love_444 (Mariana V.I.P): This is referred to as the Newtonian principle of relativity or Galilean invariance. *26-12-07 - 20:10:57
love_444 (Mariana V.I.P): Newton’s laws of motion must be implemented with respect to (relative to) some reference frame. A reference frame is called an inertial frame if Newton’s laws are valid in that frame. Such a frame is established when a body, not subjected to net external forces, moves in rectilinear motion at constant velocity. *26-12-07 - 20:13:50
love_444 (Mariana V.I.P): The wave nature of light seemed to require a propagation medium. It was called the luminiferous ether or just ether (or aether). *26-12-07 - 20:20:56
love_444 (Mariana V.I.P): Ether was supposed to be invisible, mass less, perfectly transparent, perfectly non-resistive and at absolute rest. It had to have an elasticity to support the high velocity of light waves. And somehow, it could not support longitudinal waves. *26-12-07 - 20:24:03