Original subtitles

Tonight, impressive and mysterious,

they are among the wonders of the ancient world.

These are the monuments that define innovation

and technology that were meant to last forever.

But to this day, no one fully understands

how they were built or why.

CAROLINE CORY: Despite how much we've learned

from the writings on the pyramids,

it's not always very complete or specific.

Now, we explore the top theories

surrounding these 4,600-year-old puzzles.

The pyramids really have nothing to do with the afterlife at all.

MICAH HANKS: Are these markers left for aliens

arriving to Earth from space?

CAROLINE: The pyramids could have been built

to provide a roadmap to paradise.

Can we ever decipher the true purpose

of Egypt's astonishing pyramids?

[music]

Saqqara, Egypt, 2650 B.C.

Workers serving under Pharoah Djoser

are nearing completion on one of the ancient world's

largest construction projects, a pyramid.

MICAH: We can't definitively say

which was the very first Egyptian pyramid,

but Djoser's is certainly

one of the first.

It's 205 feet tall

with a base of 358 by 397 feet,

the size of two football fields side by side,

and it's an amazing feat of engineering and technology.

LAURENCE: Many others are built in the same area.

JASON MARTELL: There are probably even more,

but we know of at least 118 Egyptian pyramids

that still exist today

with extensive ruins.

Most of them have been intact

almost perfectly preserved

over the millennia.

LAURENCE: Including the largest ever built,

the Great Pyramid of Giza.

SAMI JARROUSH: The Great Pyramid is equivalent

to the Empire State Building

of its day.

It reaches 480 feet tall,

and for about 4,000 years,

it is the tallest manmade structure on the planet,

until it's finally dethroned

by England's Lincoln Cathedral in the year 1311.

JASON: It's composed of an estimated

2.3 million blocks of stones,

weighing an estimated six million tons.

And some of these stones individually

are 50 to 80 tons each.

The workforce that was needed to lift these stones

must have been massive.

According to ancient Greek and Roman historians,

it is suggested that it was a labor workforce

of around 100,000 enslaved people.

LAURENCE: And it's not just the size that's impressive.

CHRISTOPHER DUNN: The Great Pyramid is probably

one of the most unique

and most precise buildings

that has ever been built.

It is aligned to true north within 1/20th of a degree.

That is remarkable when you consider

the time period when the Great Pyramid was built.

ROBERT CARGILL: The entire base of the Great Pyramid

is nearly a perfect square, with the western side

being only 5.5 inches longer than the eastern side.

This is .01% difference.

This is an amazing amount of accuracy

for a structure this big this long ago.

The Great Pyramid dates back to the year 2570 B.C.

Within a span of 100 years, ancient Egyptians have gone

from the seemingly modest Pyramid of Djoser

to this stunning masterpiece.

MICAH: But soon after, the period of pyramid building

in ancient Egypt just stops right around 2500 B.C.

And we're not sure really why that is.

Eventually, the knowledge

of how these buildings were built is lost.

LAURENCE: Also lost, the reason why they were built.

CAROLINE: Starting thousands of years ago,

people were already trying to find out

the purpose of the pyramids.

You can imagine the first explorers

crawling in by torchlight.

The first thing they would see in these narrow chambers

would be these thousands of lines

of hieroglyphic inscriptions carved into the stone.

SAMI: Can you imagine?

You go in to solve the mystery, and all of a sudden,

you're given a brand-new mystery that you have to work on.

What is all of this?

MICAH: At this point, no one understands

what these hieroglyphics mean.

But there's more than just writing inside.

SAMI: There are these sarcophagus-shaped stones

that are cut right into the central chambers,

and they're also the right size to hold a human body.

Now, the bodies are not there,

and that's because maybe they were stolen

at a certain point in time.

MICAH: We do know that this evidence

has been found by the 5th century B.C.,

because it's at this time

that we get the very first written theory

about the pyramids.

Because in the 5th century B.C., Greek historian Herodotus

describes the sarcophagi, and he writes

that the pyramids are burial chambers.

LAURENCE: Other pyramids provide more clues.

JASON: Herodotus visits Egypt

and speaks with many of the local guides

who have been taking people to the pyramids for years.

And they describe seeing mummified remains,

sarcophagi, wooden coffins--

enough evidence to support the theories of Herodotus,

that these are tombs.

LAURENCE: For centuries, this remains the accepted theory

on why the pyramids were built.

