First, picture a marble orbiting Earth. Now, get the idea of orbit out of your head. Put a huge ring around the outside diameter of a marble's potential orbit in space, and connect a mechanical hand to this ring, which holds the marble suspended above Earth. How does space know that this Earth/ring/marble system is not already spinning as a unit? If it is already spinning as a unit, then the marble will experience some outward force. The ability to measure relative motion by looking, visually, at other objects is not an answer to how space knows whether the marble is supposed to be in a geocentric orbit, or whether simply the Earth is spinning while the marble is carried round and let go to fall to the ground. The mechanical hand lets go of the marble. What happens? How does space and, or matter, know whether there is orbit or not? The fact that we do send objects into orbit does not answer the basic question.