Transcript

What Actually Happened to the Sphinx's Nose? What was the Real Antikythera Mechanism Used for & More

From Today I Found Out · Episode page · Watch on YouTube

· 1 h 41 min · 18,393 words · 131 timestamped sections

This is the full, timestamped transcript of "What Actually Happened to the Sphinx's Nose? What was the Real Antikythera Mechanism Used for & More", an episode of Today I Found Out published January 21, 2026 (1 h 41 min, about 18,393 words). It mentions 18 people, works and ideas, including Kafra, Mark Leonard, Antikythera mechanism, Derek Dola Price, Curtis Wayne Wright.

What this episode is about

The Great Sphinx of Giza, an iconic monument over 4,500 years old, remains shrouded in mystery regarding its origins, purpose, and the fate of its missing nose, which is often attributed to popular misconceptions. While traditionally believed to have been built during Pharaoh Kafra's reign as part of an elaborate temple complex, recent insights suggest its construction was somewhat accidental due to the soft limestone used.

Key takeaways

  • The Sphinx: ancient mischief in stone, whispering riddles with every passing breeze.
  • Is Kafra's face a mirage? Many theories, but solid evidence is as elusive as its lost nose.
  • The Sphinx’s nose: a historical whodunit, with culprits far beyond the usual suspects.
  • Sphinx or yardang? A natural phenomenon turned royal art, sculpted by the winds of time.
  • Astronomy and mythology collide: during equinoxes, Sphinx shadows craft stories of gods and kings.

Who speaks in this episode?

What is discussed, and when

  1. – 10:00: Kafra, Mark Leonard, August Marier, Frederick Leuis Nordon
  2. – 20:00: Antikythera mechanism, Derek Dola Price, Mark Leonard, British Museum
  3. – 30:00: Curtis Wayne Wright, Tony Fre
  4. – 50:00: Abu Simbel, Gamal Abdul Nasser
  5. – 1:00:00: Abu Simbel, Aswan High Dam
  6. – 1:10:00: Libyan desert glass
  7. – 1:30:00: Mark Leonard
  8. – 1:40:33: Mark Leonard

Notable quotes from "What Actually Happened to the Sphinx's Nose? What was the Real Antikythera Mechanism Used for & More"

  • When this tablet was re-exavated in 1925, the cart and its accompanying text flaked off and were lost. The most compelling piece of evidence linking the giant sculpture to…
    about Kafra · at
  • 100% historically accurate is the subject of considerable debate. However, recent archaeological surveys by Mark Lennon uncovered the remains of holes where rods or chisels…
    about Mark Leonard · at
  • Appear again in the west for another 1500 years. All this led re to speculate that the antiyther mechanism was indeed a planetarium or other kind of calculator for predicting…
    about Antikythera mechanism · at
  • These was Michael Wright, a curator at the science museum in London. One of Wright's key insights was that the science museum had in its collection a similar artifact to the…
    about Curtis Wayne Wright · at
  • Tony Fre, a British mathematician and documentary filmmaker. Upon reading the solar prize's 1974 paper, Fre citing Arms Razer found the notion of using epicyclic and…
    about Tony Fre · at
  • Significant sites, 22 of which were identified by UNESCO as being at risk of destruction by the Aswan High Dam.
    about Aswan High Dam · at
  • Rescuing 24 giant stone monuments. Of the 24 sites marked for rescue, the largest and most complex was the Rabby's II temple complex at Abu Simbel.
    about Abu Simbel · at
  • Solidifies into glassy globular or dumbbell-shaped objects known as tectites. However, while Libyan desert glass could only have been formed by some sort of extraterrestrial…
    about Libyan desert glass · at

Who and what is mentioned in this episode?

People

  • Kafra — Person · Referenced historical figure · 1 mention · first at
    Presented as the most commonly accepted candidate for commissioning/building the Great Sphinx and associated Giza complex works.
  • Mark Leonard — Person · Referenced expert · 4 mentions · first at
    Cited as an Egyptologist involved in fossil/stone correlation work used to argue the Sphinx-temple quarrying relationship; also tied to later survey claims about the nose damage.
  • Derek Dola Price — Person · Referenced expert · 1 mention · first at
    Central modern scholar in the Antikythera mechanism segment; led major mid-20th-century analysis and published 'Gears from the Greeks'.
    Obscurity. Things changed in 1951 when the mechanism was rediscovered by professor Derek Dola Price, a British physicist and historian of technology working at Yale University.…
  • Curtis Wayne Wright — Person · Referenced expert · 8 mentions · first at
    Presented as a key later researcher who challenged Price’s gear counts, proposed additional functions, and built a working reconstruction.
  • Tony Fre — Person · Referenced expert · 4 mentions · first at
    Discussed as a skeptic of earlier interpretations who contributed to later breakthroughs about lunar anomaly modeling and eclipse prediction; name appears to be a transcript corruption of Tony Freeth.
  • August Marier — Person · Referenced expert · 1 mention · first at
    Cited as a 19th-century French archaeologist who found a statue of Khafre and features (causeway/temples) used to argue a link between Khafre and the Sphinx complex.
    Century French archaeologist August Marier whose face bears a striking resemblance to the sphinxes. Marier also discovered the remains of a processional causeway connecting the…
  • Gamal Abdul Nasser — Person · Referenced historical figure · 2 mentions · first at
    Appears in the Aswan High Dam/UNESCO Nubian monuments rescue segment as Egypt’s leader whose modernization agenda drove the dam project.
    Irreplaceable history. In 1952, the Egyptian monarchy under King Farooq I was toppled in a military coup led by Lieutenant General Gamal Abdul Nassa.
  • Thomas Young — Person · Referenced expert · 1 mention · first at
    Cited for an 1814 report of a carved slab near the Sphinx with a cartouche interpreted to support the Khafre attribution (though later lost).
    And what does survive is almost entirely religious rather than historic in nature. In 1814, English polymath Thomas Young reported finding a carved stone slab beside the sphinx…
  • Zia Ass — Person · Referenced expert · 1 mention · first at
    Quoted concurring with an interpretation of the Sphinx as Khafre-as-Horus offering to Khufu-as-Ra; name appears to be a transcript corruption of Zahi Hawass.
    Ass, a colleague of Lener and former Egyptian minister of state for antiquities affairs, concurs, adding that the Sphinx represents Kafra as Horus, quote, who is giving…
  • James Allen — Person · Referenced expert · 1 mention · first at
    Quoted to emphasize the lack of definitive Old Kingdom historical records explaining what the Sphinx meant to its builders.
    Brown University in Rhode Island, summing up the situation thusly. The Egyptians didn't write history. So, we have no solid evidence for what its builders thought the Sphinx was.
  • Frederick Leuis Nordon — Person · Referenced historical figure · 1 mention · first at
    Cited for 18th-century sketches depicting the Sphinx already missing its nose, used to refute the Napoleon myth.
    Sphinx's nose was already missing long before Napoleon was even born. In 1755, Danish explorer Frederick Leuis Nordon published a collection of sketches and oil paintings made…
  • Muhammad Sim al — Person · Referenced historical figure (alleged vandal) · 1 mention · first at
    Named (via al-Maqrizi’s account) as a Sufi figure who allegedly broke the Sphinx’s nose in an iconoclastic act; identity likely corresponds to Muhammad Sa'im al-Dahr.
    Next most popular theory comes courtesy of 15th century Egyptian historian Taki Al- Mrezi, who claimed that the nose was destroyed around 1378 by a fanatical Sufi Muslim she named Muhammad Sim al.

Companies & orgs

  • Brooklyn Museum — Company · 1 mention · first at
    These legends are just that, legends with little basis in reality. Indeed, there is overwhelming evidence that the Sphinx's nose was already missing long before Napoleon was…
  • British Museum — Company · 1 mention · first at
    The latter of which was discovered broken off between its paws and now resides in the British Museum in London.

Products & tech

Places & events

Full transcript with timestamps

For more than four and a half millennia, the great Sphinx has gazed out over the shifting sands of the Egyptian desert, standing guard before the great pyramids of Giza. Standing 20 m high and 73 m long, the giant stone statue bearing the body of a lion and the head of a man is amongst the most famous and celebrated relics of the ancient world and indeed one of the most enigmatic. For centuries, tourists and historians alike have gazed upon the Great Sphinx and pondered its many mysteries. Who built this strange monument? Whose face does it bear? What purpose did it serve? And most bafflingly of all, what happened to its nose? Today, the Sphinx's missing nose has become a popular historical punchline referenced in countless works from the Asterex comics to Disney's Aladdin. Yet, like so much about the Sphinx, the true fate of this vanished appendage is shrouded in historical myth. And before you go to the comments

and say, "But Simon, EVERYBODY KNOWS WHO broke it off." Please keep watching because it's likely not who you think. Despite being one of the most famous and well doumented monuments in the world, surprisingly little is known about who built the great sphinx or why. The most commonly accepted theory is that the monument was built during the reign of the pharaoh Kafra, who ruled from 25357 to 2532 B.CE. during ancient Egypt's old kingdom period. Kafra was the son of the pharaoh Kufu, who built the great pyramid of Giza, the largest pyramid on the site and in all of Egypt between 2613 and 2577 B.CE. Wanting to match his father's achievement, Kafra built his own slightly smaller pyramid along with a sprawling temple complex that was laid out before it. The Great Sphinx forms a central part of this complex. Though it is now believed that its construction came about somewhat by accident. The heads and most of the body of the Sphinx

are composed of soft nemolytic limestone too soft for ordinary construction leading Egyptologists to speculate that the sculpture started out as a yardang, a natural rock formation sculpted by windblown sand. According to this theory, the builders of Kafer's pyramid noticed the resemblance between this rock formation and the head of a man and decided to sculpt the great sphinx around it, quarrying down to the bedrock below to create the sculptures body. This theory is supported by the work of Egyptologist Mark Leonard and geologist Tom, who in the 1980s cataloged and cross referenced the fossils in the Sphinx's limestone body and the stones used to build the surrounding temple complex. They found that the fossils matched exactly, confirming that the temple stones had been quarried from the area immediately around the Sphinx. None of this evidence, however, conclusively ties the Sphinx to the reign of Kafra or

proves that the monument bears his face. Unfortunately, very little written material survives from the old kingdom. And what does survive is almost entirely religious rather than historic in nature. In 1814, English polymath Thomas Young reported finding a carved stone slab beside the sphinx bearing a cartou or royal seal with the hieroglyphics caft to which Young added the word ra to complete the pharaoh's name. However, when this tablet was re-exavated in 1925, the cart and its accompanying text flaked off and were lost. The most compelling piece of evidence linking the giant sculpture to Kafra is a life-sized statue of the pharaoh found in the ruins of the nearby valley temple by 19th century French archaeologist August Marier whose face bears a striking resemblance to the sphinxes. Marier also discovered the remains of a processional causeway connecting the valley temple to a morttery temple at the base of Kafra's

pyramids helping to further link the two monuments. However, neither of these discoveries is in any way conclusive, and Egyptologists have variously speculated that the Sphinx may actually have been built by Kafra's father, Kufu, or his halfb brother, Deafra, or even the pharaoh Aman Hartup II some 600 years later. Far more mysterious, however, is the symbolic significance of the great sphinx or even its original name. No records of the mythical creature's Egyptian name survive from the Old Kingdom, while the modern term sphinx comes from a similar creature in Greek mythology which appeared some 2,000 years later. What is known is that during the New Kingdom period between 1570 and 1069 B.C.E. sphinxes were known as harmats or Horus on the horizon. Such sphinxes sometimes bearing that of a ram appear frequently in new kingdom architecture such as in the famous avenue of sphinxes linking the temple

complexes of Carak and Luxaw. As Kafra is known to have closely associated himself with the falcon god Horus. It is possible that the great sphinx was also known as harm during this time. Another theory is that the Sphinx is a reference to the double lion god Achre who guarded the entrance to the underworld and the horizon where the sun rose and set. Egyptologist Mark Lennon has also noticed some intriguing astronomical phenomena associated with this monument such as the fact that during the March and September equinoxes, the sun appears to set into the shoulders of the Sphinx and the south side of Kafra's pyramid behind it. Quote, "At the very same moment, the shadow of the Sphinx and the shadow of the pyramid, both symbols of the king, become merged silhouettes. The sphinx itself, it seems, symbolized the pharaoh presenting offerings to the sun god in the court of the temple. Dr. Zia ass, a colleague of Lener and former

Egyptian minister of state for antiquities affairs, concurs, adding that the Sphinx represents Kafra as Horus, quote, who is giving offerings with his two paws to his father, Kufu, incarnated as the son god Ra, who rises and sets in that temple. But without further hard evidence, these explanations remain pure speculation with James Allen, an Egyptologist at Brown University in Rhode Island, summing up the situation thusly. The Egyptians didn't write history. So, we have no solid evidence for what its builders thought the Sphinx was.

