1. Ships Disappear Hull First: As ships sail away from shore, their hulls disappear below the horizon before their masts. This happens because the Earth's curvature causes the ship to gradually sink below the observer's line of sight. If the Earth were flat, the entire ship would shrink proportionally, not disappear hull first.
2. Lunar Eclipses: During a lunar eclipse, the Earth's shadow falls on the Moon. The shape of the shadow is always circular, regardless of the Earth's position relative to the Moon. This circular shadow can only be cast by a spherical object.
These are just two examples, and there are many other ways to observe and prove Earth's spherical shape.
