Nova (1974–…): Season 35, Episode 10 - Secrets of the Parthenon - full transcript

Nova checks in to see how the multi-decade restoration of the Parthenon is going. They find the restorers dealing with a massive jigsaw puzzle with pieces that are only slightly different, many of which are broken or missing, and the remaining pieces were reassembled wrong by the last restoration team. Even modern methods are not up to the challenge of reconstructing the missing pieces with the necessary precision so it is necessary to rediscover the ancient methods.

Are you wondering how healthy the food you are eating is? Check it - foodval.com
---
NARRATOR:
It is the Golden Age of Greece,

a unique window of time that
gives birth to Western ideals

of beauty, science, art,

and a radical new form
of government-- democracy.

To immortalize those ideals,

the Greeks build
what will become

the very symbol
of Western civilization--

the Parthenon.

JEFFREY M. HURWIT: It was
the physical embodiment of their values,

their beliefs,
of their ideology.

It remains for us
a powerful statement



of what human beings
are capable of.

NARRATOR: But today, solving the secrets
of how the ancients designed

and engineered the Parthenon
has taken on a new urgency...

(explosion)

For after 2,500 years of being
ravaged by man and nature,

the building is in danger
of collapse.

(speaking Greek)

NARRATOR:
Hidden behind its columns,

a rescue mission is under way.

The team must take apart, repair
and reassemble

tens of thousands of its pieces.

And although
the Parthenon appears

to be geometrically straight

and made
from interchangeable parts,



subtle curves
make each piece unique,

varying by fractions
of a millimeter.

The quality
of the engineering work

and the precision is unmatched
even from us today.

NARRATOR: The restoration team
has taken over 30 years

and spent well over $100 million

restoring what
the ancient Athenians built

in just eight or nine years.

It is clear today's technology
can only take the team so far.

To rescue the Parthenon,
these modern architects,

stonemasons and archaeologists

must unlock the engineering
secrets of the ancient Greeks.

Up next on NOVA:
"Secrets of the Parthenon."

Major funding for NOVA
is provided by:

And:

Additional funding
for "Secrets of the Parthenon"

is provided by:

Major funding for NOVA
is also provided

by the Corporation
for Public Broadcasting

and by PBS viewers like you.

NARRATOR: Peering over the rooftops
of modern Athens

from its throne
atop the ancient Acropolis,

the sacred city in the sky,

the Parthenon rules
in shimmering splendor.

Even in its present form,
a stark marble ruin,

the Parthenon is revered as
an icon of Western civilization.

Its shapely, muscular columns,

crowned with majestic capitals,

are the very symbol
of the classical world.

Its height and width define
perfect proportions.

Its original sculptures
have been looted

and lusted after
for their beauty.

And if imitation is
the sincerest form of flattery,

the Parthenon reigns as the most
copied building in the world--

from the French Parliament,
to the U.S. Supreme Court,

to banks, museums
and countless buildings

that aspire to convey wealth,
culture and power.

BARBARA BARLETTA: The Parthenon remains
an enduring symbol.

It was built to glorify Athens.

But it's taken on
a much greater meaning.

Despite the destructions
of time and man,

it still represents the highest
level of human creativity.

NARRATOR: But as magnificent
as the Parthenon is today,

it is a shadow
of its former self.

2,500 years ago,
the Parthenon was built

as the crowning achievement
of classical Greece.

It towered on the Acropolis

at the center of a complex
of temples and altars,

vividly painted and adorned
with statues

of mortal and immortal greats.

The most prominent sculpture
stood inside,

a 40-foot-high gold and ivory
statue of Athena Parthenos,

the patron goddess of Athens.

(machines chugging and whirring)

But that was then.

Where Athena once stood,
today stands a crane.

Not a trace of her statue
remains.

Now her holy precinct is
a construction site,

for much of her temple lies
in tens of thousands of pieces,

some scattered around
the Acropolis,

some around the world
and some lost forever.

What does remain standing
is in danger of collapse.

Now, a rescue mission,

the Acropolis Restoration
Project, is trying to save it.

(speaking Greek)

The team, guided by the
meticulous investigations

of Manolis Korres, has set
the bar high,

salvaging whatever ancient
marble blocks remain

in order to create
the most faithful restoration.

