Earth is flat locally, too, but if you travel along a line for 40,000 km, you return to your starting point. That doesn’t happen on a plane. For this, the diff

Earth is flat locally, too, but if you travel along a line for 40,000 km, you return to your starting point. That doesn’t happen on a plane. For this, the difference similarly only shows up over longer distances. That means more iterations. Spaceships will return where they left off. Also, the specific topology matters: if a spaceship makes a tour around the world, it may appear to have flipped over on a Klein bottle.