What is the oldest and most accurately known date in human history?
In 585 BC, the countries of Lydia and Medes were fighting in a war that had already lasted 15 years. On May 28, 585 BC, the final battle took place at the River Halys in central Turkey. (or Asia Minor as it was called).
What brought this war to a sudden, dramatic conclusion? The darkening of the skies was so intimidating that soldiers on both sides laid down their weapons and stopped fighting. In one brief moment, this eclipse brought this 15 year old war to an abrupt end!
And there was yet another important consequence of this eclipse: The Greek scientist / astronomer/ mathematician Thales, predicted there would be a total eclipse of the Sun on May 28, 585 BC
The legendary science writer, Isaac Azimov, has described the date of this battle as the oldest, most accurately known date (to an actual day) in human history and he called the eclipse prediction “the birth of science”.
First, it’s very unlikely that Thales accurately predicted a solar eclipse, since the required spherical-geometry models were unknown in his time. At best, he could have used knowledge of various luni-solar cycles (possibly directly influenced by Babylonian astronomy) to predict the possibility of a visible solar eclipse on a given date. But he had no geometric model for identifying the path of visibility of a solar eclipse, which is a much more localized phenomenon than a lunar eclipse.
“Asimov”. And given the known extent of observation and mathematical modeling of astronomical events in ancient Mesopotamia at least as far back as the second millennium BCE, calling Thales’ alleged prediction “the birth of science” is not a sustainable claim. It’s part of an outdated “Greek Miracle” historiography of science in which Hellenic/Hellenistic Greek philosophy is assumed to be the locus of ancient “science”, and observations and models of the natural world in older cultures such as Mesopotamia, Egypt and China are simply not counted.
In fact, Sir Fred (Hoyle) maintained that Stonehenge, which dates back at least a millennium earlier was an eclipse predictor. At least he claimed that he could predict eclipses using the alignments and there were several seeming “misalignments” that would actually make it much easier. The idea has not–putting it mildly–caught on.
I’m psychologically incapable of letting this low-hanging fruit pass by.
The earliest date in human history was Adam asking Eve to the Garden of Eden prom. It was a good news, bad news kind of event: There was no band, so they couldn’t dance, but there was also no chaperone so… woohoo!
I don’t see how the conclusion drawn in the OP and enshrined in the thread title follows from the premise. Why is it the oldest date in human history? Is there really no instance of “In this year, on the solstice…” or “In this year, five days after the equinox…”?
It seems a pretty tall claim that I struggle to accept without more than just the assertion itself.
This brings up the question of how sure we are of the oldest recorded years and what records were maintained to know that a year now expressed as 585BC was actually that year if it is not associated with an event like an eclipse. A recorded reference to an equinox in a particular year in whatever way it was expressed at the time would need a continuous set of records for each year up until a year that can be so verified.
Meh, start to work out some of those ancient Egyptian civil dates, e.g. when the heliacal rising of Sirius occurs on such-and-such a date, and you quickly find yourself in the 2nd or 3rd millennium (BCE)…
I grant that it’s not necessarily a given that a year can be known with precision, according to our present system of dating. No doubt the Bronze Age collapse and other calamities breaking the continuity in various ancient dating systems will complicate things. But before I can accept the assertion here that we can’t match a single event to a precise date prior to the 585 BC, I would at least expect some level of scholarly evaluation/explanation of why earlier candidates are necessarily excluded, given our present understanding of ancient history and the state of the historical record.
If you’re hip to the triple-Saros cycle, eclipses can be predicted with very high confidence, with or without any knowledge of orbital mechanics. If a fat partial or total solar eclipse occurred on a particular date at a particular spot, it’s a lead-pipe cinch that another fat-partial or total eclipse will occur over that same spot 669 new moons (54+ years) later.
However it seems unlikely that Thales knew about triple-Saros. No mention of it occurs in surviving Greek writing until the Hellenistic age, more than four centuries later.
Absent triple-Saros there are lesser periodicities and probabilities, but they are not as reliable and as Kimstu says if Thales used one of these he got lucky.
As for the date, I think the idea is that the battle is the event being dated, not the eclipse. There are records of eclipses in earlier cultures that from historical context can be assigned to a particular date, but no chronicler, to my knowledge, tied them to any non-astronomical historical event. If anyone knows of such an event and such a date I would be pleased to hear of it.