Conformally Compactified Minkowski Spacetime and Planck Constant

Abstract

If the geometrical system of units c = G 1 and the Planck length as a natural length scale are used in the construction of the Penrose space (diagram) corresponding to Minkowski spacetime, the presence of the Planck constant ħ in the Penrose dimensionless time (ζ) and radial (ρ) coordinates is unavoidable. This fact suggests that there could be a deep and still unknown relation between the spacetime of special relativity and quantum mechanics.