+ ... A killing vector is a vector which which projected on the four vector U = (U_t, U_x, U_y, U_z) is constant K*U = const, where * is basically the vector dot product. So this all works in the flat case, and if works in other spacetimes with curvature as well. But if we bring in the conformal factor a time component of a Killing vector is not constant along the coordinate time direction. So this means that there is no global time "vector field" which can apply on the spacetime which gives isometries (distance preserving transformations). Further, since time and energy, just as position and momentuam, are conjugate variables there is no energy conservation principle which can be defined globally. However, for cosmology a conformal energy conservation can be defined. There are some very deep elements and consequences to this, but that might be for later. Tegmarks declare reality just mathematics. Cantorians declare mathematics free for disposal like a game with arbitrarily chosen rules. Accordingly, neither spr nor smr have to feel responsible for questions concerning very basic discrepancies between theory and reality. Doesn't this let room for endless speculations? Instead of suspecting either Max Tegmark or Georg Cantor wrong, I tend to distrust both. I think I have explained this before. In objective reality there is no time just fluctuating energy and space. In this model, Universal time is not universal in that it is the same for all objects and particles, but in that each object