Question: Why Would Earth Be Flat When All Other Planets Are Not?

Answer

I will answer this question with a question of my own: why would the crow in the above picture be white when all other crows are black? White crows exist, but they are extremely rare. Most planetary bodies are spherical. According to Flat Earth Theory they are smaller and much closer to the surface of the Earth and orbit above its surface. But this does not entail that ALL planets, including Earth, are spherical as well. As discussed elsewhere on this site, a planetary body with an upward facing surface is alone capable of supporting life as we know it. Any organism that does not directly attach itself to the ground would eventually fall off the bottom of a spherical planet. 

Question: What Are The Surface Dimensions of The Flat Earth?

Answer

The ancient Greek mathematician Eratosthenes measured what he erroneously thought was the circumference of the ball earth. 

https://upload.wikimedia.org/wikipedia/commons/thumb/b/b3/Eratosthene.01.png/220px-Eratosthene.01.png

Using a conceptually genius approach, he calculated the circumference of a spherical earth by measuring a shadow cast in his own city against the fact that no shadow was cast at the same time of day at a well located in a nearby city that was a known distance away. Using these variables, he calculated the circumference of the ball earth:

https://commons.wikimedia.org/wiki/File:Eratosthenes%27_method_for_determining_the_size_of_the_Earth.svg

But his experiment erroneously assumed that the sun is far away and that it emits rays of light in a parallel fashion. However, if the sun is smaller and much closer to earth's surface, when directly overhead it would cast rays perpendicular to the ground, producing no shadow. For an object a short distance away it would cast light at varying angles, causing a shadow to be cast. This shows that while Eratosthenes exhibited exemplary critical thinking and empirical observation, he failed because he made one major problematic assumption: he assumed that the sun is large and farther from Earth. On a Flat Earth with a small local sun, the same effects would occur as on a ball earth. If you are interested in how Eratosthenes actually performed this experiment then check out this (spherist) video by Carl Sagan...

Eratosthenes shows us that all measurements of physical reality are strongly impacted by the assumptions we start out with. That being said, what are the surface dimensions of the Flat Earth?

Fig 1

The surface area of the spherical earth, 196.9 million miles squared, serves as an approximate model for determining the entire surface area of the Flat Earth. Like Eratosthenes, some spherist measurements are usable, even though spherists themselves based the data on incorrect assumptions. An equatorial measure of the circumference (Fig 1) carves out a portion of the Flat Earth that is about half its total surface area, or 98.45 million miles squared. Multiplying the equatorial circumference by a value slightly larger than double (say, 2.2) gives us a total circumference as bounded by the ice ring of 98.45miles x 2.2 = 54,782.2mile (Fig 2).

Fig 2

From here, it is easy to find the diameter of the Flat Earth (As Bound by The Ice Ring) using the equation for the diameter of a circle where the circumference is known: C=兀(d). Substituting our values we get: 54,782.2mi = (3.14)(d). Performing some simple math (divide both sides by 3.14) yields a diameter of: 17,446.6mi (Fig 3). The ice ring itself extends outward to an known distance of many thousands of miles. We will need to wait for the day when real research can be conducted to fully understand the full surface area of the Flat Earth...

Fig 3

As these numbers show, the diameter of the Flat Earth (as bound by the ice ring) is significantly larger than the supposed diameter of the ball earth. Keep in mind that these numbers represent educated estimates. Also, the picture used here of the Flat Earth shows a distorted view of S America, Africa, and Australia. These landmasses are not so large as the picture implies. Pictures produced by NASA also tend to be distorted as well as photoshopped. The above picture is only meant to serve as a visual approximation...

Question: How Thick Is The Flat Earth? What Is On The Bottom?

