How did thales of milete predict upcoming eclipses?
There is a cycle known as the Saros, which is the recurrence of similar eclipses after a period of 18 years and 10 or 11 days. If an eclipse occurs, it’s possible to say. with a fair degree of certainty, that another will take place after this period, although the area of visibility moves westwards, so successive eclipses are not generally visible from the same location. The eclipse which Thales predicted is thought to be that of 28th May 585 BCE. The eclipse preceding that date by one Saros period was the eclipse of 18th May 603 BCE. Both these eclipses were visible from Thales’ location in the eastern Mediterranean.
