All language subtitles for BBC.Shock.And.Awe.The.Story.Of.Electricity.2011.S01E01.Spark.AC3.2.0.x264.1080p.eng

At the dawn of the 19th
century, in a cellar in Mayfair,

the most famous scientist
of the time, Humphry Davy,

built an extraordinary piece
of electrical equipment.

Four meters wide, twice as long,

and containing stinking
stacks of acid and metal,

it had been created to
pump out more electricity

than had ever been possible before.

It was in fact the biggest battery

the world had ever seen.

With it, Davy was about to
propel us into a new age.

That moment would take place at a lecture

at the Royal Institution,

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

Filled with anticipation,
they packed the seats,

hoping to witness a new and
exciting electrical wonder.

But what they would see that night

would be something truly unique,

something they'd remember
for the rest of their lives.

Using just two simple carbon rods,

Humphry Davy was about to unleash

the true potential of electricity.

Electricity is one of nature's
most awesome phenomena,

and the most powerful manifestation of it

we ever see is lightning.

This is the story of how we first dreamed

of controlling this
primal force of nature,

and how we would ultimately
become its master.

It's a 300-year tale of
dazzling leaps of imagination

and extraordinary experiments.

Tens of thousands of volts

passed across his body

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

It's a story of maverick geniuses

who used electricity to light our cities,

to communicate across the
seas and through the air,

to create modern industry,

and to give us the digital revolution.

But in this film, we'll tell the story

of the very first scientists
who started to unlock

the mysteries of electricity.

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

They studied its curious link to life,

built strange and powerful
instruments to create it,

and even tamed lightning itself.

It was these men who
truly laid the foundations

of the modern world.

And it all started with a spark.

Imagine our world without electricity.

It would be dark, cold, and quiet.

In many ways,

it would be like the
beginning of the 18th century,

where our story begins.

This is the Royal Society in London.

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

Isaac Newton finally took control of it

after the death of his
archenemy, Robert Hooke.

Newton brought in his own
people to the key jobs,

to help shore up his new position.

The new head of demonstrations there

was 35-year-old Francis Hauksbee.

Notes from the Royal Society in 1705

reveal how hard Hauksbee tried

to stamp his personality
on its weekly meetings,

producing ever more
spectacular experiments

to impress his masters.

In November, he came up with
this, a rotating glass sphere.

He was able to remove
the air from inside it

using a new machine, the air pump.

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

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

and Francis placed his
hand against the sphere.

The audience were about
to see something amazing.

Inside the glass sphere,

a strange ethereal light began to form,

dancing around his hand,

a light no one had ever seen before.

Oh, that's fantastic.

You see a beautiful blue glow,

it's just marking out
the shape of my hands,

but then going right round the ball.

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

It's difficult to really understand

why this dancing blue light meant so much,

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

natural phenomena like this

were seen to be the work of the Almighty.

This was still a period when,

even in Isaac Newton's theory,

God was constantly intervening
in the conduct of the world.

And so it made sense for a lot of people

to interpret natural
phenomena as acts of God.

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

it was almost beyond
rational comprehension.

Hauksbee never realized
the full significance

of his experiment.

He lost interest in his glowing sphere

and spent the last few years of his life

building ever more spectacular experiments

for Isaac Newton to
test his other theories.

He never realized that he
had unwittingly started

an electrical revolution.

Before Hauksbee, electricity
had been merely a curiosity.

The ancient Greeks rubbed amber,
which they called electron,

to get small shocks.

And even Queen Elizabeth I

marveled at static electricity's
power to lift feathers.

But now Hauksbee's machine
could make electricity

at the turn of a handle,
and you could see it.

And perhaps even more importantly,
his invention coincided

with the birth of a new
movement sweeping across Europe

called the Enlightenment.

Enlightened intellectuals used
reason to question the world,

and their legacy was radical
politics, iconoclastic art

and natural philosophy, or science.

But ironically, Hauksbee's new machine

wasn't immediately embraced by
most of these intellectuals,

but instead, by conjurers
and street magicians.

And those with an interest in electricity

called themselves electricians.

One story tells of a dinner party

attended by an Austrian count.

The electrician had placed
some feathers on the table

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

He then astonished the guests

by lifting up the feathers with the rod.

He then went on to charge himself up

using one of Hauksbee's
electrical machines

and gave the guests electric shocks,

presumably to squeals of delight.

