Original subtitles

Narrator: Pyramids, temples, tombs --

these ancient wonders promise even greater secrets

still to be found beneath the sands of egypt.

Now cutting-edge science

decodes the mysterious land of the pharaohs.

With modern technology, we are gaining an insight

into the way the ancient egyptians lived

and the manner in which they died.

Narrator: This time, the mysteries behind

the decline and fall of ancient egypt.

Did volcanic eruptions thousands of miles from egypt

help take down the pharaohs?

Darnell: Climatic and political instability --

that's when it's going to cause a major change.

Narrator: Can scientists recreate

the face of a wealthy woman

who lived in ancient egypt's final years?

Carroll: We're essentially bringing her back to life.

For the ancient egyptians, this is life after death.

Narrator: And are the monuments that did survive egypt's fall

now doomed to destruction?

We risk losing egypt's heritage forever.

Narrator: Ancient clues unearthed...

Long-lost evidence reexamined...

Precious artifacts brought into the light of the 21st century...

These are "egypt's unexplained files."

-- captions by vitac -- www.Vitac.Com

captions paid for by discovery communications

for over 3,000 years,

egypt was ruled by the pharaohs.

But over the course of three centuries,

they slowly lost their grip on power

to leave egypt facing a chaotic downfall.

Open revolt in the streets and famine.

Manning: Dramatic tales of political chaos

and everything breaking down.

What might be triggering this chaos?

Narrator: Now can climate science

and clues buried in the polar ice caps

explain the terminal decline of the ancient pharaohs?

Manning: There's so many changes,

so many shocks that a society can withstand

before it breaks.

Narrator: 305 b.C.E. --

The ptolemaic dynasty begins its rule of egypt.

The ptolemies were the descendants of ptolemy,

who was one of the generals of alexander the great.

Ptolemy managed to seize egypt,

and his family then ruled egypt

the next 300 years.

Narrator: Under their rule, egypt flourished

as a cultural and economic powerhouse,

building great monuments like the lighthouse of alexandria.

But this era was still marked by civil unrest

caused by famine.

Suddenly, there's no food available,

or at least food is in short supply.

And if it wasn't being dealt with to their satisfaction,

then they would want to rise up and revolt.

When the agricultural cycle does not look great,

you can understand that people are going to panic.

The king is someone who is supposed to

promote justice and order and destroy chaos.

Narrator: Famine after famine

undermined attempts by the ptolemies

to govern egypt effectively.

Now egyptologists are searching for clues to explain

why famine hit this era so often.

Their first clue is the nile.

The river's annual flood was crucial to life in egypt.

Without the floods, they can't grow the crops.

And if they can't grow the crops, then they can't eat.

Narrator: Historical records reveal periods

in the ptolemaic era

when the nile floods didn't arrive.

An international team of climate scientists

search for evidence to explain why.

They uncover clues thousands of miles from egypt

in the polar ice caps.

The scientists drill core samples from the ice.

They reveal geological records

stretching back thousands of years.

Naunton: They found in a number of these cores sulfur particles,

which arrived there as a result of volcanic eruptions.

Narrator: Scientists know that giant volcanic eruptions

can have a direct effect on global weather patterns.

Manning: We know volcanoes are an important forcing mechanism,

climatologists say, for global climate for cooling.

Narrator: When volcanoes erupt,

they blast clouds of sulfur dioxide

high into the stratosphere.

It forms a layer of sulfate particles,

which reflect sunlight back into space, lowering temperatures

and changing patterns of rainfall around the globe.

It has to be a certain size eruption

that puts sulfates and ash into the stratosphere,

and that circulates globally or hemispherically.

That reduces the amount of sun hitting the earth's surface...

...Which, in turn, affects how the monsoon is operating.

Narrator: Now scientists ask if volcanic eruptions could explain

the failure of the nile to flood in ptolemaic egypt.

Researchers analyze the ice cores

in their field labs.

They detect spikes in the concentration

of sulfate particles,

which allows them to date ancient volcanic eruptions

with astonishing precision.

For the volcanic record in the ice cores

in greenland or the antarctic,

we can understand volcanic eruptions in a sequence

plus or minus a single year.

♪

naunton: And what's really interesting about this

for egyptian history is that those eruptions

seems to have taken place in the ptolemaic period.

