if the pyramids are solid and not hollow (I admit I don't know) then there is truly a lot of stone there and still nobody has come up with a calculation for how many men would be needed to lift the blocks and how they did it, how did they have implements capable of such weight, funny isn't it the ancient civilizations used huge stones, all those that came after standard bricks like we still do why not use smaller bricks it would have been simpler, all those people that quaried and transported the blocks needed feeding not to mention building the so called ramps ecc and then hauling them up and positioning them it was not just a case of digging the stone and dragging it there they needed to be placed as well