All language subtitles for Ancient.Engineering.S01E10.The.Taj.Mahal.And.The.Golden.Age.Of.Islam.1080p.AMZN.WEB-DL.DDP2.0.H.264-NPMS_track3_[eng]

- [Greg] We are surrounded
by extraordinary feats

of engineering, constantly
pushing the boundaries

of what's possible

- Without engineering,
there'd be no modern world.

- [Greg] Gigantic cities,
amazing infrastructure

and ingenious inventions.

- Engineering is the key to
turn dreams into reality.

- [Greg] To reach
these dizzying heights

today's technology
relies on breakthroughs

made by ancient engineers.

- It's mind boggling
how they did this.

- [Greg] How did early
civilizations build

on such a scale?

- They raised the
bar for construction

in a way that no one
thought possible.

- The sheer engineering ability

that is in itself impressive.

- [Greg] By defying the
known laws of physics

and daring to dream big.

They constructed
wonders of the world

from gigantic pyramids
to all inspiring temples

and mighty fortresses all
with the simplest of tools.

- Can you imagine the skills
people would have needed

to build like this?

- [Greg] Now it's possible
to unearth the secrets

of the first engineers.

- They managed to construct
edifices that has survived

the ravages of time.

- [Greg] And reveal
how their genius

laid the foundations for
everything we build today.

[dramatic music]

Standing proud over a
city built in the desert,

the tallest structure
in the world.

At just over 2,700 feet in
height, the Burj Khalifa

in the United Arab Emirates
embodies the financial power

of the modern Middle
East, but it style also

reflects the region's rich
cultural and religious history.

And it's not alone.

The design of many modern
buildings is influenced

by their Islamic heritage.

Qatar's Al Thumama
stadium, built for the 2022

soccer world cup
represents the taqiyah,

a traditional woven
cap worn by males

across the Arab
world and beyond.

Morocco's Marrakesh
Menara Airport,

clad in white aluminum
panels feature stylized

Islamic ornamental designs.

And the design of the Petronas
Towers in Kuala Lumpur,

Malaysia is based
on the five pillars

of the Islamic religion.

The cross section of
the towers reflects

the eight pointed star, a
symbol of Islamic culture.

The engineering roots of these
structures can be traced back

to what's known as
Islam's golden age,

one of the greatest
periods of scientific

innovation in human history.

- The modern world owes
much to what we can consider

the golden age of
Islam which lasts

from the eighth to
the 13th century.

- There's a huge
amount of innovation

in terms of architectural
development.

- Which fundamentally
changed the way

that people think in
terms of geometry,

mathematics, astronomy,
and education.

- [Greg] But what led to
this new way of thinking

and ultimately to a revolution
in Islamic engineering?

From the seventh and eighth
century Islam spread outwards

from its birthplace in Arabia
through the Middle East,

parts of Asia, North
Africa and even into Spain.

The religion expanded
through military conquest,

trade and pilgrimage.

- What was so special is that
there was an introduction

of people from such a vast area

within one religious community.

People from North
Africa and people

from the borders of
China and from India

would all congregate, exchange
ideas, philosophies, texts.

- [Greg] Islamic scholars
were open-minded,

absorbing knowledge from
all possible sources.

- They were not afraid to
draw upon scholarly traditions

in earlier cultures
and civilizations,

particularly from the Greek
and Roman world on the one hand

and from the Persian and
Indian worlds on the other.

- [Greg] They developed many
of the most advanced ideas

of the age.

At this time Europe was
reeling from the collapse

of the Roman empire.

The continent regressed
into a period known

as the dark ages.

- This time in Europe,
we can kind of think of

as a period of ignorance,

a period of oppression
where we don't have

these same advances that we're
seeing in the Muslim World.

- And one of the most notable
of these Muslim scholars

was a man called
Ismail al-Jazari.

He is seen today as the
founder of mechanics.

- [Greg] Al-Jazari wrote
an influential work

called the book of
knowledge of ingenious

mechanical devices.

It featured meticulous diagrams
and colorful illustrations.

- He designed objects
that could appear

to be like mechanical
robots of their time.

So they would be exquisite
birds that look real

and then their
wings would open up.

- [Greg] It led to the
invention of mechanical clocks,

combination locks, and
even the crank shaft.

The crank shaft helped
improve water irrigation

and today is a central component
of the automobile engine.

Although built before
the Islamic golden era,

the waterwheels found
in Hama, Syria benefited

from an Islamic
mechanical innovation.

The flywheel helped watermills
smooth out the delivery

of power, allowing some to
lift as much as 660 gallons

of water per minute.

