I'm re-reading The Rise and Fall of Alexandria. It's about the building of the City of Alexandria in Egypt a few hundred years before the birth of Christ. Alexander the Great conceived the idea, but the first stone had not been set when he died at the age of 32.
Ptolemy the 1st (pronounced Tolemy) realized the potential of Alexander's dream and was instrumental in building the city.
Not only was the city the center of commerce and culture, but was also a magnet for the best minds in those years. Mathematicians, scientists, astronomers, and philosophers.
The Library of Alexandria collected the books and works of the most brilliant people who'd roamed the earth.
I just finished the chapter where Eratosthenes measured the circumference of the earth using nothing but the reflection of the sun in a well at noon on the summer solstice, the length and angle of a shadow from a stick that was 600 miles away. Using this information and the belief that the earth was a sphere, he calculated within 180 miles the circumference of the earth.
History tells us the library burned and most of the irreplaceable work it contained was lost. Some of the most vital and valuable information ever understood went up in smoke while invaders celebrated. It's a humbling story to read.
I wonder where we would be as a people if we hadn't lost some of the keys to understanding.
Sometime in the future when I get full of myself and think I'm pretty clever, I hope I remember Eratosthenes.