The history of light is the history of human cunning.
Ingenious humans have manipulated and turned light to build
optical tools of the most extraordinary sophistication.
Optical tools which could allow navigators to travel on earth and sea,
which could allow artists to make the most amazingly realistic pictures,
which could allow us to see the almost
infinitely distant and the unimaginably small.
These tools have had really surprising effects.
They've taken us deep into the heavens and reveal the very origin of the universe.
But as light told us more about God's creation,
it's forced us to face new and dangerous questions,
It's even made us ask whether God himself actually exists.
The journey to a new understanding of light begins here
in the Baltic sea around northern Europe in the 1500s.
And it begins not with scholars or scientists, but with traders and navigators.
In the 16th century, these waters were some
of the very busiest trade routes in the world.
Navigator's horizons had expended enormously to China, and Indies, and south America.
The trade goods that float through the
Baltic were amber and skins, wheat and timber.
And for that trade to flow, what was required was confident, expert navigation.
and the expertise of navigators relied on their understanding of light.
Baltic navigators built the best tools yet to gaze the stars. And
on this island, in their mist, lived an astrologer called Tyco Brahe.
He used scaled up versions of navigators' tools to
conduct an extraordinarily systematic study of the stars.
But Tyco was no ethereal scholar. He was tough and argumentative.
Tyco was a street fighting man. When he was a student, he
kept on ending up in brawls. One brawl was almost fatal.
The fight began when someone dare to challenge Tyco's astrological predictions.
In the ensuing duel, the bridge of his nose was sliced off.
Tyco was not abashed, what he did was to commission a metal replacement.
It was made of cooper, if it is like everyday
use, and then gold for ceremonial occasions.
Tyco's nose was of scar, he was proud to wear.
It was a sign that he wouldn't suffer fools.
There is his metal badge of his noble pugnacity.
Here, on Hven, Tyco wanted to make a better map of the heavens,
a map that would let him predict exactly the future of humans living on Earth.
Tyco took astrology very seriously.
He reckoned that there was the lights streaming down from the stars and
planets which allowed the heavens to control what happens here on Earth.
So Tyco made predictions of the weather, of the life and death of kings.
He flattered the king of Denmark, Frederick II, with these predictions,
and in return, the king gave him the entire island of Hven on
which to build an observatory, where Tyco could study the stars.
Tyco's observatory was state of the art.
He filled it with exquisitely engineered quadrels and clocks,
and used them to make the most accurate star charts to date.
Now all that is left are Tyco's most surprising
observational tools: the flower beds of his garden.
And the best way to see them is from above.
Tyco plotted it out to represent the signs of the
zodiac and help him map the positions of the stars.
It is just extraordinarily moving to be here, floating above Tyco's
observatory, looking down from the heavens with which he was obsessed.
The layout of the observatory is perfectly symmetrical, so there are two long
axis, one run in exactly north and south, the other exactly west and east,
with the big observatory building in the center, with large walls surrounding it,
And in between, a garden, a herb garden, an astrological garden in which
each medicinal herb was planted towards the point of the
astrological zodiac, which controlled the power of that herb.
Hyssop and balsam, roses and chrysanthemums.
The whole thing, reflecting the astronomical order that was going to be
revealed from this extraordinarily beautiful astronomical observatory.
And then, while out observing on 13th of November 1577, Tyco saw
something that would completely change the model of the universe.
There appeared in the skies above his head a comet, moving across the sky.
Tyco was transfixed by the sight.
Night after night, he tracked the comet with the
relentlessness of a hunter, taking meticulous measurements.
Tyco didn't know it yet, but this was dangerous data, data
that challenged the very nature of the universe created by God.
The church asserted as absolute truth that God
had put the Earth at the center of the universe,
and around it, embedded a series of vast crystal spheres,
He placed the Moon, the Sun, the planets, and ultimately the stars.
These spheres were impenetrable, and nothing could move through them.
Yet all these was about to be challenged by Tyco's comet.
Now, people knew that comets were moving in the heavens,
but if there were crystal spheres, the comets couldn't move through them, so
comets must be nearer to the Earth, nearer to the Earth even than the Moon is.
