The world is flat.

I'll take this debate again, because I just love proving that the world isn't flat. I will be assuming that first round is acceptance + argumentation, since the opponent led with arguments. I will organize this by starting with my response to each of my opponent's claims, then providing my case as to why the Earth isn't flat -- but instead round. Opponent Claim 1The opponent claims that upon looking outside his window, the ground appears flat. He further generalizes that if this part of the earth seems flat, the rest of the Earth must also be flat. Since my opponent attempted to set up his arguments in a logical fashion, I will respond with the logical fallacy the opponent makes, if such a fallacy exists in a clearly stated form. For this claim, the opponent commits the "Fallacy of Composition", which is worded as such: The false assumption that the whole has some characteristic because a part of the whole has said characteristic. It is clear the Fallacy of Composition is being used here, as the opponent uses a small subset of the surface of the Earth and assumes the entire surface of the Earth retains the characteristics of said subset. Allow me to present some counter arguments. If the opponent's house were located on top a hill, the opponent would look out his window and see the Earth sloping downward. By his argument, he might well assume the Earth is round. If the opponent's house were located next to a mountain, he might look out his window and see the Earth is sloping upward. By his argument, he might assume that the earth is round, but that we are on the inside of the earth. (Imagine a ring structure in which we are located on the interior. Lastly, there is the case the opponent mentioned, in which he is on a plain (geographical term) and sees only flat land. He might well assume that the Earth is flat. The issue with the argument, given these counter examples, is that all such places exist on the Earth as we know it. There are hills, there are mountains and there are plains. As such, local observations of relative height are not adequate in determining the global shape of the planet. Opponent Claim 2 This argument is essentially the same as the first claim. It's based upon local observation. One might remember that man made structures can take any shape. Man can create a bowl like structure, meant for the pleasure of skaters and rollerbladers. Man can create a hill or wall like structure, meant for stopping tidal surges in cities prone to this. Man can create flat structures, meant for the parking of cars next to the local supermarket. Besides the flaws this argument has in common with his first claim, there is the additional flaw of assuming that manmade structures must necessarily follow the natural curvature of the Earth, which is apparently false. Opponent Claim 3I am only now realizing that this may be a partial troll debate, since I accepted before reading the opponent's arguments. My opponent claims that he saw a waterfall at the edge of the Earth, proving the idea that the Earth is flat. There are two flaws with this. The first is that movies can utilizes computer generated special effects that cause certain movie attributes to seemingly behave in non-physically possible ways. [See every science fiction movie, ever.]The second is that if there was a waterfall at the edge of the earth, it would be quite large. Imagine the Earth is flat and that it looks like a coin. Anywhere along the perimeter of the coin that the oceans touch, there would necessarily be a waterfall. Since some 75% of the Earth consists of Oceans, we might assume that 75% of the perimeter of the coin would have waterfalls. The issue comes with the fact that such a scenario would quickly empty the oceans. Just as if you spill water on a flat surface, it will drip off the edges -- so would the oceans drip of the edges of the world if it were flat. We know that ocean levels are currently rising (due to melting ice), so it is clear that the world cannot be flat, since we aren't losing water. Opponent Claim 4This argument is the exact same as the previous, except it regards pictures, rather than movie clips. My refutation to the previous claim also covers this. It's worth mentioning it's even easier to convincingly edit a picture than to convincingly edit a movie. ----------------------------------------Why the Earth is RoundFirst, we can look at photographic evidence. Many photographs of the Earth have been taken from satellites orbiting the planet. Regardless of which angle a photo is taken from, the Earth appears to be a circle. If the Earth were flat and circular, photographs of Earth from space would appear circular from only one angle. From others, it would appear to be an ellipse or simply a thin line, if taken from the side view. Clearly these photos would not be possible if the Earth were not spherical. Next, we can notice that if the Earth were flat, there would be a distinct edge (where one might fall off.) However, Man has created maps of the world that do not indicate a 'falling off', or edge. There are very few unmapped places left, implying that an edge likely does not exist. Additionally, all parts of the globe have been seen from satellite imagery and an edge has not been found. Given the size the edge must necessarily be if it exists, the fact that we haven't found one implies its non-existence. Additionally, we can look at the force of gravity and understand why planets are round. As a planet forms, it draws matter toward it. Additionally, the forming planet is rotating. This causes rough edges to be rounded out by new matter being drawn toward the planet. A flat planet cannot form through any scientific means. Additionally, if one did somehow exist (maybe a god created it), it would quickly collapse into a round shape, again due to gravity and rotation. We can observe that the earth often casts shadows on the moon. These shadows always take the form of an oval shape, no matter what specific orientation the Earth is currently at. This implies that the Earth is round. If it were flat, the shadows on the moon would take a radically different shape dependent upon the orientation of the Earth as it relates to the moon (and sun).Another observation supporting the idea that the Earth is round was made long ago. People noticed that as ships left a port, they would appear to sink into the ocean as they got further and further away. This was due to the fact that the earth is round, causing the ship to slowly become hidden by the Earth itself. In a flat world, one would be able to get a telescope and watch a ship sail into the ocean infinitely. This is not the case.Lastly, I'll point out that planes have circumnavigated the globe before. What this means is that they have started at point A, travelled along the circumference of the Earth, and ended up back at point A. This would not have been possible if the world were flat, as the plane would reach a point where the Earth suddenly ended. This did not happen, again showing the Earth to be round.