Hello there! I asked this question in a different forum, and was directed to ask this here: ---- My next question also involves Einstein. It's about gravity not really being a force or whatever. According to the program the earth revolved about the sun because the sun warps the space time around it. So if I drop my cell phone and it hits the earth, is this because the earth warps the space time around it? I don't understand this part. Thank you kindly AYCHAMO ---- I received this answer from HallsofIvy which I really don't understand. May someone break this down for me? -- Geometrically, any surface or "curved" 3 dimensional volume has "geodesics" that act like straight lines: they are the shortest distance between points. Gallilean relativity says things move in a straight line unless acted on by an external force. Einsteinian relativity says things move in a geodesic unless acted on by an external force. Since we are used to "thinking in straight lines", when we see things move on a geodesic that is not a straight line, we interpret it as a force. For normal experience it doesn't matter which "model" you use but very precise experiments indicate that the "curved geodesic" model works better than the "force" model. You might get better answers by putting this in the "special and general relativity forum". -- Thank you!