As the comet blazed across the sky, Tyco measured its movement so accurately
that it was possible for the first time to calculate its distance from the Earth.
The method Tyco used was based on a property of light called parallax,
it was a technique very common amongst navigators.
Imagine two boats out at the sea moving at the same speed,
one boat if it is further away will seem to
move much more slowly than the nearby boat will.
Well, if the comet is near the Earth, if it is moving between the Earth and the Moon,
then it should move fairly rapidly across the sky,
but that is not what Tyco saw
What he saw, was the comet moving really pretty
slowly against the background of the stars.
And that could only mean one thing:
the comet must be moving much further away than the Moon,
it must be moving in the area of the heavens which
people imagined was full of crystalline spheres.
Tyco checked his observations, the comet was
very far away. 6 times further than the Moon.
It was moving through celestial space.
Tyco's comet had completely overthrown the basic model of the universe.
If there were any crystal spheres, then the comet would have smashed through them.
Tyco have made observations of the most extraordinary precision,
and what they'd shown was that the church's
traditional view of the universe must be wrong.
There were no crystal spheres.
The distances of the stars, the planets, of comets were unimaginably vast.
All this brought a crisis in cosmology.
A new world view seemed to be required.
This wasn't just bad news for the church, ultimately, it was bad news for Tyco.
For this big beery aggressive Danish astronomer,
things in the end didn't work out too well.
He completely blew his relations with the Danish king
and he had to move away from his beloved observatory.
He died soon afterwards of a bladder infection
acquired after a particularly drunken feast.
But Tyco had made his mark. He was the first
person accurately to measure and map the stars.
And this work had put the claims of the church on shaky ground.
But that was nothing compared to what would happen next.
Glass would change everything.
When people began to stare at the heavens through this everyday
stuff, they would undermine hundreds of years of religious doctrine.
And it all began with a revolution in glass making in 16th century Venice.
Venetian glass was money glass.
It was a way of displaying the wealth of the great Venetian
merchants who dominated the trade routes from their watery city.
And it was gorgeous glass. From the 16th century, Venetians could
make Crystallo, a glass of unparalleled beauty and transparency.
And people noticed that glass has unique and magical properties.
Glass is strange and spooky stuff.
It makes light bend and change direction.
As it changes direction, it refracts.
Now people knew that well, they'd already started to use
lenses to make reading easier, to bring things into focus.
And the mastery of this extraordinary property of glass would
indeed change the way human beings could see the world around.
But in renaissance Venice, glass was seen as a decoration, a trinket, a toy.
So when in 1609, there was a rumor of a device for sale, a spy glass that
use lenses to make distant objects appear nearer, no one took it seriously,
except an impoverished math professor Galileo Galilei.
Galileo first got news of the spy glass which was roughly the summer of 1609,
he was extremely clever, very well informed and broke,
he wanted a much better job than the badly paying university job that he had,
and he knew, brilliantly, that if he could make a wonder, a marvel, a
new piece of technology that he could offer on the market or to a patron,
his name, his reputation, and his income would be made,
and this is what the news of the spy glass offered him.
But there was a problem, tricky bits of glass were usually sold by conman.
Charlatan is an Italian word. It means, or at least it
originally meant, the guys who got up on a platform in the middle
of the piazza and sold you snake oil, weird stuff, things to
cure syphilis, and things to make women fall in love with you.
And in between this charming, rather bizarre, but
definitely financial game, they showed you machines,
tricks, bits of glass, they showed you glass that make
things colored, it was called the science of miracles
What Galileo had to do was to exploit what the charmans was
doing and then make sure that no one mistook him for one.
Despite its tawdry reputation, Galileo was
convinced the spy glass could make him a fast ducket.
He realized that an instrument that could make distant
bodies appear very nearby could be much more than just a toy.
For a military and commercial power like Venice, it could be invaluable.
The Venetian navy could see its enemies hours before they arrived, and traders
could spot goods that were coming into port and adjust their price accordingly.
And of course, Galileo himself could racket in.
Galileo at once got hold of some good lenses from his local glassworks.
And he took them away to test, to play with.
The result of Galileo's games with these lenses would change astronomy forever.
Now, Galileo set about making a better spy glass than the existing one.
The spy glass showed things upside down, and it could only magnify 2 or 3 times.
