All language subtitles for Ancient.Engineering.S02E06.1080p.AMZN.WEB-DL.DDP2.0.H264-chr00t_track3_[eng]

- [Narrator] The world's
greatest structures,

push the boundaries
of engineering,

all fueled by a constant
desire to innovate.

- Without engineering there
would be no modern world.

- [Narrator] Gigantic buildings,

complex infrastructure
and ingenious inventions.

- Engineering is the key that
turns dreams into reality.

- [Narrator] Many of today's
incredible achievements

rely on breakthrough
technologies

first devised by
ancient engineers.

- It's astounding how
they achieve this.

- [Narrator] Early civilizations

built on an unimaginable scale,

and with incredible precision.

- They raised a
bar for engineering

in a way that no one
thought possible.

- These are some of the
finest engineers in history.

- [Narrator] Redefining
the known laws of physics,

and dreaming up the impossible.

They constructed engineering
wonders from colossal stadiums,

to mighty waterways
and complex machines,

all with the simplest of tools.

- You cannot imagine the skills

people would have needed
to build like this.

- [Narrator] By unearthing
the mysteries left

by these ancient engineers,

we can now decode their secrets.

- That so many of their
creations still survive

is testament to their
engineering prowess.

- [Narrator] And, ultimately,
reveal how their genius

laid the foundations for
everything we build today.

(dramatic music)

Home, a place that fulfills
our most basic needs.

- Since humans have
formed in groups,

we've needed to
have a safe place.

- It's where we belong.

- [Narrator] An immediate
need for sanctuary

has propelled the
human race to create

evermore extraordinary homes.

- What a house is and what it
looks like and how it's built

it has changed
enormously over time.

- And throughout all of this,

engineering has
played a key role.

- [Narrator] Today, the
construction industry

is worth 10 trillion
dollars annually,

and employs 7% of the
world's workforce.

And the house has transformed
from a place of refuge

to a space filled with every
cutting edge convenience.

- Today, we have houses that
really are so sophisticated,

so advanced.

- We've gone from a cave
to the most beautiful,

and extraordinary
and intelligent
buildings ever created.

- [Narrator] But the comfort
and safety of the modern home

has only been possible through
the grit, determination,

and engineering ingenuity
of our ancestors

in the ancient world.

(dramatic music)

Life was harsh for our
earliest ancestors.

Constantly on the hunt
for their next meal,

they lived a
transitory existence,

so finding a permanent place
to live wasn't a necessity.

- You start off by living
in what nature provides,

in the overhang of a
rock, or in a cave,

or under a comfortable tree.

- There was no such thing
as a permanent dwelling.

They were constantly
on the move.

- [Narrator] Around
100,000 years ago,

many of our
Neanderthal ancestors

would've moved from cave to
cave in search of shelter,

or refuge from predators.

The earliest shelters
built by humans

were structures with a
frame of wood or bone,

and a covering of animal hide,

but then around 12,000
years ago came an advance

that would change not
just our ancestor's homes,

but the entire way of
life for humankind.

The dawn of agriculture.

- Agriculture meant humans
were able to stay put,

and produce what they
needed in terms of food,

to be able to survive
in a single place.

- That's the point at which,
certainly, there's a sea change

in the way we think
about our houses.

(dramatic music)

- [Narrator] The
planet's new farmers

remained in one
location all year round,

and they needed a dwelling
that provided security,

and shelter no matter
what the season,

and 7,000 years ago
across swaths of the globe

from North America
to Northern Europe,

they began to create enormous

multifunctional wooden
structures called longhouses.

- The longhouse is
a very effective way

of really entertaining
both your family,

and your extended family.

These are palatial
structures, okay?

These are things that are
being commissioned by elites,

so the longhouse
becomes in many ways

an articulation of your power.

- [Narrator] The largest
freestanding structures

of the Neolithic Era,

longhouses could be
up to 165 feet long.

And building them took not
only skill, but ingenuity.

It's probable that
large wooden poles

were driven into the ground at
depths of around three feet,

and held in place by a
slotted wooden timber

called a sill beam,

before being packed
tightly with soil.

Horizontal planks fastened
the parallel walls together,

creating a strong frame
with a load-bearing capacity

to support a large roof
of thatch or grass.

- Longhouses give us a scale
that we haven't seen before.

Some of them are
absolutely enormous,

ceremonial, almost certainly,
and communal as well.

- [Narrator] Built to
house up to 30 people,

it wasn't just their enormous
size and solid structure

that set longhouses apart.

Their walls were made using
a new building technique.

