Earth's shape can be tested in surprisingly simple ways without relying on space photographs. The strongest part of the ...

The Earth is round, and we know this from detailed measurements and geometric inferencing based off satellites with lasers. Earth is often described as a circle or an oval, but it is neither. As the ...

Aristotle, working in Athens in the 4th century B.C., discovered that the world is round. Aristotle first discovered that during solar eclipses, Earth’s shadow always appeared on the Moon’s surface as ...

Our beautiful big round ball of a planet is not, in fact, a perfect sphere. As it spins about on its axis, whirling around the Sun, rotation causes it to bulge at the equator and flatten at the poles.