Exploring the Ancient Perceptions of Outer Space: How Early Civilizations Imagined the Cosmos

It was a spring day in 1900 when a group of Greek sponge divers discovered a shipwreck off the coast of Greece. Among the treasures they found was a complex cosmological calculator – one of the world's first analog computers – made by the ancient Greeks between the 3rd and 1st centuries BCE. But as fascinating as the Greeks' knowledge of the universe was, their beliefs were based on those of an earlier civilization: the ancient Babylonians, who were the first astronomers and predicted eclipses and the length of a year.

The Babylonians imagined their world as an oyster surrounded by water, with a dome-like sky above. The ancient Egyptians, on the other hand, believed the sky was a rectangular box or a vaulted metal lid, with deities of the sun and moon sailing along the river flowing upon an elevated gallery running around the inner walls of the box. The Greeks imagined their world as a floating disc surrounded by oceans and a mythical river encircling the world. But these theories were soon debunked as Greek scientists made tremendous advances in understanding the universe. They developed the heliocentric theory, which mapped the planets in order of their distance from the sun, and the earth-centered model, which was eventually toppled in the 16th century.

Back in 1900, Greek sponge divers were in for a remarkable discovery when they stumbled upon an ancient Roman shipwreck laden with riches. Among the treasures lay an analog computer, a cosmological calculator built by the ancient Greeks between the 3rd and 1st centuries BCE. However, it's worth noting that the Greeks weren't the first to pursue astronomy. Ancient Babylonians were the first astronomers using watchtowers and clay tablets who could predict eclipses and infer year lengths. But their concepts of the universe seem peculiar to the modern person, with the planet being akin to an enclosed oyster surrounded by water, and the sky being a solid dome. In contrast, the Egyptians' universe was rectangular, while the Greeks imagined a floating disc surrounded by water, a majestic & mythical river. With time, their more refined understanding saw the Greeks develop the heliocentric theory that correctly mapped the planets in order of their distance from the sun, while the earth-centered model stayed afloat for as long as 1,400 years before being toppled in the 16th century.

While we might consider such ancient cosmologies unsophisticated today, people back then did find innovative ways to entertain themselves, such as creating animated carvings that seemed to move in flickering firelight. Ancient cultures like the Greeks and Egyptians created clay toys and board games like Senet and marbles, which have also been around for over five millennia. Even the yo-yo finds roots in an ancient era and was utilized during battles before being fashioned into a child's toy.

Even though the ideas of ancient civilizations about the world often seem naive to us, they still managed to create forms of entertainment that persist to this day. Cave people, for example, created animated carvings that came to life in the flickering firelight, while ancient Egyptians and Greeks played with dolls and balls made of clay. Board games like Senet and marbles have been around for over 5,000 years, while the yo-yo has been around for over 2,000 years and was often used in battle before becoming a toy.

As we journey back in time, we can also witness the birth of the solar system. 4.5 billion years ago, a planet called Thea collided with Earth, and the debris formed what we now know as the moon. Thea's remains are still on Earth today, as two gigantic lava patches beneath Africa and the Pacific Ocean. The collision also gave Earth its lithospheric plates, which led to the movement of carbon and the creation of life over the course of nearly 4 billion years.

Our journey continues to Europa, one of Jupiter's moons, which is believed to have a huge ocean beneath its icy crust, where simple bacteria could be thriving in thermal springs. And just like that, we are reminded of the mystery and magic of the universe, of the magnificent and terrible forces that created and sustain life.