Do you know that an Ancient Greek mathematician calculated the Earth’s circumference without ever leaving home?
Eratosthenes (276 BC to 194 BC) was a Greek mathematician, geographer, poet, astronomer, and music theorist who is best known for being the first person to calculate the circumference of the Earth.
Thanks to technology today, we can easily find out the circumference of our planet by simply “Googling” it online. But this man in Ancient Greece came up with nearly the exact same figure without using any modern equipment. More than 2000 years ago, Eratosthenes only uses a stick and his brain to calculate it long before NASA was able to send satellites up into space to determine the exact circumference of the Earth.
However, there are some who argue that the Earth is in fact not a sphere, but a flat plane, they are known as the Flat Earth Society.
Based on a report, Eratosthenes, way ahead of his time, discovered that no vertical shadow is a cast at noon on the summer solstice at the Egyptian city of Syene (now Aswan). The explanation about this is because the Sun was directly overhead.
The Greek mathematician tried to prove if the same thing happened when he returned to his city in Alexandria. He then planted a stick in the ground to see if a shadow would be cast at noon. It turns out that there was a shadow, and it measured around seven degrees.
He confirmed the speculation that the Earth is round using this simple and extremely low budget technique. Because If it was not curved or round, Eratosthenes should not have seen any shadows in Alexandria, as it also happened during his visit to Syene.
Around 500 BC, the concept of a “spherical Earth” was theorized by Greek philosopher Pythagoras and after a couple of centuries, it was validated by the great philosopher Aristotle.
Eratosthenes, who is also the head of the library in Alexandria could use his observations to measure the planet’s circumference if the Earth was a sphere.
This Greek Mathematician must not be so popular for the Flat Earth Society.