Narrator: But could these eruptions really have affected

the flooding of the nile?

Research teams at nasa

create computer simulations to test the theory.

Manning: Scientists can measure temperature changes,

reconstruct temperature patterns in the world,

reconstruct rainfall patterns in the world in some detail.

Narrator: The computer modeling reveals

the massive sulfate particles from volcanic eruptions

in the northern hemisphere

pushes the monsoon rains further south, away from egypt,

starving the river nile of water.

Johnston: As a direct result of these eruptions,

there is suppressed rainfall in africa,

and particularly around the area of ethiopia,

which would directly affect the nile.

Manning: Large eruptions and multiple eruptions

closely spaced together can perturb a river like the nile

for, sometimes, a decade, possibly even longer.

Narrator: Researchers now compare the dates

of these volcanic eruptions with the dates of famine

and social unrest in egypt.

They uncover a compelling link.

Johnston: In the 40s b.C., we have evidence from

the ice cores of major eruptions happening throughout the globe.

And in egypt, we have the roman writer pliny

recording the nile has reached its lowest ebb ever seen.

This results in major starvation throughout egypt

and also in major civil unrest.

Surely, this must be more than mere coincidence.

Carroll: The two pieces of information,

the historical and the scientific,

are really working together

to build a bigger, clearer picture of this.

Narrator: The ptolemies finally lost control of egypt

to the romans in 30 b.C.E.,

but science has now revealed

that it was not just the romans they had to battle.

For centuries, their rule was undermined

by dramatic climate events

brought on by volcanic activity thousands of miles away.

Darnell: Climatic instability coming at the same time

as political instability,

that's when it's going to cause a major change.

Johnston: We have outsiders sitting on the throne of egypt,

and what the egyptians see is starvation.

They see the nile failing to flood.

They have genuine concerns about the people

who are running the country.

The climate change undoubtedly destabilizes egypt.

♪

narrator: Hidden deep in the vaults

of an australian university --

the long-forgotten head of an unidentified mummy.

This mummified head had been in storage.

Carroll: It'd basically been left in the vaults

for near a hundred years.

Narrator: Now can this mummy's head reveal vital clues

to the life and death of an individual

from one of the last generations

to live under the rule of the pharaohs?

And can the very latest 3-d printing technology

reveal their true face?

Can we say anything about who this person was?

When did they live? How did they die?

Narrator: 2016.

A long-forgotten mummified head is discovered in a collection

at the university of melbourne.

Experts are unsure of its origins.

They turn to radiocarbon dating and analyze

a fragment of detached bandage from the head.

This process can reveal

when this person may have lived and died.

Radiocarbon dating, it's one of the greatest tools

for archeologists and scientists.

We can actually give a date range.

Narrator: Scientists reveal the mummified head dates

to between 300 b.C.E. And 30 b.C.E. --

The final years of egypt's last pharaohs,

the ptolemies.

Now researchers want to find out what clues this individual

could reveal about this remarkable era.

But they're worried that after nearly a century

locked in a vault, the head may have deteriorated.

Because the head was wrapped,

there may be decay happening beneath the bandages.

Naunton: There was a great concern

that its condition had worsened and was continuing to worsen,

and something needed to be done.

Narrator: For the first time in 90 years,

the head is scientifically examined.

It's tightly bound in bandages darkened with embalming oils,

evidence of the highest grade of mummification

and a major clue to who this person was.

Johnston: The very fact that this individual had been

mummified suggests that they are part of egypt's elite.

Mummification was a time-consuming,

expensive process.

Narrator: The team hopes the head will reveal

further clues to this person's story.

But there's a problem --

the bandages are preventing team

from studying the skull in detail,

and removing them is out of the question.

To actually unwrap the mummy would be, you know,

a slightly undignified and disrespectful.

Naunton: After all, this is the remains

of a deceased human being.

It was very deliberately wrapped in this way,

and they wanted, as far as possible, to maintain that.

Narrator: Science offers a solution --

a c.T. Scan.

It allows researchers to see right inside the head

without damaging the bandages.

They're astonished by what is revealed.

Far from having deteriorated,

the skull is in near-perfect condition.

It allows researchers to take precise measurements

that determine the gender and age of this ancient egyptian.

Naunton: Based on the bone structure, the angle of the jaw,

the roundness of the eye sockets,

this was definitely the skull of a woman.

