All language subtitles for BBC Light Fantastic (2004)The Stuff of Light 1

The world at night
seen from outer space.

Millions of lights glitter
across the surface of the globe.

And in these twinkling lights is the story
of how light created the modern world.

About 150 years ago,
light stopped living in

heaven and started living
in the material world.

It became a kind of good you could
buy and sell. It was artificial.

And mastering artificial light has unlocked
the secret of light itself, a secret so

extraordinary that
it would revolutionize

our understanding of
the way the world works.

But it's come at a price that we
are still learning to live with.

In 1847, a 16 year old Edinburgh
schoolboy was taken to see

one of the minor scientific
wonders of the Victorian world.

It was this, a prism made from a
special crystal found in Iceland and

what it did was something completely
surprising to scientists at the time.

It played tricks with light.
It is transparent, it lets

the light through. Nothing
puzzling there, but wait.

two of these crystals, combined, make the
light go out. They extinguish the light.

Light seemed to be violating
all the known laws of nature.

Now the Scottish schoolboy
was called James Clerk Maxwell.

And his fascination with what the
strange crystals did to light set him on a

journey that would unravel the mysterious
and astonishing nature of light itself.

Maxwell lived at a time when Britain
was the workshop of the world.

Its traders, merchants, and
engineers dominated the globe.

They understood how heat,
pressure, and sound worked.

Its architect could build the
most extraordinary structures, they

could bring light into the interior
of the very buildings themselves.

Yet, light itself baffled them.

Maxwell was captivated
by mysteries like this.

Young Maxwell liked playing with
things, he wanted to know their

particular goal, it was a phrase
that was never out of his mouth.

He would look at bells
and locks and keys, and how

water flowed, and the
strange properties of light.

and so he set about making
his own optical instruments to

explore the peculiar properties
of the Iceland crystals.

What we now know as polarizing lenses.

It is based on very simple idea. The
light falls onto this mirror here and

then along the tube, and you can look
it through a second mirror at the end.

Now Maxwell wasn't that
concerned with the fact that

polarization allows light
through or else it stops it.

That wasn't the primary concern for
him. No. What he wanted to do was

to use this device to see things
you couldn't see with the naked eye.

He started with a seemingly
unremarkable piece of glass.

Maxwell would heat it unit it
was red hot, far too hot to touch,

and then plunge it into ice cold
water that it would suddenly set.

There will be lines of tension
inside the glass, we can't

see them, but when Maxwell
put them into his instrument,

and then looked through the mirrors, what
he saw were the most amazing patterns.

These are frozen stress lines, things
you just can't see with the naked eye.

But with Maxwell's
instrument, this crucial lines

of frozen stress become
visible and beautiful.

How could brute physical forces affect
something as intangible as light?

And we know just how fascinated he was,
because we've got here the watercolors

that he did himself when young, of the
colors he could see through his instruments.

These colors were speaking to Maxwell.

cause what they suggested was that there
must be some kind of relationship between

the forces acting inside some stuff like
glass and the way light traveled through it,

and that was really odd. What could
be the relationship between pressure

and tension, and the way light
traveled, and the colors that it showed.

Light was posing a series
of problems for people,

they just didn't seem to
be smart enough to solve.

Only a couple of years
before the young Maxwell

had started working with
those polarizing prisms,

light had posed a really big
challenge that was very hard to

understand. It was this experiment
here, again he used Nicol prisms.

Between the prisms, you put a piece of very
heavy glass, and you shine lights through

the prisms and the glass. What you do now
is put a very strong electromagnet near it.

And when you turn the
magnet on, the light changes.

Now this was a very, very peculiar
phenomenon. How could magnets affect light?

And there were yet other
mysteries to do with light.

When it was well known that light heats
thing up a bit, but it turned out that stuff

would get really warm
through some kind of

radiation even where you
couldn't see any light.

What was the curious relationship
between light and heat?

And light sensitive
paper would turn black,

even though there was
no visible light around.

It was as though there was much more
to light than met the eye. Light was

the trickster, it was the central
problem for physicists to understand.

The riddles set by
light became a standing

provocation to the confidence
of Victorian scientists.

If they could solve what
light was, they could pull

together chemistry and mechanics,
electricity and magnetism.

Solving the problems of
light would put them on the

path to the first, adequate,
unified theory of the world.

It became one of the hottest
topics in Victorian science.

So when Maxwell went to
Cambridge university, light was

almost inevitably one of
his main areas of his study.

