Before the days of cell phones, laptops, tablets, desktops, tv, radio, cds, cassette tapes, movies and even books, people had to entertain themselves somehow. There was the good old campfire storytelling known as mythology, and there was just lying on your back and gazing at the stars… And when you do that regularly, you can’t help but notice that some lights in the sky move greatly and predictably while others seem fixed.
I personally hardly know anything about the nighttime sky, mainly because I just glance at it once in a while, but the people in ancient times kept a carefully detailed record over hundreds or thousands of years of the changes in the lights in the sky. Many thinkers tried to make sense of these observations to understand the world and their place in it. They also tried to understand and predict eclipses, since these were such terrifying omens.
Greek astronomy was based on the systems developed by Babylonian and Egyptian astronomers, whereas societies in the Americas, China and India developed their own. Babylonians, some 6,000 years ago, erected watch towers to scan the night sky, mapped the stars and the observable planets, and recorded their observations meticulously on clay tablets. This provided the basis for the elaboration of the first calendars, essential for the planning of planting and harvesting crops and the timing of religious ceremonies.
Careful observation, records kept through generations, recognition of patterns and early mathematics were the tools of the ancient astronomers, and with these basic tools, they discovered many basic facts about the solar system.
Many people today still believe the Earth is flat (!!!), an antiquated idea, you would think. 204
Well, actually, by the 5th century BC, the fact that the Earth was a sphere was widely accepted, because during a lunar eclipse, the shadow of the Earth on the moon is clearly round. Another proof is the way a ship appears on the horizon, where the top is seen first. If the Earth were flat, you would see a tiny speck, getting larger as it approaches, but clearly the entire ship, and not appearing from top to bottom.
<PERSON> of Samos believed that the solar system was heliocentric. He also calculated the circumference of the Earth based on information gathered during a lunar eclipse. <PERSON> later used a different approach, measuring the shadows cast at noon by the sun in 2 different locations. <PERSON> of Alexandria created a wealth of astronomical knowledge and held the geocentric version of the solar system, which remained prominent until debunked by <PERSON> more than a thousand years later.
Still, the Ancients got a lot right with their limited means! 489