Certainly something divine, presumably the image of a king, but beyond that is anyone's guess. Whatever the case, it is estimated that the great sphinx took a team of 100 people around 3 years to carve. Traces of red, yellow, and blue paint on the face and Veronic Mim's hairdress also suggest that the monument was originally painted in garish comic book-l like colors. However, there is also evidence that the Sphinx was actually abandoned before it could be fully completed. In 1978, excavations by Leonard and Horus uncovered a corner of the Sphinx's ditch that was only partially quarried along with several abandoned stone blocks and the remains of a worker's beer jar and toolkit, indicating that at some point the Sphinx's builders had simply walked off the job. As the old kingdom came to a close around 2181 B.CE. the Gizan Acropolis was abandoned and the shifting desert sands eventually buried much of

the temple complex. There the great sphinx lay forgotten and buried up to its neck for nearly a millennium. Then in 1401 B.C.E. the new kingdom pharaoh that Mosa IV reexavated the Sphinx and erected a large granite slab known as the dream seal between its paws. The text on the slab tells the story of how as a young man that Mosa fell asleep near the sphinx and had a vivid dream. In the dream, the statue complained of its ruinous condition and made the young prince an offer. If the mosa cleared away the sand from the sphinx and restored it to its former glory, the sphinx would help the prince become pharaoh. Whether this incident actually occurred cannot be known, but what is known is that when the mosa ascended to the throne, he introduced a sphinx worshiping cult to his people.

Thereafter, sphinxes became closely associated with royalty and the power of the sun. At the close of the new kingdom, Giza was once again abandoned and the sphinx rearied up to its neck. Though the site was frequently visited throughout the Greco Roman period, it was not until the reign of Roman Emperor Nero between 37 to 68 CE that the Sphinx was again re-exavated. In addition, a monumental staircase was erected leading up to a pavement before the Sphinx is paused. The Giza complex continued to be maintained until the reign of Emperor Septimus Seus in 200 CE after which the site was once again abandoned and engulfed by the sands. While the pyramids and the Sphinx remained popular tourist attractions for the next millennium and a half, it was not until the 19th century that the first serious archaeological excavations were attempted. The first was carried out by Genoies adventurer Captain Giovani

Batista Caviglia in 1817. But this effort was ultimately unsuccessful. The sand sliding back into the hole as fast as Kigula and his 160 workers could shovel it out. French archaeologists Sasm Marier and Emil Bar succeeded in clearing away some of the sand. But it was not until the late 1930s that Egyptian archaeologist Salm Hassan was finally able to fully excavate the site. By this time, however, the Sphinx had long ago lost its most distinctive feature, its nose. Much of popular culture bles the blame for destroying the Sphinx's nose squarely on one man, French Emperor Napoleon Bonapart. In 1798, Napoleon and an army of 50,000 men landed in Egypt in order to depose the ruling Ottoman regime and establish a French protectorate. According to the popular legend, it is during this invasion that the Sphinx's nose was destroyed either deliberately by French gunners as target practice or accidentally by a stray cannonball

during one of Napoleon's battles. American conspiracy theorist and black supremacist Luis Farrakhan has even claimed that it was destroyed on Napoleon's direct orders as its distinctly African features challenged European theories about ancient Egypt being the cradle of the Western civilization to quote white supremacy caused Napoleon to blow the nose off the Sphinx because it reminded him too much of the black man's majesty. However, these legends are just that, legends with little basis in reality. Indeed, there is overwhelming evidence that the Sphinx's nose was already missing long before Napoleon was even born. In 1755, Danish explorer Frederick Leuis Nordon published a collection of sketches and oil paintings made during his 1737 travels through Egypt and Nubia, which clearly depict the Sphinx without its nose. Furthermore, the deliberate vandalism of the Sphinx is completely at odds with Napoleon's second major reason

for invading Egypt. In addition to soldiers and sailors, the emperor also brought along a small army of 167 mathematicians astronomers engineers naturalists architects draftsmen writers, and printers to meticulously document Egypt's natural and man-made wonders. He also founded the famous Egyptian institute whose major 1829 publication description de Egypt all but created the modern field of Egyptology. As for the nose being accidentally broken off, the Napoleonic battle most commonly associated with the Sphinx's vandalism actually took place at Embara, several kilometers away from the Giza Plateau. So, if not Napoleon, then who did break off the Sphinx's nose? The next most popular theory comes courtesy of 15th century Egyptian historian Taki Al- Mrezi, who claimed that the nose was destroyed around 1378 by a fanatical Sufi Muslim she named Muhammad Sim al.

According to Al-Makrizy's account, Aldar observed a group of local peasants making offerings to the Great Sphinx in the hopes of securing a good harvest. Enraged at this blatant display of idolatry, Aldar proceeded to break off the Sphinx's nose. In retaliation, the peasants formed a mob and proceeded to lynch Alar. Whether or not this story is 100% historically accurate is the subject of considerable debate. However, recent archaeological surveys by Mark Lennon uncovered the remains of holes where rods or chisels were hammered into the nose to break it off. Leoner estimates that the removal was performed sometime between the 3rd and the 10th century CE, quite possibly by Islamic iconoclasts, as al-Maces claimed. Other Egyptologists have speculated that the damage may have been inflicted even earlier in antiquity based on ancient Egyptian beliefs regarding the power of statues and body parts. According to

Edward Bleberg of the Brooklyn Museum, quote, "In temples or tombs, the damaged part is the part that had a function during a ritual. If the ritual required the statue to smell, see, hear, or even eat, then the nose, ears, eyes, or mouth to prevent the ritual from working. But until new records are discovered, or the long missing nose is found, we may never know for certain who defaced the Sphinx. But its nose is not the only major component the Sphinx has lost over the centuries. At one point, the statue sported a cobra on its forehead and a ceremonial feronic beard on its chin, the latter of which was discovered broken off between its paws and now resides in the British Museum in London.

Certain early sources also described the Sphinx as sporting a crown, and indeed, the top part of its head bears a large hole that may have been used to anchor this feature. Over the years, the statue has been the subject of a number of indignities, both by treasure hunters seeking to penetrate its interior and well-meaning archaeologists attempting to restore and preserve the monument. At some point in antiquity, a long tunnel was bored into the Sphinx's rump and later covered over. While in 1837, British Egyptologists Howard Vice and John Bearing attempted to drill into the statue just behind the head. The drill rods became stuck at a depth of 8 meters, while attempts to loosen them with explosives resulted in yet more damage, including breaking off a piece of the headdress. And this is why we can't have nice things. In 1931, in an attempt to prevent further damage, Egyptian engineers shored up the

headdress with concrete, creating the now iconic, if historically inaccurate, diamond- shaped profile. Further renovations were undertaken in the 1980s and 1990s to shore up the Sphinx's body, whose soft limestone composition makes it exceptionally susceptible to erosion by windblown sand. While thankfully the Sphinx is now safe from religious iconoclasts and explosives toting treasure hunters, it now faces a whole new set of dangers in the form of pollution and climate change. In 2007, Egyptian authorities discovered that the Giza water table had risen due to sewage being dumped into a nearby canal. This resulted in water percolating up into the Sphinx's porous limestone body, causing large pieces to flake off. In response, the government installed pumps to keep the ground below the monument dry. Yet, despite this, acid rain from industrial pollution still threatens to speed up the Sphinx's erosion, while

climate change may cause the level of the Nile to rise, resulting in further destructive flooding. Unless these threats are effectively dealt with, the Great Sphinx may eventually crumble into dust, returning to the smothering sands it has so stubbornly defied for over 4,000 years. In 2023's Indiana Jones and the Dial of Destiny, the latest entry in the iconic adventure film series, everyone's favorite swashbuckling archaeologist/grave robber hunts down the titular dial, a mechanism invented by ancient Greek mathematician Archimedes to predict the appearance of fishes in time, allowing the user to travel between the present and the past.

Because, I mean, sure, why not? But while this fantastical plot element might sound like the product of a particularly drunken session of antiquities themed mad libs, amazingly it is actually based on a real life artifact called the antiyther mechanism. Dating from the 1st century BC, this incredibly sophisticated assembly of bronze gears has baffled archaeologists for over a century, predating the earliest known mechanisms of its kind by more than a millennium. Only in recent years has its true function been determined. Revealed to be an ancient form of analog computer, the oldest on record. This is the story of the most incredible example of ancient mechanical and mathematical genius ever discovered.

So, let's dive in, shall we? And speaking of diving, in the spring of 1900, a team of Greek sponge divers from the island of Siame were returning home from a fishing expedition off the North African coast when a violent storm struck. Blown off course, they were forced to take shelter in a cove on the small island of Antiqira, northwest of Cree. The following morning, the leader of the expedition, Captain Demetrius Kontos, decided to try his luck in the waters off the island and sent diveratoss down to search for sponges. Minutes later, a visibly shaken. Stardatoss suddenly resurfaced, frantically exclaiming that the seafloor was strewn with dead naked bodies. When his fellow divers investigated, they discovered that the bodies were in fact large bronze and marble statues. the cargo of an ancient shipwreck lying 45 m below the surface. Upon reaching their home port, the crew reported their discovery

to the Greek archaeological service, who in 1901 launched an expedition to Antither. Over the course of 8 months, the team recovered thousands of artifacts, including magnificent statues pottery jewelry and glassware. From these finds, the wreck was determined to be a Roman ship from the 2nd century B.C.E., its cargo of fine and expensive art objects likely destined for a wealthy buyer in Rome. Then on May the 17th, 1902, archaeologist Valerio Sty was cleaning some of the many corroded lumps of metal from the wreck when he discovered something completely unexpected. A fused mass of complex intershing bronze gears and wheels like a large mechanical clock. While the ancient Greeks were known to have used simple peg tothed gears for machines like water wheels and windmills, the precision of these gears was unlike anything yet discovered from the period, sparking furious debate among archaeologists. Many refused to

believe that the ancient Greeks could have created such a sophisticated device, declaring the mechanism to be a forgery or a late device that conveniently sank in the same area as the wreck. Others argued it was the remains of a particularly complex astrolave, a common ancient device for making astronomical measurements and calculations. While still others believed it to be a planetarium or an ory, a mechanical model showing the motion of the planets. Meanwhile, in 1905, a German philologist named Arthur Ree conducted the first in-depth analysis of the mysterious device.

Observing that many of the gears and the remains of the wooden box that held them were covered in Greek writing, Ree attempted to translate as much of the text as possible. What he discovered was part of an ancient almanac known as a parapgma, which predicted various astronomical phenomenon such as equinoxes, solstesses, and the rising and setting of various constellations. He also discovered the names of the five planets known to the ancient Greeks, Mercury Venus Mars Jupiter and Saturn, and that certain key numbers, particularly 1976 and 223, appeared several times throughout the mechanism.

But perhaps Ree's greatest observation was that not all the gears in the mechanism were simply fixed to the wooden base. Instead, some rotated on or within other gears, forming epicyclic gear sets. This was a startling discovery for epicyclic gears would not appear again in the west for another 1500 years. All this led re to speculate that the antiyther mechanism was indeed a planetarium or other kind of calculator for predicting astronomical events. However, unable to penetrate the thick corrosion encasing the mechanism and more closely examine its components.

He made no further progress and the antiyther mechanism soon faded into obscurity. Things changed in 1951 when the mechanism was rediscovered by professor Derek Dola Price, a British physicist and historian of technology working at Yale University. Price immediately became obsessed with this ancient enigma and devoted much of the next 20 years to cracking its many mysteries. He was aided in his quest by two key developments. Though the antiyther mechanism had been recovered in 1901 as one solid corroded lump, over the intervening half century, it had broken into around 20 smaller fragments, revealing more of its inner workings.

