Ya it’s a dry day on the interwebs so i’m throwing out some educational sh*t to broaden your knowledge and what not. It’s been debated for ages as to how the Egyptians managed to construct the great pyramids and in particular how they moved those giant boulders weighing several tonnes. Well new research may have come up with an obvious answer. The research was published last week in a physics journal and shows that wetting the sand in front of giant sleds made life much easier for the slaves to move massive pieces of rock.
A wall painting in an Egyptian tomb was previous thought to depict a purification ritual, but researchers now think it was just a dude throwing water on the sand to reduce friction. They did some science testing and found that wetting the sand actually reduced friction by as much as 50%.
The research paper is all technical stuff, but basically:
“the experiments revealed that the required pulling force decreased proportional to the stiffness of the sand. When water was added, capillary bridges arose; these small water droplets act like glue to bind the sand grains together. With the right amount of water, wet desert sand is about twice as stiff as dry sand, allowing the sled to glide far more easily.
“I was very surprised by the amount the pulling force could be reduced — by as much as 50 percent”
Now you know.
[via the appropriately named I f**king Love Science website]