But for his piece de resistance,

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

charged himself up again,

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

There was a trick called
the electrical beatification,

in which the victim sits
on an insulated chair

and above his head hangs a metal crown

that doesn't quite touch his head.

And then if the crown is electrified,

then you get an electric
discharge around the crown

that looks exactly like a halo,

which is why it's called
the electric beatification.

As England and the rest of
Europe went electricity crazy,

the spectacles grew bigger.

And the more curious electricians

started to ask more profound questions,

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

but how can we control this amazing power?

And for some, can this
incredible electrical fire

do more than just entertain?

One of the first early breakthroughs

would never have happened

had it not been for a terrible accident.

This is Charterhouse in
the center of London.

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

for young orphans and elderly gentleman.

And sometime in the 1720s,

it also became home to one Stephen Gray.

Stephen Gray had been

a successful silk dyer from Canterbury.

He was used to seeing electric
sparks leap from the silk,

and they fascinated him.

Unfortunately, a crippling
accident ended his career

and left him destitute.

But then he was offered a
new life here at Charterhouse

and with it the time to perform

his own electrical experiments.

Here at Charterhouse,
possibly in this very room,

the Great Chamber, Stephen
Gray built a wooden frame,

and from the top beam
he suspended two swings

using silk rope.

He also had a device like this,

a Hauksbee machine for
generating static electricity.

Now, with a large audience in attendance,

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

to lie across the two swings.

Gray placed some gold
leaf in front of him.

He then generated electricity

and charged the boy
through a connecting rod.

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

Some of the audience claimed
they could even see sparks

flying out from his fingertips.

Show business indeed.

But to the curious and
inquiring mind of Stephen Gray,

this said something else as well:

Electricity could move, from
the machine to the boy's body,

through to his hands.

But the silk rope stopped it dead.

It meant the mysterious electrical fluid

could flow through some things,

but not through others.

It led Gray to divide the world

into two different kinds of substances.

He called them insulators and conductors.

Insulators held electric
charge within them

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

glass and resin,

whereas conductors allowed
electricity to flow through them,

like the boy or metals.

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

Just think of these electric pylons.

They work on the same
principle that Gray deduced

nearly 300 years ago.

The wires are conductors.

The glass and ceramic objects

between the wire and the metal
of the pylon are insulators

that stop the electricity
leaking from the wires

into the pylon and down to the earth.

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

Back in the 1730s,

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

but it had a frustrating drawback.

Try as he might, Gray couldn't
contain the electricity

he was generating for long.

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

The next step in our story came

when we learned how to store electricity.

But that would take place not in Britain,

but across the Channel in mainland Europe.

Across the Channel,
electricians were just as busy

as their British counterparts,

and one center for electrical research

was here in Leiden, Holland.

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

that many still regard
as the most significant

of the 18th century,

one that in some form or
another can still be found

in almost every electrical device today.

That professor was
Pieter van Musschenbroek.

Unlike Hauksbee and Gray,

Musschenbroek was born into academia.

But ironically enough,

his breakthrough came not
because of his rigorous science,

but because of a simple human mistake.

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

ready for his demonstrations.

And you can almost hear
his train of thought

as he tries to figure this out.

If electricity is a fluid
that flows, a bit like water,

then maybe you can store it

in the same way that you can store water.

So Musschenbroek went to his laboratory

to try to make a device
to store electricity.

Musschenbroek started to think literally.

He took a glass jar and
poured in some water.

He then placed inside it a
length of conducting wire,

which was connected at the top

to a Hauksbee electric machine.

Then he put the jar on an insulator

to help keep the charge in the jar.

He then tried to pour the
electricity into the jar

produced by the machine via the wire

down through into the water.

But whatever he tried,

the charge just wouldn't stay in the jar.

Then one day, by accident,

he forgot to put the jar on the insulator,

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

Finally, holding the jar with one hand,

he touched the top with the other

and received such a
powerful electric shock,

he was almost thrown to the ground.

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

"which I advise you never to try."

"Nor would I, who've experienced it"

"and survived by the grace of God,"

"do it again for all
the kingdom of France."

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

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

The sheer power of the electricity
which flew from the jar

was greater than any seen before.

And even more surprisingly,

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

So in honor of the city

where Musschenbroek made his discovery,

they called it the Leiden jar.

And its fame swept across the world.

