The Universe

[ Thunder rumbles I

stonehenge, one of the world's oldest structures.

Its foundations predate the great pyramids.

/t is one of mankind's most ancient mysteries.

Why is it here? Is it a temple?

A burial ground?

A place for sacrifice?

Or, could the mystery of stonehenge be revealed in its builders' desire...

Fo explore the unknown heavens...

And touch the universe?

Using the cutting edge computer-generated imagery that takes us info deep space...

We'll also go inside a virtual stonehenge...

Fo see what the ancients saw.

And push this prehistoric marvel fo give up its age-old secrefs.

Ancient mysteries, shrouded in the shadows of time.

Now, can they finally be solved by looking fo the heavens?

The truth is up there, hidden among the stars...

In a place we call...

The universe.

The mysterious circle of sfones called stonehenge...

Sits on a Southern english plain...

Inside an earthen bank 5,000 years old.

It was built over 15 centuries...

Begun by stone age farmers and herders...

Later completed by groups of successor peoples...

With sophisticated engineering skills.

What drove them fo build it?

What is stonehenge? People have said that it's a giant temple...

A wonderful monument sitting out in the Salisbury plain...

Where thousands of people could have come thousands of years ago.

To worship what? Gods?

We have no written records.

We take what we can from what we see...

And attempt to find out what it is.

[ Narrator I what we see are the ruins of what was once a complex array.

Could this structure made of earthly rock...

Actually have been devoted fo what lakes place in the sky?

Watching the bright sun come up every day...

The moon come up and change its shape throughout the weeks and the months...

Must have been quite a show.

Was this the hubble telescope of its time?

The first clue fo the mystery may come from the sun.

&&' [ Rhythmic I

every June, huge crowds gather at stonehenge...

In a strange dawn ritual.

It's the first day of summer-

the solstice- longest day of the year.

The people stare intently at a giant Boulder...

Called the heelstone.

What is remarkable about the construction of stonehenge...

Is that on the first day of summer...

If you stand at the center of the monument and orient yourself towards the heelstone...

Then as the sun rises, you'll see, essentially, the sun come up just over the heelstone.

The precision to which this occurs, year after year, seems miraculous.

Is it just a coincidence?

Or did the ancient builders put the monstrous heelstone in just the right place...

to Mark this day's sunrise every year?

It's outside of the ring. It's over 200 feet outside of the ring.

It is 16 feet tall.

It's probably got another four feet in the ground just to keep it stable.

And it weighs 35 tons.

Was stonehenge a sun temple with its focus at the heelstone?

Do other stones point to the sun as well?

The ruined monument we see foday is incomplete.

So the answers may lie in just how the giant stones were originally arranged.

The main ring was a series of vertical slabs topped with heavy cross pieces.

These lintels as well as the uprights, were made of sarsen stone...

A type of sandstone common to the area.

The sarsen circle is 180 feet across.

Thirty stones. Average weight can be anywhere between 20 and 40 tons.

This is as large as a fully-loaded cement truck.

This construction task boggles the mind even today.

[ Narrator I inside the sarsen ring was a horseshoe arrangement...

Of heavy stone arches...

Each piece weighing up fo 50 fons.

They're known by a deceptively forbidding name-

the trilithons.

Trilithon just means “three stones.”

Three stones in this configuration.

So two giant stones have been stuck into the ground...

With another giant stone then carefully placed on top.

To work out the link between the stones and the sun's changing path through the sky...

You would need to visit stonehenge every day for a year.

And place cameras in dozens of locations.

But now there's a better way to look at stonehenge from every angle-

through the power of state-of-the-art computer graphics.

So in the simulation we're present-day summer solstice sunrise-

we're camming out, coming up over the monument...

Taking a look at its present state...

Advancing the sun as well.

Shadows come across the surface, and it looks beautiful.

Professor John fillwalk heads up idia lab...

At Indiana's ball state university.

It was started as part of a $40 million project...

Lo use computers fo visualize what our eyes cannot.

Massive processing power immerses us in the ancient monument...

Lo decipher the mysteries of the silent stones.

Come into the sarsen ring.

Then we can take a look at the trilithon in the back, the main one.

