In ancient Babylon, planetary motion was thought to reveal weather patterns and market fluctuations. In the service of astrology, Babylonian priests wrote
instructional texts on cuneiform tablets, many of which still survive. Almost all use arithmetic, but several make baffling references to trapezoids.
Mathieu Ossendrijver, a science historian at Humboldt University in Berlin, finally solved the mystery in a January Science paper. He found that the
Babylonians were thinking in surprisingly modern ways.
The insight came from a previously unstudied tablet that Ossendrijver spotted in a stack of old photos from the British Museum. The tablet makes explicit
mention of Jupiter, showing an arithmetical technique to predict the planet’s motion across the night sky as it appears to slow down. The numbers inscribed
in the clay — which calculate the total distance traveled by the planet — matched those on the perplexing geometric tablets.