But mechanical devices
weren't the only advances

being made in the Middle
East at this time.

As the Islamic faith
spread so too did the need

for worshipers to
come together to pray.

And Islamic engineering prowess

would produce a new and
important structure, the mosque.

- We can consider the mosque
to be the architectural type

that most visually
expresses Islam.

- They were statements of
power as much as anything else.

They were designed to attract
people to come towards them.

So you have these wonderful
domes and these minarets

and also the noise of
the call to prayer.

They were like a magnet
for the local community

- [Greg] Beginning
as humble courtyards

where the faithful could gather

they soon grew into
incredible buildings,

housing thousands of worshipers.

But as numbers of
the faithful swelled,

ever larger interiors
were needed.

One vital engineering
breakthrough would enable

Islamic engineers
to build bigger.

- One of the most
consistent features

in Islamic architecture
is the dome.

- [Greg] It may be the
mosque's defining feature,

but the dome was not originally
an Islamic invention.

Islamic engineers
drew on advances made

by an earlier
empire, one renowned

for its magnificent buildings.

Grand and innovative
structures dominated

the skyline of ancient Rome.

- The Romans were certainly
one of the earliest people

to recognize the architectural
potential of the dome

and it allowed them to build
enormous internal spaces

without necessary supports.

- [Greg] The greatest
example of a Roman dome

sits atop the Pantheon, a
temple completed around 126 AD.

It weighs an
astonishing 5,000 tons.

- It was the first
time that the Romans

had actually worked out how
to build a massive building

without any internal support.

It's mind-blowing even today.

- [Greg] Roman
engineers realize that

by rotating and extending
the arch element

they can create a strong
three-dimensional shape, a dome.

- A dome is built
by taking advantage

of the forces of compression,
which point towards the top

of the dome and tension which
point towards the bottom.

And the Romans use
huge concrete pillars

around the bottom to
absorb that tension.

- [Greg] Five and
a half centuries

after the completion
of the Pantheon,

the evolution of the
Islamic dome began.

Following the successful
Muslim assault on Jerusalem

in the seventh century,
construction started on the Dome

of the Rock.

Its architecture was based
on nearby Byzantine churches.

But this was the first major
Muslim building intended

for public worship even though

it wasn't technically a mosque.

It's origins are
shrouded in mystery.

- No one really knows why the
Dome of the Rock was built

but it's of incredible spiritual

and emotional and
political importance.

- [Greg] The building
was constructed

at the end of the
seventh century,

possibly with a dome being
added to an existing structure.

There have been centuries
of debate over its purpose.

- It was believed that
this particular spot

was where Muhammad flew on
a winged horse for Mecca

and ascended into heaven.

- [Greg] Other scholars believe

it's associated with Islamic
and Byzantine beliefs

about judgment day,
but there's no doubting

this structure's
lasting significance.

- The Dome of the Rock is
one of the most important

pilgrimage sites in
the Muslim world.

And it's really important
because it is one

of the earliest dated
Muslim buildings.

- [Greg] The original
dome collapsed

in an earthquake in 1015 and
was rebuilt seven years later.

And down the years, it's
had a number of upgrades.

In the 17th century
under the Ottoman empire,

the exterior mosaics
were replaced

with colored ceramic tiles.

The actual dome was most
recently renovated in the 1990s

when it was coated with
a layer of 24 karat gold.

Modern day mosques are
adding spectacular shapes

to sometimes uniform cityscapes,

challenging engineers to stretch
the limits of construction.

Completed in 1986,
the Shah Faisal mosque

in Islamabad,
Pakistan was designed

in the shape of a Bedouin tent.

The main structure
of the building

is the central prayer hall,
supported by four concrete

girders and covered
in white marble.

The Sheik Zayed Grand
Mosque in Abu Dhabi

in the United Arab
Emirates features 82 domes.

One of these is the
largest dome of its kind

in the world at
nearly 280 feet high

with a diameter of 108 feet.

But breaking from the
tradition of marble and stone

is the Kristal
Mosque in Malaysia.

Opened in 2008, the mosque's
exterior makes it unique;

a steel and glass
structure giving rise

to its crystalline appearance.

Mosques must be capable of
enduring the ravages of time

so modern engineers often
turn to new materials

seeking the ideal combination
of beauty and strength.

In 2004, a strong
earthquake hit Morocco

in Northwest Africa killing
more than 600 people.

So when engineers
were commissioned to
build a new mosque

in Casa Blanca tremors were
very much on their mind.

Adding to the challenge, the
structure was to be built

on the very edge of
the Atlantic Ocean.

- It was a statement.

Islam has penetrated
right to the edge

of the African continent.

