Earth is just as flat as it's round =================================== [Published 2023-01-31, Updated 2023-02-18] Some people claim that the earth is flat. Some people think that those people are stupid and say that the earth is obviously round. Let's see who's right. I'd say that it's not very obvious. First, we need to think about what truth is and what can count as a true statement. If you say that the earth is round, you are ignoring all the mountains. If you say that it's flat, you are ignoring the view from far away. There is also the question about whether "is" means "looks like" or whether it's a property of the object itself (is everything black when the lights are off?). Only what is relevant counts ---------------------------- I think the most important reason that calling the earth flat makes sense is that we sometimes describe things based on the parts of it that are relevant. Here are a few examples of that; would you say that doing any of the following things is wrong? * You call it a rainbow because it looks like a bow but if you could see the whole thing you would call it a circle. * You say that the sun rises but it's mostly the earth that rotates. * You say that you are standing still but according to the theory of relativity, movement is relative and nothing is really still. * You say that the jar is empty when there is actually a little bit left that you don't care about, and you also don't care about all the air that's inside it. * Mathematicians may say that something is so large that it's almost infinite. That's because it's so big that it's bigger than anything else they care about so it doesn't matter if it's infinite or not. In reality, the largest number you can think of is not even a little bit close to infinity. * You say that the house is red even if only the outer walls are red. As you can see, we often say things that are only approximately true or only true enough to be useful in some situations. We ignore things that currently don't matter. If you say that "the earth is flat" is false, I expect that you never do anything from the list above. Here is an example. When you stand on the surface of earth and everything around you looks pretty flat, it doesn't matter that it looks round from space because that's not where you are right now. If you kick a ball, all you care about is that the earth is flat enough that the ball will not roll away and large enough that you will not overshoot it. In that situation you could call the earth an infinite plane. Ok, so we can pretend that the earth is flat, but does that really mean that it IS flat? The earth is flat if you ignore its global shape just as much as it's round if you ignore its local shapes and just as much as the sun rises. The only difference though is that "the sun rises" is probably a more common statement than "the earth is flat" so maybe that makes it more true. Does that mean that things become true if you say them enough times?