Okay. That pretty much answers my question. Distance was left-out as an approximation, although it seems obvious to me, in retrospect, that it is not a good enough approximation. But I know the rules.
When someone outside academia offers a solution to a vexing problem, he or she is ignored at...
I do not understand the first part. As for the latter, your point seems to be that things are even more complicated than I've made them out to be. Neither part answers my question: Why not employ a more realistic model--one that includes the amount of "spacetime" between clumps--when the one...
The standard answer: “In GR, only average density matters.”
That is what Friedmann’s equations (1) say—mathematically—but he does not derive that conclusion. He starts with it.
Friedmann does not start with a messy, real-world model of the universe, one that has fractured into galaxy clusters...