But also there's a verse
in the Koran that says

that the throne of Allah
was built on the water.

And so here is a
physical statement.

Look, this great most
was constructed literally

on the edge of the Atlantic.

- [Greg] The building was
constructed partially on land

and partly over the ocean.

To achieve this a platform
was built to link the shore

with a natural rock outcrop
where a swimming pool

had previously been located.

Two break waters
were put in place

to protect the mosque
from large waves.

Engineers also had to make
the building quake proof.

So scientists got to
work and developed a form

of concrete stronger
than the ordinary type.

The highly resistant
formulation they produced

had a fast setting
time and was capable

of withstanding
immense pressure.

The mosque's roof is covered
with cast aluminum tiles,

stronger than the
traditional ceramic type

but a quarter of their weight.

- The Hassan Mosque in
Casablanca really is

a modern interpretation
of the greatest

of the Moroccan mosques
of the Marinid period

which is in the 12th and 13th
centuries in Moroccan history.

- [Greg] The structure
also features another

cutting edge innovation.

- Something that brings
it into the 21st century,

the large laser that shines
directly towards Mecca.

- [Greg] The Hassan II
Mosque opened in 1993.

It took seven years to
construct, employing
35,000 workers

laboring over 50 million hours.

But such modern day
marvels are reliant

upon an Islamic
engineering innovation

from the ancient world.

Lying in the desert around
100 miles Southwest of Baghdad

is the Palace of Akkadian.

It's thought to have
been built under an early

Islamic dynasty named
the Abbasid Caliphate,

a line of rulers
descended from the uncle

of the prophet Muhammad.

- The palace of Akkadian is
one of the best preserved

early Abbasid's
palaces, but it's one

on which we have practically
the least information written.

We can date it to
around the year 778.

- [Greg] But what made
this palace different

to others that had gone before?

One reason lies
within the building,

an Islamic engineering
development

that went on to have a major
influence on medieval Europe.

For centuries
engineers had made use

of the semicircular arch.

- The purpose of an arch
in a building is to be able

to create space or an opening

so that you distribute
the load around the arch

which means you've got
free space underneath.

In an arch. the load
is distributed evenly
around the arch

in compression, but that
creates a big outward push force

which has to be
resisted by the walls

that are holding
the arch in shape.

- They have a huge advantage
over horizontal beams

or lintels because they can
carry so much more weight.

- [Greg] The force is generated
by semicircular arches

and strong thick supporting
walls were a necessity.

But at the palace of
Akkadian came a breakthrough.

The pointed arch, a
great leap forward

from the heavy Roman arch.

- What a pointed arch enables
you to do is to get higher.

It can bear the same load, but
it can work its way up higher

and create a larger
opening as well,

which allows more light in.

- [Greg] The pointed arch
distributes weight downwards,

not sideways.

So this engineering breakthrough
also meant heavy walls

were no longer necessary.

- What the pointed
arch allows you to do

is build buildings of
unprecedented height and scale.

Because while a Roman
arch, a semicircular arch

is very limited in how far you
can actually draw your walls

apart before it becomes
structurally unsound,

a pointed arch theoretically
you can just keep going up

until you get to the top.

- [Greg] Eventually,
pointed arches would also

become a common feature
of European churches

- Without this engineering
design development

Europe would not have
these amazing cathedrals

that we have today.

The likes of Notre
Dame, Westminster Abbey.

- [Greg] Even today,
engineers are still pushing

arch design to new heights.

In the late 1940s, the
city of St. Louis, Missouri

sought to commemorate its
role in the westward expansion

of the United States.

To do so it was decided to build

a spectacular public monument.

The winning design was
picked in a competition,

a 630 foot arch, a symbolic
gateway to the West.

- It's huge challenges
is of how on earth

do you construct something
that is curving up

like nearly 200 meters high

and stop it falling over and
then allow people to go up

inside the middle of it as well.

So it's very
challenging project.

- [Greg] Construction
of the arch required

some highly sophisticated
engineering.

It drew upon lessons
first learned

back in the ancient world.

The Taq Kasra monument built
around the third century

is a testament to Persian
engineering skills.

Located in Iraq the
arch was once part

of an imperial palace complex.

To enable it to
support its own weight,

engineer's use to design
known as the catenary arch.

- A catenary arch, if you
imagine you've got a necklace

or a chain and you
hold it at the edges

it's the natural shape that
would form under gravity

and self weight of
the material itself.

So you get this perfect curve.

And if you flip that
up the exact same shape

is what a catenary
arch shape is.

- [Greg] For the 20th
century St. Louis Gateway

engineers started with
the structures two legs.