Carroll: To determine the age,

the first thing that we would look at is the teeth.

They were able to age that this is a young female

of 18 to early 20s.

Narrator: The researchers name this woman meritamen.

It means "beloved of amun,"

the king of the gods in ancient egypt.

Meritamen would have witnessed great changes

to the egyptian way of life

brought about by the ptolemies.

Naunton: They influenced egyptian culture

in numerous ways.

The greek language becomes established

as the principal administrative language.

They introduce currency, architecture,

and art takes on a new greek influence.

And this is the world in which meritamen lived.

Narrator: Meritamen may have been of high status,

but researchers discover evidence in the c.T. Scans

that while she may have enjoyed the privileges of wealth,

she also endured agonizing pain.

The scans reveal missing teeth, vast amounts of tooth decay,

and exposed dental roots.

Johnston: For the ancient egyptians,

tooth decay frequently came about from the amount of sand

that was to be found in processed foods.

And this sand would gradually erode the enamel of the teeth,

exposing the roots and causing severe pain

at a time when there really was no dental medicine to speak of.

Narrator: This is a vivid insight

into the agony meritamen endured right up until the day she died.

But the team wants to reveal even more detail

about this woman,

and undertake an ambitious challenge --

to reconstruct her face.

They use the precision data from the c.T. Scans

to program a 3-d printer.

Johnston: It is a time-consuming process,

and, certainly, for this particular skull,

it took 140 hours.

Narrator: Slowly, a precise replica of meritamen's skull

materializes inside the printer.

When it's complete, the model reveals

further tiny but crucial details,

clues hidden inside the cranium

that suggest a serious blood disorder.

Carroll: The c.T. Scanning and with the 3-d model

showed evidence for thinning and pitting on the skull itself.

It's looking like she was possibly anemic.

And with anemia, there's a lack of red blood cells.

The body is essentially struggling for oxygen.

And when that happens, the bone marrow starts to swell.

And this has created what appears on the skull

of the mummy's head.

Narrator: The draining effects of anemia

would have taken a heavy toll on meritamen,

robbing her of all energy.

This diagnosis shines yet more light

on the final stages of her short life.

It's almost certain that during her final days,

this young woman would have been confined to her bed.

She would have been unable to move about.

She would have been exhausted.

And although we don't as yet know precisely how she died,

there are two major contributory factors there.

Narrator: Now researchers hope to uncover even more

by revealing exactly what she looked like.

A forensic artist attaches 3-dimensional plastic markers

at key points on the face and head.

Naunton: And these represent tissue depth,

which is based on population averages.

And this could then be used to recreate the soft tissue,

the musculature, in clay.

And, slowly, the team could begin to build up

a picture of the face of the individual.

Narrator: Using her specialist knowledge of anatomy,

the forensic artist then meticulously builds up

the layers of muscle and tissue.

Slowly, layer by layer, the face of a woman

from the time of egypt's last pharaohs begins to emerge.

Carroll: By recreating the face,

we're essentially bringing her back to life.

And we've given her now, you know, a personality

which, for the ancient egyptians,

you know, this is life after death.

♪

narrator: Finally, the true face of meritamen is revealed.

She was a high-status young woman

who lived over 2,000 years ago,

witnessed the unique rule of egypt's last pharaohs,

and may have succumbed

to the debilitating effects of anemia

and severe, untreated dental infection.

Through this process,

we have now recreated a young woman,

and we have shown not just an object in a museum

but someone who once lived and breathed in ancient egypt.

♪

narrator: For decades,

archaeologists have looked for a lost ancient capital

that seems to have vanished from the face of the earth.

It was known as itjtawy.

Wendrich: This was the capital in the middle kingdom.

It's the center of egypt at that period.

So where did it go?

How do you pinpoint a lost city, buried beneath the sand?

Narrator: Now can egyptologists combine

the tried and tested method

of ground coring with remote sensing technology

to finally track down this missing metropolis?

Narrator: Itjtawy was once a flourishing capital,

until it experienced a fatal decline

and was lost forever.

In 2015, archaeologists initiated a new search

for this ancient city.

They began by looking for written clues.

We have textual references to itjtawy,

the middle kingdom capital of egypt

in the 12th dynasty.