Maxwell has come down to
us as an odd character,

he pondered the math of
why cats always fall on

their feet. And why paper
fell in particular patterns.

Could there be some kind of law
behind them that would enable

him to draw up universal
rules for how the world worked.

He even tried his hand
on poetry, though, as

history will probably judge,
with much less success.

When the telegraph cable under the Atlantic
failed to work, Maxwell wrote an ode.

Under the see, no little
signals are coming to

me. Under the sea, something
has surely gone wrong.

And its broke, broke, broke,
what is the cause of it doesn't

transpire, but something has
broken the telegraph wire.

Yet behind the amateur versifier was a
brilliant analytical mind, which was to fuse

two traditions, which until now had never
seen eye to eye: math and engineering.

Down here in the university of Cambridge
of bastion of the church of England,

it was as though the industrial revolution
had never happened, not only that,

but there were whole
sciences that really mattered

to engineering like the
science of heat, the steam

engines, or electricity
and magnetism. They were

simply banned from the
undergraduate curriculum.

Because they were too
radical, they were too new

for the sensitive palates
of Cambridge undergraduate.

So when Maxwell arrived here, he
knew what he was in for, he brought

his own equipment with him, his own
prisms and lenses and polarimeters

In family letters, he
called them his dirt as

though he really
understood the way in which

Cambridge dons might think
about what engineering

meant in a bastion of
theology and mathematics.

The clash of these two
traditions would enable

Maxwell to explore light
in a totally new way.

Yet surprisingly, the biggest
revelation about light would

come from another problem that
fascinated Victorian society,

the relation between
electricity and magnetism.

In 1831, Michael Faraday had
demonstrated that if you wave a magnet

near a coil of copper wire, it
would produce an electric current.

What nobody could explain was why.

Maxwell set about looking for
a mathematical explanation.

He had to invent a new
mathematical language.

And what this gave him, after huge amount
of work, were four stunning equations that

showed for the first time the precise

relationship between
electricity and magnetism.

But there was more, because hidden in them
was something else: the truth about light.

The particular excitement
about this set of equations

is that they start off by
describing the phenomena

not of light, but of
electricity and magnetism.

If you represent the way
in which electrical and

magnetic forces interacts
with these 4 equations,

you start to see, as Maxwell gradually
realized with extraordinary excitement

that light, electricity, and magnetism
have something to do with each other,

but then there is more, an extraordinary
sudden moment of realization

that this number, which appears
in the equations, describes

the speed, with which waves
travel in electromagnetic space,

and it turns out, Maxwell was
astonished, it turns out that speed

with which these waves moved is
exactly the same as the speed of light.

There could only be one explanation.

Light, electricity, and magnetism
must be the same kind of thing.

Light is an electromagnetic wave.

It is one of the biggest insights into how
the world works in the history of science.

Most of his contemporaries
found it impossible to grasp.

People stumbled along
behind him in his wake,

either not understanding his
lectures, or simply not being able

to follow the leaps of imagination
which Maxwell engaged in.

When he was a student, and when he was
a professor, what his colleagues used to

say about him was that, Maxwell is always
right, but you can't always see why.

That Maxwell never made a mistake, but
it was impossible to check exactly how

he got from where he started to the
startling ideas with which he ended up.

Yet for Maxwell, the world now
fitted together beautifully.

If light is an electromagnetic
wave, then the different colors of

the spectrum correspond to waves
vibrating in different frequencies.

There is red at one end, this is the
light that is vibrating pretty slowly.

And then as the speed
of vibration increases,

we see the colors from red
to orange, all the way up to

blue and violet. Violet light
vibrating extremely fast.

Other mysteries also
fell into place like the

apparent presence of light
even when it can't be seen.

Beyond the edges of what we can
see, beyond the visible spectrum,

there are something very
spooky indeed. There is

invisible light. There
is radiation we can't see.

Faster than blue, faster than
violet, there is ultraviolet light.

It was this form of invisible light that
was mysteriously fogging photographic paper.

At the other end, vibrating slower than
the red is infrared, heat radiation.

This is the mysterious source of heat that
scientists had found associated with light.

The spectrum gets wider and wider,

the very neatness of the whole edifice
gave Maxwell enormous satisfaction.

One of the things that Maxwell
thought was that there is a really deep

relationship between the beauty of
mathematics and the reality of his science.

If something is true,
Maxwell reckoned, you

must be able to express
it in an aesthetic form,

and that is what the
equations are doing for him.