But without understanding what the hieroglyphics say,

this is all somewhat speculative,

because they might describe these buildings

as something totally different.

LAURENCE: Then, a visit to Egypt

by a famous emperor changes that.

JASON: In a way, we have Napoleon Bonaparte to thank

for our current knowledge of the pyramids.

The emperor has a great appreciation

for art and culture.

During his campaign in Egypt, he orders a team of scholars

to take possession of key artifacts

for the glory of France.

SAMI: In 1799, you've got Napoleon's soldiers

that are digging out the foundation of a fort

near the Egyptian town of Rosetta.

And they come across this four-foot-long black stone

that's just embedded right into the wall.

JASON: It's completely smooth on one side

and covered with three different languages--

ancient Greek,

an ancient Egyptian Demotic script,

and hieroglyphics.

But this time, we have two accompanying languages

telling the same story.

LAURENCE: The Greek and Demotic texts are the same.

Translations of a royal decree

from Egyptian King Ptolemy V in 196 B.C.

ROBERT: The message is essentially royal propaganda,

and it's declaring how wonderful and how generous

the newly coronated king was.

But that's not the real importance.

JASON: What is important is that we have the same story

written in three different languages.

All of a sudden, after thousands of years of wondering,

we finally have the ability to translate

Egyptian hieroglyphics.

We can use the ancient Greek inscription

to finally understand what they had to say.

SAMI: It is not an overstatement

to say that this is probably one of the most important

historical finds of all time.

LAURENCE: The Rosetta Stone, as it's called,

becomes the key to unlocking ancient Egypt,

and perhaps the secrets of the pyramids.

ROBERT: Jean-Francois Champollion

is able to crack the code

hidden within the hieroglyphs,

and it took him 20 years to decipher

what the Rosetta Stone actually said.

Champollion published his findings in 1822,

and he had actually created a decoder ring

for Egyptian hieroglyphics.

LAURENCE: According to the hieroglyphic texts,

the pyramids are indeed tombs.

JASON: But we get a lot more insight

into the nature of the tombs.

Finally, for the first time,

we know who the tombs were built for.

As the hieroglyphics describe, these buildings are meant

to be much more than just a burial place.

They're massive monuments built to the power

of the Egyptian kings.

MICAH: The hieroglyphics identify each one

of the pyramids with the pharaoh who commissioned it.

And according to these hieroglyphics,

each pyramid is given a boastful name

like "Enduring are the Places of Nyuserre,"

"Great is Khafre," or "Menkaure is Divine."

These were designed to be big boastful monuments

to each of the pharaoh's power and permanence.

LAURENCE: But could there be more to the pyramids?

CAROLINE: Despite how much we've learned from the writings

on the pyramids, it's not always very complete or specific.

That's the reason why some suspect

we don't really have the full picture.

SAMI: This has been suspected

since long before hieroglyphics were translated.

In fact, during the 10th century A.D.,

the Arab historian al-Masudi theorizes that these pyramids

are more than likely tombs.

However, he also posits that they could contain

a wealth of scientific, mathematical,

and astrological knowledge.

One of the greatest minds

of the late 17th and early 18th century,

Sir Isaac Newton, also believes that the pyramids

had additional secrets hidden within.

MICAH: Newton was really only speculating in his day,

but thanks to modern research and technological advances

we now have available, we're still uncovering

new information about these incredible buildings.

And as it turns out, Newton may have been right.

There's in fact a lot more to the pyramids

than meets the eye.

LAURENCE: When hieroglyphics are first translated in the 1820s,

it unlocks a trove of new information

about the pyramids of Egypt and why they were built.

SAMI: They were long suspected to be tombs for pharaohs,

and the hieroglyphics confirm this.

But as more of these hieroglyphics are translated,

we find out that maybe these pyramids

had another function as well.

JASON: There's a group of hieroglyphics

that line the subterranean chambers

of the pyramids at Saqqara,

and these date to around 2300

or 2400 B.C.

And they've become known as the Pyramid Texts.

SAMI: They're written in vertical lines,

and they cover the walls of almost every single room

of these pyramids.

Most Egyptian hieroglyphics, even the ones

inside the pyramids, they're offering you names,

they're offering you dates.

They're offering you legacies of the pharaohs,

who the rulers were.

They're talking about the afterlife a little bit.

But in terms of why these pyramids were built,

we don't seem to have that information.

LAURENCE: But these particular texts are different.

These hieroglyphics suggest

a potential purpose

for the pyramids, and it starts

with a fundamental ancient Egyptian belief.

