An interesting solution: how the ancient Egyptians moved massive stone blocks for the pyramids

For many years there is a literary and journalistic cliche of the "secrets of the Egyptian pyramids". The main mystery for scientists was the construction technology. Everyone knows that the nearest sources of building material are at a considerable distance from the pyramid construction site. The blocks from which the tombs of the pharaohs are erected are of impressive size. How did the ancient builders, without having powerful vehicles at their disposal, manage to deliver such heavy objects? It seems that physicists from the University of Amsterdam were able to shed light on this mystery, which has been worrying for centuries.

Mystery of the ancient wall picture

The key to unraveling was the ancient Egyptians themselves. On one of the frescoes preserved on the inner wall of the room in the tomb of the pharaoh Jehutihotel, dating back to around 1900 BC, the researchers discovered a very interesting image. Rather, it would be argued that this element of wall painting was known for a long time, but scientists from the Netherlands just looked at it in a new perspective. What did they see?

The mural depicts 172 men moving a huge statue with ropes attached to runners. On the front of this sledge is another man and pours water on the sand. Earlier Egyptian scientists believed that this action was of some kind of ritual character. But the professor of physics Daniel Bonn put forward the hypothesis that the purpose of wetting sand is utilitarian. He understood more than history specialists. That's what a fresh look means.

It's all in the wet sand!

Bonn and his colleagues built a miniature sleigh, and then began experimenting with drawing heavy objects along a layer of sand. The addition of water increased the boundary strength of the bulk material, and the friction force decreased. The discovery of this practical phenomenon required a theoretical justification, and it was done. Droplets of water create tiny "bridges" between the grains of sand, holding them together. For the same reason, beach castles and sculptures are created from wet material, and dry immediately disintegrates.

Optimal humidity

It would seem that the solution is simple, and it's enough to water the sand with sand to move any heavy objects on it much easier. In fact, as in any other case, you can overdo it. Friction when using dry sand is large, but also on wet-drawn building blocks is also very difficult. The optimum effect is achieved with a humidity of 2-5% of the volume. In this case, labor costs are reduced by half, which, apparently, was used by the builders of the Egyptian pyramids.

The obtained results have not only historical but also quite practical significance. They will help to understand the behavior of other bulk materials, such as asphalt, concrete or coal, which will lead to the development of more efficient ways of transporting these resources.