However, it's important to note:
* Pythagoras's theory was based on philosophical arguments and observations, not direct empirical evidence. He reasoned that the Earth must be spherical because the moon, sun, and other celestial bodies were spherical.
* The idea of a spherical Earth was likely already circulating in ancient Greece before Pythagoras. There is evidence of the concept existing in pre-Socratic philosophers.
Aristotle (4th century BC) provided more concrete evidence for the Earth's sphericity through observations like:
* The changing shape of the Earth's shadow on the moon during lunar eclipses.
* The observation of different constellations in different parts of the world.
Eratosthenes (3rd century BC) further solidified this concept by calculating the Earth's circumference with remarkable accuracy using geometric principles and observations of the sun's angle at different locations.
Therefore, while Pythagoras is often named as the first, the understanding of Earth's sphericity developed over time through various contributions from different philosophers and scientists.
