If time’s dimensionality is similar to or the same as the dimensionality of a direction in 3 dimensional space, then what is the underlying nature of time? Minkowski’s space time concept implies that the 4th dimension (which he assigns to time) should be treated as just one more of 4 dimensions for a 4 dimensional metric. The 4/3 law implies the same thing particularly with respect to the equipartition of energy. The 4/3 law appears to account for dark energy. Is time a shadow (of the underlying reality) cast on the cave wall? If it is, what is it a shadow of? Expansion of the universe?