Like many other world traditions,

these texts reveal that they believe

in an eternal soul, which the Egyptians

call the ka.

The hieroglyphics suggest that the Egyptians

believe that the pharaoh's ka travels to the starry heavens,

where he'll live in eternity amongst the gods.

CAROLINE: To some, that means the pyramids

could have been built to provide

a roadmap to paradise.

MICAH: In 1994, Belgian engineer Robert Bauval

and British historian Adrian Gilbert

publish their book "The Orion Mystery,"

which becomes an international bestseller.

JASON: The central crux of the book

is what is known as the Orion correlation theory.

The authors propose that the pyramids of Giza

are designed to match a star alignment

in the belt constellation of Orion.

If you look at an overlay of the Giza pyramids,

and line them up with stars in Orion's belt,

they almost line up.

It's uncanny.

LAURENCE: According to Bauval and Gilbert,

this alignment isn't accidental.

It could also help answer a long-running question

about the pyramids' design.

CAROLINE: Inside the Great Pyramid of Giza,

there are four long, narrow shafts

that lead out from the King's and the Queen's Chambers

up towards the sky.

Now, that's a strange design element,

supposedly for ventilation.

JASON: But why would the tomb need ventilation?

If that was the goal, there are much easier ways to achieve it.

These shafts required a much more intricate construction

in engineering techniques.

The Egyptians went to a lot of extra trouble to build them.

SAMI: Bauval, Gilbert, and a few other authors propose the idea

that these aren't ventilation shafts at all,

and instead, that they're windows

that align specifically with the stars in Orion's belt--

Sirius, Alnitak, and Kochab.

According to references in ancient Egyptian texts,

those stars are where the pharaoh's ka

is supposed to join the father of the gods,

known as Sah, in the afterlife.

SAMI: In addition to being the home for the gods

and for the pharaohs that make it to the afterlife,

Orion's appearance in the night sky

serves another very important purpose for Egyptians.

Every year when the stars of Orion would appear in the sky,

the Nile River would overflow,

bringing life-renewing irrigation to the crops.

So, through the hieroglyphics, we actually have

a written record that the Egyptians

believe their pharaoh is traveling to Orion

after his death.

And then, we also have a potential correlation

between a pyramid's design

and the stars in that constellation.

So, it's as if the pyramid was specifically built

to aim to that region in the night sky.

LAURENCE: However, some think it's more

than just souls that travel.

JASON: In 2012, Belgian author Philip Coppens takes the idea

of the Orion correlation theory and expands on it.

He supports the idea that the builders of the pyramids

may have aimed their pyramid shafts

directly at Orion.

But rather than transport the ka of the pharaoh

to the heavens, he suggested

they could have actually been transporting

the physical bodies.

MICAH: I mean, it's a pretty fantastical interpretation.

How do the bodies levitate and stay up there in the sky?

Coppens doesn't explain that, but he does cite

what he claims is evidence that the pharaohs' bodies

were somehow transported.

JASON: As Coppens describes, a great many of the sarcophagi

inside the pyramids are found empty.

This is true, and Egyptologists

generally attribute that to graverobbers.

SAMI: But Coppens cites multiple examples

of completely untouched burial chambers inside pyramids.

No graverobbers have accessed them,

and yet, when modern archaeologists

finally open these chambers,

bodies are nowhere to be found.

CAROLINE: Coppens states that after the pharaohs

are laid to rest, their sarcophagi

and burial chambers are sealed up,

and then the pyramid somehow moves their actual bodies,

and you're left with an empty tomb.

LAURENCE: Coppens also points

to another ancient Egyptian burial practice

as further proof.

MICAH: As we've seen inside many pyramids,

along with the pharaoh's body, the ancient Egyptians

often left thousands of physical objects as well.

ROBERT: Egyptian burial chambers are large

because they need to be able to hold quite a few things.

Inside of these chambers

we have found all of the things

that a pharaoh would need

to be happy in the afterlife.

His pets were often mummified.

His slaves were often killed and mummified along with him,

because he's gonna need servants in the afterlife.

It's not uncommon to find large quantities

of beer and bread so that the pharaoh

can have something to eat and drink

in the afterlife as well.

MICAH: Coppens asks, if the journey to the afterlife

is only a metaphorical trip by one's soul,

then why pack up all this stuff?

You know, why leave it there to be wasted?

Again, to him, this could prove

that the Egyptians intended the voyage to be literal.

