Since the bridge (as postulated) would be extremely long, it's also reasonable to suppose that the lines would converge so far that the human eye could not separate them, meaning the bridge would actually recede to infinity (visually.)
Last edited by Gandalf223; 2009-May-22 at 05:01 PM. Reason: Completing my thought...
So; let me clarify that my comment is only perception and could probably be that way due to optical illusion effects, and is totally dependent on the ability to percieve the curvature of the Earth.
So, allow me to add another initial condition, since I think the original problem is quite nicely handled.
Now, take the bowling ball, still on the frictionless surface, and give it a very strong spin, say in a clockwise direction, at 75% of the angular rotation that it can withstand due to centripital accileration, with the spin axis (originally) pointed straight through the center of the earth.
What path will the ball take?