The World Is Flat?

So everybody knows that Christopher columbus discovered that the New World in 1492 which eventually became America. He was looking for a trade route and I do not think he found one. However he discounted a pseudoscientific myth that the earth is actually flat. Today everybody knows that the world is round. Except for the people at the flat earth society, they firmly believe that the earth is a flat plane or disk. Which is incredibly stupid because people have been to the moon and we have footage of the earth that shows it is not a disk and is not flat. We have photos that show the earth is round. Many of these flat earth beliefs were understandable in the middle ages. However now, it just seems stupid. The flat earth society firmly believes that the earth being round is an elaborate hoax. They acknowledge that the moon other planets and the sun are round. However they believe that the earth is a flat disk with the north pole in the center. The continents and oceans surround the disk. On the edge of the disk is a 150 foot wall of ice holding the ocean in. There is even a forum section were you can debate with them over your theories. Which will usually be shot down even if you show evidence that the earth is round. Normally i respect and understand other peoples thoughts and beliefs. However, the flat earth society are very strange. I just think that people like conspiracy theories. I really do not understand why this group of people believe in something that is obviously false.