JASON: This of course fails to account

for all the many mummies that we have found

inside the pyramids.

SAMI: Is it likely that physical bodies

were actually being shot up to the stars?

Probably not. But what we can see though,

is that these pyramids were designed

with the afterlife in mind,

specifically a journey to the afterlife.

Whether it's the ka or something else entirely,

the Egyptians believed in the pharaoh's ability

to make it to their place in the heavens

with the help of these buildings.

LAURENCE: For thousands of years scholars have debated

why the pyramids were built.

But few questioned how they were built,

assuming vast numbers of slaves were forced to construct them.

MICAH: The ancient Greeks estimated

that the Egyptians had used

a labor force of 100,000 slaves

to build the Great Pyramid.

LAURENCE: Then, in the late 1990s,

a surprising archaeological find

upends that notion.

JASON: Egypt's chief archaeologist Zahi Hawass

is responsible for countless amazing discoveries

in the country.

But starting in 1990,

he embarks on a 20-year-long dig

at the Great Pyramid.

ROBERT: He makes an incredible discovery

that makes us rethink

how the pyramids were constructed.

SAMI: He locates the tombs of the people

who built the Great Pyramid, and he learns two things.

First, they weren't enslaved people.

And secondly,

it wasn't 100,000 people.

It was more around 10,000.

ROBERT: The evidence he finds is that these men were buried

according to Egyptian religious burial customs--

meaning that the men who built the pyramids

were from working-class Egyptian families.

JASON: The tombs are built right next to the king's pyramid.

Now, the workers are buried more modestly,

but they're entombed with beer and bread for the afterlife,

an honor not provided to slaves.

The tombs also have graffiti on their walls

calling them "friends of Khufu," the pharaoh.

According to Hawass, there's no way

that would have happened if these were slaves.

SAMI: Hawass also finds evidence of how well these people lived.

They were given a great quantity of food,

and luxurious food like meat.

So here, we have a labor force that is skilled,

they're well taken care of, they're not enslaved,

and there's only 10,000 of them.

How does this make any sense?

MICAH: How exactly do 2.3 million

gargantuan stone blocks get cut,

moved, and fit together so precisely

that it's literally impossible

to slide even a credit card between 'em,

all by 10,000 people?

JASON: Did the Egyptians use ramps?

That seems implausible, since a ramp

with a low enough slope

would have to be over a mile long.

It would be bigger than the Great Pyramid itself.

Had the Egyptians built canals capable of raising water levels

high enough to allow some of these massive stones

to float to the top?

Again, at the very least, that would take

many more than 10,000 individuals.

LAURENCE: According to author Erich von Daniken,

there's only one possible explanation.

JASON: In his bestselling 1968 book

"Chariots of the Gods?", Erich von Daniken writes

that the Egyptians didn't build the pyramids all on their own.

They might have had help from extraterrestrials.

MICAH: So, if we can't figure out how 100,000 Egyptians

built the pyramids, then we certainly have an issue

with trying to figure out how 10,000 could have done it.

In that regard, maybe von Daniken has a point.

SAMI: He calls it the Ancient Astronaut hypothesis.

It states that extraterrestrials came to Earth in ancient times

and helped human beings build these various

architectural marvels.

CAROLINE: In this case, they taught

advanced engineering techniques to the ancient Egyptians

and instructed them on how

to build the pyramids.

LAURENCE: According to this theory,

the pyramids were built as a navigational tool,

not to help the pharaohs reach heaven,

but to help extraterrestrials reach Earth.

MICAH: With the help of modern photography

from satellites and the International Space Station,

we know that the Pyramids of Giza

are indeed visible from space.

And if you look at the pyramids from that vantage point,

I mean, you can't help but wonder if that's how

they were intended to be seen.

Could they be markers for aliens visiting from outer space?

This could also explain why the pyramids

may be aligned with certain stars.

It's the final stop of a landmark-based

navigational system helping aliens

reach our planet from their home world

somewhere beyond the constellation of Orion.

LAURENCE: These theorists also point to alleged evidence

of alien encounters.

According to von Daniken and many other authors

who followed this hypothesis, at the time of their arrival,

extraterrestrial beings would have been considered gods

by the ancient Egyptians.

This notion actually mirrors what we see

in the ancient hieroglyphic texts.

Many hieroglyphic inscriptions do tell us

that the ancient Egyptians believed that their gods

came from the stars.

