All of the current theories -- a long, straight ramp, a ramp that corkscrewed around the outside of the pyramid, or cranelike shadoufs (used in Egypt until recently for irrigating fields) -- have serious flaws... architect Jean-Pierre Houdin and I presented a radical new theory: that blocks of stone were raised to the very top of the pyramid on an internal ramp. We gave what we felt was strong evidence for the theory, which explains a French team's microgravemetric survey in the 1980s that recorded variations in the density of the pyramid... an image from the survey may show a...