The cost to date
is easily over $100 million.

We keep as much as possible
of the original material,

and we do not damage
the ancient material.

The theory is that we preserve
all the original pieces

and we add only a few marble

in order to fit them
to the general construction.

NARRATOR: This capital,
once atop a column,

typifies the struggle they face.

It is in six pieces with many
fragments still missing.

First, master marble masons
need to puzzle together

what pieces they can find,

then meticulously re-create
what is missing.

The block itself weighs
ten tons.

It will need to be hoisted
to the top of a column

consisting of 11 drums,

of which many
are also fragmented.

Together, the drums and capital
may have to support

up to 100 tons of surviving
marble beams and sculpture.

But before they can hoist
the capital into place,

the team must solve
a more perplexing problem.

On which of the Parthenon's 46
columns does the capital belong?

For although the Parthenon
may appear to be

one giant building kit
with interchangeable parts,

it's not.

The building, celebrated
as a symbol of beauty

and perfect proportions,
hides an ancient secret.

Cathy Paraschi
and Lena Lambrinou,

architects on the restoration
team, investigate.

LENA LAMBRINOU: You think that all
the blocks are square in this building,

but, in fact, if you check it
with a set square,

you can see that we don't have
a right angle here.

NARRATOR: And when Paraschi
places her book

on one end of the stylobate,
the Parthenon's foundation,

it can't be seen
from the other end.

This is because there
is a curve in the middle

of the lines
in the stylobate

about 6 3/4
centimeters high.

NARRATOR: Korres and his team
have investigated

every angle on the Parthenon.

And although the building
looks straight,

they've discovered there's
barely a straight line on it.

These curves are no accident.

They start with the foundation,
or stylobate.

Each of the 46 columns
has a gently curving profile

and leans inward.

Even the architraves--

marble beams
that span the columns,

as well as the architectural
elements above them, are curved.

This means that each
of the over 70,000 pieces

of the Parthenon is unique,

and fits in only one place.

And the difficulty of fitting
the pieces back together

is compounded
by the Parthenon's history.

Since it was built
in the fifth century B.C.E.,

it has been shot at, exploded,
set on fire,

rocked by earthquakes,

converted to a church,
then a mosque,

and in the 19th century,

looted for its magnificent
sculptures.

To make matters worse,

at the beginning
of the 20th century,

the Parthenon was subjected
to catastrophic restorations.

PARASCHI: More recent damage was done
in the 1900s

by the restoration team
putting in these iron clamps.

They rusted and expanded,

cracking
and destroying the marble.

NARRATOR:
In addition, the early restorers

put column drums and whole
blocks back in the wrong place.

Before the restoration team
could even start,

they had to correct
these mistakes

by taking apart, block by block,
much of the Parthenon.

Paraschi took
on the Herculean task

of working out
the original positions

of 700 scattered blocks

from the long inner walls
of the temple.

Although the blocks seem
the same,

each block is different.

Each one has its own individual
and perceivable information--

the cuttings, the heights...

We're talking about differences
of a tenth of a millimeter here.

NARRATOR: That's about the thickness
of a hair.

(camera shutter clicking)

The team turned to modern
technology to assist them.

Each stone, like everywhere
on the Acropolis,

was ID'd and entered
into the computer system.

As soon as a fragment
of marble is found,

it takes a number, and
it is entered in the database.

So far, we have 5,500
architectural members

of the Parthenon.

NARRATOR: All with detailed descriptions
of height, width,

slope, corrosion,

cracking, stain marks,

even graffiti.

By mapping these variables,
Paraschi and the team hoped

to reconstruct
the two inner walls.

We found about 52 criteria

we could give, maximum,
to one block of the wall.

NARRATOR: But the puzzle proved
too complex.

NARRATOR: In the end,
to put her wall back together,

Paraschi had to draw each stone
onto a card

and, with the help
of detailed measurements,

shuffle them around.

So the final decision was made
by eye.

NARRATOR: It took five years
to identify the position

of around 500 of the pieces.

It's been over 30 years
since the restoration began.

The Parthenon is a 20,000-ton,
70,000-piece,

three-dimensional jigsaw puzzle.

