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At the dawn of the 19th century,

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in a cellar in Mayfair,

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the most famous scientist
of the time, Humphry Davy,

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built an extraordinary piece
of electrical equipment.

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Four metres wide, twice as long

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and containing stinking stacks
of acid and metal,

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it had been created to pump out
more electricity

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than had ever been possible before.

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It was in fact the biggest battery

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the world had ever seen.

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With it, Davy was about to propel us

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into a new age.

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That moment would take place at
a lecture at the Royal Institution,

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in front of hundreds
of London's great and good.

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Filled with anticipation,
they packed the seats,

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hoping to witness a new
and exciting electrical wonder.

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But what they would see that night
would be something truly unique.

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Something they would remember
for the rest of their lives.

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Using just two simple carbon rods,

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Humphry Davy was about to unleash
the true potential of electricity.

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Electricity is one of nature's
most awesome phenomena,

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and the most powerful manifestation
of it we ever see

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is lightning.

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This is the story of how
we first dreamed of controlling

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this primal force of nature,

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and how we would ultimately
become its master.

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It's a 300-year tale

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of dazzling leaps of imagination
and extraordinary experiments.

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Tens of thousands of volts
passed across his body

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and through the end of a lamp
that he was holding.

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It's a story of a maverick geniuses

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who used electricity
to light our cities,

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to communicate across the seas
and through the air,

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to create modern industry and
to give us the digital revolution.

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But in this film, we'll tell the
story of the very first scientists

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who started to unlock
the mysteries of electricity.

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It's as though
there's something alive in there.

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They studied
its curious link to life,

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built strange and powerful
instruments to create it

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and even tamed lightning itself.

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It was these men who truly laid
the foundations of the modern world.

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And it all started with a spark.

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Imagine our world
without electricity.

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It would be dark,

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cold and quiet.

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In many ways, it would be like
the beginning of the 18th century,

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where our story begins.

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This is the Royal Society in London.

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In the early 1700s,
after years in the wilderness,

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Isaac Newton
finally took control of it

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after the death of his arch-enemy,
Robert Hooke.

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Newton brought in his own people
to the key jobs,

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to help shore up his new position.

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The new head of demonstrations there
was 35-year-old Francis Hauksbee.

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Notes from the Royal Society in 1705

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reveal how hard Hauksbee tried

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to stamp his personality
on its weekly meetings,

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producing ever more spectacular
experiments to impress his masters.

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In November, he came up with this -

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a rotating glass sphere.

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He was able to remove the air
from inside it using a new machine -

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the air pump.

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On his machine, a handle allowed him
to spin the sphere.

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One by one,
the candles in the room were put out

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and Francis placed his hand
against the sphere.

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The audience were about to see
something amazing.

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'Inside the glass sphere,

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'a strange ethereal light
began to form,

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'dancing around his hand.

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'A light
no-one had ever seen before.'

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That's fantastic.

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You see a beautiful blue glow,
it's just marking out

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the shape of my hands,
but then going right round the ball.

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It's as though
there's something alive in there.

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It's difficult to really understand

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why this dancing blue light
meant so much,

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but we have to bear in mind
that at the time,

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natural phenomena like this were
seen to be the work of the Almighty.

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This was still a period when,
even in Isaac Newton's theory,

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God was constantly intervening
in the conduct of the world.

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It made sense for a lot of people

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to interpret natural phenomena
as acts of God.

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So when a mere mortal
meddled with God's work,

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it was almost beyond
rational comprehension.

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Hauksbee never realised the full
significance of his experiment.

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He lost interest
in his glowing sphere

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and spent the last few years
of his life

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building ever more
spectacular experiments

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for Isaac Newton
to test his other theories.

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He never realised
that he had unwittingly started

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an electrical revolution.

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Before Hauksbee, electricity
had been merely a curiosity.

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The ancient Greeks rubbed amber,
which they called electron,

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to get small shocks.

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Even Queen Elizabeth I marvelled

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at static electricity's power
to lift feathers.

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But now Hauksbee's machine

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could make electricity
at the turn of a handle,

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and you could see it.

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Perhaps even more importantly,
his invention coincided

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with the birth of a new movement
sweeping across Europe

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called the Enlightenment.

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Enlightened intellectuals
used reason to question the world

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and their legacy
was radical politics,

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iconoclastic art

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and natural philosophy, or science.

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But ironically,
Hauksbee's new machine

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wasn't immediately embraced
by most of these intellectuals.

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But instead,
by conjurers and street magicians.

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Those with an interest
in electricity

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called themselves electricians.

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One story tells of a dinner party
attended by an Austrian Count.

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The electrician had placed
some feathers on the table

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and then charged up a glass rod
with a silk handkerchief.

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He then astonished the guests
by lifting up the feathers

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with the rod.

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He then went on to charge himself up

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using one of Hauksbee's
electrical machines.

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He gave the guests electric shocks,
presumably to squeals of delight.

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But for his piece de resistance,

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he placed a glass of cognac
in the centre of the table,

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charged himself up again

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and lit it with a spark
from the tip of his finger.

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There was a trick called
the electrical beatification,

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in which the victim sits
on an insulated chair

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and above his head
hangs a metal crown

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that doesn't quite touch his head.

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And then if the crown
is electrified,

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then you get an electric discharge
around the crown

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that looks exactly like a halo,

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which is why it's called
the electric beatification.

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As England and the rest of Europe
went electricity crazy,

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the spectacles grew bigger.

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The more curious electricians

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started to ask
more profound questions,

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not only how can we make
our shows bigger and better,

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but how can we control
this amazing power?

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And for some, can this incredible
electrical fire

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do more than just entertain?

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One of the first early breakthroughs
would never have happened

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had it not been
for a terrible accident.

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This is Charterhouse
in the centre of London.

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Over the past 400 years,
it's been a charitable home

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for young orphans
and elderly gentleman.

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And sometime in the 1720s, it also
became home to one Stephen Gray.

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Stephen Gray had been a successful
silk dyer from Canterbury.

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He was used to seeing
electric sparks leap from the silk

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and they fascinated him.

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Unfortunately, a crippling accident
ended his career

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and left him destitute.

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But then he was offered
a new life here at Charterhouse

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and with it the time to perform
his own electrical experiments.

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Here at Charterhouse, possibly in
this very room, the Great Chamber,

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Stephen Gray built a wooden frame

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and from the top beam he suspended
two swings using silk rope.

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He also had a device like this,
a Hauksbee machine

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for generating static electricity.

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Now, with a large audience
in attendance,

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he got one of the orphan boys
who lived here at Charterhouse

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to lie across the two swings.

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Gray placed some gold leaf
in front of him.

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He then generated electricity

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and charged the boy
through a connecting rod.

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Gold leaf, even feathers,
leapt to the boy's fingers.

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Some of the audience
claimed they could even see sparks

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flying out from his fingertips.
Show business indeed.

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But to the curious
and inquiring mind of Stephen Gray,

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this said something else as well -

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electricity could move,

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from the machine to the boy's body,
through to his hands.

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But the silk rope stopped it dead.

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It meant the mysterious
electrical fluid

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could flow through some things...

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..but not through others.

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It led Gray to divide the world into
two different kinds of substances.

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He called them
insulators and conductors.

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Insulators held
electric charge within them

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and wouldn't let it move,
like the silk or hair,

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glass and resin.

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Whereas conductors allowed
electricity to flow through them,

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like the boy or metals.

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It's a distinction
which is still crucial even today.

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Just think of these electric pylons.

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They work on the same principle
that Gray deduced

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nearly 300 years ago.

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The wires are conductors.