They summarize this idea that there is
a profound relationship between the way

the world works and our understanding
that the way the world works is beautiful.

In the years to come, these 4
equations would have enormous impact.

They would influence every new
technological development for ever after.

The relation between light and civilization
has always been pretty important,

but after Maxwell's equations, nothing
was ever gonna be the same again.

He was gonna bring light into
dark corners, and his tools and

techniques would going to completely
change the history of the world.

Society was about to change forever,

but not necessarily for the better.

Maxwell's equations
arrived at a time when

Victorian Britain was hungry
for new forms of light.

Gas was hot, smelly, and
occasionally dangerous.

Now there was a serious alternative.

Maxwell's equations unlocked the
potentiality of electromagnetism.

What could now happen was that
people could master magnets

to generate a constant and
reliable electrical supply.

And that electrical supply at
last made electric lighting viable.

It is a really good example of
the way in which something that

might seem abstract and out of
this world is brought down to earth.

Intelligent and inventive
men would be able to

exploit the potential
and make lots of money.

One of these men was a chemist,
working in the north of England.

Newcastle was a boom
city of the 19th century.

It was full of
entrepreneurs and businessman

with an eye on the main
chance and the learning

and skill to follow any
business opportunity.

One of them was a local
manufacturing chemist, Joseph Swan.

A gentleman of letters, but
with the keen eye to spot

any commercial opportunity
that would come his way.

Victorian engineers were
already experimenting with

primitive ways of using
electricity to make light.

Electric light pulled in
enormous number of people's

interests, it drew on state
of the art engineering,

but the problem was that the current form
of electric light in use, arc lighting,

just wasn't cut it. It didn't really work.
It was unstable, it was noisy, it burst.

There had to be a better way of bringing

illumination into the
home and into the factory.

Swan set about finding a solution.

One alternative to lighting by electric
sparks would be to use the fact that

some substance is glowed, they incandesce
when you pass electricity through them.

The problem with that kind of
electric glow is that anything

that glows so brightly is
likely to burn and disappear.

The solution would be to
get it to glow in a vacuum

where there is no air, so
combustion couldn't happen.

And this turned out to be crucial
for the development of electric

light. It was like a really
successful convergence of technologies,

at just the moment when electric
generators were reliable enough

to produce the electric inputs
for these lights, at the same time,

big vacuum pumps came on the
stream, that could suck all the

air out of bulbs and maintain
really, really low air pressure.

With this convergence of
technologies, it became possible to

think of having a light bulb with
a glowing filament in a vacuum.

But what should the filament be made of?

Now Swan knew that carbon, when
it is heated up, could be made to

glow very brightly, but what kind
of substance shall he carbonize?

He looked at paper, he looked
at a range of substances, but

then one day, he decided to
try carbonizing this: cotton.

So he would pack the cotton into this
container of charcoal. And seal it

and put it into an almost airtight
container, in the oven, and bake her.

After he baked it, he got this, the
first viable filament for electric light.

With this carbonized cotton
filament, he was able to make electric

light bulbs like this, shaped like
a lemon, and glowing bright red.

Swan's new bulb was a
technological triumph.

Joseph Swan's new incandescent
electric light was an instant heat with

the posh and the wealthy amongst
Victorian Britain's industrial class.

Now, one of Swan's best and closest friends
was sir William Armstrong, Mr. Tainsign.

Armstrong was an enormously wealthy and
ambitious Victorian entrepreneur. And Swans'

new invention was just the sort of thing
he needed to impress his wealthy customers,

they be brought to
Newcastle on Armstrong's

boats, they be greeted
by Armstrong's employees,

they would be taken up
to Armstrong's country

residents on one of his
own private railway trains.

Steaming up the hill
through the dark forests,

And what they found when they
arrived was this: Cragside.

Cragside was really Armstrong's
pride and joy. He turned it

into a kind of showcase for state
of the art modern technology.

It was described in the newspapers
as the palace of a modern magician.

This house became an electrified palace.

It was the very first
house to be lit by the

new fangled incandescent
electric light bulbs.

More than 40 of them delivering the

illumination of more
than a thousand candles.

Here is a wonderful example. This is an
incandescent electric light bulb, pretending

to be a gas lamp, pretending to be a candle,
pretending to be a medieval heraldic line.

It is a perfect image of the way in
which Armstrong and Swan's new electric

technology brilliantly
adapt itself to the

aristocratic values of
the late 19th century.

Yet there was a major
flaw in Swan's plan to use

Cragside to encourage
others to buy light bulbs.