The story sounds a lot like what von Daniken

is writing about.

According to Egyptian mythology,

the gods lived among them on Earth

and had a great impact on their daily life.

Then, after a time, the gods left Earth.

SAMI: Where did they go?

The hieroglyphics are pretty clear.

They went back beyond the stars.

LAURENCE: Some also believe this Egyptian encounter

wasn't an isolated incident.

CAROLINE: It may have been one of the first visits from aliens,

but it wouldn't be the last,

because Ancient Astronaut theorists

believe this has happened all over our planet.

SAMI: Now, to date, you have 118 pyramids

that have been found all across Egypt.

But you can double that number for Sudan.

They've been found all across China, the Middle East.

And the Americas contain more pyramids

than all other parts of the world combined.

JASON: There's another great pyramid complex

at Teotihuacan in Mexico.

Just like at Giza, these pyramids

are astronomically aligned to certain stars.

There are three main temples.

You've got the Pyramid of the Sun,

the Pyramid of the Moon, and the Pyramid of Quetzalcoatl.

LAURENCE: Just like at Giza,

these pyramids appear to align with the stars

in Orion's belt.

And here again, just like Giza,

the smallest temple, the Pyramid of Quetzalcoatl

is offset from the others and aligned with Mintaka,

the faintest star in Orion's belt.

They're mapped according to the very same principles,

and display the same astronomical message.

So, it's easy to wonder, were these pyramids

designed by the same beings, the same alien civilization

based somewhere around the constellation Orion?

If these structures were designed by extraterrestrials--

and of course, I'm not saying that they were--

but if so, it's easy to see the parallels.

And you could see how some people

might believe they are connected.

LAURENCE: Most Egyptologists, however, reject this theory.

There's simply no real proof.

It is all speculation.

See, for me, the alien theory

detracts from something that's way more awe-inspiring.

The ability of human beings,

especially at such an early time in our history,

to come together, and to design,

and to build these architectural marvels,

is a wonder.

When it comes to solving the mysteries of the pyramids,

the biggest challenge is the lack

of recorded evidence.

But in 1947, new writings are discovered

that suggest a surprising purpose.

JASON: There are two primary sources of information

about the pyramids.

First, there are the Greeks.

But when you read their histories,

you can see that they're just as mystified as we are.

They're mostly guessing.

MICAH: Then we have the hieroglyphics,

which have taught us a tremendous amount

about the ancient Egyptian cosmology and their myths.

But there's nothing in these inscriptions,

nowhere that says why

they had to build the biggest

and most durable structures anywhere on the planet.

LAURENCE: There is, however, one ancient text

that may provide an explanation.

ROBERT: In the spring of 1947,

an amazing trove of Hebrew scrolls

is discovered on the northwest shore

of the Dead Sea.

A Bedouin shepherd boy is out tending his sheep,

and one of his sheep walks up into a cave.

And he's trying to get his sheep out of the cave,

so he throws a rock.

And instead of a sheep coming out, he hears a crash.

SAMI: The noise scares him, and he runs away.

But later, he comes back with a friend,

and both of them enter the cave.

They find a number

of long clay jars.

But then, they look inside,

and they see this dark object.

They bring the jars out into the light,

and they see that the objects are wrapped

in a layer of fine linen, and they're covered in wax.

And when they start unrolling them,

they find long pieces of parchment covered in writing

that have been sewn together.

LAURENCE: They have just stumbled upon

the Dead Sea Scrolls.

Dating back to the 3rd century B.C.,

they're the oldest surviving biblical texts.

It's an archaeological and religious revelation

beyond compare.

Some would even say it's the most important

archaeological find in history.

JASON: The Dead Sea Scrolls expand our knowledge

of the ancient world in countless ways.

One of those ways has to do with Egypt.

MICAH: Among these scrolls is a very old version

of the Book of Genesis.

This ends up, of course, being the first book

of the Jewish Torah and the Christian Bible.

And in it is the story of Jacob and his son Joseph.

LAURENCE: According to Genesis, Jacob has 12 sons

whose descendants eventually become

the 12 Tribes of Israel.

Jacob favors his most beloved son Joseph,

which causes tremendous friction with his brothers.

In a fit of jealousy, they sell him into slavery.

Where is he taken? To Egypt.

MICAH: There in Egypt, Joseph is able

to turn his luck around by interpreting a dream

for the pharaoh about an approaching famine.

And Joseph warns the pharaoh to start stockpiling grain

as soon as possible.