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The glass and ceramic objects

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between the wire and the metal
of the pylon are insulators

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that stop the electricity
leaking from the wires

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into the pylon
and down to the earth.

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They're just like the silk ropes
in Gray's experiment.

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Back in the 1730s,

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Gray's experiment
may have astounded all who saw it,

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but it had a frustrating drawback.

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Try as he might, Gray
couldn't contain the electricity
he was generating for long.

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It leapt from the machine
to the boy and was quickly gone.

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The next step in our story came

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when we learnt
how to store electricity.

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But that would take place
not in Britain,

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but across the Channel
in mainland Europe.

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Across the Channel,
electricians were just as busy

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as their British counterparts and
one centre for electrical research

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was here in Leiden, Holland.

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And it was here that a professor
came up with an invention

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that many still regard as the most
significant of the 18th century,

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one that in some form or another
can still be found

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in almost every
electrical device today.

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That professor
was Pieter van Musschenbroek.

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Unlike Hauksbee and Gray,

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Musschenbroek
was born into academia.

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But ironically enough,
his breakthrough

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came not because
of his rigorous science,

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but because
of a simple human mistake.

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He was trying to find a way
to store electrical charge,

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ready for his demonstrations.
And you can almost hear

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his train of thought
as he tries to figure this out.

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00:16:12,440 --> 00:16:16,640
If electricity is a fluid
that flows, a bit like water,

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then maybe you can store it in the
same way that you can store water.

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So Musschenbroek
went to his laboratory

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to try to make a device
to store electricity.

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00:16:31,920 --> 00:16:35,480
Musschenbroek started
to think literally.

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He took a glass jar
and poured in some water.

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He then placed inside it
a length of conducting wire...

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..which was connected at the top
to a Hauksbee electric machine.

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'Then he put the jar on an insulator
to help keep the charge in the jar.'

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He then tried to pour
the electricity into the jar

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produced by the machine via the wire

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down through into the water.

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'But whatever he tried, the charge
just wouldn't stay in the jar.

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'Then one day, by accident,

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'he forgot to put the jar
on the insulator,

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'but charged it instead
while it was still in his hand.'

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Finally, holding the jar
with one hand,

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he touched the top with the other

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and received
such a powerful electric shock,

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he was almost thrown to the ground.

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He writes, "It's a new
but terrible experiment

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"which I advise you never to try.
Nor would I, who've experienced it

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"and survived by the grace of God
do it again

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"for all the kingdom of France."

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So I'm going to heed his advice,
not touch the top,

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and instead see if I can get
a spark off of it.

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The sheer power of the electricity
which flew from the jar

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was greater than any seen before.

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And even more surprisingly,

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the jar could store that electricity
for hours, even days.

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So in honour of the city where
Musschenbroek made his discovery,

248
00:18:35,560 --> 00:18:38,120
they called it the Leiden jar.

249
00:18:40,120 --> 00:18:44,000
And its fame
swept across the world.

250
00:18:44,000 --> 00:18:48,320
And very rapidly, from 1745
through the rest of the 1740s,

251
00:18:48,320 --> 00:18:52,720
the news of this - it's called
the Leiden jar - goes global.

252
00:18:52,720 --> 00:18:55,800
It spreads from Japan in East Asia

253
00:18:55,800 --> 00:18:59,240
to Philadelphia in eastern America.

254
00:18:59,240 --> 00:19:06,280
It became one of the first quick,
globalised, scientific news items.

255
00:19:08,200 --> 00:19:14,160
But although the Leiden jar became
a global electrical phenomenon,

256
00:19:14,160 --> 00:19:17,360
no-one had the slightest
idea how it worked.

257
00:19:18,480 --> 00:19:20,440
You have a jar of electric fluid,

258
00:19:20,440 --> 00:19:24,640
and it turns out that you get
a bigger shock from the jar

259
00:19:24,640 --> 00:19:29,480
if you allow the electric fluid
to drain away to the earth.

260
00:19:29,480 --> 00:19:33,960
Why is the shock bigger
if the jar's leaking?

261
00:19:33,960 --> 00:19:38,240
Why isn't the shock bigger if you
make sure all the electric fluid

262
00:19:38,240 --> 00:19:39,720
stays inside the jar?

263
00:19:39,720 --> 00:19:43,080
That was how mid-18th century
electrical philosophers

264
00:19:43,080 --> 00:19:45,080
were faced with this challenge.

265
00:19:49,160 --> 00:19:54,560
Electricity was without doubt
a fantastical wonder.

266
00:19:54,560 --> 00:19:56,880
It could shock and spark.

267
00:19:56,880 --> 00:19:59,560
It could now be stored
and moved around.

268
00:19:59,560 --> 00:20:03,240
Yet what electricity was,
how it worked,

269
00:20:03,240 --> 00:20:04,800
and why it did all these things

270
00:20:04,800 --> 00:20:09,440
was nothing less
than a complete mystery.

271
00:20:21,640 --> 00:20:25,320
Within 10 years,
a new breakthrough was to come

272
00:20:25,320 --> 00:20:28,120
from an unexpected quarter,

273
00:20:28,120 --> 00:20:31,840
From a man politically
and philosophically at war

274
00:20:31,840 --> 00:20:34,760
with the London establishment.

275
00:20:34,760 --> 00:20:38,600
And even more shockingly
for the British electrical elite,

276
00:20:38,600 --> 00:20:42,320
that man was merely a colonial.

277
00:20:42,320 --> 00:20:43,920
An American.

278
00:20:47,240 --> 00:20:49,360
This painting of Benjamin Franklin

279
00:20:49,360 --> 00:20:51,880
hangs here at the
Royal Society in London.

280
00:20:53,480 --> 00:20:57,960
Franklin was a passionate supporter
of American emancipation

281
00:20:57,960 --> 00:21:00,800
and saw the pursuit
of rational science,

282
00:21:00,800 --> 00:21:03,120
and particularly electricity,

283
00:21:03,120 --> 00:21:06,800
as a way of rolling back ignorance,
false idols

284
00:21:06,800 --> 00:21:13,080
and ultimately his intellectually
elitist colonial masters.

285
00:21:13,080 --> 00:21:19,000
And this is mixed with a profoundly
egalitarian democratic idea

286
00:21:19,000 --> 00:21:21,360
that Franklin and his allies have,

287
00:21:21,360 --> 00:21:25,000
which is this is
a phenomenon open to everyone.

288
00:21:25,000 --> 00:21:28,600
Here's something that the elite
doesn't really understand

289
00:21:28,600 --> 00:21:31,560
and we might be able
to understand it.

290
00:21:31,560 --> 00:21:34,720
Here's something that the elite
can't really control

291
00:21:34,720 --> 00:21:37,280
but we might be able to control.

292
00:21:37,280 --> 00:21:42,560
And here's something above all which
is the source of superstition.

293
00:21:42,560 --> 00:21:45,160
And we, rational, egalitarian,

294
00:21:45,160 --> 00:21:48,680
potentially democratic,
intellectuals,

295
00:21:48,680 --> 00:21:51,960
we will be able to reason it out,

296
00:21:51,960 --> 00:21:56,000
without appearing to be
the slaves of magic or mystery.

297
00:21:57,280 --> 00:22:01,200
So Franklin decided to use
the power of reason

298
00:22:01,200 --> 00:22:03,360
to rationally explain what many

299
00:22:03,360 --> 00:22:05,880
considered a magical phenomenon...

300
00:22:05,880 --> 00:22:07,120
Lightning.