And worse, it's a puzzle that
doesn't include instructions.

No one has found anything
resembling architectural plans.

NARRATOR:
How did the ancient Athenians

build the Parthenon
with such precision

in less than nine years?

And why
with these subtle curves

and few right angles?

How can the modern restorers
faithfully repair

and reassemble these pieces

before air pollution
and even earthquakes

inflict further damage?

To save this masterpiece
of Western civilization

for the future, Korres
and his team of architects,

engineers and marble masons
will have to unlock

the secrets of the past.

(birds chirping)

HURWIT: The Parthenon was
the greatest monument

in the greatest sanctuary

in the greatest city
of classical Greece.

It was the central repository

of the Athenians'
lofty conception of themselves

and the physical,
marble embodiment

of their values, their beliefs,

their myths, their ideologies.

It was as much a temple
to Athens and the Athenians

as it is to their patron
goddess, Athena Parthenos.

NARRATOR: But just 30 years
before it was built, Athens lay in ruins,

a victim of Emperor Xerxes,

leader of Greece's
traditional enemy, Persia.

(thunder cracking)

The Athenians rally the rest
of the Greek city-states,

and with a series
of heroic military victories

drive out the Persian invaders.

With the foreign threat
neutralized

and nearly 200 cities
across the Aegean

paying into a mutual defense
fund, Athens grows wealthy.

It's now 450 B.C.E.,

and a former general emerges
as leader--

Pericles.

He spearheads an ambitious
campaign to rebuild Athens

and ushers in
the Golden Age of Greece--

a unique window of time

that establishes Western ideals
of beauty, science, art,

and a radical new form
of government--

demos meaning people,

and kratos-- power.

"People power" or "democracy."

BARLETTA:
This is the area of Athens

just beyond the Acropolis

where male citizens came
to vote.

We think that
during the fifth century,

the assembly would have
comprised about 30,000,

perhaps up to 40,000
male citizens.

HURWIT: Mid-fifth-century Athens
was a golden age

because of the constellation

of powerful intellects
who gathered there.

NARRATOR: Socrates studies
philosophy here.

Hippocrates, considered
the founder of modern medicine,

according to later traditions,
visited Athens.

Herodotus, father of history,

and Thucydides write
detailed accounts of this time.

BARLETTA:
Theater especially flourished.

This was a time of Sophocles

and Euripides performing
their wonderful plays

to the public in these theaters,

including this particular one--
the theater of Dionysus

on the south slope
of the Acropolis.

NARRATOR: But while all
of Athens flourishes,

the Acropolis still lay in ruins
from the Persian invasion.

Then, in 449 B.C.E.,
Pericles proposes

to rebuild the temples destroyed
by the Persians.

He opens the question to debate.

HURWIT:
Every monument, every element

of the Periclean building
program had to be voted upon

so that these monuments would
in fact be monuments

of the democracy
and not of one man

such as Pericles himself.

NARRATOR: In a powerful statement
of their self-confidence,

the people of Athens vote
to rebuild the Acropolis

and, at its center, a building
to embody their ideals...

the Parthenon.

(birds cawing)

The Parthenon would be the
largest building in the world

constructed entirely of marble,

and in tracing the path
of that marble

lies the first clue
as to how it was built.

Before the Parthenon,

marble had been imported
from quarries

on islands in the Aegean Sea.

On one of those islands, Naxos,

archaeologists discover
a small temple.

PARASCHI: On the beautiful island
of Naxos, we see this temple,

which is one of the early
archaic Greek temples

made of stone.

NARRATOR: The Temple of Demeter
was constructed

about 100 years
before the Parthenon.

It too was built

with few right angles
or straight lines.

PARASCHI:
We can indicate already

the curvature
of the base of the temple.

Also, the widening of
the lower part of the columns.

NARRATOR:
Why are these builders

deliberately constructing
their temples

with curves
and few right angles?

Professor Margaret Livingstone,
a Harvard neurobiologist,

believes the ancient Greeks
might have been aware

of optical illusions.

MARGARET LIVINGSTONE:
The function of the visual system is not

to transmit an image
to the brain.

There's nobody up there
to look at an image.

It's to transmit information
about the world up to the brain.

