Surprising Structures Hiding at Penrose's Future Null Infinity

Since the late1950s, almost all discussions of Asymptotically Flat (Einstein-Maxwell) Space-Times have taken place in the context of Penrose’s Null Infinity, ${\mathcal{I}}^{+}\mathrm{.}$\ \In addition,\ almost all calculations have used the Bondi coordinate and tetrad systems. \ We show - first, that there are other natural coordinate systems, near ${\mathcal{I}}^{+},$ (analogous to light-cones in flat-space) that are based on (asymptotically) shear-free null geodesic congruences (analogous to the flat-space case). \ Using these new coordinates and their associated tetrad, we \textit{define the complex dipole moment, i.e., as the mass dipole plus i times angular momentum,} from the l=1,\harmonic coefficient of a component of the asymptotic\Weyl tensor. Second, from this definition, from the Bianchi Identities and from the Bondi mass and linear momentum, we show that \ there exists a large number of results

• identifications and dynamics - identical to those of classical mechanics and electrodynamics. They include, among many others, $\mathbf{\text{P}}$=M$\mathbf{\text{v}}$+…, $\mathbf{\text{L}}$=$\mathbf{\text{r}}$x$\mathbf{\text{P}}$, \ spin, Newtons 2nd Law with the Rocket force term (.{M}$\mathbf{\text{v}}$) and radiation reaction, angular momentum conservation and others. \ All these relations take place in the rather mysterious H-Space.