factually
Index/Topics/Earth's curvature

Earth's curvature

The shape of the Earth, whether it is curved or flat, and methods to demonstrate its curvature without using space imagery.

Fact-Checks

1 result
Jan 19, 2026

What experiments and simple observations reliably demonstrate Earth's curvature without relying on space imagery?

A suite of low‑tech, repeatable observations and simple experiments—ranging from Eratosthenes’ shadow measurements to watching ships disappear hull‑first, to level‑laser and pendulum tests—provide rel...