Some biblical scholars believe that this grain

ends up being stored in the pyramids.

JASON: There are two versions of this theory.

Some theorists believe that the pyramids

were always meant to be used for grain storage.

That was one of the reasons why they were designed.

Others believe that they weren't built for that purpose at all,

but got enlisted to store grain because of the impending famine.

LAURENCE: Religious historians have long proposed

that the pyramids were built by Joseph as grain silos.

MICAH: In the 5th century, Julius Honorius,

a renowned Christian grammar and rhetoric teacher,

creates a geographical manual

to help his students understand the world.

His research is compiled into a book

called the "Cosmographia,"

and it explicitly references the pyramids of Egypt

as the horrea Ioseph, or the granaries of Joseph.

SAMI: In the 6th century, this theory pops up again,

and this time it's found in the work of Gregory of Tours.

He's a historian who also becomes

a saint in the Catholic Church.

CAROLINE: In the first volume of his master work,

"Decem Libri Historiarum,"

Gregory of Tours explains,

quote, "Joseph built granaries

"of wonderful workmanship made of square stones and cement.

"They're constructed in such a way

"that they are very broad at the base

"but narrow at the top,

"so that corn could be poured into them

"through a small aperture.

These granaries are still to be seen to this day."

Gregory of Tours has to be talking about the pyramids.

He's even referencing those enigmatic shafts

that appear at the top of the Great Pyramid.

Now, due to the degree of incline,

it is plausible that these kernels of corn

could have been poured in from above.

JASON: You can see that this theory

is represented visually in Christian artworks as well.

The pyramids are very clearly depicted as grain silos

in a prominent 12th century mosaic

in St. Mark's Basilica in Venice.

MICAH: What's more, the granary idea

does not just exist in European circles.

In fact, we find it both in Islamic and in Byzantine texts.

The "Etymologicum Magnum,"

the Byzantine Empire's largest encyclopedia,

explicitly references the pyramids

as royal granaries constructed by Joseph.

LAURENCE: As further proof of the alleged theory,

some authors cite the fact that grain has been found

inside Egyptian pyramids.

SAMI: Now, to an outside observer,

you can kinda see how this theory makes sense.

Think about it, the pyramids sort of have a shape

similar to, like the salt domes that you'll see

on the side of the highway when you're driving, right?

The idea is that these grains will be poured in from the top,

and as they go in, they'll form

like a mound-like shaped structure,

similar to like sand in an hourglass.

LAURENCE: Modern Egyptologists, however,

find a glaring flaw in this argument.

If the pyramids were hollow inside,

this theory would fit like a glove.

But unfortunately, they're not.

They're mostly solid rock,

so there's very little storage room inside.

LAURENCE: But there is evidence that the pyramids were used

to provide sustenance to the community,

just in a different way.

SAMI: The Nile River couldn't always be relied on

to flood and irrigate crops.

As it says in the Book of Genesis,

it references times of both feast and famine.

ROBERT: In times of famine,

a pharaoh doesn't want his subjects to starve.

But he also wants to keep them busy

because they're not working out in the fields.

So, in exchange for payment in the form of grain,

he puts them to work on government projects.

And one of these projects may have been

building the pyramids.

SAMI: So, the pyramids did provide grain,

but in a different way

than what early Christian theorists thought.

MICAH: The fact that a theory is widely believed

doesn't mean it's actually feasible.

We assume the Egyptians had many better options

for storing their grain than the pyramids,

which included actual grain silos.

LAURENCE: There is no more iconic representation

of the might of ancient Egypt than its famed pyramids.

The pyramids might be the most famous

and remarkable aspect

of the Kingdom of Egypt.

But they were only being built

for a relatively short time.

You have a civilization that's around

for about 2,000 years,

yet they only spent about 300 to 400 years

designing these magnificent structures.

So, among the many mysteries surrounding the pyramids,

one important question is, why did they stop being built?

MICAH: In the late '90s and early 2000s,

an all-new theory emerges

that attempts to explain

what might have happened.

And according to this theory,

the pyramids were built with a very specific purpose in mind.

And once this purpose was fulfilled,

the Egyptians didn't need to make any more.

SAMI: In 1998, engineer Christopher Dunn

publishes a book, and in that book,

he posits that the pyramids really have nothing to do

with the afterlife at all.

They're there to serve the everyday life

of the people of Egypt living throughout the kingdom

by providing electrical power.

