Horizon (1964–…): Season 45, Episode 11 - Can We Make a Star on Earth? - full transcript

The sun is 93 million miles away.

And yet it can illuminate
the surface of the Earth.

You can fit a million Earths inside.

The surface temperature
is 6,000 degrees.

At its core, it's 15 million degrees.

It loses 4 million tons
of mass every second.

That mass is turned into
energy and we feel it as heat.

The sun is powered by the
strongest force in the universe.

And, as a physicist, I believe that
our long term future depends on us

learning to do the same.

That's why, across the world,
teams of engineers and scientists



are stepping into the unknown.

You are looking inside the Star Chamber.

We're gonna discharge
about 26 million amps.

That little ball starts collapsing
at a million miles an hour.

They're all united in a single quest.

So, it's about to get dangerous,
so we'd better take off.

It's the greatest engineering
challenge that we have yet faced -

to build a machine that
will make a star on Earth.

Sunrise, dawn. That moment
when night becomes day that had

an immense significance
for our ancestors.

The sun sets the rhythm
for life on Earth.

Each day it returns
and the world awakens.

I think in one way
we've lost that sense of

significance of the sunrise in
our modern, electrically-lit world.



But, in another way,
that's been replaced

by modern science's understanding

of the sun as a violent,
majestic and massive object.

And...as is often the way when
you understand the true nature

of something, then that's all
the more reason to revere it.

The sun bathes our planet in energy.

It's so powerful that in
just one second its light

could supply the United States
with energy for a million years.

And hidden at its heart
is the power source -

all 385 million, million,
million, million watts of it.

It's a power source that lights up

every one of the 100
billion stars in our galaxy.

So the universe is awash

with effectively limitless
amounts of energy.

Then you have to ask the question,
is there a way of producing

the energy that you need to run
all this for everyone in the world,

in a way that doesn't damage the planet?

As a physicist, there is a way.
In principle, there's a way.

It's the same way that stars
produce energy. It's nuclear fusion.

Nuclear fusion is nature's
power source, a process that has

kept our sun burning without fail
for five billion years and counting.

The question I want to ask in this
film is, is it possible that fusion

is a power source for the future?

Can a nuclear fusion power station
be constructed? And can we do it

sufficiently quickly that
we can use it to address

the pressing and serious energy
crisis that we've got today?

It sounds like science fiction.

But in the heart of Oxfordshire,
they've been busy lighting

little stars for over 30 years.

- So, what's the advantage of fusion?
- Well, the chief advantage of fusion

is probably it doesn't produce carbon
dioxide, so no global warming gasses.

'The Joint European Taurus, or JET,

'is the world's largest experimental
fusion reactor where each day

'they initiate this beautifully
simple nuclear reaction.'

So it seems to me that, in principle,

we have the ideal energy source.

It couldn't be better, could it?

It had one downside,
that it's very hard to do.

You had to create the conditions
that are 10 times hotter than

- the centre of the sun to initiate these reactions.
- HAD, you said?

But, right, we've done it -

in the machine that
you're about to look at.

Seven, six, five, four, three, two, one.

There it goes.

'Scientists have learned how
to create and hold star matter,

'a cocktail of gasses heated
to 100 million degrees.

'For a moment, a little piece of
the sun springs into life on earth.'

It's amazing. So we're
looking at the conditions,

ten times the conditions that are
present in the centre of the sun?

They're ten times the
temperature of the sun?

- Absolutely. - In that
reactor? - It's incredible

and it goes on for all those
seconds, you know, it's impressive.

The remarkable thing
is it seems routine.

I'm sure there's a lot of work
gone into making it routine.

- Yeah. - That's my sense of this.
- As people have got used to it.

Of course, there are times when we
actually put the real fuel in there

and a shot like that will be
producing lots of fusion power.

Very exciting, when that happened.

To this day, JET holds the
world record for fusion power.

Yet, despite decades of research
and this fleeting glimpse of fusion,

no electricity will ever
make it from here to the grid.

Learning how to produce
useful power from fusion

remains beyond our capabilities.

One thing we do know is that, in nature,

fusion only occurs in one place -

right in the centre of stars.

Vast celestial power
houses, like our sun.

The road to understanding
the sun has been long.

And it all began with a
remarkable piece of deduction.

So, how could you begin to
find out what the sun's made of?

I mean, you can't go there.

It's a long long way away and
it'd be a bit hot when you arrived.

Well, actually, the story
began back in the 1660s

with the British physicist Isaac Newton.

He used one of these, a prism,
to look at the light from the sun.

What Newton found is that if
you look at light through a prism

then it splits up into its component
colours. It makes a rainbow.

Now, at the time, Newton didn't
appreciate the full significance

of his discovery, or at
least the usefulness of it.

