In ancient mythology various gods controlled the oceans In Greek mythology Poseidon was king of all the sea gods The king of the Roman seas was called Neptune Sumerian myths proclaimed that Amathaunta was the goddess of the oceans The sky became the heavens holding power over their very existence The oceans and tides were also powerful forces that commanded their respect The ancient Greeks worshipped Gaea their word for Mother Earth They believed that she created the universe The ancient peoples told many stories or myths describing these and other supernatural beings and their activities It was their way to explain what was going on in the world around them 6
While most people tried to define the unknown as divine beings that ruled over their lives there were early scientists who wondered about these mysteries in other ways The earliest recorded scientists who tried to understand the mystery of the heavens were the Babylonians in 1600 BCE They studied the positions and movements of planets the moon and the stars recording their findings In the beginning these scientists suggested that the Earth was flat or cylindrical and surrounded by a cosmos Shaping Our Understanding Despite scientific evidence that Earth was a sphere by about 300 CE some early Christians decided this notion was a pagan absurdity It wasn’t until about a thousand years later that pretty much everyone was convinced that our planet was actually round This woodcut from 1475 illustrates the firmament or sky that people believed separated the Earth from the heavens or waters above it It is described in the Genesis creation narrative in the Hebrew Bible Christian Old Testament 7
Later most people believed that Earth was a sphere that resided in a spherical universe The sphere was after all the most perfect of all geometric shapes and the Earth and its cosmos were perfect But these scientists also observed that a ship would disappear over the horizon and safely return so a sphere made practical sense as well 8
Blame Gravity Why are Earth and other planets round Gravity pulls toward the center of a planet or star which pulls everything down into a sphere But planets and stars are not really perfect spheres Because they spin they bulge out a bit around the middle A few hundred years passed before the Greeks used mathematical calculations to figure out that Earth really was a sphere They were even able to figure out Earth’s diameter by using trigonometry Aristotle a Greek philosopher and scientist from the fourth century BCE was the first to theorize that our planet was the center of the universe And Earth was stationary meaning that it didn’t move at all The sun moon planets and stars moved around it For almost 2,000 years Aristotle’s theories were considered to be fact It appeared that the sun and the moon both rose and set The moon stars and planets seemed to move across the night sky And the ground felt stable it certainly was not moving Obviously planet Earth was a stationary thing and everything in the sky above rotated around it Aristotle 384 322 BCE 9
