On this date (well sort of who knows exactly what calendar they were using) a solar eclipse occurred, as predicted by the Greek philosopher Thales, while Alyattes was battling Cyaxares leading to a truce. This is the earliest event of which the precise date is known.
How could ancients predict solar eclipses. I realize they come with some regularity and the regularity of lunar eclipses which can be seen by half the Earth could likely be predicted. But how regular would solar eclipses that the Greeks would know about have occurred. And the timing has to be quite accurate to know where on Earth it would be seen.
This intricate device, discovered in a shipwreck, was an analog computer with gears and dials that allowed for the simulation of celestial bodies’ movements, including the Moon and Sun. It could predict eclipses by tracking the Saros cycle.
The Antikythera mechanism is dated to sometime between about 200 BC and 100 BC. Thales died around 550 BC. He certainly did not use the Antikythera mechanism. Probably nothing like it existed in his time. But the mechanism was designed based on an understanding of various astronomical cycles, and perhaps some of that theory was developed by Thales hundreds of years earlier.
The claim that Thales predicted an eclipse which later took place and interrupted a battle between the Median king Cyaxares and the Lydian king Alyattes comes from Herodotus. However, this claim is suspect for several reasons, the most obvious being that Herodotus himself says that Cyaxares died ten years before the date of the eclipse. I believe many, if not most, modern historians do not accept that Thales predicted this particular eclipse, and many believe that he probably did not predict eclipses at all.
You don’t need something as complicated as an Antikythera Mechanism to predict eclipses. As Gerald Hawkins pointed out in 1966 in Decoding Stonehenge, you can simply use the Aubrey Holes at Stonehenge and a couple of markers to calculate when eclipses will occur. Astronomer Fred Hoyle rebutted a critic of the idea and gave detailed instructions on how to do it.
I suppose that with all these stories about ancient predictions of astronomical events, there could be a fair amount of ex post validation at work. Suppose Thales predicted that an eclipse would occur on 28 May 585 BC. But the Greeks used an entirely different calendar. How do we know, then, that the date Thales wrote about was the day we’d designate as 28 May 585 BC in our calendar? The only reason we know that is that we can calculate that a solar eclipse took place on that day, and it’s the only one that matches the description in terms of place, visual effect, and Thales’ approximate birth and death dates. But this is circular reasoning: We’re assuming that Thales correctly predcited the eclipse of that day in order to determine the day he predicted the eclipse for. As soon as you’re doubting the accuracy of the written event, the entire story breaks down.
That’s equivalent of saying that you can’t make a stopwatch without knowing the speed of sound. Just because a suitably knowledgeable person can use a stopwatch to calculate the distance to a lightning strike.
Certainly if the 56 holes were dug to mark 3 18.61 (Actually 55.83) years on the lunar eclipse cycle, then they must have known of the cycle before they decided how many holes to dig.
In any case, most thinking these days is they were not used to mark lunar eclipses. They never would have been used to mark solar eclipses, which don’t repeat at a given location in anything like 18 years.
What you you mean “but”? I didn’t say that they used Stonehenge to figure out how to predict eclipses. I was pointing out that you didn’t need a complex geared mechanism to do the predicting. In either case, you constructed your calculating device already knowing how to do the calculation.
Yes, it is real, but of course the one in the film was the fantasy version. Just like no doubt Jesus drank wine at the last Supper, and thus there was a chalice or cup, vs a grail that can cure all wounds and make you live forever.
We also don’t know how many times he incorrectly predicted an eclipse. Nobody would bother writing that down. “That Thales guy - always with the eclipses…”
