Breakthrough: The Ideas That Changed the World

Since the dawn of humankind,

we have looked to the stars and wondered,

what's up there?

What lies beyond this small, blue planet we call home?

"If only," our ancestors thought,

"there was a way to bring the sky closer

to really see the stars."

Just how humanity managed to do this is quite a tale.

It would take crystals forged inside the earth...

Just the right amount of salt,

a chance alignment of two small pieces of glass,

a property boom in New York,

and an accident of chemistry and light

to create the device that would open our eyes

to the universe itself...

The telescope.

These are the inventions that define our age

and changed our world forever.

They have allowed us to move on the ground

and in the air,

to connect with each other,

and make machines in our own image...

Each a story of ingenuity, of wonder, of breakthrough.

Today, we are on the brink of a new revolution.

Giant new telescopes are being built all over the world,

which scientists hope will answer some of the oldest

and most profound questions humans have ever asked...

How big is the universe?

Are we alone?

Do the stars go on forever?

This is a really fantastic time to be an astronomer,

helping us build the picture of understanding

about the universe that was completely unimaginable even 100 years ago.

Around the world, a new generation of telescopes

is pushing the limits of our vision ever deeper into the cosmos,

and the Hubble space telescope is still at the forefront of this effort.

Astronomers here at the space telescope science institute

are combining images from Hubble with other telescopes

to stretch our vision as far as possible.

We're looking for the most distant galaxies

that we can find in the universe.

There's entire systems and worlds out there

that, you know, I'm seeing for the first time.

The story of the telescope

is inseparable from who we are.

It took over 13 billion years to get to this point

where we could build telescopes in space

and witness our origins.

These gleaming technological miracles

of glass and steel define our age.

But the telescope's origin is stranger than you would imagine.

It would all begin with a pile of rocks in Southern Europe.

6,000 years ago, the stone age people

living in this part of Portugal

built these stone structures.

For the last 10 years,

I've been studying these ancient sites

around the countryside where I grew up.

And I believe these megaliths were one of

our earliest attempts to study the stars.

But why were the stars so important to these ancient people?

Because the stone age communities living here

were hunter gatherers and Shepherds.

They were living off the land, which isn't always easy.

That's why in the summer

they would go into the mountain ranges that were green

and provided enough pasture for their animals and for themselves.

And the best way to know when it was time

to move to the mountains was to look to the stars.

So how did these megaliths help them in this quest?

In a perfectly dark night sky,

the human eye can see around 5,000 stars.

To look beyond and see things that we wouldn't normally see,

we need the telescope.

And I think that such technology was already present 6,000 years ago,

1,000 years before Stonehenge

and about 1,500 years before the pyramids in Egypt.

And we also find the remains of it here in Portugal

in the shape of these stone monuments or dolmens.

They only had stone tools, wooden tools,

and possibly bone tools.

And yet, somehow they managed

to carve these rocks out of the landscape,

drag them a few miles, and put them in place.

This was clearly a project

of huge significance for these communities,

and they didn't just do it once.

There are between 15 and 20 monuments

in this river valley alone

with the same orientation, towards the east.

I think these rock chambers were used

to accustom their eyes to the dark,

allowing them to see fainter stars.

Using computer software, we can reconstruct the skies 6,000 years ago,

as it would have been seen from inside these stone monuments.

In the course of a year, as we orbit the sun,

as seen from the earth,

the sun appears to pass through

different parts of the sky.

In the spring, a star called Aldebaran begins

to appear close to the sun as it rises in the east,

marking the perfect time of the year

to move to higher pasture.

The problem is that Aldebaran is all but obscured

by the glare of the rising sun,

which makes it hard to see.

But I think these dolmen,

with their large chambers and long, stone tunnel,

would have allowed them to focus their eyes on a smaller patch of sky

to see the star at sunrise

sooner than they would by standing outside,

signaling to move to the mountains for the summer.

These structures Mark the moment in human history

when we realized that the skies ran predictably like clockwork,

and if you could see the stars better

and, therefore, decipher the patterns in the night sky,

it could help you to survive.

Across the world there are many other

stone structures from this time

which also appear to be aligned with the heavens.

It seems that as soon as we could deploy technology,

even stone technology, we applied it to the stars.

To me, this potentially represents humanity's first steps

into this journey of discovering their place in the cosmos.

Across the world, our ancestors were exploring the heavens.

From Egypt to Australia, early human civilizations

were driving a revolution in human vision,

stretching our sight further out into the cosmos

than the naked eye alone could achieve.

But the telescope requires one material above all others...

Glass.

And the first glass would come from the earth itself.

Over 5,000 years ago,

the people of Rifeh and El Badari in central Egypt

started to pick up small pieces of glassy quartz crystal

that caught their eye, and this is one of them.

Around the world, people were finding

naturally-occurring crystal fragments like this

that appeared to distort the light.

No one knows for sure what they might have been used for,

perhaps as a tool of some kind or simply as jewelry

or some kind of decoration.

But they all have one thing in common...

They could control light.

How they were doing this remained a mystery,

one that would only be solved by someone living

in an extraordinary place at an extraordinary time.

Baghdad in the 9th century really was one of the greatest

and most amazing cities in history...

Perfectly round, 4 miles in circumference with 4 gates,

each at right angles to the other.

Clearly the people who live here just loved math and loved using math.

Baghdad in this period was like Florence during the renaissance

or silicon valley in the age of the Internet.

We often talk about this mythical place, the house of wisdom.

Some would say it was a library

or it was a translation house

that brought together the knowledge of the Greeks,

the knowledge of the Persians,

the knowledge of the Indians,

all converging on this one spot in Baghdad

in the house of wisdom,

a cross fertilization of ideas

that hadn't really happened anytime before that in history.

One of the greatest of scholars of the medieval time

was Ibn Al-Haytham, who was curious about the world.

Ancient Greeks couldn't agree on the nature of light,

on how we see.

Some thought it was light entering our eyes,

some thought it was light beamed out from our eyes.

In a ground-breaking experiment

that would prove which it is, Ibn Al-Haytham blocked a window,

leaving a tiny hole

to create what's known today

as a pinhole camera or camera obscura.

A faint view of the street outside

materialized on the wall opposite,

proving that the light was entering the room from the street,

rather than being projected from his eyes.

But there was a second revelation...

The image was upside down.

Ibn Al-Haytham realized this must be

because the light from outside was traveling

in straight lines as it entered the room.

In fact, all light bounces off objects

in all directions in straight lines.

And once you know that,

you can start to manipulate light

and use it to reveal things that were previously hidden.

Light travels in straight lines.

A phrase that would be translated into

other languages all around the world.

Ibn Al-Haytham's theories are documented

in his celebrated "book of optics,"

written almost exactly 1,000 years ago in the early 11th century.

Its pages contain profound ideas about the nature of light,

and they explain why those crystal lenses

distort the light as they do.

For me, Ibn Al-Haytham is the most significant physicist of his age.

His accurate modeling of the nature of light