: As early as the 7th century BC, the Babylonians mapped the world as a disc surrounded by "bitter waters," beyond which lay seven mystical lands. These regions were described as the place "where the winged bird ends not his flight".
Modern science replaces monsters with abstract boundaries that define the limits of human knowledge.
Throughout history, civilizations have populated the perceived "edges" of the world with legends and monsters. Space Legends At the Edge of the Universe
: At the very edge of our visibility lies the CMB, a "relic" radiation from the hot, dense early universe.
: Many ancient Greeks believed that traveling far enough toward the world's edge would lead to savage lands inhabited by dog-headed people and tigers with human faces. : As early as the 7th century BC,
: The "edge" of our universe is not a physical wall but a limit of information. Because light takes time to travel, we can only see objects within a bubble roughly 93 billion light-years in diameter.
: In Finnish mythology, the world's edge was known as Lintukoto ("home of the birds"), a warm, paradise-like region where birds traveled for the winter along the Milky Way. 2. Scientific "Legends": Defining the Cosmic Edge : The "edge" of our universe is not
: Einstein’s theory of general relativity suggests that if the universe has "positive curvature," it could be finite but without an edge—much like the surface of a sphere where you can travel forever without hitting a boundary. 3. Modern Cultural Interpretations