Newton's law of inertia and time
  A closer look (with hindsight) at Newtonian and relativistic kinematics reveals two things. Not surprisingly, Newtonian time remains the empty and artificial - albeit useful - figment it is known to be. Quite unexpectedly however it turns out that with an only slightly more physical time-concept, time and space remain separate entities and simultaneity of events becomes a meaningful concept even for physicists. 
Chris Leemann