301
00:22:07,120 --> 00:22:11,760
THUNDER BOOMS

302
00:22:11,760 --> 00:22:15,800
This is probably one of the most
famous scientific images

303
00:22:15,800 --> 00:22:17,280
of the 18th century.

304
00:22:17,280 --> 00:22:20,800
It shows Benjamin Franklin,
the heroic scientist,

305
00:22:20,800 --> 00:22:23,560
flying a kite in a storm,

306
00:22:23,560 --> 00:22:27,160
proving that lightning
is electrical.

307
00:22:27,160 --> 00:22:31,200
But although Franklin
proposed this experiment,

308
00:22:31,200 --> 00:22:33,640
he almost certainly
never performed it.

309
00:22:35,640 --> 00:22:39,920
Much more likely is that
his most significant experiment

310
00:22:39,920 --> 00:22:43,600
was another one which he proposed
but didn't even conduct.

311
00:22:43,600 --> 00:22:47,400
In fact, it didn't
even happen in America.

312
00:22:47,400 --> 00:22:50,320
It took place here in a small
village north of Paris

313
00:22:50,320 --> 00:22:52,160
called Marly La Ville.

314
00:22:55,320 --> 00:23:00,960
The French adored Franklin,
especially his
anti-British politics,

315
00:23:00,960 --> 00:23:03,680
and they took it upon themselves
to perform

316
00:23:03,680 --> 00:23:06,640
his other lightning
experiments without him.

317
00:23:07,640 --> 00:23:12,440
I've come to the very spot
where that experiment took place.

318
00:23:19,520 --> 00:23:23,160
In May 1752, George Louis Leclerc,

319
00:23:23,160 --> 00:23:27,000
known across France
as the Compte de Buffon,

320
00:23:27,000 --> 00:23:30,480
and his friend
Thomas Francois Dalibard,

321
00:23:30,480 --> 00:23:35,240
erected a 40-ft metal pole,
more than twice as high as this one,

322
00:23:35,240 --> 00:23:38,320
held in place
by three wooden staves,

323
00:23:38,320 --> 00:23:41,880
just outside Dalibard's house
here in the Marly La Ville.

324
00:23:41,880 --> 00:23:47,040
The metal pole rested at the bottom
inside an empty wine bottle.

325
00:23:50,840 --> 00:23:54,560
Franklin's big idea had been
that the long pole

326
00:23:54,560 --> 00:23:58,120
would capture the lightning,
pass it down the metal rod

327
00:23:58,120 --> 00:24:01,160
and store it in
the wine bottle at the base

328
00:24:01,160 --> 00:24:03,320
which worked as a Leiden jar.

329
00:24:03,320 --> 00:24:08,200
Then, he could confirm
what lightning actually was.

330
00:24:08,200 --> 00:24:12,120
All his French followers
had to do was wait for a storm.

331
00:24:17,040 --> 00:24:21,720
And then on May 23rd,
the heavens opened.

332
00:24:21,720 --> 00:24:23,880
THUNDER

333
00:24:23,880 --> 00:24:26,560
At 12.20, a loud
thunderclap was heard

334
00:24:26,560 --> 00:24:29,120
as lightning hit
the top of the pole.

335
00:24:31,080 --> 00:24:33,480
An assistant ran to the bottle,

336
00:24:33,480 --> 00:24:36,680
a spark leapt across

337
00:24:36,680 --> 00:24:39,240
between the metal and his finger
with a loud crack

338
00:24:39,240 --> 00:24:42,920
and a sulphurous smell,
burning his hand.

339
00:24:42,920 --> 00:24:47,600
The spark revealed lightning
for what it really was.

340
00:24:47,600 --> 00:24:51,880
It was the same as the electricity
made by man.

341
00:24:55,280 --> 00:24:58,920
It is hard to overestimate
the significance of this moment.

342
00:24:58,920 --> 00:25:03,480
Nature had been mastered, not only
that but the wrath of God itself

343
00:25:03,480 --> 00:25:06,920
had been brought
under the control of mankind.

344
00:25:06,920 --> 00:25:09,400
It was a kind of heresy.

345
00:25:09,400 --> 00:25:14,280
Franklin's experiment was very
important because it showed that

346
00:25:14,280 --> 00:25:18,920
lightning storms produce
or are produced by electricity

347
00:25:18,920 --> 00:25:22,880
and that you can bring
this electricity down,

348
00:25:22,880 --> 00:25:24,840
that electricity
is a force of nature

349
00:25:24,840 --> 00:25:26,920
that's waiting out there
to be tapped.

350
00:25:29,640 --> 00:25:34,640
Next, Franklin turned his rational
mind to another question.

351
00:25:34,640 --> 00:25:40,360
Why the Leiden jar made the biggest
sparks when it was held in the hand?

352
00:25:40,360 --> 00:25:44,520
Why didn't all the electricity
just drain away?

353
00:25:44,520 --> 00:25:49,320
In drawing on his experience
as a successful businessman,

354
00:25:49,320 --> 00:25:52,640
he saw something no-one else had.

355
00:25:52,640 --> 00:25:55,680
That like money in a bank,

356
00:25:55,680 --> 00:26:00,440
electricity can be in credit,
what he called positive,

357
00:26:00,440 --> 00:26:03,720
or debit, negative.

358
00:26:05,480 --> 00:26:09,520
For him, the problem of the Leiden
jar is one of accountancy.

359
00:26:09,520 --> 00:26:17,600
Franklin's idea was every body has
around an electrical atmosphere.

360
00:26:17,600 --> 00:26:22,600
And there is a natural amount
of electric fluid around each body.

361
00:26:22,600 --> 00:26:26,120
If there is too much,
we will call it positive.

362
00:26:26,120 --> 00:26:29,440
If there is too little,
we will call it negative.

363
00:26:29,440 --> 00:26:33,720
And nature is organised
so the positives and negatives

364
00:26:33,720 --> 00:26:35,920
always want to balance out,

365
00:26:35,920 --> 00:26:38,760
like an ideal American economy.

366
00:26:41,080 --> 00:26:46,200
Franklin's insight was that
electricity was actually just
positive charge

367
00:26:46,200 --> 00:26:50,120
flowing to cancel out
negative charge.

368
00:26:50,120 --> 00:26:52,880
And he believed this simple idea

369
00:26:52,880 --> 00:26:56,520
could solve the mystery
of the Leiden jar.

370
00:26:59,320 --> 00:27:01,480
As the jar is charged up,

371
00:27:01,480 --> 00:27:08,280
negative electrical charge is poured
down the wire and into the water.

372
00:27:08,280 --> 00:27:13,480
If the jar rests on an insulator,
a small amount builds up in the
water.

373
00:27:18,240 --> 00:27:23,120
But, if instead the jar is held by
someone as it is being charged,

374
00:27:23,120 --> 00:27:25,080
positive electric charge

375
00:27:25,080 --> 00:27:28,600
is sucked up through their
body from the ground

376
00:27:28,600 --> 00:27:30,400
to the outside of the jar,

377
00:27:30,400 --> 00:27:34,120
trying to cancel out
the negative charge inside.

378
00:27:36,160 --> 00:27:38,520
But the positive
and negative charges

379
00:27:38,520 --> 00:27:41,640
are stopped from cancelling out

380
00:27:41,640 --> 00:27:45,520
by the glass which
acts as an insulator.

381
00:27:45,520 --> 00:27:50,600
Instead, the charge just grows and
grows on both sides of the glass.

382
00:27:53,160 --> 00:27:56,760
Then, touching the top of the jar
with it the other hand,

383
00:27:56,760 --> 00:28:00,640
completes a circuit allowing
the negative charge on the inside

384
00:28:00,640 --> 00:28:05,520
to pass through the hand
to the positive on the outside,

385
00:28:05,520 --> 00:28:07,720
finally cancelling it out.

