* Ancient Greek Philosophers: While not definitively proving the Earth was round, Pythagoras (6th century BC) theorized a spherical Earth based on philosophical and aesthetic reasons. Aristotle (4th century BC) provided more empirical evidence by observing the Earth's shadow on the Moon during lunar eclipses (which always appeared curved), and by noting that different constellations were visible in different parts of the world.
* Eratosthenes (3rd century BC): He is often credited with the first accurate measurement of the Earth's circumference, using the difference in the angle of the sun at two different locations on the same day.
* Later contributions: Through the Middle Ages and into the Renaissance, further observations and calculations by scientists like Al-Biruni (11th century), Christopher Columbus (15th century), and Ferdinand Magellan (16th century) reinforced the idea of a spherical Earth.
Therefore, it's not accurate to say that one person "discovered" the Earth is round. Rather, it was a growing understanding built upon the contributions of many individuals throughout history.
