Photo: Asem Salama / Scientific Reports..
A diagram of the inside of the Great Pyramid of Giza in Egypt.
Today’s story about the brilliant design of the the Great Pyramid of Giza reminds me that people living in the 21st century should never assume they are more intelligent than people centuries ago. Many of our ethical stances show improvement. We have advanced gadgets and skills. But we have lost ancient skills needed to manipulate ancient gadgets.
And what about building construction? The high rise in New York City that threatens to collapse is surely an example of inferior design capability.
Compare that to the pyramids. Richard Widdington writes at Artnet, “Over the past 4,600 years, the Great Pyramid of Giza has weathered a dozen or so major earthquakes. … Cumulatively, seismic activity is one factor that explains why the structure has lost around 30 feet in height since it was completed at the peak of Egypt’s Old Kingdom.
“Otherwise, the wonder of the ancient world has endured relatively unscathed. Unlike the earlier Step Pyramid at Saqqara or the aptly named Bent Pyramid at Dahshur, the Great Pyramid of Giza is free from earthquake-induced structural damage. A new study led by seismologists at Egypt’s National Research Institute of Astronomy and Geophysics measured such resilience and concluded that it might be partly by design.
“[Researchers] used an accelerometer to measure natural vibrations at 37 locations inside and around the pyramid, including on its exterior stones, within its chambers, and in the surrounding soil. They found the majority of the vibrations inside the structure exhibited ‘exceptional homogeneity’ and ranged between 2.0 and 2.6 hertz. This means the stress of an earthquake is distributed evenly throughout the pyramid. Crucially, this differed from the surrounding soil, which averaged 0.6 hertz, effectively offering the ground as a natural shield that prevents seismic energy from amplifying as it passes into the monument. Building on top of a carefully leveled limestone bedrock, researchers noted, also helped to anchor the structure. The results were published in Scientific Reports in May.
“ ‘The Great Pyramid behaves as a single, cohesive unit that naturally vibrates at a fundamental frequency of approximately 2.3 Hz,’ one of the researchers, Asem Salama, said over email. ‘The frequency difference prevents the destructive phenomenon of resonance, the primary culprit behind the collapse of modern buildings, when a structure’s frequency matches the earthquakes vibrations.’
“Another factor preventing shockwaves from amplifying as they rise through the pyramid is a series of five rooms built directly above the King’s Chamber, which sits at the heart of the structure. Known as weight-relief chambers, they were designed to protect the hallowed space from the immense weight of the stone blocks above it. In the context of earthquakes, however, they act as a built-in ‘shock absorbers,’ diminishing the vibrations that reach them.
“Last, there’s the Great Pyramid of Giza’s most visibly obvious advantage: its bottom-heavy, symmetrical shape. This ensures weight and stress are distributed evenly throughout the structure.
“ ‘The earthquake resilience of the Great Pyramid of Giza is not a historical fluke, but the pinnacle of an ancient engineering evolution,’ Salama said. ‘Much like modern engineering advances through iterative science and lessons learned from past structural failures, Egyptian architects refined their techniques over generations. Prior disasters, such as the collapse of the Meidum Pyramid, provided critical data. By the time the Great Pyramid’s architects broke ground, they had mastered the physics of permanence.’ ”
More at Artnet, here. No firewall.
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