the light not left behind as the rest of the matter passes on along the 4th dimension? Why can we still detect light that appears to have been travelling across space for light years?" I am not sure I understand what you are asking. The fourth dimension is expanding relative to the three spatial dimensions at c. Light stays at one place in the fourth dimension while moving at c. Ergo, the fourth dimension must be expanding at c relative to the three spatial dimensions. This is a most beuatiful, simple postulate and theory. Simple proofs of MDT: PROOF#1: Relativity tells us that a timeless, ageless photon remains in one place in the fourth dimension. Quantum mechanics tells us that a photon propagates as a spherically-symmetric expanding wavefront at the velocity of c. Ergo, the fourth dimension must be expanding relative to the three spatial dimensions at the rate of c, in a spherically-symmetric manner. The expansion of the fourth dimension is the source of nonlocality, time and all its arrows and asymmetries, c, relativity, entropy, free will, and all motion, change, and measurement, for no measurement can be made without change. For the first time in the history of relativity, change has been wedded to the fundamental fabric of spacetime in MDT. PROOF#2: Einstein and Minkowski wrote x4=ict Ergo dx4/dt=ic. PROOF#3: The only way to stay stationary in the three spatial dimensions is to move at c through the fourth dimension. The only way to stay stationary in the