They may have been "taught" that, but they were wrong.

I largely agree. But the history available largely demonstrates that this was the case. The myth that previous cultures thought the world was flat and were “proved wrong” by people like columbus was made up in the 19th century by the author of sleepy hollow. It is a uniquely american myth that many students today are also “taught”.

so it proves nothing.

The kicker is, it was never intended to!

People like eratosthenes and columbus had been taught from childhood that the world was spherical. They never once doubted it, and never sought to prove it right or wrong. Eratosthenes apocryphal procedure absolutely depends on the world being spherical (and many other unvalidated - and some plainly incorrect - assumptions to boot, like that all sunlight “rays” are parallel). His calculation is meaningless and nonsensical unless many unvalidated assumptions (taught to him from childhood as facts) are correct - including the one the calculation is erroneously purported to prove (that the world is spherical)! He never set out to prove anything, merely to estimate the circumference of the world by calculation already assuming it was (and dependent on it being) spherical.

They may have been "taught" that, but they were wrong.

I largely agree. But the history available largely demonstrates that this was the case. The myth that previous cultures thought the world was flat and were “proved wrong” by people like columbus was made up in the 19th century by the author of sleepy hollow. It is a uniquely american myth that many students today are also “taught”.

so it proves nothing.

The kicker is, it was never intended to!

People like eratosthenes and columbus had been taught from childhood that the world was spherical. They never once doubted it, and never sought to prove it right or wrong. Eratosthenes apocryphal procedure absolutely depends on the world being spherical (and many other unvalidated - and some plainly incorrect - assumptions to boot, like that all sunlight “rays” are parallel). His calculation is meaningless and nonsensical unless many unvalidated assumptions (taught to him from childhood as facts) are correct - including the one the calculation is erroneously purported to prove (that the world is spherical)! He never set out to prove anything, merely to estimate the circumference of the world by calculation already assuming (and dependent on) it was spherical.

They may have been "taught" that, but they were wrong.

I largely agree. But the history available largely demonstrates that this was the case. The myth that previous cultures thought the world was flat and were “proved wrong” by people like columbus was made up in the 19th century by the author of sleepy hollow. It is a uniquely american myth that many students today are also “taught”.

so it proves nothing.

The kicker is, it was never intended to!

People like eratosthenes and columbus had been taught from childhood that the world was spherical. They never once doubted it, and never sought to prove it right or wrong. Eratosthenes apocryphal procedure absolutely depends on the world being spherical (and many other unvalidated - and some plainly incorrect - assumptions to boot, like that all sunlight “rays” are parallel). His calculation is meaningless and nonsensical unless many unvalidated assumptions (taught to him from childhood as facts) are correct - including the one the calculation is erroneously purported to prove (that the world is spherical)! He never set out to prove anything, merely to estimate the circumference of the world by calculation.