Through the 18th and 19th
centuries, chemists and physicists

looked at the light in real detail.

And what they noticed was that
the spectrum isn't continuous.

It has pieces missing, it
has black lines through it.

This was a puzzle. Why was
some of the sun's light missing?

The answer is beautifully simple.

Each chemical element
in the sun absorbs light

to produce its own unique
pattern of black lines,

known as absorption lines,
in the solar spectrum.

A kind of fingerprint for
every element in the universe.

That leaves you with an
interesting possibility.

If you look at the light
from the sun and you look

where the black lines are,

then you can deduce exactly what
elements are present in the sun.

And today, from many precision
observations of the light

from the sun, using just this technique,

we know that the sun is 75% hydrogen,

24% helium and about 1% the heavier
elements that make up the universe.

Scientists had discovered what
the sun and stars were made of.

But they were no closer to
figuring out how something

made of the two lightest
elements in the universe -

hydrogen and helium
- could emit such vast quantities of energy.

Progress came with
the discovery of one of

the most famous equations in science.

Now, it took until 1905 and Einstein

for the key to the sun's
energy source to be revealed.

The equation E=MC2.

Energy equals mass times
the speed of light squared.

Speed of light squared, immense number.

It's got 16 noughts after it.

This huge number means

that only a small amount of mass
contains vast amounts of energy.

Einstein had uncovered a
remarkable facet of nature.

Mass is just an incredibly
condensed form of energy.

Imagine I took a dollar bill,

that's about a gram, and
converted that into pure energy.

That is the mass lost
in a hydrogen bomb.

So there's one hydrogen bomb's
worth of energy in every dollar bill.

When Einstein first wrote down
his famous equation, E=MC2,

it wasn't realised at
first that that was the key

to understanding the power of the sun.

It took another 15 years or so

for the British scientist,
Arthur Eddington, to...

well, what seems like
put two and two together.

But that would be
disrespectful to Eddington.

He noticed a result that had
again been known for many years.

That if you take four hydrogen nuclei,

like these rocks,

and you can stick them together
to make one thing, to make helium.

And it was known that
the helium weighed less.

It was less massive than the
four hydrogen nuclei on their own.

Eddington suggested that the
sun shines by combining hydrogen

into helium, releasing
the missing mass as energy.

And in fact we now
know that the sun loses

about 4 million tons of
mass every second as energy.

Now, of course it wasn't clear at
the time that Eddington was correct.

But correct he turned out to be.

What he'd actually discovered was
the process that came to be known

as nuclear fusion.

When Eddington had suggested
that fusion might be the process

that powers the sun, it was
pointed out to him that actually

the centre of the sun was not
hot enough for fusion to happen,

as physicists understood
the process at that time.

What you actually need is an
understanding of quantum mechanics

and that didn't come until later.

But Eddington was so sure of himself

that he said, "To those who suggest
that the centre of a star is not hot

"enough for fusion to take place,
I say go and find a hotter place."

Which is a very polite, British
way of saying, "Go to hell."

Of course, no hotter place was found

and Eddington's model for solar
fusion was adopted and refined.

But it left a big question -

how on earth do you light
a star in the first place?

A drive-in movie theatre.

Last time I saw one
of these was in Grease

with John Travolta
and Olivia Newton-John.

To find an answer, I've arranged
to meet a Californian astronomer

called Alex Filippenko who's going
to take me back 13.5 billion years

to a time before the stars ever existed.

Remarkably, astronomers have
been able to collect light from

this time, just 380,000 years after
the universe began at the Big Bang.

Oh, wow. Here we're
seeing the launch of WMAP.

'A satellite called WMAP

'was able to take a snapshot
of the universe in its infancy.'

The different colours,
what do they represent?

Yeah. The reds and blues

signify slightly hotter than average
and cooler than average regions.

And those correspond with
slight differences in density.

'In the denser regions, the primeval
constituents of the universe were

'drawn together by gravity.'

So the universe was, at
the time of the WMAP image,

- was hydrogen, helium?
- Hydrogen and helium, that's it.

Because during the Big Bang
temperatures and pressures

weren't high enough for very long
to produce the heavier elements.

'Over time the regions of hot, dense
hydrogen and helium clumped together

'to create huge stellar nurseries
- ideal places for stars to form.'

These slight little
variations in the density

led to regions that started
collapsing, clouds of gas

that started collapsing to form
clusters of galaxies and galaxies.

And then, within them,
stars could form as well.

'The first generation of stars lit up,

'initiating fusion and bringing
an end to the universe's Dark Age.'

That would be a star there,
would it, beginning to form?

