Most flat earthers seem to deny the existence of gravity.
I have seen some try to explain that objects fall to the ground because of density
But the flat earth society has created a novel idea called Universal Acceleration, whereby the flat earth is accelerating "upward" at the rate of 9.8 m/s^2.
If the whole earth is accelerating at the same speed how does this explain that at higher altitudes (eg on top of a mountain) objects fall at a slower speed?
Obviously on a spherical earth gravity decreases as an object moves further away from the centre of the earth.
But for a flat earth Universal Acceleration fails to explain why the acceleration of falling bodies is not constant at different altitudes.
Any ideas?