386
00:28:10,560 --> 00:28:16,400
The movement of this charge causes
a massive shock and often a spark.

387
00:28:22,120 --> 00:28:27,200
The modern equivalent of the Leiden
jar is this - the capacitor.

388
00:28:27,200 --> 00:28:30,920
It is one of the most
ubiquitous of electronic components.

389
00:28:30,920 --> 00:28:32,720
It is found everywhere.

390
00:28:32,720 --> 00:28:37,240
There are a number of smaller ones
scattered around on this circuit
board from a computer.

391
00:28:37,240 --> 00:28:40,800
They help smooth out
electrical surges,

392
00:28:40,800 --> 00:28:43,360
protecting sensitive components,

393
00:28:43,360 --> 00:28:46,400
even in the most modern
electric circuit.

394
00:28:57,000 --> 00:29:00,160
Solving the mystery
of the Leiden jar

395
00:29:00,160 --> 00:29:04,160
and recognising lightning as merely
a kind of electricity

396
00:29:04,160 --> 00:29:06,840
were two great successes
for Franklin

397
00:29:06,840 --> 00:29:09,440
and the new Enlightenment movement.

398
00:29:11,520 --> 00:29:14,400
But the forces of trade
and commerce,

399
00:29:14,400 --> 00:29:17,080
which helped fuel the Enlightenment,

400
00:29:17,080 --> 00:29:19,320
were about to throw up a new

401
00:29:19,320 --> 00:29:23,360
and even more perplexing
electrical mystery.

402
00:29:23,360 --> 00:29:26,920
A completely new
kind of electricity.

403
00:29:31,920 --> 00:29:33,920
This is the English Channel.

404
00:29:33,920 --> 00:29:36,000
By the 17th and 18th centuries,

405
00:29:36,000 --> 00:29:40,280
a good fraction of the world's
wealth flowed up this
stretch of water

406
00:29:40,280 --> 00:29:43,240
from all corners
of the British Empire

407
00:29:43,240 --> 00:29:45,680
and beyond, on its way to London.

408
00:29:45,680 --> 00:29:48,640
Spices from India,
sugar from the Caribbean,

409
00:29:48,640 --> 00:29:51,800
wheat from America, tea from China.

410
00:29:51,800 --> 00:29:54,640
But, of course,
it wasn't just commerce.

411
00:29:58,640 --> 00:30:00,840
New plants and animal specimens

412
00:30:00,840 --> 00:30:04,320
from all over the world
came flooding into London,

413
00:30:04,320 --> 00:30:08,680
including one that particularly
fascinated the electricians.

414
00:30:11,480 --> 00:30:16,720
Called the torpedo fish, it had been
the stuff of fishermen's tales.

415
00:30:16,720 --> 00:30:22,120
Its sting, it was said, was capable
of knocking a grown man down.

416
00:30:22,120 --> 00:30:26,040
But as the electricians started
to investigate the sting,

417
00:30:26,040 --> 00:30:30,160
they realised it felt strangely
similar to a shock

418
00:30:30,160 --> 00:30:31,680
from a Leiden jar.

419
00:30:34,240 --> 00:30:38,280
Could its sting actually
be an electric shock?

420
00:30:43,400 --> 00:30:48,160
At first, many people dismissed
the torpedo fish's shock as occult.

421
00:30:48,160 --> 00:30:51,760
Some said it was probably
just the fish biting.

422
00:30:51,760 --> 00:30:55,280
Others that it could not be a shock
because, without a spark,

423
00:30:55,280 --> 00:30:57,040
it just wasn't electricity.

424
00:30:57,040 --> 00:30:59,440
But, for most,
it was a very strange

425
00:30:59,440 --> 00:31:01,640
and inexplicable new mystery.

426
00:31:01,640 --> 00:31:03,320
It would take one of the oddest

427
00:31:03,320 --> 00:31:06,160
yet most brilliant
characters in British science

428
00:31:06,160 --> 00:31:09,520
to begin to unlock
the secrets of the torpedo fish.

429
00:31:14,760 --> 00:31:18,360
This is the only picture
in existence

430
00:31:18,360 --> 00:31:23,240
of the pathologically shy
but exceptional Henry Cavendish.

431
00:31:23,240 --> 00:31:27,960
This one only exists because
an artist sketched his coat

432
00:31:27,960 --> 00:31:32,040
as it hung on a peg, then filled
in the face from memory.

433
00:31:35,880 --> 00:31:38,320
His family were fantastically rich.

434
00:31:38,320 --> 00:31:40,120
They were the Devonshires

435
00:31:40,120 --> 00:31:44,640
who still own Chatsworth House
in Derbyshire.

436
00:31:44,640 --> 00:31:47,040
Henry Cavendish decided
to turn his back

437
00:31:47,040 --> 00:31:49,040
on his family's wealth and status

438
00:31:49,040 --> 00:31:53,160
to live in London
near his beloved Royal Society

439
00:31:53,160 --> 00:31:58,960
where he could quietly pursue his
passion for experimental science.

440
00:31:58,960 --> 00:32:04,080
When he heard about the electric
torpedo fish, he was intrigued.

441
00:32:04,080 --> 00:32:05,840
A friend wrote to him...

442
00:32:05,840 --> 00:32:10,240
"On this, my first experience
of the effect of the torpedo,

443
00:32:10,240 --> 00:32:14,640
"I exclaimed that this is
certainly electricity.

444
00:32:14,640 --> 00:32:16,760
"But how?"

445
00:32:16,760 --> 00:32:21,360
And to work out how a living thing
could produce electricity,

446
00:32:21,360 --> 00:32:27,000
he decided to make his own
artificial fish.

447
00:32:28,720 --> 00:32:30,200
These are his plans.

448
00:32:30,200 --> 00:32:35,880
Two Leiden jars shaped like the
fish which were buried under sand.

449
00:32:35,880 --> 00:32:41,240
When the sand was touched, they
discharged, giving a nasty shock.

450
00:32:41,240 --> 00:32:46,960
His model helped convince him that
the real torpedo fish was electric.

451
00:32:46,960 --> 00:32:50,880
But it still left him with
a nagging problem.

452
00:32:52,080 --> 00:32:56,160
Although both the real fish
and Cavendish's artificial one

453
00:32:56,160 --> 00:32:58,400
gave powerful electric shocks,

454
00:32:58,400 --> 00:33:02,240
the real fish never sparked.

455
00:33:02,240 --> 00:33:04,360
Cavendish was perplexed.

456
00:33:04,360 --> 00:33:07,200
How could it be the same
kind of electricity

457
00:33:07,200 --> 00:33:10,360
if they didn't both do the same
kinds of things?

458
00:33:12,720 --> 00:33:17,200
Cavendish spent the winter
of 1773 in his laboratory

459
00:33:17,200 --> 00:33:19,920
trying to come up with an answer.

460
00:33:19,920 --> 00:33:22,760
In the spring, he had a brainwave.

461
00:33:24,240 --> 00:33:27,960
Cavendish's ingenious answer was
to point out a subtle distinction

462
00:33:27,960 --> 00:33:32,640
between the amount
of electricity and its intensity.

463
00:33:32,640 --> 00:33:36,520
The real fish produced the same
kind of electricity.

464
00:33:36,520 --> 00:33:39,720
It is just that it was less intense.

465
00:33:39,720 --> 00:33:43,320
For a physicist like me,
this marks a crucial turning point.

466
00:33:43,320 --> 00:33:49,200
But it is the moment when two
genuinely innovative scientific
ideas first crop up.

