There was also that test where the sun created a longer shadow on one obelisk in Egypt compared to one not even that far away, both the same height and width. By calculating the length of the shadows and how far apart the obelisks were they were able to calculate the curvature of the Earth to near perfection. Simple tests like this can even be done today on one's own to prove the Earth is a globe.
Exactly. There must be a very specific degree of curvature to create such effects. When you calculate the degree, you find out that it must curve so much as to curve all the way around back to itself again, meaning a globe shape.
There was also that test where the sun created a longer shadow on one obelisk in Egypt compared to one not even that far away, both the same height and width. By calculating the length of the shadows and how far apart the obelisks were they were able to calculate the curvature of the Earth to near perfection. Simple tests like this can even be done today on one's own to prove the Earth is a globe.
You can see it on the Suez Canal. The telegraph poles along the canal get decreasingly smaller the further away they are.
And there is this: https://files.catbox.moe/bth04g.png
Exactly. There must be a very specific degree of curvature to create such effects. When you calculate the degree, you find out that it must curve so much as to curve all the way around back to itself again, meaning a globe shape.
IIRC that was Eratosthenes, you two anons are on the same page