Don't forget Heisenberg's Uncertainty Principle: There is inherent uncertainty in the act of measuring a variable of a particle in motion. The more aggressive the means of measuring a particle's state while traversing a plane, the more uncertain the observations become. The Uncertainty Principle is typically applied to quantum particles in single planes-of-motion but, the general conditions of the principle - that intrusive means of measurement introduce uncertainty - apply equally to Newtonian particles in motion, as well. Things like bullets... It is not possible to know at any given moment in time, with any certainty of precision, which variable or variables in a bullet's path, or which variable or variables in the bullet's movement along that path, is/are affecting its path or movement or to what degree. Even stop-action photography and digital radar/sonar cannot account for all variation at any given moment with no uncertainty. For one thing, we can't see what's happening inside the bullet.