by Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on exciting discoveries, scientific advances and more.
For years, Egyptologists have hotly debated how the giant pyramids of ancient Egypt were built more than 4,000 years ago. Now, a team of engineers and geologists brings a new theory to the table – a hydraulic lift device that would float the heavy stones up through the center of Egypt’s oldest pyramid using stored water.
The ancient Egyptians built the Step Pyramid for Pharaoh Djoser in the 27th century BC, and was the tallest structure at the time, coming in at around 62 meters (204 feet) in height. But how exactly the monument was built, with several stones weighing in at 300 kilograms (about 661 pounds), remains a centuries-old mystery, according to the study published Monday in the journal PLOS One.
“Many publications have discussed detailed pyramid building procedures and provided tangible features, but these tend to focus on the later, better-documented, and smaller pyramids of the Middle and New Kingdoms (1980 to 1075 BC ),” said lead author Dr. Xavier Landreau, CEO of Paleotechnic, a privately owned research institute in Paris that studies ancient technologies.
“These techniques may include ramps, cranes, boots, toggle lifts, lifts, pivots, or a combination of these methods,” he said in an email. “But what about the Old Kingdom pyramids (2675 to 2130 BC), which are much larger? While human strength and ramps may have been the only building force for small structures, other techniques may have been used for large pyramids.”
Using an interdisciplinary approach, the new paper was the first to report a system consistent with the internal architecture of the Step Pyramid, the authors wrote.
A complex water treatment system drawing on local resources would have left a water-driven lift within the pyramid’s internal vertical shaft. Some kind of float would have lifted the heavy stones up the middle of the pyramid, according to the study.
Although the theory is an “ingenious solution”, some Egyptologists are not convinced, as the more widely believed theory is that the ancient Egyptians used ramps and carts to move the heavy blocks in place, said Egyptologist Dr David Jeffreys, retired. senior lecturer in Egyptian archeology at University College London who was not involved in the study. Here’s what experts have to say about the new theory.
The Egyptian desert was once Savannah
By analyzing available data, including paleoclimatology, studies of ancient climates and archaeological data, the study team suggested that water from ancient streams flowed from the west of the Saqqâra plateau into a system of deep water trenches and tunnels that surrounded the Step Pyramid.
The water would also flow into the Gisr el-Mudir – a massive rectangular limestone structure measuring 650 by 350 meters (2,133 ft by 1,148 ft) – which acted as a check dam. This device, previously thought to be a fortress, a place of celebration or a cattle enclosure, would control and store water from heavy floods, as well as filter sediment and dirt so that they would not clog the water passages.
The theorized water treatment system would not only allow for water control during floods, but would also ensure “adequate quality and quantity of water for consumption and irrigation purposes and for transport or construction,” said study co-author Dr. Guillaume Piton. researcher. with the French National Research Institute for Agriculture, Food and the Environment, or INRAE, which is based at the Institute of Environmental Geosciences of the University of Grenoble Alpes.
The authors noted several previous studies that found that the Sahara desert had more regular rainfall thousands of years ago than it does today. Rather, the landscape would resemble a Savannah, which could support more plant life than harsh desert conditions. However, there is debate as to exactly when the climatic conditions were wetter.
There may have been enough water to support a system like the hydraulic lift, said Dr. Judith Bunbury, a geoarchaeologist at the University of Cambridge in London who was not involved in the new study. She cited past research that found that rainwater gutters were being built and used in the Old Kingdom, as well as past research that looked at the diet of birds in over time, which consisted of wetland species such as frogs.
“I think there’s a fairly widespread belief that it was rainier in the Old Kingdom, certainly in the early Old Kingdom when the Step Pyramid was being built,” she said.
On the other hand, experts debate whether there would have been enough steady rainfall to fill the structures supporting the hydraulic lift, such as the “Dry Moat,” a huge channel that surrounds the Step Pyramid and nearby structures. The authors believe that water collected helped power the elevator when it was in use.
The greener period of the Sahara probably ended at the beginning of the third millennium BC, according to Jeffreys. The low rainfall would not be able to fill the structures to the extent necessary for a hydraulic lift, and furthermore it would not be able to keep up with the loss of water within the structure’s limestone, said Dr Fabian Welc, director of the Archaeological Institute. at Cardinal Stefan Wyszynski University in Warsaw, Poland. Welc was not involved in the new study.
“There was a wetting of the climate (seasonal – winter rains) in northern Egypt (also in Saqqāra) during the 3rd Dynasty (2670-2613 BC), but their intensity was relatively low. These rains, even filling the wadis (dry valley except in rainy seasons) with water, would not be able to fill the dry moat even to a small extent… these waters would be drained immediately by gravity deep into the massif rock, which is beyond doubt (unless it was a biblical flood),” Welc said in an email.
The authors of the study agreed that it was unlikely that the system was permanently filled with water and argued that it is more likely that the flash floods of the moment could have provided enough water to support the hydraulic lift during construction of the pyramid. However, more research is still needed to know exactly how much rain and flooding likely occurred during this time, the authors noted in the study.
This is not the first time that the Nile has been investigated to see if it played a role in the construction of the pyramids. A study published in May found a dried-up branch of the giant river and theorized that the stream was likely used to transport huge blocks of limestone to multiple pyramid construction sites. There is also some evidence that the ancient Egyptians were using hydraulics on a smaller scale, Jeffreys said.
The mystery of ancient Egyptian structures
Previous researchers have not determined a clear purpose for the vertical shaft within Djoser’s pyramid. In some later pyramids, such as the Great Pyramid of Giza, shafts are believed to have been used for ventilation, and the inner shaft may have been intended for lighting or to relieve pressure on the room below, Jeffreys said. But as the first of its kind, the Step Pyramid was an experimental structure believed to have started out as a mastaba (flat tomb) and was built up, so it is not clear exactly what its internal features were, he said. he. .
The shaft inside the Step Pyramid is connected to a 200-metre long (656 ft long) underground tunnel which connects to another vertical shaft outside the pyramid. The outer shaft could then connect to a hypothetical water-bearing part of the Dry Hill, called the Deep Trench, but more research is needed, the authors wrote in the study.
The inner shaft begins just below the pyramid near the center where a granite box sits with a plug at its base. This box is widely believed to be the burial chamber of King Djoser, but instead, the authors suggest that it was built to open and close the hydraulic lift, allowing water to fill the shaft when it is in use.
As for whether other pyramids were built using this method, Landreau said further investigation is needed. “Perhaps he holds the key to the mystery of the greatest monoliths, found in pyramids such as Khufu or (Khephren) raised. These monoliths weigh thousands of tons, making it apparently impossible to drag them using only (human labor). Conversely, a medium-sized hydraulic lift can lift 50 to 100 tons. “Exploring hidden shafts within these pyramids could be a great avenue of research,” he said.
Despite the more than 4,000-year-old mystery surrounding the pyramids and features, there is sufficient documentation that the ancient Egyptians used certain technologies such as scaffolding and mud-brick ramps to help build various structures, said geoarchaeologist University of Cambridge Bunbury. , although there is no documentation or illustration of a water-powered lifting device to her knowledge.
“I think people, even since then, have been inspired by the pyramids as a massive building project,” Bunbury said. “And it’s very hard for them to believe that they were raised by ordinary people at that time, partly because they see it as it was a long time ago. … It’s remarkable that there are so many proposals for possible technological innovation that have been shelved again, when we know they had technical solutions to these things anyway.
“It doesn’t mean (the hydraulic lift device) wasn’t used,” she said. “But such Occam’s razor is the simplest thing based on what we already know.”
For more CNN news and newsletters create an account at CNN.com
