Thinking Outside the Oblate Spheroid

People who believe that most people in Columbus's day thought the earth was flat, have a crappy education. The sphere theory was generally accepted since before Christ.

What I did foolishly believe, however, was that Megellan's around-the-world journey provided the conclusive evidence of a sphere. I didn't realize until yesterday that my conception was all wrong. I didn't take into account that Flat Earthers believe the earth is a disc with the North Pole is the center, and that the earth is surrounded by a 150 foot wall of ice (which is "south," away from the north pole, in all directions). Imagine a vinyl record. The North Pole is the hole in the middle. So Magellan's crew could have just traveled around the disc. Travelling around the world does not prove that the earth is a sphere. I feel like an idiot.

Now I'm curious whether the Flat Earthers have an explanation, aside from conspiracy, about the distance between the sub-equatorial continents, which are much closer than should be expected. For the earth to be flat, the distance around the world at the 45th latitude south of the equator must be much, much, longer than the 45th latitude north of the equator, right? After all, a record groove one quarter in has a much larger circumference than the groove three quarters in.

I wonder if the explanation is really simple, like the explanation how one can travel around the world on a flat earth. Or if some complex math or physics is involved, or if there is no possible explanation at all.

Don't worry, people. I do not believe in a flat earth. I'm just fascinated by how much of it can be explained before we get to "the space flights were staged." It's an education in perspective.