  For the Newtonian N-body problem, we study the Jacobi-Maupertuis metric of
the nonnegative energy levels. We show that the geodesic rays are expansive,
that is to say, all the distances between the bodies must be divergent
functions. More precisely, we prove that the evolution of such motions
asymptotically decomposes into free particles and subsystems in completely
parabolic expansion. The theorem applies in particular to the maximal
characteristic curves of any given global viscosity solution of the stationary
Hamilton-Jacobi equation $H(x,d_xu) = h$.