Yeah, that's right. You're seeing
clumps of hydrogen and helium

and then gravity, the great
sculptor of the universe,

causes these things to collapse,
forming stars like this one.

'Many of these first stars were giants,

'hundreds of times more
massive than the sun.'

'They burnt their hydrogen fuel quickly

'and died in supernova explosions.

'They were the early chemical
factories of the universe.

'From just hydrogen and helium in
the beginning, generations of stars

'have created every element
we're familiar with today.'

The stars are the fusion reactors

that produced the heavy
elements of which we are made.

I think it's a wonderful thought,
because I look at my hand and

that is... Well, it's red because
there is iron in it and it's made

- of carbon and oxygen and that stuff.
- You're made of star stuff.

Quite literally the heavy
elements in your body -

anything other than hydrogen and helium

was produced inside of
stars billions of years ago.

We really are children of the stars,

created by the simplest of nuclear reactions
- fusion.

And now that we understand
this remarkable process

it offers us a tantalizing prospect.

If we could reproduce the
energy generating process

at the heart of the sun, if
we could build a star on Earth,

then our energy generation
problems would be over for ever.

For now, though, we continue to
rely almost entirely on our sun.

I suppose in a way our
civilization runs off batteries.

Over billions of years the
sunlight has been captured

by stuff like this.
Then it's decayed away.

And in places like this,
on the San Andreas Fault,

the geological conditions
are just right to cook this

into oil that we can then
pump out of the ground and burn

and take that condensed sunlight
and use it to power our civilization.

The energy from fossil fuels
like coal, gas and the oil here

in California have provided the
power that built the modern world.

All of it the result of biology and

chemistry made possible thanks to
the great fusion reactor in the sky.

We thought we'd got lucky.

We'd found a seemingly
endless supply of energy.

Here in the heart of oil country,
I hooked up with physicist

Rich Muller to chew over our
dependence on the black stuff.

I love this.

What is our love affair
with this substance, oil?

Well, you know, I don't think of it

so much as a love affair as a marriage.

And a somewhat unhappy marriage.

And we seek a divorce but the
divorce is going to be expensive.

It really is a very
remarkable substance.

It has enormous energy, enormous energy.

So much more than even TNT or dynamite.

It doesn't leave behind any residue.

Unlike coal, you don't have to
clear the ashes out of your car.

All it does it is spew off this,
what we used to call harmless gas,

carbon dioxide, into the atmosphere.

In terms of energy, it's got more
energy than TNT and natural gas.

More energy than these shotgun shells

by a factor of almost a thousand.

The incredible energy density
of oil is part of the reason

why fusion is not yet here.

It's not simply that making
the star is too difficult.

It's also that we haven't had to

because the sun has
given us the black gold.

It's such a wonderful thing.

Only problem is...
one, we're short of it.

And so it leads to war in the Mid-East.

And the second problem is,
it does put out carbon dioxide

and that very likely
leads to global warming.

GUNSHOT

This is my new sport, man. I like this.

Most of us on this planet, as we sit
in our air-conditioned hotel rooms

or at home watching TV, are
still burning fossil fuels.

As a result, the carbon
dioxide we are releasing

continues to warm the planet.

Quite how this will change our world,

and what this means for our
civilisation, no one yet knows.

But what's strange is even though
we do know our demand for energy

is unbalancing the climate,
the world cannot agree

on how our species
should power the homes,

factories and farms of the future.

In search of an answer
I've come to San Francisco,

to the headquarters of a
wind power research company,

to meet its chief engineer.

I met Saul Griffith about a year
ago, and I wanted to talk to him

in this film because he's
one of the few people I've met

that takes the emotion
out of the energy debate.

He just speaks in raw facts and figures.

And he's got an office in a control
tower on a disused military base

which is...

Here we are on this finite

little bowl that's spinning
through the universe.

There is a limit to how much
power per square metre we can get.

We shouldn't be afraid of that limit,

but we should certainly
try to operate within it.

Let's as quickly as possible

get the debate about energy away from
emotional and qualitative and polar bear issues,

and to a very rational,

"what do we have to do,
how do we get this done?"

Saul's response was to begin at home.

He wanted to understand
exactly how much energy he uses.

I'm a bicycle commuter,

I use public transport, I
run a wind energy company.

I should be a good human, right?

But I didn't actually know,
numerically, if I was good.

So I counted up all the
energy my lifestyle uses.

I can tell you the
amount of power it takes

to have the New York Times delivered,

how much power it takes
to have a hot shower.

I know how much power I
use flying around the place

to talk to people like you.

I know how much power I use
driving. And I was a little shocked.

I actually use more than
the average American.

So I am right now a hypocrite.
Here I am talking to you

about all of this,

but I'm using way more
than the average US person.