Instead of utilizing animal
hides as early shelters had,

they were constructed
with the wonder material

of the Neolithic
Age, wattle and daub.

- Wattle and daub is
very, very simple.

You take cut hazel
wood or willow wands,

and you weave those to create
in essence a sort of mesh

against which you
then press a daub,

which is comprised of
clay, dung, and straw.

- [Narrator] Replacing the
animal hide covering of the tent

with a thick clay wall
of wattle and daub

represented a step change
in the comfort of the house.

- It has fantastic
powers of insulation.

It's as simple as that.

And as a consequence of that,

that we see it being used in
structures all over the world.

- [Narrator] The
Neolithic longhouse

was adapted by
later civilizations,

including Native
Americans and Vikings,

and remnants of those buildings,

like this site of a ninth
century Viking longhouse,

are testament to the
longevity of the design.

- They evolved there
from the Neolithic,

all the way through
into the sort of

seventh, eighth,
ninth centuries,

certainly across
Northern Europe.

The longhouse worked
for centuries,
centuries and centuries.

- [Narrator] It is a classic
example of how our ancestors

used what was at hand to
make a more permanent home,

but even when basics like mud
and wood weren't available,

humans have used engineering
ingenuity to construct a refuge

from the most unlikely
building materials.

The Arctic.

A vast mass of ice and snow
centered around the North Pole.

Temperatures here can plummet

to below minus 65
degrees Fahrenheit.

It's hard to imagine a more
unforgiving environment.

And yet this frozen landscape

is home to one of the
world's most ancient,

and most resourceful
house builders.

The Inuit.

- Inuits have lived
in the Arctic region

for about the last 5,000 years.

And they developed this
ingenious structure

without any stone available,
or even mud to make bricks,

or trees to make beams from.

- [Narrator] All that
surrounds them is ice and snow.

And from it, the
Inuit created one of

the most iconic
shelters ever developed.

The igloo.

Built as temporary
shelters for hunters,

as they crossed immense icy
wastelands in search of food,

the Inuit have made
igloos for centuries,

possibly millennia,

using nothing but the frozen
material surrounding them.

- The classic way
to build an igloo

is to have three lower
courses in ice blocks.

That gives you a very
solid foundation.

Then you have lighter
compacted snow,

and you build that in a spiral
form, so there's no weakness.

It's only, in fact,

one course that winds its
way around right to the top.

- [Narrator] The true
genius of the igloo's design

is the way the Inuit engineered
it to be both stable,

and self-supporting.

The secret of its
success, its shape.

- The shape of the igloo is
based on a catenary arch,

which is the most
stable arch in nature.

- If you imagine holding
a chain at two ends,

and let it fall freely,

it will produce this
perfect catenary shape.

And if you invert
that and flip it up,

then you get a catenary arch.

- [Narrator] The catenary arch
is extraordinarily stable,

and strong because the vertical
force of gravity on the top

is distributed evenly
through the center line

of the walls below.

Therefore, each course
in the structure

holds the weight of
the wall above it.

- It's one of those
amazingly sort of

beautiful natural solutions.

You get this art shape

that can completely
withstand its own weight,

and creating that catenary
shape for an igloo

means that it's very resistant
at wind pushing against it,

snow pushing against it.

These elements actually end
up compressing it slightly,

and, therefore, making
it even stronger.

(soft music)

- [Narrator] The Inuit perfected
the igloo over centuries,

but they didn't just build

with structural
stability in mind.

They also achieved the
seemingly impossible,

creating a warm
shelter from icy snow.

- Snow is about 95% air.

And that means that
it is insulative.

So if you can create
an enclosed environment

with blocks of hardpacked snow,

then the temperature inside
can be very different,

much warmer than
what it is outside.

- [Narrator] The
extraordinary heat retention

inside the igloo is
all down to its clever,

and distinctive design.

Built to exploit the
fact that warm air rises,

and colder air falls the
interior is terraced.

The warmest spot
is the top level,

kept heated by the
air rising from a fire

on the middle terrace.

As the warm air reaches
the upper part of the igloo

it cools down
falling to the bottom

where it sits on the lowest
level which acts as a sump.

In this way, temperatures inside

can be over 100 degrees
Fahrenheit higher than outside.

- And once people are inside
whether from their body heat,

or lighting a fire,

the inside of the igloo
can melt slightly,

and as it refreezes

it creates a thin shell
of ice on the inside

that makes it stronger still.

- [Narrator] The
Inuit took advantage

of the characteristics of snow

to create an unlikely
place of warmth and safety

in one of the most hostile
environments on Earth.