Advancements in X-ray technology also made it possible to look inside the larger concretions without damaging them further. Dissol Price therefore teamed up with Greek radiologist Cheryl Lambos Caracalos to take the first detailed 2D X-rays of the mechanism. These not only revealed 10 previously unknown gears, but also hundreds more Greek characters providing vital clues to deciphering the mechanism. For example, on the surviving fragments of the front outer dial, Dolapric discovered the words Pachon, Pani, and Epiphy. the 9th, 10th, and 11th months of the ancient Egyptian lunar calendar. Meanwhile, the inner front dial was divided into 360 degrees as well as 12 segments marked with the signs of the zodiac. The dial also featured 20 individual letters which D solar Price realized corresponded to Arthur's parapgma almanac. From these clues, Dolaprice determined that the front dial of the mechanism tracked the

side rail motion of the sun and the moon. That is their motion relative to the so-called fixed stars. The two pointers that once traveled across the dial, however, had long ago corroded away. Also lost to history was a hand crank on the side of the case, which dissol determined through context must have driven the entire mechanism. Another key feature of the front d was the rotating outer ring, which allowed the operator to account for the effects of leap years and the intercalorie month. The four to five days added to the end of the cenotic year to synchronize it with the tropical year.

Examining the X-rays, Dolan Price and Carac Carlos next set about counting the teeth on each of the gears, which was vital for determining exactly which astronomical cycles the mechanism was intended to model. This proved more challenging than expected, as many of the gears were only partially preserved. And since a difference of just one tooth could entirely throw off the analysis of the mechanism, the analysis ran into many frustrating dead ends. For example, Caracalos believed that one particular gear had 128 teeth while Doliprice believed that it had 127. Doliprice turned out to be correct. For 127 is half of 254, the number of tropical or solar months in the Metonic cycle. First discovered by the ancient Babylonians, but named after fifth century B.C.E.

Greek astronomer Metton of Athens. The meatonic cycle is a period of 19 solar years or 235 cenotic or lunar months after which the phases of the moon occur at the same time of year. The same number 19 that Arthur Ree had discovered repeated throughout the mechanism. The matonic cycle is still used today by many religions to determine the dates of certain holidays including Easter, Roshashana, and Ramadan. This particular 254 to gear drove a pointer on the rear upper base of the mechanism which indicated all the lunar months in a single 235month matonic cycle. Finally building from Arthur Re's insights about epicyclic gear sets to solar price concluded that these mechanisms were used to calculate the phases of the moon. In 1974, he published his 20 years of findings in a landmark paper titled Gears from the Greeks. DolPrice's paper shook the world of archaeology, causing many to rethink their assumptions about

the mathematical and engineering abilities of the ancient Greeks. It also inspired many researchers to tackle the puzzle of the antiyther mechanism. Among these was Michael Wright, a curator at the science museum in London. One of Wright's key insights was that the science museum had in its collection a similar artifact to the antitherther mechanism, a sixth century CE device known as the Byzantine Sundar calendar. When the mechanism is spun, the name of the month appears in one window while a graphical representation of the moon's phases appears in another. While the mechanism is relatively simple, containing only eight gears compared to the antiythera mechanisms 30, the similarities between the two designs suggest that the Byzantine sundial calendar was part of a long engineering tradition stretching back to the antiyther mechanism and even beyond.

This along with the discovery of a new mechanism on the front dial led right to hypothesized that the moon pointer on this dial included a rolling spherical indicator to display the phases of the moon. Incredibly, this mechanism made use of a differential gear train, a technology not previously thought to have been invented until the 16th century. In the early 1900s, Wright along with Australian historian of technology Alan George Brmley performed linear X-ray tomography of the antiyther mechanism, obtaining even more detailed, easier to interpret 3D scans. From these scans, the pair was able to determine that much of DolPrice's analysis of the mechanism was fundamentally flawed, with 17 out of his 20 gear tooth counts proving to be incorrect. Based on his more accurate counts, as well as inscriptions found by Arthur Rain, Wright hypothesized that the front dial also featured pointers now lost

representing the orbits of the five known planets, the motion of which was informed by the theories of ancient Greek astronomers Appalinius of Perg and Hypocus of Roads. The ancient Greeks knew that the planets sped up or slowed down and sometimes even reverse direction as they orbit it. A phenomenon known as retrograde motion caused by the earth overtaking the planets as it orbits around the sun. Indeed, the word planet from the Greek planetes or wanderer is derived from this behavior. However, the ancient Greeks believed in a geocentric model of the solar system wherein the sun, moon, and planets orbited the earth. To account for retrograde motion, Apollonus and Hippus theorized that the planets not only traveled in circular orbits around the Earth, but also in smaller epicycles attached to said orbits. While not an accurate literal representation of the solar system, this model was mathematically accurate enough to

perform practical astronomical calculations and to be mechanically modeled by epicyclic gear sets like in the anti-yther mechanism. The epicyclic gear system would remain the dominant model of the solar system for more than a millennium and a half until it was finally overturned by Capernicus, Galileo, and others in the 16th and 17th centuries. Wright and Brmley's 3D scans led to a number of other key discoveries, such as the fact that the two dials on the rear of the mechanism were not concentric circles, as had previously been assumed, but rather spirals. Furthermore, the pointers on these dials were telescopic and featured a peg that rode in a groove on the spiral dial, allowing them to expand and contract as they traveled around the dials. This clever arrangement allowed much longer and accurate measurement scales to be compressed into a more compact space. Wright and Brmley also discovered a small dah within the lunar

dial which appeared to measure the 76year calipic cycle named after Greek astronomer Calipus. This cycle represents the common multiple of the tropical or solar year and the cenotic or lunar month and is a more accurate improvement on the Babylonian 19-year matonic cycle. It also corresponded with the number 76 which Arthur found repeated throughout the mechanism. Based on all these discoveries in 1997, Wright constructed the first practical working model of the antitherero mechanism. Another researcher who was skeptical of Dolar Price's initial findings was Dr.

Tony Fre, a British mathematician and documentary filmmaker. Upon reading the solar prize's 1974 paper, Fre citing Arms Razer found the notion of using epicyclic and differential gears to determine the phases of the moon too unnecessarily complex to be true. After all, there were much simpler and more efficient mechanical means of obtaining these values which any competent Greek mathematician would have known. In any event, in 200 and a team of British and Greek researchers formed the antiyther mechanism research project and launched a fresh assault on the enigmatic mechanism secrets. This effort involved the use of state-of-the-art digital 3D imaging developed by Huelet Packard and an 8tonon X-ray tomography machine built by UK firm Xtec Systems. Both of which had to be transported to the National Archaeological Museum in Athens since the antiyther mechanism is too fragile to travel. But the team obtained much

more than highresolution photos and X-rays. While working at the museum, they were approached by a curator who had discovered a box labeled antitherra in a storage room. The box turned out to contain 72 extra fragments of the mechanism, increasing the total to 82. The largest seven of these fragments are now designated by the letters A to G, the remaining pieces by the numbers 1 to 75. The team's highresolution scans revealed more than 2,000 new text characters in the mechanism, providing new clues to its function. For example, a second smaller dial inside the rear Luna Dial is divided into four quadrants marked with the names Namir, Na, Ismia, and Olympia, all sides of ancient Greek athletic games. This dial thus likely used the lunar calendar to determine the appropriate opening day of these games which took place every two to four years. But the function of one particular component remained

frustratingly elusive. A large 223 to gear behind the lower rear dial. This is connected to an epicyclic set of four smaller gears of which to solid price had theorized calculated the phases of the moon. However, not only does this not make sense from a complexity standpoint, but Tony Fre discovered all four gears in the set have the same number of teeth. This would make the output the same as the input, rendering the whole mechanism pointless. However, Priest then discovered an observation made by Michael Wright. The one of the epicyclic gears features a pin that engages in a slot in another. Its rotation axis is also mounted at a slightly different angle, meaning that the rotation transferred by one gear to another will periodically slow down or speed up. Upon reading this, Frith had a Eureka moment for this mechanism perfectly modeled the orbit of the moon.

We now know that the moon's orbit is not perfectly circular, but rather elliptical, causing its motion across the sky to periodically speed up and slow down, a phenomenon known as the anomalistic cycle. Not knowing about elliptical orbits, however, ancient Greek astronomers like a Parkus modeled this behavior via epicycles. But while this ancient theory neatly explained the function of the offset epicyclic gears, there was a further wrinkle. The moon's orbit is constantly shifting, tracing a flower petal-like path around the Earth like a giant spyroraph. The time it takes for the moon to return to perigee, its farthest distance from the Earth, is slightly longer than the time it takes to return to the same point in the sky, a difference of just 0.112579655 turns per year. Based on this, Frith found that if the input gear had 27 teeth, the rotation of the output gear was slightly too fast. If, by contrast,

it had 26 teeth, the rotation was slightly too slow. But if the input gear had 26 and a half teeth, the output ratio was exactly 0.112579655, accurate to nine decimal places. Though a gear can't physically have 26 1/2 teeth, Frie quickly realized that 26 1/2 * 2 is 53, the exact number of teeth on the remaining gear in the set. By using precise gear ratios and slightly offset gear axes, the designer of the anti-yther mechanism had succeeded in mechanically modeling the elliptical orbit of the moon to a high degree of precision. A staggering intellectual achievement in any era, let alone the 1st century B.C.E. But there was more to come for Freon realized that the number 223 Arthur Free had found repeated all over the mechanism corresponded to the 223 lunar month saros cycle that governs solar and lunar eclipses. Furthermore, the lower back dial of the mechanism was covered in short letter groups, nearly

all of which featured the letters sigma and ATA. Realizing that these stood for Selen and Helios, the ancient Greek gods of the moon and the sun, Frie determined that the lower dial was in fact a sophisticated eclipse predictor. With this final breakthrough, the Antither mechanism research project was able to build a new working model of the mechanism with all components accounted except for one, a small 63 to gear called R1 whose function remains a mystery to this day. Some believe it to be the last remaining component of Michael Wright's hypothetical planet tracking mechanism. The rest of which either corroded away long ago or remains hidden somewhere beneath the Aian sea are waiting to be discovered. Others, however, doubt the existence of such a mechanism, arguing that Wright's hypothetical reconstruction is overly complicated and lacks the ingenious elegance of the rest of the mechanism.

Time will tell whether the truth will ever be discovered. But the most tantalizing mystery of all still remains. Who actually built this mechanical marvel and when? Unfortunately, hard evidence is rather thin on the ground. Though there are some tantalizing clues, though the 1901 expedition that first excavated the wreck dated it to the 2nd century B.CE. Excavations conducted by explorer Jacqu Kustoau in the 1950s and 70s uncovered coins minted in the Greek city of Pergamon dated to 86 BC, reducing the age of the wreck by a full century. And while nothing resembling the antiythera mechanism has yet been discovered from this period, there is evidence that devices of this type were widely known in the ancient Mediterranean. For example, just a few years after the antiyther ship went down, the Roman statesman and writer Cicero wrote that his colleague, the professor Poidonius of roads recently made a globe which in

its revolutions shows the movements of the sun and stars and planets by day and night just as they appear in the sky. Indeed, the anti-therera ship was built in the Rhodian style, while the parapgma armanac has been shown to be most accurate at latitudes similar to roads. Furthermore, roads was also home to hippocus on whose astronomical theories much of the mechanism is based. Others, however, point to an origin in Pergamon, which minted the coins found aboard the shipwreck, and whose library was second only to the great library of Alexandria in terms of preserved ancient knowledge.

But perhaps the most tantalizing theory credits the mechanism's creation to an even more legendary intellect. Among the many findings of the anti-yther mechanism research project was that the names of certain months on the calendar dial were not universal across the helenistic world, but were instead specific to the citystate of Corinth and its colonies. And one of the major colonies of Corinth was Syracuse on what is now the island of Sicily, home to none other than mathematical and mechanical genius Archimedes. Indeed, in his account of the 221 B.CE siege in which Archimedes was killed by the Romans, Cicero claims that the general in charge, Marcus Marcelus, made off with the sophisticated astronomical instrument designed by the great genius himself. But while compelling enough to inspire the writers of Indiana Jones, unfortunately, this origin story is almost certainly false. For one thing,

Archimedes died more than 100 years before the Antither ship sank. While in 2017 it was determined that though the calendar star used by the mechanism was indeed specific to Corinth, it could not have come from Syracuse. Then again a 2014 study conducted by Christian Carman and James Evans at the University of Puget Sound found that the start date on the Sarah cycle eclipse predictor corresponded to around 205 B.CE only 7 years after Archimedes's death. Meaning that while Archimedes may not have physically built the antiyther mechanism itself, he may have invented many of its operating principles, inspiring a centuries long tradition of mechanical computer construction. Without further evidence, we may never know for certain.

