Einstein was Wrong: Newtonian Dynamics Can Disagree Completely with Relativistic Dynamics at Low Speed

Abstract

According to Einstein, the trajectory of a particle that is predicted by special relativistic mechanics is well approximated by the trajectory predicted by Newtonian mechanics if the particle speed is low, i.e., much less than the speed of light. However, in this paper, it is shown with a counterexample Hamiltonian dynamical system that Newtonian dynamics can eventually disagree completely with relativistic dynamics even though the particle speed is low. After the breakdown of the agreement, either the Newtonian description is no longer correct or the relativistic description is no longer correct or both descriptions are no longer correct for the low speed motion.