- The igloo really is a
mini engineering marvel.

It is so ingenious
in its simplicity.

- It's a classic example
of human ingenuity

in going to a
hostile environment,

and seemingly having nothing
familiar with which to build,

and yet triumphing by
working with the environment

rather than against it.

- [Narrator] The
product of the Inuit's

inspired engineering, the
igloo allowed them to hunt,

and, therefore,
survive all year round.

It's such a monumental
accomplishment

that it took cutting
edge modern engineering

to achieve a similar feat at
the other end of the world.

(dramatic music)

Antarctica, the planet's
Southern polar region,

the coldest, driest, most
wind-swept place on Earth.

Temperatures here can be
50 degrees Fahrenheit lower

than in the Arctic.

- Antarctica is one of the most

unforgiving places
on the planet.

You've got 100
mile an hour winds,

and the sun does not come
up 105 days of the year.

We're talking harsh conditions.

- [Narrator] But
for over 50 years,

scientists from the
British Antarctic Survey

have been conducting
vital research here

into how our planet works,

and the impact of climate
change on the polar ice cap.

Their current research
station, Halley VI,

is located on an ice shelf
that is over 400 feet thick.

It's arguably the most perilous
place on Earth to build.

- It's a floating piece of ice,

which is heading towards
the sea and that can crack,

so at any moment the
ground could open up

swallowing the research
center and everyone inside it.

- [Narrator] How can
engineers create a structure

that can survive in this
precarious landscape?

The answer lies in
Halley's adaptable design.

- Halley VI is made
from modular pods.

So it can break up into
these smaller pieces.

- Then that means that if
there is a sign of danger,

it can be moved quickly.

- [Narrator] After almost five
years of successful operation

Halley VI faced the
ultimate challenge,

when a crack in the ice
came too close for comfort.

- The research
center was at risk.

They had to act fast and move it

to avoid it being lost entirely.

- [Narrator] A widening
crack in the ice shelf

meant that Halley VI,
and its residents,

were in danger of being
swallowed up by sea ice,

but the weight of each pod

could create additional
destabilizing
fissures in the ice.

So to ensure a safe
and speedy getaway,

engineers had equipped each pod

with hydraulic legs
mounted on large skis.

- You need to be able to
lift the research station

out of the snow to
be able to move it.

And with these hydraulic legs,

you can lift the whole
research station up,

and out of that danger zone.

- What the skis do is allow the
station to be dragged along.

And remember this
is a big building,

so the skis beneath it help
to spread the load on the ice,

which could crack at any time.

- [Narrator] Using tractors
to tow them across the ice,

it took 13 weeks to move the
eight pods 14 miles to safety,

a feat only made possible

by the station's
groundbreaking design.

- The fate of Halley I
to V was that essentially

those research stations were
sacrificed to the elements,

and Halley VI with all
its ingenious features

is still going strong today.

- That means that the scientists

can continue their
important research

in one of the most hostile
environments on this Earth.

- [Narrator] Population
projections predict
that by 2050,

there could be as many as
2.5 billion extra people

living in urban areas worldwide,

turbocharging the demand for
housing across the globe.

The cornerstone of
this building boom.

The humble brick.

1.5 trillion of them
are produced every year.

That's almost 200 bricks

for every man, woman,
and child on the planet,

but the basic building block
of 21st century urbanization

at its genesis in
the ancient world.

(dramatic music)

The Jordan Valley,
a sunbaked landscape

that follows the course
of the Jordan River

from the Sea of Galilee
to the Dead Sea.

Here, some of the
oldest known bricks

believed to date back to 7000 BC

were found near the
city of Jericho.

They were made from
mud that was dried

in the searing heat of the sun.

- When people came up with
engineering solutions,

in this case to build houses,

they'll use the materials
which is at hand.

So more often than not, if
you're in the hot Middle East,

you'll use mud because
it was available,

and you just shape the
bricks out of the mud.

Later you'd use a mold,

and it will be left
in the sun to harden.

- [Narrator] Entire cities
like fifth century Yazd

in Central Iran were
constructed from mud bricks,

but they were a weak
building material

because even after drying
they retained moisture.

- How do you make the brick
made of mud or clay harder?

You fire it in an intense heat.

- [Narrator] By
heating them in a kiln

to between 300 and 1,200
degrees Fahrenheit,

bricks lose all their moisture.

When temperatures exceed
1,600 degrees Fahrenheit,

chemical compounds melt to
form tiny quantities of glass,

which bind the molecules
of clay tightly together

in a process known
as vitrification.