And very rapidly, from 1745
through the rest of the 1740s,

the news of this, it's called
the Leiden jar, goes global.

It spreads from Japan in East Asia

to Philadelphia in eastern America.

It became one of the
first quick, globalized,

scientific news items.

But although the Leiden jar

became a global electrical phenomenon,

no one had the slightest
idea how it worked.

You have a jar of electric fluid,

and it turns out that you get
a bigger shock from the jar

if you allow the electric fluid
to drain away to the earth.

Why is the shock bigger
if the jar's leaking?

Why isn't the shock
bigger if you make sure

that all the electric
fluid stays inside the jar?

That was how mid-18th century
electrical philosophers

were faced with this challenge.

Electricity was without
doubt a fantastical wonder.

It could shock and spark.

It could now be stored and moved around.

Yet what electricity was, how it worked,

and why it did all these things,

was nothing less than a complete mystery.

Within 10 years, a new
breakthrough was to come

from an unexpected quarter,

from a man politically
and philosophically at war

with the London establishment.

And even more shockingly for
the British electrical elite,

that man was merely a colonial.

An American.

This painting of Benjamin Franklin

hangs here at the Royal Society in London.

Franklin was a passionate
supporter of American emancipation

and saw the pursuit of rational science,

and particularly electricity,

as a way of rolling back
ignorance, false idols,

and ultimately his intellectually
elitist colonial masters.

And this is mixed with

a profoundly egalitarian democratic idea

that Franklin and his allies have,

which is, this is a
phenomenon open to everyone.

"Here's something that the
elite doesn't really understand,

"and we might be able to understand it.

"Here's something that the
elite can't really control,

"but we might be able to control."

"And here's something above all"

"which is the source of superstition."

"And we, rational, egalitarian,"

"potentially democratic intellectuals,"

"we will be able to reason it out"

"without appearing to be the
slaves of magic or mystery."

So Franklin decided to
use the power of reason

to rationally explain what many considered

a magical phenomenon.

Lightning.

This is probably one of the
most famous scientific images

of the 18th century.

It shows Benjamin Franklin,
the heroic scientist,

flying a kite in a storm,

proving that lightning is electrical.

But although Franklin
proposed this experiment,

he almost certainly never performed it.

Much more likely is that his
most significant experiment

was another one which he
proposed but didn't even conduct.

In fact, it didn't even happen in America.

It took place here in a
small village north of Paris

called Marly La Ville.

The French adored Franklin,

especially his anti-British politics,

and they took it upon themselves

to perform his other lightning
experiments without him.

I've come to the very spot where
that experiment took place.

In May 1752, George Louis Leclerc,

known across France as
the Compte de Buffon,

and his friend Thomas Francois Dalibard,

erected a 40-foot metal pole,

more than twice as high as this one,

held in place by three wooden staves,

just outside Dalibard's house
here in the Marly La Ville.

The metal pole rested at the bottom

inside an empty wine bottle.

Franklin's big idea had
been that the long pole

would capture the lightning,
pass it down the metal rod,

and store it in the
wine bottle at the base,

which worked as a Leiden jar.

Then, he could confirm what
lightning actually was.

All his French followers had
to do was wait for a storm.

And then on May 23rd, the heavens opened.

At 12:20, a loud thunderclap was heard

as lightning hit the top of the pole.

An assistant ran to the bottle.

A spark leapt across between
the metal and his finger

with a loud crack and a sulfurous
smell, burning his hand.

The spark revealed lightning
for what it really was.

It was the same as the
electricity made by man.

It's hard to overestimate the
significance of this moment.

Nature had been mastered.

Not only that but the wrath of God itself

had been brought under
the control of mankind.

It was a kind of heresy.

Franklin's experiment was very important

because it showed that
lightning storms produce

or are produced by electricity

and that you can bring
this electricity down,

that electricity is a force of nature

that's waiting out there to be tapped.

Next, Franklin
turned his rational mind

to another question,

why the Leiden jar made the biggest sparks

when it was held in the hand?

Why didn't all the
electricity just drain away?

In drawing on his experience
as a successful businessman,

he saw something no one else had,

that like money in a bank,

electricity can be in credit,
what he called positive,

or debit, negative.

For him, the problem of the Leiden jar

is a problem of accountancy.

Franklin's idea was every body

has around it an electrical atmosphere.

And there's a natural
amount of electric fluid

around each body.