But what Galileo did was to use a very
strong concave lens which he put near his eye,
and then at a determined distance further off, along the tube, a convex lens.
Now with that arrangement, Galileo's device could show things
the right way up and they showed them magnified 8 or 9 times.
Galileo's telescope was a technical marvel.
He was convinced he would make his fortune by selling it to the Venetian government.
But first, he had to convince them he wasn't a charlatan.
So he would bring skeptics up here to the top of the bell tower
in Venice, and showed them the familiar sights of the city.
And then he get them to look through the telescope, and
agree that he just did magnify and that it could be trusted.
What he was setting out to do was to get people to accept that light
traveling through a telescope was a reliable carrier of information.
Finally the Venetian government were persuaded that it wasn't just a
trick and they accepted Galileo's offer and rewarded him handsomely.
Galileo was extremely cunning in dealing with the Venetian government,
in exchange for offering them a monopoly over the manufacture
of his new spy glasses, he wanted a serious salary increase.
And he got it. Unfortunately, the very next day,
he was found out that government discovered that spy
glasses sold by charlatans in the markets of Venice.
They are not as good, were a lot cheaper than Galileo's,
and they refused to increase his salary ever again.
But now Galileo had what he needed, some money, and more
importantly, a tool to manipulate light: the telescope.
Here, the balcony of his house, Galileo turned
his telescope to the skies for the first time,
What he saw amazed him. He saw a world that
people had never dreamt could possibly exist.
Over the next few months, he became obsessed
by what he could see on the surface of the Moon,
it was rugged, it had craters and mountains, he even
managed to measure the height of some of the mountains.
They were 4 mils high.
He saw far more stars than you can see with the naked eye.
Nobody had ever seen these things before, the telescope revealed a
universe far bigger and more complex than anyone had ever imagined.
Galileo worked hard to publish his findings just as soon as he could.
He quickly released a book called the Starry Messenger.
Now the book was an absolute revelation. Although the public
read it avidly, they found it disturbing and confusing.
It showed hundreds of stars invisible to the naked eye.
It showed mountains on the Moon, carters and seas.
It showed stars never before imagined.
The whole universes seemed to be in flux, and all these because of a simple telescope.
But hidden in the Starry Messenger was the
most explosive of all Galileo's observations.
These tiny sketches would ignite one of the greatest
controversies in the history of the Christian church.
They refer to the observations he started on the 10th of June
1610, the night he trained his telescope on the planet Jupiter.
He saw 3, and then 4 moons orbiting round the planet.
This would shake the world view that it held sway for 500 years.
Throughout the ages, people had considered themselves to be special,
to hold a pivotal position on Earth
After all, the book of genesis said that God made man in his
own image, and place him on Earth at the center of universe.
It was believed that all the planets were rotating
round the Earth, and this even included the Sun.
But Galileo's telescope-suggested things were very different.
What Galileo had shown with his discovery of the moons orbiting around Jupiter was that:
here were bodies orbiting round somewhere else, around another planet.
And that made it much more plausible that there were many objects
in motion in the universe, each revolving around different centers.
Above all, I think, it made it really plausible that
the Earth was moving, that the Earth was a planet.
Galileo's work was evidence for a startling new
model of the universe with the Sun at the center.
Now, the Earth might be just another planet orbiting round the Sun.
Suddenly, the church's creationist model of the universe was in big trouble.
Men had lost his special divinely appointed position at the center of everything.
The position of the church as all knowing, and all powerful was under threat.
Yet the last thing Galileo had intended was to damage the church.
Galileo was a religious man, who simply wanted
the church to get it right, and not look foolish.
And he openly said the bible who may tell you how to
get to heaven, but it doesn't you how the heavens go.
By mastering the telescope, Galileo had revealed how the heavens go.
Galileo had made his telescope just to make money.
Yet unwittingly, using light, he dealt a damaging blow to God's supremacy.
After the success of Galileo's telescope, the lens's market boomed.
Lenses become an almost universal technology and reached into every aspect of life.
Art would also be affected by the combination of light and lenses.
A dramatic change would take place in ways of painting, and drawing,
and a new kind of realism would enter the way of representing the world.