- What happens is in
essence when it's cooled

that has in effect turned that
brick into a form of stone.

- [Narrator] The Chinese first
developed kiln fired bricks

around 3000 BC,

but it was one of the
greatest civilizations

of ancient Europe that produced
them on an industrial scale.

The Romans.

- Bricks are made
literally by the million

in brickyards outside Rome
and other major Roman cities.

They take a technology
that had been around

for thousands of
years, the brick,

and really put rockets under it.

- [Narrator] The ability
to mass produce the brick

changed the home for good,

but as its empire expanded,

Roman builders faced
an enormous challenge.

A rapidly growing population
needed new houses,

and they needed them fast.

At its peak around 100 AD

the Roman Empire stretched from
Britain in Northwest Europe

to Egypt in Northeast Africa

covering an area of 2.3
million square miles.

And it's likely that the
population of the city

at its heart, Rome,
topped one million.

- These are all people
who've got daily jobs

who play an intrinsic part of
the working of Rome itself.

So they've got to
live somewhere.

- [Narrator] The challenge
was to accommodate them

in affordable housing within
a relatively small space.

Building out wasn't an
option, so they built up.

- Why do you build upwards?

It's because land is expensive.

So you stack more floors
above your bit of city land,

and people start to
live in multi-story

vertical apartment blocks.

- [Narrator] Known as insulae,

the blocks were usually built
over five or six stories,

and consisted of six
or seven apartments,

housing up to 40 people.

- There'll be some shop fronts.

There would be apartments
over the shop fronts,

not quite like downtown
Manhattan, but not
far off of that.

- [Narrator] Insulae were
constructed at breakneck speed.

Thanks to the ready availability
of mass produced bricks,

and one other vital ingredient.

Concrete.

- The Romans weren't the
first people to use concrete,

other people used it
before the Romans,

but they refined the technique.

It was a real turning point
in the way that the Romans

built their houses.

- [Narrator] Concrete
is an easy-to-use,

yet durable building material.

The Romans began to work
with it from around 300 BC,

and extraordinarily some
of it still survives today.

- The key thing which
made Roman concrete better

than anything that had gone
before was that it contained

a new ingredient, volcanic ash.

- [Narrator] Concrete
is made of water,

sand, gravel, and cement,

which binds the other materials
and hardens over time.

Adding volcanic ash, or tephra,

and solidified lava
in place of cement,

made Roman concrete
remarkably durable.

As lava from a volcano cools,

glass and crystals
form within it.

These crystals react with
hydrated lime in the tephra

to
form
calcium-aluminum-silicate-hydrate,

which acts as a binder that
glues the concrete together,

making it stronger
and more resilient.

- What you've got is something
that sets as hard as stone.

- [Narrator] Versatile and
relatively easy to produce

without concrete
the Roman insulae

would never have been
built so quickly.

- It streamlined the house
building in the Roman world.

Instead of having to
extract stone remotely,

you could actually make
the concrete on site.

So it was there and it was
quicker and faster to use.

- It's like the Henry Ford
of building materials, right?

You can turn it almost
into a production line.

It's a strong, durable,
cheap, brilliant substance.

- [Narrator] Mass produced
bricks and concrete

allowed the Romans to build
houses at an astonishing rate,

but four protective walls

would be nothing without
the shelter of a roof.

And just like
bricks and concrete,

the kiln fired tiles topping
the homes of the Roman Empire

were developed from concepts

borrowed from other
civilizations.

- The ancient Chinese
were the first

to kiln fire roof tiles, and
that's from around 3000 BC.

And if you jump ahead in time,

and you move to
the Mediterranean
world by say 500 BC,

you find that the ancient Greeks

had a really interesting system

of interlocking tiles
for their roofs.

- [Narrator] The system was
known as imbrex and tegula.

The tegulae, flat
tiles with raised sides

were placed in horizontal rows.

The adjoining edges
were then covered

by semicircular imbres tiles
and mortared into place.

- The advantage of using the
imbrex half pipe curved tile

means that the water is gonna
run easily off the roof.

- The rain bounces off
the semicircular tiles,

flows down into the troughs,

and taken on down
towards the gutter.

So they developed this quite
clever interlocking system

that means there's no
holes, or gaps, or cracks

that rain can get into.

- [Narrator] Roman
house builders

took the Greeks roofing system,

and just as they did
with bricks and concrete,

they supersized it.

- They mass produced the
tegula and imbrex tiles

on a scale that we would
recognize as industrial today.

