GR and classical mechanics: Magic?

摘要

A new fundamental ingredient is introduced in the study of Asymptotically Flat Einstein–Maxwell Spacetimes, namely the change of coordinate systems from the standard ones constructed from the infinite number of possible Bondi null surfaces to those based on the four complex-parameter set, za, of Asymptotically Shear–Free (ASF) null surfaces. ASF coordinate systems are determined by “world-lines” in the parameter space, za = ξa(τ). Setting a Weyl tensor component, defined as the complex-mass-dipole, to zero, a unique complex center of mass/charge “world-line” is obtained. From this line and Bianchi identities, much of classical mechanics is directly obtained: spin, orbital angular momentum, kinematic momentum, angular momentum conservation, energy–momentum conservation, Newton’s second law with Abraham–Lorentz–Dirac radiation reaction, Rocket force and Dirac g-factor.