Each leg is embedded
in concrete foundations

44 feet thick and 60 feet deep.

- The engineers and
builders constructing

the Gateway Arch had to
have extreme precision

because even if they made
an error of less than

half a millimeter or 1/64 of
an inch at the base points

when they started building it
wouldn't have met at the top.

- [Greg] The main structure
was erected section

by section, 142
elements in total.

Each resembled a steel triangle
narrowing towards the top.

- The Gateway Arch has
got a thin stainless steel

outer skin and it's also
got a layer of steel

and concrete inside it to
give it strength and rigidity.

But a lot of it is
actually just air

so it makes it lights inside.

- [Greg] The arch was
completed in October, 1965,

taking just over 32
months to construct.

Even today it remains the
tallest arch in the world.

The desire to build
the world's tallest

has long been a driving
force in engineering design,

but in the Islamic world,
building high was important

for one very specific reason.

[prayer hums]

Fundamental to Islam is the
religious duty of daily prayer.

- In Islam there are five
particular times of day

at which Muslims
are supposed to pray

and this is one of the
five pillars of Islam,

these five daily prayers,
which are to be undertaken.

- The way that Muslims know
when it's the time to pray

is by symbol as in
to call out and say,

come, now is the
time to pray to God.

[melancholic music]

- [Greg] But ancient
Islamic engineers

had to find a way to
ensure the call to prayer

could be heard as
widely as possible.

With pointed arches
enabling the construction

of tall towers the
solution was the minaret.

- The minaret is
essentially a tower.

Minaret means light,
it's a place of light.

They do function as
landlocked lighthouses.

It's something that when
you're traveling at night

this series of minarets in
towns and across the landscape

provides a way of traveling.

But their primary
function is for somewhere

for the person to make
the call to prayer from.

People can hear that voice
above the melee below

and know that it was
time to go and pray.

- [Greg] Minarets come
in many shapes and sizes.

- So we, first of all, have
these spiral shaped minarets

like at Samarra.

And then the form of the
minaret is transformed

particularly in Central
Asia into the sort of

tower minarets, the
slender high towers

elaborately decorated.

That is what we now see as
the sort of standard shape

of the minaret.

- [Greg] Although
relatively straightforward

to construct many
these ancient towers

are now under threat
from the modern world.

The Al Khulafa Mosque in
Baghdad was built in 1279

and it's minaret
stands 112 feet tall.

But in recent years
it has experienced

an engineering failure.

- Basically it's
starting to tilt.

- [Greg] The mosque is
better known by locals

as al'ahdab, the hunchback
due to its minaret's

precarious angle.

A 2013 study revealed it had
tilted four feet off center

and was still moving
approximately 0.19
inches per month.

Geophysical surveys
were undertaken to
identify the cause.

- They discovered that the
reason why the foundations

are being undermined
was because wastewater

and sewage from a
nearby municipality pump

was being pumped through the
ground underneath the building.

And that weakened the
structure of the ground

that it was based
on and therefore led

to it starting to tilt.

- [Greg] UNESCO and
the Iraqi government

are developing plans to
prevent the minaret's collapse.

Islamic minarets had
to be taller than
surrounding buildings

as sound waves travel
further with no obstructions.

The same principle even
applies to the very latest

communication
technology of today.

As buildings have grown ever
taller, modern radio towers

also have to reach
higher and higher.

Whether they're for TV,
radio, or cell phones,

communication towers have
become iconic landmarks.

The range of a
transmission is determined

in part by the
height of the towers.

The largest have a reach
of up to 60 to 70 miles,

depending on topography.

From Toronto to
Moscow and Shanghai,

these are among the tallest
structures ever built.

And in Tokyo, engineer's plan
to construct a tower higher

than any that had gone before.

It called for some
innovative technology

as this city is in the middle
of a major earthquake zone.

The new 2,080 foot
tall structure would be

called the Tokyo Skytree.

To protect it from earth
tremors it's design

is underpinned by surprisingly
ancient technology.

Engineers drew inspiration
from a five story pagoda

called the Horyu-ji Temple.

Built more than 1,300 years ago,

it's one of the world's
oldest wooden buildingS.

Despite countless earthquakes
over the centuries,

the structure has
never collapsed.

- These pagodas are
unbelievably resistant

to earthquake forces.

Nobody really knows exactly
why, but a thing called

a shinbashira, which
is a core that goes

in the center of the pagoda
that essentially acts

like a pendulum to dampen
the horizontal force

of an earthquake is
probably one of the reasons

why these are so
sturdy and withstand

these incredible earthquakes.