- [Narrator] The Romans
perfected the concepts

of older civilizations to
mass produce bricks, concrete,

and imbrex and
tegula roof tiles,

revolutionizing house
building forever.

- It's allowed them to build
houses on a huge scale,

making them accessible

for far more people
across the empire.

- What they achieved
was truly extraordinary.

And that house
building technology
was absolutely central

to the success of that empire.

- [Narrator] From the
moment our ancestors

first sought shelter in caves,

humans have needed to
feel safe and secure

in the place they call home.

- In the past houses have
been protected by animals,

guard dogs, by higher
walls, and also by moats.

- [Narrator] Today, there's
one device we all rely on

to keep the doors, gates, and
windows of our houses secure.

The lock.

But the key to the high
tech security devices

that protect our homes is
to be found millennia ago.

(dramatic music)

Ancient Egypt.

A highly sophisticated
civilization

that lasted three millennia,

and gifted the world the most
iconic monument of antiquity,

the Pyramids of Giza.

Still standing over 4,000
years after construction,

they are an enduring symbol

of the Egyptians
engineering brilliance,

but the accomplishments
of that era

weren't limited to
monumental structures.

The Egyptians also took
great strides forward

in mathematics, medicine,
art, and literature,

and they even found time
to perfect the lock.

- The earliest lock dates
back to the Syrians,

which is what is
modern-day Iraq,

but then the Egyptians
took that further,

and advanced that technology
in now what is known

as the Egyptian lock.

- [Narrator] Early locks were
simply a bolt across a door

released from outside
through a hand-sized opening.

What set the Egyptian
version apart?

It was one of the first
locks to use a key.

The upper part of
the lock casing

had a series of movable pins.

When the bolt was
moved into place,

the pins would fall down
into holes in the bolt,

holding it firmly
and locking the door.

To unlock an angled key was
inserted in a slot in the bolt.

The key had pins,

which exactly matched
those in the lock casing,

so that when the key was tilted
upwards it lifted the pins,

releasing the bolt and
unlocking the door.

- What it did require
was some very skilled,

and precise use of tools

to be able to get those
pins to align perfectly,

and, therefore, unlock.

- [Narrator] In the
Egypt of antiquity,

wooden pin tumbler
devices were widely used

to protect palaces and sites
of religious importance.

And they are still in
use today in Egypt,

Zanzibar and India,

but back in ancient times,

it was the Romans who
unlocked the true potential

of the Egyptian's idea,

manufacturing locks from metal

with more complex
mechanisms and keys.

- It's common to find these
keys at Roman dig sites.

And they look very similar
to what we would use today.

- [Narrator] But our
modern locking systems

don't just look like they're
ancient predecessors.

They also operate in a
remarkably similar way.

- The old cylindrical
pin tumbler system

that the Egyptians
invented was the basis

of Linus Yale's lock, which
he patented in the 1860s,

which is the one that
many of us use today

to get through our
own front doors.

- [Narrator] Today,
electronically
controlled smart locks

released by cell
phones, fingerprints,

or even face recognition
deliver personalized security,

literally, to our front doors.

All of this is achieved
without a physical key,

making it the most seismic
shift in home security

since the ancient Egyptians
invented the pin tumbler lock,

3,000 years ago.

The concept of what
makes a house a home

has developed over
the millennia.

From basic caves and
rudimentary shelters

through to solid
constructions of first wood,

and then bricks and concrete,

the human race has
grown to expect

increasing levels of comfort,

and amenity from the
buildings we call home.

Today, our houses are as varied

as the people who live in them,

but large or small,
contemporary or traditional,

they all utilize one
incredible material.

Glass.

- Glass made homes
what they are today.

To be able to see out
and allow the light in

that really transformed
our home spaces.

- [Narrator] Glass
is an amorphous solid

with an unusual
molecular structure.

It doesn't have the rigid
crystalline makeup of a solid,

but molecules aren't
as loosely arranged

as they are in liquids.

And because of this
quirk in its makeup,

it's an extraordinary
building material.

- Glass is a
wonderful substance.

At high temperatures it's
incredibly versatile and liquid,

and you can pull it
and you can stretch it,

and make it into any
shape that you want.

Then as it cools it
is strong enough,

rigid enough to hold its shape.

- [Narrator] Made by
melting the silica in sand

at very high temperatures,

glass is a mainstay of
modern-day house building,

but it's origins lie way
back in centuries past.

Ancient Egypt was one of
the first civilizations

to produce manmade glass,

thanks to its ready
supply of raw ingredients.

- What you basically
need is sand,

and then you need soda, or
something to act as a flux

to lower the melting
point of sand.

