🌍 How did people figure out that the Earth is round?

Long, long ago, people thought the Earth was flat like a pancake 🥞. But smart people noticed that when ships sailed far away, they slowly disappeared from the bottom up! If the Earth was flat, the ships would just get smaller and smaller, but they don't! 🌊

Also, when there's an eclipse (when the Moon covers the Sun), the shadow on the Moon is round. That's another clue that the Earth is round like a ball! 🌑

People figured out the Earth was round in many clever ways! 🧠 Here are some:

• Ships and horizons: When ships sail away, their hulls disappear first, and then their masts. This wouldn't happen if the Earth was flat—it's because the Earth curves! ⛵
• Shadows and eclipses: During a lunar eclipse, the Earth's shadow on the Moon is always round. Only a round object casts a round shadow! 🌒
• Stars and travel: Ancient Greeks noticed that stars looked different in Egypt than in Greece. On a flat Earth, stars would look the same everywhere! 🌟

How Ancient Scientists Proved the Earth is Round

People have known the Earth is round for over 2,000 years! Here's how they figured it out:

1. Observations from Travel

Ancient Greeks noticed that:

• The North Star appears higher in the sky the farther north you go.
• Different constellations are visible in different places.

This wouldn't happen on a flat Earth—it's evidence of curvature! 🌌

2. Lunar Eclipses

During eclipses, Earth's shadow on the Moon is always round. The only shape that casts a round shadow from any angle is a sphere. 🌑

3. Eratosthenes' Experiment (240 BC)

He measured shadows in two cities at noon on the same day. Using geometry, he calculated Earth's circumference—and was only 2% off the real value! 📏