Wendrich: The kings of the middle kingdom

hail from an area near to faiyum,

so we can expect an enormous city, but it's not there.

Narrator: Itjtawy was documented

as egypt's capital for 350 years,

until around 1785 b.C.E.

But no physical evidence of the city has ever been found.

The written records link the city to king amenemhat,

a ruler from the middle kingdom.

His pyramid still stands at el-lisht in the faiyum region.

The theory is that it was built to overlook the capital

he once ruled.

Wendrich: We know approximately where it is, but that area

is still 10x10 kilometers, which is a big area to research.

Plus, it has been buried probably under meters of mud.

And that's really not possible with the traditional techniques.

Narrator: The location of the ancient king's pyramid

is a starting point,

but investigators need a way to narrow down the search area.

They turn to satellite imagery for help.

It allows them a wider view of the landscape of this part

of egypt from 450 miles above the earth's surface.

Lacovara: We have to rely on satellite imaging now.

New techniques are helping add to our tool kit in order to try

and find these cities when they're lost without a trace.

Satellite archaeology enables us to find

all these disturbances and differences in the surface.

If you see differences that don't look natural

but that form straight angles or lines or circles,

then you know something is up.

Narrator: Satellite imagery must be analyzed for telltale clues.

Ancient texts record that itjtawy was built

on the banks of the nile.

But the river has shifted its course over the years.

Now archaeologists ask if this could explain

the ancient city's ultimate demise.

Naunton: If the nile has moved

and itjtawy was built on its banks,

is it possible that the river might have moved

and swallowed it up over time?

Narrator: The movement of the nile

has left subtle traces in the desert landscape.

When scientists study a satellite image of an area

where the river once flowed,

they discover an exciting clue --

a raised expanse of ground

located close to amenemhet's pyramid shows signs

that it was once densely inhabited.

The data from the satellite imagery allows us to see

that there is an area which is somewhat raised.

It seems to indicate human interaction with the landscape

on a large scale,

which allows us to ask the question,

"could this be the site of itjtawy?"

narrator: Satellite technology can only take the search so far.

The fundamental techniques of archaeology

must now be used to try and solve this mystery.

You have to do what we call ground truth.

One way of doing that is by coring, by drilling a deep hole,

and pulling out a cross section of centuries of history

and just analyzing carefully from every layer in that core.

Naunton: Rather than covering a single large area

very comprehensively,

you send a kind of probe into the ground

just to look for cultural material.

Narrator: The coring team probe 5 meters beneath the surface.

The layers of the cores reveal different periods

throughout history.

Archaeologists are searching for any signs of human habitation.

They find key evidence dating to the period

of egypt's middle kingdom,

when itjtawy would have been a prosperous city.

♪

the cores yielded fragments of middle kingdom pottery.

Johnston: There are potsherds

and various other pieces beneath the ground,

which seem to indicate this has been an inhabited area.

Narrator: The pottery sherds date to

when itjtawy was a flourishing capital.

But as the large-scale coring project continued,

many of the samples amazed archaeologists,

as the evidence of a jeweler's workshop

is discovered within them.

Wendrich: You don't get a workshop with gemstones

in your average village.

So this indicates that we are hitting

a very important settlement.

Lacovara: Agate and carnelian

that had been smashed to make jewelry,

and often these kind of jeweler's workshops

are associated with the royal palace.

Narrator: This is a crucial clue.

Evidence of a luxury industry, like a jeweler's,

suggests this was once the site

of a vibrant, wealthy ancient city.

This may then be a thriving city and possibly itjtawy.

♪

narrator: After decades of study,

full-scale spade and soil excavations can now begin,

and this ancient, fallen capital may finally be uncovered.

♪

precious ancient sites and artifacts are under attack

as new discoveries are found submerged in water.

This is a major threat to the archaeology of egypt.

Narrator: Now cutting-edge satellite technology

is being used to try to explain why archaeological sites

that were once dry as dust are now soaking wet.

How might we explain this bizarre phenomenon?

Narrator: 2017 -- a suburb east of cairo,

and an incredibly rare find is made --

a 206-year-old monument of pharaoh psamtik the first.

Johnston: Excavators discovered, quite by chance,

a colossal, 26-foot-high, quartzite statue.

Narrator: But archaeologists are dismayed

by the conditions the statue is found in.

The soil is waterlogged.

