If Gravity is not a "force", then how does this work? This has got to be a question with a simple answer. But I can't figure it out. I understand that Einstein demonstrated that gravity is not a "force", as was contemplated by Newton. Instead, gravity alters the geometry of spacetime. I understand how this affects the path of an object traveling close to a large mass. The object "thinks" it is following a "straight line", but the space in which the object is located is curved by the mass, so that the straight line becomes curved from the perspective of an observer comoving with the large mass. I can visualize that. But this I cannot understand: If an object is at rest with respect to a large mass, comoving in an inertial frame of reference with respect to the large mass, why does it approach the large mass absent an external force applied to the object? Imagine a rock supported on a platform. It is stationary with respect to the earth. If the platform is removed, the rock will move towards the center of gravity of the large mass. Why? Again, I understand how curved space can alter the trajectory of an object that passes near a large mass. In that case, the straight line the object would otherwise traverse follows the warped space, and the object will veer towards the large mass. But if the object starts out stationary with respect tot the large mass, and if there is no force to move the object, why does it fall? The object exists and is stationary with respect to the mass within the curved space. But what makes it move with respect the the center of gravity if it was originally stationary? How can gravity not be a "force"? Do I simply misunderstand the definition of "force"? When Einstein denied that gravity was a "force", did I misunderstand what was said in some fundamental manner?