Hello everyone, Recently I realized what momentum refers to in reality. Briefly: On the perceptual level it refers to the phenomenon which enables an entity to continue motion even after the cause of the initial motion, either by direct contact or via field, no longer affects it. It is distinct from the concepts of motion and velocity(a rate) in that it describes that cause/force 'within-it-self'(a transient attribute)allowing it to continue motion(which is why it is proportional to mass). This is such a common aspect of daily experience that I've never thought of it(even with the definition of inertia in-mind) as a separate phenomenon requiring explanation - that is, that this motion is not a necessary consequence; one could just as well expect the motion not to continue. And with this realization came the following questions, I'd appreciate help with: 1 - Is it experimentally demonstrated that this attribute is not self-dissipative(perhaps in the form of some radiation...) as apposed to being purely resisted by opposing forces(air resistance, surface friction) - that is, if it is not a mixed case? And if so, doesn't this imply the possibility of perpetual motion? 2 - What makes it possible for an object to continue this motion? Thanks.