To keep his house in
electric, William Armstrong

had one very big advantage. He had this.

He had his own river

which he used to run a big
hydroelectric scheme to supply

the electric power that kept
Cragside lit with electric light.

Now if Joseph Swan's scheme was going to
have any future at all, he couldn't possibly

rely on people like William Armstrong
with their own private electrical supply.

What was needed was a
public supply of electricity.

In the closing decades
of the 19th century, there

was really only one place
that was going to happen.

Swan had lit a house.
3000 miles away in New

Jersey, was a man who
wanted to light the world.

Thomas Alva Edison had also
just invented the incandescent

light bulb, but the parallel
with Swan stops right there.

Edison was in every way larger than life.
He was a kind of modern hero that no one had

ever seen before, a mixture of engineering
entrepreneur, businessman, and visionary.

In 1878, Edison set about building the
world's first public electricity supply.

He had to invent every single component
from the insulation surrounding the cables,

to the meters, fuses, switches, and above
all, the light fittings that made it work.

But that was just the
beginning. Making electric light

available is one thing, making
it economic is quite another.

The Edison revolution
had only just begun.

Perhaps the most important
problem that the Edison

system faced was that you
only need to turn the lights on

at the night, that meant
the electric light was only

gonna be used for a very
limited part of each 24 hours.

Now you can't easily
store electric power,

and it is really inefficient
and costly only to run an

electric system for a very
limited period of the night.

The answer was to
persuade a skeptical public

to buy more and more
devices which run on

electricity that would
make sure that they were

customers of the electric
companies on a 24/7 basis.

Edison's revolutionary
insight was that to sell

electricity, he needed
to sell a life style.

I want to tell you a bit
about the electric cooker.

So clean, so reliable
and so labor saving.

Well, I never.

Come on now, get us to sign up for
the thing Think of the husband's

little costume far less than all those
of the doctor��s bill of indigestion

it is not salesmanship, it
is just kindness to animals.

No stone was left unturned
to convince a skeptical

public that electric
lighting was the new future.

One electric light promoter, a man called
William Priest, went to bizarre length.

In my house, I use lamps
that required 30 volts

I often put the wires into the
mouth of my little children.

They don't much like it,
but it doesn't harm them

Well, I never. Well I
never. Is so that clean ever?

Edison's campaign to market
electricity and the electric light

bulb really set the tone for
consumer marketing ever since.

Because what Edison realized was
that he wasn't so much selling light

bulbs, he was selling dreams, dreams
of light, of leisure, of less work.

People were buying Edison's light
bulbs not so much because they needed

them, but because they had that
dream, that vision of a world of light.

And that technique that Edison
started with his sales campaigns

for electric light bulbs has
dominated marketing ever since.

It is been kept going,
whether you are selling

cars, or whether you
are marketing computers.

Today, light bulbs are everywhere.

They have become the symbol of a modern,
thrusting, 24 hour 7 day a week, society.

It is a world which has harnessed the
genius of Maxwell, with the brilliance

of Edison, to give us more control
over our environment than ever before,

or has it?

For many, it is an
encouraged world in which most

people may in reality have
less control than before.

Why is it exactly that
we live in a 24/7 society?

Is it because we really want to?

or is it, rather, because it
is the dictates of the machines

that they become profitable if
they are switched on all the time.

Is it that we live in a world
because we have chosen to live

in a world that is lit every
single day and every single night?

Or is it not rather the
demand for profit and

engineering that keeps the
world going, just as it does?

So, it looks as though these
technologies of artificial

light gave us unprecedented
control over the world around us,

but maybe, just maybe,

we are the victims, we are under the
control of machines and the market.

Yet for scientists, the real
impact of the light bulb had

nothing to do with control, in
fact, it has been very opposite

The light bulb was going to blow apart the
laws of physics and reveal the world that

is more uncertain, more unpredictable, and
more dangerous than its inventors dreamt of.

In the mid 1890's, in the town
of Wolfsburg, a German scientist

had embarked on a series of
new experiments with light,

his name was Wilhelm Rontgen,

and what interested
Rontgen was a new piece of

equipment recently developed
from the light bulb.

It was a vacuum tube,
a long glass tube from

which almost all the
air have been pumped out.

You couldn't make one
of these without the

technology which was being
used to make light bulbs.

The most extraordinary thing about
this was that if you pass an electric

current through the vacuum tube, it started
to glow, it started to glow brightly.

The tube was empty, yet
something was glowing.

It became known as a cathode ray.

