- Why did everyone start to hate the Russians if the U.S. did the same thing in Afghanistan, Iraq?
- What needs to be corrected in the management of Russia first?
- Why did Blaise Pascal become a religious man at the end of his life?
- How do I know if a guy likes you?
- When they say "one generation", how many do they mean?
At that time, there were simply no accurate enough maps to calculate this. For example, the Uqba Mosque, 670, and the real direction to Mecca along the arc of the great circle:
At the same time, the very fact of the Earth's spherical shape was naturally well-known among more or less educated people of that time, even in the Islamic world, even in the Christian one.
Well, not exactly, but it's possible. The fact that the Earth has the shape of a ball was known in ancient Greece, and Arab scientists had access to the Greek heritage and actively cultivated it.