The Surprising Truth About How the Great Pyramids Were Built | Sheila Berninger & Dorilona Rose | livescience.com | originally published May 18, 2007
This Behind the Scenes article was provided to LiveScience in partnership with the National Science Foundation.
“This is not my day job,” begins Michel Barsoum as he recounts his foray into the mysteries of the Great Pyramids of Egypt. As a well respected researcher in the field of ceramics, Barsoum never expected his career to take him down a path of history, archaeology, and “political” science, with materials research mixed in.
As a distinguished professor in the Department of Materials Science and Engineering at Drexel University, his daily routine consists mainly of teaching students about ceramics, or performing research on a new class of materials, the so-called MAX Phases, that he and his colleagues discovered in the 1990s. These modern ceramics are machinable, thermal-shock resistant, and are better conductors of heat and electricity than many metals — making them potential candidates for use in nuclear power plants, the automotive industry, jet engines, and a range of other high-demand systems.
Then Barsoum received an unexpected phone call from Michael Carrell, a friend of a retired colleague of Barsoum, who called to chat with the Egyptian-born Barsoum about how much he knew of the mysteries surrounding the building of the Great Pyramids of Giza, the only remaining of the seven wonders of the ancient world.
The widely accepted theory — that the pyramids were crafted of carved-out giant limestone blocks that workers carried up ramps — had not only not been embraced by everyone, but as important had quite a number of holes.
Burst out laughing
According to the caller, the mysteries had actually been solved by Joseph Davidovits, Director of the Geopolymer Institute in St. Quentin, France, more than two decades ago.
“It was at this point in the conversation that I burst out laughing,” Barsoum said. If the pyramids were indeed cast, he said, someone should have proven it beyond a doubt by now, in this day and age, with just a few hours of electron microscopy.
It turned out that nobody had completely proven the theory … yet.
“What started as a two-hour project turned into a five-year odyssey that I undertook with one of my graduate students, Adrish Ganguly, and a colleague in France, Gilles Hug,” Barsoum said.
The stones also had a high water content — unusual for the normally dry, natural limestone found on the Giza plateau — and the cementing phases, in both the inner and outer casing stones, were amorphous, in other words, their atoms were not arranged in a regular and periodic array. Sedimentary rocks such as limestone are seldom, if ever, amorphous.
The sample chemistries the researchers found do not exist anywhere in nature. “Therefore,” Barsoum said, “it’s very improbable that the outer and inner casing stones that we examined were chiseled from a natural limestone block.”
More startlingly, Barsoum and another of his graduate students, Aaron Sakulich, recently discovered the presence of silicon dioxide nanoscale spheres (with diameters only billionths of a meter across) in one of the samples. This discovery further confirms that these blocks are not natural limestone.
At the end of their most recent paper reporting these findings, the researchers reflect that it is “ironic, sublime and truly humbling” that this 4,500-year-old limestone is so true to the original that it has misled generations of Egyptologists and geologists and, “because the ancient Egyptians were the original — albeit unknowing — nanotechnologists.”
As if the scientific evidence isn’t enough, Barsoum has pointed out a number of common sense reasons why the pyramids were not likely constructed entirely of chiseled limestone blocks.
Although Barsoum’s research has not answered all of these questions, his work provides insight into some of the key questions. For example, it is now more likely than not that the tops of the pyramids are cast, as it would have been increasingly difficult to drag the stones to the summit.
Also, casting would explain why some of the stones fit so closely together. Still, as with all great mysteries, not every aspect of the pyramids can be explained. How the Egyptians hoisted 70-ton granite slabs halfway up the great pyramid remains as mysterious as ever.
“How energy intensive and/or complicated can a 4,500 year old technology really be? The answer to both questions is not very,” Barsoum explains. “The basic raw materials used for this early form of concrete — limestone, lime, and diatomaceous earth — can be found virtually anywhere in the world,” he adds. “Replicating this method of construction would be cost effective, long lasting, and much more environmentally friendly than the current building material of choice: Portland cement that alone pumps roughly 6 billion tons of CO2 annually into the atmosphere when it’s manufactured.”
“Ironically,” Barsoum said, “this study of 4,500 year old rocks is not about the past, but about the future.”
More to Explore
- Michel Barsoum’s pyramid Web site
- Department of Materials Science and Engineering website
- A presentation on the pyramid discoveries by Michel Barsoum
Editor’s Note: This research was supported by the National Science Foundation, the federal agency charged with funding basic research and education across all fields of science and engineering.
ENGINEERING THE PYRAMIDS SPECIAL PROJECT | Drexel University
Professor Michel Barsoum and colleagues have found scientific evidence that parts of the Great Pyramids of Giza were built using an early form of concrete, debunking an age old myth that they were built using only cut limestone blocks.
SEM Micrographs and Elemental Maps from Bulk Pyramid Sample
- Dr. Barsoum’s Research Paper in the Journal of the American Ceramic Society
- Geopolymer White Paper
IN THE NEWS
- BBC Future: Will the Skyscrapers Outlast the Pyramids? (8/9/2016)
- Article in Chemical & Engineering News
- NSF.gov Discoveries: The Surprising Truth Behind the Construction of the Great Pyramids
- Behind the Scenes @ LiveScience.com
- Barsoum’s Pyramid Research Continues to be Syndicated
- French television clip 1
- French television clip 2
- Slashdot: Pyramid Stones Were Poured, Not Quarried
- Nature: Research Highlights
- NewScientist: Concrete evidence in Giza’s pyramids
- Rediff.com: Pyramids were built with concrete
- Solving the Mysteries of the Pyramids
How the Great Pyramids of Giza were built has remained an enduring mystery. In the mid-1980s, Davidovits proposed that the pyramids were cast in situ using granular limestone aggregate and an alkali alumino-silicate-based binder. Hard evidence for this idea, however, remained elusive. Using primarily scanning and transmission electron microscopy, we compared a number of pyramid limestone samples with six different limestone samples from their vicinity. The pyramid samples contained microconstituents (μc’s) with appreciable amounts of Si in combination with elements, such as Ca and Mg, in ratios that do not exist in any of the potential limestone sources. The intimate proximity of the μc’s suggests that at some time these elements had been together in a solution. Furthermore, between the natural limestone aggregates, the μc’s with chemistries reminiscent of calcite and dolomite—not known to hydrate in nature—were hydrated. The ubiquity of Si and the presence of submicron silica-based spheres in some of the micrographs strongly suggest that the solution was basic. Transmission electron microscope confirmed that some of these Si-containing μc’s were either amorphous or nanocrystalline, which is consistent with a relatively rapid precipitation reaction. The sophistication and endurance of this ancient concrete technology is simply astounding.
- Microstructural Evolution of Calcium-Doped α-AluminaArzu Altay, Mehmet Ali GülgünJournal of the American Ceramic Society
- Lime Refractories with Limestone and Synthetic Calcium Hydroxide AdditionsLana L. Wong, Richard C. BradtJournal of the American Ceramic Society
- LIMESTONE FOR SHEET GLASS MAKINGEdwin P. ArthurJournal of the American Ceramic Society
- More Insight from Physics into the Construction of the Egyptian PyramidsH. J. de HaanArchaeometry
- The “Djedi” Robot Exploration of the Southern Shaft of the Queen’s Chamber in the Great Pyramid of Giza, EgyptRobert Richardson, Shaun Whitehead, TC Ng, Zahi Hawass, Andrew Pickering, Stephen Rhodes, Ron Grieve, Adrian Hildred, Arjun Nagendran, Jason Liu, William Mayfield, Mehdi Tayoubi, Richard BreitnerJournal of Field Robotics