That means that this halo
of light behind me you see

is not actually genius.

That's the 300 light bulbs
that are burning constantly

24 hours a day, seven days a week.

That's how much power my lifestyle uses.

The average American
uses 11.4 kilowatts.

The global average is 2.2 kilowatts.

Which means the world's
total energy consumption

is currently around 13 terawatts,
or 13 million million watts.

To understand the scale of the
problem, I posed a question to Saul.

What would it take to share
the world's energy equally,

and give all six billion
of us five kilowatts each?

A global total of 30 terawatts.

And let's see if we can achieve
this, without fossil fuels, by 2035.

Let's shoot for this
morally pleasing level.

This one.

We'll call this the Brian Agenda.

Well, yeah, because the Brian Agenda
is to allow everybody on the Earth

to live a lifestyle
approximately like mine.

'In the west, we'd have to
get used to using a lot less.

'But in the developing world,

'this extra energy could provide
roads and schools and hospitals,

'everything we take for granted.'

So let's go with that. It's
hugely optimistic, but let's do it.

Let's go to five kilowatts.

'The next step is to figure
out just how much clean energy

'that is for the entire world.'

Thirty terawatts of energy

has to come from some new
clean source or sources.

OK, 30 terawatts, 25 years.

I'm totally behind the Brian Agenda.

So, what are the implications
of my eponymous plan

to make the world a
more equitable place?

How about generating a sixth
of our power, five terawatts,

from conventional nuclear?

So we need 5,000 nuclear
reactors in 25 years.

That's two and a half full
size nuclear reactors every week

for the next 25 years.

Every three minutes you need to install

a full size three megawatt wind turbine.

That's gonna be a couple of percent
of the land area of the world

that has wind turbines on it.

Solar at 10 terawatts, 250 square
metres of solar cell every second -

second after second after second
after second for the next 25 years.

Biofuels, two terawatts.
This one looks a little scary.

That's something like
four Olympic swimming pools

full of genetically engineered bacteria,

every second for the next 25 years.

And so on.

It's becoming clear that freeing
ourselves of our fossil fuel addiction,

let alone creating a
more equitable world,

is gonna require a
massive global effort.

And we haven't even factored in
the inevitable population growth.

So, look, this is possible
to realise the Brian Agenda.

But it's a pretty radical programme.

This is like the re-tooling of
manufacture for World War II,

except Britain, Germany,
Japan and America

are playing on the same team.

And every week that passes by, when the world
fails to build these alternative sources,

means Saul's numbers just
keep on getting bigger.

Could fusion power help?

Unfortunately, right now for
nuclear fusion, it's a question mark.

We don't know whether it works.

But the sensible thing would
be to increase investment?

Certainly if we nail fusion,

that looks like the Get Out
Of Jail Free card for humanity.

The aspiration to raise everybody up
to a minimum standard of energy use,

that is comparable with
the energy use in the west,

is not beyond the realms of possibility.

But a global consensus

that we have to stop our destructive
use of fossil fuels, is emerging.

What I'm not clear about is whether
fusion is probably so far away

that it won't have an impact on the
first phase of the energy crisis,

the phase we're in now.

So do we need to focus
our investment efforts

on building more efficient power
stations, building solar and wind?

Or, if we are convinced
that fusion will work

and the technological
difficulties can be overcome

on a very short timescale,
then do we really go for it?

Do we say we're gonna spend
10 or 100 times more R&D money,

worldwide, on fusion now?

I believe we must at least
try as hard as we possibly can.

After all, we have already built a
star, but for wholly different ends.

During World War II,

a generation of the finest
scientific and engineering minds

were brought together
in the New Mexico desert

to work on the top
secret Manhattan Project.

This is it, the place where the
nuclear age began, the Trinity site,

where the world's first nuclear
bomb was exploded, July 16th 1945.

It's where the power of
the nucleus was unlocked.

In just five years,

they'd learned how to access
the power of the nucleus

by splitting nuclei apart.

They created a fission bomb.

They soon realised that they
could release even more energy

if they could fuse the
nuclei and the fuel together.

Thing is, the fuel
is positively charged.

And that means that as it comes
closer together, it repels away.

What you're fighting
is electro-magnetism.

But if the nuclei can be
brought close enough together,

against the repulsive
electro-magnetic force,

another force of nature,
the strong nuclear force,

will take over and bind
the nuclei together.

Fusion.

So what you need to do is get
these things moving fast enough

that they get close enough for the
strong nuclear force to kick in,

short range, to lock them together.

Now, getting things moving
fast is another way of saying

you need to make them hot.

That's what temperature is, the
measure of the speed of the fuel.

And the bomb builders had just the tool.