Answer 

Flat Earth Theory (FET) does not pretend to fully understand physical realities that have not been directly observed. That being said, the Flat Earth does possess a certain size and shape. The most widespread assumption holds that Earth is a cylindrical planetary body with a Flat, upwards facing surface upon which humanity resides. Sperists measures of the ball Earth place its radius at 4000miles. And as this graphic suggests, even mainstream science admits that knowledge of Earth's interior is foggy at best: 

http://www.livescience.com/6959-hole-drilled-bottom-earth-crust-breakthrough-mantle-looms.html

That being said, Flat Earth Theory can offer an educated (though empirically uninformed) guess regarding the dimensions of the Flat Earth. Lets start with the dimensions of the surface. While spherist measurements of Earth's interior commit glaring errors, the measurements themselves represent data that Flat Earth Theorists can utilize with cautionary assumptions in mind. (Please remember that science itself is a corrupted methodology, and that any data appropriated must be done so with caution). It is a common fact of empirical observation that earth contains a supper heated molten interior, as evidenced by volcanoes and other geothermic activity. A significant and sizable outer crust necessarily exists in order to hold back such volatile fluids. The molten layer must therefore be sandwiched between two significantly thick layers of crust. As mentioned, spherist measurements place the radius of Earth at approximately 4000 miles . 

Taking the above measurement as a tentative starting point, an educated estimate of the Flat Earth's proximal (upper; above the molten layer) crust places it at approximately 4000-6000 miles in thickness. The molten layer likely extends anywhere from 1000-2000 miles in depth. The thickness of the Flat Earth's distal (lower; below the molten layer) crust likely corresponds to the thickness of the proximal crust, ranging between 4000-6000 miles. This places the Flat Earth's entire thickness from top to bottom anywhere from 9,000-14,000 in length. Please note that these are only estimates, and that the spherist data appropriated is suspect. However, short of digging through the Earth itself, empirical descriptions of the Earth's interior (Flat or spherical) will remain subjective at best...

So what is at the bottom of the Flat Earth? 

The bottom of the Flat Earth almost certainly consists of the same material composing the upward facing surface. (Remember, contrary to spherist belief there is no reason to assume that up or down does not exist in space. If the universe is finite, thus space almost certainly contains a downward direction towards which all unsupported objects would tend to fall toward). As any material loosely adhering to the bottom of the Flat Earth would have fallen off long ago, the bottom likely displays a coarse surface composed of rock and ice, possibly taking the form of icicles and stalactites. The roof of a cave could resemble the bottom of the Earth, but on a much larger scale...

Question: How Do Day/Night Cycles and Seasons Work On A Flat Earth?

Answer

https://wiki.tfes.org/images/thumb/7/70/SunAnimation.gif/300px-SunAnimation.gif

The above gif illustrates the day/night cycles of the sun. The sun, moon, stars, and planetary bodies are all much smaller and much closer to the surface of the earth. Unlike the earth, they are spherical. The sun does not emit light equally in all directions, but acts more like a spot light as seen above. This is due to an effect I call Variable Luminosity: the sun does not necessarily consist of super heated gases (we wont know for sure until real space travel happens), and only certain portions of its spherical face actively emit light. Locked in a circular orbit above the surface of the earth, the downward facing portion of the sun's sphere actively produces light creating its characteristic "spotlight" effect. "But Why Cant We See The Sun At All Times If What You Claim Is True? At Best Earth Would Only Experience Perpetual Twilight. We Can See The Sun Set On The Horizon!" A question I see a lot, this objection forgets an important fact already mentioned: the sun is much smaller and much closer to the Earth's surface. As it moves over the disk of the Earth it recedes from view, much like if you watched a receding car vanish into a horizon like this one:

Can you see the light of a flashlight being directed at you from 20 miles away? Of course not: perspective and atmospheric density combine to obscure its light from view. The same principles are at work when the sun recedes from view, appearing to "set" on the horizon.

"Ok, So What About The Seasons?"

The model for Earth's seasonality is actually quite elegant. Keeping in mind the above gif as an example of the sun's daily motion, consider this illustration:

https://wiki.tfes.org/Frequently_Asked_Questions

As this image shows, the seasons are caused by an annual expansion and contraction of the sun's orbit above the disk of the earth. During summer in the northern hemisphere (I use the word "hemisphere" merely for clarity's sake) the suns orbit is at its most contracted point. The gradual transition from summer to winter in the north corresponds to the sun's steady, outward orbital expansion. Once the sun's orbit it at its widest, the southern hemisphere experiences summer. This makes more sense than an axial "tilt" taking place on a spherical earth: such a change would necessarily cause noticeable physical effects such as a directional change in the flow of rivers. This is not the case. Explaining the seasons using the Flat Earth model represents a more coherent synthesis of empirically demonstrable phenomena...