LAURENCE: Dunn's theory starts with one significant word.

CHRISTOPHER: When you consider the word "pyramid,"

you've got "pyra," which is fire,

and then "mid," which is the middle.

So, when you bring the two together,

you got "fire in the middle,"

and that is essentially what I'm proposing

for the Great Pyramid,

except that it's not a fire of combustion,

but it's an energetic environment.

JASON: With that in mind,

modern-day engineers like Dunn

start to examine the layout

of the pyramids' internal structures.

SAMI: Inside of the Great Pyramid of Giza,

you have three chambers.

You have a subterranean chamber.

You've got a chamber that's been named

the Queen's Chamber,

and one that's been called the King's Chamber.

Traditional Egyptologists have been long focused

on this building as a tomb.

So, they've taken the conventional view

that the pharaoh's body was placed in the King's Chamber,

and the other two could have been used

if the pharaoh died before the pyramid was finished.

However, no human remains or funerary objects

have ever been found inside of the Great Pyramid of Giza.

But that might be the point.

When you look at these chambers through the eyes of an engineer,

you see that they might be serving a different function.

LAURENCE: American engineer John Cadman

also supports this theory.

Cadman is looking into this problem

at the same time as Dunn in the late 1990s,

and he really seizes upon the idea

that this building has a mechanical function

as some kind of pump.

JASON: Water would flow in via the tunnels

from an ancient lake at a higher elevation.

The water would then flow through a duct

up into the Queen's Chamber,

and then exit through an outflow tunnel

to the Nile River.

The next question is, why a water pump?

LAURENCE: To find out, Cadman makes his own model

of the pyramids' subterranean chambers.

In the year 2000, Cadman uses a 500-pound block of cement

to carve out a smaller replica of the Great Pyramid

to study the fluid dynamics

that were happening inside the chambers.

MICAH: Incredibly, when he runs water through,

the block actually starts shaking

with long, and then short pulses.

Now, if you scaled up this experiment

to the full size of the pyramid,

Cadman believes the system would have created

a heartbeat-like vibration that shook the entire structure.

LAURENCE: Eventually Dunn further expands on this idea.

He outlines that the Great Pyramid

is actually a coupled oscillator

which transforms vibrations into energy,

and that generates power.

Dunn's hypothesis also could account

for findings in the Queen's Chamber

that have never been fully understood.

Those twin shafts diagonally extending upwards

from this chamber were once thought of as airducts.

And others have hypothesized

that they target certain stars in the night sky.

SAMI: Now, early explorers reported that the walls

and the ceilings of the Queen's Chamber

were covered with up to about an inch of salt,

and that there was gypsum coming out of the cracks

in the limestone.

Nobody knew what to make of this at the time.

LAURENCE: According to Dunn, it's evidence that the pyramid

served as a chemical reactor.

My theory on the Queen's Chamber is that chemicals

were delivered to the chamber through shafts.

Those solutions were dilute hydrochloric acid

and a hydrated zinc solution.

Those two chemicals brought together

would boil off hydrogen.

JASON: This hydrogen would cause a chemical reaction

with the chamber's limestone, which would explain the presence

of salt and gypsum.

The hydrogen reaction compounds

the pyramid's vibrations exponentially.

It's now really moving and can generate a lot of power.

SAMI: Dunn believes all of these vibrations

charge up the quartz and granite stones

in the center of the pyramid.

This is why they're putting these stones

that weigh 50 to 80 tons in the center.

They're almost like batteries.

And with that, you have yourself an energy source.

LAURENCE: Just how would the Egyptians use that energy?

CAROLINE: According to a 1996 book

by Austrian writers Peter Krassa and Reinhard Habeck,

the ancient Egyptians may have

actually had electric lights.

SAMI: Their theory is based on a relief sculpture

that was found in the 2,000-year-old

Temple of Hathor in Dendera, Egypt.

It shows what they believe to be a massive light bulb

with a socket, a cable, and a filament.

These so-called light fixtures appear prominently

in several other Egyptian artworks as well.

Krassa and Habeck also cite a 1982 experiment

by Austrian engineer Walter Garn.

He sees the so-called Dendera light

and decides to test if such a device

could have been built using the materials

available to the ancient Egyptians.

He was able to make a working model of the device,

but his used traditional electricity,

not pyramid power.

Did the Egyptians actually have electricity?

According to this theory, they did.

And once they had built enough pyramids

to light and power their civilization,

they could stop.

It's-- it's out there, but hey, it's a theory.

