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How Did Egyptians Move Heavy Rocks For The Pyramids?

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The pyramids aren't just old, they're really really old: We are closer in time to Cleopatra than she was to the building of the first pyramids. That mind-boggling time-chasm might explain why the pyramids have proved to be a source of fascination and speculation for modern humans, who can't imagine how our ancient forefathers got anything done without technology, let alone building structures large enough to be seen from space.

Stacking the blocks into the towering iconic shape is often marveled at as a feat of mystery, but just assembling the necessary materials is equally miraculous.

For the Great Pyramid of Giza—which is thought to have been built over a span of two decades for fourth dynasty pharaoh Khufu—over 2,300,000 giant blocks of limestone and granite weighing an average of two and a half tons had to be transported to the site from quarries—some from places like Aswan, more than 500 miles away.

Archeological evidence suggests that the ancient Egyptians used crude wooden sleds to transport the heavy building blocks. But if you've ever dragged something through the sand, you can understand why these sleds might not have eased this task. The weight of the blocks would cause the sled to sink slightly and, as you dragged them, sand would accumulate in front of the sled, increasing the resistance.

A recent study in the journal Physical Review Letters proposes an explanation for how the Egyptians made use of the sleds that is based on a principle most people are familiar with: While dry sand is easily pushed around, wet sand is malleable but more rigid. This is why you need moist sand to give your sandcastles structural integrity at the beach. The correct ratio of water to sand—which is variable, but typically between 2 percent and 5 percent of the volume of sand—causes the water droplets to create capillary bridges that bind the individual grains of sand into a smoother, stronger surface.

In experiments, the force required to pull sleds across sand was reduced by a full 50 percent when the right amount of water was added. Not only would it make sense for the ancient Egyptians to have utilized this tactic, there's evidence to suggest that they did. A wall painting from the tomb of Djehutihotep shows a hoard of workers moving a statue of the Upper Egypt nomarch on a sled. While rows of workers are shown heaving heavy ropes attached to the statue, a single figure is painted perched atop the sled pouring what could certainly be water on to the ground in front of him.

"In fact, Egyptologists had been interpreting the water as part of a purification ritual, and had never sought a scientific explanation," Daniel Bonn, who led the study, told the Washington Post.

The science is sound, but that doesn't necessarily mean it overrules the Egyptologists' theories about Djehutihotep's wall painting or that it applies to the pyramids, which were built over 600 years before Djehutihotep lived. Most reports of the study have assumed that applying their findings to the pyramids is something of a foregone conclusion. Adding water to the sand to decrease friction certainly makes sense, but that doesn't necessarily mean it's what the Egyptians did.

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Stones, Bones, and Wrecks
Scientists Discover a Mysterious Void in the Great Pyramid of Giza
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The Great Pyramid of Giza, the largest in all of Egypt, was built more than 4500 years ago as the final resting place of the 4th Dynasty pharaoh Khufu (a.k.a. Cheops), who reigned from 2509 to 2483 BCE. Modern Egyptologists have been excavating and studying it for more than a century, but it's still full of mysteries that have yet to be fully solved. The latest discovery, detailed in a new paper in the journal Nature, reveals a hidden void located with the help of particle physics. This is the first time a new inner structure has been located in the pyramid since the 19th century.

The ScanPyramids project, an international endeavor launched in 2015, has been using noninvasive scanning technology like laser imaging to understand Egypt's Old Kingdom pyramids. This discovery was made using muon tomography, a technique that generates 3D images from muons, a by-product of cosmic rays that can pass through stone better than similar technology based on x-rays, like CT scans. (Muon tomography is currently used to scan shipping containers for smuggled goods and image nuclear reactor cores.)

The ScanPyramids team works inside Khufu's Pyramid
ScanPyramids

The newly discovered void is at least 100 feet long and bears a structural resemblance to the section directly below it: the pyramid's Grand Gallery, a long, 26-foot-high inner area of the pyramid that feels like a "very big cathedral at the center of the monument," as engineer and ScanPyramids co-founder Mehdi Tayoubi said in a press briefing. Its size and shape were confirmed by three different muon tomography techniques.

They aren't sure what it would have been used for yet or why it exists, or even if it's one structure or multiple structures together. It could be a horizontal structure, or it could have an incline. In short, there's a lot more to learn about it.

In the past few years, technology has allowed researchers to access parts of the Great Pyramid never seen before. Several robots sent into the tunnels since the '90s have brought back images of previously unseen areas. Almost immediately after starting to examine the Great Pyramid with thermal imaging in 2015, the researchers discovered that some of the limestone structure was hotter than other parts, indicating internal air currents moving through hidden chambers. In 2016, muon imaging indicated that there was at least one previously unknown void near the north face of Khufu's pyramid, though the researchers couldn't identify where exactly it was or what it looked like. Now, we know its basic structure.

A rendering shows internal chambers within the Great Pyramid and the approximate structure of the newly discovered void.
ScanPyramids

"These results constitute a breakthrough for the understanding of Khufu's Pyramid and its internal structure," the ScanPyramids team writes in Nature. "While there is currently no information about the role of this void, these findings show how modern particle physics can shed new light on the world's archaeological heritage."

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For the First Time in 40 Years, Rome's Colosseum Will Open Its Top Floor to the Public
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The Colosseum’s nosebleed seats likely didn’t provide plebeians with great views of gladiatorial contests and other garish spectacles. But starting in November, they’ll give modern-day tourists a bird's-eye look at one of the world’s most famous ancient wonders, according to The Telegraph.

The tiered amphitheater’s fifth and final level will be opened up to visitors for the first time in several decades, following a multi-year effort to clean, strengthen, and restore the crumbling attraction. Tour guides will lead groups of up to 25 people to the stadium’s far-flung reaches, and through a connecting corridor that’s never been opened to the public. (It contains the vestiges of six Roman toilets, according to The Local.) At the summit, which hovers around 130 feet above the gladiator pit below, tourists will get a rare glimpse at the stadium’s sloping galleries, and of the nearby Forum and Palatine Hill.

In ancient Rome, the Colosseum’s best seats were marble benches that lined the amphitheater’s bottom level. These were reserved for senators, emperors, and other important parties. Imperial functionaries occupied the second level, followed by middle-class spectators, who sat behind them. Traders, merchants, and shopkeepers enjoyed the show from the fourth row, and the very top reaches were left to commoners, who had to clamber over steep stairs and through dark tunnels to reach their sky-high perches.

Beginning November 1, 2017, visitors will be able to book guided trips to the Colosseum’s top levels. Reservations are required, and the tour will cost around $11, on top of the normal $14 admission cost. (Gladiator fights, thankfully, are not included.)

[h/t The Telegraph]

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