Thread the needle there. [ Whooshes I

maybe spin around so we can see the features out there.

Using exact measurements of the stones taken by archaeologists...

The computers camera can move around a precisely-reconstructed virtual stonehenge.

The simulation is as accurate as can be. We have an accurate model.

It's positioned accurately, and the data is also accurate.

So, what you're observing is precise.

Astronomical data compiled by NASA...

Aaas the positions of everything in the sky, seen from the stones...

Just as if you were standing there.

And by typing in a date and time of day...

We board an electronic time machine...

That carries us fo any moment in the past, present or future.

Waftching the sunrise position change from month to month is effortless.

At this point, let's advance one month and see what happens.

You can see the sun, roughly framed by the sarsens there.

If we place the computer's camera in the center of stonehenge...

One thing becomes immediately clear.

Your eyes are drawn fo the horizon.

Modern man pays little attention fo the horizon.

In our cities, it all but disappears.

But for ancient astronomers tracking the sun...

The horizon was a key reference point.

If you want to do astronomy simply...

It's really hard to find things in the middle of the sky-

to accurately locate them when they're directly overhead.

But the horizon's a great place to try and get an accurate measurement...

Of how things are changing on the sky.

Ancient astronomers could see that the sun rises and sets...

At different places on the horizon during the year.

Because the earth's axis is tilted...

The northern hemisphere leans away from the sun in winter...

Making the sunrise seen from stonehenge farther south.

In the summer, the tilt is toward the sun...

Making the sunrise farther north.

When it rises on the first day of summer...

The sun is as far north as it ever gets.

Its position, in fact, may have been so important at stonehenge...

The central axis of the entire site points directly at it.

But other stones Mark the sun foo.

Take, for instance, the massive trilithons.

Each one of those appears to be a sight...

For an event on the horizon.

So, for example, I can turn to one of the trilithons...

On the sunset of the first day of summer...

And watch the sun set right through the middle.

And the sunlight will come through like a dagger right into the heart of the monument...

Right to where I'm standing.

[ Narrator I but the summer sunrise over the heelstone...

Has always seemed the most important marker.

It's in line with the ceremonial approach called the Avenue.

The crowds face northeast...

Looking down the Avenue fo witness the event each year.

But new evidence now suggests that the true main event at stonehenge...

Plays out in a totally different direction...

In a completely different month.

For thousands of years, the monument we know as stonehenge...

Has defied definition.

But today, many believe it was an early astronomers site.

Was this a prehistoric observatory with a spiritual connection...

Lo the cycles of the universe?

Exactly what was it its builders saw?

The annual arrival of the crowds...

Celebrating sunrise on the northeast on summer's first day...

Support the notion that this was the main event here.

But new evidence turns this theory upside down.

It suggests that astronomer priests conaucted their most sacred rites...

In the other direction.

A high-tech laser scan in 2011...

Revealed something totally new about the main sarsen circle.

The sarsens seem to have been very, very carefully worked...

To look their most beautiful on that approach from the northeast...

And as you go into the monument.

Not looking from the other direction.

But what happens as we do look in that other direction?

The sun is behind us.

The stones cast thelr shadows ahead.

Were the stonehenge builders sun-worshippers...

Who warned us, 'look away from the powerful god”?

Or could it be the crowd is not only facing the wrong way...

They are here on the wrong day.

Happy solstice!

If we spin forward in time...

Half a year of sunrises and sunsets have gone by.

And we reach the moment when the sun, again, appears directly in front of us.

It happens in December, on the first day of winter...

When we see, not the sunrise, but the sunset

only one leg of the largest trilithon still stands.

But in antiquity, it fully framed the breathlaking event.

Was the brilliant winter sunset an object of special worship?

[ Ruggles I if you walk up to a church...

You don't get into the church and then turn 'round to see the altar behind you.

The sacred stuff is ahead of you.

And by that same argument...

You might expect that the sacred stuff at stonehenge...

[ Chanting I

the new discovery upends our assumptions.

If winter's sunset was most important...

What other secrets of the universe are hidden within stonehenge?

For answers, we must push past the stones...

Pointing to the sunrises and sunsels that have dominated observations here.