#92 A comparison diagram of the gravitational field strength of typical inverse square gravity versus hyperbolic 1/kr gravity illustrating Birkhoff's Theorem that states gravity must be asymptotically flat, that is, it must display no asymptotes. This means that, for a perfectly spherically symmetric gravitational field, no asymptotes are possible. That is, it must follow an inverse square law and cannot be hyperbolic. No real black hole is anywhere near spherically symmetric, however. And, they are always grossly distorted by external gravitational fields. So, the theorems do not apply and are good only for approximate computations, not for "precision cosmology".