Final answer:
Natural motion in curved space follows paths known as geodesics, a concept stemming from Newton's laws of motion extended to the realms of General Relativity and two or three-dimensional kinematics.
Step-by-step explanation:
Natural motion in curved space is called geodesic motion. According to Newton's laws of motion, an object will maintain its state of rest or uniform motion in a straight line unless acted upon by an external force. This straight-line motion is considered the natural state of an object. However, we observe that celestial bodies like planets follow curved paths, such as ellipses, due to the force of gravity. In the context of General Relativity, the straight-line path of an object in a flat space becomes a curved path, or a geodesic, in a curved space-time, which is the effect of massive objects like planets and stars warping the space around them. This concept extends to various types of motion in physics, from one-dimensional straight-line motion to more complex behaviors in two-dimensional kinematics and three-dimensional kinematics, such as the movement of satellites or the circulation of blood through veins.