The first ship to sail around Africa left from Egypt sometime around 600 BC. Their only goal was to find another way to the straits of Gibraltar. But by watching the sky overhead, they discovered something they’d never expected: the first hints that the world is not flat, but round.

When they reached the southern tip of Africa and started sailing west, the sailors reported back to their homes that they noticed that the sun’s position had changed in the sky. Now it rose and fell in the north instead of the south.

It was a small detail – but for a civilization that believed the world they lived on was flat, it was a discovery that challenged everything they thought they understood about their world. And it was such a radical discovery that most people refused to believe it.

[Read the full article at Ancient Origins.]