Question

How did we know for the first time that the earth was round not flat? ​

Answer 1

Answer:

We knew this when scientists explored solar system by spaceship and they also discovered that earth revolves around the sun.

Answer 2

Answer:

The earliest documented mention of the spherical Earth concept dates from around the 5th century BC, when it was mentioned by ancient Greek philosophers. In the 3rd century BC, Hellenistic astronomy established the roughly spherical shape of the Earth as a physical fact and calculated the Earth's circumference.

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