here's an explanation of gravity http://www.amazon.com/Gravitation-Physics-Charles-W-Misner/dp/0716703440/ref=pd_bbs_sr_2?ie=UTF8&s=books&qid=1215294514&sr=8-2

here's an explanation of gravity http://www.amazon.com/Gravitation-Physics-Charles-W-Misner/dp/0716703440/ref=pd_bbs_sr_2?ie=UTF8&s=books&qid=1215294514&sr=8-2 http://www.amazon.com/Gravitation-Physics-Charles-W-Misner/d... long story short, gravity is the curvature of spacetime. objects of mass cause the curvature, and the curvature in turn causes objects to move locally along geodesics (shortest-distance paths), which causes the curvature to shift when you throw a ball and it's moving through a parabola, that curve taken with time in a riemannian space is actually the straightest line possible from one end of the throw to the other this is Einstein's magnum opus General Relativity