to better understand the expansion of universe, i probably need to see a well designed animation. neither in stretching rubber nor inflating baloon models i don't understand how does Hubble constant of 74kps fit on them. actually to apply Hubble constant i can only imagine one model and that is either overlapping or free falling, but then i can't see any expansion at all. so, i have to think more to imagine how our universe is expanding with speed rate of 74kps/per megaparsec. animations would be helpful.