It remains to speak of the philosophers themselves,
and in the first place of Thales.
~ Diogenes Laërtius, Lives and Opinions of Eminent Philosophers
According to Herodotus, it happened amid a battle between the Lydians and the Medes. For five years the two had been in conflict, waging a war in Anatolia in which neither could gain an upper hand. Nor would this battle make a difference: they were, Herodotus tells us, fighting with equal success.
But then came a moment of terror: the Sun vanished, day turned to night, and the battle abruptly ended. The eclipse must have lasted for no more than a few minutes, but the message was clear. The gods were angry, and peace must be had. To ensure their will was carried out, the two sides recruited the king of Babylon, Nebuchadnezzar, as a mediator. Lasting peace, Herodotus said, was then guaranteed by a royal marriage between the two enemies.
But he also told us something else about this battle. A man named Thales, Herodotus wrote, had warned the Ionians the eclipse was coming, and even given them the year in which it would arrive. When it came as he foretold the people were astonished, and Thales became a man of legend.
Herodotus did not record the year in which this happened. But he did give us some clues. We know it happened in the reign of a king called Alyattes, who ruled around the year 600 BC. And we know it occurred in Anatolia, in the west of what we now call Turkey. And we can assume, from its impact, that the eclipse was either total or close to it.
Calculations of past eclipses do show a possible match: one really did take place on the evening of May 28, 585 BC1. That suggests there is some truth in the tale of Herodotus, who was, it must be said, sometimes regarded as an unreliable historian. But even if the story of the eclipse is true, the question of how Thales could have predicted it is baffling.
Possibly, some have argued, Thales spotted a pattern in how eclipses appear and then used that to guess one would occur around 585 BC. That’s not impossible – eclipses do follow a repeating pattern, and patterns in the lunar eclipses were already known by 600 BC to the Babylonians.
But solar eclipses are rarer than lunar ones, and even if Thales somehow had access to Babylonian records, it seems unlikely he could have worked out the pattern with any accuracy. Maybe he just made a lucky guess, and was feted when it turned out to be right. Or maybe Herodotus made up the story, perhaps out of desire to embellish his writings and to praise the man the Greeks seem to have regarded as the father of philosophy.
Whatever it was, few today seriously believe Thales could have predicted the eclipse of 585 BC.
Thales, The Man
Traditionally the story of science begins with Greek philosophy. And the Greeks, for their part, thought philosophy began with Thales.
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