NARRATOR: Our brain translates
visual information,

like converging lines,

to help us assess distance
and relative size,

but sometimes
something's lost in translation.

Here the converging lines
are telling us

that the line on the right

is taller
than the line on the left.

The result--
an optical illusion.

LIVINGSTONE: This is another
classical illusion.

If you have two straight lines,

if you add converging lines,

these two lines seem
to bow in the middle.

So if the floor of the Parthenon
has converging cues

as to depth and perspective,

you could have an illusory sag

in the floor of the Parthenon.

NARRATOR: Perhaps to compensate
for the illusory sag,

the builders left extra marble
in the middle.

The ancient Greeks realized

that to construct
a building that appears perfect,

they would have to come up with
a design that tricks the eye.

What they invent is a system
of optical refinements.

PARASCHI: Their concern
was the visual perfection

of the building.

NARRATOR: This small stone temple
on Naxos provides evidence

of the Greeks' keen observation
over hundreds of years.

PARASCHI:
Here we can see

the first optical refinements
already experimented

by the people building
the temple.

Here lies literally

the DNA of the Parthenon.

NARRATOR: But even with the wealth
of Periclean Athens,

it was too expensive

to bring so much marble from
the islands to the mainland.

Fortunately, the Athenians
discover a rich source of marble

11 miles from the Acropolis.

The Pentelicon quarry became

one of the largest and deepest
marble quarries in the world

and is the source for
the restoration today.

(machinery humming and clanging)

In minutes, diamond-tipped saws
cut through the same stone

used by the ancients.

Nikos Toganidis,
the architect in charge

of day-to-day operations
on the Parthenon restoration,

is searching
for a flawless 12-ton block.

TOGANIDIS: Today we are going
to check a marble

that George found here
in the quarry.

NARRATOR: The restoration team
has waited months

for just the right block
to make the new architrave,

the marble support beam
above the columns.

It costs over a million dollars

and will have to support
up to 20 tons.

TOGANIDIS:
Let's measure it.

Let's see
if we have the length

of the marble that we need.

NARRATOR: It seems perfect
except for a hidden vein,

which could compromise
its structural integrity.

TOGANIDIS:
If there is the problem,

then the sound
is quite different.

(speaking Greek)

Now it sounds as a bell.

So, we are going to buy.

Jurgo, bravo.

NARRATOR:
At the time of Pericles,

teams of quarrymen extracted
an estimated 100,000 tons

of marble from Pentelicon.

The cost of extracting
and transporting it,

inscribed in part on this stone
placard from 434 B.C.E.,

was over 400 silver talents,
the equivalent

of more than 400 of their
fully equipped warships.

BARLETTA: Expenses for the construction
of the Parthenon

were recorded on stone annually.

The stone was actually set up
on the Acropolis.

This is because Athens had a
democratic system of government,

so they required
that the expenditure

of public moneys be made public.

NARRATOR: The rest of
the construction budget

was spent on carving
that marble.

In that sense, the workplace
today, as in ancient times,

is less a construction site
and more a sculptor's studio.

We have, in some cases,
to form a new drum

from 100 different pieces.

That is a very,
very difficult work.

NARRATOR: Here, the restorers recovered
a part of an original capital,

but were missing the pieces
to fit around it.

They had to carve them by hand

from the newly quarried
Pentelic marble.

They start by making a plaster
cast of a missing piece.

Then they use
this ancient mason's device,

called a pantograph, to record
the three-dimensional shape

of the cast and transfer it,

point by point,
to the new marble.

LAMBRINOU: It's a very
traditional technique.

Even the Romans were using
the same device

to copy their sculptures
in antiquity.

NARRATOR: Once a new piece is completed,
they can join it with an old.

But will their new piece fit?

It doesn't.

It's just millimeters off.

The moderns will borrow
a technique used by the ancients

for fitting together
two new blocks.

They coat the inside surface
with red clay.

LAMBRINOU: In the points
where it doesn't fit,

it leaves white marks.

Where the clay
goes white,

they have to carve
it a little bit more

and test it again

until they have no marks

when they are closing
the two pieces.

NARRATOR: The operation is repeated
dozens of times

until the new marble
exactly matches

the ancient broken surface.

