Held to this standard, General Relativity is incomplete. GR’s curvature is simply the direct, instantaneous consequence of the stress-energy tensor. There is no cost, no conversion process, and no deeper mechanism or force that makes spacetime curvature occur.

4DKC is a viable, developing framework that is, at its base, not that complicated. It is based on a few postulates. The universe is a flat four-dimensional spatial manifold (x, y, z, L) where L is a large, non-compact spatial dimension with electromagnetic character. Locally observable 3D space is a hypersurface moving through L at c. Electromagnetic binding continuously extracts kinetic energy density from this flow, creating deceleration gradients that we experience as gravity.

This answers a simple but profound question: If Earth is accelerating outward at every point on its surface, where is it accelerating to? The answer is a direction in L.

The theory makes clear, falsifiable predictions, including subtle directional variations in the one-way speed of light along deceleration gradients.

It explains all observed cosmological phenomena without a Big Bang, space-time curvature, singularities, dark matter, or dark energy. Black holes become finite kinematic regions where the manifold flow simply slows to zero. The same mechanism naturally produces flat rotation curves, the radial acceleration relation, cluster-merger offsets, and the arrow of time - all from ordinary electromagnetic binding in a single 4D spatial manifold.