Precisely Wet Sand Was Key to Building the Pyramids

A new study investigating granular materials may have unlocked the secret of one of the world’s greatest engineering mysteries.

sand, Innovation, Technology, Physics,egypt, pyramid

In the 21st century we’re pretty enamored with our ability to create amazing technology, and why shouldn’t we be? In the last few decades we’ve created wonders such as viable commercial spaceflight and smartphones that can video chat from anywhere. These technologies do not exist in isolation, though; they are born from a cascade of previous scientific work that’s equally as impressive – proving that engineering ingenuity has always been a common human trait.

In a recent study, University of Amsterdam scientists investigating the physics of granular materials stumbled upon a theory that may be instrumental in explaining how ancient Egyptians constructed the pyramids.

Inspired by a tomb painting that depicts laborers coaxing a sled forward as liquid was applied to the approaching sand, researchers began conducting experiments to determine whether liquid could help ease the motion of heavy objects over granular surfaces.

Using a miniaturized version of an ancient sled mechanism set upon a sandy bed, scientist began adding water to the sled’s foundation. As the liquid was added a capillary action began to draw the grains of sand together, stiffening the surface to such degree that the sled became much easier to pull. Through their experiment researchers found that there was an optimal amount of water that could be added to a set volume of sand, beyond which a sled would require more force to move.

According to the FOM press release, “Besides revealing something about the ancient Egyptians, the [study has] modern-day applications. We still do not fully understand the behavior of granular material like sand … asphalt, concrete and coal. The research results could therefore be useful for examining how to optimize the transport and processing of granular material, which at present accounts for about ten percent of the worldwide energy consumption.”

Inventor and writer Arthur C. Clarke once mused, “Any sufficiently advanced technology is indistinguishable from magic.” While the great pyramids and many of ancient Egypt’s most amazing monuments weren’t built using magic, the shear feats of their construction still confound us. More importantly though, their construction methods still offer us insight into how fundamental physics and technology work – which is a certain kind of magic to me.

Image Courtesy of FOM