Green
12.20.2018
Eratosthenes was a Greek scientist who lived from 276 to 194 B.C. He worked at the Alexandria library and did very WELL! HAHA! also the library burned 2 times. As well (again!) as doing the well stuff he also calculated the distance from the earth to sun, created prime numbers, and calculated the tilt of the earth (which he knew about at this time!). Eratosthenes also invented a system of latitude and longitude, and a calendar that had leap years.
Eratosthenes was a very smart man for his time. He calculated the size of the earth. It wasn't correct but very close to the real thing. The way he calculated the size of the earth was he saw in the newspaper that a well in Syana at one point of the day one this specific day direct sunlight shined down the well and you could see down the well. so he went over to his well and waited for that time and he couldn't see down the well. So he waited for next year so he could measure the angle of the sunlight which turned out to be 1/50 of a circle and calculated the distance from his well to Syanas and multiplied that by 50 to find the circumference of the earth!