But regardless of who exactly designed it, the antitherm mechanism stands as an astonishing monument to the genius of the ancients, an object the likes of which would not appear again until the 14th century. It also serves as a sobering reminder of just how much ancient knowledge has been tragically lost to history. As Derek Dolric once wrote, "The anti-therero mechanism requires us to completely rethink our attitude toward ancient Greek technology. Men who could build this could have built almost anything they wanted to. The technology was there and it has just not survived like the great marble buildings, statutory and the constantly recopied literary works of high culture.

In the heart of Rome stands one of the eternal city's most famous and wellpreserved ancient monuments, the Pantheon. Constructed during the reign of Emperor Hadrien in the second century CE, the building has been in near continuous use for two millennia. First as a temple dedicated to the Olympian gods and then as a Catholic basilica. Home to exquisitely preserved Roman architecture and the tombs of such luminaries as the artist Raphael and King Victoria Emanuel II. The Pantheon inspired the design of buildings around the world and remains one of Rome's most popular tourist attractions visited by some 6 million people every year. But perhaps it most celebrated feature is its 43 meter coffford dome crowned by a 9m circular oculus or opening that floods the ratunda below with light.

Incredibly, this impressive structure is not built, as one might expect, of marble or brick, but rather of concrete. Even more impressively, it contains not one piece of rebar or other structural reinforcement, making it the largest unreinforced concrete dome in the world. Indeed, the Romans were masters of concrete construction, building all sorts of massive structures from harbors and aqueducts to the famous coliseum from this versatile material. This fact may shock and confuse those of us living in the modern world where one bad winter is often enough to turn concrete roads and bridges into something resembling the surface of the moon. So, what allowed Roman concrete to last millennia, while modern concrete crumbles after just a few years? Well, Roman concrete is known to have reached widespread use around 150 BC, though most archaeologists believe it was first developed nearly a century earlier. Like

its modern counterpart, Roman concrete has two basic components: cement, a powder that sets hard when mixed with water, and aggregate, a mixture of gravel and other small, hard particles that add strength to the mixture. Modern cement known as ordinary Portland cement or OPC is made by heating limestone as well as various other ingredients including clay, iron or sand, gypsum and coal ash in a kiln to produce a lumpy mixture called clinker. The clinker is then ground down to produce cement powder. The composition of Roman concrete was broadly similar consisting largely of calcium oxide or quick lime made by heating limestone in a kil. This was then mixed with pulvis or pzilana, a fine glassy volcanic ash found mainly around the Bay of Naples. Posalana was considered the secret source of Roman concrete. So much so that hundreds of thousands of tons were shipped across the Roman Empire as far as Alexandria,

Egypt for use in construction projects. There were however some significant differences between Roman and modern concrete. For example, while modern concrete uses aggregate mainly composed of sand and p-sized gravel, Roman aggregate or cmenta consisted of larger fist-sized chunks of volcanic stone called tera and pieces of brick and other recycled building materials. Like modern concrete, Roman concrete hardened not by drying but via the hydration and crystallization of the calcium aluminium silicut compounds also known as stratlingite formed from the reaction of quick lime and palana and could thus set in the absence of oxygen even underwater. This allowed the Romans to build concrete harbor peers, breakwaters and other underwater structures without the need to build dry copper dams. The earliest example of such hydraulic cement being used is in the construction of the harbor at Bay near Naples in the

late 2nd century B.C.E. while its largest scale application was the harbor of Queseria Marakeima in modern-day Israel whose concrete peers are still intact to this very day. Despite being exposed to the Mediterranean Sea for two millennia, this remarkable longevity baffled architects and material scientists for decades. For while the long-term survival of surface structures like aqueducts is impressive enough, immersion in seawater is ordinarily lethal to concrete causing it to crumble within decades. Yet, not only have the peers at Caesaria Maritime survived, they've actually gotten stronger over time. Even more bafflingly, in terms of sheer compressive strength, Roman concrete is actually 10 times weaker than modern OPC-based concrete, yet somehow many times more resilient. So, what's going on here? to uncover the secrets of Roman concrete's remarkable resilience. In 2013, a team of researchers led by Paulo Montierro, a

professor of civil and environmental engineering at UC Berkeley analyzed samples of concrete from the peers at Caesaria Maritima. To their surprise, they discovered crystals of a rare calcium silicon hydrate material called toberite. These crystals they deduced were formed via the reaction of the material philipsite in the palana ash with seawater that had percolated into the concrete. Not only is toberite harder than any of the concrete's original constituents, but its formation traps molecules like chlorides and sulfates that ordinarily damage concrete. Meaning amazingly that immersion in seawater actually makes Roman concrete grow stronger and more durable with time. As well as potentially improving the performance of modern concrete, this discovery may have wider applications in industry. As aluminous to borite normally requires high temperatures and large amounts of energy to synthesize. Another key to

Roman concrete's durability lies in one of its most historically baffling features. The presence of brittle white inclusions called lime cls throughout its structure. For decades, archaeologists attributed these inclusions to poor quality raw materials or sloppy mixing practices. However, some experts like Admir Massik, a professor of civil environmental engineering at MIT, were skeptical of this explanation. He states, "The idea that the presence of these lime classs was simply attributed to low quality control always bothered me. If the Romans put so much effort into making an outstanding construction material, following all of the detailed recipes that have been optimized over the course of many centuries, why would they put so little effort into ensuring the production of a well-mixed final product? There has to be more to this story." Indeed, in his 10 books on architecture written in 25 B.CE, the

great Roman architect Petrvius laid out extremely precise recipes for concrete, while Emperor Augustus, who reigned from 27 B.CE to 14 CE, spearheaded major construction and restoration projects in Rome that resulted in the widespread systemization and standardization of concrete manufacture. In 2022, the team led by Massik conducted spectroscopic analyses of concrete samples from the moselium of Roman noble woman Cecilia Matea built between 20 and 10 B.CE. These analyses revealed that the lime clasks are composed of various types of calcium carbonate and oxide which are much more brittle than the surrounding cement matrix. Whenever the concrete shifts, either due to the ground settling or the earthquakes that commonly plague the region, this brittleleness causes cracks to form preferentially within the clasps.

However, rain or ground water percolating through the concrete reacts with the clasps, promoting the growth of calcium carbonate crystals that eventually fill and reinforce the cracks. This reaction effectively makes the concrete self-healing, filling small cracks before they could grow into larger and more dangerous fractures. Now to test this theory, Massik cast and cracked two samples of modern and Roman concrete and ran a stream of water through them. As predicted, within two weeks, the cracks in the Roman concrete had sealed themselves, preventing the water from flowing through. Massik's analysis also revealed that the lime clasps could only have formed at high temperatures, indicating that the Romans mixed their concrete very differently than modern builders. Today, quick lime is mixed with water, producing calcium hydroxide, or slaked lime before being added to the concrete mixture. The

Romans, however, added quick lime directly to the mixture, a technique known as hot mixing. Not only does hot mixing produce the high temperatures needed to form the self-heing lime class, but it also reduces overall curing time, allowing for faster construction. But clever chemistry isn't the whole story here. And the final key to the remarkable longevity of Roman concrete lies in the specific manner that it was cast. According to Vuvius, unlike modern concrete which is mixed wet and poured, Roman concrete was mixed dry with as little water as possible with the resulting puttyike mixture being trled into place. Large pieces of aggregate like volcanic terra and brick or building stone fragments were then laid at top the concrete before another layer of concrete was trled on top. The whole layer was then tamped down using special tools. By tightly compacting the mixture and reducing its water content,

Roman builders minimized the formation of voids within the structure, the main source of weakness in concrete, and promoted the formation of tough straddling crystals. Interestingly, the advantages of this construction method were confirmed by a much more recent construction project, and that's the building of the upper still water dam in eastern Utah in 1987. The concrete used in the dam's construction was composed of 40% OPC and 60% coal ash, closely replicating the lime palana chemistry of Roman concrete. This mixture was mixed with minimal water to form no slump concrete, which was spread in layers and compacted into place using giant vibrating rollers. Later analysis of the dam structure has revealed many of the same self-healing properties exhibited by Roman concrete. These various chemical mixing and layup tricks combined to create what Philip Brun, a research scientist at Dupont Chemical,

calls, quote, "an extraordinarily rich material in terms of scientific possibility, the most durable building material in human history." And I say that as an engineer, not prone to hyperbole." End quote. Indeed, scientists and engineers around the world are actively studying the secrets of this extraordinary ancient building material in order to improve the efficiency and durability of modern concrete and urgent task given our current climate crisis. While concrete is an extraordinarily versatile material with 19 billion tons being used every year worldwide, it has an equally outsized impact on the environment being responsible for up to 8% of global CO2 emissions. Most of these emissions come from the production of clinker, which requires temperatures of 1450 degrees C and consumes large amounts of fossil fuels. The use of motor vehicles to transport, pour, and repair concrete also contributes to this carbon

footprint, a problem made all the worse by the low durability of modern concrete. Roman concrete, by contrast, is made from ingredients fired at much lower temperatures, thus requiring less fuel and lasts much longer, greatly reducing the frequency with which it must be replaced. And while Roman concrete's secret ingredient, puzzelana ash, is relatively rare, studies have shown it can be replaced with readily available coal ash with little reduction in performance. Indeed, Roman style concrete made with fly ash could cost up to 60% less to produce than regular OPCbased concrete, providing a powerful incentive for builders to switch over.

Thus, with any luck, this wonder material from two millennia ago may very well help ensure that our current civilization will last another two millennia. But then again, well, what have the Romans ever done for us? On the banks of the Nile, 230 km southwest of the Egyptian city of Aswan, stands one of the most iconic monuments of the ancient world, the temple complex of Abu Simbel. Carved into a mountainside in 1274 B.C.E. by the pharaoh Ramisees II to commemorate his victory at the battle of Kadesh. The temple's facade is dominated by four colossal standown statues standing 20 m high, each bearing the face of the great pharaoh himself. Like the many other grand monuments built over his 66-year reign, Abu Simbel secured for Rammeses what every pharaoh most desired, immortality. His stony likeness standing guard over the desert, solid and immovable for over 3,000 years. Only actually it hasn't. For as immovable as

Abu Simbel might appear today, the great temple stands some 200 meters from where it was originally built 30 centuries ago. This displacement was not the result of some geological phenomenon, but rather an extraordinary human effort to save Abu Simbel and dozens of other ancient wonders from destruction. This is the story of the greatest archaeological rescue mission ever undertaken. Stretching 6,650 km from Lake Victoria to the Mediterranean Sea, the Nile River has been the lifeblood of Northeast Africa since the dawn of human history. Every summer, the Nile floods, depositing a blanket of fertile silt over the land and allowing agriculture and civilization to flourish along its banks. But for all its gifts, the Nile can also be capricious and treacherous.

Its life-giving summer floods can be unpredictable with high waters destroying crops and low waters leading to drought and famine. These flood waters can also only travel so far, limiting agriculture to a very narrow band on either side of the river. And while the Nile has long been a vital transportation artery, the six shallow cataracts or whitewater rapids along its length make travel difficult with boats often having to make multiple overland portages. For these reasons, the peoples living along the Nile have long dreamed of damning up the great river, allowing the early floods to be controlled and the cataracts to be bypassed and water to be stored and diverted for irrigation. The first recorded attempt to tame the Nile was made in the 11th century CE by the great Arab polymath Iben Al-Hatham, better known in the West Al-Hazen. Commissioned by Al-Hakim Bir Amir Allah, the fatimid califf of Egypt,

Alhazen quickly determined that the scheme was impractical with the technology available at the time. Fearing his report would provoke the califf's wrath, Alhazen did what any of us would do in his situation, and he proceeded to feain madness, leading to him being placed under house arrest from 1011 until Al-Hakim's death in 1021. Thankfully, Ahazen made the most of his imprisonment by writing perhaps his greatest work, the highly influential book of optics. It was not until 1898 that the first practical dam across the Nile was constructed by the British on the site of the first cataract near Aswan. Designed by engineer Sir William Wilcox and completed in 1902, the Aswan low dam was a marvel of engineering and at the time of completion, the largest masonry dam in the world. In addition to locks that allowed shipping to bypass the cataract, the dam also incorporated large slle gates that could be opened to

allow flood water and silt to flow downstream or closed to store irrigation water for the winter months. However, the dam quickly proved incapable of meeting Egypt's agricultural needs and between 1907 and 1912 and again between 1929 and 1933, the structure was raised a further 14 m and an electricity generating plant was added. Unfortunately, an unavoidable consequence of this expansion was to submerge the ancient temple complex on the island of Filet. Though occupied since prehistoric times, the island of Filet was first developed in the 4th century B.C.E. during the reign of Pharaoh Nectton Nebo, the first who built a temple to the goddess Isis on the site. In Egyptian mythology, the nearby island of Big was said to be one of the sites where Osiris, god of the underworld, was buried following his murder and dismemberment by his brother Seth. as you do. The area was thus long considered sacred to Osiris as well as

his wife Isis and his son Horus. Over the next thousand years, several more temples would be built on the island, helping to preserve ancient Egyptian beliefs throughout the region's occupation by the Greeks, Romans, and Byzantines. Indeed, the temple of Isis was one of the last holdouts for this ancient religion before it was wiped out by early Christians who defaced much of the ancient imagery in Filelet's temples as graven images. The construction of the Awan load dam raised the level of the Nile by nearly 15 meters, causing the fili complex to disappear underwater for much of the year. Though various proposals were made to move the temples to the nearby islands of Big Air or Elephantine, the British instead chose to reinforce their foundations to prevent them from washing away. Despite this, constant immersion in the Nile began to take its toll on the ancient structures with the silty, slightly

salty water eroding away the surviving paint on the carved reliefs and slowly flaking the poorest sandstone blocks. And so the situation remained for another 30 years until another major construction project threatened to destroy even more of Egypt's irreplaceable history. In 1952, the Egyptian monarchy under King Farooq I was toppled in a military coup led by Lieutenant General Gamal Abdul Nassa. Four years later, NASA ascended to the presidency of Egypt and implemented a series of sweeping and controversial reforms. Among these was the 1956 nationalization of the Suez Canal, formerly controlled by the British, triggering a British, French, Israeli military intervention. Though the coalition succeeded in recapturing the canal, a United Nations intervention led by the United States forced it to withdraw, leaving the canal firmly under Egyptian control. NASA saw himself as the leader of the nent pan-Arab unity

movement and sought to modernize Egypt socially technologically and economically to serve as an example to other emerging Arab nations. Thus, while ideologically opposed to communism, capitalism and imperialism, NASA took a neutral political stance and sought assistance from both Western and Soviet block nations to modernize Egypt's military and carry out domestic development projects, including the construction of a new, larger dam across the Nile. Despite its expansions in the 1910s and 1920s, the Aswan low dam still proved inadequate with the summer floods nearly overtopping the dam in 1946.

Though Greek Egyptian engineer Adrien Danin had drawn up plans for a higher dam at Aswan in 1952, the British controlled government of King Veroo ignored his proposal and instead pursued plans to dam the river further south in Sudan and Ethiopia. On his assumption of the presidency in 1956, Kamal Nasar declared that for political reasons, the dam had to be built within Egypt's borders and turned to world leaders for financial and technical assistance. At the time, both the US and the UK were desperate to rebuild friendly relations with Egypt, which was coming under increasingly Soviet influence. When NASA asked the United States for weapons to modernize its army, US President Dwight Eisenhower agreed on the condition that they only be used for defensive purposes and they allow American advisers to train the Egyptian army. NASA rejected these conditions and instead turned to Soviet Premier Nikki who agreed to

supply Egypt with arms in exchange for deferring payments on imports of Egyptian grain and cotton. Thus, when Nisar asked for assistance in constructing a new Aswan dam, the US and the UK were quick to pledge $70 million, about 700 million today, towards the project. Much of the remainder was covered by the Soviets, who also designed the dam itself and supplied technicians and heavy machinery. Completed between 1960 and 1970, the Aspen Dam was an undertaking unlike any previously attempted in the region. Described by Premier Kruev as the eighth wonder of the world, one of the largest embankment dams in the world, the massive rock and clay structure stands 111 meters tall and nearly 4 km long. It contains 43 million cubic meters of material, stores 46 cub kilometers of water for crop irrigation and generates 2.1 gawatt of hydroelect electricity.

But these advantages came at a cost. for the dam's construction caused the Nile for some 500 km upstream to flood its banks, creating a 5,250 km reservoir known as Lake Nassa. Even before construction began, engineers predicted that Lake Nassa would destroy hundreds of settlements along the Nile and submerge dozens of ancient temples and other archaeological sites. This looming heritage crisis prompted UNESCO, the United Nations Education, Scientific, and Cultural Organization, to launch the greatest archaeological rescue mission in history. The international campaign to save the monuments of Nubia, stretching from the first cataract in Aswan to the confluence of the white and blue Nile in Kartum, Sudan. Nubia is a region rich in history. The region was ruled by one of the earliest civilizations in Africa, the Kerma Kingdom, until its conquest by the Egyptian pharaoh Mosa the first around 1500 BC. The region continued to

be ruled by Egypt until the 8th century BC when the Nubian kingdom of Kush conquered the whole Nar Valley, its kings serving as the pharaohs of Egypt's 25th dynasty. After being ruled by the Greeks and the Romans, Nubia was invaded by the Ethiopian Christian Kingdom of Axum in the 4th century AD and the Ottoman Empire in the 16th before finally being divided between modern-day Egypt and Sudan in the 19th century. This long and eclectic history has left Nubia littered with historically significant sites, 22 of which were identified by UNESCO as being at risk of destruction by the Aswan High Dam.

Though saving these monuments would be a gargantuan undertaking, the anticipated social benefits of the Asswan High Dam made the project's cancellation unlikely. The campaign was officially launched in March 1960 with 50 countries pledging financial and technical support. But before any salvage work could begin, archaeologists from around the world descended upon Lower Nubia to perform one of the largest archaeological surveys in history. As the waters of Lake Nassa would submerge much of the archaeological context of the region, it was vital to gather as much information as was possible before it was washed away, especially about the Nubian people and their culture. And as the aswin high dam took shape and the archaeologists raced against time, teams of engineers and architects from around the world tackled the daunting task of rescuing 24 giant stone monuments. Of the 24 sites marked for rescue, the

largest and most complex was the Rabby's II temple complex at Abu Simbel. Initially, there was considerable debate regarding the best way to preserve the temples. One early proposal by film producer William McQuitty. Architects Jane Drew and Maxwell Fly and civil engineer Ove Arab called for the construction of a permanent rockfilled dam around the temples with the water inside kept at the same level as the Nile downstream of the high dam. Underwater viewing chambers within the dam wall would allow tourists to view the preserved temples. Another proposal by Italian architect and archaeologist Pierro Gazola called for the temple chambers and facade to be cut away from the mountain and encased in a protective reinforced concrete structure. This whole assembly would then slowly be raised by massive hydraulic jacks with pre-fabricated concrete supports being laid underneath the temple until it had

been lifted a full 60 m. The surrounding hill landscape would then be carefully reconstructed, leaving the whole complex in the same position, but at a higher elevation. Though proponents of building a protective dam argued that raising the temples would expose them to excessive erosion by wind and sand, critics counted that the inevitable seepage of water beneath the dam would eventually erode away the temple's foundations. Furthermore, even the most conservative estimates put the cost of the dam scheme at a whopping $82 million, causing the UNESCO committee to reject it outright.

But while the committee initially favored Pierra Gazola's vertical lift scheme, this too was soon found to be prohibitively expensive at an estimated $62 million. The decision was thus made instead to cut the temples apart into small blocks and reassemble them at a site 200 m back from and 65 m higher than the banks of the Nile. Work began in November 1962 under the supervision of Polish archaeologist Casmir's Mikallowski. The first phase of the project involved erecting a coffa dam around the temples to prevent the rising flood waters from interfering with the operation. Drainage tunnels were dug below the temples to divert any seafage.

Scaffolding was erected to support the ceilings and the facads and colossal statues were covered in earth and steel gratings to protect them from damage by falling stones. Then began the delicate task of cutting the entire temple into 1,036 blocks, each weighing between 7 and 30 metric tons. This work was largely carried out by stonemasons from Italy's famous marble quaries who were able to strategically deviate from blueprints when their instincts indicated the presence of soft or unstable rock. Despite the abrasive silica dust thrown up by their cutting tools, the workers refused to wear goggles or masks in order to better see their work, leading to several being hospitalized with respiratory silicosis.

Once cut and lowered to the ground by crane, the blocks were transported by truck up a customuilt road to the new temple site where they were painstakingly reassembled just like the world's largest jigsaw puzzle. The transfer of the blocks was completed by March 1966, while the final block was lifted into place in September 1967. All that remained was to erect a giant reinforced concrete dome encasing the reconstructed temple inside a new waterproof man-made hill. After six years of painstaking work, the rescue of Abu Simbal was declared complete on September the 22nd, 1968. The final cost, $42 million, half born by the Egyptian government and half by foreign sponsors. Soon after, the temple was reopened to the public with a dedicated airport being built nearby to allow easier access for tourists. While the relocation of Abu Simbel was one of the most famous projects of the international campaign and the face of

its success, it was far from the only rescue operation. Throughout the 60s and 70s, dozens of other temples, tombs, and other monuments were relocated to higher ground, often with foreign assistance. For example, the temple of Amada, the temple of Durr, and the tomb of Peanut were moved to a nearby site known as New Amada with the assistance of France. While the temple of Calabshar, temple of Ger Hussein, and Kyosul of Quetasi were moved to New Calbasha with the assistance of West Germany. In exchange for their assistance, several nations received entire temples or parts thereof as grants in return to display in their own museums. The only major archaeological site in Lower Anubia not to be moved was the settlement of Casar Ibrim 100 km southwest of Aswan. Located on a clifftop overlooking the Nile, the site was turned into an island by the rising waters, but was largely spared from damage. Among the last sites in

Nubia to be rescued was the temple complex at Fai, which now lay between the low and high asin dams. As with Abu Simbel, the UNESCO committee initially considered surrounding the island with a protective dam or raising the entire complex above the waterline, but eventually elected to dismantle the complex and relocated to the nearby and higher island of Agilia. Work began in 1972 with the erection of a temporary coffer dam around the island consisting of two layers of steel plates between which a million cubic meters of sand were poured. This allowed water to be drained from around the flooded temple complex. A detailed survey was then conducted of the surface of Fili Island in order to precisely map its topography. These measurements were used to carve the surface of Ajokia Island to exactly match that of Fai, allowing the temples to be reerected in their original positions. The temples were

dismantled into 40,000 components weighing between 2 and 25 tons each, the transfer of which to Ajulka began in April 1977. The reconstruction of the temples was completed in 1980, bringing the international campaign to save the monuments of Nubia to a triumphant conclusion. The project's success inspired the creation of the world heritage convention in 1972 and the modern UNESCO catalog of world heritage sites on which the sites rescued during the 1960 to 1980 campaign are included collectively as the Nubian monuments from Abu Simbal to Palai. In addition to preserving southern Egypt's cultural heritage for future generations and showcasing the power of international cooperation for cultural enrichment, the campaign also demonstrated that it is possible to strike a balance between preserving the past and addressing the pressing social needs of the future. As Vitino Veranei, director of UNESCO,

explained in 1960, it is not easy to choose between a heritage of the past and the present well-being of a people living in need in the shadow of one of history's most splendid legacies. It is not easy to choose between temples and crops. On November the 26th, 1922, British archaeologist Howard Carter, knelt before the entrance of a tomb in Egypt's Valley of the Kings. As his finances, Lady and Lord Carnean, looked on, Carter got a small opening in the sealed door and inserted a candle into the dark space beyond. Quote, "At first I could see nothing, the hot air escaping from the chamber, causing the candle flame to flicker. But presently, as my eyes grew accustomed to the light, details of the room within emerged slowly from the mist, strange animals, statues, and gold everywhere, the glint of gold. For the moment, an eternity it must have seemed to the other standing by. I was struck dumb with amazement. And when Lord

Caravan, unable to stand the suspense any longer, inquired anxiously, "Can you see anything?" It was all I could do to get out the words. Yes, wonderful things. Carter discovered the tomb of Tuten Carman, a pharaoh of the 18th dynasty of ancient Egypt's new kingdom. Though Tuten Carman was only a minor pharaoh, reigning a mere 9 years before his untimely death at the age of 18, the intactness of his tomb and the splendid treasures found therein, immediately made him a household name and set off a global craze for all things Egyptian.

