For centuries, architects have marveled at the Ancient Egyptian pyramids and wondered how the Egyptians could have accomplished such feats without modern machinery. There are many questions surrounding the construction of these pyramids, but one of them has finally been answered- how did they move such large structures across the unstable surface of sand?

Researchers from the University of Amsterdam found something peculiar on a painting discovered in an Egyptian tomb. The painting depicts the usual line of laborers pulling a large statue mounted over a sled, but there is a man standing in front of the sled pouring liquid onto the ground in front of it. Up until now, Egyptologists believed that this was simply symbolic ritual; however, the scientists used this as an opportunity to develop an experiment.

The researchers built small-scale replicas of the sleds, placed very large weights over them, and put them in sand. When they pulled the sled on dry sand, the sand would pile up in front of the sled, and pulling would become much harder. Then they tried wetting the sand and found that the sled was much easier to move. Scientists explain that mixing water and sand creates a stable bond between the grains of sand, which is why building sand castles is much easier with wet sand.

This discovery can be used in construction even today, as it further advances the understanding of grainy materials like asphalt or coal and could lead to more efficient transportation for such materials. Even today we can learn from ancient civilizations.