We all know the Earth is round--right? Well, apparently not all of us. There is an actual group of people, the Flat Earth Society, who whole-heartedly believe that the earth is flat. This idea comes from the fact that while standing on the Earth's surface, we cannot see the curvature of the Earth. It is also believed that the edge of this flat plane is ringed with a wall of ice. As ridiculous as that may seem, it is a rather thought-provoking concept. But how do we know that Earth isn't flat?
For starters, no one has ever documented the edge of the Earth nor its giant wall of ice. Also, let's not forget the fact that scientists have been explaining how we know the Earth is round since the third century BC. The Ancient Greeks came to the conclusion that the Earth is round by studying the sun and the shadows it cast in different places at the same time of day. The truth is, Earth is so enormous that from a person's vantage point on the ground, its curvature is simply impossible to see.
Let's take a more layman's look at the proof that Earth is indeed spherical. Imagine a vast plane with but one tree in the center. If the earth were flat, your vision would extend exactly as far while standing at the base of the tree as it would when at the top of the tree. However, the higher you climb, the farther you can see. That's because parts of Earth that were not visible while you were on the ground were hidden from view by its curvature and are now visible because your position has changed.
Another way to explain the Earth being round is the existence of time zones. For example, when it's 12:00 p.m. in New York, the sun is in the middle of the sky. Meanwhile in Beijing, China it's 12:00 a.m., and there is absolutely no sign of the sun whatsoever. This can only be explained if the world is round, and rotating around its own axis. At a certain point when the sun is shining on one part of the Earth, the opposite side is dark, and vice versa. Another point to be made is if the sun had a spotlight-like appearance and the world was flat, we would see the sun even if it didn't shine on top of us. Similarly, you can see a cup in the light of a desk lamp while you are sitting in the dark.
While Earth may not be a perfectly symmetrical sphere, it is far from flat. Maybe now flat-earthers could focus on proving that the moon is made of cheese.
