Comment by dotancohen | Hacker News Reader

Comment by dotancohen | Hacker News Reader

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  > “This is a very specific and unique date,” Voulgaris said. “In one day, there occurred too many astronomical events for it to be coincidence. This date was a new moon, the new moon was at apogee, there was a solar eclipse, the Sun entered into the constellation Capricorn, it was the winter solstice.”

That's not a lot of coincidences, some of them are dependent. For instance, a solar eclipse can _only_ happen during a new moon. And the Sun enters a new constellation every month, the winter solstice defines the first day of a new month. The fact that a solar eclipse occurred exactly during the winter solstice is about 100:1 (there are at least two solar eclipses every year), and exactly the fact that a solar eclipse happened at a lunar inflection is about 15:1 (twice per month). So it's still a once in 500 year event, but not nearly as outstanding as the article makes it seem. Every day some once-in-500-year event or another occurs in astronomy.

> there are at least two solar eclipses every year

That's only if you consider them globally, as a solar eclipse (especially a partial one) covers only a small part of Earth. A single particular location e.g. Ancient Greece would see a full solar eclipse roughly every 360 years and some kind of partial eclipse roughly once a century, so that's quite a big difference, making a solar eclipse exactly during the winter solstice in Greece a very rare once in a 10000 year event.

Yes, and solar eclipses are the most noticeable astronomical event. Since the mechanism's precision is to the day, this makes it a 10,000 years * 365 days = 3,650,000:1 chance of being a coincidence.

> chance of being a coincidence.

You can’t really work it like that. If I roll a dice and get a 6, you’d maybe say that this might be a coincidence because there’s 6 possible outcomes, with 1 chance of a , so a high chance it was a coincidence. But there’s 365 days in a year, and 200 countries in the world. So actually the fact that I rolled a 6 on this day and in this country has a 1:73000 chance and clearly can’t be just a coincidence. Now clearly something must be up, and I must be cheating at dice!

Bad analogy. Fixed:

Once a day, you roll a dice with 3,650,000 sides. Only one of them shows a solar eclipse. On the day of the 200-year solar eclipse, the dice shows the solar eclipse side. Not a coincidence.

You're incorrectly applying a basic abstract statistical principle to a complicated real-world situation.

I think it would be less likely than 1-in-500, because even though there are multiple solar eclipses per year somewhere on earth, you would need to look at a the likelihood of a solar eclipse at a fairly specific part of the Mediterranean.

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