I’m relatively new to Physics Forums, so please go easy on me guys. I’m trying to get an understanding of the so-called Block Universe concept and its implications, but I need help. I’m going to start out by articulating my current understanding, and then try to apply this understanding to develop some interpretations (which may or may not be correct). I welcome your comments and criticisms. My understanding is that, inherent in the Block Universe concept are the following three features: 1. the acceptance of time as a bona-fide spatial dimension, within the constraints of the Minkowski metric. 2. the requirement that all physical objects, both animate and inanimate, travel along their world lines at the speed of light. 3. The notion that all events occurring along an object’s world line exist simultaneously (in a 4D sense) and are equally real. The only true axiom on this list is the first. The other two features seem to follow automatically from the predictions of the Lorentz Transformation. Now for some interpretations: In connection with feature 3, if all the events in a person’s life exist simultaneously in a 4D Block Universe and are all equally real, then it would seem to me that the only way this can happen is if there exists a continuous sequence of younger- and older versions of this same person strung out along his world line. For a person of a specific age, the younger versions must be situated behind him on his world line, and the older versions must be situated ahead of him. The actual distances between these versions can be calculated as the differences in age times the speed of light. But all the versions would exist simultaneously. It would also seem to me that this very same type of interpretation can be applied not only to animate objects, but also to inanimate objects. Thus, in the case of the usual Train Example, if I am an observer in the S frame of reference on the ground and the train represents the S’ frame of reference, the middle of the train might be directly opposite me, and exhibiting a clock time of t’; but there would be another observer within my ground frame of reference further up the track that sees a clock in the caboose that exhibits a time reading greater than t’, and still another observer further down the track that sees a clock in the locomotive reading a time less than t’. Under this interpretation of the Block Universe concept, the clock in the caboose would be “older” than the one I see opposite me, and the clock in the locomotive would be “younger” than the one I see opposite me (assuming that all three clocks were fabricated at the same time in the S’ reference frame). It would also seem that, in this Block Universe model, the rate at which each version of a person is aging is exactly one year for every light year of travel along his world line. As a result of this feature, from the perspective of a “stationary” observer viewing the Block Universe from outside, nothing within the Block Universe would appear to be changing. Younger versions would replace older versions at precisely the right rate so that the Block Universe would seem to be in a permanent condition of steady state equilibrium…frozen. The reality, however, would be much more dynamic than this. There would be a continuous flow of younger and older versions of each animate and inanimate object along each world line. The flow of all the various versions of objects along each world line at the speed of light would also seem to translate into a continuous steady flow of mass along that world line. The sum total of all these continuous mass flow rates along all the world lines throughout hyperspace would represent an enormous continuous rate of mass flow. Where could all this continuous mass flow be coming from? The only logical answer, if we trace the flow back to its source, would seem to be the big bang. But, the big bang has always been viewed an instantaneous isolated mass injection event that took place ~14 billion years ago. The Block Universe interpretation of the big bang would appear to markedly differ from this. It would imply that, rather than representing an a single isolated injection event, the big bang could be viewed as an ongoing event representing a steady continuous point source of mass flow into 4D hyperspace… a sort of a black hole in reverse (in a 4D sense). This completes what I wanted to discuss. Please give me feedback on whether my general understanding of the Block Universe concept is in any way correct, and if the interpretation I have presented makes any sense whatsoever. Thank you.