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Wellsprings
geography

The Sphericity of the Earth

σφαιρικὴ γῆ

Watch a ship sink hull-first beneath the horizon: the earth, the Greeks reasoned, must curve away as a perfect sphere.

Long before any sailor circled the globe, Greek thinkers concluded the earth was a sphere by reading the evidence in the sky and sea. Aristotle assembled the classic proofs: the earth always casts a curved shadow on the moon during an eclipse, new stars climb into view as you travel south, and ships vanish hull-first over the horizon. Plato had already imagined the earth as a round body resting at the center of the cosmos, and centuries later Ptolemy made sphericity the bedrock of his mathematical astronomy.

Where this idea shows up

2 Greek sources·2 Jewish-canon citations

Where to read it