The law of Universal Gravitation states that "every single point mass attracts every other point mass by a force heading along the line combining the two. The force is proportional to the product of the two masses and inversely proportional to the square of the distance between the point masses"
F=G*{(m1*m2)/r^2}
Where F = Gravitational Force, G = Universal Gravitational Constant, m1= Mass object 1, m2= Mass object 2, and r = separation between objects.
This has been demonstrated to be correct experimentally, and has been replicated using two dense spheres, so please do not waste time arguing that the experiments were faked, or that the scientists were bribed. It has been verified. That is not a point of contention.
Now, this can be applied to an object on the surface of the earth, exerting and being the subject of a force.
Applying Universal Gravitation to this requires a slight altering of form:
Weight (F) = G*{(M*m)/r^2}
Now, using the accepted model of a Spherical Earth, and using a sphere of 1 kg in mass for simplicity, to determine its weight:
G=6.67300 × 10-11 m3 kg-1 s-2
M(Mass of earth)=5.9742 × 10^24 kg
m(Mass of object)=1kg
R(Distance from object to centre of earth/radius of earth) - Note, assuming radius of object to be negligible. Within margin of error for measurement of earths radius anyway. = 6 378100 m
Weight = 9.7998kg·m/s²
This is what is to be expected, as weight = mass * gravity.
Now, I hope none of you are going to argue the toss here either.
When we try to apply this valid model to the Flat Earth, we are presented with a massive problem. You have two options; to decide to deny gravity and go along with your model of the earth accelerating "up" at 9.8m/s, or to accept gravity exists. Either way your model is invalidated.
Option 1 - Accept Gravity:
As I have demonstrated, gravity is affected by the distances between objects. More precisely, their centres of mass. Your model would have objects at the edges of the earth and objects over the centre of mass weighing ridiculously different. Not the case.
Option 2 - Deny Gravity, and go along with Up at 9.8m/s.
Problem. Big one. Gravity can be demonstrated, has been demonstrated, reproducibly and independantly at different height above sea level. And guess what? Just as Newtons model predicts, the value for gravity changes. The value for at sea level is 9.8m/s, the value at the peak of everest is .2m/s less. Your model does not explain this. It has been demonstrated thousands and thousands of times that gravity is proportional to distance from the earth's centre.
I dont see any logical fallicies in my post, I'm sure you will be quick to point the out if I have. And bullshit explanation from Tom Bishop aside, I dont think you can explain this with your Flat Earth model. Q.E.Fuckin.D.
Edit-corrected units, not that it matters