But even when they succeed,
there's still the challenge

of fitting the restored pieces
precisely back into place.

(speaking Greek)

After months
of painstaking work,

drum number 14192
doesn't quite make it.

As you see here, we have
a small ancient fragment.

We built around it
with the new addition.

Now we are going to move it

and take it
down to the workshop.

NARRATOR: Just a few millimeters
of excess new white marble

has to be cut from the base
at ever so slight an angle

to match the precision
of the original blocks.

LAMBRINOU: These differences of one
or two millimeters is just a miracle.

You can't believe that you have
so small differences.

NARRATOR: And here lies
the Parthenon's central mystery.

How did the ancients sculpt it
with such precision and speed?

NARRATOR: Etched into the marble itself,
Manolis Korres finds a clue.

NARRATOR:
Korres made an extensive study

of the relationship
between tool marks

and the kind of tool and force
necessary to produce them.

(imitating buzzing tool)

NARRATOR:
From these marks,

he reconstructed a type
of chisel lost since antiquity.

NARRATOR:
The marks led Korres

to identify a range of tools
that reflects

centuries of expertise
in metallurgy,

enabling the Greeks to produce
sharper and more durable tools

than we have today.

NARRATOR: And from minute differences
in the chisel marks,

Korres can even identify
the distinctive workmanship

of about 200 different
stonemasons.

They were recruited from
throughout the Greek islands,

and would have had many
different systems

of measurement.

Without a common standard,
coordinating this workforce

would have been
a logistical nightmare.

How did they do it?

One answer lies on the island
of Salamis, not far from Athens.

Here, discovered on a church
wall, was a stone carving.

Today,
it is in the Piraeus Museum.

Architect Mark Wilson Jones
believes

the enigmatic Salamis Stone,

depicting an arm, hands
and feet,

may be a conversion table

for the different
measuring systems--

Doric, Ionic and Common.

MARK WILSON JONES:
This is a tracing I've done

that shows the stone,

and you can immediately see
how the main measures work.

We have this foot rule here

that's 327 millimeters,
more or less the Doric foot.

And here you have a foot imprint

that's roughly
307-millimeter-long foot,

which we tend
to call the Common foot.

And there are in fact
other feet.

For example, this dimension here
is one Ionic foot.

So there is a kind
of whole network

of different interrelated
measurements here.

NARRATOR:
The Salamis Stone represents

all the competing
ancient Greek measurements--

the Doric foot, the Ionic foot

and, for the first time,
the Common foot--

virtually the same measurement
we use today.

Wilson Jones finds evidence

of all three measuring systems
in the height of the Parthenon.

WILSON JONES: That distance
is at one and the same time

45 Doric feet.

That's the ruler on the relief.

It's also 48 Common feet,
which is the foot imprint.

And it's 50 Ionic feet,
all at the same time.

And these are quite
exact correspondences.

NARRATOR: So the Salamis Stone
may have provided a simple way

for ancient workers
from different places

to calibrate their rulers

and cross-reference different
units of measurement.

But the Salamis Stone
may also be a clue

to how the ancient Greeks
were using the human body

to create what we now regard
as ideal proportions.

WILSON JONES: What's extraordinary
about this

is that at the same time

as being a practical device,

it's also a kind of model
of theory, architectural theory

that the perfect ideal human
body designed by nature

is a kind of paradigm

for how architects
should design temples.

NARRATOR:
Among the first to record

that Greek temples were based
on the ideal human body

was the Roman architect
Marcus Vitruvius.

He studied the proportions
of temples like the Parthenon

in the first century B.C.E.,
400 years after it was built.

KORRES: Vitruvius's work
gives us the overall frame

which is necessary
to understand the system

of proportions of the Parthenon.

NARRATOR:
According to Vitruvius,

Greek architects believed in
an objective basis of beauty

that mirrors the proportions
of an ideal human body.

They observed, among many
examples,

that the span
from fingertip to fingertip

is a fixed ratio
to total height,

and height is a fixed ratio

to the distance
between the navel and the foot.

2,000 years after the Parthenon,

another artist
was also searching

for an objective basis
of beauty.

WILSON JONES:
This is a very famous image.