Rontgen was intrigued, but
as he played around with

it, he came across something
even more extraordinary.

When he increased the charge,
and took a photograph of

a hand, he could suddenly see
the bones through the skin.

They became known as X-rays.

These X-rays made a sensation,
you could see through flash, cloth,

you could see embarrassing things,
perhaps, under people's clothing.

Anti X-ray devices was sold,

Lead pants to prevent your privates becoming
visible under this new kind of light.

There were cartoons about
X-rays, there were X-ray shops,

there was even the idea that X-rays was
some kind of spooky ray that came from your

eye, through objects, so that you could

penetrate them in some
kind of inexplicable way.

They were the news media
sensation of the 1890's

These mysterious rays of light
seemed to confirm for many people that

there was something beyond the
natural world, a super natural world.

cathode rays, X-rays, all sorts
of weird and strange radiations

went along with an explosion
of interest in spiritualism,

in fact, I think
spiritualism made more sense

in a world where there
were kinds of light,

and kinds of rays that
you couldn't see, but

showed you things that
were otherwise invisible.

After all, how do you
communicate with the dead,

by some kind of ray which
passes a barrier, which

otherwise seems impermeable.
Well, that is what X-rays do.

X-rays travel through glass
and flesh and they show

you things that otherwise
no human could ever see

In the decades to come, as scientists
pieced together what was really going

on, it became clear that X-rays have
nothing to do with the supernatural.

They are merely another part
of the electromagnetic spectrum.

At the top of that spectrum,
vibrating quite fast is blue and

violet light, and beyond it the
light we can't see, ultraviolet.

And now a form of radiation
emerges that is very high

frequency indeed, vibrating
extremely fast: X-radiation.

But the visible glow
in the vacuum tube would

lead scientists somewhere
very different, it

wouldn't help them
communicate with the dead, but

in its own way, it would
be just as revolutionary.

One of the centers of
research into the strange

characteristic of vacuum
tubes was Cambridge.

Here Maxwell's research lab was now
run by a physicist called J J Thomson.

It is one of Thomson's
misfortunes to have gone down in

history for an incident that is
almost absurd in its triviality.

In the 1920s, he is reputed to have
shouted at a couple of undergraduates

training for the 1924 Olympics in the
great court of the Trinity College.

One of them went on to win gold.

But Thomson, like Maxwell, was a brilliant
scientist and in the closing decades of 19th

century, he designed
his own cathode ray tube

to investigate this very
peculiar form of light.

This is a replica of
what Thomson designed.

What is special about it, is
that it allowed the cathode rays

to be effected simultaneously
by electric and magnetic forces.

And the experiment that
JJ Thomson did with this

tube would have the most
dramatic consequences.

Thomson was not a practical man,
in fact, he was notoriously clumsy.

Yet using his new tube, he performed a
series of hugely important experiments.

He would turn the cathode ray tube on,

You'd see, a glow, and a bright
point at the other end of the tube,

turn the electromagnets on,
the position of the dot moves.

The magnets are deflecting
the cathode rays.

Thomson repeated the
experiment time and time

again and measure the
size of the deflection.

Whatever was coming down the
tube was clearly not a wave,

it only made sense if it
was a stream of particles.

Thomson then plugged the figures
into Maxwell's famous equations,

and the result he got
was absolutely dramatic,

he found that the particles making
up cathode rays are tiny, much,

much smaller than atoms, and that
was an earth shattering result.

Nobody had ever produced
any evidence that

there was anything smaller
than an atom before,

Indeed, some scientist
didn't even believe in atoms.

Years later, Thomson was to
describe his findings in a

lecture to the prestigious
institute of electrical engineers

Today we know this tiny
particles as electrons,

This was really revolutionary stuff,

and what is so exciting about it was that
the technology to begin to pull atoms apart,

to begin to tell us story of the most
fundamental building blocks of the world,

came straight from light technology,
vacuum pumps, light bulbs, vacuum tubes,

It was by thinking about those bits of

machinery that the atom
began to be torn apart.

Yet it is one the history's great ironies
that at the time nobody realized science was

on the verge of a breakthrough, that will
turn physics and the world on their heads.

By the end of the 19th century,
most scientists in Europe and

overseas reckoned that in many
ways the task of physics was over,

the basic problems have been solved,
we knew how light, electricity,

and magnetism worked, we understood
the problem of heat and engineering.

Physics turned into a
search, not for great

new theories, but just
for better measurements.