They would use the incredible temperatures
and densities of a fission bomb

to overcome the electromagnetic
force and achieve fusion.

NEWSREEL MUSIC

ORIGINAL ANNOUNCER: This
is the first full scale test

of a hydrogen device.

If the reaction goes, we're
in the thermo-nuclear era!

Just eight years after entering
the nuclear age at Trinity,

they were at the brink of lighting
the first ever star on Earth.'

SITE PA: Now 30 seconds to zero time.

Ivy Mike, as the test was known,

was the first full-scale attempt to
detonate a fusion or hydrogen bomb.

One of the scientists who witnessed
the birth of the nuclear age

is Sterling Colgate.

We can simulate what goes on in a star.

In... It isn't quite the
laboratory, but at the test range,

or some exquisitely beautiful
atoll that we blow all to shit,

if you don't mind the word.

Cos it's just ghastly
what all of that did!

And it's a lesson for the whole world.

Never, never, never
let that happen again.

Five, four, three, two, one, zero!

They had unleashed the most
powerful force in nature.

This happens in the stars,
it happens in our sun.

If it didn't, we wouldn't be here.

And so you can't turn the clock back.

You can't deny the physics.

It's there. What we have to do
is deny the use of a fusion bomb,

a hydrogen bomb as it's called,

in any anger whatsoever.

We absolutely have to make a
massive commitment as a culture

that this can never, never happen.

However we also need
to take that knowledge

and use it to generate power.

And make the power
that we need to go on.

Future lab is completely gone.

Nothing there but water and
what appears to be a deep crater.

Whatever you think about the power you
can extract from the atomic nucleus,

the simple fact, the scientific fact is,

there is no greater power
source in the universe.

It's the power source
that powers the sun,

it's the power source
that powers the stars

and it can be the power source
that powers our civilisation.

What's needed is a
Manhattan Project type effort

to unlock the immense energy
store of the atomic nucleus.

But this time for peaceful purposes.

Today, fusion scientists continue
to face the same challenge.

They must overcome the
electromagnetic force

by creating incredibly high
temperatures and pressures,

but in a much more controlled way.

Currently, the world spends only
£1 billion a year on the problem.

In the UK, we spent more
money on ringtones last year

than we contributed to
the global fusion efforts.

You've got to ask yourself
whether our civilization

has got its priorities right.

Much of fusion funding still
goes into bomb research.

But these days, the demolition
of South Pacific islands

is out of fashion.

Instead, the generals hire the
world's most powerful bomb simulator.

Well, welcome, Brian.
This is the Z Machine.

Located on a high security
base just outside Albuquerque,

the Z Machine, as it's
known, is run by John Porter.

So, this is the largest pulse
power device in the world.

It's also the largest X-ray
generator in the world.

So in about an hour we're going
to discharge about 26 million amps

through a little thimble-sized
cylinder of wires.

This is, you know, 100 times bigger

than the instantaneous power
consumption of the United States,

at least.

So, again, just phenomenal amounts.

But for very short periods of time.

With all this power at its disposal,

the Z Machine is able to recreate
the conditions inside an H bomb.

And so at this point, the
conductors are inside a vacuum.

And then they're converging all to the
axis and about, I dunno, 10 feet down there

is where all the current gets
concentrated in the thin wires.

Nearby, John shows me a target

that will sit at the
centre of the machine.

So the 26 million amps is
flowing right along there.

And then you can barely
see the array of wires.

There's probably like 300 wires here.

- They look like a spider's web.
- Exactly. - Absolutely tiny.

When it fires, these wires
are rapidly vaporised.

And the strong magnetic field generated
by the enormous electric currents

force the wire remnants to implode.

This is known as a Z-pinch.

And it's this that
creates the conditions

for nuclear fusion to occur.

The diagnosticians are
back down from re-arming

and we're gonna continue
with our check list.

The radiation generated
by this machine is extreme,

and it can, in certain places,
create lethal doses of radiation.

- So it's not a good idea to be stood here when you do that?
- That's right!

- So it's about to get dangerous, so we'd better take off!
- Right.

And we've got red flashing lights,

- all the signs that it's better to leave.
- Yeah. Very exciting.

So we do about one shot a day.

So this has already been locked up.
I'll take you to the control room.

The X-rays are so intense
that people and video cameras

are only safe inside the
specially-shielded control room.

- You guys ready? - We're ready for
you to arm. - OK, we're still armed.

Attention building 983,
Z is preparing to fire.

We are starting ZBL countdown.

We are counting, T-minus 135.

We are charging.

They're gonna take
it up to 82,000 volts.

We are charging the MTGs.

When it fires, this vast brute
of a machine is powerful enough

to create a minor Earthquake
that's felt across the entire site.

