Placing the Hyperbolic Geometry of Bolyai and Lobachevsky Centrally in Special Relativity Theory: An Idea Whose Time has Returned

Newtonian and relativistic kinetic energy: analogous consequences of their conservation during elastic collisions

“…Hence, as Sonego and Pin point out, all the differences between Newtonian and Einsteinian kinematics and dynamics boil down to the difference between the common vector addition of classical velocities and the Einstein addition of relativistically admissible velocities. The central role that Einstein velocity addition plays in relativity physics, already pointed out in [15] and indicated in [16][17][18][19], is thus obvious.…”