The Great Sphinx of Giza may have been shaped by desert winds long before humans laid hands on it.
“This discovery came as a complete surprise,” says geomorphologist Elena Favaro from the Open University in Milton Keynes, England, who was not involved in the study. Scientists are uncertain about the exact process of yardang formation, but they are found in desert regions where winds erode exposed rock into long, streamlined ridges facing the prevailing winds. Favaro describes the study as “a very innovative approach” to understanding how yardangs are formed.
Intrigued by how nature creates sphinx-like yardangs, Leif Ristroph, an applied mathematician from New York University, decided to investigate the question in his laboratory. Ristroph and his team study the growth and transformation of natural shapes by simulating years of erosion in experiments that last a few hours. They conduct these experiments in a water tunnel typically used to study fluid flow around solid objects like wings.
“What we do, which is somewhat unconventional,” Ristroph explains, “is place objects like a piece of ice in the tunnel and observe how their shape changes” — or, in this case, a chunk of mud.
2023-11-29 11:00:00
Original from www.sciencenews.org