It's drawn by Leonardo da Vinci
in the Renaissance,

and it's based
on Vitruvius' description

of the ideal human body.

And it encapsulates this idea
of its theoretical importance.

And what's really interesting
for us is

that when we superimpose
the Salamis relief

on this drawing,

we see that there's
a remarkable correspondence.

There are differences,
but it's the same principle.

You have the same interest
in the anthropomorphic principle

of getting a kind

of sacred, um,
fundamental justification

for these measures.

NARRATOR: Da Vinci's ideal
Renaissance man famously stands

in a circle surrounded
by a square.

Da Vinci named this image
"Vitruvian Man"

after the Roman architect.

The ratio of
the radius of the circle

to a side of the square
is one to one point six.

That ratio is sometimes
attributed

to the Greek mathematician
Pythagoras, who lived 100 years

before the building
of the Parthenon.

In the Victorian Age,

it became known
as the Golden Ratio.

It was a mathematical formula
for beauty.

For centuries,

many scholars believed the
Golden Ratio gave the Parthenon

its tremendous power
and perfect proportions.

Most notably, the ratio of
height to width on its facades

is a golden ratio.

Today, the Golden Ratio's
use in the Parthenon

has been
largely discredited.

But Manolis Korres
and most scholars believe

another ratio does in fact
appear in much of the building.

KORRES: The width is, for instance,
30 meters and 80 centimeters.

The length is 69 meters
and 51 centimeters.

The ratio being four to nine.

NARRATOR: The four-to-nine ratio
is also found

between the width of the columns

and the distance
between their centers,

and the height of the facade
to its width.

HURWIT:
The Parthenon, like a statue,

exemplifies a certain symmetry,

a certain harmony
of part to part

and of part to the whole.

There's no question that
the harmony of the building,

which is clearly one of its most
visible characteristics,

is dependent upon a certain
mathematical system

of proportions.

WILSON JONES:
For the Greeks,

there was nothing better
than a design based

on the coming together
of measures,

of proportions
and harmonies and shapes.

It's rather like
an orchestrated piece of music

in which the harmonies
of the various instruments

are sort of fused together

in a wonderful, glorious,
orchestrated symphony.

NARRATOR: With something like the
Salamis Stone's use of the human body

as units of measure,

and the idealized human form
to define perfect proportions,

the Parthenon literally embodies
the words

of the Greek philosopher
Protagoras,

who lived in Athens
during the construction

of the Parthenon.

"Man is the measure
of all things."

But proportions and principles
do not a perfect Parthenon make.

(mechanical whooshing)

AUTOMATED VOICE:
Next station-- Acropolis.

NARRATOR: Cathy Paraschi
has been commuting to work

on the Acropolis for ten years.

(automated tune playing)

AUTOMATED VOICE:
Acropolis.

NARRATOR:
In all her time

on the Parthenon
restoration team,

she's still amazed
at one particular achievement

of the ancients--

their precision.

PARASCHI: We have a joint
on the step of the Parthenon

which has been so thin,

it's like one twentieth
of a millimeter.

Thinner than a hair.

Further up, you cannot detect
the joint at all.

And finally, probably due
to an earthquake,

a crack starts from one block
and continues to the other.

And the two behave as one.

NARRATOR:
This is the level of precision

that the restorers need
to match today.

Their reconstructed column drum
number 14192

was taken down
because its base didn't fit.

To achieve the required
precision,

they used
metal smoothing plates,

a technique based
on ancient stone plates

found on the Acropolis.

LAMBRINOU:
It's a very traditional way

to level a marble surface.

We are putting sand
in these holes,

and they just move it on the top
of the stone.

They can make
very small differences

between the surfaces.

NARRATOR:
Manolis Korres believes

the ancient stone sanding plates
could grind

to one twentieth
of a millimeter.

But to stack
and precisely align the drums

presents
an additional challenge.

Again, the modern restorers
uncover an ancient technique

when they separate
these two column drums

for the first time
in 2,500 years.

PARASCHI: The ancients
aligned the drums very simply,

but again, ingeniously.

They had this block of wood
that they cut in half.

The lower part was inserted
at the center of the lower drum,

flush and perfectly fitted.

