Flat Earth Society

The curvature definitely makes a difference - otherwise satellites wouldn't stay in orbit.Consider the following childish drawing. The blue lines are the velocity vector at time A, the yellows at time B. The red lines are supposed to represent acceleration towards the centre of the earth due to gravity, In the round earth case, the satellite is being accelerated towards the centre of the earth, but due to it's momentum orthogonal to the earth doesn't approach the surface, since the surface is curving away. Putting an object in stable orbit is all about calculating the right forward (orthogonal to the radius of the earth) speed (square root of the acceleration due to gravity multiplied by the distance to the centre of the earth).In the flat earth case, in contract, acceleration due to gravity would eventually bring the satellite crashing to the ground regardless of it's speed (unless it overshot the edge).By my count, a bullet would need to be travelling at only a little over 7.9 km/s a second to achieve orbital velocity and never hit the ground - at least if there was neither air resistance nor pesky things like trees, buildings and hills to get in the way.

Assuming no air resistance, the drop time would be closer to 1 1/2 seconds (sqrt of 2). You're mixing up the downward speed and the downward acceleration.

This one actually intrigues me. Can a fat man actually fall slower by presenting a bigger surface area? My Physics 101 knowledge never got as far as dealing with air resistance.