I’ve been watching — and totally digging — Carl Sagan’s ‘Cosmos’ all week. Eratosthenes was off the chain!
[good part starts at 1:45]
He was the first person to calculate the circumference of the earth by using a measuring system using stades, or the length of stadiums during that time period (with remarkable accuracy). He was the first to calculate the tilt of the Earth’s axis (also with remarkable accuracy). He may also have accurately calculated the distance from the earth to the sun and invented the leap day. He also created a map of the world based on the available geographical knowledge of the era.
What’s even more amazing is that after the remarkable discoveries of the Greek mathematicians, barely anything happened in the field of astronomy for 1600 years. Millions of people lived and died during a period where Ptolemy was the best information around.
I have no idea why it is that the west went through such an intellectual drought for so long. The other yellowed documentary I’ve been watching this week says it’s because the ancient civilizations were sacked by ‘barbarians’ who had no interest in science, math or literature. The did, after all, destroy the library at Alexandria.
As appealing as that narrative is, it seems a bit too easy, and doesn’t explain why the drought went on so long. I have no alternate explanation. I’m just glad to be living during one of the times when so much is being discovered.