For the first time, the ordinary, the everyday
became subjects for the artist's canvas.
And all that happened through a set up called the Camera Obscura.
with the light from the subject passes through a
lens, so it is projected into the painter's canvas.
Philip Steadman is an expert on the camera obscura.
What we got here is that I am in the camera obscura, of this half
of the studio that I am sitting in is pretty much in the dark,
and between you in the middle is the lens, you are very brightly lit and the
image comes through the lens onto this translucent screen that I am working it,
I am tracing around the other side of it.
Obviously, one of the things about the images
is that I am upside down. Why am I upside down?
Well, you are upside down because we got
very simple camera arrangement here. Just the
lens between you and me and the screen, and the rays of lights, cross over in the lens,
and so the, as well the bottom half of you becomes the top half of the picture.
So the lens focuses the rays of light coming from me straight on to the
canvas. It is the same principal and the basis of modern film cameras.
Artists started to become interested in camera
obscura with lenses in the middle 17th century.
The outstanding example is Vermeer.
Vermeer seems to have become interested in
the camera obscura in the middle of his career.
There is a definite date when he changes completely.
And you really can see the difference that using a lens makes to Vermeer's work.
the 3 characters in the first painting have heads of the same
size despite the fact there were very different distances from us.
But the perspective in the second painting is exact and photographic,
the soldier's head is twice the size of the girl's cause he is much closer.
But it is not just the perspective that's
changed. Vermeer was moved from painting mythical
religious scenes of angels and icons to
portraying the real world of soldiers and servants.
So here is the finished product.
Oh well done, that is magnificent.
I think it does more than justice to the sitter.
You are very kind. It is of course done extremely
quickly. Yeah. I mean, this is only half done of its work.
The use of lenses had created a new art of describing the world.
What lens technology and the camera obscura meant was that artists set
out to make realistic images of the world as they saw it around them.
The telescope had completely changed people's relationship
with the world, of the great, and of the small.
And now, the camera obscura had put people into perspective, giving
them an account of the world that was realistic, that was accurate.
In 17th century Europe, lenses were used to explore every aspect of the world,
not just up into the heaves, but down towards the Earth.
London in the 1660s was booming. It was the commercial headquarters of the world.
Here and now was the birthplace of capitalism.
As the British empire was expanding through
trade, scholars were also exploring new worlds.
It was fashionable to be curious, and no one was more curious than Robert Hooke.
He was the engineer who designed London street after the fire
of 1666, and the man who will lead the next revolution in light.
The brilliant, if slightly warped, Hooke was constantly experimenting, often on himself.
I have drunk lead, which somewhat benumbed my head.
To cure of vertigo, I let my blood 7 ounces. The vertigo continued,
but upon snuffing ginger, I was much relieved
by blowing out my nose a lump of thick jelly,
and to treat the stomach, I have
experimented with volatile spirit of wormwood,
which made me very sick and disturb me all the night and purged me in the morning.
This is certainly a great discovery in physic.
Hooke was intensively inquisitive about how everything worked.
Anatomy, engineering, philosophy, everything was greased to Robert Hooke's meal.
Hooke's greatest passion was light,
and he had exactly the right tools and skills to make the most
of this passion because Hooke was also a master of glass working.
He had really skilled allies in the London glass trade.
And these men were capable of making the very finest lenses.
But Hooke's genius was to turn the same technique which had
worked in telescopic astronomy towards designing microscopes.
Because the same principle of magnification would work, not
just on the very large and distant, but on the very small.
What Hooke saw through the lenses of his microscope was an absolute revelation.
For the first time, he was unlocking the machinery of creation.
Here was a world of beauty and of terror, insects
that looked like aliens, hideous monsters in miniature,
nothing was as it seemed.
Hooke recorded every minute detail with exquisite drawings.
And in 1665, he published the extraordinary book: Micrographia.
When Samuel Pepys got his copy, he stayed up until 2 in the morning, engrossed by it,
and called it the most ingenious book that ever I read in my life.
Hooke's microscopic world was wonderful, but it was also extremely threatening,
because what it meant was that the Earth had opened at the feet of Hooke's readers.
They saw beneath them in an unimaginable, and otherwise
invisible world. Something minute but of immense complexity.