Question: If Gravity Doesn't Exist, What Holds Us Down?

Answer

As a force, "gravity" or "the force holding us down" does exist. Though not as round earth theory imagines. One of the most basic facts of demonstrable intuition is that large spinning objects would necessarily eject smaller objects from their surface. Simply put: a round spinning earth would fling us off. The force that keeps us "glued to earth's surface" is the upward motion of the disk of the Earth through space. Called Universal Acceleration, a current of continuous magnetism flows through the universe, carrying objects of sufficient surface area upward in its path. Due to Earth's immense surface area, the Universal Accelerator (UA for short) acts upon its underside propelling it upwards through space. Universal Acceleration makes more sense than gravity, the supposed attractive force exhibited by objects of sufficient mass on smaller objects. 

So how does Universal Acceleration work where gravity conceptually fails?

Early spherists showed a strong tendency to over-explain the universe in terms of cause and effect. Of course, every effect does have a cause, but early spherists quickly assumed that such causes existed in the most readily available object: the Earth itself. It was outside the ken of their conceptualizations to search for causes beyond the immediately observable. Their science could not ask questions bigger than itself. Acting in tandem with Universal Acceleration - "the inherent tendency towards downward motion" - generates the observed effects that spherist call "gravity". 

Inherently, there is no reason to assume that "down" would not exist in space, especially within a finite universe. Consequently, all unsupported objects tend to fall through space at a constant rate of 9.8m/sec. When you jump, being unsupported in space causes you to begin falling downward at a rate of 9.8m/sec. Due to the UA, the earth accelerates up into you. Both the "inherent tendency towards downward motion" through space, and the upward push of the UA against that force, causes objects on earth to remain firmly in place. While the name is slightly misleading, "Universal Acceleration" does not mean that the disk of the earth is continuously accelerating: otherwise it would have reached light speed over 300 years ago. In reality, the inherent tendency towards downward motion counters the upward acceleration of the earth, keeping its momentum constant.

Question: If Earth Is Flat How Do You Explain Lunar Phases And Lunar/Solar Eclipses?

Answer:

https://upload.wikimedia.org/wikipedia/commons/f/f8/Sun_tmb.gif

The above gif loosely illustrates how the sun and moon orbit above the surface of Earth. The sun, moon, and stars are smaller and much closer to the earth. In reality, their geometric relationship is constantly changing. Imagive looking at the above gif from a lateral side view: both sun and moon move upward and downward over the course of a year as they circle the north pole (center of the disk). But this circular course is not locked as the gif illustrates: the sun's circular course widens and contracts, causing earth's seasons. 

The lunar phases depend in part upon the positions of the sun and moon, as well as an observer's position on earth's surface. However, lunar and solar eclipses are primarily caused by a wonderful and truly amazing part of nature: the Shadow Object. Essentially, the Shadow Object is a second moon that is never illuminated by the sun: therefore it cannot be seen by the naked eye. It orbits above the earth, but its path is irregular and less understood. It becomes visible, however, during a lunar or solar eclipse as it interposes itself between the sun and moon, causing the sun to cast its characteristic red shadow on the lunar surface. A solar eclipse occurs when the shadow object moves between the observer and the sun.

Question: If Earth Is Flat, Where Is The Edge? Why Has No One Made It There to Take Pictures?

Answer

The edge is composed of ice and tundra. It encircles the disk and holds the oceans in. It is what sphereists call "the south pole" or the Antarctic "continent". So why hasn't anyone been to the edge? You have to remember that atmosphere functions differently on a Flat earth. Earth is not a ball that that magically glues people and atmospheric gases to its surface. The ring of tundra and ice that encircles the earth extends outward for many thousands of miles. Before you can even "see" the edge, oxygen levels become less than those at the summit of Mt. Everest. Any attempts to reach the edge would necessarily end in tragedy.

Well, why don't we just fly there or send a probe? Good question. Just as oxygen and temperature decrease the closer you get to the edge, the interaction of earth's atmosphere mixing with the atmosphere of space (yes, space probably has an atmosphere of some sort) causes violent winds that would make any such attempt futile. Of course, perhaps the government has "seen" the edge. But it is doubtful we would ever hear about it given the 18 billion dollar budget NASA regularly receives and that fills the pockets of an elite few.