Egypt and Mesopotamia

is where those materials
were available,

and that's when
it first appears.

- [Narrator] Early
glassmaking was small-scale

producing nothing
more than beads,

but when the Romans conquered
Europe and North Africa,

they had the skill
and vision to grasp

the true potential of
glass as a raw material,

using it to create
vases, jars, and bowls.

They even stretched lumps of
molten glass to make windows

bringing something
new to the home.

Light.

- Roman houses generally
had quite small windows,

but once they got confident
in making glazed windows,

they could light
up interior spaces.

- [Narrator] These early
windows cast new light

on what a home could be,

but it was difficult to see
clearly through thick panes

handcrafted from lumps of glass.

By the fourth century AD,

the Romans realized
that using blown glass

made much clearer windows.

- Blown glass had been
around for a very long time.

They'd been blowing glass
for 300 years by then.

So it wasn't a sort
of technological leap.

It was the putting
together of the ideas.

- [Narrator] To
make window panes,

the blown glass was
shaped into a cylinder.

The top was sliced off and
a crack made in the side.

The result was a
curved form of glass,

which was then briefly
reintroduced to the furnace

where the heat softened
it allowing it to flatten

to form a thinner,
clearer pane of glass.

- When you looked
out of the window

in the early Roman period
you'd just see shapes.

You wouldn't be able
to see any details.

If you were looking through one
of the cylinder blown panes,

you'd be able to see
much more detail.

- [Narrator] At the
dawn of their empire,

no one had window panes,

but thanks to the efficiency
of Roman infrastructure,

and mass production,

glass windows became a common
feature of their houses.

- Townhouses had windows.

Great luxurious villas
they had windows as well.

So people were really
adopting this technology.

- [Narrator] The
Romans did create

colored glass vases and jars,

but their windows were made
from almost colorless panes.

It wasn't until 700 years
after the fall of Rome,

that the potential of
stained glass windows

was fully realized.

Medieval churches and
monasteries across Europe

were bathed in light from
their colorful panes.

And it's possible that builders
inspired by their beauty

began introducing
glass windows to homes,

but the enormous plate
glass common today

was only made possible by a
feat of engineering brilliance

in the 20th century.

Today, it's possible
to manufacture
enormous window panes

of up to 55 feet.

- Glass can do all
sorts of things now,

so it really is an artistic
and an architectural tool

that can be used in
all sorts of ways

to very dramatic effect.

- [Narrator] The incredible
versatility of glass

in the modern home
wouldn't have been possible

if it wasn't for one
manufacturing breakthrough.

The float glass process.

Developed by British Engineer,

Alastair Pilkington
in the 1950s,

it uses extremely
high temperatures

to create incredibly flat glass.

- The glass has to be heated

to about 3,000 degrees
Fahrenheit in order to do this.

And it allows huge sheets
of glass to be made.

So it was an absolute
technological breakthrough.

- [Narrator] The
hot liquid glass

is poured continuously
from a furnace

onto a shallow
bath of molten tin.

Stable in liquid form at
very high temperatures,

it provides an even surface,

and the glass floats on it
like oil floats on water

to form flat panes.

After controlled cooling,
known as annealing,

the glass emerges as
a polished product

with virtually
parallel surfaces.

- This process can
allow us to control

the thickness of the glass
down to 100th of an inch.

- [Narrator] Using the
float glass method,

a plant can produce

over three and a half thousand
miles of glass every year.

And adding chemicals
to the molten mixture,

or allowing it to
cool more quickly

can produce glass of
different colors and strengths

making it an endlessly
versatile building material.

- Glass brings so much to our
homes today in terms of light,

and warmth and comfort.

And yet this was started
off by that Roman idea

of bringing glass
windows into the home.

(upbeat music)

- [Narrator] One of the
hallmarks of the modern house

is the high-level of sanitation

provided within its four walls.

Living in a home
without running water,

and flushable toilets
in the developed world

is almost unthinkable
in the 21st century,

but the seeds of this
engineering triumph

that we take for granted

were sewn by one of the great
civilizations of antiquity.

(dramatic music)

Crete.

One of the largest islands
in the Mediterranean,

and home to one of Europe's
most ancient civilizations,

the mighty Minoans.

- Minoan society was
incredibly civilized.

And what it does is it controls
all of the sailing routes

around the Mediterranean,

and as a consequence of that
becomes an incredibly wealthy,

and sophisticated civilization.

- The Minoans were renowned
for their engineering.

Their crowning achievement is
the royal palace at Knossos.

