Still, if the Earth is the bottom of the universe, gravity would not work. In gravity, the larger the mass, the larger the force of attraction. In your model, gravity will not work, it must be something else, and it shows the same lack of spacial reasoning I see with many here. If the Earth were the bottom of the universe and it is infinite or near infinite, gravity would say that it would have infinite force, meaning infinite acceleration. Light would not even leave the surface of the Earth. And being spread out, basically infinitely with this infinite force, it would collapse the universe onto itself and also pull into itself to a singular point.
The things fall argument is very much like the if the Earth was round we would slide off of it. This is a complete lack of understanding for how gravity works. Yes we do not know the exact cause on the quantum level for gravity, but we do know that it is there, what controls the strength of its force, can measure it, etc. We know that if a mass is sufficient enough (depending on the substance's pliability) it will form into a sphere. There is no force pulling "down" in the universe, there is a force pulling matter to matter.
So for an infinite plane, a disc, a cone, whatever shape you want to think the Earth is other than a sphere, you must not accept gravity. Which is in fact some of the discussions going on here, as most FErs understand this fact, that gravity will not work for their model, hence universal acceleration, denpressure, and whatever the newest aether property is.