as far back as the 6th century
At least 800 years before that, maybe more. Eratosthenes calculated Earth’s circumference around 240 BC. I would assume you have to believe the Earth is round is if you’re measuring a circumference.
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paddirn@lemmy.world 11 months ago
I thought even as far back as the 6th century people knew the world is round (Greeks/Romans), they even got the circumference pretty closely calculated. That wasn’t what was in question, it was what they would find that was in dispute. Columbus assumed he was taking a shortcut to get to India because he had some weird notions about the size of the earth (he thought it was smaller). The flat-earther stuff is more a modern conspiracy theory and Columbus’ story was embellished by Washington Irving (of Sleepy Hollow fame) to make it seem like everyone else thought the earth was flat.
teft@startrek.website 11 months ago
Jilanico@lemmy.world 11 months ago
You’re right, many (most?) ancient civilizations knew the earth is round.
It’s not a big mental leap. Things disappear over the horizon. The sun and moon are round. Maybe the earth is round too 🤔
marcos@lemmy.world 11 months ago
I always wondered where the crazy idea that people once believed that the Earth was flat came from.
So, looks like it comes from a single prolific academic that mixed fiction and history, describing people just about a century before him, and that everybody took for gospel. A famous book said “hey, everybody on your grandpa generation believed this”, and it became common knowledge!
I’m not sure I’m even surprised by something like this.
768@sh.itjust.works 11 months ago
sounds like a meme that aged like milk
NaibofTabr@infosec.pub 11 months ago
Yes, Eratosthenes estimated circumference of the Earth “with an error on the real value between −2.4% and +0.8%”, probably sometime between 250-200 BC (his adult life - I don’t think we know the exact date when he published his work).
Nougat@kbin.social 11 months ago
Absolutely right. Nobody really wanted to sponsor Columbus because they already knew how big the globe was, and that Columbus' proposed expedition would run out of supplies before he got to east Asia by going west - because they were unaware of the Americas existing.
The earliest globe that still exists was started in 1490, and finished in 1492, the very year that Columbus set sail. Columbus didn't return to Spain until March 15, 1493.
jmcs@discuss.tchncs.de 11 months ago
Exactly, the average educated estimate of that time was that Eurasia spanned 180º of longitude (which ended being surprisingly closer to the right value) and Columbus thought Asia was much bigger.