If Hubble's constant = 160,000 m/sec/million light years and c = 299,792,458 m/sec, then shouldn't any two points in the universe farther than about 1,873,000,000 light years apart be expanding away from each other faster than c? Since light from sources much farther than this has reached us, does this suggest that H has been increasing since the Big Bang? Why does the Minkowski spacetime interval not need to take into account H? E.g., Since light can never reach from one point to another that is expanding away faster than c, there can be no lightcone on which they both lie. Does this preclude all simultaneity, mean that each will only ever exist in the other's past or future?