Friday, October 07, 2005
Blind Good Luck Day
Diomedes and I are going to the Columbus Day Parade tomorrow. We'll report back. Here's my take on Columbus Day, which I taught my children as soon as they learned about brave Columbus in Elementary School. You remember the story. Columbus figured out the Earth was round, while all around him thought it was flat, and so they mocked him when he set sail for the East by heading west and everyone thought he'd sail off the edge. And after about 4,000 miles sailing, he discovered Caribbean islands instead of the East and the discovery stuck and European colonization of the New World started.
Here's the truth:
Smart people have known the earth was a sphere for a long, long time. They even knew the real circumference of the earth since at least 200 BC when Eratosthenes of Cyrene measured it to at least within 2% and probably to within 200 miles (depending on the real measure of the 'stadion' he was using). His calculations survived and were commented on by Cleomedes and Strabo, and work along the same lines was known to the Muslim World in the 9th century AD through scholar Abu Ja'far Muhammad ibn Musa al-Khwarizmi, among others.
The World is about 24,800 miles around at the equator.
They also knew how far it was from Europe to China because they traveled the route since at least Marco Polo. It is about 8,600 miles from Madrid to Shanghai. So if one subtracts 8,600 from 24,800, the result is 16,200 miles. That's a long way by sea. By the last decade of the 1500s, sailing 16,000 sea miles was beyond the technological capability of the European sea going vessels or the endurance of their crews. They could barely make 4,000. No one thought to sail to the East by going west because it was just too far. All the sailors would die before reaching China. So no one tired.
Columbus calculated the circumference of the World and got it horribly wrong at only 12,000 miles. Oh, mighty navigator. 8,600 from 12,000 is 3,400 which was in range of the tiny little vessels the Europeans had. So off Columbus goes and had there not been two continents about 4,000 miles away from Spain, which no one in Europe (certainly including Columbus) knew about, he and his crew would have either had to turn around or all died on an endless sea.
It was blind good luck for Columbus that there were continents (and islands) just within sailing range of Spain at just about the place he mistakenly put China. Blind Good Luck.
Here's the truth:
Smart people have known the earth was a sphere for a long, long time. They even knew the real circumference of the earth since at least 200 BC when Eratosthenes of Cyrene measured it to at least within 2% and probably to within 200 miles (depending on the real measure of the 'stadion' he was using). His calculations survived and were commented on by Cleomedes and Strabo, and work along the same lines was known to the Muslim World in the 9th century AD through scholar Abu Ja'far Muhammad ibn Musa al-Khwarizmi, among others.
The World is about 24,800 miles around at the equator.
They also knew how far it was from Europe to China because they traveled the route since at least Marco Polo. It is about 8,600 miles from Madrid to Shanghai. So if one subtracts 8,600 from 24,800, the result is 16,200 miles. That's a long way by sea. By the last decade of the 1500s, sailing 16,000 sea miles was beyond the technological capability of the European sea going vessels or the endurance of their crews. They could barely make 4,000. No one thought to sail to the East by going west because it was just too far. All the sailors would die before reaching China. So no one tired.
Columbus calculated the circumference of the World and got it horribly wrong at only 12,000 miles. Oh, mighty navigator. 8,600 from 12,000 is 3,400 which was in range of the tiny little vessels the Europeans had. So off Columbus goes and had there not been two continents about 4,000 miles away from Spain, which no one in Europe (certainly including Columbus) knew about, he and his crew would have either had to turn around or all died on an endless sea.
It was blind good luck for Columbus that there were continents (and islands) just within sailing range of Spain at just about the place he mistakenly put China. Blind Good Luck.
# posted by Roger Fraley @ 5:48 PM 