Even though the statue was found not too far beneath the surface,

it was as though the statue had to be pulled

out of a pool of water.

Narrator: This is not an isolated incident.

At the 2,000-year-old

kom el shoqafa catacombs of alexandria,

rising groundwater has damaged the breathtaking stonework.

It took emergency engineering works in 2019 to save it.

Meanwhile, at the colossal temple of luxor,

the stones are being eroded by water damage.

We're beginning to see signs of surface damage

on the stonework and on the carvings and on the reliefs,

appearing as a crystallized white powder

on the stonework itself.

And in its most extreme examples,

whole areas of carving

just simply crumble to dust.

Clearly, this is putting some of the country's

major archaeological sites at severe risk.

Scientists are trying to find out

where this water's coming from and how they can hold it back.

Narrator: Many researchers believe the root of this problem

can be traced back to the 1960s

and the construction of an engineering giant --

the aswan high dam.

Naunton: This was undertaken

to provide egypt with hydroelectric power,

but also to allow the land in the nile valley

to be farmed throughout the year.

Narrator: The dam provided water for the crops

by flooding extensive areas.

Several of egypt's ancient monuments

had to be relocated along with over 90,000 citizens.

But 50 years after its completion,

the problem of rising water is getting worse.

Modern scientists are studying the landscape

for clues to explain why.

Carroll: Scientists are using remote-sensing g.I.S. Techniques

to look at how the land has changed

over the last few decades.

Narrator: Analysts collect data from a camera

known as the advanced spaceborne

thermal emission and reflection unit.

This is mounted on the terra satellite, which orbits earth.

♪

satellite images taken over the course of the last 30 years

allow scientists to show that urban areas have expanded

and developed very rapidly with the loss of agricultural land.

Narrator: The images show changes

to how the remaining farmland is being cultivated.

Areas of desert are now being reclaimed for farming,

which means that water is now being introduced

into parts of the country

which were previously completely bone-dry.

Narrator: Scientists believe that the flooding

caused by the aswan dam to help farmers

has also led to a rise in the level of groundwater.

Now as modern farming and irrigation intensifies,

the water level is continuing to rise even further.

Naunton: All this agriculture requires an awful lot of water

to sit on the land more or less permanently,

right the way throughout the year.

And this has had a knock-on effect.

Carroll: They're basically pumping out more water

from the nile, and this is causing

more of a runoff of water,

which in turn is then going to affect the archaeological sites.

Egypt is turning slowly into a swampland.

Dodson: Walls which were many meters away

from any source of water

now have water directly underneath them.

Narrator: For archaeologists, this is disastrous.

Some of the nation's most important sites

are facing imminent danger.

But even more alarming, the rising waters

may be destroying a multitude

of undiscovered artifacts right now.

Dodson: The reasons why

we have so much material from ancient egypt

is the dry conditions have meant

that organic materials have survived.

The rise in the water is worrying simply 'cause it means

that far less is going to be preserved.

Naunton: The more vulnerable ancient monuments are

to things like rising groundwater,

the more those things stand to be lost

before archaeologists get to them.

Narrator: Now egyptologists and scientists

are working more closely than ever to search for

and save egypt's hidden history before it's too late.

Carroll: It's actually crucial that we act now

to protect these monuments.

Johnston: We need to resolve this problem

quickly and affordably.

Otherwise, we risk losing egypt's heritage forever.

♪

narrator: These portraits were found alongside

carefully preserved mummies.

They're unlike any depictions of ancient egyptians.

They show the faces from after the fall,

a new ruling class revealed in unprecedented detail.

Carroll: You're instantly struck by their expression.

They're so lifelike.

Narrator: Now scientists ask if the extraordinary details

of these paintings could contain clues

to the rare health conditions suffered by egypt's new elite.

Can the pharaoh mummy portraits

tell us even how those individuals lived

and possibly died?

♪

narrator: 2016.

A team at chicago's northwestern university

analyze a selection of striking images.

They were discovered south of cairo in faiyum.

Many of these portraits were found covering

the face of a mummified body.

Where earlier egyptian artwork was highly stylized,

these images are extraordinarily lifelike.

Altaweel: It doesn't look like something

they would put on a mummy.

They literally look like just portraits,

like as if you'd put a picture on a wall of someone.