Charge complete, arming to fire.

T-zero...

- DISTANT BOOM -
Trigger! - Whoa!

Only one image of the blast
has ever been captured.

This is that image.

It's called a flash-over,

the result of the ferocious
electromagnetic pulse

as lightning dances around
the metals in the room.

Thanks, John.

Did you guys trigger? Cool.

That was it, it's a success.

I felt the ground move.

I think you did too, Brian?

Yeah. And heard it out there, actually!

All right, let's go look and
see what's left after the shot.

So this was all fairly pristine,
at one point, stainless steel.

It's quite remarkable.
It's almost like the...

Well, it is the conditions
in an atomic bomb, isn't it?

Well, that's the reason these
facilities were first created.

- So, that's why it looks like it's been in a nuclear war?
- Exactly!

- Cos it has!
- Right.

A relic of the Cold War, the
Z Machine is being re-invented.

It turns out that this bomb simulator

could perhaps be turned into a
peaceful source of fusion energy.

It costs a few tens of
thousands of dollars to machine.

All the parts we just blew up
in a few billionths of a second.

The big hurdle is doing
it a few times a second

or a few times a minute,
depending on the yields,

to get enough power to be useful.

- Then you've got a power station.
- Exactly. It's the last few feet,

the stuff that gets blown up.

Coming up with new ideas on
how to rapidly replace that.

Currently it takes at
least a full working day

to prepare the Z
Machine for another shot.

But if they can learn how to replace all the
hardware that gets destroyed quickly enough,

in less than a minute,

then it's possible that
a machine similar to this

could one day produce a
steady stream of energy.

But it's a tall order.

We believe this technology that
you're seeing here is the simplest,

most elegant and efficient technology

that one could imagine to create fusion.

But no one knows, you know,
what's really possible. Right?

The Z Machine proves it
is experimentally possible

to light a star on Earth by
initiating a controlled explosion

around a fusion fuel.

So it does recreate the
conditions that are present

at the heart of a star.

It's also produced fusion.

But most of all it's simple.

That is the most impressive
thing to me. It was, or it is,

in a way, 19th century technology.

And that's not to denigrate
the machine at all.

It's a very simple idea.

And I suppose if you want
to build a power station,

if you really want technology you
can produce on an industrial scale,

then you want to do it in
as simple a way as possible.

And that's because the
scientists are facing

perhaps the most difficult
engineering challenge in history.

To produce a viable power plant,
they must engineer machines

that can not only create and withstand
the violent conditions found in stars,

but that are capable of creating
hundreds of these exploding stars,

every minute.

Only then will they be able to
extract a steady supply of energy

and create significant amounts
of electricity for the grid.

No wonder fusion power is
taking so long to come online,

even though we've understood this
process at the sub-atomic level

for well over half a century.

This is how fusion works in the sun.

You start off with protons.

Nuclei of hydrogen.

And if those protons can
get close enough together,

so the strong nuclear force, short
range force can lock them together,

then one of those protons
can turn into a neutron.

And two particles called
the positron and neutrino

come flying out.

And that makes an isotope of hydrogen,

something called deuterium.

And about a 7,000th of
the hydrogen in your water

is actually deuterium.

So it's pretty common on Earth.

That process takes a long, long time.

In fact, for a single proton in the sun,

then it would have to
wait billions of years

to get close enough to
undergo that process.

So that's the blockage in
fusion in the sun, if you like.

Once that's happened and
the deuterium's formed,

then everything goes very quickly.

Another proton can come
and meet the deuterium

and that turns the
deuterium into helium-3.

And actually a photon particle
of light comes flying out.

And then two of these helium-3s
can stick together into helium-4,

and a couple of protons come flying out.

So that's the process by which
energy is released in the sun.

It's the process that
allows the sun to shine.

On Earth though, we have an advantage.

We don't have to go through the
lengthy process of making deuterium

because the oceans are full of it.

A rich seam of energy that
could supply the entire world

for millions of years.

It's this tantalising promise
of effectively unlimited energy

that has inspired another approach
designed to initiate fusion.

At the Lawrence Livermore
National Laboratory in California,

they're attempting to create
a stream of exploding stars

using nothing more than a light beam.

Wow!

The governor yesterday, and me today!

VIDEO NARRATOR: The
National Ignition Facility

will do what has never
before been accomplished.

To create a self-sustained
nuclear fusion reaction

in a safe, controlled setting.

At the National Ignition
Facility, or NIF,

they've built the world's
largest and most powerful laser.

Showing me around this enormous
site is fusion scientist Eric Storm.

- Is that the laser?
- Yeah, stop a second. It looks like a factory.

