Is Earth really "floating in the middle of nothing", or, is there some other invisible

force that keeps it, and all of the other objects in our solar system, orbiting around the

sun?

Gravitational force, electromagnetic force, weak nuclear force and strong nuclear force. - Gravitational force is common to all matter: all material bodies attract each other. Gravitational force is the force that works on earth beacuse of the sun mass. And all the smallest object in our solar system are attracted by the gravity force of the sun.