par Pierseaux, Yves
Référence Annales de la fondation Louis de Broglie, 27, 1, page (19-67)
Publication Publié, 2002
Article révisé par les pairs
Résumé : Planck developed not only the relativistic thermodynamics but he deduced also the equation of the relativistic dynamics (of mass points and mass bodies) from Einstein's electrodynamics and Helmholtz's principle of least action. This latter is a non Hamiltonian principle which gives an essential role to the function of state entropy. Poincaré obtained the same equation, one year before (1905), from the Hamiltonian principle of least action and the introduction of a potential in the Lagrangian of the classical electron. This pressure of ether is not a supplementary hypothesis but means only that Poincaré's implicit kinematics of deformable rods is not based on the same principles as Einstein's explicit kinematics of rigid rods. Poincaré's two principles (principle of relativity and principle of real contraction) are as compatible as Einstein's two principles. The sterile polemic of priorities is scientifically overtaken. Indeed the contrast "Einstein-Planck special relativity with invariant entropy" and "Poincaré's special relativity with invariant action" is inscribed in two fundamentally different uses of the Lorentz transformations and two fundamentally incompatible conventions (classical or quantum) for the definition of space-time units of measure.