467
00:33:49,200 --> 00:33:53,280
What Cavendish refers
to as the amount of electricity,

468
00:33:53,280 --> 00:33:56,280
we now call "electric charge".

469
00:33:56,280 --> 00:33:59,000
His intensity is what we call

470
00:33:59,000 --> 00:34:02,720
the potential difference
or "voltage".

471
00:34:05,360 --> 00:34:09,880
So the Leiden jar's shock was
high-voltage but low charge

472
00:34:09,880 --> 00:34:15,640
whereas the fish was low voltage
and high charge.

473
00:34:15,640 --> 00:34:18,960
It's possible
to actually measure that.

474
00:34:21,720 --> 00:34:25,120
Hiding at the bottom
of this tank under the sand

475
00:34:25,120 --> 00:34:28,720
is the Torpedo marmorata
and it's an electric ray.

476
00:34:28,720 --> 00:34:33,200
You can just see its eyes
protruding from the sand.

477
00:34:33,200 --> 00:34:35,520
This is a fully grown female

478
00:34:35,520 --> 00:34:37,880
and I am going to try and measure

479
00:34:37,880 --> 00:34:41,240
the electricity it gives off
with this bait.

480
00:34:41,240 --> 00:34:43,960
I have a fish connected to a
metal rod and hooked up

481
00:34:43,960 --> 00:34:45,440
to an oscilloscope

482
00:34:45,440 --> 00:34:49,120
to see if I can measure the voltage
as it catches its prey.

483
00:34:49,120 --> 00:34:51,160
Here goes!

484
00:35:03,720 --> 00:35:04,960
Oh! There's one!

485
00:35:10,800 --> 00:35:12,080
There's another one.

486
00:35:12,080 --> 00:35:15,480
The fish gave
a shock of about 240 volts,

487
00:35:15,480 --> 00:35:20,680
the same as mains electricity,
but still roughly 10 times less

488
00:35:20,680 --> 00:35:23,640
than the Leiden jar.

489
00:35:23,640 --> 00:35:26,080
That would have given me
quite a nasty shock

490
00:35:26,080 --> 00:35:29,240
and I can only try and imagine
what it must have been like

491
00:35:29,240 --> 00:35:32,320
for scientists in the 18th century
to witness this.

492
00:35:32,320 --> 00:35:36,920
An animal, a fish,
producing its own electricity.

493
00:35:39,680 --> 00:35:43,480
Cavendish had shown that the
torpedo fish made electricity

494
00:35:43,480 --> 00:35:46,960
but he didn't know if it was the
same kind of electricity

495
00:35:46,960 --> 00:35:49,840
as that made from
an electrical machine.

496
00:35:51,360 --> 00:35:54,880
Is the electrical shock
that a torpedo produces

497
00:35:54,880 --> 00:35:59,200
the same as produced
by an electrical machine?

498
00:35:59,200 --> 00:36:00,960
Or are there two kinds?

499
00:36:00,960 --> 00:36:05,000
A kind generated artificially or is
there a kind of animal electricity

500
00:36:05,000 --> 00:36:08,360
that only exists in living bodies?

501
00:36:08,360 --> 00:36:12,600
This was a huge debate that divided
opinion for several decades.

502
00:36:16,880 --> 00:36:21,600
Out of that bitter debate
came a new discovery.

503
00:36:21,600 --> 00:36:26,720
The discovery that electricity
needn't be a brief shock or spark.

504
00:36:26,720 --> 00:36:29,080
It could actually be continuous.

505
00:36:29,080 --> 00:36:32,960
And the generation
of continuous electricity

506
00:36:32,960 --> 00:36:35,760
would ultimately propel us
into our modern age.

507
00:36:48,480 --> 00:36:52,560
But the next step in the story
of electricity would come about

508
00:36:52,560 --> 00:36:56,640
because of a fierce personal
and professional rivalry

509
00:36:56,640 --> 00:36:59,080
between two Italian academics.

510
00:37:03,720 --> 00:37:08,480
BELL RINGS

511
00:37:14,640 --> 00:37:19,400
This is Bologna University,
one of the oldest in Europe.

512
00:37:19,400 --> 00:37:21,000
In the late 18th century,

513
00:37:21,000 --> 00:37:23,840
the city of Bologna was
ruled from papal Rome

514
00:37:23,840 --> 00:37:26,160
which meant that the
university was powerful

515
00:37:26,160 --> 00:37:27,960
but conservative in its thinking.

516
00:37:30,720 --> 00:37:34,480
It was steeped
in traditional Christianity,

517
00:37:34,480 --> 00:37:37,120
one where got ruled
earth from heaven

518
00:37:37,120 --> 00:37:39,360
but that the way he ran the world

519
00:37:39,360 --> 00:37:42,520
was hidden from us mere mortals

520
00:37:42,520 --> 00:37:46,280
who were not meant
to understand him,

521
00:37:46,280 --> 00:37:48,200
only to serve him.

522
00:37:48,200 --> 00:37:51,840
One of the university's
brightest stars

523
00:37:51,840 --> 00:37:54,840
was the anatomist
Luigi Aloisio Galvani.

524
00:37:54,840 --> 00:37:57,120
But, in a neighbouring city,

525
00:37:57,120 --> 00:38:01,480
a rival electrician
was about to take Galvani to task.

526
00:38:11,240 --> 00:38:14,680
This is Pavia,
only 150 miles from Bologna,

527
00:38:14,680 --> 00:38:17,400
but by the end of the 18th century,

528
00:38:17,400 --> 00:38:19,840
worlds apart politically.

529
00:38:19,840 --> 00:38:22,640
It was part of the Austrian
empire which put it

530
00:38:22,640 --> 00:38:25,680
at the very heart
of the European Enlightenment.

531
00:38:25,680 --> 00:38:28,120
Liberal in its thinking,
politically radical

532
00:38:28,120 --> 00:38:32,040
and obsessed with the new
science of electricity.

533
00:38:32,040 --> 00:38:35,360
It was also home to
Alessandro Volta.

534
00:38:39,960 --> 00:38:43,960
Alessandro Volta couldn't have been
more unlike Galvani.

535
00:38:43,960 --> 00:38:48,840
From an old Lombardi family,
he was young, arrogant, charismatic,

536
00:38:48,840 --> 00:38:50,200
a real ladies' man,

537
00:38:50,200 --> 00:38:52,360
and he courted controversy.

538
00:38:52,360 --> 00:38:56,080
Unlike Galvani, he liked
to show off his experiments

539
00:38:56,080 --> 00:38:59,200
on an international stage
to any audience.

540
00:38:59,200 --> 00:39:05,640
Volta's ideas were unfettered
by Galvani's religious dogma.

541
00:39:05,640 --> 00:39:09,040
Like Benjamin Franklin
and the European Enlightenment,

542
00:39:09,040 --> 00:39:11,600
he believed in rationality -

543
00:39:11,600 --> 00:39:13,560
that scientific truth,

544
00:39:13,560 --> 00:39:17,800
like a Greek god,
would cast ignorance to the floor.

545
00:39:17,800 --> 00:39:22,240
Superstition was the enemy.
Reason was the future.

546
00:39:25,640 --> 00:39:28,880
Both men were
fascinated by electricity.

547
00:39:28,880 --> 00:39:33,560
Both brought their different ways
of seeing the world to bear on it.

548
00:39:45,200 --> 00:39:49,000
Galvani had been attracted to
the use of electricity

549
00:39:49,000 --> 00:39:50,760
in medical treatments.