- [Greg] During an earth
tremor, the shinbashira acts

like a counterbalance
within the temple.

This diminishes the
force of the shock waves

threatening to destroy it.

Emulating this design within
the center of the Skytree,

engineers built a hollow core.

It contains a shinbashira
running the length

of the structure, connected
to the steel frame

of the building by
hydraulic dampeners.

- The outer structure
of the Skytree

is essentially protected
from the full force

of the earthquake because
this central core pillar

provides a bit of
a dampening effect.

- [Greg] But even as it
was under construction

the Skytree was put to the test.

March, 2011 saw the largest
earthquake ever recorded

in Japan.

It measured 9.0 on
the Richter scale

and the epicenter was around
230 miles Northeast of Tokyo.

Severe tremors impacted
the city causing many

skyscrapers to shake violently.

But what about the
unfinished Skytree?

- They were very lucky
because the shinbashira

was already in place
and it did its job

and the Skytree at that
level of construction

still stayed in place.

- [Greg] Before it
was even completed,

the Skytree had earned its
place in engineering history.

Back in the eighth,
century political power

and military might
saw Islam spread far

beyond the Middle East.

In 711, crossing the
sea from North Africa,

a Muslim army landed on what
was to become Gibraltar.

Over the next seven
years it conquered most

of the Iberian Peninsula,
modern day Spain and Portugal.

- The Muslim armies were
very much a land-based force.

They're mainly a
mounted archery force.

So they were able to
fire from horseback.

This is what really made the
European army's struggle with.

They weren't used to people
galloping and firing at them.

- [Greg] But to secure
the lands they invaded

the Islamic forces
relied on advanced

engineering techniques.

As a result Southern Spain
has one of the largest

concentrations of medieval
fortresses in all of Europe.

One of the best preserved
and oldest overlooks

the town of Banos De La
Encina, the Burgalimar Castle.

Its appearance is striking,
dominating the landscape

with its vivid reddish color.

This remarkable defensive
structure also contains

an engineering secret
built into its very fabric.

- The walls are
incredible to look at

and there are 15 towers
which are incorporated

into the exterior.

So it's a very defensive
looking building.

When you look at this castle
it looks like it's built

of stone, but it's actually
built of an Adobe like material

of Arab origin.

- [Greg] Adobe is
made up of materials

that bind together
under compression.

At this time, Islamic
builders were also

using another similar
construction technique

known as rammed earth.

- Rammed earth
buildings are created

by getting a selection
of aggregates.

So clay, gravel, silt, and
ramming it into a structure

which has been built
by wooden frames.

And once it's all
rammed into place

those frames are removed leaving

a very, very substantial wall.

- [Greg] Although this
method can be labor intensive

it has a very low
environmental impact.

It makes use of locally
available material rather

than transporting
stone from far away.

Rammed earth construction
techniques date back

thousands of years but
their use increased

with the expansion of Islam.

Invading Islamic
armies use this form

of engineering across North
Africa and into Europe,

building large fortresses
and city walls as they went.

And in the modern world
rammed earth buildings

are having a Renaissance.

- Rammed earth, it doesn't
exactly scream innovation

but yet it's coming back
as a building method

because of its
structural properties

and other useful properties
like its thermal mass

for controlling temperature.

It can control room humidity
at a perfect 40 to 60 degrees.

- [Greg] Rammed earth
construction techniques

are also highly
energy efficient.

- You don't need any
processing at all.

It doesn't use cement.

Doesn't use energy really
apart from the energy that's

associated with moving the
earth and tapping it down.

- [Greg] As the world
becomes ever more eco aware

demand for renewable
energy intensifies.

Power from the sun,
the oceans and wind.

And there's one settlement
in the Middle East

that has been taking
advantage of the wind

for the last 1,000 years.

Located on the barren
and wind swept planes

of Northeastern Iran
near the Afghan border

is the small
village of Nashtifan

which is keeping an
ancient tradition alive.

Perched high up on a hill,
overlooking the settlement,

some very strange
contraptions are visible.

They have been cleverly
engineered to harness

the power of nature.

- In Nashtifan
there are windmills

which are still in
use today which are

an extraordinary survival,
both of Islamic engineers,

but also going back
probably into a pre-Islamic

Persian period.

And these are not
like normal windmills,

but are basically vertical
windmills mounted on a small,

low cliff to catch the wind.

- [Greg] As with the
more famous European

windmill design, these
pioneering devices

were constructed to
grind wheat into flour.

But the design of these
windmills are thought

to date back to between the
sixth and 10th centuries,

long before they were
introduced elsewhere.

