Yes, it's from a book called "Uncle John's Bathroom Reader" and that book was resting on a closed toilet seat in a nation that only kind of uses the metric system in certain situations... however, you'd be surprised how much you can learn after a single visit to any local fast-food joint!

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[–] 8 points 1 day ago (7 children)

So how the hell was it done? Long piece of rope? Hot air balloon? Or having a bird fly from one point to another and timing it?

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  • [–] 25 points 1 day ago (5 children)

    Calculations. In 240 BCE, Eratosthenes used a stick. He basically found a place where the sun was directly overhead, and measured the shadow from a stick a known distance to the north of that location. He approximated the circumference of the earth to be 25,000 miles, which was off by 99 miles.

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  • [–] 3 points 1 day ago (1 child)

    How do we know the conversion of whatever length unit he was using, in modern units?

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