Um problema do século XV

Here are some reasons why you may think that Earth is actually a rotating sphere. For one, some of the ancient Greeks said so: if the moon is round, Earth must be, too (Pythagoras); as you move north or south from the equator, you see a changing array of stars and constellations (Aristotle); you can calculate Earth’s circumference by comparing the lengths of the shadows of two tall sticks placed many miles apart (Eratosthenes). More recently, we’ve noticed that solar noon—the point in the day when the sun is highest—doesn’t happen everywhere on Earth at the same time. (Time zones were invented to address this dilemma). Also, the higher you climb in elevation, the farther into the horizon you can see; if Earth were flat, you’d see an equal distance—to the edge of the world, with a strong enough telescope and an unobstructed view—regardless of altitude.