14 DAY TRIAL // One of the world's greatest mysteries is how it was that ancient Egyptians managed to drag the stones they used to build their pyramids across the desert.
Given the limited technology available at that time, there is little denying that, once aliens are out of the picture, not all that many explanations are left.
The good news for those who cannot sleep at night for fear that they might never learn how the pyramids were built is that a team of scientists with the University of Amsterdam in The Netherlands claims to have solved this mystery. Live Science informs that, in a new paper, these physicists explain that, after researching the forces required to drag heavy objects across the desert, they found that the secret to making sure such endeavors end in success lay in the dampness of sand.
Specifically, the researchers say that, according to evidence at hand, pouring some water over sand reduces friction, thus making it easier to pull heavy objects with the help of a sled across the otherwise tricky terrain.
To prove that their theory was not pure mumbo-jumbo, the physicists even took the time to put it to the test. They pieced together several miniature sleds similar to the ones believed to have been used by ancient Egyptians and then attempted to drag them over dry and over wet sand.
It was thus discovered that, when the sleds were being dragged across dry sand, more force was needed to pull them than when the sleds were carried over wet sand, the scientists detail in their paper in the journal Physical Review Letters.
“It turns out that wetting Egyptian desert sand can reduce the friction by quite a bit, which implies you need only half of the people to pull a sledge on wet sand, compared to dry sand,” researcher Daniel Bonn said.
“If you use dry sand, it won't work as well, but if the sand is too wet, it won't work either. There's an optimum stiffness,” the University of Amsterdam specialist further detailed his and his colleagues' findings.
The theory that ancient Egyptians used sleds and wet desert sand to carry the huge blocks of stones that they used to build their pyramids across the desert is backed up by a wall painting found in a tomb dating back to 1900 BC.
This painting shows several dozen men transporting a statue using ropes attached to a sled while another man is walking in front of them and pouring water over the sand.