Andrew Kelly/Rare Books and Manuscripts Library at Columbia University: The Plimpton 322 tablet Andrew KellyAncient Babylonians knew key concepts of geometry, including how make right-angled triangles. This mathematical knowledge was used to divide the farmland over 1000 years before Pythagoras, the Greek philosopher with whom these ideas are closely associated.According to Daniel Mansfield, a Sydney-based researcher at the University of New South Wales, they are using theoretical knowledge of objects to perform practical tasks. These objects were almost 4000 years old, which is quite strange.Babylonia was one among several ancient Mesopotamia societies that overlapped. It was located in southwest Asia between the Euphrates and Tigris rivers. Babylonia was a city that existed between 2500 BC and 500 BC. The First Babylonian Empire ruled a large region between 1900 BC and 1600 BC.AdvertisementMansfield is currently studying Plimpton 322, a fragment of broken clay tablet dating from that period. It has cuneiform markings on its surface that form a mathematical table listing Pythagorean Triples. Each triple is the length of each of the sides of a right-angled triangular triangle. Each side is a whole number. The simplest example of this is (3, 4, 5,); others include (5. 12, 13, and (8. 15, 17).Pythagorass Theorem states that the lengths of triangles sides correspond to their squares. This is because the square of the longest side equals the sum of squares on the two other sides. This famous bit of mathematics is named after Pythagoras the Greek philosopher. He lived between 570 and 495 BC, long before the Plimpton 322 tablet was created.Mansfield says that they [the early Babylonians] were familiar with Pythagoras' theorem. Why?Mansfield believes he has the answer. The key clue was a Si.427 clay tablet that was found in Iraq in 1894. Mansfield traced it to the Istanbul Archaeology Museums.Si.427 was a surveyor's tablet that could be used to calculate the proportions of land parcels by dividing them into rectangles. Mansfield says that the rectangles are often a little wonky as they are only approximate. Si.427 is a different. He says that the rectangles are perfect. This was possible by using Pythagorean Triples.Mansfield says that even the shapes of these tablets tell stories. Si.427 can be described as a hand tablet. Someones took a piece of clay and put it in their hands while surveying fields. Plimpton 322, on the other hand, seems more academic. It is an investigation of Pythagorean Triples that was perhaps inspired by the problems surveyors faced. He says that someone took a large slab of clay and flattened it while sitting at a computer.Journal reference: Foundations of Science, DOI: 10.1007/s10699-021-09806-0Subscribe to Our Human Story, a monthly newsletter about the revolution in archaeology & human evolution
