“This is not my day job.” So 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.“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 says.
A year and a half later, after extensive scanning electron microscope (SEM) observations and other testing, Barsoum and his research group finally began to draw some conclusions about the pyramids. They found that the tiniest structures within the inner and outer casing stones were indeed consistent with a reconstituted limestone. The cement binding the limestone aggregate was either silicon dioxide (the building block of quartz) or a calcium and magnesium-rich silicate mineral.
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,” says Barsoum, “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.”
Why do the results of Barsoum’s research matter most today? Two words: earth cements.
“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,” says Barsoum, “this study of 4,500 year old rocks is not about the past, but about the future.”
Source: Yahoo News
Image: Flickr/Meeshosaur
Tags: Construction | Pyramid
Comments