- The tradition is that
these windmills were invented

by a Persian slave working
for one of the early

Umar caliphs claim
that, you know

these were the most
extraordinary invention.

- [Greg] Each windmill
is about 65 feet tall

comprising eight chambers,
and each chamber houses

six blades.

- There was a vertical
shaft that goes down

to a subterranean mill
in which it is connected

to two millstones, which
are grinding the core.

And because the
wind is so strong

in this particular parts of Iran

it's sufficient to efficiently
keep these mills going

over long periods of time.

- [Greg] Wind power is
more important than ever

and in recent years engineers
have made great strides

in turning this elemental
force into electricity.

There are now over 340,000 wind
turbines across the planet.

From the California deserts
to the green hills of Scotland

and giant offshore farms.

At their heart some simple
but effective engineering.

- The idea of a wind
turbine is basically

that the wind moving causes
a blade to turn around

which drives the generator
and produces electricity.

- [Greg] The majority
of wind turbines fall

into two basic categories.

- A horizontal axis
turbine which has a blade

that goes like this.

It looks like a windmill blade.

And another one which is
called a vertical axis turbine

which they kind of
look like spirals

and they spin round in that
direction, so vertical axis.

- [Greg] Most commonly
turbines have three blades

and operate up-wind.

The turbine pivots at
the top of the tower

and the blades
face into the wind.

- The great benefit of
wind turbines especially

when you use lots of
them is that we prevent

carbon dioxide being emitted
and currently we're saving

hundreds of millions of
tons of carbon dioxide

by using wind turbines.

- [Greg] Wind turbines
aren't without opponents.

Some believe they
can harm wildlife

or spoil natural landscape.

Despite many years
of innovation,

by the 13th century
the Islamic golden age

was nearing its end.

With the Mongolian empire
expanding to the west,

Baghdad was sacked in 1258
ushering in a period of decline.

But other Islamic
empires were emerging.

One rising dynasty
would help turn India

into an economic and
military powerhouse.

- The Mughal empire
was founded in 1526

by the Timur prince named Babur.

- [Greg] Babur invaded
India from his stronghold

in Kabul, now the
capital of Afghanistan.

- He's a fascinating character

because he was related not
just to one famous warrior,

but to two.

He was related to
Timur, otherwise known

as Tamerlane the Great
and also to Genghis Khan.

So conquering was in his DNA.

- [Greg] The Mughals
were ambitious,

hatching grand engineering
and military plans.

Among countless projects they
transformed Jaigarh Fort,

136 miles Southwest of Delhi
into one of the greatest

cannon foundries in the world.

The fort was built with
thick walls of red sandstone

and spread over a vast
area nearly two miles long

by half a mile wide.

It was constructed in a
region with an abundance

of iron ore mines, source of
the raw material for cannon.

Mughal engineers also devised
an ingenious wind tunnel

on an unprecedented scale.

Its purpose was to draw
air from the high mountains

for use in heating furnaces.

- You needed an exceptionally
high temperature

to create these cannons.

And so the furnaces apparently
reached temperatures

up to 2,400 degrees
Fahrenheit or a 1315 Celsius.

So really, really intense
heat to create these.

- [Greg] The cannon
produced here were big,

including one of the
largest in the world.

This 50 ton 20
foot monster rests

on two massive wheels
nine feet in diameter.

Never used in war,
the giant weapon

was only once tested fired.

[gunshot]

As well as building on
all the great learnings

of Islamic engineering,
the Mughal empire

would also introduce a new
focus on architectural beauty.

Under various emperors,
they embarked on a series

of epic building projects,
constructing lavish palaces

and mosques the likes of which
had never been seen before.

It culminated in one
of the most iconic

and famous buildings on
the planet, the Taj Mahal.

Photographed millions of
times, visited by people

from across the world.

Superstars, world leaders
and royalty all have marveled

in awe at its splendor.

- The Taj Mahal is one of
the most iconic buildings

in the world.

Probably one of the
most recognizable.

It's become a symbol of
the country of India.

It is overwhelming.

It is a building that awes you.

- [Greg] The Taj
Mahal has been voted

one of the new seven
wonders of the world.

- The Taj Mahal is a
truly staggering creation.

It's particularly
wonderful because it seems

to almost come alive
when you look at it.

- The engineering of
the Taj Mahal itself

is just incredible.

But the beauty and the
serenity as you're walking

around it is the thing that
almost touches your soul.

- [Greg] However, this
masterpiece of art

and engineering is neither
a palace nor a mosque.

- The Taj Mahal was built
by the fifth Mughal emperor

Shah Jahan, who reigned
from 1628 to 1658

and he built it as a mausoleum

for his favorite
wife Mumtaz Mahal.

