Did Babylonian scribes know Pythagoras's theorem 1,000 years early?

A partly broken clay tablet sits in the collection of Columbia University. It was made around 1800 BC in Babylonian cuneiform, and it carries a table of numbers. Each row relates to a Pythagorean triple: three whole numbers where the squares of the two shorter ones add up to the square of the longest. So the answer to the question is yes, in a way. Scribes in Mesopotamia used the rule roughly 13 to 15 centuries before the major Greek discoveries in geometry.

Some of the triples are huge. Row 4 relates to (12709, 13500, 18541), far too big to find by trial and error, so the author seems to have had a systematic method. The tablet was bought around 1922 by the New York publisher George Arthur Plimpton from a dealer, and left to Columbia in the 1930s. In the 1940s Otto Neugebauer and Abraham Sachs realised what it meant.

But what was it for? Nobody knows. Neugebauer and Sachs saw a study of whole-number solutions, almost a Babylonian number theorist at play. Another reading says the first column is a table of squared secants or tangents, with the rows sorted by angle in steps of about one degree. That sounds like a trigonometry table from nearly 4,000 years ago.

The twist is that the Babylonians are believed not to have used the concept of measured angle. The scholar Robson argues the tablet came from a list of regular reciprocal pairs, and that the trigonometry reading is anachronistic. She points out that it was written in the format of administrative documents, not mathematical ones, and an award citation for her work said the author was more likely a teacher and the tablet a set of exercises.