Astronomy from Babylon

Prof. Teije de Jong
'Anton Pannekoek' Instituut, Amsterdam

The ancient city of Babylon, situated at the banks of the river Euphrates in present-day Iraq, may be considered as the cradle of astronomy. Already during the 2nd millennium BC the Babylonian priesthood carefully observed the sky from night to night to read the will of the Gods from heaven and to advise king and country accordingly. A surprisingly large amount of information about Babylonian culture has survived and is available in cuneiform script on clay tablets dug up from the Iraqi desert. At present over one half million clay tablets and fragments are kept in different musea all over the world. Several thousands of these contain astronomical texts.

The Babylonian scholars were not only careful observers of the stars and planets, but from about 500BC onwards they developed theoretical arithmetical schemes which enabled them to compute and predict the positions of the sun, moon and planets with an accuracy comparable to that of the later Greek theories of Hipparchus and Ptolemy. The Babylonians had a talent for computing. They introduced the place-value notation and the sexagesimal system. Several basic astronomical concepts were first developed by Babylonian astronomers.