550
00:39:50,760 --> 00:39:53,840
For instance, in 1759,
here in Bologna,

551
00:39:53,840 --> 00:39:58,440
electricity was used on
the muscles of a paralysed man.

552
00:39:58,440 --> 00:40:01,840
One report said,

553
00:40:01,840 --> 00:40:07,120
"It was a fine sight to see
the mastoid rotate the head,

554
00:40:07,120 --> 00:40:09,920
"the biceps bend the elbow.

555
00:40:09,920 --> 00:40:14,240
"In short, to see the force
and vitality of all the motions

556
00:40:14,240 --> 00:40:18,960
"occurring in every paralysed
muscle subjected to the stimulus."

557
00:40:27,680 --> 00:40:30,760
Galvani believed
these kinds of examples

558
00:40:30,760 --> 00:40:35,080
revealed that the body
worked using animal electricity,

559
00:40:35,080 --> 00:40:37,880
a fluid that flows from the brain,

560
00:40:37,880 --> 00:40:40,480
through the nerves,
into the muscles,

561
00:40:40,480 --> 00:40:42,600
where it's turned into motion.

562
00:40:43,720 --> 00:40:48,280
He devised a series of
grisly experiments to prove it.

563
00:41:03,240 --> 00:41:05,880
Now, he first prepared a frog.

564
00:41:05,880 --> 00:41:09,760
He writes, "The frog is skinned
and disembowelled.

565
00:41:09,760 --> 00:41:12,440
"Only their lower limbs
are left joined together,

566
00:41:12,440 --> 00:41:15,040
"containing just the crural nerves."

567
00:41:15,040 --> 00:41:17,520
I've left my frog mostly intact,

568
00:41:17,520 --> 00:41:21,120
but I've exposed the nerves
that connect to the frog's legs.

569
00:41:21,120 --> 00:41:25,520
Then he used Hauksbee's
electrical machine

570
00:41:25,520 --> 00:41:28,480
to generate electrostatic charge,

571
00:41:28,480 --> 00:41:32,040
that would accumulate and travel
along this arm

572
00:41:32,040 --> 00:41:35,080
and out through this copper wire.

573
00:41:35,080 --> 00:41:39,400
Then he connected
the charge-carrying wire to the frog

574
00:41:39,400 --> 00:41:42,800
and another to the nerve
just above the leg.

575
00:41:43,800 --> 00:41:46,160
Let's see what happens.

576
00:41:48,320 --> 00:41:52,720
Ooh! And the frogs leg twitches,
just as it makes contact.

577
00:41:52,720 --> 00:41:53,920
There we go!

578
00:41:55,480 --> 00:42:01,080
For Galvani, what was going
on there was that there's a strange,

579
00:42:01,080 --> 00:42:05,640
special kind of entity
in the animal muscle,

580
00:42:05,640 --> 00:42:07,680
which he calls animal electricity.

581
00:42:07,680 --> 00:42:12,720
It's not like any other electricity.
It's intrinsic to living beings.

582
00:42:15,400 --> 00:42:21,640
But for Volta, animal electricity
smacked of superstition and magic.

583
00:42:21,640 --> 00:42:26,160
It had no place in rational
and enlightened science.

584
00:42:28,640 --> 00:42:33,080
Volta saw the experiment completely
differently to Galvani.

585
00:42:33,080 --> 00:42:36,720
He believed it revealed
something totally new.

586
00:42:36,720 --> 00:42:39,520
For him, the legs weren't jumping
as a result

587
00:42:39,520 --> 00:42:42,440
of the release of animal electricity
from within them,

588
00:42:42,440 --> 00:42:46,080
but because of the artificial
electricity from outside.

589
00:42:46,080 --> 00:42:49,480
The legs were merely the indicator.

590
00:42:49,480 --> 00:42:54,520
They were only twitching
because of the electricity
from the Hauksbee machine.

591
00:42:57,000 --> 00:43:02,240
Back in Bologna, Galvani
reacted furiously to Volta's ideas.

592
00:43:02,240 --> 00:43:06,440
He believed Volta had crossed
a fundamental line -

593
00:43:06,440 --> 00:43:10,280
from electrical experiments
into God's realm,

594
00:43:10,280 --> 00:43:13,720
and that was tantamount to heresy.

595
00:43:13,720 --> 00:43:17,400
To have a kind of spirit
like electricity,

596
00:43:17,400 --> 00:43:19,760
to have that produced artificially

597
00:43:19,760 --> 00:43:22,160
and to say that spirit,
that living force,

598
00:43:22,160 --> 00:43:26,320
that agency was the same
as something produced by God,

599
00:43:26,320 --> 00:43:30,400
that God had put into a living
human body or a frog's body,

600
00:43:30,400 --> 00:43:32,600
that seemed sacrilegious to them,

601
00:43:32,600 --> 00:43:35,200
because it was eliminating
this boundary

602
00:43:35,200 --> 00:43:37,480
between God's realm of the divine

603
00:43:37,480 --> 00:43:40,600
and the mundane realm
of the material.

604
00:43:43,800 --> 00:43:47,320
Spurred on by his
religious indignation,

605
00:43:47,320 --> 00:43:50,880
Galvani announced a new series
of experimental results,

606
00:43:50,880 --> 00:43:53,520
which would prove Volta was wrong.

607
00:43:55,080 --> 00:44:00,920
During one of his experiments,
he hung his frogs on an iron wire

608
00:44:00,920 --> 00:44:04,400
and saw something
totally unexpected.

609
00:44:04,400 --> 00:44:09,960
If he connected copper wire to
the wire the frog was hanging from,

610
00:44:09,960 --> 00:44:13,120
and then touched the other end
of the copper to the nerve...

611
00:44:14,960 --> 00:44:19,320
..it seemed to him he could make
the frog's legs twitch

612
00:44:19,320 --> 00:44:21,560
without any electricity at all.

613
00:44:28,680 --> 00:44:34,440
Galvani came to the conclusion
that it must have been

614
00:44:34,440 --> 00:44:39,000
something inside the frogs,
even if dead,

615
00:44:39,000 --> 00:44:42,120
that continued for a while
after death

616
00:44:42,120 --> 00:44:44,760
to produce some kind of electricity.

617
00:44:44,760 --> 00:44:50,080
And the metal wires were somehow
releasing that electricity.

618
00:44:51,720 --> 00:44:53,600
Over the next months,

619
00:44:53,600 --> 00:44:58,240
Galvani's experiments focused on
isolating this animal electricity

620
00:44:58,240 --> 00:45:01,080
using combinations
of frog and metal,

621
00:45:01,080 --> 00:45:03,680
Leiden jars
and electrical machines.

622
00:45:05,160 --> 00:45:09,320
For Galvani, these experiments
were proof the electricity

623
00:45:09,320 --> 00:45:12,840
was originating
within the frog itself.

624
00:45:12,840 --> 00:45:17,640
The frog's muscles were Leiden jars,
storing up the electrical fluid

625
00:45:17,640 --> 00:45:20,120
and then releasing it in a burst.

626
00:45:20,120 --> 00:45:25,840
On 30th October, 1786,
he published his findings in a book,

627
00:45:25,840 --> 00:45:31,320
Animali Electricitate -
Of Animal Electricity.

628
00:45:32,880 --> 00:45:35,800
Galvani was so confident
of his ideas,

629
00:45:35,800 --> 00:45:38,880
he even sent a copy of his book
to Volta.

630
00:45:41,040 --> 00:45:46,520
But Volta just couldn't stomach
Galvani's idea
of animal electricity.

631
00:45:46,520 --> 00:45:50,880
He thought the electricity just
had to come from somewhere else.

