This is Eratosthenes. He was a librarian. Well, to be precise, he was the Head Librarian for the Library of Alexandria, one of the most famous libraries in history. That’s not generally what he’s remembered for, though (when he’s remembered at all…)
Born in 276BC, Eratosthenes was something of a polymath. He studied Stoicism under its founder, Zeno of Citium, then became a student of Ariston, who was a Cynic. He also spent time in the Platonic Academy, under Arcesilaus. He wrote poetry and historical works, and he performed some incredible mathematic calculations, most notably the circumference and axial tilt of the Earth.
How did he discover these things? Well, the explanation of the calculation of the circumference is the more relevant for today, and I can barely understand it myself. Essentially, he knew that the sun would be directly above the Egyptian city of Swenet (now Aswan) at noon on the Summer Solstice. He measured the sun’s elevation in Alexandria on the same day at the same time and found it to be 1/50th of a circle (7°12′) south of the zenith. Knowing the distance between the two physical locations, he could calculate the arc (the curved portion of the Earth’s surface), and assuming that the Earth was a sphere, he knew what percentage of the circumference was represented by that distance. The rest is a matter of either multiplication or division, depending on your choice.
Why does this matter? Because it happened 200 years before our new calendar started, a calendar that is now at 2016 years. And we have this bozo:
My last-but-one play came back from my publisher this week with a few pertinent notes on it. One of them was pulling me up for a character saying “People used to believe that the Earth was flat”. My publisher pointed out that the impression given was that it was the majority view for thousands of years before being disproved relatively recently – say during the Renaissance. But Eratosthenes knew enough to perform his experiment while there was still a library in Alexandria, and today we have people mooching about who seem determined to burn that library all over again.
Should we question established wisdom? Certainly. But we are the latest in a long line of thinking people. The information is there, preserved in the libraries of centuries, and now more available than ever before. B.o.B. saw something that didn’t match up with what he had learned in school, but he didn’t go and look for the answers. He Tweeted a petulant question, and when people lined up to educate him, he doubled down on his ignorant stance, preferring to believe that he was a rebel against misinformation, a voice in the wilderness, instead of simply wrong.
Which reminded me of this: