Well, since I've decided to aid 6string in his quest to help the Flat-Earthers develop better arguments and defend their beliefs in a logical way, I have decided to start posting better explanations for certain phenomena for which the current falt-earth explanation downright sucks. I'm sorry, but "atmospheric conditions" just doesn't cut it.
The first is gravity. Gravity as explained by current science is the attraction of small masses towards a large mass's center. Like people to a planet. This is why on a spherical Earth if you were to dig straight down, you would start going up after you hit the center. On a flat Earth, gravity could very well work in exactly the same way.
My theory is that the Earth actually sits on a much larger mass, possibly another disk, but very close to the center. I have made a diagram to demonstrate:
In this model, the red lines represent gravity. The force is still pulling towards the center of the disk, but the Earth is so close to the center on the surface, that the angle at which gravity pulls is practically non-existant.
Some of you might say "Well then why haven't we noticed the angle? I notice when I'm on a slight incline". The answer is evolution. Don't say evolution is just a theory, it's not. It happens, it's real, and it's still happening. The only part of it which is under debate is whether or not we come from apes. So, anyways, the purpose of evolution is to adapt to the environment. If it's hot our skin darkens, if it's cold, animals grow fur, if the entire world seems to be at a slight incline, our balance is adjusted to compensate.
Also, when the body is subjected to something constantly and it is out of the ordinary, the body normally tries to fix the problem. I remember hearin of an experiment where people were given special glasses which mirrored the image and made it seem as thoguh everything were upside-down. After a period of time, all of them adjusted and their brains automatically compensated and reversed the image.
The same occurs when there is a smell in the air for a long time. After an hour you won't smell it, but it's still there. You just "got used to it". The same goes for sound. Sometimes I like to set my watch to beep every second just to piss people off and after a while, you don't hear it anymore unless there's either a long, dead silence or you try to hear it.
"Getting used to" something really means that the body, mind, or both have adapted temporarily to the environment to help make you more comfortable. It's pretty much temporary evolution. The same thing happens with the angle of gravity. We've gotten used to it, and since the angle is always there, the adaptation has become permanent. We have, effectively, evolved to compensate what could be perceived as a slightly tilted Earth.