632
00:45:52,000 --> 00:45:53,040
But where?

633
00:46:04,360 --> 00:46:07,760
In the 1790s, here at
the University of Pavia,

634
00:46:07,760 --> 00:46:12,080
almost certainly in this lecture
theatre, which still bears his name,

635
00:46:12,080 --> 00:46:16,160
Volta began his search
for the new source of electricity.

636
00:46:18,320 --> 00:46:21,600
His suspicions focused on the metals

637
00:46:21,600 --> 00:46:24,680
that Galvani had used
to make his frog's legs twitch.

638
00:46:24,680 --> 00:46:30,680
His curiosity had been piqued by
an odd phenomenon he come across -

639
00:46:30,680 --> 00:46:33,920
how combinations of metals tasted.

640
00:46:36,360 --> 00:46:40,400
He found that if he took
two different metal coins

641
00:46:40,400 --> 00:46:42,760
and placed them on the tip
of his tongue,

642
00:46:42,760 --> 00:46:46,120
and then placed a silver spoon
on top of both...

643
00:46:47,840 --> 00:46:50,600
..he got
a kind of tingling sensation,

644
00:46:50,600 --> 00:46:54,160
rather like the tingling you'd get
from the discharge of a Leiden jar.

645
00:46:54,160 --> 00:46:57,960
Volta concluded
he could taste the electricity

646
00:46:57,960 --> 00:47:04,520
and it must be coming from the
contact between the different metals
in the coins and spoon.

647
00:47:04,520 --> 00:47:07,280
His theory flew in the face
of Galvani's.

648
00:47:07,280 --> 00:47:11,880
The frog's leg twitched, not because
of its own animal electricity,

649
00:47:11,880 --> 00:47:16,440
but because it was reacting to
the electricity from the metals.

650
00:47:16,440 --> 00:47:21,960
But the electricity his coins
generated was incredibly weak.

651
00:47:21,960 --> 00:47:24,000
How could he make it stronger?

652
00:47:28,160 --> 00:47:32,720
Then an idea came to him as he
revisited the scientific papers

653
00:47:32,720 --> 00:47:37,040
from the great British scientist,
Henry Cavendish,

654
00:47:37,040 --> 00:47:41,800
and in particular, his famous work
on the electric torpedo fish.

655
00:47:44,720 --> 00:47:49,560
He went back and took a closer
look at the torpedo fish

656
00:47:49,560 --> 00:47:53,880
and in particular, the repeating
pattern of chambers in its back.

657
00:47:53,880 --> 00:47:56,640
He wondered whether
it was this repeating pattern

658
00:47:56,640 --> 00:47:59,760
that held the key to its powerful
electric shock.

659
00:48:02,080 --> 00:48:06,080
Perhaps each chamber
was like his coins and spoon,

660
00:48:06,080 --> 00:48:10,400
each generating a tiny
amount of electricity.

661
00:48:10,400 --> 00:48:13,360
And, perhaps,
the fish's powerful shock

662
00:48:13,360 --> 00:48:19,120
results from the pattern of chambers
repeating over and over again.

663
00:48:20,160 --> 00:48:26,080
With growing confidence in his new
ideas, Volta decided to fight back

664
00:48:26,080 --> 00:48:31,400
by building his own artificial
version of the torpedo fish.

665
00:48:31,400 --> 00:48:36,040
So, he copied the torpedo
fish by repeating its pattern,

666
00:48:36,040 --> 00:48:38,400
but using metal.

667
00:48:38,400 --> 00:48:42,800
Here's what he did -
he took a copper metal plate

668
00:48:42,800 --> 00:48:47,480
and then placed above it a piece
of card soaked in dilute acid.

669
00:48:47,480 --> 00:48:51,160
Then above that, he took
another metal and placed it on top.

670
00:48:51,160 --> 00:48:56,120
What he had here was exactly the
same thing as Galvani's two wires.

671
00:48:56,120 --> 00:49:00,560
But now Volta repeated the process.

672
00:49:00,560 --> 00:49:04,800
What he was doing here
was building a pile of metal.

673
00:49:04,800 --> 00:49:09,360
In fact, his invention became
known as the pile.

674
00:49:14,080 --> 00:49:17,720
But it's what it could do that was
the really incredible revelation.

675
00:49:17,720 --> 00:49:22,400
Volta tried his pile out
on himself by getting two wires

676
00:49:22,400 --> 00:49:24,960
and attaching them
to each end of the pile

677
00:49:24,960 --> 00:49:27,720
and bringing the other ends
to touch his tongue.

678
00:49:30,000 --> 00:49:33,120
He could actually taste
the electricity.

679
00:49:33,120 --> 00:49:37,800
This time, it was more powerful
than normal and it was constant.

680
00:49:41,800 --> 00:49:45,840
He'd created the first battery.

681
00:49:45,840 --> 00:49:51,000
The machine was no longer an
electrical and mechanical machine,

682
00:49:51,000 --> 00:49:54,720
it was just purely
an electrical machine.

683
00:49:54,720 --> 00:49:58,640
So he proved that a machine
imitating the fish could work,

684
00:49:58,640 --> 00:50:03,400
that what he called
the metal or contact electricity

685
00:50:03,400 --> 00:50:05,840
of different metals could work,

686
00:50:05,840 --> 00:50:09,880
and that he regarded as his final,

687
00:50:09,880 --> 00:50:14,880
winning move in the controversy
with Galvani.

688
00:50:14,880 --> 00:50:19,680
What Volta's pile showed was that
you could develop all the phenomena

689
00:50:19,680 --> 00:50:24,560
of animal electricity
without any animals being present.

690
00:50:24,560 --> 00:50:30,280
So, from the Voltaic point of view,
it seemed as if Galvani was wrong,

691
00:50:30,280 --> 00:50:34,400
there's nothing special
about the electricity in animals.

692
00:50:34,400 --> 00:50:38,680
It's electricity
and it can be completely mimicked

693
00:50:38,680 --> 00:50:40,640
by this artificial pile.

694
00:50:43,120 --> 00:50:49,640
But the biggest surprise for Volta
was that the electricity
it generated was continuous.

695
00:50:49,640 --> 00:50:53,000
In fact, it poured out
like water in a stream.

696
00:50:53,000 --> 00:50:57,160
And just as in a stream, where
the measure of the amount of water

697
00:50:57,160 --> 00:51:00,720
flowing is called a current,
so the electricity flowing

698
00:51:00,720 --> 00:51:06,520
out of the pile became
known as an electrical current.

699
00:51:10,600 --> 00:51:13,920
200 years after Volta,

700
00:51:13,920 --> 00:51:17,200
we finally understand
what electricity actually is.

701
00:51:19,480 --> 00:51:23,880
The atoms in metals, like all atoms,
have electrically charged

702
00:51:23,880 --> 00:51:27,080
electrons surrounding a nucleus.

703
00:51:27,080 --> 00:51:30,560
But in metals, the atoms share
their outer electrons

704
00:51:30,560 --> 00:51:32,760
with each other in a unique way,

705
00:51:32,760 --> 00:51:36,160
which means they can move
from one atom to the next.

706
00:51:39,400 --> 00:51:43,760
If those electrons move in the same
direction at the same time,

707
00:51:43,760 --> 00:51:48,040
the cumulative effect
is a movement of electric charge.

708
00:51:50,040 --> 00:51:55,800
This flow of electrons
is what we call an electric current.

709
00:52:00,120 --> 00:52:03,920
Within weeks of Volta publishing
details of his pile,

710
00:52:03,920 --> 00:52:08,280
scientists were discovering
something incredible about
what it could do.