Built around 1700 BC,

it's regarded as
Europe's first ever city.

- It's quite extraordinary

that they actually
managed to design,

and then build this
in the Bronze Age.

- [Narrator] In summer,
Crete has almost no rainfall,

but three and a half
thousand years ago,

the genius of Minoan engineering

made it a comfortable
place to live.

- Water management is
absolutely crucial.

And the ancient Minoans

were one of the
earliest civilizations

to come up with a
working solution.

- [Narrator] Precious
rainwater from roofs,

and the overflows from
above ground cisterns

was carried down through
buried drains of pottery pipe

into underground storage tanks.

- Their water management systems

were examples of exceptional
engineering so skilled

with designing
and building these

that some are
still in use today.

- [Narrator] This
expertise meant Minoans

had water supply to their
houses throughout the year,

even in the bone
dry summer months,

but they were also the
first known civilization

to engineer another
home convenience.

- I think for us in
the modern world,

what we're really looking for

in terms of water
management system

is the ability to flush away
certain unwanted substances.

And I think it's fair
to say that the Minoans

did come up with the first
form of flushing toilet.

- [Narrator] The Minoan toilet
consisted of a wooden seat,

and earthenware pan.

Water was poured through
a hole in the floor

immediately outside
the toilet door,

while an under floor channel

linked the hole with
the vertical clay
pipe under the seat,

and into a system of sewage
pipes outside the property.

The forerunner of the
toilet as we know it today,

the water closet was invented
in England in the 1590s,

but incredibly the
Bronze Age version

was improving the homes,

and lives of Minoans
3,000 years earlier.

- This really is hydrology
coming up face-to-face

with civil engineering,

and producing a system
of water management

that is incredibly
sophisticated.

- [Narrator] A need to keep warm

was one of the primary impulses

that drove our
earliest ancestors

to build shelters and houses,

and on the journey
from cave fire

to the automated modern
heating we enjoy today,

there have been many
monumental breakthroughs.

One around 200 BC delivered
new levels of home comfort

to well-off Romans.

- The Romans liked
their creature comforts,

and they enjoyed heated
buildings in the winter.

- So they actually
create an incredible

central heating system.

- [Narrator] The Romans
ingenious innovation

was an early form of
underfloor heating,

known as a hypocaust.

The heat source was a
wood-burning furnace

positioned just
outside the house.

Heat from it was
directed through pipes

into a cavity
underneath the floor,

which was held up by stacks
of bricks know as pilae.

Hollow tiles called box flue
tiles built into the walls

created a flue which
drew heat upwards

to warm the higher
floors of the house.

- The hypocaust is
clever engineering

because instead of just
huddling around a campfire

warming your hands,

the heat of that
fire is transported,

and distributed
throughout the building.

- [Narrator] A major
technical achievement,

the hypocaust is an important
engineering milestone

in the development of the house,

heralding a new era of
comfort for well-off Romans.

- It marks another step of
sophistication and innovation.

It allows you to have all
the benefits of heating

without actually the
mess and noise and smoke,

and sort of a fire
in your living space.

- So it's making the house

a much more pleasant
environment to live in.

- [Narrator] The hypocaust

is such a brilliantly
designed piece of engineering

that after the fall
of the Roman Empire,

there was no comparable
central heating system

anywhere in Western Europe
until the 20th century,

but vast areas of
the ancient world

didn't have to battle with
biting cold, but scorching heat.

Iran.

With evidence of
human settlement

dating back over 100,000 years,

it's probably one of the
oldest inhabited regions

in the world.

- The civilizations that lived
in Persia, modern-day Iran,

have been hugely influential
in the history of mankind.

- Incredible developments
in innovations,

in terms of engineering,

but also art and culture

really were inherited by
the modern state of Iran.

- [Narrator] Summers in this
ancient arid land are long,

and temperatures
regularly sore above

100 degrees Fahrenheit.

- The country of Iran has a
massive central desert plateau,

and that makes it
incredibly hot.

And the people who live there
really needed to find a way

that they could live in this
very difficult environment.

- [Narrator] Thousands of years
ago, Persian house builders

were among the first to
hit on an ingenious way

of keeping homes cool
in the desert heat.

The wind catcher.

- Wind catchers are tall,
striking chimney-like structures

that can be seen
protruding from old houses

throughout modern-day Iran.

- In these hot, dry flat
areas, you will get winds,

you will get breezes.

And what you're doing
with a wind catcher

is catching that wind,

channeling it down
into your building,

so that you're cooling
your inside spaces.

