[GiantTurtle]

So it doesn't matter whether the disk is infinite or finite - there could still be no air (or water) in the habitable part.

Actually no, there would be infinite air there as well.
Infinite space, infinite mass, pushed to near light speed an infinite force, this is the only place where finite exists and only finite exists.

[Mark_1984]

Have to agree with both points.  For an encore, let’s ask them why the planets are spherical if there’s no such thing as gravity ?

[Rama Set]

According to their wiki, there is a 3rd alternative. The atmosphere is held in by a dark energy field.  However, there are two flaws (at least) with that hypothesis. We can detect dark energy directly as it doesn’t appear to interact with normal matter, and hence doesn’t interact with air.  We only know of the existence of dark energy because the universe is expanding faster than Gravity should allow.

UA, by itself, perfectly explains why the air stays glued to the ground and decreases in pressure with altitude.   They don't need to invoke "dark energy" or invent new theories.

What they have already is perfect.   Adding more uneccessary bullshit to it just makes their case worse!

Actually, I can't think of any good reason why they need UA either.   If the Flat Earth is infinite (claimed in a bunch of places) then good old fashioned gravity works just fine for the Flat Earth...that's by far the simplest explanation and results in the fewest problems for their cause.   Heck, we can even explain the reduction in gravity at the tops of mountains perfectly if they do that.

The only reason you need UA is if the Flat Earth isn't infinite...but it doesn't even have to be totally infinite - it can just be much larger than the part we've explored.

I think the FE'ers tend to over-compensate for things that they don't think their hypothesis explains - when really it does just fine.

The infinite disc gravitational field also creates a convergence of bending light beams directly above its center, so it is not a perfect solution.

[3DGeek]

So it doesn't matter whether the disk is infinite or finite - there could still be no air (or water) in the habitable part.

Actually no, there would be infinite air there as well.
Infinite space, infinite mass, pushed to near light speed an infinite force, this is the only place where finite exists and only finite exists.

But then it would take infinite energy to keep it all from freezing...and all you have in one puny 31 mile diameter sun.

Nope - doesn't matter how much air there is - all of it freezes.

[Rama Set]

An interesting link that talks about horizons and gravity on an infinite flat Earth.

http://www.askamathematician.com/2012/08/q-if-earth-was-flat-would-there-be-the-horizon-if-so-what-would-it-look-like-if-the-earth-was-flat-and-had-infinite-area-would-that-change-the-answer/