Just add water!
New evidence has been discovered explaining how the Pyramids of Giza were really built, dismissing rumours that it was cats, or aliens, or Sisi. The question of how our ancient civilisation managed to move about 2.5 tonne stones has long plagued scientists, engineers and Egyptologists a like but a team from the University of Amsterdam seem to have figured it out, possibly after a long hotbox session.
It's known that large sleds would carry the stones from the quarry to the site where the Pyramids were being built but of course no amount of Jews, or cats would have the strength to do that, as the sleds would eventually dig into the sand ahead of it, building up a sand berm that must then be regularly cleared before it can become an even bigger obstacle.
The solution they say was wet sand. With just the right amount of dampness, capillary bridges - microdroplets of water that bind grains of sand to one another through capillary action - would form across the grains, which doubles the material's relative stiffness. This prevents the sand from berming in front of the sled and cuts the force required to drag the sled in half.
The University of Amsterdam press release explains,
The physicists placed a laboratory version of the Egyptian sledge in a tray of sand. They determined both the required pulling force and the stiffness of the sand as a function of the quantity of water in the sand. To determine the stiffness they used a rheometer, which shows how much force is needed to deform a certain volume of sand.
Experiments revealed that the required pulling force decreased proportional to the stiffness of the sand...A sledge glides far more easily over firm desert sand simply because the sand does not pile up in front of the sledge as it does in the case of dry sand.
So there we go, no longer stuck between a rock and a hard place on that mystery.