If there's too much,
we'll call it positive.

If there's too little,
we'll call it negative.

And nature is organized so the
positives and the negatives

always want to balance out,

like an ideal American economy.

Franklin's insight was that electricity

was actually just positive charge

flowing to cancel out negative charge.

And he believed this simple idea

could solve the mystery of the Leiden jar.

As the jar is charged up,

negative electrical charge
is poured down the wire

and into the water.

If the jar rests on an insulator,

a small amount builds up in the water.

But, if instead the jar is held by someone

as it's being charged,

positive electric charge is
sucked up through their body

from the ground to the outside of the jar,

trying to cancel out the
negative charge inside.

But the positive and negative charges

are stopped from canceling
out by the glass,

which acts as an insulator.

So instead, the charge
just grows and grows

on both sides of the glass.

Then, touching the top of
the jar with the other hand

completes a circuit,

allowing the negative charge on the inside

to pass through the hand to
the positive on the outside,

finally canceling it out.

The movement of this charge
causes a massive shock

and often a spark.

The modern equivalent of the Leiden jar

is this, the capacitor,

and it's one of the most ubiquitous

of electronic components.

It's found everywhere.

There are a number of
smaller ones scattered around

on this circuit board from a computer.

They help smooth out electrical surges,

protecting sensitive components,

even in the most modern electric circuit.

Solving the mystery of the Leiden jar

and recognizing lightning as
merely a kind of electricity

were two great successes for Franklin

and the new Enlightenment movement.

But the forces of trade and commerce,

which helped fuel the Enlightenment,

were about to throw up a new

and even more perplexing
electrical mystery,

a completely new kind of electricity.

This is the English Channel.

By the 17th and 18th centuries,

a good fraction of the world's wealth

flowed up this stretch of water

from all corners of the
British Empire and beyond

on its way to London.

Spices from India, sugar
from the Caribbean,

wheat from America, tea from China.

But of course, it wasn't just commerce.

New plants and animal specimens
from all over the world

came flooding into London,

including one that particularly
fascinated the electricians.

Called the torpedo fish,

it'd been the stuff of fishermen's tales.

Its sting, it was said,

was capable of knocking a grown man down.

But as the electricians started
to investigate the sting,

they realized it felt strangely similar

to a shock from a Leiden jar.

Could its sting actually
be an electric shock?

At first, many people dismissed

the torpedo fish's shock as occult.

Some said it was probably
just the fish biting.

Others that it could
not be a shock because,

without a spark, it
just wasn't electricity.

But, for most, this was a very strange

and inexplicable new mystery.

And it would take one of the oddest

yet most brilliant
characters in British science

to begin to unlock the
secrets of the torpedo fish.

This is the only picture in existence

of the pathologically shy but
exceptional Henry Cavendish.

This one only exists because
an artist sketched his coat

as it hung on a peg, then
filled in the face from memory.

His family were fantastically rich.

They were the Devonshires,

who still own Chatsworth
House in Derbyshire.

But Henry Cavendish
decided to turn his back

on his family's wealth and status

to live in London near
his beloved Royal Society

where he could quietly pursue his passion

for experimental science.

When he heard about the
electric torpedo fish,

he was intrigued.

A friend wrote to him,

"On this, my first experience
of the effect of the torpedo,"

"I exclaimed that this
is certainly electricity."

"But how?"

And to work out how a living thing

could produce electricity,

he decided to make his
own artificial fish.

These are his plans.

Two Leiden jars shaped like the fish

which were buried under sand.

When the sand was
touched, they discharged,

giving a nasty shock.

His model helped convince him

that the real torpedo fish was electric.

But it still left him
with a nagging problem.

Although both the real fish
and Cavendish's artificial one

gave powerful electric shocks,

the real fish never sparked.

Cavendish was perplexed.

How could it be the
same kind of electricity

if they didn't both do
the same kinds of things?

Cavendish spent the winter
of 1773 in his laboratory

trying to come up with an answer.

And in the spring, he had a brainwave.

Cavendish's ingenious
answer was to point out

a subtle distinction between
the amount of electricity

and its intensity.

The real fish produced the
same kind of electricity.

It's just that it was less intense.

Now, for a physicist like me,

this marks a crucial turning point,

because it's the moment

when two genuinely
innovative scientific ideas

first crop up.