And the upper part is centered
in the upper drum coming down.

So when the upper drum
is placed,

it centers onto this pin.

The surface
was perfectly connected,

and it was so airtight,
that when we opened the drum,

we found this--
and it's 2,500 years old--

intact.

NARRATOR:
The cedar is so well preserved

that restorers could still
smell the wood put there

by Pericles' stonemasons.

Today, the modern restorers use
the same method,

but with titanium.

(high-pitched whirring)

But even though the restoration
team has solved many details

of the ancients'
engineering secrets,

they are still at a loss
to answer the larger question.

How did the Athenians build
the Parthenon,

with all its subtle curves,
without an architectural plan?

WILSON JONES:
There's a simple problem.

To get a plan

of this size
at a reasonably small dimension

that you can grapple with,
something like this,

which would be around
one to 50 or so--

that would be nowhere near
precise enough

to deal with all
the subtle curvature

and the minute adjustments
that are also essential

for this kind of project.

NARRATOR: One of the subtlest
of these curves can be found

on the Parthenon's columns.

If we pull a string,
we can see

that from the middle
of the column and up,

we can see a curve.

A very slight curve.

NARRATOR:
The curve is gentle,

starting a little less
than halfway up

and tapering again near the top.

It's an optical refinement
called entasis.

PARASCHI:
Entasis means tension.

It gives life
to the column visually.

It resembles an athlete
trying to lift the weight,

even the deep breath
of the swelling of its chest.

It is no longer dead stone.

It has life in it.

It has pulse.

HURWIT: These deviations
from the straight,

from the perfectly vertical,
from the perfectly horizontal

are analogous to the curvatures
and the swellings

and the irregularities
of the human body.

And in that sense, the Parthenon
strikes me as being a sculptural

as well as an architectural
achievement.

NARRATOR: The entasis curve
on the side of the column

is so subtle and so slight,

restorers can only draw it
by computer.

For the ancients
to have drawn it at full scale,

they would have had
to set their compass

at an impossible radius
of nearly a mile.

How they constructed
the curved columns

was one of the last
great riddles

left by the ancient Greek
temple builders.

The answer literally came
to light at Didyma,

200 miles from Athens
in what is today Turkey.

Here, a team of German
archaeologists

was exploring the ruin
of the Temple of Apollo.

Built at the time
of Alexander the Great,

150 years after the Parthenon,

it was the biggest Greek temple
ever conceived--

120 columns, each one

more than twice
the height of the Parthenon's.

The German team noted
an optical refinement,

a curvature,
on the base of the temple,

similar to that
of the Parthenon.

They suspected
there might be more.

Traversing the tunnel to the
temple's sacred inner sanctum,

open to the air,

Lothar Haselberger waited
for his eyes to adjust.

HASELBERGER: Coming out of the darkness
of the tunnel

into that white marble hall
is a blinding experience.

What then to my surprise came up

were regularly incised
horizontal lines.

And I found them
interesting enough

to at least keep them in mind
in order to return at a time

when everything was under
better light conditions.

So I was left wondering.

NARRATOR:
At the mercy of the sun,

Haselberger would have to wait
for just the right time of day

for the light to reveal
more of the mysterious lines.

HASELBERGER: There's a golden time
each day when the sunlight

comes just about parallel
to the surface.

NARRATOR:
It was worth the wait.

HASELBERGER: Coming back again
under better light conditions,

it was a kind of revelation
because I realized

this is a full-sized vertical
section of a column,

the very one
at the front of the temple.

NARRATOR: At just the right place
in the temple of the sun god Apollo,

at just the right time of day,

he discovered what might be
the answer to the riddle--

an almost invisible,
scaled-down version

of the subtle entasis curve
of the columns.

This template represents
a squashed column.

Because it is impossible
to draw the curve of the column

in full size, the Greeks scaled
down the height of the column

by a factor of 16.

Now they had a curve
that could be drawn

with a large compass-like
instrument.

But the genius
behind the template

is that the width
was not scaled down,

so each horizontal line
is still the radius

of a full-scale column.

Now all a stonemason need do

is set his compass to any line
of the template

to get the diameter
of any corresponding point

on the column.