The 500 trillion watt laser
beam travels half a kilometre,

guided by a series
of lenses and mirrors,

a pulse of light with a thousand times
the instantaneous amount of energy

in America's national grid.

This shows the actual size
of one of these laser beams.

They all come from one single source

and at the end get focused
onto this fusion target.

TWO-WAY RADIO: We're trying to
get hold of Sopado or Seranowski.

Copy.

OK.

- You can see it is somewhat more impressive.
- It's incredible.

You know, this looks like a
facility that creates stars.

It does, doesn't it? It looks
like it does what it says it does.

These aluminium square tubes here,

that's where the laser beams come in.

There are 96 beams on the
top and 96 on the bottom.

There are focusing lenses
that take these beams

and focus them down to a human hair.

That would give you quite
a suntan, wouldn't it?

Yeah, you would?!

I do not recommend it.

Let's go and look inside the chamber.

INDISTINCT VOICE ON RADIO

- Right, you're looking inside the star chamber.
- Look at that.

INDISTINCT VOICE ON RADIO

- The target will be sitting... You can see the...
- It's moving in.

That's the one that will hold the
target in the centre of the chamber.

- Which is the seed of the star.
- The seed of the star, absolutely.

BELL RINGS

'The man in charge of the
most powerful laser on Earth

'is Ed Moses.'

I want to talk about the
target because this is the...

First, how much energy do you
get out of one of those targets?

It's an interesting question.
This target is pretty small.

That little ball is where
the fuel for this target is.

Cos this is where the
challenge is, right?

The design of this thing.

There's a lot of challenges. You
have to put the laser together,

- you have to get all those lasers...
- You've done that, though. - Yeah.

We have to get those 192 beams steered
very precisely into this target.

The laser light is
coming down and up on it

in a very symmetrical fashion
so we make a very uniform oven.

That little ball starts collapsing
at a million miles an hour.

When it starts moving,

the hydrodynamic forces
on it are such that

it could start ripping itself apart.

So you have to make it come
together really nicely and smoothly

till it's about the
diameter of your hair.

When you do, you'll have temperatures

of around 100 million degrees

and pressures of around
100 billion atmospheres.

It'll be about a hundred
times as dense as lead

and that's when it will light
up and this is not chemical burn.

This is nuclear burn,
that's what's so interesting.

You get around 30 million
times more energy per mass

out of a nuclear burning device
than a chemical burning device.

But no laser-powered fusion
device has yet to achieve this.

So far, it's proved difficult
to focus all the power

onto the target at
precisely the same time.

Only if this can be overcome
will the fuel target be heated

and condensed enough
for fusion to occur.

This is the Holy Grail
- the quest for ignition.

So you had this star that's
about the diameter of a human hair

for a billionth of a second.

Yeah, it's star power on
Earth. That's what we say.

If we can do it a few times a second

then you get the kind of energy
that comes out of a power plant.

NIF is not a power plant,

but this vast experiment may be
on the brink of igniting a star.

It is our future.

When is that future going to arrive?

What would you say? I know
it's difficult to speculate,

but 10 years, 20 years, 50 years?

I think from the point of view of
proving fusion in this laboratory,

our goal is to do that in
the next two or three years.

Sometimes, people talk about
fusion as being 50 years away.

Right now, I look at it
as two or three years away.

By 2011, the world should know whether
laser-powered fusion will achieve ignition.

Should they fail, then all
humanity's hopes for fusion

will shift to another
group of scientists.

These researchers believe
our future energy will come,

not from a stream of
short-lived mini stars,

but from learning how to
create and hold the very matter

of the sun for days and months on end.

They too face a tremendous challenge

for they seek to control the least
well understood state of matter -

plasma.

If you heat up any atoms or molecules,

what happens very quickly is that
the electrons around the nucleus

start to boil off.

The temperature's too high for them
to stick in orbit around the nucleus

and that is the state
of most of the universe,

including the state of our nearby star,

that incredibly hot ball of plasma
- the sun.

Producing long-lived plasmas

is the oldest line of
fusion power research.

For 50 years, a small group of countries
have run prototype fusion reactors

in an attempt to extract
energy from stable plasma.

The very latest country
to join this club

is South Korea.

Here we are
- the National Fusion Research Centre.

Strange thing as well, it's in
the middle of an industrial estate.

When you think of a nuclear reactor facility,
you tend to think of it out in a field somewhere,

but it's right in the
middle of the city.

- Good morning, how are you?
- Good to see you.

- OK, I'll show you the KSTAR.
- Thank you.

'KSTAR, like the jet
reactor in Oxfordshire,

'is a type of fusion
reactor called a tokamak.'

- It's a beautiful device.
- Ah-ha. - It's clean.

'It was completed in late 2007

'and I've been invited to see the device
before it begins operation later this year

'by its chief creator, Dr Lee.'

