Relativity without Relativity

We give a new derivation of general relativity based entirely on three dimensional principles. We start with a parametrisation invariant, Jacobi-type action on superspace. This will be the product of a square root of a potential times the square root of a kinetic energy term. All we demand is that the action have nontrivial solutions. We find that the only viable action is the Baierlein, Sharp, Wheeler Lagrangian and thus we recover G.R. We impose no spacetime conditions whatsoever. We extend this to include scalar and vector fields. We recover causality (everything travels at the same speed), Maxwellian electrodynamics, and the gauge principle. Thus we derive a large part of modern physics from a purely three dimensional point of view