Many of the elaborate grave goods discovered in Tutankerman's tombs, such as the pharaoh's solid gold burial mask, have since become cultural icons, but often overlooked among the piles of gold and jewels are a pair of objects that may very well be the most extraordinary of them all, for they come not from the earth, but from the sky. This is a story of King Tut's extraterrestrial treasures. As with all pharaohs, Tutankaman was buried with everything he would need for his journey into the afterlife, including food, furniture, chariots, board games, and even weapons, including two daggers tucked into the wrappings of his mummy. The first, found along the pharaoh's right thigh, has a solid gold blade, a handle decorated with intricate geometric patterns executed in colored glass paste, and a gold sheath embossed with feather designs, and a hunting scene. The second dagger found just above the pharaoh's

waist is of a similar design only instead of gold the blade is made out of iron. And this is highly unusual for at the time of Tutankerman's death around 1325 B.CE iron was extremely rare in Egypt with large-scale iron smelting not appearing until the 6th century B.CE. This made the metal more valuable than gold. For decades, archaeologists assumed that the dagger, or at least the iron used in its manufacturer, was a gift presented to the pharaoh by a foreign kingdom such as the Hittites. However, in 2016, a team of researchers led by Daniela Kaly from the Polytechnic University of Milan conducted an analysis of the blade using X-ray fluorescent spectrometry, which suggests that the weapon may have had an altogether different, even unearly origin. The analysis revealed that the blade is composed of 88.4% 4% iron, 11% nickel, and 6% cobalt. This is even more unusual than the existence of the blade

itself, for the nickel content of iron smelted before the 19th century has never exceeded 4%. However, there was one source of iron available to the ancients, whose composition closely matched that of Tutankerman's dagger. Meteorites. Meteorites, pieces of space debris which re-enter the atmosphere and reach the ground intact, are classified into two main types. Stony meteorites and iron meteorites. As the name suggests, iron meteorites are composed mainly of iron, though many have a significant nickel content ranging anywhere from 5 to 35%. According to the 2016 study, the composition of Tutankerman's iron dagger places it in the median of a group of 76 previously discovered iron meteorites and almost exactly matches that of a meteorite found in Egypt's cargo oasis. This strongly suggests that the iron used to make the dagger came not from the earth, but from the sky. This discovery is

consistent with many other ancient iron objects found in Egypt, including a set of tubular iron beads found at Gersza, a pre-dynastic burial site 70 km south of Cairo, dating to approximately 3,600 B.CE. Analysis of the beads using electron microscopy and CT scans revealed features consistent with iron meteorites, including a 30% nickel content and intersecting bands of the alloys tanite and camicide called widman start patterns, albeit highly distorted from the metal being cold worked into shape. 19 smaller iron objects were also found in Tuton Carman's tomb, including a miniature headrest and amulets in the shape of ceremonial blades. And these are suspected to also be made of meteoric iron. However, no detailed chemical analysis has yet been performed. If Milan polytechnic analysis is correct and Tutankerman's iron dagger was indeed crafted from a meteorite, this adds a significant spiritual

dimension to the object. As the ancient Egyptians placed great religious importance upon the sky, objects falling from the heavens would likely have been revered as gifts from the gods themselves and worthy only of a pharaoh. Indeed, for much of ancient Egyptian history, the word for iron literally translated as metal from the heavens. But while the origins of Tutankerman's iron dagger were relatively straightforward enough to establish, the providence of another mysterious treasure took considerably more detective work. Discovered in a chest in his tomb's treasury chamber was an elaborate pectoral, a type of necklace popular in Tut and Carmon's time. Made of gold, silver, and semi-precious stones, the pectoral incorporates a number of common mythological motives, including a winged scarab, a boat, uras cobras, lotus flowers, a lunar disc, and the wedge at or eye of Horus. The scarab was often used to represent the sun god

Ra, as the Beatles habit of rolling balls of dung reminded the ancient Egyptians of Ra, rolling the sun across the sky. The body of the ptorial scarab is made of a translucent yellow green material which Howard Carter initially identified as Charlesoni, a variety of the mineral quartz. However, more recent analysis has revealed that the gem lacks the crystalline structure of quartz and is in fact amorphous. In other words, it's made of glass. This is highly puzzling for as with iron smelting, glass making did not appear in Egypt until long after Tuten Carman's death, no earlier than 500 B.CE. So, how did the pharaoh come to possess such an unusual object? A vital clue to the mystery of the glass scarab appeared in 1932 when British geographer Patrick Clayton was exploring the great sand sea of the Gil Kabir Plateau near the border of Egypt and Libya. Scattered throughout the sand, he found numerous small pieces

of translucent greenish yellow material. In 1998, Italian minologist Vincenzo De Miki compared this material to the scarab into Tutankerman's pectoral and confirmed that they were both made of the same material. Clayton had originally assumed that the stones were the quartzrich remains of an ancient dried up lake bed, but later analysis revealed that they were in fact made of glass and thus could only have been formed at high temperatures. Though often thought of as a man-made material, glass occurs abundantly in the natural world with one of the best known varieties being obsidian or volcanic glass which forms when lava cools rapidly. There are also filgarides formed when lightning bolts fuse sand into glass. However, Libyan desert glass as the yellow green chunks are known has a composition entirely different from obsidian and fulgarides with traces of metal such as iron and chromium.

Furthermore, there are no known volcanoes extinct or otherwise anywhere near Gil Kabir Plateau. Thankfully, there is another natural phenomenon violent enough to melt desert sand into glass. And you guessed it, it's a meteorite impact. When a large meteorite impacts the ground at a high velocity, it generates a tremendous amount of thermal energy that melts and scatters rock and sand within the impact zone. This molten rock then cools and solidifies into glassy globular or dumbbell-shaped objects known as tectites. However, while Libyan desert glass could only have been formed by some sort of extraterrestrial impact, nobody has ever found any trace of an impact crater anywhere in the area. Nor are the glass pieces consistent in composition or shape to known tectites.

Bizarrely, the mineral the desert glass most closely resembles, was formed not by natural processes, but by the most violent of mankind's creations. In the early morning hours of July 16th, 1945, night turned to day as the world's first atomic bomb, cenamed Trinity, was detonated near Elmagordo, New Mexico. When the scientists who built the bomb later inspected ground zero, they found not a crater, but a large sheet of greenish yellow glass. This glass, dubbed tritonite, was formed when sand from the desert floor was sucked up into the fireball, liquefied, and then rained back down to Earth. In 2013, eerie similarity between tritonite and Libyan desert glass led professor of geoysics Jan Kramers at the University of Johannesburg to theorize that the latter was formed by a similar but completely natural phenomena, a comet exploding in the atmosphere. Such an air burst, Kramers argued, would not only have

generated the 2,000° C temperatures necessary to melt desert sand into glass, but would also not have left any visible crater. Furthermore, certain trace elements found in the Libyan desert glass, particularly iridium, are more commonly found in comets and meteorites than in terrestrial minerals. This theory is consistent with another suspected comet air burst, the 1908 Tunguska explosion in Siberia, whose effects, such as leaving trees around ground zero standing upright, were similar to those of an atomic bomb. However, a 2019 study by Dr. Aaron Kavosce of the Curtain School of Earth and Planetary Sciences in Perth, Australia, calls Kramer's theories into question. When Kavosi and his colleagues analyzed crystals of what they believed to be zirkon trapped in the desert glass, they discovered that it was in fact a different mineral called reite.

Reedite only forms at extremely high pressures and temperatures far higher than those generated by a comet air burst. Indeed, while an air burst can generate pressures in the millions of pascals, a meteorite impact can generate pressures in the billions, indicating that the latter was in fact responsible for forming the desert glass. However, as mentioned before, no trace of the corresponding impact crater has yet been discovered on the Gil Kabir plateau, though radiometric dating of minerals trapped in the glass indicates that the impact occurred around 26 to 28 million years ago during the mid oligosine epoch. Thus, among the piles of gold, silver, jewels, and other marvelous treasures stuffed into Tutankerman's tomb, it is these two often overlooked objects, an iron dagger, and a greenish glass scarab, which are most befitting of the pharaoh, worshiped as he was as a living god on earth. And when

Titankamoon died and was buried, their celestial treasures would have returned from whence they came. For as the pyramid text of Pharaoh Pepe II tells us, he flies who flies. This king flies away from you, ye mortals. He is not of the earth. He is of the sky. A quick tour on popular online video sharing platforms may convince you that ancient Egyptian builders were either completely useless and had to rely on alien help or they were incredibly advanced and use power tools and lasers because Atlantis, Tom Cruz, and Ice Road Truckers. These hypothesis are a fairly recent trend, seemingly born out of a modern mindset of people who both don't know what they're talking about and cannot comprehend how stuff could be built without the aid of sophisticated technology that they tend to also not really understand and seemingly suffering from a false sense of superiority over our past human selves.

Which, to be fair, that one is an almost universal idea despite it being objectively untrue. Our millennia past ancestors were just as smart as we are. and in some ways far more capable of getting things done with a whole lot less. But going back to making the pyramids, if we look at the writings from people who live closer in time when the pyramids were actually built, we find no such sense of mystery. To them, building huge monuments was impressive, sure, but did not spark wild speculation. Take Greek historian Herodotus for example, writing in the fifth century BC, according to his Egyptian guides, the Great Pyramid at Giza was built by 100,000 men employed for 3 months a year over a period of 20 years. His colleague Diodoris Cichlas, active in the 1st century BC, recounted that the construction was undertaken with the help of ramps of Earth since at that time cranes had not yet been

invented. As we'll see later, further studies by Egyptologists have partially corrected the accounts of these titans of ancient history. Nonetheless, they seem to have gotten the basics right. Building a pyramid was a huge, daunting endeavor, sure, but one that could be achieved by employing resources which the pharaohs had access to. Not too dissimilar to modern-day marvels, like humanity going from horsedrawn carriages to walking on the moon in only a little over a half century. An immutable fact of humaning. When humans throw practically unlimited funds and large amounts of labor and expertise at a problem, we are extremely good at doing the formerly impossible. And countless examples throughout history prove this fact, which kind of makes it a shame we don't do just that at more problems we humans have today. From tuberculosis to cancer to a sequel to one of the greatest sci-fi films of all time in

Galaxy Quest. Let's make it happen no matter the monetary cost. The most important things humans could ever create, Galaxy Quest 2: The Search for Grabthar's Hammer. But in a similar vein, the pharaoh's formula for building the pyramids was loads of time, plenty of cash, building techniques which were state-of-the-art at the time, and tens of thousands of skilled laborers. Yes, skilled laborers, not slaves. Time, money, and skilled labor were the founding blocks for other ancient construction projects which Diodoris and Heroditus might have experienced directly, such as great temples, amphitheaters roads aqueducts and public baths. Many of which, by the way, were architectural and engineering projects, arguably significantly more sophisticated than the pyramids. And yet, no one calls down aliens from the sky as being behind those projects, or at least not yet. Never underestimate what the History Channel is capable of.

Now, those who doubt the prowess of ancient builders still sometimes note how it could be that something as magnificent as the Great Pyramid of Giza might have sprung apparently from nowhere. How and why did the Egyptians come to the concept of a huge pyramid monument? And how could they get it so right right off the bat considering the project started more than 4500 years ago? Well, the truth is they didn't come out of nowhere and proto pyramids abounded. It turns out our friends living along the Nile had been tinkering with other simpler building designs for centuries before honing their craft into those magnificent structures. To begin with, until the 28th century BC, Egyptian kings were usually buried in mastas, rectangular or bent-shaped mounds built of mud bricks or stones.

