Question about ancient cosmologies (flat earth with dome)

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Majin Gojira
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Question about ancient cosmologies (flat earth with dome)

Post by Majin Gojira »

In the ancient near east (and certain parts of the American South), the world was thought to be a flat disk with a clear dome over it separating the sky from the upper heavens.

Assuming that the dome is 10 miles high at its highest, how large would the sun/the moon be to appear that large?
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Re: Question about ancient cosmologies (flat earth with dome)

Post by NecronLord »

Are you sure that's the height you want? A ten mile high dome would be tremendously flat, given the distance from Jerusalem to the sides of europe, let alone America.
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Majin Gojira
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Re: Question about ancient cosmologies (flat earth with dome)

Post by Majin Gojira »

NecronLord wrote: 2017-08-07 12:35pm Are you sure that's the height you want? A ten mile high dome would be tremendously flat, given the distance from Jerusalem to the sides of europe, let alone America.
I am open to suggestions. Mostly, I'm trying to figure out the minimum size for the various solar/lunar eclipse swallowing monsters in various myths.

And with many other stories of various mountains "scratching the sky" or warriors who can climb tall mountains and 'stab the sky' as it were, I went with Everest's height and rounded up roughly. But, again, I'm open to ideas here.
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Re: Question about ancient cosmologies (flat earth with dome)

Post by Elheru Aran »

Of course the notion that people thought the world was flat is largely a myth, but that said, it's a fascinating enough concept on its own.

Generally Jerusalem was placed at the centre of the world (that darn Abrahamic religio-centrism), and I cannot speak for the Asian cosmologies... we can assume, I think, a rough diameter of Jerusalem to (approximately?) the edges of China or South Africa. Jerusalem to Cape Town is appriximately 10,000 KM; Jerusalem to Shanghai is ~8000. Call it about a 10K-KM radius, then.

That's far enough to reach the Americas; Baltimore, MD is only about 9450 KM. Rio de Janeiro would be right at the edge, 10300 KM and change, but you can imagine that a decent slice of Brazil would still fall within that diameter.

As for your question... well, a 10,000 KM high dome, that gives you your distance, and the rest is an angular diameter equation. The math defeats me at the moment because I don't have the time for it, but here... https://en.wikipedia.org/wiki/Angular_diameter
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Re: Question about ancient cosmologies (flat earth with dome)

Post by Majin Gojira »

Well, as an English major, it's absolutely beyond me. But oddly enough, 10,000KM is the given limit on NASA's website for the top of the Exosphere.

https://www.nasa.gov/mission_pages/sune ... yers2.html
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Re: Question about ancient cosmologies (flat earth with dome)

Post by Rhadamantus »

At 10 km height and 1000 km distance, the sun would be at .57 degrees elevation. At anything more than 2290 kilometers, the bottom part of the sun will be striking the ground. A sphere shape would work much better. A flat disk in the center. 10,000 km radius. At 1,000 km, the sun would be at 84.3 degrees. The tropics would go out to 4200 kilometers, the temperate zone to the edge.
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