|
Authored by: The Cornishman on Tuesday, May 15 2012 @ 04:27 PM EDT |
You'll be thinking of the measurements that Eratosthenes made of the Earth's
circumference; this wasn't meant to be a proof that the Earth wasn't flat; that
hadn't been seriously believed by the ancient Greeks for a very long time.
By knowing that on the summer solstice the sun shone directly down a well at
Syene at noon, while in Alexandria the sun was not overhead, all Eratosthenes
had to do was to measure the sun angle in Alexandria, and know the distance from
there to Syene to have enough information to measure the Earth. Luckily for him
his measurement and mathematical errors cancelled out, and his value for the
circumference of the globe was only about 100 miles out from our current
measurement.
Eratosthenes died at the end of the second century BCE.
---
(c) assigned to PJ
[ Reply to This | Parent | # ]
|
|
|
|
|