They had slope sides and a flat roof. Most were about 10 m high and could have a surface area of up to 1,500 m. Their archaeological value today is immense, of course, but compared to what was to come, they were rather unimpressive from an architectural standpoint. And then came Imateep, Chancellor and lead architect to Jozer, first king of the third dynasty, who ruled from 2,667 to 2,648 BC. With Imateep also a man who really didn't like Brendan Frasier for some reason. Clearly, a run-of-the-mill masta would not do for Joseph'serary monument. Thus, Immitep conceived his step pyramid by stacking six mastas, each smaller than the one below, to reach a height of 62 m. This method ensured that Joser's tomb could be easily seen from beyond the high walls of the Sakura complex near Memphis on the west bank of the Nile. It was indeed a burial site fit for a king, and Emoteep would be revered as the first

pyramid builder for a millennia to come. But the design could and would still be improved. The next iteration came courtesy of King Nefaru, founder of the fourth dynasty around 2600 BC. He had an eight-step pyramid built in Maidum, which was later covered in limestone casing, intended to smooth its sides and give it appearance of a true non-stepped pyramid. This building gradually eroded and collapsed over time so that only its core survived. Perhaps Nefru's builders hadn't quite nailed the casing technique yet. The king had two more goes at erecting a pointy-shapederary buildings, both in nearby D'Acher. The first attempt is known as the bent pyramid. As the name suggests, something did not go as straight as planned. From the ground up, the sides have an inclination of over 51°, but about halfway, they rise much less steeply at about 43°. Snaru, however, taught us a great life lesson.

Remember, kids, failures are just learning opportunities. Every single human who ever was was bad at everything at one point except crying and sucking on their mama's boobs. From there, we fail and fail and fail at everything until we don't. In short, if you're ever going to be good at something, you first have to be willing to be bad. From there, as long as you have grit, determination, a clear vision, mountains of cash, and thousands of laborers willing to toil for your eternal glory under the African sun, well, my friends, nothing can stop you. Thus, the so-called Red Pyramid sprung up. or rather it was painstakingly built layer by layer over a period of 10 years. This is a classic example of a true Egyptian pyramid. It is not stepped, it is not bent, and it is massive. Standing in 105 m or 344 ft high. This progress shows how the path to figuring out how to erect one of these monuments was not an

easy one, and several iterations were needed before the Egyptian civilization could deliver one of the seven wonders of the ancient world, the Great Pyramid of Giza. No aliens acquired, just improving techniques over time until they figured it out. This marvel, the largest of all pyramids, was initiated around 2580 BC by King Kufu, son of Nefaru. Its base covers an area of 5.2 hectars, that's 13 acres or almost 10 American football fields. Its sides rise at an angle of 51°, reaching a height of 137 m or 450 ft. Kufu's monument is part of a complex which includes two additional main pyramids built by his successors Kafrey and Manara. Six small pyramids dedicated to their wives, sisters, and daughters, as well as the famous Sphinx. For the sake of this overview, we'll focus on the techniques used to erect the three larger pyramids, all of which were completed in the 26th century BC during the fourth dynasty. To

begin with, the purpose of these and other pyramids was to serve aserary monuments for the absolute rulers of ancient Egypt. They had to stand out to be seen and to be solid enough to resist the tear and wear of centuries until their occupants returned from the dead. And the pyramidal shape fulfills this brief splendidly. Or more precisely, given the building techniques used more than 4,000 years ago, it was the shape that could best deliver on the requirements of the height and solidity. The builders of the Giza complex may have even taken into account the risk of earthquakes. According to Seyed Hamida at the Conservation Department, Faculty of Archaeology, Cairo University, and Algri Sambol at the Egyptian Ministry of Tourism and Antiquities, in their January 2020 paper, Sustainability Problems of the Giza Pyramids, they noted that the maximum static stress under the greater pyramids is about

3,500 kilopascals. Yet, this huge stress value did not entail any observed or likely foundation failure. According to the authors, this shows that the builders had taken into consideration the likelihood of seismic loading. Founding of the monuments for the most part on solid rock and good quality of construction of the foundation favors their good anti-seismic behavior. It is likely that anti-seismic measures had been part of the planning process. Of course, with regards to this and many other things, the truth is there are no surviving plans for Kufu's pyramid, nor documentation of how ancient architects laid down their projects. Well, with one exception, but we'll get to that in a bit. But for now, the mastermind behind the Great Pyramids was Heimunu, who was also halfbrother to Kufu. Kufu's pyramid featured elements previously observed in older monuments such as ascending and descending passageways, niches carved

into walls, and corbelled ceilings. To clarify, these are ceilings in which stone slabs progressively overlap each other as you go higher with a capstone on top to finish off the job. But Heunu experimented with some new features and solutions worthy of such an ambitious project. For Kufu's burial chamber, the architect introduced a flat ceiling made with granite slabs. Now, a flat ceiling may not sound like an impressive feat until you consider that said ceiling had to withstand the weight of countless tons worth of huge rocks. Here in lies the genius of the architect. He stacked five additional layers of granite beams above the ceiling, each separated by a relieving chamber or void spaces, which contributed to distributing pressure away from the king's chamber and the adjacent grand gallery. Another innovation was the junction of the descending and ascending passageways.

The former leads from the pyramid's entrance to the subterranean chamber while the ladder climbs toward the Grand Gallery and Kufu's chamber. Clearly, Hamunu was not entirely sure of how to pull this off and thus first built a scale model in the form of two tunnels dug just east of the Great Pyramid. The model was ultimately unearthed by British Egyptology legend Flender's Petri and is the only surviving evidence of Hemunu's planning work. But even before toying with relieving chambers and ascending passages, Hamunu or any other lead pyramid builders had to lay the foundations for their masterwork.

And even before that, they had to pick the right location. The ground had to be solid and level enough, and the site had to be easily reached via a supply line, preferably a natural or artificial waterway. More on this later. Next, the architect laid down the boundaries of the site, etching the lines of the pyramid sides on the ground. the sides. It usually ran in parallel to the north, south, and east, west axis, an alignment which ancient Egyptians achieved by tracking the movements of the sun to identify the true north. It was then time to dig the site and then lay down some solid foundations, which usually consisted of three layers of flat stones arranged without mortar or any form of cement. According to the already quoted Hamida and sandbul, this approach to foundations was probably conceived to absorb the shock of earthquakes. The next task for the Egyptian builders was to level the foundation, which they

could achieve with a great degree of accuracy. Kufu's pyramid, for example, is leveled to 2 cm or less than 1 in. There's no absolute certainty of how such precision could be insured, but there are two likely methods they used. Hamunu might have flooded the construction site with a shallow layer of water, and workers then leveled all foundational material rising above the water line. Alternatively, Hammunu might have divided the construction area into grid of squares, planting wooden posts where vertical and horizontal lines intersected. Laborers then stretch lines along the grid, keeping them at preset height. They then carve marks on the wooden post at the corresponding height and finally smoothed out any foundational material which rose above said marks. Now, Hemunu and other planners clearly did not do the grunt work by themselves, but employed scores of laborers and skilled craftsman who

contributed across all stages of the pyramid's building process. Quarrymen, stonemasons, metal workers, carpenters, as well as foremen leading teams of burly dudes in charge of moving big rocks around. to say nothing of the adjacent trades people who had to transport building material, cater for the workers, house them, treat their occupational mishaps, and eventually bury them if their injuries were a dead too catastrophic. As mentioned, Herodotus wrote that Kufu's pyramid had been built by a combined force of 100,000 laborers. But modern Egyptologists venture much smaller estimates. On this, estimates on the real size and nature of the workforce come courtesy of archaeologist Mark Leonard from Harvard University. Leonard and his team found evidence of not one but two towns near Giza laid out side by side. One of them appears to have grown organically little by little over time.

The archaeologists speculate that this town was erected to house a core contingent of permanent pyramid builders, a sort of company town for them and their families. It included food stores, temples, and public buildings which could have sustained a population between 2,000 and 5,000 laborers. The second town appeared more formal and laid out according to a rigid grid in which blocks of long galleries were separated by streets paved in limestone covered in mud and fitted with a drainage system. Archaeologists found a total of 40 sprawling galleries arranged into four large blocks, each some 170 m long. Barry Kemp, an expert in ancient Egyptian urbanism, found that each gallery presented the same feature of a typical Egyptian house, only on a huge scale. Moreover, the galleries were flanked by row upon row of bakeries, and the surrounding soil was littered with animal bones. Alongside these galleries,

Leonard and his team found more functional buildings, such as a storehouse for grain, a fish processing plant, and a workshop to produce the copper tools used by quarrymen and stonemasons. Leonard and Kemp thus concluded that the galleries acted as a sort of dormitories or barracks, which may have housed an army of up to 25,000 seasoned laborers and tradesmen, complimenting the permanent workforce living in the first town. The dormitories could have held a maximum of 2,000 people at one time, which suggests that temporary workers may have traveled to Giza from their place of residence, fulfilling shifts of 3 to 4 months before returning to their original occupation. All in all, Leonard estimates that up to 30,000 men in total may have built the Great Pyramid. A slow, methodical, constant process, which may have taken approximately 23 years. But numbers and time alone do not warrant the success of a building

project. What really matters is how the workforce is organized. Leonard's colleague, archaeologist Zahi Hawas, surveyed a cemetery dedicated to permanent laborers and their foremen, unearthing inscriptions revealing how they were organized. The overall workforce was divided into crews of no more than 2,000 people and each crew was further split into gangs of 1,000 identified by monikers such as the friends of Kufu or the drunkards of Manari. Then the gangs were divided into files, each numbering 200 men, and each file included 10 divisions of 20 laborers, and each division under its own project leader would take charge of a well-defined task. This quasi military coordination ensured that directions from the chief architect would be effectively cascaded down to the individual project leaders so that each division completed their allocated task without stepping onto each other's feet.

Of course, even when your foreman knows what he's doing, lifting giant blocks of limestone under the Egyptian sun does not exactly sound like a pleasurable task. Thus, it is fair to wonder, were these builders coerced in any way? Were they slaves? Egypt during the fourth dynasty definitely did rely on slave labor, but it appears that pyramid builders were free men. Specifically, Leonard's discoveries at Giza have highlighted how the workforce enjoyed good living conditions and were served with a rich, mouthwatering diet far above what slaves would have been given.

Also, amongst the ruins of the worker city, Leonard and his team found the remains of the oldest bakery ever found in Egypt. Harvard University paleobotonist Wilma Wetstrom analyzed plant remains at the site determining that the Egyptian bakers used barley and ammerwheat flour as ingredients. These culinary discoveries were complemented by fondel analyst Richard Reading at University of Michigan. Within the site, he analyzed thousands of animal bones belonging to ducks, pigs, sheep, goats, and cattle. Apparently, the cattle bones recovered suggested that prime cuts of beef were being prepared and served to the builders. What is more noteworthy about this is that the plane of Giza, even 4,000 years ago, was probably ills suited to cattle grazing. Therefore, the boines were probably raised further up north in more fertile regions of the Nile Delta before being transported to Giza. Evidence also suggests that

workers received a steady daily salary of 10 loaves of bread and one jug of beer. And as for their supervisors, they seem to have been compensated with hundreds of loaves and tens of jugs of fine Egyptian brew. However, as these goods are perishable, Leonard Hwas speculated that these rates may have been only indicative. It may be that builders received the equivalent of loaves and beer paid in the form of other goods or credits. Alternatively, builders and tradesmen may have performed their duties as a part of their buck. This was a type of service owed by all Egyptian subjects to people who stood above them in the social hierarchy. This was a temporary duty and even the highest civil servants owed Bach to their higherups. That's why even if Bach was not remunerated, it was far from being a form of surfom or slavery.

