By that I mean, if you would imagine these sticks extending all the way down to the center of the Earth they would there intersect at an angle of about seven degrees.' For the observed difference in the shadow lengths, the distance between Alexandria and Syene had to be about seven degrees along the surface of the Earth. Sticks at different angels to the sun's rays will cast shadows at different lengths. He continued: 'The sun is so far away that its rays are parallel when they hits the Earth. Moon Landing Was a Hoax, Half of Russians Believe Not only that, but the greater the curvature, the bigger the difference in the lengths of the shadows,' Sagan said. But how could it be, Eratosthenes asked, that at the same instant there was no shadow at Syene and a very substantial shadow at Alexandria? The only answer was that the surface of the earth is curved. If the shadow at Syene is a certain length and the shadow at Alexandria is the same length, that also makes sense on a flat earth. Now if at a certain moment, each stick casts no shadow-no shadow at all-that's perfectly easy to understand provided the earth is flat. One up here in Alexandria and one down here in Syene. He explained on a 1980 episode of his popular TV series Cosmos and used a cardboard map to elaborate on the experiment Eratosthenes first conducted before he set out to determine the circumference of the Earth all those moons ago. Well, according to an experiment conducted by astronomer, cosmologist and astrophysicist Carl Sagan, the idea of the Earth being in the shape of a circle can be easily proven just by merely tracking shadows. If the Earth looks flat while walking on it, and it feels flat, then it must be flat, right?

The conversation is buzzing with people on Reddit forums like r/flathearth and on Twitter who makes claims that satellite photos of Earths and other facts that have proven Earth's roundness are part of a round Earth conspiracy comprised by the government. iStock / Getty Images PlusĪnd yet, the argument that the Earth is flat is one still made by many people, all these thousands of years later. Background of the planet earth viwed from satellite, this image is generated with 3D software and Elements of this image are provided by NASA.

Is earth flat or round