The discussion revolves around seeking modern references for classical gravitation treated as a field theory in flat spacetime. Participants share various resources and express thoughts on the implications of the flat metric in relation to observable phenomena and theoretical frameworks.
Participants present multiple competing views regarding the implications of the flat metric and its observability, as well as the treatment of black holes within this framework. The discussion remains unresolved on these points.
There are limitations regarding the assumptions about the observability of the flat metric and the dependence on specific definitions of gravitational theories. The discussion does not resolve how these theories relate to black holes or the implications of the proposed approaches.
abstract said:A pedagogical description of a simple ungeometrical approach to General Relativity is given, which follows the pattern of well understood field theories, such as electrodynamics. This leads quickly to most of the important weak field predictions, as well as to the radiation damping of binary pulsars. Moreover, certain consistency arguments imply that the theory has to be generally invariant, and therefore one is bound to end up with Einstein's field equations. Although this field theoretic approach, which has been advocated repeatedly by a number of authors, starts with a spin-2 theory on Minkowski spacetime, it turns out in the end that the flat metric is actually unobservable, and that the physical metric is curved and dynamical.
Short sections are devoted to tensor-scalar generalizations, the mystery of the vacuum energy density, and quintessence.