This simple scale drawing
was a key reference

for the stonemasons at Didyma

as they carved one column drum
after another.

HURWIT: Greek stonemasons
were so experienced

in creating optical refinements
like entasis

that they may have been given
relatively little guidance.

NARRATOR: The inscribed template
survived at Didyma

because the temple was destroyed
by an earthquake

and remained unfinished.

But at the Parthenon,

such lines
probably disappeared

when the walls were polished
at the time of completion.

HASELBERGER:
The Parthenon was finished,

the marble surfaces smoothed
and polished

and with it went what we assume

were the construction lines
of the temple.

NARRATOR: The modern restorers
believe the ancient builders

must have had some
similar kind of template

to produce the subtle curvature
on not only the columns,

but most of the Parthenon's
marble blocks.

WILSON JONES: The key problems
are these amazing refinements,

the curvature,
the inclination and so on.

But once you've got them
established,

once you know
with these blueprints

exactly where you are going,

then you can proceed down the
length of the building

and across the front
by repetition.

So once they get going, they can
get going at considerable speed.

NARRATOR: With the discovery
of the Didyma plans,

the restorers have new insight
into the last great secret

of how the ancients
built the Parthenon.

But now they face
the ultimate test

as they place the drum they've
so painstakingly reconstructed

back on its column.

With all its curves and angles,
will this new column drum fit?

It does.

Yes, we are very happy.

NARRATOR: The restorers now
need only apply a finish sanding

to the most distinctive feature
of the columns: the fluting.

The crowning achievement

will come with the placement
of this 12-ton capital

on top of the column shaft.

For Korres and the modern
restorers,

this finished marble is more

than just another piece
of the jigsaw puzzle.

They feel they have
successfully entered

the minds
of the ancient builders

and discovered how Pericles
and his architects

were able to design and engineer

the ideals of beauty
and perfection

into this monumental building.

Using the same marble and
similar techniques and tools,

the Acropolis Restoration team

has reconstructed a part
of the Parthenon

perhaps as perfectly
as the original builders.

PARASCHI: In the next ten years,
the worksite will be empty,

and we will be able to admire

the perfect proportions
of the Parthenon again.

NARRATOR: The Parthenon
was completed in 432 B.C.E.

As the ultimate expression
of Athenian ideals,

the temple is adorned
with mythological battles

of victory--
justice over injustice,

civilization
defeating barbarity,

order prevailing over chaos.

And perhaps for the first time
on a Greek temple,

the Athenians, mere mortals,

depict themselves
alongside the gods.

HURWIT:
And so if human beings,

if the Athenians
on the Parthenon frieze are

elevated near the rank of gods,

the gods are represented
in a way that makes them human,

then the difference
between gods and mortals,

between Athenians
and the Olympians,

is not one so much
of kind as of degree.

This is an extremely
humanistic way

of representing themselves.

NARRATOR: But the temple and society
that built it would not last.

Just one year later,
Pericles goes

to the citizens of Athens
for funds

to equip an army against
the threat of Sparta.

To pay for it, he suggests
they could, if necessary,

strip the gold from the great
statue of Athena.

Soon after, Pericles
and a third of the city die

from the plague.

Athens is crushed
by the Spartans,

who turn the Parthenon
into an army barracks.

For the next two millennia,

the Parthenon would be
abused by Romans,

Barbarians, Christians,
Muslims, Turks,

with the final insult coming
in the 18th and 19th centuries,

when Europeans rediscover
classical Greece

and, out of reverence,

plunder much of its
remaining sculptures...

the most famous of which,
the Elgin Marbles,

are in the British Museum
to this day.

When the Acropolis Restoration
Project began

over 30 years ago,

Manolis Korres and his
colleagues could have chosen

to restore the Parthenon
to its original state,

adorned with sculpture
and friezes,

painted in vivid colors.

Instead, they chose to preserve

what has survived
these 2,500 years--

a majestic ruin,

a witness to what
we needlessly destroy,

and the beauty and perfection
that we can create.

Major funding for NOVA
is provided by:

And:

Additional funding
for "Secrets of the Parthenon"

is provided by:

Major funding for NOVA
is also provided

by the Corporation
for Public Broadcasting

and by PBS viewers like you.

I am PBS.