He used to be a vacuum engineer.

- Thank you.
- You can go.

Bye.

Thanks.

'What makes KSTAR unique are the
advanced super-conducting magnets

'that hold the plasma in place.

'They cool to minus 269 degrees.

'At this temperature,

'the magnets have no
electrical resistance,

'which means KSTAR needs a lot less
power to run than its predecessors.'

What's the thing you hope
to learn with this machine?

So far, all the tokamak fusion reactor

runs for a very short period of time.

A few seconds.

So we, scientifically, we have
proven fusion can be realisable.

- Yeah.
- But on the other hand, we have to make energy

- so this machine has to run a long way, you know?
- Mmm.

Eventually, nine months
and ten months continuously.

So, you would contain the plasma?

- Yeah.
- What, months at a time?

Yes.

'KSTAR aims to show that plasma
can be routinely created and held

'for long periods deep within
the heart of the machine

'in the way needed for a
commercial fusion power station.'

This is a very exciting
moment, actually.

I never imagined I'd get to climb
inside the reactor, which is...

unbelievable.

It's not easy access!

How did he do that?

HE LAUGHS

Oof!

This is brilliant, I've got to say.

Well, this is the inside of KSTAR.

When this is operating, where my
head is, there will be a plasma,

10, 20 times hotter
than the core of the sun.

And it works, basically,
like a home microwave oven,

except that six megawatts
is the power consumption of

2,000 domestic houses. So...

it's a remarkable place.

The temperature here, 20 times
hotter than the centre of the sun.

Below my feet, where the
magnets are, minus 269 degrees,

which is something like the temperature,
if you go outside the Earth's atmosphere,

and outside, actually, to the most
distant planets, incredibly cold.

And this is one of the
best bits, in a way,

it's the television camera.

And they've already had some success.

Just before my visit,

they ran the machine for the first time.

It's not fusion yet,

but an important step
towards KSTAR's goal

of holding 100,000 degree
plasma for five minutes.

If they can achieve this,

it will be a significant landmark
on the road to fusion power.

Will you get net energy out of KSTAR?

KSTAR will be...

kind of break even machine.

So, energy consumption to
really support the whole system,

and the energy out is almost,
you know, one to one, like.

But an economical power plant,

we are now considering, is about
30 to 50 times of this is necessary.

Means one watt comes in,

and 30 to 50 comes out.

Then, we can really make it in

the reasonable cost of
electricity from the fusion device.

The South Koreans have built KSTAR

as their contribution to
an international project

to build the biggest fusion
reactor ever attempted, called ITER,

which is about to begin
construction in Southern France.

- Really, this is the start of the final phase of R&D towards fusion.
- I think so. Yes.

We have done 50 years of R&D in fusion,

fusing lots of machines, many places.

- Now, this is endgame.
- Yes.

So, now, put together all the
knowledge of these 50 years

and now, merging into this, KSTAR,
ITER, and finally, commercialisation.

This machine, having seen it, means
more to me than I thought it would

because I really get the sense
that if this doesn't work,

then, we're in, literally, real trouble.

Hopefully, it's all engineering,
and it's all practice.

It's not simple because
it will take decades.

But it's not a fundamental issue,

because if it were a fundamental issue,

then this kind of fusion
would drop out of the race,

and we'd be left with
one, with laser fusion.

And for me, if you think that fusion
is the future of our civilisation,

that's a big risk.

So, good luck, KSTAR.

If you'd asked me
before I made this film -

what are the greatest achievements
in the history of humanity?,

I would say, the moments
when we overreach,

the moments when we
set foot on the moon,

or took photographs of Saturn
and Jupiter and distant planets.

Building a fusion
power station that works

and delivers electrons into
the power grid of a city

will be the next step

in the evolution of our civilisation.

It's just about beyond our capabilities,

technologically and
scientifically, at the moment.

And that's surely the best place to be.

That's the place you want
to stand, as a human being.

So, I would celebrate the
fusion power station builders

in a way that I wouldn't have
done before we made this film.

So, when can we expect
fusion power from the mains?

All right. My prediction.
I hate being a futurist.

♪ This time tomorrow,
where will we be?... ♪

2036, June.

That's when it COULD be done

with an exerted effort.

2027.

I don't think it will happen until then.

♪ This time tomorrow

♪ What will we know...? ♪

There's a 50% chance of it working,

20 years after you
seriously fund the science.

So, it's time for a commitment.

♪ I'll leave the sun behind me

♪ And I'll watch the clouds
as they sadly pass me by

♪ Seven miles below me

♪ I can see the world
and it ain't so big at all

♪ This time tomorrow

♪ What will we see...? ♪

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