One of these measurements concern
the production of light bulbs,

by now a hugely important and
influential commercial activity.

The light and power system
was the most important

financial area of
European world industry.

Getting the right answer
to problems of electric

light and electric power
meant big bucks worldwide.

The problem the industry faced
seemed scientifically trivial.

What they wanted was to get
the maximum amount of light out

of a bulb for the minimum amount
of electric energy going in.

so the physicists were asked do some
sum and calculate what the relationship

is between the amount of electric
energy heating up a piece of metal wire,

and the amount of light coming out
when that wire starts to radiate.

No one thought that this was gonna be a
deeply important theoretical problem, it

mattered to people's
bank balances, it didn't

seem to matter to
physical theory very much.

The man the industry turned to was
a German physicist called Max Planck

Planck looked at Maxwell's
celebrated equations, which

described the relationship
between light and energy.

It was then, that he had a shock.

What these equations suggested was
that the more energy you put in, and

the hotter the system got, the more
light and heat it should radiate.

Maxwell's equations have predicted that
the energy level will continue to build up

infinitely until an object was radiating
a catastrophic amount of light and heat.

And it would atomize.

But this simply isn't true.

Think about what
happens, for example, when

you have a metal bar
just resting on the fire,

as it starts to get hotter, it begins
to glow, initially just red, then all the

other frequencies begin to kick in, so it
goes from red through blue to white heat.

But no matter how hot it gets,
it is never going to explode.

This was a prediction from Maxwell's
theory that completely fail.

The apparently infallible
Maxwell had made a mistake,

It was a body blow to physics.

As Planck tried to untangle
what was going on here,

he came up with an idea
that was completely counter

intuitive. Now because Maxwell
though light was a wave,

Maxwell reckoned that when bodies
got hotter and hotter, there was

absolutely no reason why they
shouldn't emit more and more light.

Planck then came up
with a really cunning

scheme to trying make
the theory fit the data.

Planck's problem was similar
to the one Thomson had faced.

Thomson had to decide whether
cathode rays were waves or particles.

Planck faced an identical dilemma and
came up with an extraordinary solution.

What Max Planck was
saying, and for him, it was

a quit to any core fix,
was that sometimes light

seemed to be behaving
like a wave, but sometimes

it seemed to be behaving
a bit like a particle.

now after a bit, it quickly emerges,
that is a really revolutionary

idea, it completely undermines
the basis of modern physics.

Because light turns out to
have a split personality.

It has a wave nature on Mondays, Wednesdays,
and Fridays, as one of the physicists said,

and a particle nature on Tuesdays,
Thursdays, and Saturdays. Suddenly

young physicists had a big, new,
world shattering problem to work on.

And they stack their careers on trying
to understand light schizophrenia.

Everything in physics that had been
taken for granted was now up for

grabs, and every ambitious young
physicists wanted a piece of the action.

It turned into one of the most exciting and
creative periods in the history of science,

Quantum physics was born.

Planck's revolutionary
explanation of light forced a

fundamental rethink of the
basic properties of matter.

And what began to emerge was a
whole new world of tiny subatomic

particles no one until now
had ever imagined could exist.

To Thomson's discovery
of the electron were

added new particles,
like neutrons and protons.

This zoo of particles was just
impossible to pull together,

physicists for their meat and
drink, night and day, try to

work out a better story about
how these things could be pulled

together and the problem didn't
just stay inside physic labs.

No, physicists would write science
fiction stories, make movies

and plays, to trying get the
public interested, and they did.

The bubbling excitement
eventually resulted in a

completely different picture
of what the atom is like.

It is like a planetary system, there is
a central nucleus stuffed with neutrons

and protons, and around that nucleus
orbit the negatively charged electrons.

But what really mattered was that
this atom was bubbling with energy.

The atom itself could be an
inexhaustible source of power.

A new physics was born, a
physics of the atomic age.

Atomic physics gave us nuclear fission;

a terrifying new power was born.

Out of the ashes, emerges
a completely different,

completely new vision of
what light really is like,

and it is a very surprising one, because
it is a vision of uncertainty, not at all a

mechanical world in which effects follow
causes in a rigorous chain of consequences.

This is the world view of modern
quantum mechanics, a world view

in which light shifts its
character between wave and particle.

It has completely changed the
way we think about light, and

it has completely changed the
way we think about the world.

Ironically, the more we
uncover its mysteries,

the greater those mysteries have grown.

Next on light fantastic,
how light gave us trickery

of cinema and Einstein's
truth about the universe.