Agents, beings, and structures they had never dreamt of before were there.
All around them, inside their bodies, in their hair, under their skin.
A world of life and structure which they didn't
understand, whose purposes was not obvious.
After these great successes, Robert Hooke eventually died of the
damage caused to his body by his obsessive self experimenting.
And his legacy was also disturbing.
People were troubled by the micro world Hooke
unveiled cause they no longer seemed unique or special.
They began to question whether they have been
chosen by God, and whether there was a God at all.
Robert Hooke's work with microscope completely
changed the boundaries of natural history.
In fact, in the 18th century, naturalists became rather a craze throughout Europe.
People began collecting specimens of animals, vegetables, and plants,
to try work out what species they were, and how they could be classified.
In the 1700s, classification was one of the hottest words
of the day, and the hottest place to discuss it was Bath.
Bath was the Las Vegas of the 18th century,
it was rich, it was boomtown. It was slightly seedy.
Not only did the eel come here, but the intellectuals as
well. They gossiped in the coffeehouse and around the spa.
They shared ideas about life, the universe, and everything.
Among the clever gents was William Herschel. A
musician from Germany who came to Bath to play here.
Herschel would transform the understanding of
light more dramatically than anyone before him.
As he mixed with Bath's philosophers in salon, he
rapidly got drawn into the classification debate.
Herschel made his name in Bath intellectual society by studying this: coral.
The big problem was: is this animal, or vegetable?
Herschel got hold of a microscope and began to study coral very closely.
Herschel applied light and lenses to the problem.
And what he saw were thin cell walls, this could mean only one thing:
Coral, which previously been thought to be a plant, was in fact, an animal.
Herschel made a huge leap of imagination,
if this approach with light and lenses work for things
on Earth, maybe it will also work for the heavens.
Herschel will treat the stars the way living species are treated.
He decided to classify them.
What you needed to do that, Herschel reckoned,
was huge telescopes which by penetrating deeply
into space would be able to classify what kinds
of things stars, nebulae, and galaxies really were.
He would become the first natural historian of the heavens.
But there was a problem with building huge telescopes.
Since Galileo's spy glasses, people have built longer and longer telescopes,
which proved almost impossible to manage, and possess
lenses which could never bring the image into perfect focus.
Herschel had a different idea.
He realized he could apply one of Newton's
cleverest ideas and replace lenses with mirrors.
A curved mirror magnifies rather the way a lens does,
but most importantly, mirrors grasp much more star light than any comparable lens.
Trouble was: no one had ever made mirrors this big before,
they would have to be curved with exquisite precision to focus the light.
So Herschel took matters into his own hands,
he turned his kitchen into a factory to make mirrors,
and would spend up to 16 hours a day painstakingly polishing them
to get them to just the right curved shape to focus the light.
He was obsessive about this and became the world's best maker of mirrors.
Once he perfected his mirrors, he put them to use inside his telescopes.
Herschel dreamt up a cunning scheme to allow you to see the mirrors' image.
Light entering the telescope will reflect off a big
curved mirror onto a smaller mirror set at an angle.
Looking into the second mirror allows you to see
the brightly illuminated image without blocking it.
With this new telescope, Herschel soon made an amazing discovery.
On the 13th of March 1781, he saw, what he thought at first was a new comet, but very
soon, it emerged that it was a new planet,
that first ever discovered in recorded history.
As an attempt to get patronage out of king George III, Herschel
and his friends decided to name this object George's star,
but no one else decided to call it that, so it is known to us as Uranus.
It was an extraordinary triumph for Herschel's astronomy.
Simply by finding this planet, Herschel had doubled the size of the known universe.
King George rewarded Herschel with a life pension and a house in Slough,
making him by far the most successful amateur astronomer in history.
But Herschel's next discoveries would be even greater, even grander,
and they'd hinge upon a fundamental property of light, its speed.
The question of whether light takes any time at all to travel
was an ancient one. It had been discussed by the Greeks.
But it is a major puzzle. It doesn't seem at all
obvious that light does take any time to travel.
When I look at some really distant object
like that tree. To look it is to see it, it's
as though light is instantly switched from there to here, from the object to my eye.
So that was a fascinating, a really urgent puzzle.