The discoveries of Leonard Hawas and other experts have clarified one of the many mysterious aspects behind pyramid building. They were built over long periods of time by thousands of skilled burly men fed with a high protein diet that would leave a bodybuilder drooling with envy. But muscles alone do not make huge buildings. And these guys needed the right material and in huge quantities. The most visible building components of the pyramids were gigantic limestone blocks, some weighing up to 15 tons. The builders obviously used the heavier blocks in the lower layers to provide stability, reserving the lighter ones weighing some 1.3 tons for the upper sections. Working only with massive cubes of limestone is impractical, however, and thus builders employed them only for the outer layers of each pyramid. The main core was built with small bricks made of baked mud interspersed with granite and basalt

slabs used mainly for the inner galleries. Everything from here was firmly held together by layer upon layer of a special mortar concocted according to a very effective recipe. Gypsum crystals, fragments of calsite and dolomite, quartz grains and everything cemented by finely grain gypsum and hydrate, calsite and iron oxides. Producing such mortar must have been an industry in itself considering how much of this stuff was required. In the case of the Great Pyramid, builders employed some 500,000 tons of ancient cement. On top of all the materials mentioned thus far, builders also laid an outer cladding, today only partially visible, which provided a smooth, glistening, final appearance to the assembled pyramids. The composition of this casing varied from pyramid to pyramid. In the case of Kufus, it was made entirely of calite, whereas for Manari's monument, craftsmen worked out a complex outer

layer made with pesh, feldspar, quartz, and zirkon among many other minerals. Very sensibly, most of the material we listed was sourced locally. The limestone blocks used for Kufu's Great Pyramid, for example, came from a quarry situated just 500 m or 547 yards south of the monument. Now, quarrying, cutting, and polishing such blocks was definitely a daunting endeavor without modern tools. But ancient Egyptians managed just as well without such nicities, relying only on patience, skill, hard work, and ingenuity. As for how they did it, this conundrum was addressed by analytical chemist and archaeologist Alfred Lucas in the 1920s when the concept that Egyptians had access to long-lost advanced technology was plain ludicrous. Through his research and practical experiments, Lucas concluded that ancient quarry men used an array of wooden stone and bronze tools to fracture limestone rock into

large sections. They were then shaped, cut, and polished by using bronze saws, chisels, and drills in conjunction with an abrasive mixture rich in corundum, a mineral composed of aluminum oxide. Builders use similar cutting and carving techniques to quarry other material aside from limestone, which by the way required an extra dose of blood, sweat, and tears as it had to be transported from further a field. The minerals used for the casing, for example, were picked up at the Macum Plateau, a 5hour march to the east of Giza, which was still just a walk in the oasis compared to the slabs used in the inner chambers. Basalt came from the Fi depression almost 100 km or 62 mi southwest of Giza. Alabaster had to be sourced from Luxer, some 630 km or 391 mi south. and the granite slabs likely came from asan more than 800 kilometers or almost 500 miles up the Nile. This problem with distance raises the next question. How did

laborers transport tons and tons of rock over such long distances? So, let's start with a relatively easy task, i.e. hauling limestone blocks from the quarry situated a half kilometer away from Giza. There is no definitive answer, but we have two very likely very practical candidates. Workers may have used large wooden wedges, each shaped like the quarter of a circle. These contraptions were attached to the corners of each limestone block, essentially rounding its edges. This way, a team of eight men could easily roll the block around, as you would do with a large barrel or keg.

But the more popular theory is that the blocks may have been simply loaded on top of wooden sleds and then dragged with rope. Japanese construction company Obayashi Corporation conducted an experiment demonstrating that just 18 men could use this technique to easily drag a 2.5 ton block at a speed of 18 minutes per mile. This task could have been made easier by employing a large squad and by pouring water or milk on the sand to act as a lubricant. Now, sleds, ropes, and muscles certainly work fine for short distances, but how about hauling these slabs of granite and other heavy rocks from hundreds of kilometers away? In that case, Egyptians could rely on their best non-human friend, the River Nile. All of the locations from which materials were sourced from Fum to Aswan are conveniently located near the shores of the Nile, making it relatively easy to load even heavy rocks onto the barge or any other shallow draft boat

and then sail down river. Of course, if you look at the current map of Egypt, you probably realize that the Giza Plateau is about 9 km or 5.6 6 milesi west from the nearest branch of the Nile, which is quite the distance to be dragging massive loads. But pyramid builders had not only enviable quads and guns, but they had even more enviable brains. And if they could spare themselves some extra sweat, they would. Rather than walking the last leg of the journey, they more likely exploited a pre-existing arm of the Nile, now defunct, which stretched further west towards Giza. Quoting from a 2022 paper by geoarchchaeologist Dr. Shasha at Xarse University. New paleoecological analysis have helped to reconstruct an 8,000-year fluial history of the Nile in this area, showing that the former watercapes and higher river levels around 4,500 years ago facilitated the construction of the Giza pyramid

complex. So, according to the good doctor, the Giza builders exploited higher water levels to dig a network of canals and basins culminating in a port complex at the very foot of the Giza plateau. This artificial harbor was likely the setting of a lively trade consisting mainly of small vessels which transported lighter materials, supplies, and workers. During the flood season, in contrast, from August to October, the water levels in the port complex rose up to 7 m or 23 ft, allowing for the docking of larger cargo ships. More recent studies indicate that the Nile was the backbone of the construction of the pyramids across all of Egypt, not just at Giza. In May of 2024, geomorphologist Dr. Emmen Gonim and her team at University of North Carolina Wilmington announced the discovery of a lost branch of the Nile now dry and covered by sand and farmland. By using radar satellite imagery, historical maps

and sediment cing, Dr. Gonim and team were able to trace the path of this lost branch, which they named Aramat after the Arabic word for pyramid. The Aramat branch extended for some 64 km or 39 mi flowing from south to north roughly in parallel to the main course of the Nile. By looking at a map of the Aramat, it is apparent how it bordered several pyramid sites from Lis down south and the north to Dasher, Sakara, Abuser, and eventually Giza. All in all, the lost branch may have contributed to the construction of 31 pyramids before drought and sandstorms caused its disappearance. So once all the material was sourced, it was time to put it all together, which raises the next big question. How could blocks weighing at least 1.3 tons be hoisted up a structure taller than 100 m? Once again, we can find some early answers from ancient historians. Diodoris Cicholus wrote that the construction was undertaken with the

help of ramps of earth. Egyptologists generally accept this concept and archaeological evidence has proved that ramps of earth, gravel and bricks were in fact used by Egyptians at several construction sites. One of the best examples comes from the temple of Carac where a mud brick ramp still stands. Other inclined walkways were found next to an early unfinished step pyramid at Aidas likely commissioned by Pharaoh Hunu Kufu's grandfather. And in 2018, a joint team from the French Institute for Oriental Archaeology and the University of Liverpool uncovered the remains of a ramp at the Hatnam Alabaster Quarry fitted with post holes all the way up the structure. The use of wooden posts suggests that workers may have tied ropes around them and then pulled down said ropes to haul alaster slabs up the ramp. So, all evidence seems to be that the builders probably first loaded limestone blocks, slabs, or other

materials onto sleds. Then these sleds were pulled up the ramps by using the ropes tied around the posts. Other teams of workers may have helped by pulling directly at the sleds while pouring water or milk to lubricate the surface of the ramp. The ramps unearthed by scholars, however, do not clarify what the ramps employed at the Giza site exactly looked like. Egyptologist Flenders Petri writing in the early 1880s speculated that workers employed a single long and straight ram climbing to the top of the pyramid which then turned in a zigzag shape near the summit.

However, his German colleague, Uvo Haler, writing in 1912, found it more likely that the ramps zigzagged all the way from the base to the top. Another German archaeologist, Dier Arnold, proposed yet again a straight ramp, but one that would cut through the middle of the pyramid itself. As for our good friends, Leonard Hanoas, they placed their bets on a long winding spiraling ramp twisting around the exterior of the monument. In 2005, French architect Jean Pierre Hudin proposed an alternative to the spiral concept. In his view, the ramp may have been placed inside the pyramid. If that were the case, a ramp could still be present inside the Great Pyramid itself. Indeed, one study using a technique called microgravimetry revealed CG images consistent with an internal ramp. However, a later study conducted by the scan pyramid mission found no evidence of the structure, thus seemingly disproving Hudin's theory.

Whatever their configuration, ramps still stand as the most likely way they got the blocks up there. But Leonard Hawas raised an important conundrum. As one approaches the apex of the pyramid, the sides of the geometrical shape get narrower and narrower. Towards the top, builders will have run out of room to lay out their ramps, which implies that they needed to employ more sophisticated techniques to hoist their blocks. According to the two scholars, it is very possible that levering was the only means to raise the blocks to the highest courses near the apex once the builders had brought them as high as they could on the ramps. And note on this, the use of levers or more complex machines had been described as early as 425 BC by good old Heroditus. They raised the remaining stones with machines made of short pieces of timber, raising them first from the ground to the first stage of the steps. And when the stone got up

to this, it was placed upon another machine standing on the first stage. And so from this, it was drawn to the second upon another machine. While the description is not entirely clear, this could be interpreted as Egyptians using a seessaw-like machine made of wooden beams on which they placed counterweights to raise the blocks. According to researchers such as Smers Clark, author of ancient Egyptian construction and architecture, ramps and seesaw contraptions were complemented by the ample use of scaffolding. The area of the Nile Delta was and still is very fertile, which allowed Kufu subjects to grow and exploit some sturdy timber from date palms, acacia, sycamore, and other trees, which were routinely used to build big boats or big solid temple doors. Besides this, Kufu's dad Nephu had established trade routes with modern-day Lebanon, contributing to the import of cedarwood, even better suited

for scaffolding purposes. Also, in this case, scholars are not entirely aligned on how and why scaffolding may have been used. According to engineer James Frederick Edwards in his paper, Building the Great Pyramid: Probable Construction Methods employed at Giza, scaffolds were used by the most skilled masons at the very end of the construction process. Perched at top the wooden beam and platforms, these laborers applied the final gleaming layers of white limestone cladding. And it's at this point we like to think those indeafitable builders enjoyed some barbecued beef and a cool beer at top their scaffolds while enjoying the sight of the last rays of the setting sun bouncing off the apex of the perfectly finished pyramid while similarly reflecting off the silver flying saucers flitting away to the stars in the distance with said saucers occupants likewise pleased with what they'd helped the humans accomplish in

the pyramids. On that note, while of course there is still some mystery as to exactly how every facet of the pyramid construction was accomplished, what we have, however, is a collection of very realistic theories supported by archaeological findings and field experiments which attest that Egyptian builders had at their disposal a vast array of resources, skills, tools, and techniques to erect some veritable wonders of the ancient world. No ancient aliens required, and indeed had there been, we'd have hoped for structures a bit more advanced from what came before.

And speaking of what came before, contrary to popular belief, this vast engineering knowledge did not materialize overnight. Egyptian architects and builders developed their methods over easily perceivable centuries of painstaking work by making the most of the resources they had at their disposal, such as local quaries or now dried up branches of the Nile. Along the way, these indomitable constructors of marbvels played around with some pretty basic designs and stumbled upon some embarrassing fails. But they were able to learn from these experiences and hone their increasingly ambitious techniques propelling the development of their society along the way. To paraphrase Mark Leonard, the development of such techniques and the marshalling of enormous resources required by the pyramids did not just impact the building trade, but contributed to shaping Egyptian civilization itself.

Questions about this episode

Who speaks in "What Actually Happened to the Sphinx's Nose? What was the Real Antikythera Mechanism Used for & More"?

Simon (Guest), Mark Leonard (Guest), Thomas Young (Guest), Dr. Zia Ass (Guest), Luis Farrakhan (Guest), Arthur Ree (Guest), Derek Dola Price (Guest).

What is "What Actually Happened to the Sphinx's Nose? What was the Real Antikythera Mechanism Used for & More" about?

The Great Sphinx of Giza, an iconic monument over 4,500 years old, remains shrouded in mystery regarding its origins, purpose, and the fate of its missing nose, which is often attributed to popular misconceptions. While traditionally believed to have been built during Pharaoh Kafra's reign as part of an elaborate temple complex, recent insights suggest its construction was somewhat accidental…

What is mentioned in this Today I Found Out episode?

18 people, works and ideas are mentioned, including Kafra, Mark Leonard, Antikythera mechanism, Derek Dola Price, Curtis Wayne Wright, Abu Simbel. Each one on this page links to its own page with every episode that mentions it.

How long is "What Actually Happened to the Sphinx's Nose? What was the Real Antikythera Mechanism Used for & More"?

The episode runs 1 h 41 min; the transcript is about 18,393 words in 131 timestamped sections.

More from Today I Found Out

About this transcript: the episode's spoken words as captioned on YouTube, split into timestamped sections. Reclip.Me locates every person, work and idea in the text, keeps the time it is first named, and quotes the words around it verbatim. Last updated January 24, 2026.