A mathematician from UNSW Sydney has unveiled an incredible discovery of an ancient clay tablet believed to be the oldest and most complete example of applied geometry. The clay tablet that holds the applied geometry notations is 3700 years old and has been hiding in plain sight in a museum in Istanbul for over a century.
The tablet is known as Si.427 and was discovered in the late 19th century in what is now central Iraq. While the tablet has been in the museum’s possession for a century, only recently has the significance been revealed. Si.427 is the oldest known example of applied geometry, and researchers say it was compiled by a Babylonian land surveyor.
Si.427 dates from the Old Babylonian (OB) period from 1900 to 1600 BCE. It’s the only known example of a cadastral document from the OB, a document used by surveyors to define land boundaries. The clay document shows legal and geometric details about a field that was split after some of the land was sold.
What’s significant about the object is that the surveyor used what’s now known as “Pythagorean triples” to make accurate right angles. Lead researcher Dr. Daniel Mansfield says that the discovery and analysis of the tablet have significant implications for the history of mathematics. The clay tablet was created over a thousand years before Pythagoras was born.
The surveyor who created the tablet precisely marked the boundary lines of the field using a simple example of Pythagorean triple, which has sides of three, four, and five to create a perfect right angle. The back of the tablet has cuneiform text, which is one of the earliest systems of writing. The text corresponds to the diagram on the front describing specifications, including the size of the field. On the bottom of the rear of the tablet are large numbers, which remain a mystery to researchers.