**Jaw droPping Greek ancient diSCOVERIES**

Did you know ancient Greeks knew the Earth and Moon sizes? Not only that, but they also knew that the planets orbit around the sun (Heliocentric theory) and even had a complicated astronomical calculator. With that in mind, how many of us can even identify Venus or Orion’s belt at night, right?

What does this have to do with energy? Maybe Mars is the next frontier and our next source of materials, but in the meantime, we’re stuck here on Earth. Or just like Jesse used to say: Science, bitch!

Most of the astronomy has to do with Math but also with observation. Later, as I did an extra course diploma for Math, I had a great professor who showed us how ordinary people could measure Earth’s circumference. About the size of the Moon , we will need more telescopic observation, but it’s doable.

**How did they do it? How do you measure something so big? **

Earth circumference:

Eratosthenes (276BC to 195 B.C.) chief librarian at the Great Library of Alexandria, came up with a smart way of estimating Earth’s circumference. Greeks (Pythagoras) already knew by 500 B.C. that Earth was round, but not how big. Ancient Greeks considered spherical shapes as the most perfect shape. Aristotle (384-322 B.C.) can help you demonstrate your flat-earth “friends” (and even ourselves) that earth is round. This can be demonstrated as ships disappear hull first when they sail over the horizon, Earth casts a circular shadow on the Moon during a lunar eclipse, and different constellations are visible at different latitudes.

Back to the Eratosthenes method, he measured different lengths of shadows casted by poles stuck vertically into the ground, at midday on the summer solstice, at different latitudes. For this he was assisted by a person to measure distances (very usual back then). So the difference in the shadows demonstrated how much the Earth’s surface curved. Eratosthenes used this to estimate the Earth’s circumference as approximately 40,000 km (25,000 miles). This is within a couple of percent of the actual value, as established by modern geodesy (the science of the Earth’s shape). To see the video, click here.

As a summary, Greek philosophers thought that maybe what happened on Earth was not a product of the Gods but by natural phenomena that could be explained.

If you want to know more about the calculator, the size of the Moon, and the planets orbiting the sun, you can read the full article here.

As always, share your thoughts and keep the conversation going. As a token of my affection to promote future chatting, have some chatting kitties.

#greeks #earthcircumference #erasthostenes