She died giving birth
to their 14th child

and a year later he
started construction

on this amazing monument to her.

- [Greg] Built on the
banks of the Yamuna river

in the Indian city of Agra
around 130 miles Southeast

of New Delhi, the Taj
Mahal and its gardens

cover an area of
nearly 17 hectares.

- We can certainly
consider the Taj Mahal

to be the Zenith of
Mughal architecture.

Taj Mahal translates as
the crown of the palace.

- The Taj Mahal is an
engineering marvel.

It's absolutely extraordinary.

Everything in it is perfect.

It's been conceived with a
plan, it's all symmetrical

and it is built with the
most remarkable craftsmanship

in history.

- [Greg] It was built
over a period of 22 years

employing 20,000 workers.

28 types of precious
and semiprecious stones

were used in its construction.

- It costs a phenomenal
sum of money.

Something like 32 million rupees

which in modern terms
is a billion dollars.

- [Greg] But this famous
white marble mausoleum

is not all that it seems.

- So when we at the Taj
Mahal, we are overwhelmed

with this aesthetic
of white marble,

which, you know gleams at
certain times of the day

but the building is not
actually constructed of marble.

- [Greg] Even the
grandest buildings

of this period were
constructed with red sandstone.

This would then be
hidden by an outer skin

of finer material.

- So with the Taj Mahal,
it's of stone building,

but covered in just
sheets and slabs

of this amazing white marble.

- [Greg] But the Taj also
used innovative engineering

techniques far
ahead of their time.

A recent scientific survey
revealed that the 16th century

designers may have anticipated
some potential disasters.

- The four towers which
frame the mausoleum structure

were built to just ever
so slightly lean away

from the mausoleum.

So if for some reason a
minaret was to collapse

it would not fall in the
direction of the mausoleum

but would fall away from it.

- [Greg] The monument's
location on the banks

of the Yamuna river also
presented a major challenge

to construction engineers.

- The ground around
there is soft clay

and silt is really,
really poor ground.

And the Taj Mahal is a very
dense, huge stone building

which is very heavy.

And so the foundation
construction to
stop it just sinking

into the ground was
a huge challenge.

- The foundations of
the Taj Mahal were built

using something called
a well foundations.

- [Greg] Workers
first sunk deep shafts

right down to water level.

These were lined with
ebony which wouldn't rot.

The gaps were then
crammed full of stones

with arches built above.

For nearly 400 years
these foundations

have prevented the
structure from sinking

into the soft riverbank.

- So the Taj Mahal is
a bit like an iceberg.

What you see is just at the top

but there is an immense
structure beneath the surface.

- [Greg] However, the land
directly across the river

from the Taj Mahal is the
site of further mystery.

Legend tells that following
completion of the mausoleum

to his wife, Shah
Jahan planned to build

an identical
monument for himself.

Only this mirror image
would be in black marble

instead of white.

- It's a wonderful
story and it creates

such an evocative
image but there is no

archeological
evidence to indicate

that this was ever
actually intended.

What actually happened
is when Shah Jahan died

he was taken very
unceremoniously at
night to the Taj Mahal

and he was buried there as well.

- [Greg] Shah Jahan died in 1666

and within a few decades
the Mughal empire

was sinking into decline.

But the innovation and
invention of the Mughals

and at the golden age of Islam

are still influencing
engineers to this day.

Throughout the world
new Islamic structures

celebrate the past while also
looking towards the future.

Sometimes in the most outlandish

and creative ways imaginable.

Located in the
United Arab Emirates

and inspired by the domed
roofs of ancient Islam

is the Louvre Abu Dhabi.

It costs over $100
million to construct

but its name came with
an even higher price tag.

- They actually had to
pay the French government

$500 million for the right
to use the name of Louvre.

- [Greg] This
structure's engineering

took his Islamic dome
design to new heights.

Its architect had a vision
of a dome that would appear

to float with as few support
structures as possible

to avoid interrupting
the flow of the building

- To get this design right
was a significant challenge.

They kept having to go
back to the drawing board.

23 times they had to
remodel this in order

to get the design that
worked with the lights

and with that feel of space
and serenity just perfect.

- [Greg] Four concrete
towers were put in place

to support the dome's weight.

They were ingeniously hidden
within the building structure,

vital in creating the
illusion of a floating dome.

But engineers also had to
overcome another problem.

During the heat of the
day the dome might expand

by a number of inches
before contracting

in the cool of the night.

- Essentially the building
is breathing in and out.

- [Greg] The ingenious solution
was to fit each support

with huge six ton
spiritual bearings,

ordinarily used on bridges.