They really wanted you to see

a more lifelike representation of the person.

Narrator: The portraits depict wealthy egyptians

who lived during the first three centuries a.D.

This was a time during which the roman empire

consolidated its rule over egypt

and mediterranean customs influenced daily life.

This time, egypt's quite a multicultural place.

You see greek and roman files.

The depictions of the faces, for instance,

very roman-looking realism,

greek style of decorations in terms of the hair, the jewelry.

But then a very egyptian idea of putting a body

in a sarcophagus and mummifying it.

The portraits represent the cosmopolitan nature

of egyptian society at the time.

Narrator: But scientists believe these portraits can tell us

about much more than the changing culture of egypt

under the romans.

The faiyum portraits, incredibly,

might offer scientists an opportunity

to say something about the health of the individuals

and the diseases that they might have been suffering from.

Narrator: Researchers at northwestern university

begin by analyzing each image

under different wavelengths of light.

Johnston: With modern scientific techniques,

we're able to analyze the faiyum mummy portraits

in the way that we might be able to analyze

a renaissance painting.

Altaweel: Using photogrammetry techniques,

we can begin to understand the sort of processes used

to make the object, technologies,

but also the kind of materials

that would go into creating these objects.

Narrator: This process reveals

the special pigments and complex techniques

used in each portrait.

For researchers,

it's clear the artists went to great lengths

to create the highly realistic images,

like this portrait of a young man.

Medical experts ask if the drooped features

depicted in the portrait could be evidence

of a neurological disorder.

To find out, scientists turn to his preserved skull

and subject it to c.T. Scanning.

♪

naunton: What appears in the portrait

to have been an anomaly in the soft tissue on the face

is backed up by the measurements from the skull.

The individual was suffering from some kind of atrophy

of the soft tissue and the bone underneath.

The scientists concluded, therefore, that in this case,

he was indeed suffering from parry-romberg syndrome.

Carroll: The study actually revealed

significant neurological conditions,

signs of a very rare condition, which is parry-romberg.

And what this does is it actually causes shrinkage

to the face.

Narrator: The details of the faiyum portraits

may reveal even more.

Scientists know that evidence of neurological disorders

can be found not just in the skull,

but also in our eyes.

Altaweel: Medical science beginning

to just use people's faces to recognize disease.

For instance, strokes or other kinds of ailments that may occur

can be recognized using a facial recognition software.

Naunton: The eyes are often the first part of the body

to be affected by neurological diseases.

Narrator: Researchers now ask

whether the highly detailed depictions of eyes

in the faiyum portraits

could hold further clues to other disorders

suffered by these egyptians.

We can begin to apply the same technologies

to look at these ancient portraits.

Narrator: In modern medicine,

doctors measure how light is reflected

from a patient's corneas.

If these corneal reflections are not symmetrical,

it can be a sign of a neurological disorder.

In the faiyum portraits, the corneal reflections

are represented as flecks of white paint.

♪

carroll: Now modern scientists

are actually looking at this for evidence,

possible health disorders from a neurological point of view.

Narrator: Just like doctors diagnosing a modern patient,

researchers measure the position of the corneal reflections.

When they compare the results to data taken

from the actual skulls, they're astonished.

Naunton: Scientists are able to say that the way the eyes look

does suggest that they were accurately capturing

what are the signs of neurological diseases.

Altaweel: Science is telling us that these faiyum portraits

are more than just pretty pictures.

Naunton: In many cases, it seems

the artist did accurately capture the conditions

that some of these people were suffering from.

Narrator: The portraits of the faiyum mummies

are not idealized, airbrushed images,

but are as close as we have to photographs

of egypt's new cosmopolitan elite.

♪

only 28 egyptian obelisks remain standing,

each of them a towering giant.

Obelisks are the ancient world's skyscrapers.

Godenho: From miles and miles away,

people could see these things standing tall.

They're ancient feats of engineering.

Narrator: Now modern researchers are asking

just how the egyptians, equipped with only basic tools,

carved these behemoths.

Fletcher: Now it's almost miraculous

how the ancient egyptians

create these amazing structures from solid granite.

How did they do it, and what tools were they using?

Narrator: Obelisks could be over 100 feet tall,

each carved from a single piece of granite,

cut whole from the rock face.

For the pharaoh who ordered this gargantuan task,

the obelisk was a statement of divine authority.

