* Ancient Greeks: Pythagoras (c. 570-495 BC) was among the first to propose a spherical Earth based on philosophical arguments. Aristotle (384-322 BC) provided more concrete evidence, noting observations like the changing constellations as one traveled north or south, and the Earth's shadow during lunar eclipses being round.
* Eratosthenes: Around 240 BC, Eratosthenes of Cyrene calculated the Earth's circumference with remarkable accuracy, providing strong evidence for its spherical shape.
* Other Ancient Civilizations: It's likely that other ancient civilizations, like the Indians and Chinese, also had theories about the Earth's shape, but their writings are less well documented.
It's important to remember: The concept of a flat Earth wasn't widely accepted in the ancient world. The idea that the Earth is flat is a modern misconception, largely spread through popular culture and misinformation.
Therefore, it's more accurate to say that the idea of a spherical Earth evolved over time through the observations and deductions of various thinkers, with Eratosthenes playing a key role in providing empirical evidence.
