The lies they told us in school

I don't remember much about my kindergarten experience, except that it wasn't really my thing. I never did like to draw, color, sing, or do any other fun stuff like that, and the parents always put me in morning kindergarten (back when it was only a half day), so I was never awake. Maybe another reason I didn't like it, but didn't realize it at the time, was the lie that was perpetrated for generations before me that Columbus sailing to the New World proved the Earth was round.

I still don't see any great reason to celebrate Columbus Day (except for the day off school of course; I'll never turn one of those down). He missed his target by 12,000 miles (not to mention a whole ocean), never actually landed on the mainland of either continent of the Americas, enslaved the natives, and due to his navigational prowess gave them a name that lasted for centuries: Indians. One thing he did not do, however, was prove the Earth wasn't flat.

Granted I don't know the opinion of the common person, but it was a well-known fact among the scientific community that the world was nowhere near flat. A few indicators: when a ship sailed over the horizon, the hull disappeared before the sail. During an eclipse, the shadow of the Earth on the moon was clearly round. The north star Polaris is close to the horizon at the equator. Shadows don't all point in the same direction.

The shadows thingy mentioned above was actually used to calculated the circumference of the Earth by Eratosthenes some 200 years before the birth of Christ, and he got it pretty close (within 5%-15% depending on which definition of the stadion you go by). This measurement came several hundred years after Pythagoras and Plato had decided the Earth was round, although they didn't have any evidence besides their own reasoning).

I've asked around a bit, and most of my American students weren't taught that Columbus disproved the flat Earth. That means that somewhere in the ten years between my kindergarten experience and theirs, someone seems to have gotten their heads together and started teaching the truth, or at least not telling outright lies.