What Cavendish refers to as
the amount of electricity,

we now call electric charge.

And his intensity is what we call

the potential difference, or voltage.

So the Leiden jar's shock was
high voltage but low charge,

whereas the fish was low
voltage and high charge.

And it's possible to
actually measure that.

Hiding at the bottom of
this tank under the sand

is the Torpedo marmorata,
and it's an electric ray.

You can just see its eyes
protruding from the sand.

This is a fully grown
female, and I am going to try

and measure the electricity
it gives off with this bait.

I've got this fish
connected to a metal rod

and hooked up to an oscilloscope

to see if I can measure the
voltage as it catches its prey.

So here goes.

Oh, there's one!

And there's another one!

The fish gave a shock of about 240 volts,

the same as mains electricity,

But still roughly 10 times less

than the Leiden jar.

Well, that would have given
me quite a nasty shock,

and I can only try and imagine
what it must have been like

for scientists in the 18th
century to witness this.

An animal, a fish, producing
its own electricity.

Cavendish had shown that the
torpedo fish made electricity,

but he didn't know if it was
the same kind of electricity

as that made from an electrical machine.

Is the electrical shock
that a torpedo produces,

is it the same as produced
by an electrical machine?

Or are there two kinds?

Is there a kind that's
generated artificially,

or is there a kind of animal electricity

that only exists in living bodies?

And this was a huge debate
that divided opinion

for several decades.

And out of that bitter
debate came a new discovery,

the discovery that electricity

needn't be a brief shock or spark,

but could actually be continuous.

And the generation of
continuous electricity

would ultimately propel
us into our modern age.

But the next step in
the story of electricity

would come about because
of a fierce personal

and professional rivalry
between two Italian academics.

This is Bologna University,
one of the oldest in Europe.

In the late 18th century,

the city of Bologna was
ruled from papal Rome,

which meant that the
university was powerful

but conservative in its thinking.

It was steeped in
traditional Christianity,

one where God ruled Earth from heaven,

but that the way he ran the world

was hidden from us mere mortals,

who were not meant to understand
him, only to serve him.

And one of the university's
brightest stars

was the anatomist Luigi Aloisio Galvani.

But in a neighboring city,

a rival electrician was about
to take Galvani to task.

This is Pavia, only
150 miles from Bologna,

but by the end of the 18th century,

worlds apart politically.

It was part of the Austrian
empire, which put it

at the very heart of the
European Enlightenment,

liberal in its thinking,
politically radical,

and obsessed with the new
science of electricity.

It was also home to Alessandro Volta.

Alessandro Volta couldn't
have been more unlike Galvani.

From an old Lombardi family,

he was young, arrogant,
charismatic, a real ladies' man,

and he courted controversy.

Unlike Galvani, he liked
to show off his experiments

on an international stage to any audience.

Volta's ideas were unfettered
by Galvani's religious dogma.

Like Benjamin Franklin and
the European Enlightenment,

he believed in rationality,

that scientific truth, like a Greek god,

would cast ignorance to the floor.

Superstition was the enemy.

Reason was the future.

Both men were fascinated by electricity,

and both brought their different
ways of seeing the world

to bear on it.

Galvani had been attracted
to the use of electricity

in medical treatments.

For instance, in 1759, here in Bologna,

electricity was used on the
muscles of a paralyzed man.

One report said,

"It was a fine sight to see
the mastoid rotate the head,"

"the biceps bend the elbow."

"In short, to see the force
and vitality of all the motions"

"occurring in every paralyzed muscle"

"subjected to the stimulus."

Galvani believed these kinds of examples

revealed that the body worked
using animal electricity,

a fluid that flows from the brain,

through the nerves, into the muscles,

where it's turned into motion.

And he devised a series of
grisly experiments to prove it.

Now, he first prepared a frog.

He writes, "The frog is
skinned and disemboweled."

"Only their lower limbs
are left joined together,"

"containing just the crural nerves."

Well, I've left my frog mostly intact,

but I've exposed the nerves
that connect to the frog's legs.

Then he used Hauksbee's electrical machine

to generate electrostatic charge

that would accumulate
and travel along this arm

and out through this copper wire.

Then he connected the
charge-carrying wire to the frog

and another to the nerve
just above the leg.

Let's see what happens.

Ooh!

And the frogs leg twitches,
just as it makes contact.

There we go.

