ILikeAnswers said:
My question is, why do these objects even rest on space in the first place? It's as if there's a downward pulling force in space itself. There must be something other than gravity pulling objects down because otherwise, orbits won't exist.
Spacetime is a host habitat in which physical fields, particles, photons reside. Any physical entity has the property of a location in spacetime specified by x,y,z,t. In an orbit around a mass such as earth, the path of an orbiting body like the moon is a 2-D geometric object, either ellipse or circle. But in order to visualize spacetime, we need a time axis. So we can use the plane of the orbital path to visualize a 2-D space with time axis perpendicular to it (a 3-D spacetime). Picture a 3-D cartesian axis system where Earth is centered at the origin with x,y as a horizontal plane and the orbital path of the moon is embedded in the plane. The plane is at t=0 and the time axis rises vertically.
The Earth's path in 3-D spacetime, from its own perspective, is having no motion in the plane and rising vertically through time spontaneously, so it sweeps out the time axis. The moon, however spirals upward in an elliptical motion around the Earth (and the time axis itself as well) as it passes through time. The spiral is itself the distortion of the 3-D spacetime from the motionless Earth that has nonzero velocity only along the time dimension. The moon's spiral path is called a geodesic which is thought of as a path through spacetime that an object may travel by momentum only (i.e., no external forces are pushing on it as seen from the object's own perspective). From the object's perspective, it is in weightless space (often called freefall). There are a continuum of geodesics around the Earth so that objects of different mass and orbital velocity will be in freefall at different radii. These geodesic spirals are all collectively the total distortion of spacetime from the perspective of the earth.
Compare this view with Newtonian (classical) space-only-gravity where the object in orbit is pulled by gravity toward the center of the earth, but is moving so fast tangentially to the pull that the physical surface of the Earth below falls away before the pull of gravity can divert the object from its tangential path and steer the object into the Earth's surface. Instead the object is diverted just enough to stay in orbit. Time is irrelevant in this picture, there are no distortions of space or time, and forces on the moon are nonzero.
There is one additional complication. Both the Earth and moon have mass and each distorts spacetime. There is a point on the line between the center of each of these two masses (a lagrange point and center of total mass) where it can be said that both the Earth and moon are each in orbit around and spiral around this point. Here we are ignoring the pull of the sun, galaxy, and other influences and just considering the isolated earth-moon pair. In this case the distortion of spacetime is visualized by a test mass, whose own distortion of spacetime is negligible, that is launched at various velocities and angles through the earth-moon system and its many possible geodesic paths recorded.