Quantum nature of gravity and spacetime: Fundamental insights from the Hoyle-Narlikar theory

The Hoyle-Narlikar theory of gravity, an action-at-a-distance formulation, is highlighted for its mathematical rigor and incorporation of Mach's principle. It proposes that two-point functions are more fundamental than the metric in determining spacetime structure. This theory offers insights into quantum spacetime, suggesting a non-local description where the universe informs local causal structure at the Planck scale.