Now, for Galvani,
what was going on there

was that there's a strange,
special kind of entity

in the animal muscle, which
he calls animal electricity.

It's not like any other electricity.

It's intrinsic to living beings.

But for Volta,

animal electricity smacked
of superstition and magic.

It had no place in rational
and enlightened science.

Volta saw the experiment
completely differently to Galvani.

He believed it revealed
something totally new.

For him, the legs weren't
jumping as a result

of the release of animal
electricity from within them,

but because of the artificial
electricity from outside.

The legs were merely the indicator.

They were only twitching
because of the electricity

from the Hauksbee machine.

Back in Bologna, Galvani reacted
furiously to Volta's ideas.

He believed Volta had
crossed a fundamental line,

from electrical experiments

into God's realm, and that
was tantamount to heresy.

To have a kind of
spirit like electricity,

to have that produced artificially

and to say that that
spirit, that living force,

that agency was the same as
something produced by God,

that God had put into a living
human body or a frog's body,

that seemed sacrilegious to them,

because it was eliminating this boundary

between God's realm of the divine

and the mundane realm of the material.

Spurred on by his religious indignation,

Galvani announced a new series
of experimental results,

which would prove that Volta was wrong.

During one of his experiments,

he hung his frogs on an iron wire

and saw something totally unexpected.

If he connected a copper wire

to the wire the frog was hanging from,

and then touched the other end
of the copper to the nerve,

It seemed to him that he could
make the frog's leg twitch

without any electricity at all.

Galvani came to the conclusion
that it must have been

something inside the frogs, even if dead,

that continued for a while after death

to produce some kind of electricity.

And the metal wires

were somehow releasing that electricity.

Over the next months,
Galvani's experiments

focused on isolating
this animal electricity

using combinations of frog and metal,

Leiden jars and electrical machines.

For Galvani, these experiments were proof

that the electricity was
originating within the frog itself.

The frog's muscles were Leiden jars,

storing up the electrical fluid

and then releasing it in a burst.

On the 30th of October, 1786,

he published his findings in a book,

"De Animali Electricitate,"
"Of Animal Electricity."

Galvani was so confident of his ideas,

he even sent a copy of his book to Volta.

But Volta just couldn't
stomach Galvani's idea

of animal electricity.

He thought the electricity
just had to come

from somewhere else.

But where?

In the 1790s, here at
the University of Pavia,

almost certainly in this lecture theater,

which still bears his name,

Volta began his search for
the new source of electricity.

His suspicions focused on the metals

that Galvani had used to
make his frogs' legs twitch.

His curiosity had been
piqued by an odd phenomenon

that he'd come across, how
combinations of metals tasted.

He found that if he took
two different metal coins

and placed them on the tip of his tongue,

and then placed a silver
spoon on top of both,

he got a kind of tingling sensation,

rather like the tingling you'd get

from the discharge of a Leiden jar.

Volta concluded he
could taste electricity,

and it must be coming from the contact

between the different metals
in the coins and spoon.

His theory flew in the face of Galvani's.

The frog's leg twitched,

not because of its own animal electricity,

but because it was
reacting to the electricity

from the metals.

But the electricity his coins
generated was incredibly weak.

How could he make it stronger?

Then an idea came to him

as he revisited the scientific papers

from the great British
scientist, Henry Cavendish,

and in particular, his famous work

on the electric torpedo fish.

He went back and took a closer
look at the torpedo fish

and in particular, the
repeating pattern of chambers

in its back.

He wondered whether it
was this repeating pattern

that held the key to its
powerful electric shock.

Perhaps each chamber was
like his coins and spoon,

each generating a tiny
amount of electricity.

And perhaps the fish's powerful shock

results from the pattern of chambers

repeating over and over again.

With growing confidence in his new ideas,

Volta decided to fight back

by building his own artificial
version of the torpedo fish.

So he copied the torpedo fish
by repeating its pattern,

but using metal.

Here's what he did.

He took a copper metal plate
and then placed above it

a piece of card soaked in dilute acid.

Then above that, he took another
metal and placed it on top.

What he had here was
exactly the same thing

as Galvani's two wires.

But now Volta repeated the process.

What he was doing here was
building a pile of metal.

In fact, his invention
became known as the pile.

But it's what it could do

that was the really incredible revelation.

Volta then tried his pile out on himself

by getting two wires and attaching them

to each end of the pile

and bringing the other
ends to touch his tongue.