Was there a way of working out whether light does take any time to travel?
You couldn't hold it in your hand and measure its speed.
The answer lay in the motions of the solar
system, and in particular, the motions of the
moons round Jupiter. Just those moons that
Galileo had first observed with his telescope.
Now in 1676, a brilliant young Danish astronomer,
here on Earth, Ole Roemer, was observing
the moons of Jupiter because he wanted to measure
the times they took to go round their planet.
And he spotted something very surprising.
The time he was measuring depended on the distance between the Earth and Jupiter.
When the Earth, as it orbits, was nearer Jupiter, he seemed
to be seeing the moon going round Jupiter rather quickly.
And when it was further away, he seems to see
the moon going round Jupiter rather more slowly.
And Roemer could explain the difference,
it is due to the time it takes for light to travel from Jupiter to the
Earth. Light does take time to travel and you can measure its speed.
Roemer calculated a figure and got astonishingly
close to the real speed of 300,000 kilometers a second.
The realization that light actually does take time to travel and the
exact measurement of the speed of light were the most amazing discoveries.
It was a building block for an entirely new kind of physics.
William Herschel was cunning enough and intelligent enough to realize
just what the finite speed of light meant for him and his work.
when you look at the Sun, you are not seeing the
Sun as it is now, but as it was about 8 minutes ago.
Because it takes light about 8 minutes to reach us from the Sun.
but Herschel's telescopes allowed him to see much further away than that.
To galaxies unimaginably distant, and when Herschel did the calculations,
he realized that light must have taken millions of years
to reach his reflectors from those distant galaxies.
So Herschel's telescopes were like time machines.
They were devices that allowed him to travel
backwards in time to the immense vastnesses of space.
The implications of Herschel's discoveries were genuinely shattering.
and they were going to turn him into a world famous celebrity.
Actors took to the stage in London's west end to tell
an enthralled public about William Herschel's findings.
The honorable William Herschel has looked further into the heaven than any man before,
and what he has found
is most remarkable.
It might seem extraordinary to us that William Herschel's
astronomy became a theatrical event, but that is just what happened.
People flood to west the end in droves to theaters like this to
be shown what it was that Herschel was saying about the universe.
And it made him an immediate star, a
personality, the most famous astronomer in Europe.
Having seen so many stars through his excellent telescopes,
Mr. Herschel has charted the entire Milky
Way, enlarging the universe, many times over.
Now traditionally, the world had been understood as limited to the solar system.
But for Herschel, the solar system was just
one of many systems inside of vast Milky Way.
The size of the universe had been expanded enormously.
Herschel realized what is he looked through a vastly sized universe,
he was also looking through a vastly old universe.
Mr. Herschel has observed stars whose light, it can be
proved, must take 2 million years to reach the Earth.
And these 2 discoveries, the great size and age of
the universe let Herschel to his biggest idea of all.
He believes, that just as befits a dog, or a tree, a star must be born, grow and die.
Not only did Herschel believed that the universe was enormous and bounded,
But he also believed what is even more dramatic. There was in many ways, a life.
As you looked through his telescope, out into
the space, you were like a botanist, a naturalist,
looking backwards over the whole life cycle
of an immensely old, an unimaginably old plant.
So as he looked through his telescopes, back in time,
he could see the universe and its contents in various stages of development.
The occupants of the universe, the stars, the nebulae, and
the planets themselves have life cycles just like animals.
They would come into being and pass away.
And the key, he thought, to these life cycles of the stars was light itself.
He has determined stars in the furtherment, grow from light.
It seems to me that in many ways, Herschel's ideas must have
struck a lot of his contemporaries as absolutely appalling.
Not just revolutionary, because what this meant was, that the
Earth become a completely trivial occupant of the universe.
It wasn't of course, the center of the solar system,
but the solar system was just a minor star in the western spiral arm of the Milky Way.
And within the milky way, within the universe, there were
unaccountably many nebulae, each of them vast numbers of stars.
This was a sublime idea, but dangerous, and threatening,
because it undermine the uniqueness of humanity.
It made the universe, perhaps, a larger and older, but
also in a way more threatening place for human to live.
William Herschel had shown that the universe is very
big, and very old, and it is constantly evolving.
