Consider the resolution of the human eye and its ability to distinguish two points at a distance. This is observed by the converging lines of perception forming a "false horizon" and easily proved by laying on your stomach in a field and watching someone walk away from you (you could use a camera too). Your angle of view determines the convergent point for the false horizon. This phenomena would be observed on both a sphere model and on an infinite plane model. LOL nigger, you just walked into my first point When you lay down to watch the sunset over the ocean you angle of view is such that the waves between you and the sun become indistinguishable from eachother and converge into a "false horizon". When you stand up and see it again you actually just proved my point. When you stand your angle of view changes and so does the distance to this "false horizon" which is created because of the biological limitations of your human eye lack the RESOLUTION power required to distinguish this two points as being Separate. When a ship disappears bottom first, it is because of the ocean waves between the observer and the bottom of the ship are two points that no longer become distinguishable from eachother and hence they "converge" into a false horizon. This is proved by watching a ship disappear with your own naked eyes, only to be brought back into view with modern viewing equipment. How could modern viewing equipment do this? Resolution of the equipment verses the resolution and biological limitations of the human eye. The equipment as a higher resolution and as a result it can distinguish two points with greater clarity. All of this is observed at a range well under the needed distance to get the SAME effect out of the actual curvature of the earth. Meaning; most people attribute the "bottom up" effect to the actual curvature of the earth where in fact it is actually due to their perception alone. The height required to actually observe the curvature of the earth is over 40k ft. All arguments saying the curvature of the earth is proven by x object disappearing are false conclusions.