night sky might look calm,
tranquil, the silvery moon,

a few stars, all of that,
but there are other things up there,

things so strange
we weren't even sure they existed.

Our final journey
takes us on the hunt

for one of the most elusive events
of the invisible world.

We're attempting to find
a spectacular lightning formation

50 miles wide, but so fast
it's virtually invisible.

Centre 6775 with you
at flight level 4-0-0.

'Take off from 6775 Centre.'

Brief glimpses have
been mistaken for UFOs.

They're called sprites.

Now a team of scientists is heading
high above the clouds, trying to

catch them in the air on high-speed
cameras for the first time.

We're closer to the sprites,
which is good,

but since we're closer and we don't
know where they're going to happen,

that makes it a little harder.

Conditions have to be just right.

After years of planning,
tonight is the night.

No pressure then(!)

1,000 miles away,
a massive storm is brewing.

This little plane's
flying right into it.

We're headed to Meridian,
Mississippi now, and past that,

we're going to head over toward
Little Rock, Arkansas, and then

we're going to go straight up
toward Des Moines, Iowa.

About two hours to get there.

We'll have four hours
to loiter around the storms

for the sprite pictures in the back,
and then two hours back home.

So we'll be airborne
about eight hours tonight.

The mission takes place
in almost total darkness.

Any stray light makes it
harder to detect sprites.

A low-light camera
and image intensifiers
will help us see in the dark.

I've also packed some carrots.

Sprites are electrical discharges
like normal lightning,

but very different.

The real difference is
how brief the sprites last.

Normal lightning can last,

if you count all the strokes
together, maybe half a second.

Sprites are a lot shorter
in duration.

The plane's flying
higher and higher.

Now at 50,000 feet,
close to the border with space.

See that? That's Jupiter.

With flying at this altitude,
it's the clarity of the air.

The visibility is forever.

Getting close now.

There's a storm building way below.

It looks to me like we're
getting all the lightning

on our back side right now,
so is it possible to turn
ten degrees to the left?

As the plane turns,
the storm unleashes its fury.

These are perfect sprite conditions.

There's no time to lose.

Do you think we should go up?
Don't know.

It won't hurt the intensifier.

The high-speed cameras and
image intensifiers are prepared.

10,000 frames a second,
50 micro-second integration time.

They're fixed on an area
just above the storm itself.

Gain is 60,500,

the aspect is zero, elevation
is minus four. Do we go again?

Trying to catch
one of the most elusive phenomena
in the natural world.

A sprite. There's something.

I think that was probably outside
the field of view, I'm not sure.

It could have been a sprite.

And the storm's about to die.

We're now at minus four
degrees elevation.

And then... Sprite.
We're looking. Yeah, we got it.

It looks like there's two of them.
I think he got them.

A vast column of light,
20 miles tall.

It dwarfs the city below.

A spectacular formation,
trailing globes of light.

Each one is as bright as Jupiter.

These amazing high-speed images
have been captured from the air
for the very first time.

You and I live on seconds or minutes
or maybe even years of timescales.

And sprites are
one one-thousandth of a second.

It makes you realise how
different the world can be.

This vast display happens
in our skies all over the world,

but we're completely unaware of it.

Although it is reckoned that
some reports of UFOs

might actually be glimpses of these
vast, super-bright round flashes.

Sprites aren't just spectacular.

They're also one of the greatest
secrets of the invisible world.

Thanks to high-speed cameras,
we've been able to see things
we never even dreamed of.

But of course, that is
not the end of the line.

Who knows what else is going on
right now that we can't see - yet.

Subtitles by Red Bee Media Ltd