A photo from open sources
Historians have suggested that the ancient Egyptians during the construction of the pyramids may have moved massive stone blocks through the desert by wetting the sand that was pulled blocks. Physicists from the University of Amsterdam found that if pre-wet sand to be moved massive object, this greatly reduces friction and simplifies task. These findings help answer one of the most mysterious. questions of history: how the Egyptians were able to fulfill seemingly the impossible task of building the famous pyramids. Exploring wall painting in an ancient burial site dating from 1900 to AD, scientists discovered images of 172 men pulling huge statue with a rope attached to a special sleigh. In this image you can clearly see how a man standing on front of the sled, watering the sand with water. Egyptologists thought that it was a purely solemn act of ritual. However, scientists decided to experiment. They built a miniature sled and held out heavy objects through trays of sand. When the researchers dragged the sled on dry sand, they concluded that this activity is pretty laborious. When the experiment was repeated with wet sand, the sled was more quickly and easily began to slide on the surface. It turns out water droplets create bridges between the grains of sand that help them stick together, scientists say. For the same reason, build a wet sand castle is much easier than a dry sand castle. However here it’s important to consider the balance, because too wet sand is also bad as well as completely dry. The amount of water added depends on the type sand. As a rule, the optimal amount of water is between 2 and 5 percent of the volume of sand. It turns out that the wet sand of the desert reduces friction, which means that for the same work less power is needed.