Now that was shocking enough to many people, but worse was to come.
What Herschel had said was that clouds of light evolving
to stars, and then suns, and then our Sun, our planet.
This idea of constant gradual change had an enormous and unanticipated impact.
It directly inspired a young naturalist called Charles Darwin to
come up with the most dangerous scientific idea of all: evolution.
In the early decades of the 19th century, evolution became thinkable.
It became possible to imagine that there was a
natural law like story telling how the great diversity
of life had emerged on our planet without
creation, without miracles, effectively without God.
And in 1859, Charles Darwin printed this book:
On the origins of species by natural selection.
The boldest attempt yet to replace creationism
with something more natural and law like.
Now there were those who were seduced by
those idea, but most found this book obscene,
as though the wonders of creation, and above all, humanity itself were a kind of random
throw of the dice that they emerged by the
law of higoudi pigoudi. This was intolerable.
The war over evolution began.
Victorian physicists and engineers got theory men all
of them couldn't stand Darwin's anti-creationist theory.
And they had a good way of proving him wrong.
Light, sunlight, was at the heart of the battle.
Darwin's theory of evolution needed hundreds
of millions of years in order for it to work,
and the greatest British physicists Lord Calvin
simply wasn't prepared to give him enough time.
Calvin believed that physics proved creation, and his reasoning
was based on the Sun, that extraordinary source of energy and light.
Scientists had realized that of all the things
necessary for life, light was the most crucial.
Sunlight powers all life by fueling the growth of
plants, it creates foods for all other animals to feed of.
But imagine, as Lord Calvin did,
that the Sun was made of the very best fuel you could get at the time, something
like good old British coal condensing under gravity, how long could such a Sun burn?
Now if you do the sums that Calvin did, you quickly find out that
the Sun could only of be burning for a few tens of millions of years,
There just wasn't enough time. This great big British physicist was saying
for the processes of evolution to work the way Darwin said they would.
That was just fine for Calvin. He was a creationist, he
thought the world was rational, orderly and designed by God.
His physics and his religion fitted together nicely.
Sunlight had given round one to the creationists,
and Darwin died with no comeback to Calvin's argument.
It seemed that evolution, this incredibly elegant
and revolutionary idea might remain just that,
an idea.
A man in 1904, a brilliant young New Zealand physicist turned up in London to give a
big lecture at the royal institution on a
major new discovery he had made: Radioactivity.
Calvin was there. He was dozing a bit in the audience,
but he woke up when Rutherford started to speak.
Because what Rutherford was saying was that here in radioactivity was a new
kind of energy which could keep the Sun going for thousands of millions of years.
More than enough time for the processes that Darwin needed.
Physics paid off for the evolutionists. By the middle
of 20th century, nuclear physics could explain how stars,
in their cores were fusing, generating enormous
amounts of energy which reaches us as starlight.
The answer to evolution's time scale was the nuclear physics of starlight.
Light had won the case for evolution.
Evolution shifted from being merely a possible story about the
emergence and history of life to becoming probable, authoritative.
Light provided the evidence for a history of
the world that required no God and no miracles.
For the first time, there was a powerful and effective
alternative account of how the world and life emerged.
Now, light can take us back in time through
billions of years to the origin of the universe.
The Hubble space telescope is the most powerful telescope we have.
Inside it is a giant mirror, 2.4 meters wide,
of which Herschel himself would have be proud.
Scientists have just used it to reveal something
truly astonishing: the oldest starlight in the sky.
These latest photographs from Hubble showed
galaxies and stars over 13 billion years old.
Stars born just after the big bang.
Finally we can look back in time and see the origin of the universe.
Scientists have used light as a tool to reveal
the scientific story of the beginning of our world.
We used to think that the universe was incomprehensible,
miraculous, the result of an act of God.
But by the manipulation of light with
instruments, the monuments of human ingenuity,
we have completely changed our model of the world.
Galileo's telescopes, Robert Hooke's microscopes, William Herschel's vast mirrors
made the universe a place which could be explained,
a place which could be understood, using the light of reason.
Next, on light fantastic, the journey from the light bulb to the nuclear bomb.
How the quest to understand what light really is has given us the modern world.