- [Narrator] The
earliest wind catchers

dating back millennia
come from both Egypt,

and ancient Persia.

At its simplest,

open vents facing towards
the prevailing wind

draw cool air down the
chimney of the wind catcher.

Once inside this air passes
over an indoor pool cooling it.

This cooler air then displaces
the warmer air in the house,

sending it back up the
tower of the wind catcher,

and exhausting it
outside the building.

- Moving air and water
are both coolants,

so that transformed the
sense of living within a box

of still dead hot air
into something much more

like sitting next to
a stream with a fan.

- [Narrator] Centuries
old wind catchers

have been shown to reduce
indoor temperatures

by almost 20 degrees Fahrenheit.

- I just think it's an
amazing piece of technology.

The Iranian wind catcher

is the original air
conditioning unit.

- [Narrator] Wind
catchers are so effective

that they even helped
keep the Persian ab anbar,

domed underground drinking
water reservoirs almost ice cold

as outside temperatures

rocketed above 100
degrees Fahrenheit.

- Wind catchers are genius
because they're passive.

They require no energy.

There's no moving
mechanics there at all.

It's simply harnessing
nature to human advantage.

- [Narrator] Today in hot
arid areas of the world,

cooling systems account for 60%

of total building
energy consumption,

but wind catchers with
advanced technologies

designed to meet the
needs of the 21st century

could help cut energy use,

while leaving little
or no carbon footprint.

Could effective engineering
solutions like this

be the future of housing?

Some of the most alarming
climate change modeling

predicts that by the
end of this century,

the world will be nine
degrees Fahrenheit hotter

than it was in
pre-industrial times.

And as our planet gets warmer,

cities are set to really
feel the rise in temperature.

That's because buildings
and roads absorb,

and re-emit the sun's heat

more than the
natural environment,

creating a phenomenon known as
the urban heat island effect.

- The urban heat island effect

can make metropolitan areas
up to 22 Fahrenheit hotter

than more green spaces.

- [Narrator] Research predicts

that the influence of the
urban heat island effect

will only get stronger as
the global population grows.

So how do we cool our cities
without energy hungry air con?

One solution is to
go green, literally.

This is One Central Park Sydney.

At over 350 feet the larger
of its two tower blocks

is covered in over 35,000 plants

making it the world's
tallest vertical garden.

- What the plants do
is they absorb the heat

rather than having that heat
bounce off from concrete

onto a pavement and be
trapped in the city.

- The plants on the
outside of the building

also act as insulation.

It cools the
apartment in summer,

and keeps it warm in winter.

- [Narrator] The vegetation
even helps reduce

the temperature in the
environment around the building.

Hundreds of tower blocks like
this could have the potential

to combat the urban
heat island effect

by helping to cool
down entire cities,

but its vertical
garden isn't the only

innovative eco-friendly
element of these apartments.

- The most striking
feature of this building

is a huge platform jutting
out from the top tower.

- It's almost like an
upside down dance floor

in between the two buildings.

- [Narrator] The platform
which juts out almost 140 feet

from the 28th floor of
the taller tower block

is part of a heliostat system

designed to redirect light to
shaded areas of the complex.

- Light from the sun is bounced
from mirrors on the roof

of the smaller tower up
to 320 reflective panels,

which then directs that
light down onto the ground

in the space between
the two towers.

- [Narrator] It's
stunning vertical garden,

and groundbreaking
heliostat system

make Central Park
Sydney a world first.

- This is high-rise living

with solutions to cut
down the carbon footprint.

It's the future of the house.

- [Narrator] By the middle
of the 21st century,

the world's population is
said to reach 9.8 billion.

- This will throw up
enormous challenges

for the engineers of today to
create our homes for tomorrow.

- How do we build
cheaply and efficiently,

and environmentally responsibly

to accommodate that
number of people?

- [Narrator] And the
challenges in engineering

our future homes
don't stop there.

- We now live in a world

which is colored by
extremes of weather.

- We see floods in Europe.

We see hurricanes sweeping
across the United States.

We have to rethink our houses.

- [Narrator] As we
step into the future,

what we build and how we
build it will be transformed.

- There are
substantial challenges.

We have to build things which
are protected against flood,

and fire and heat.

- So we need to build smarter,

and use more innovative
materials and processes.

- And it's engineering that
will help us to redefine

how we accommodate ourselves,

how we learn to live and
adapt in this changing world.

- [Narrator] As the
engineers of today

face the challenges
of the future,

they are fired by
the innovative ideas,

and the incredible vision
of their predecessors

in the ancient world.

(dramatic music)