- Is a kind of
curved sliding plates

which sit on top
of the supports.

And as the roof expands, it
slides over these bearings.

And as the roof contracts,
it slides back over.

- [Greg] Many modern buildings

are designed to be weatherproof,
shockproof and fireproof.

They're engineered
to take all that

the elements can throw at them.

But lacking this protection,
one of the world's

greatest Islamic structures
is now under threat.

- The Taj Mahal is certainly
losing its looks at the moment.

The city where it's built
is one of the most polluted

on earth.

The color of the white
marble is changing

from white to yellow.

There are cracks appearing
in the building itself

and the foundations are
now very, very insecure.

- [Greg] The upper
parts of the minarets

are said to be on the
verge of collapse.

When high winds struck
the Taj in 2018,

two pillars on an outer
building, fell to the ground.

Engineers are racing
to understand why

the structure is degrading.

- It's a particular
problem with the river

near which the Taj
Mahal has been built.

- [Greg] When the Taj
Mahal was constructed,

the river Yamuna was
an important route

for business and travel.

But as India's population grew
and industries flourished,

dams were built on the
river reducing its flow.

- And as the water
level has fallen

that means that the
foundations are no longer

always wet, but they
need to remain wet

to retain their
structural integrity.

If the foundations of a
Taj Mahal become too dry

they will crack and they
will not be able to support

this enormous building
on top of them.

- [Greg] But it's not
just the foundations.

- You've got local air
conditions that are actually

corrosive to the building
structure itself.

- [Greg] Measures have
been taken to help preserve

this great Islamic monument.

Vehicles are now banned from
within 1,640 feet of the Taj.

- The government has
prevented local industry

from producing the
toxic gases in the area,

but more needs to
be done to preserve

the building structure itself.

- [Greg] The Taj Mahal is
not only a landmark of India,

it's also a world heritage site.

- When we look at
the Taj Mahal today,

we're looking at a
structure and a complex

that was formulated
and built at the height

of one of the greatest empires
of the early modern era.

And it's still here.

It's still standing.

So it's a testament to the
engineers who worked on it.

It's testament to the countless
nameless who worked on it

and speaks to the incredible
initiative of these people

at the time.

It's really a wonder
of architecture.

It's a wonder of engineering
and you know, it's a marvel.

- The Taj Mahal is
so important to us

because it's such
a powerful reminder

of what could be achieved
back hundreds of years ago,

back in the 16th century.

- [Greg] The Taj
Mahal is testament

to the incredible Islamic
engineers of the past.

And today across
the Islamic world

new buildings continue to
emerge from this tradition.

Completed in 2010,
the Burj Khalifa

in the United Arab Emirates
became the tallest building

in the world and it's
design was inspired

by a ninth century mosque.

Completed in 851, The great
mosque of Samarra in Iraq

was for a long time the
largest mosque in the world.

Just like the mosque,
the Burj Khalifa

is built to a spiral
pattern design

but its Islamic influence
runs even deeper.

The Burj Khalifa was
constructed using a 20th century

technique developed by
an Islamic engineer.

- Originally skyscrapers are
built with steel structure

so that you've got
essentially pillars, columns

that are supporting the
weight of the building

as it goes up.

- [Greg] All that was set
to change in the 1960s.

- A Muslim engineer
Fazlur Rahman Khan

came up with an idea
that revolutionized

how skyscrapers are built.

- [Greg] Khan was
described as the Einstein

of structural engineering.

Instead of rigid steel
frames, his brilliant idea

was to use a tubular design.

It forever changed the way tall
buildings were constructed.

- Fazlur Khan came
up with a system

where he effectively bundled
the structure together

in a series of tubes,
which were tied together

which allow buildings
to go taller

and stay rigid and
remain slender.

- [Greg] This
engineering technique

meant that skyscrapers such
as the Sears Willis Tower

in Chicago no longer had to
stick to a dull boxy form.

- So the outside is
actually the structural part

of the building that
holds the strength

of the materials itself.

So it means that
you can build high

because the taller you build
the more structural stability

that you've got
supported by the skin

of the building itself.

- [Greg] Khan's innovation
may not have come in Islam's

golden age but it has
allowed buildings in cities

throughout the world
to reach ever higher.

Since Islam seventh century
origins in the Middle East,

the creativity of
its engineers led

to countless innovations.

During the golden age, their
work touched all aspects

of life.

The legacy of their early
buildings and innovations

has influenced
generations of engineers.

They also created one of the
most beautiful structures

on the planet and their
breakthroughs helped the world

build ever bigger
and ever taller,

changing cityscapes forever.

[dramatic music]