"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.
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. Davidovits claimed that the stones of the pyramids were actually made of a very early form of concrete created using a mixture of limestone, clay, lime, and water."
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