The Earth is more flat than it is spherical.

I'm actually very surprised that the opponent is so passionate about his position. It is a good sign that this debate is going to be a good, thorough one. The opponent has opened with acceptance and clarification, meaning it is my responsibility to produce the first argument. Before I get started, I'd like to discuss a few things the opponent cautioned against. "Theories"The opponent's first warning was against using "theoretical" constructs such as gravity to explain the shape of the Earth. He further stated that we should not assume a heliocentric system, the existence of a moon, that the Earth is moving through space at great speed or that it is spinning. Many of these concepts are important pieces of physics that help describe the shape of the Earth, but for the sake of the debate I will not simply assume that these things exist. Rather, if I use "gravity" as part of an argument, I will demonstrate the existence of gravity using emperical evidence and/or logic. Let's get started. 1. Gravity exists and demands a spherical Earth.The existence of gravity would directly imply the existence of a flat Earth. We should first demonstrate that gravity exists, as the assumption alone does not sate the opponent. We all know that gravity exists to some degree based upon our own personal experience. Ie, we are fixed to the surface of the Earth and any attempt to leave the surface of the Earth ourselves generally results in us returning to the surface. For instance, if I were to stand up and jump, I would momentarily leave the ground, but quickly return. If I were to let go of a ball at the top of a cliff, the ball would fall until it hit the ground.This is evidence that there is indeed some force that pulls thing toward the ground. The nature of this force, from the perspective of a single man however, might be unkown. Let's now look at whether this force is constant or whether it changes based upon other phenomena. This is important to look at. If the Earth were flat and other celestial bodies did not exert gravity on the planet, one would expect the force earlier mentioned to remain constant despite the position or orientation of the celestial bodies above. This turns out not to be the case.The opponent briefly mentioned that the Earth might be a "moonless" thing, so we will refer to the moon here simply as the observation of a constant, bright, moving light in the sky. (The observation of the moon.) We won't question the nature of the moon. Instead, we'll simply look at whether it interacts with the Earth. Under a "no gravity" assumption, the moon shouldn't have any affect upon the Earth. However, we do notice that the tides change according to the position of the moon. Sea levelsalways rise when the moon is overhead and always lower whenever the moon is not visible. (Or as a globe-head would say, while the moon is on the opposite side of the planet.) The oceans are so large and utterly heavy that it would be unreasonable to assume that some man made force was causing this movement. The amount of energy necessary to move the oceans in such a manner does not currently exist. (Nothing anywhere near close to it exists, in a manmade construction.)Since man isn't doing it, we are left with the assumption that the moon is in some way causing the rise and fall of the tides. Under the current model, we assume that two things with mass are attracted to each other and we call this thing 'gravity'. This fact has been varified in various experiments, which generally involve measuring the force that attempts to draw two objects of mass toward one another. [1]This apparent attraction between any two masses can be experimentally verified and has been called gravity. Unless the opponent has some other scientifically verified or implied explanation for this force, we can comfortable assume that gravity exists.Because of the existence of gravity, we know that planets must be spherical in nature. This is because, during a planets formation, particularly high elevation dusts and materials are drawn to lower elevations. One can visualize this by watching sand fall from an hour glass. The sand does not simply create an upright pillar, but instead forms a sort of "normal curve", with respect to the bottom of the hourglass. This is because gravity is largely acting in only one direction. When considering a single gravitational "point" in space, it is easy to see how the falling sand would form a sphere.A flat Earth is not consistent with our understanding of gravity, as the center of gravity would force the external edges of the flat "plate" toward the empty areas (above and below the plate), forming a ball like object.2. View from airplanes.We can furthermore understand that the Earth is curved by the view one sees when looking from an airplane. The opponent claims (in the comments) that photos from an altitude are taken with a fish-eye lens, in order to distort the actual flat shape of the Earth. However, anyone who has been on an airplane can clearly note the subtle, but existent curvature of the Earth. Many photos have been taken from airplane windows as well, usually with devices like the iPhone which do not have a fish-eye lens. To claim that these photographs are faked approaches delusion, as it would be nearly impossible for a governmental agency to apply a curvature to these photos and simultaneously brainwash anyone who has ever been on a plane into believing that they saw curvature where none existed.3. Other spherical bodies (can be seen from telescope)If we know what other celestial bodies look like, we can predict what our own looks like. In other words, if all other observed planets form spheres, it is highly likely that our planet is also spherical. Again, the opponent may claim that photos of other planets released by the government have been tampered with, so I'll only talk about what could easily be seen with a telescope in your own back yard.With a mid-range (<$1000) telescope, one can easily see Jupiter in great detail. In the viewer, this planet would look perfectly round. Given this, it is still possible that Jupiter is also flat and that it's simply facing us. This notion is shortly defeated, however, when one looks at Jupiter again at a different time of the year and notes that the surface has dramatically changed. Again, one could simply say that the storms have shifted around the flat surface.This is disproven when noticing the existence of a mostly stationary storm called the "Great Red Spot". The Great Red Spot noticeably shifts to the left, then out of view, the back again on the other side of the planet. This implies that Jupiter is not a flat disc facing toward us, but is instead a spherical object. Observations of all other planets in the system can be made in a similar fashion, with only the moon's surface not changing. (Which we call tidal locking.)4. The unlikelihood of an international conspiracyIt is conceivable that a single government may desire to and have the means to fool its citizenry into believing something that is not true. However, this issue is both large and international in scope and is a view held by scientists in all countries. There is no reason to believe that an international conspiracy a) exists or b) could exist. Consider other powers that be like Russia and China. Nothing would illegitimize the scientific efforts of the United States more than if one of those two countries managed to prove that the Earth was flat. It cannot be said that all three of these countries are just living under a "delusion", unaware of the shape of the Earth, as all three countries have had their citizens in space using their own technology. This means each country has the "means" to expose the Earth as flat, if it truly were. And given the political advantages of proving that another country's government has been lying to its people, there is no reason this information would have remained a secret all these years. There is no conceivable advantage to keeping this a secret, as no one is benefitted by this.5. No "end of the Earth" ever documentedIf the Earth were flat, it would have an "edge". In other words, you could not go in one direction and continue in that direction without reaching the end of the Earth. On a spherical globe, however, this is completely possible. There are a great number of people with cameras and internet. If there were an "end of the Earth", it is highly likely that someone would have taken a photo of it by now. No governmental agency has the power to monitor the internet to the degree that they could prevent any attempt at posting such a photograph. Furthermore, there have been multiple instances in which people have circumnavigated the globe by plane. If the world were flat, this would be impossible. The opponent would be forced to contend that these circumnavigations were all faked to further this conspiracy, something that is again extremely unlikely.6. Sheer evidence overload.Finally, we'll look at the sheer amount of photographic and video evidence that exists. While it is possible that a government agency could fake their photos, it doesn't account for the other government agencies and private companies that also take photographs. Private companies in particular put a damper on the entire flat earth idea, as many of them have their own satellites in orbit that take videos and pictures on a regular basis. Even if we assume the governments somehow managed to attach fisheye lenses to these satellites, it still wouldn't explain the pictures. Fisheye lens distort the image, but they do not destroy information, whereas two satellites on opposites ends of the earth can take two completely unique photos. (Different land masses/oceans.)ConclusionThis is the basic "globe head" intro. I've tried to use arguments that don't rely heavily on one government's testimony. I look forward to the next round.Sources:1 - https://cosmosmagazine.com...