Australian scientists said that one of the most famous Babylonian clay tablets contains an analogue of the modern trigonometric table. Previously, the find was considered a school crib.
The tablet, known as Plimpton 322, was discovered in the early 20th century on the territory of modern Iraq. For more than a hundred years, her appointment remained a mystery. Scientists from the University of New South Wales said that they were able to identify the signs on the plate. According to scientists, it describes the ratio of the sides of right-angled triangles.
The tablet is dated from 1822 to 1762 BC. Earlier studies showed that it depicted numbers in four columns. It was assumed that the tablet served either as a “notebook” for the student, or as a “cheat sheet” for the teacher who checked the solutions of the equations.
The records use the sexagesimal number system that Babylon inherited from the Sumerians
The authors of the new work concluded that the table contains a list of Pythagore triples – sets of three natural numbers satisfying the equation a2 + b2 = c2. The most famous of these triples are numbers 3, 4 and 5. This ratio was used even before Pythagoras to draw right angles.
The left edge of the tablet is not preserved. Scientists suggest that initially it consisted of six columns of numbers and 38 lines. The table contains relatively large numbers: for example, the first remaining triple is formed by the numbers 119, 120, and 169.
According to the researchers, this list of numbers played the role of modern trigonometric tables. He made it possible to calculate unknown distances on the basis of available data – he could use it to carry out the boundaries of land plots and build large-scale structures. It is noteworthy that the author of the table did not use the notion of angle in calculations – instead he took into account the ratio of the lengths of the sides of the triangle.