LAURENCE: In the late 1990s, two American engineers

make headlines when they suggest that the Egyptian pyramids

were used to generate power.

But they may not be the first to propose this.

There are reports

of a declassified KGB operation

known as Project ISIS.

It allegedly takes place in the 1960s,

and the purpose was to take a look

at these ancient Egyptian artifacts and knowledge

to see if they would be of use to the Soviet Union militarily.

MICAH: One alleged KGB report from scientists

on the Giza plateau stated

that, "during inspection

"of the wall segment, we noted

"an odd sensation.

"A magnetic repulsive force

"seemed to be emanating from the rock.

We were unable to find any scientific explanation."

CAROLINE: In the 1960s,

you have the Cuban Missile Crisis happening.

And right around the same time,

the KGB scientists are walking around Giza.

LAURENCE: In the late 1980s, as the Cold War rages on,

the Russian Academy of Medical Scientists

funds additional research into the power of the pyramids.

These studies are performed by Ukrainian scientist

and defense contractor Alexander Golod.

According to his research,

the pyramids do indeed have the ability to harness energy.

But he doesn't think it's electrical power

the Egyptians were trying to use.

He thinks it was used for healing.

LAURENCE: As part of his research,

Golod builds a series of pyramids

across the Soviet Union.

MICAH: Golod builds over a dozen pyramids,

each one is bigger than the last.

And inside, he does various tasks

measuring their vibration frequencies,

and their ability to focus and direct energy.

JASON: Golod finds that the shape

and size of the pyramid

dictates its energy field.

He builds his 17th and largest pyramid

25 miles north of Moscow.

It's a whopping 144 feet tall

and weighs about 55 tons.

CAROLINE: Golod conducts a research experiment

in conjunction with the Russian Air Force,

which shows that the pyramid creates an energy field

about a mile high, easily detected

by the censors on the aircraft.

LAURENCE: Golod next sets out to test

the energy field's effect on humans.

MICAH: Golod brings all sorts of test subjects

into his pyramids, but he's not yet sure

why the Egyptians built theirs,

or what the pyramid energy is supposed to do.

CAROLINE: What he finds is that after spending time

at the center of the pyramid, people will actually have

a marked improvement on their health.

So, he publishes report after report

about the pyramid's energy promoting growth,

health, and longevity.

He claims that the subjects' blood tests

prove that standing at the center of the pyramid

would actually boost the immune system.

LAURENCE: Over the years Golod shares his research

with a select few.

Russian athletes are known to visit these pyramids

prior to major competitions

to boost their energy and endurance.

Russian cosmonauts are even reported

to have brought water from Golod's pyramids

up with them to the International Space Station

to maintain their health.

Golod's pyramids still regularly draw visitors

from across the country who are eager to experience

their alleged healing energy.

And Golod is happy to provide access

to pyramid-charged water

or healing pyramid trinkets for a small fee.

LAURENCE: Could the very same health-inducing properties

have also been sought by ancient Egypt's pharaohs?

According to this theory, yes.

CAROLINE: Golod believes that the Egyptian pyramids

were used for much of the same reason

that he's using his pyramids today.

In fact, he thinks they could have been used

while the pharaohs were still alive.

SAMI: This could explain a few things,

like why each pyramid was built

as soon as the pharaoh was crowned.

Perhaps the building was meant to be used during his lifetime,

even before it was finished,

to help grant him health and longevity.

CAROLINE: It also potentially explains

why there are a few other chambers in most pyramids.

Like, why is there a Queen's Chamber

while we don't actually have evidence

that a queen was buried there?

Maybe she was allowed to receive the pyramid's healing

in her own chamber, but during her lifetime.

But in death, all that power is reserved

for the pharaoh himself.

Everything focused on his mummified remains

to protect and preserve him for all eternity.

CAROLINE: Ultimately, that's the one thing

we know for sure the pyramids represent--

permanence, strength.

Whether they're actually sending immune-boosting energy,

or electrical power, whether they're storing grain

or serving as alien landmarks,

none of this can be proven at the moment.

But what we can say confidently

is that the pyramids were built to last the test of time.

And that, they have.

Archaeologists in Egypt

have no shortage of work

ahead of them.

Over 100 active dig sites

are currently being investigated,

with many more to come.

As new evidence is pulled from the desert sands,

new truths may be revealed.

I'm Laurence Fishburne.

Thank you for watching

"History's Greatest Mysteries."