Final answer:
Sir Isaac Newton discovered the force that causes objects to fall to the ground and also keeps planets in their orbits.
Step-by-step explanation:
Sir Isaac Newton was the first scientist to precisely define the gravitational force and show that it could explain both falling bodies and astronomical motions. He proposed an exact mathematical form, which demonstrated that the motion of heavenly bodies should be conic sections, such as circles, ellipses, parabolas, and hyperbolas.
Newton's discovery of gravitational force not only explained the motion of objects falling to the ground but also provided an understanding of the force that keeps planets in their orbits around the Sun.
This theoretical prediction was a major breakthrough, as it provided a mechanism that caused heavenly bodies to follow specific paths, based on empirical evidence and mathematical equations.