711
00:52:16,240 --> 00:52:20,240
Its effect on ordinary water
was completely unexpected.

712
00:52:20,240 --> 00:52:23,960
The constant stream of electric
charge into the water

713
00:52:23,960 --> 00:52:27,280
was ripping it up
into its constituent parts -

714
00:52:27,280 --> 00:52:30,640
the gases, oxygen and hydrogen.

715
00:52:30,640 --> 00:52:34,920
Electricity was heralding
the dawn of a new age.

716
00:52:34,920 --> 00:52:40,120
A new age where electricity
ceased being a mere curiosity

717
00:52:40,120 --> 00:52:44,680
and started being genuinely useful.

718
00:52:44,680 --> 00:52:47,360
With constant flowing
current electricity,

719
00:52:47,360 --> 00:52:51,200
new chemical elements
could be isolated with ease.

720
00:52:51,200 --> 00:52:56,880
And this laid the foundations
for chemistry, physics
and modern industry.

721
00:52:59,560 --> 00:53:02,880
Volta's pile changed everything.

722
00:53:08,040 --> 00:53:11,600
The pile made Volta
an international celebrity,

723
00:53:11,600 --> 00:53:15,840
feted by the powerful and the rich.

724
00:53:15,840 --> 00:53:17,080
In recognition,

725
00:53:17,080 --> 00:53:21,800
a fundamental measure of electricity
was named in his honour.

726
00:53:21,800 --> 00:53:22,840
The volt.

727
00:53:26,920 --> 00:53:32,040
But his scientific adversary
didn't fare quite so well.

728
00:53:32,040 --> 00:53:38,800
Luigi Aloisio Galvani
died on 4th December 1798,

729
00:53:38,800 --> 00:53:41,440
depressed and in poverty.

730
00:53:41,440 --> 00:53:45,160
For me, it's not
the invention of the battery

731
00:53:45,160 --> 00:53:49,600
that marked the crucial turning
point in the story of electricity,

732
00:53:49,600 --> 00:53:52,040
it's what happened next.

733
00:54:01,800 --> 00:54:05,200
It took place
in London's Royal Institution.

734
00:54:05,200 --> 00:54:09,080
It was the moment that marked
the end of one era

735
00:54:09,080 --> 00:54:11,120
and the beginning of another.

736
00:54:15,040 --> 00:54:17,720
It was overseen by Humphry Davy,

737
00:54:17,720 --> 00:54:21,280
the first of a new generation
of electricians.

738
00:54:21,280 --> 00:54:27,680
Young, confident and fascinated by
the possibilities of continuous
electrical current.

739
00:54:27,680 --> 00:54:34,080
So, in 1808, he built
the world's largest battery.

740
00:54:34,080 --> 00:54:37,680
It filled an entire room
underneath the Royal Institution.

741
00:54:37,680 --> 00:54:43,960
It had over 800 individual
voltaic piles attached together.

742
00:54:43,960 --> 00:54:48,760
It must have hissed
and breathed sulphurous fumes.

743
00:54:51,280 --> 00:54:58,320
In a darkened room,
lit by centuries-old technology,
candles and oil lamps,

744
00:54:58,320 --> 00:55:02,800
Davy connected his battery
to two carbon filaments

745
00:55:02,800 --> 00:55:05,440
and brought the tips together.

746
00:55:05,440 --> 00:55:08,200
The continuous flow of electricity
from the battery

747
00:55:08,200 --> 00:55:11,320
through the filaments
leapt across the gap,

748
00:55:11,320 --> 00:55:16,840
giving rise to a constant
and blindingly bright spark.

749
00:55:22,520 --> 00:55:27,040
Out of the darkness came the light.

750
00:55:38,840 --> 00:55:43,840
Davy's arc light truly symbolises
the end of one era

751
00:55:43,840 --> 00:55:46,680
and the beginning of our era.

752
00:55:46,680 --> 00:55:48,320
The era of electricity.

753
00:55:57,680 --> 00:56:04,280
But there's a truly grisly
coda to this story.

754
00:56:04,280 --> 00:56:08,280
In 1803, Galvani's nephew,
one Giovanni Aldini,

755
00:56:08,280 --> 00:56:12,920
came to London with
a terrifying new experiment.

756
00:56:12,920 --> 00:56:15,840
A convicted murderer
called George Forster

757
00:56:15,840 --> 00:56:18,120
had just been hanged in Newgate.

758
00:56:18,120 --> 00:56:21,040
When the body was cut down
from the gallows,

759
00:56:21,040 --> 00:56:23,680
it was brought directly
to the lecture theatre,

760
00:56:23,680 --> 00:56:27,040
where Aldini
started his macabre work.

761
00:56:30,240 --> 00:56:32,040
Using a voltaic pile,

762
00:56:32,040 --> 00:56:37,520
he began to apply an electric
current to the dead man's body.

763
00:56:37,520 --> 00:56:43,160
Then Aldini put one electrical
conductor in the dead man's anus

764
00:56:43,160 --> 00:56:45,920
and the other
at the top of his spine.

765
00:56:45,920 --> 00:56:50,160
Forster's limp, dead body
sat bolt upright

766
00:56:50,160 --> 00:56:52,960
and his spine arched and twisted.

767
00:56:52,960 --> 00:56:55,840
For a moment, it seemed as though
the dead body

768
00:56:55,840 --> 00:56:58,680
had been brought back to life.

769
00:57:00,240 --> 00:57:06,240
It appeared as though electricity
might have the power
of resurrection.

770
00:57:06,240 --> 00:57:11,560
And this made a profound impact on
a young writer called Mary Shelley.

771
00:57:17,040 --> 00:57:22,400
Mary Shelley wrote one of the most
powerful and enduring stories ever.

772
00:57:22,400 --> 00:57:24,680
Based partly here on Lake Como,

773
00:57:24,680 --> 00:57:27,640
Frankenstein tells
the story of a scientist,

774
00:57:27,640 --> 00:57:30,120
a Galvanist probably
based on Aldini,

775
00:57:30,120 --> 00:57:34,160
who brings a monster
to life using electricity.

776
00:57:34,160 --> 00:57:40,040
And then, disgusted by his own
arrogance, he abandons his creation.

777
00:57:40,040 --> 00:57:45,640
Just like Davy's arc lamp,
this book symbolises changing times.

778
00:57:45,640 --> 00:57:49,240
The end of the era of miracles
and romance

779
00:57:49,240 --> 00:57:54,440
and the beginning of the era of
rationality, industry and science.

780
00:58:06,240 --> 00:58:10,400
And it's that new age
we explore in the next programme,

781
00:58:10,400 --> 00:58:12,880
because at the start of
the 19th century,

782
00:58:12,880 --> 00:58:17,680
scientists realised electricity
was intimately connected

783
00:58:17,680 --> 00:58:21,320
with another of nature's
mysterious forces...

784
00:58:21,320 --> 00:58:22,440
magnetism.

785
00:58:23,480 --> 00:58:27,600
And that realisation would
completely transform our world.

786
00:58:29,640 --> 00:58:32,920
To find out more about
the story of electricity

787
00:58:32,920 --> 00:58:35,840
and to put your power knowledge
to the test,

788
00:58:35,840 --> 00:58:39,640
try the Open University's
interactive energy game.

789
00:58:39,640 --> 00:58:41,240
Go to...

790
00:58:44,640 --> 00:58:47,080
..and follow links
to the Open University.

791
00:59:09,320 --> 00:59:12,360
Subtitles by Red Bee Media Ltd

792
00:59:12,360 --> 00:59:15,400
E-mail subtitling@bbc.co.uk