for National Geographic News
Ancient Egyptians built the 480-foot-high (146-meter-high) Great Pyramid of Giza from the inside out, according to a French architect.
Based on eight years of study, Jean-Pierre Houdin has created a novel three-dimensional computer simulation to present his hypothesis. He says his findings solve the mystery of how the massive monument just outside Cairo was constructed.
The 4,500-year-old tomb of Pharaoh Khufu, he concluded, was built using a ramp that spirals around the pyramid's interior 30 to 45 feet (9 to 14 meters) behind the exterior surface (see image at left).
"I am completely comfortable with this theory," Houdin said in a telephone interview from Paris. He was in the French capital on Friday to show the simulation to 400 spectators wearing 3-D goggles.
Previous theories have suggested that builders on Egypt's Giza Plateau hoisted the pyramid's millions of multi-ton stone blocks using an external ramp.
(Related: "Pyramid Builders' Village Found in Egypt" [September 18, 2002].)
Such a structure either corkscrewed around the pyramid's outer surface or grew in a straight line with the pyramid, the theories contend.
Houdin's theory posits that a long, straight ramp was used to build the first 129 feet (39 meters) of the pyramid and the internal ramp was used to complete construction.
Drawings from a 1986 survey of the pyramid show a "spiral anomaly" inside that conforms exactly to this theory, he said.
Houdin and French computer-imaging firm Dassault Systemes spent two years building a computer model to test the hypothesis.
"We have done it in the 3-D world," he said. "The virtual pyramid is the same as the [real-life] Giza pyramid."
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