Godenho: When you look at the form of obelisks,

they end with this pyramid on top.

That's a symbol of the sun god.

So we're talking about the relationship

between the king and the sun god.

Altaweel: Obelisks really symbolized

the entryways of the gods,

the connection between our world with higher powers.

Narrator: Ancient egyptians had to cut through solid granite,

one of nature's hardest rocks,

yet only had tools made of soft metals

like copper and bronze.

How did they do it?

A vital clue can be found at a quarry in aswan --

an enormous unfinished obelisk,

abandoned by workers 3,500 years ago.

Godenho: Looks like this thing was almost ready

to be released from the quarry it was carved in,

but then a crack was exposed in the obelisk,

and so it had to be abandoned.

Bianchi: If it did not develop a crack,

it would have been the largest standing obelisk that we know.

Narrator: The unfinished obelisk shows signs

of what seem like strike marks.

We know ancient egyptians carved soft rock,

like limestone, using copper chisels.

But to cut granite, it would take a harder metal like iron,

which had not yet been discovered.

Harrison: The evidence on the aswan obelisk implies

that it was being hammered

and beaten out of the ground using copper chisels,

but this seems slightly unusual

because copper is quite a soft metal

compared to the very hard granite.

Narrator: Other scholars believe it's more likely

that the ancient workforce

used rocks made of dolerite to free the obelisk.

Bianchi: Using pounders

about the size of a modern bowling ball

upon the granite

until the granite was worn away.

It's almost inconceivable that such a simple technology

could do this, but possibly with enough people,

you could move something this large this way.

Narrator: But now researchers are reevaluating

an important clue

discovered in the 19th century

by the father of egyptology, flinders petrie.

Godenho: Petrie working at giza,

where the pyramids are, near cairo,

he found granite-drilled cores --

lumps of granite that look like they'd been removed

from the earth by drilling action.

Narrator: This could be a crucial piece of evidence

in solving this mystery.

Petrie's theory was that while the drills were made of copper,

craftsmen needed the help of some other substance

to cut through granite.

Petrie believed that in order for these drills

to be effective, they needed a hard cutting edge.

So something else, not just the metal.

And so he thought something like diamond

would be suitable for that cutting action.

Altaweel: We use diamonds to drill.

Presumably, they would have used something

sort of comparable in hardness as diamond.

Narrator: 21st century researchers

may have found the answer to this mystery

in new york's metropolitan museum of art.

Naunton: There is an object

which perhaps doesn't look like much

but actually is telling us an awful lot

about how the egyptians were able to work stones like this.

Narrator: This piece of ancient sculpted stone

was discovered in amarna in the late 19th century.

Contemporary researchers are intrigued by a hole

on the back of the artifact.

A tubular cutting edge,

a tubular drill had been used on this.

And at the bottom of that drill hole,

you can see a circular area.

Naunton: There are traces of some kind of abrasive powder

that they used to remove this section.

Narrator: This fine powder could finally explain

how egyptians cut through hard granite with soft copper.

The fragment is taken immediately to the lab

to be examined.

Naunton: This powder's been studied by electron microscopy,

and it's been shown to be made of a mixture

of various substances, but two of those stand out.

There are green fragments which seem to be

from bronze and copper, perhaps the remains of a drill.

And there are red angular crystals in there as well.

Narrator: Scientists analyze the red crystals

and identify them as corundum.

It is one of nature's hardest materials,

second only to diamond

and many times harder than granite.

Godenho: Corundum's actually a super-hard crystal,

and that's what we seem to have fragments of here.

But it's still used today because it can scratch

just about any other gem.

Narrator: Today, corundum is used

to coat the cutting surfaces of industrial drills

designed to cut through rock.

Now science has revealed that 3,000 years ago,

ancient egyptians did exactly the same thing

to carve their vast obelisks.

Altaweel: The obelisk is beginning to reveal

new information to us.

Now we're learning much more.

We're learning about the way they were made.

That's beginning now to be peeled away by new techniques

and technologies available to us.

Narrator: It's evidence of the ingenuity

of the ancient egyptians

and of their ability to make the most

of their natural resources

to overcome seemingly insurmountable tasks.

Bianchi: The more we study ancient egypt,

the more we are aware

of just how attuned they were

of how nature works.

♪