He could actually taste the electricity.

This time, it was more
powerful than normal

and it was constant.

He'd created the first battery.

The machine was no longer

an electrical and mechanical machine,

it was just purely an electrical machine.

So he proved that a machine
imitating the fish could work,

that what he called the
metal or contact electricity

of different metals could work,

and that he regarded as his final,

winning move in the
controversy with Galvani.

What Volta's pile showed
was that you could develop

all the phenomena of animal electricity

without any animals being present.

So, from the Voltaic point of view,

it seemed as if Galvani was wrong,

there's nothing special about
the electricity in animals.

It's electricity and it
can be completely mimicked

by this artificial pile.

But the biggest surprise for Volta

was that the electricity it
generated was continuous.

In fact, it poured out
like water in a stream.

And just as in a stream, where the measure

of the amount of water
flowing is called a current,

so the electricity flowing out of the pile

became known as an electrical current.

200 years after Volta,

we finally understand what
electricity actually is.

The atoms in metals, like all atoms,

have electrically charged
electrons surrounding a nucleus.

But in metals, the atoms
share their outer electrons

with each other in a unique way,

which means they can move
from one atom to the next.

If those electrons move
in the same direction

at the same time, the cumulative effect

is a movement of electric charge.

This flow of electrons is what
we call an electric current.

Within weeks of Volta
publishing details of his pile,

scientists were discovering
something incredible

about what it could do.

Its effect on ordinary water
was completely unexpected.

The constant stream of
electric charge into the water

was ripping it up into
its constituent parts,

the gases oxygen and hydrogen.

Electricity was heralding
the dawn of a new age,

a new age where electricity
ceased being a mere curiosity

and started being genuinely useful.

With constant flowing current electricity,

new chemical elements could
be isolated with ease.

And this laid the foundations
for chemistry, physics,

and modern industry.

Volta's pile changed everything.

The pile made Volta an
international celebrity,

feted by the powerful and the rich.

In recognition, a fundamental
measure of electricity

was named in his honor.

The volt.

But his scientific adversary
didn't fare quite so well.

Luigi Aloisio Galvani died
on the 4th of December, 1798,

depressed and in poverty.

For me, though, it's not
the invention of the battery

that marked the crucial turning point

in the story of electricity,
it's what happened next.

It took place in London's
Royal Institution.

It was a moment that
marked the end of one era

and the beginning of another.

It was overseen by Humphry Davy,

the first of a new
generation of electricians,

young, confident, and
fascinated by the possibilities

of continuous electrical current.

So in 1808, he built the
world's largest battery.

It filled an entire room
underneath the Royal Institution.

It had over 800 individual
voltaic piles attached together.

It must have hissed and
breathed sulfurous fumes.

In a darkened room, lit by
centuries-old technology,

candles and oil lamps,

Davy connected his battery
to two carbon filaments

and brought the tips together.

The continuous flow of
electricity from the battery

through the filaments
leapt across the gap,

giving rise to a constant
and blindingly bright spark.

Out of the darkness came the light!

Davy's arc light truly
symbolizes the end of one era

and the beginning of our era,

the era of electricity.

But there's a truly
grisly coda to this story.

In 1803, Galvani's nephew,
one Giovanni Aldini,

came to London with a
terrifying new experiment.

A convicted murderer called George Forster

had just been hanged in Newgate.

And when the body was cut
down from the gallows,

it was brought directly
to the lecture theater,

where Aldini started his macabre work.

Using a voltaic pile, he began
to apply an electric current

to the dead man's body.

Then Aldini put one electrical conductor

in the dead man's anus

and the other at the top of his spine.

Forster's limp, dead body sat bolt upright

and his spine arched and twisted.

For a moment, it seemed
as though the dead body

had been brought back to life.

It appeared as though electricity

might have the power of resurrection.

And this made a profound impact

on a young writer called Mary Shelley.

Mary Shelley wrote one
of the most powerful

and enduring stories ever.

Based partly here on Lake Como,

"Frankenstein" tells the
story of a scientist,

a Galvanist probably based on Aldini,

who brings a monster to
life using electricity.

And then, disgusted by his own arrogance,

he abandons his creation.

Just like Davy's arc lamp,

this book symbolizes changing times,

the end of the era of miracles and romance

and the beginning of
the era of rationality,

industry, and science.