What if the world was flat?
No, I'm quite aware the Earth is a sphere. You're just preaching to the choir trying to explain to me that its round. Nor am I trying to support the Flat Earth Society.
- What would it take for the world to be flat?
- How would there be gravity?
- How would the atmosphere stay in?
- How could a day/night cycle be done?
- Are seasons possible? What season would it be?
and any other questions that may arise.
For the sake of argument, picture a large flat dish. To create gravity on the surface of this dish, you need something under it exerting a force down. The easiest way to do this is to put a large mass under the surface. This mass should be spread out so that all the dish gets a downward force. As an intresting note, you could also think of this as a sandwich because a force will also be pulling at the other side.
To have an atmosphere, you just need a wall around the edge of the dish (a la Ringworld). Gravity holds it nicely down and makes sure it dosn't escape.
A day/night cycle is more difficult. It involves either spinning the disk like a penny on a table (which will cause problems with the above atmosphere) or moving the sun either up and down or orbiting the dish. Neither are trivial.
I have no clue if seasons are possible.