In 1906, the tomb of the ancient Egyptian architect Kha was discovered intact near the Valley of the Kings. The tomb yielded several objects that would have been used by the architect, including cubit rods and a leveling device that resembles a modern set square. But the tomb also contained a mystery: An oddly shaped, hollow wooden object with a hinged lid baffled archaeologists as to its function.
For over 100 years, the strange object was labelled as a case that had probably once held another leveling instrument or a balancing scale. But now an Italian physicist has suggested that it is not really a case at all. Instead, she believes it is the world’s first example of a protractor.
Amelia Sparavigna is a physicist at Turin Polytechnic. Based on numbers encoded in the carvings on the Egyptian object’s surface, Sparavigna believes it could have been used to determine the incline of certain angles. The numbers resemble a compass rose, with 16 evenly spaced petals surrounded by a circular zigzag shape with 36 corners. When the straight side of the object is laid on an angle, Sparavigna believes that a plumb line would show its inclination on the circular dial.
What we know about the Egyptians adds some creedence to Sparavigna’s theory. The fraction one-sixteenth is used in a calculus system the Egyptians had knowledge of. The Egyptians also recognized 36 star groups called the decans, which were later used to form the basis of a star clock. From this, Sparavigna believed the object was a protractor that had two scales, one based on Egyptian fractions, and the other based on decans.
However, where Egyptian history provides some support for Sparavigna, it also provides a critique. Kate Spence, a specialist in Egyptian architecture at the University of Cambridge believes the object is nothing more than a decorative case. One of the most fascinating aspects about the Egyptians was how mathematically precise they were in their construction. Measuring instruments used by the Egyptians have a precedent of being tremendously accurate. The object from Kha’s tomb? Not so much. According to Spence the number carvings aren’t nearly as accurate as they would be on typical Egyptian tools.
We may never know exactly what the strange object was used for, but regardless of whether or not the Egyptians invented the first protractor, there is still no doubt they rocked at math, and the object still serves as a testament to Kha and the ingenuity of ancient Egypt’s architects.
(via New Scientist)
