Inertial Forces and the Laws of Dynamics
The basic concepts and laws of classical dynamics are analyzed from the standpoint of their adequacy to the physical nature of material bodies and to the dynamical processes. What Newton called absolute immovable space is the world ether that generates any forces, including the inertial forces imposing constraints on the magnitude of the acceleration. Inertial reference frames are framed moving translationally, rectilinearly, and uniformly relative to the ether. The physical nature of the principle of relativity is that the acceleration of a material point in all inertial reference frames coincides with its acceleration relative to the ether, and, therefore, Newton's dynamical equation retains the same form in any inertial reference frame. The principle of relativity is valid as long as Newton's dynamical equation is valid. In new formulations, the four laws of dynamics contain the concepts of ether and inertial forces. These laws are independent of themselves, and each of them expresses only one elementary truth.